Transnational Intellectual Debates

Iranian intellectual debates resonate far beyond Iran. An elite of Shi'a clerics, religious intellectuals and militants carefully pays attention to what is said, thought and written in Qom, Tehran and Mashhad. The "Islamic sphere" (al-hala alislamiyya) in which they move has no borders and exists wherever individuals meet, exchange information and news they picked up elsewhere, reminisce, discuss and debate. Students of the religious sciences from all corners of the Shi'a worlds visit Qom for a while, then leave again, taking with them knowledge and a certain idea of Islamic modernity which they will transmit to others. For several years they study together, then lose sight of each other, only to meet again by chance during a pilgrimage, a pious visit or any other voyage, in the majlis of a sheikh, the offices of a magazine or publishing house, a research centre, a library, an Islamic foundation... The connections are closest among men who have been circulating for a long time between Persian and Arabic Shi'ism, between Iran, Iraq, Lebanon and the Gulf states, especially Saudi Arabia.

Many of this elite have passed through the hawza, others have studied at universities and more and more numerous are those who completed a double education. Some are autodidacts, others are teachers, students and among them are also women whose numbers and importance are growing. All share the same references to a religious Shi'a culture, a corpus of classical texts and the founding texts of the Shi'a Islamic movement but also of Sunnism.

Nevertheless, they do not necessarily hold the same opinions, each using these shared references to develop a personal point of view, always prone to nuances, reexaminations and pragmatic readjustments in accordance with events occurring and new theories emerging. Should we see in this a characteristic of Shi'ism, where the ultimate aim of religious studies is to practice ijtihad, to forge one's own opinion and defend it, and where the individual, the mujtahid, prevails over the institution? Nothing is more difficult than tracking currents and tendencies, constructing categories that enable us to develop a structured representation of this Islamic sphere.

Actors and observers distinguish between islamists and liberals, activists and quietists, supporters of the regime and its opponents. 1 Meanwhile, the fault lines are sometimes subtle and difficult to determine and supporters of the Iranian Islamic regime have also been influenced by the arguments of reformists, if only to refute them. A good example is the ideas of Soroush, which everybody knows directly or indirectly. While he was the religious intellectual of the Islamic Republic at the time of the reformists, preaching for the individualisation of the faith, Shari'ati has become an authority even within the Islamic movements by advocating the declericalisation of society. These are not contradictions perturbing an otherwise coherent system, but phenomena proper to the Islamic sphere, which is to be understood as a dynamic field in constant movement, crisscrossed by subtle divisions which resist systematic categorisation. Thus, the Shia "Islamic sphere" in Beirut includes milieus that are more or less close to Hezbollah and others that overtly distance themselves from the party. Each side has its own ties to Iran, depending on the positions it takes. They are distributed over both sides of the 'line of the Imam' (khatt al-imam), which Hezbollah adheres to and which is mainly based on the theory of wilayat al-faqih as conceived by Khomeini. But here too, nuances should be made, because a distinction is made between the theory and its application after the Revolution, and many are those who cherish the dream of a return to the purity of Khomeini's intentions -seen as diluted through the exercise of power -in order to reconnect with the ideal which remains the Islamic utopia.

Common History, Shared References

The 'mechanical solidarities' that link the clerical milieus and specifically the elites are still operative today, although newcomers not belonging to the great families "of science" have transformed the landscape. Organic ties, moreover, connect the militants of political parties and other politico-religious formations. But the Islamic sphere also includes individuals with disparate profiles and individual intellectual trajectories who are not affiliated to any established group. The factor which preserves internal cohesion and ensures that every person can recognise the other as 1 The term "quietist" is to be understood here in the sense given to it by Nikki Keddie in Religion and Politics in Iran, namely "withdrawn from political engagement". Cf. Yann Richard, L'Iran. Naissance d'une république islamique, p. 258, note 13. About the neo-conservatives, see Farhad Khosrokhavar, 'Neo-conservative intellectuals in Iran'; about the reformists, see the references in the part 'Iran and its Debates'.

an interlocutor is the common history of the Shia movement, which has produced the references each and every one of them shares. This history has deep-seated roots and spans a centuries-long elaboration of the religious doctrine, with its division between usulism and akhbarism and the victory of the former over the latter. More recent are the premises of the Islamic constitutional movement in Iran (1906-1911) and the debates between the great Shia mujtahid of Qom and Najaf. 2 This is the history of the Shia movement which began in the late fifties and early sixties, as a reaction to the revolution of the Free Officers and General Qasim in Iraq in 1958 and the white revolution of Mohammad Reza Shah in Iran in 1963. Agricultural reforms and the elaboration of a new family code particularly affected the ulemas, whose position had already been undermined by the secularisation of the institutions, the decrease of their income and the slow decline of their religious schools. Moreover, students were tempted by the Marxist ideas that spread in the holy cities and many are those who arrived to study the religious sciences but left without a turban and instead became communists. 3 In answer to these threats, the clerics, the marja' at their head, emerged from their wait-and-see attitude and threw themselves into this worldly battle. In Iran, they had until then opted for a policy of accommodation with the Shah, whereas in Iraq they had remained silent in the mid-1920s, except for Mahdi al-Khalisi. 4 Borujerdi (1875-1961) reorganised the hozeh of Qom and attempted to consolidate the religious institutions, which he did so well that the number of students increased again. 5 Muhsin al-Hakim (deceased in 1970) pursued the same objectives in Najaf and gave an impulse to the creation of the Association of Ulemas in 1960 which brought together clerics from different generations and nationalities 6 . However, the two grand marja' were soon overtaken by young, more active clerics less timid to participate in politics, with whom they had an ambiguous relationship. In Qom there was Ruhollah Khomeini, and later his disciple Mortaza Motahhari and in Najaf Muhammad Baqir al-Sadr, surrounded by some others. 7 They became the pillars and ideologues of the 2 Abdul-Hadi Hairi, Shi'ism and Constitutionalism in Iran; Vanessa Martin, Islam and Modernism: The Iranian Revolution of 1906. 3 Sylvia Naef, 'Shi'i-shuyu'i or: How to become a Communist in a Holy City '. 4 For his biography in French, see Pierre-Jean Luizard, La vie de l'ayatollah Mahdi al-Khalisi.

5

Vanessa Martin, Creating an Islamic State, pp. 50-56. 6 Cf. Faleh Abdul-Jabar, The Shi'ite movement in Iraq, pp. 110-113. 7 Such as Muhammad Bahr al-'Ulum, Murtada al-'Askari, Muhammad Baqir al-Hakim, who later founded SCIRII, Muhammad al-Sadr (father of Muqtada) and two Lebanese, Muhammad Husayn Fadlallah and Muhammad Mahdi Shams al-Din. engaged in the reform of Islamic jurisdiction, more specifically the usul, in order to make it more accessible to his students. His publications on the matter are today widely used manuals. 8 He is moreover known for two books that aim at countering Western philosophy and Marxism and thus introduced these subjects in the domain of the hawza; "Our Philosophy" and "Our Economy" 9 became important reference works in Islamic circles. However, he was not the only one to try and lay the foundation of an Islamic economy as a third way next to socialism and capitalism. As far back as the 1940s, Sayyid Qutb had dealt with the question of social justice in Islam, and on the Shia side Mahmud Taleqani had studied the issue of property. But thanks to his knowledge of Marxist terminology, Muhammad Baqir al-Sadr initiated a new way of dealing with Western materialism, which he held had to be better known so as to be more efficiently refuted. His influence in this matter first spread to his close Faleh Abdul-Jabar, The Shi'ite movement in Iraq, pp. 296-305, gives an overview of the theory of Muhammad Baqir al-Sadr on redistribution. See also Houchang E. Chehabi, Distant Relations, p. 148. 11 See Muhammad Beheshti, al-Iqtisad al-Islami and Sira wa Hayat, p. 36-37. Mohammad Beheshti, a The doctrines of Ruhollah Khomeini are another element of these foundations. He partly fits into the tradition of Islamic utopias which also includes Farabi, Ibn 'Arabi and Molla Sadra Shirazi, who themselves were inspired by the concept of the virtuous wise man who governs the polis in Plato's Republic. Indeed, Khomeini was not only the Islamic law expert and politician for which he became famous, he was also a gnostic, a fact which is reflected in his writings on Islamic government. 14 He taught mystic philosophy ('erfan) in Qom from 1940 onwards, at a time when this was frowned upon in clerical circles. Today he is credited for the reintroduction of this discipline in the hozeh. The principal contribution of Khomeini therefore lies in the way he combined mystical philosophy, feqh and political vision, which inspired his theories of Islamic government and velayat-e faqih. He propagated these theories during his exile in Najaf, conferring the powers of the hidden Imam on the theologian-jurist, thus elevating him to the position of guide of the community on the spiritual but also on the political level. This theory, in an adapted version, would later form the basis for the Islamic regime of Iran -as well as a subject of debate among the ulemas.

12 Terms used by Faleh Abdul-Jabar in The Shi'ite movement in Iraq, p. 281, in his presentation of the political theory of Muhammad Baqir al-Sadr. See also pp. 280-287. The Iranian philosopher Mohsen Kadivar, in his study of theories on the state in Shia jurisdisction, classifies the ideas of Sadr under the theories of the elected (intikhabi) Islamic state. Muhsin Kadivar, Nazariyyat aldawla, p. 185. 13 Faleh Abdul-Jabar, The Shi'ite movement in Iraq, p. 114 and following.

14 Vanessa Martin, Islam and Modernism, pp. 31-47. For the gnostic aspects of Khomeini's ideas, see also Yahya Cristian Bonaud, L'imam Khomeiny.

While Khomeini was a mystic theorist who would turn into a pragmatic politician when he came to power, his disciple Motahhari was the real ideologue of the Islamic regime, which would honour him with the title 'Teacher of the Revolution' (mo'allem-e enqelab) and annually commemorate his assassination. 15 Motahhari developed the thought system which the regime drew on to define, organise and mobilise society. He was a theosophist like his master and shared with him a certain vision of the world. However, he was more interested in social issues and was more of a reformist cleric than a revolutionary militant. He vilified the conservative clerics, specifically for their reluctance to engage in politics, and had the ambition to modernise the religious institutions. 16 In his readiness to change society in order to make it more just, Motahhari entered into competition with those in 1970s Iran who were influenced by leninism and anti-colonialism -that is the ideas imported from the West which Motahhari wanted to ban. He therefore engaged in a systematic criticism of Marxism, although only after studying it attentively with all means available to him, and of the Islamic socialism of Shari'ati, which he vehemently resisted. Any movement of secularisation, as well as any attempt to integrate foreign concepts into Islamic doctrines, was in his eyes a conspiracy against Islam. His ideology, like Muhammad Baqir al-Sadr's, aimed to be an alternative and a barrier to the influence of Western materialist thought. Nevertheless, and again like al-Sadr and other Islamic thinkers, Motahhari ended up constructing a hybrid system influenced by the ideas which he opposed. He was a prolific author who left many varied and often reprinted works. 17 construct, aim in the first place at rejecting the process of secularisation affecting Islamic societies, as well as the Western influence which is perceived as an effect of imperialism. Thus they devote major efforts to the modernisation of their institutions (marjayat and hozeh) and struggle to overcome the inertia of clerical milieus. They fulminate against materialist philosophies, countering them with Shia messianism and a mixture of rationalist, reformist, modernist and even mystical theories, reconsidered in the light of anti-colonial ideals. For them, Islam should be turned into an allencompassing system which can respond to all social problems. The quietist attitude, the taqiyya of old, should be rejected and replaced by activism rather than a mere passive awaiting of the return of the Mahdi.

These imperatives were taken from the Qur'an. The fight between good and evil, between the oppressed and the oppressor, was thus described in terms which opposed the downtrodden (mustad'afun) 18 to the arrogant of this world (mustakbarun). The masses are mobilised during religious celebrations, particularly Ashura, with slogans that are chanted every year again without losing their evocative power. Thus, during the celebrations following the July war against Israel, the Lebanese Hezbollah proclaimed 'the victory of the oppressed' (intisar al-mazlum), referring to the paradigm of Husayn, the martyr of Karbala. In doing this, the party gave a new sense to the paradigm, since it was no longer a symbolic or moral but a real victory they claimed.

While the concepts of traditional Shi'ism underwent an ideological reinterpretation, the organisational methods characteristic of leninist parties, such as a pyramidal structure and a cult of secrecy, were freely borrowed to enhance the efficiency of activism. Yet both the concepts which were developed and the forms and methods of mobilisation used always had as their aim to produce and promote an ideology upholding Islamic modernity. Since the end of the nineteenth century, Islamic societies -and their clerics -have in effect been confronted with a modernity imposed by a conquering and hegemonic West, and have been searching for an appropriate response. 19 The "revolutionary" Shia movements, with Iran at their head since 1979, have been offering their versions too.

18

In Lebanon, Musa al-Sadr used the term mahrum, traditionally translated as 'disinherited': he was the initiator of the Harakat al-mahrumin, the Movement of the Disinherited.

19

The representations in the media of a 'retrograde' or 'medieval' Iranian regime have wiped out the notion that the regime resulted from a rupture with the classic doctrines and an attempt to construct an endogenous modernity. On this point see the chapter "The Modernity of Theocracy" in Juan Cole's Sacred Space and Holy War.

Nevertheless a more discrete current that predates the revolution has been making its way and offering alternative answers, unfolding a vision of an Islam more humanist than political, and without the wholesale rejection of either the ideas imported from Europe or the secularisation affecting Muslim societies. Two different types of actors, clerics and religious intellectuals, were the carriers of this movement, which is often qualified as reformist. We must here again note the difficulty we mentioned earlier of classifying people and their ideas. The clerics involved in this movement became better informed about worldly affairs and an elite among them was well-versed in the profane sciences as well as Christian theology. We can mention here, as an example, Mohammad Mojtahed Shabestari, who directed the Islamic Centre in Hamburg, founded on the initiative of Borujerdi in 1969. "Doctor ayatollah Beheshti" was his predecessor in this position and Mohammad Khatami his successor. 20 Shabestari stayed in Hamburg for almost a decade, studying Christian philosophy and theology before returning to Tehran just before the Revolution, by which time he spoke Arabic, English and German. 21 In a parallel movement intellectuals, most of them with university degrees in various specialisations, studied the religious sciences, following the example of Soroush. And like academics taught at the hozeh, especially in reformed schools, religious clerics offered courses at universities, mostly in the philosophy departments (as for example Shabestari and Kadivar). Some of them, like Malekian, even though they were integrated in the system of the hozeh, never wore the turban.

While this phenomenon can today be observed throughout the hala islamiyya, notably in Iraq and Lebanon, it is still less common there than in Iran, where it was generalised by the 'cultural revolution' (enqelab-e farhangi). In 1980, after the closure of the universities, Khomeini put in place several organs charged with integrating the hozeh and the universities, bringing together intellectuals and men of religion. After months of discussing and introducing certain 'islamised' subjects in their curriculums, certain university functionaries participating in the reform project considered that they could not go any further. 22 Others, on the contrary, especially 20 In the 1960s Beheshti, who read German and English, was an exception. The large majority of clerics hadn't completed their secondary education. Yann Richard, 'Le rôle du clergé', p. 14. Note that his companion Musa al-Sadr, who established himself in Lebanon, had also enjoyed a double education.

21 Katajun Amirpur, 'Mohammad Mojtahed Shabestari'; Muhammad Rida Wasifi, al-Fikr al-islami, p. 315. 22 Interview with Gholamabbas Tavasoli, university of Teheran, 07/04/2004. clerics, wanted to proceed towards a complete islamisation of the social sciences and establish a system of lasting cross-overs connecting the university and the hozeh, and they continued their efforts in this direction with the support of the government. Sheikh Mohammad Taqi Mesbah Yazdi, for example, organised exchanges within the framework of the Hozeh o daneshgah (hozeh and university) Committee, sponsoring the initiation of about a hundred academics in the Islamic sciences with the objective of bringing them to criticise the social sciences from an Islamic perspective. Upon their return to the university, they were meant to become the pillars of the cultural revolution. This particular project was never brought to an end, but the radical sheikh continued to push for co-operation between the two institutions and the adoption of an Islamic point of view in the social sciences, both in his writings and in the educational institution in Qom which he directed. 23 The activities of the Hozeh o daneshgah Committee have become more important over the last ten years, especially through the publication of books aiming to islamicise the social sciences. 24 The Iranian experience in the matter is often considered a model, as in Lebanon where the hawza milieus wish to establish links with the universities in order to obtain equivalent diplomas for their students. Nevertheless, the same experience is also criticised, both inside and outside Iran, and not only by intellectuals but by reformist clerics. Schematically speaking, the matter comes down to the question whether one wants to islamicise modernity or modernise Islam. The proponents of the latter option tend to draw upon the social sciences, accepted as universal, in order to develop their comprehension of the doctrines.

A New Theology

In reformist circles in the Persian and Arabic worlds, scholars talk about a new or modern theology ('ilm al-kalam al-jadid), which is to be distinguished from the ancient science of kalam in both its methods and its object. New questions are addressed that are treated in the classic kalam, and the tools used in this effort transcend the Islamic sciences to incorporate human sciences as they are practised today. Furthermore, this new theology does not aim to defend religion but rather to 23 Interview with Mohammad Taqi Mesbah Yazdi, Qom, 19/08/2003. An illustration of his method can be found in his work Usul al-ma'rif al-insaniyya, that presents in Arabic the lectures he has given in Beirut.

24

Interview with Sayyed 'Arabi, Qom, 01/01/2004. Information can be found on the website of this institution, which later became a research centre affiliated to the hozeh of Qom in 1990: <http://www.hawzeh.ac.ir>. understand it. In Iran, the cleric best representing this current, having become the main name in the field, is Mohammad Mojtahed Shabestari. For some, he has become a model, others have attacked him, but like Soroush he became part of the cognitive landscape and those who are interested in the subject cannot ignore him. He has written relatively little as he prefers to concentrate on teaching and on his research for an Islamic encyclopaedia 25 , but he has marked an entire generation. His status as a cleric and his education at the hozeh of Qom, where he studied from 1950 until 1968, also give him credibility in religious circles. He was close to Beheshti and part of the editorial board of Maktab-e eslam, a journal on social and political issues. Shabestari also has substantial knowledge of Catholic and Protestant theological matters, acquired during his decade-long stay in Hamburg. He is both mojtahed and doctor in philosophy and the influence he exerts clearly shows this fact.

Shabestari bases himself on the writings of "Allama" Tabataba'i (d. 1981), meaning he refers to the Islamic philosophical tradition in its most contemporary forms. Tabataba'i was not only a famous exegete but also popularised the ideas of Molla Sadra Shirazi, which he introduced to the hozeh, teaching from the Book of Four Journeys. 26 For Shabestari, the spiritual journey does not lead to the annihilation in God, as is the case for the ideologues Motahhari, Khomeini and even Shari'ati, but to the consciousness of the self and the affirmation of man and his freedom. That is to say he has a different approach to the 'erfan, which he does not associate with Islam as an all-encompassing system capable of providing the answer to all the problems posed by modernity. 27 Moreover, when Shabestari takes up his metaphysical hypotheses he notes the incapability of classic philosophies, such as the feqh, to renew its comprehension of the world. It is therefore necessary to draw on modern sciences to build up those sciences that are missing in Islam, like the philosophy of law, morality, politics and economics. 28 The contribution of Shabestari lies in his demonstration of the fact that religious knowledge, even though it is declared to be eternal, is limited and changing, and this is what he has in common with Soroush. It is therefore the task of thinkers to adapt to the age and develop an adequate approach and a critical apparatus, which is 25 Da'erat-e bozorg-e eslami, in Teheran. something he applied himself to in his Hermeneutics of the Qur'an and the Sunna (1996), one of his main works, together with his work on freedom and faith and his Religion (2000). Mojtahed Shabestari also took part in the public debate in Iran by writing articles for different journals.

Critique of the Official Reading of

The ideas of Shabestari and other Iranian thinkers travelled beyond the Iranian borders. In 1995, the journal al-Muntalaq published an interview with him in which he announced with pride, after explaining that this new theology was still in its infancy, the existence of a "nucleus" and expressed his hope to see an increase in contributions and debates. 29 Al-Muntalaq is the archetypal magazine of the Lebanese Islamic sphere, whose history has partly been written in its own pages over the years.

It was created in Beirut in September 1977 by the Lebanese Union of Muslim

Students, an organisation sponsored by Muhammad Husayn Fadlallah, who made the magazine his forum in the 1980s. 30 It subsequently opened its pages to the debates taking place within the Shia movement of Lebanon. From the second half of the 1990s onwards, its editor-in-chief Hasan Jabir used it to spread the ideas of Iranian thinkers. In 1998 he published a special issue on 'the renewal of theology', with four articles translated from Persian offering different perspectives on the matter. 31 For several years, a kind of euphoria reigned: this new approach opened fields which hadn't received attention in classic Shiism and allowed the discussion of issues grounded in reality and experience, including the experience of Islamic government in Iran and its limits. "Before, we would think about the relations between God and his servant, now we think about the problems of man in society, and about politics (shura and democracy), and this implies an accommodation and renewal in all religious sciences." 32 Hasan Jabir himself prefers to reflect on the philosophy of fiqh and is interested in the values underlying the norms. 33 Today he continues in this direction and, as a university graduate, has started to teach the new theology in a hawza. 34 Enthusiasm for the new theology quickly spread; 35 in Qom, it reached the circles of non-Iranian students and teachers at the hozeh who had access to the Persian texts.

Iraqi, Lebanese and Gulf Shia joined in informal discussion circles. In 1994 one of 29 Hasan Jabir, 'al-Tajdid wa al-taqlid', p. 46. 30 Jamal Sankari, Fadlallah. The making of a Radical.

31 Al-Muntalaq, nr 119, Autumn-Winter 1997-1998. 32 Interview with Hasan Jabir, Beirut, 28/12/2001. 33 Hasan Jabir, al-Maqasid al-kulliyya. 34 Interview in Beirut, 13/04/2003. 35 Interview with 'Abd al-Jabbar al- Rifa'i, Qom, 28/08/2003. them, 'Abd al-Jabbar Rifa'i, founded a journal that would form a true bridge between the intellectual fields of Iran and the Arab world and, even more, a transnational forum for Shia and Sunni thinkers: Qadaya islamiyya mu'asira (Contemporary Islamic Issues). 36 'Abd al-Jabbar Rifa'i was a prolific writer, and his intellectual trajectory deserves a closer look. He was born in a peasant family in a village close to Nasiriyyah and attended the primary school which was opened there after the revolution of 1958. Then he started a journey that brought him first to Baghdad, where he completed a course in agronomy, and then to the hawza of Najaf, where he studied from 1978 till 1980. The regime's repression forced him to leave Iraq and in 1984 he arrived in Qom. He describes himself as always 'in search of science' and to this day teaches at the hozeh and the university. Although he does not wear the turban, he is a 'sheikh'. He received a classic education and tried out all the possibilities offered by the freedom of choice that characterises education at the hozeh, before formulating his critique of the system in order to "modernise it and open it to the century".

Qadaya... and her sisters

His project entailed a real reconstruction of the religious sciences and the representation of the divine, and this was the topic of his journal, which also gave a platform to a group of students and clerics at the hozeh who, as Rifa'i puts it, "had no voice before". 37 Virtually without assistance, 'Abd al-Jabbar al-Rifa'i published in Arabic not only philosophers like Shayegan and reformist thinkers like Soroush, Shabestari or Malekian, but also authors that opposed their ideas.

"Qadaya did not try to establish a certain position as the right line, but to expose the reader to various opinions," Rifa'i explained. "What is important is opening breaches to trigger reflection, and this can only be done by raising questions, because the history of thought is the history of raising important questions." 38 The articles published therefore sometimes sharply contrast with each other, although -as is common in this type of publications -the tone and certain formulations soften the discourse. Some ulemas of Qom have written in Qadaya, such 36

The journal first carried the name Qadaya islamiyya, under which the first five issues were published from 1994 till 1998. Apart from authors' texts and interviews translated from Persian to Arabic, Qadaya also offers reports on the debates and round tables which it organises itself or takes over from Persian journals such as Naqd o nazar, which is connected to the hozeh of Qom. Its publisher grasps every opportunity to bring thinkers together and record their exchanges. The themes Qadaya Islamiyya mu'asira has broached since 1998 are a good illustration of the evolution of the questions that are debated today. There are special issues on Shia political thought (nrs. 1 and 2, 1998), contemporary Islamic thought and its new orientations (nr. 5, 1999), Qur'anic exegesis (nr. 4, 1998), which includes the translation of Shabestari's work on hermeneutics (nr. 6, 1999), the philosophy of Islamic jurisdiction and a new interpretation of the approach of the maqasid (nrs. 7 and 8, 1999; nr. 13, 2000), the doctrine of Muhammad Baqir al-Sadr (nrs. 11 and 12, 2000), the new theology (nr. 14, 2001), liberalism (nr. 24-25, 2003), tolerance (nrs. 27 and 28-29, 2004), 'living together' and religious and cultural pluralism (nr. 31-32, 2006). The latter issue publishes authors representing various currents, including Daryush Shayegan, Mojtahed Shabestari and a debate between John Hick and Hossein Nasr in Istanbul. The table of contents shows that the journal is sensitive to the questions raised by the current political situation in the region, notably in Iraq, where the editor has tried to re-establish himself after 2003, which explains the irregularity of its publication. dozen of books on contemporary Shia thought. 44 He is one of the new, 'islamoliberal' reformists 45 who, after returning to Saudi Arabia and rejecting their revolutionary ideals, want to make their voices heard in a dialogue with the political constituents of the country. Two other journals of a similar type are published at educational institutions. Al-Hayat al-tayyiba is published by the hawza Ma'had Rasul al-Akram, which we will meet again later in this essay, and whose chief editor is the hawza's former director, the Iranian cleric Najafali Mirza'i. The journal, created in 1998, mainly focuses on the modernisation of religious education and has gradually become an eclectic debating forum, as much because of the choice of authors as through the selection of themes. This pluralism is also reflected in the composition of its editing board 46 and shows that there is room for manoeuvre even for institutions See Stéphane Lacroix, 'Between Islamist and Liberals', pp. 12-13. 46 Including clerics who are known as broad-minded, such as Muhammad Hasan al-Amin and the "neo-conservative" Mohammad Taqi Mesbah Yazdi, clerics and intellectuals, Shia and Sunnis (for example Ridwan al-Sayyid, founder of the journal al-Ijtihad, and today leading the journal al-Tasamuh). plurality of interpretations, etc." To this purpose, it affirms its willingness to "benefit from the contemporary intellectual experience of the Iranian cultural arena" and offers texts of interest to the Islamic sphere in Arabic translation. Its objectives are clearly stated in the well-made electronic version of the journal. 47 It offers the same type of debates as published in Qadaya, bringing for example a new translation of Qazb va bast by Soroush. It justifies this by arguing that the previous translation was marred by omissions and lack of precision and that the the text and the polemics it incited are too important not to remedy this situation. 48 As for reformist options, although Nusus mu'asira offers more conservative analyses, its articles do often deal with reform (islah) and renewal (tajdid), like the other journals. Not all authors attach the same importance to these notions, depending on their point of view, but the aim remains to find modalities to accommodate Islamic thought in the modern world, whether or not in articulation with a political vision of Islam. Meanwhile we should not forget that these journals only interest a small elite. Najafali Mirza'i, the Iranian cultural consul, estimates that "some journals sell five hundred copies per issue; their readership is very limited in Lebanon although it is larger in Morocco and Egypt.' 49 Qadaya islamiyya mu'asira has the largest readership as it is the oldest journal and definitely the one most in touch with the reformist debates.

A Predilection for Philosophy

If we have to draw a distinction between Arab and Persian Shi'ism, the predilection of the latter for mysticism, gnosis ('erfan) and philosophy must definitely be mentioned. This was also the view of Henry Corbin, who describes the phenomenon very well. 50 We find in Persia mystic orders that are absent in Arab Shi'ism and theosophists unparalleled there. Although the hawza of Najaf has also started teaching philosophy again, to Qom philosophy is one of its specific characteristics, and it is in the field of philosophy that the opposing camps of conservative supporters of the regime and reformists paradoxically meet each other, even if they do not understand the subject in the same manner. For the former, gnosis and philosophy serve a worldview that proposes an all-encompassing Islam, an Islamic utopia, while for the latter, the same 47 <www.nosos.net>. See notably 'Li-madha nusus mu'asira?' (Why Nusus mu'asira), by Haydar Hubb Allah, chief editor of the journal.

48

Cf. Nusus mu 'asira, 5, Winter 2006, p. 136. 49 Interview at the Iranian Cultural Centre in Beirut (Bir Hasan), 21/12/2006.

  companions and his contemporaries, starting with his cousin Musa al-Sadr, who wrote articles on economy in the journal Maktab-e eslam, published in Qom, focusing on the question of redistribution, a subject given much attention by Muhammad Baqir. 10 Note that Musa al-Sadr was equally in contact with Mohammad Beheshti, who also published on Islamic economy and particularly on the banking system. 11 On the political level, Muhammad Baqir al-Sadr developed an original conception of the Islamic state, a conception which evolved significantly between the 1960s and the late 1970s. His theory is different from Khomeini's and advocates militantism and the institutionalisation of the clergy, but also the separation of powers which he divides between the nation and the clergy, with both remaining subjected to the constitution and the law. It can thus be considered a "liberal hierocracy"or a "semi-8 Notably al-Ma'alim al-jadida, a very clear introduction to the usul, and Durus fi 'ilm al-usul, a more difficult work translated into English by Roy Mottahedeh. Cf. Muhammad Baqir as-Sadr, Lessons in Islamic Jurisprudence. 9 Falsafatuna (1959) and Iqtisaduna (1961) are regularly reprinted in Arabic and at least partially translated by Islamic publishers. About these works, see Chibli Mallat, The Renewal of Islamic Law; and John J. Donohue, 'Notre économie'.10

  student of Khomeini, later played a major role in the establishment of the Islamic Republic. He died in a bomb explosion at the headquarters of the Party of the Islamic Republic in Tehran in June 1981. Jean-Pierre Digard, Bernard Hourcade and Yann Richard, L'Iran au XXe siècle, p. 184. liberal populist system". 12 Muhammad Baqir al-Sadr, who was a prolific author, also published a journal, al-Adwa' (the Lights) in close collaboration with the young Lebanese clerics Muhammad Husayn Fadlallah and Muhammad Mahdi Shams al-Din. 13 He furthermore played a role in the Islamic movement, as he inspired the al-Da'wa party, although up to the present moment little is known about his exact relationship to the party. Shortly after the Iranian revolution, Muhammad Baqir al-Sadr had become too dangerous in the eyes of the baathist regime. He was executed in April 1980 and members of al-Da'wa were prosecuted. This caused them to disperse geographically and diverge in their political choices, leading to a ramification of the party into different branches. Nevertheless, the experience of al-Da'wa and the ideas of Muhammad Baqir al-Sadr constitute the basis of the current movement, especially for the Arab Shia. Almost every party refers to him in some fashion or another.

  Today, Muhammad Baqir al-Sadr and Mortaza Motahhari are often named by actors in the Islamic sphere as the founding fathers of Shia Islamic ideology although other authors have adopted and adapted their ideas and developed and refined them in order to create their own movements. What is particular to Shiism is that its ideologues, with the exception of some Iranian "religious intellectuals" such as Shari'ati, are all high-ranking clerics in the religious hierarchy. The ideologies they 15 Amir Nikpey, Politique et religion en Iran, p. 221. Motahhari was killed in May 1979 by a member of the Forqan group. 16 About his reform programme for the clerical institutions, cf. Linda Walbridge, The most Learned of the Shi'a, pp. 161-182, which includes Motahhari's text 'The fundamental problem in the Clerical Establishment', with an introduction by Hamid Dabashi. 17 Vanessa Martin, Creating an Islamic State, chapter IV: 'Motahhari: Towards an Islamic Ideology and the Battle for Control of Political Islam'; Amir Nikpey, Politique et religion en Iran, pp. 218-230. About the attacks against Shari'ati, see Ali Rahnema, An Islamic Utopian, chapter XVI and XVII.

  26Cf. Hamid Dabashi, Theology of Discontent, chapter V and Lloyd Ridgeon, Religion and Politics, chapter VIII. 27Farzin Vahdat, 'Post-revolutionary Discourse', pp. 41-43. 28 Id. p. 39 and Mahmood Sadri, 'Sacral Defense of Secularism', p. 261.

37

  Interview with 'Abd al-Jabbar al-Rifa'i, Qom, 28/08/2003. 38 Interview with 'Abd al-Jabbar al-Rifa'i published in the newspaper al-Ayam (Bahrain), 26/01/2004, available on <www.islamonline.net/Arabic/arts/2004/01/article17.shtml>.as Mohammad Taqi Mesbah Yazdi, Ja'far Sobhani and Naser Makarem Shirazi.Lebanese reformists including Muhammad MahdiShams al-Din, Muhammad Husayn Fadlallah, Muhammad Hasan al-Amin or Hani Fahs have encouraged the publisher of Qadaya, which is printed in Beirut and distributed throughout the Arab world, especially in Egypt and Morocco, where it has found an audience. It also publishes texts by the Egyptian Hasan Hanafi, "discussing ideology rather than epistemology" 39 and by Maghrebi authors. 'Abd al-Jabbar al-Rifa'i states that the thinkers from the Maghreb, contrary to the Iranians, are outside of the Islamic sphere, but stresses the closeness of their thought, mentioning Mohammed Talbi, 'Abd al-Majid Chafri, Abdou Filali-Ansary,... and most of all Mohammed Arkoun, whom he considers the most remarkable among them.

  Although he lives in Qom most of the time, 'Abd al-Jabbar al-Rifa'i has founded a centre in Baghdad, the Centre for the Study of the Philosophy of Religion and the 39 In the words of 'Abd al-Jabbar al-Rifa'i. New Theology, which co-publishes books about scientific approaches to Islam, such as a collective volume on the anthropology of Islam 40 and a work by 'Abd al-Jabbar al-Rifa'i, in which he exposes in a very didactic way what modern theology is and which important questions it has dealt with with since the tiùe of Jamal al-Din al-Afghani. 41 Its journal is moreover reprinted in Damascus and Beirut in the form of volumes that form several series. 42 We will take a closer look at two of these publications which directly concern new theology. The first, Theological Ijtihad, contains several interviews with the Egyptians Hasan Hanafi and Muhammad Imara and the Iranians Mojtahed Shabestari, Mostafa Malekian and Ahad Qaramelki, as well as Sadeq Larijani, renowned for offering the best critique of Soroush from the conservative side, explaining his position on the issue. The second, New Theology and the Philosophy of Religions, contains interviews with several of the same authors as well as others, and includes moreover the texts of a round table on religious rationality and theology attended by Iranian clerics and philosophers. 43 We observe both a variety of perspectives and opinions and a diversity of authors, offering a glimpse on the richness of the Iranian intellectual arena. The journal Qadaya islamiyya mu'asira has contributed a wealth of reflections on the modernisation of Islam by giving a voice to authors ranging from the most reformist to the most conservative. It brings together actors from the hozeh and from the university, including Shia from Iran, Lebanon, Iraq and the Gulf as well as Sunnis, in particular the leading figures of various magazines published in Beirut and of the Prologues in Casablanca. This small world can gather and debate the issues during the pilgrimage to Mecca as well as at a conference in Rabat. Qadaya islamiyya is today the best known journal in its field and the most widely distributed, but it is not the only one published in Shia circles who consider themselves enlightened. In Damascus a disciple of Rifa'i publishes al-Wa'i al-mu'asir (Modern Consciousness). In Beirut, al-Muntalaq al-jadid succeeds al-Muntalaq and continues in the same current under the direction of a woman, Zaynab Shurba. Al-Kalima (The Word) is published since the 1990s by a Saudi Shia cleric, Zaki al-Milad, author of a 40 Abu Bakr A. Baqadir, Anthrubulujiya al-islam. This volume contains Arabic translations of articles of Jacques Waardenburg, Eric Wolf and Cliford Geertz. 41 Abd al-Jabbar Rifa'i, Muqaddima fi al-su'al, 2005 42 In Damascus, the books are published by Dar al-Fikr and in Beirut by Dar al-Hadi and Dar al-Fikr al-Mu'asir.

  that depend on the Iranian clerical establishment: the journal and the hawza are both financed by the organ which co-ordinates Iranian schools abroad. It also confirms the importance of the individual in relation to the institution; in this case, because it is the chief editor who sets the tone. Al-Mahajja is a journal published by an institute that offers courses in Islamic philosophy in the southern suburbs of Beirut. Its focus is therefore on philosophical questions but in many ways it also resembles the other journals mentioned, often publishing the same authors and sometimes even the same articles. The particularity of al-Mahajja lies in the fact that it also publishes articles by Christian theologians and Lebanese authors such as philosopher and theologian Paul Khoury, who are in touch with the institute, whose director is also editor-in-chief of the journal. More recently, Nusus mu'asira (Contemporary Texts) was established; its offices are in Beirut but those in charge of it reside more often in Qom or in the Gulf, which is hardly surprising, as one of them teaches in Qom while the direction is in the hands of 'Abd al-Hadi al-Fadili, a Saudi cleric and former companion of Muhammad Baqir al-Sadr in Najaf, who returned to Saudi Arabia a few years ago. Published by the Centre for Contemporary Research (Markaz al-buhuth al-mu'asira), the journal claims to specialise in "the translation of texts that deal with women's issues, modernity, dialogue, openness towards the other, philosophy of fiqh, modern theology, the 44 Zaki Al-Milad, al-Fikr al-islami.

  45

Abd al-JabbarRifa'i, 'Ilm al-kalam and al-Ijtihad al-kalami.

Henry Corbin, En islam iranien.

elements instead are the vectors for the individualisation of religion.

In Lebanon, a generation of clerics trained after the revolution have returned imbued with a knowledge that was not shared by their elders, who were moulded by the ideas current in 1960s Najaf. They transmitted these ideas in their turn to others. Thus, in 1999 sheikh Shafiq Jaradeh founded the institute of theosophy for religious and philosophical studies (Ma'had al-ma'arif al-hikmiyya li-l-dirasat al-diniyya wa alfalsafiyya) in the southern suburbs of Beirut. The evening courses there are organised in two sections: one is reserved for enrolled students who are required to succeed in a certain number of philosophy courses -'irfan, fundamental beliefs ('aqida), theology, morality, etc. -to obtain their degree, which is not recognised by the state. The other, open to all, offers courses of methodology, sufism and 'irfan. The aim is not so much to educate specialists but to 'broaden the cultural horizon' of hawza or university students in these disciplines and guide their researches by offering them a method.

The registration fee is relatively modest, aiming mostly to shift out non-serious applicants, since the institute is financially supported by the 'marja'iyya khums', that is by 'Ali Khamenei. Shafiq Jaradeh originally started out by teaching a classic work of 'irfan 51 , as well as the work of 'Allama Tabataba'i, who is considered the founding father of the philosophical milieu in Qom. 52 Later he widened his interest, notably including the history of philosophy and Christian theology. "John Hick has influenced Iranian thought and I think he should be read like other Christian theologians, to benefit from their experience," he declares. Moreover, Muslims and Christians regularly gather at the institute for debates where all share their views on issues faced by all religions. Thus, the institute maintains a permanent dialogue with Paul Khoury, "who plays the role of John Hick in Lebanon", Bishop Georges Khodr and father Mouchir Aoun, from the Université du Saint-Esprit in Kaslik. 53 "If we don't discuss the questions that affect us in a religious framework transcending Islam, we will not develop", considers Shafiq Jaradeh. "And if God is for all of us, how can I monopolise Him? We need to have a dialogue and consider the points on which we 51 Mahdi Bahr al-'Ulum, al-Sayr wa al-suluk. This is a treaty of practical gnosis, describing methods for the adoration of God (dhikr, contemplation, etc.).

52

Abd al-Jabbar Rifa'i, Tatawwur al-dars al-falsafi, chapter IV. 53 Paul Khoury is a theologian and philosopher at the Institut Saint-Paul de Philosophie et de Théologie in Harissa. Georges Khodr is the bishop of the Greek Orthodox Church for Mount Lebanon and has been very engaged in the renewal of the Church. Mouchir Aoun teaches philosophy and intercultural dialogue at the faculty of theology at the Université du Saint-Esprit in Kaslik. agree and acknowledge those on which we differ." 54 This discourse resonates with a certain public in the southern suburbs, where the youth is a demanding party for a new approach to Shiism, different from the daily worship with its rules, and sometimes even for spirituality. Philosophy and 'irfan also attract militant students or sympathisers of Hezbollah; they find here an intellectual content to sustain their commitment. Besides, Shafiq Jaradeh is known to be close to the party. Women are also present at the institute and are even in the majority at the Institute of Oriental Philosophy (Ma'had al-ishraq) directed by the cleric Muhammad al-Hajj, a kind of cultural centre also located in the southern suburbs, where people come in the evenings to submerge themselves in metaphysics and theosophy.

The transcendental philosophy of Molla Sadra Shirazi has also made its way into the Lebanese hawza, like other newly formed disciplines aiming at the modernisation of education in the religious sciences. These schools are in fact reformed institutes which do not follow the system of the classic 'free' hawza, where every student can choose his teachers and his courses, instead following the university model. 55 In Lebanon, the most modernist among them are directed by young clerics and placed under the religious authority of either Muhammad Husayn Fadlallah or 'Ali Khamenei. 56 In addition to the secular social sciences (sociology, psychology, pedagogy), new disciplines of the Islamic religious sciences have been introduced.

While it has become common to offer courses in Islamic jurisdiction with a comparative approach between the Shia and Sunni schools, it is a more recent phenomenon to have courses relating Islamic law to positive law. The general subject of fiqh has various branches: its history and practice, its social aspects, the norms (ahkam), the fatwas, etc. are studied in separate courses. The philosophy of fiqh, a discipline that first appeared in the journals, has made its entry in educational programs, as has the new theology. Eventually, the debates between ulemas and religious intellectuals find their practical application in the introduction of new categorisation of the disciplines, a willingness to structure the teaching and an openness to social science literature produced abroad. All of it is presented in a clear and elegant form. The director, well-informed about the issues that occupy the religious circles, explains his objective in the introduction: to modernise the hawza without taking away its depth. 58 We could be tempted to see this as the influence of Iran with its experience in founding and administrating this type of establishment, especially since the school follows the marja'iyya of 'Ali Khamenei. But in fact it should also be seen as the marks of individual initiatives -as always in Shia institutions, who have difficulty to ensure their continuity in its own name, rather than in reference to a founder. The institute has been under the direction of Najafali Mirza'i, a cleric who is very taken by the contemporary debates and editor-in-chief of a journal which publicises them, al-Hayat al-tayyiba. 59 He has since also founded a research institute in Beirut whose efforts are directed towards introducing the Arabic and Iranian civilisations to each other (Markaz al-hadara li-l-dirasat al-iraniyya al-'arabiyya), and which focuses mainly on the different currents in contemporary thinking. 60 The Iranian Fingerprint?

When we ask him whether his taste for philosophy and new theology is an effect of the Iranian influence, Najafali Mirza'i seems to think it is not. "People study Molla Sadra Shirazi because he is a Shia, not because he is Iranian." He goes even further, "Great thinkers are universal. Ibn 'Arabi, for example, wasn't "Sunni and Arabic", he belonged to everybody. 61 The same is true today for Soroush or Shayegan, they are not Iranian thinkers…". To the same question, Muhammad al-Hajj answers rather humourously, "Our association does not follow Iran, it follows the ideas of Shiraz.

Here we are not interested in ideology but in metaphysics." 62 Shafiq Jaradeh declares 57 Dalil Ma'had al-rasul al-akram, 2003-2004, 471 pages. 58 Id., pp. 10-11. 59 Meanwhile he has founded a research centre in Qom and has returned to Lebanon as cultural council.

60

The centre translates books into both languages on subjects ranging from contemporary poetry to the philosophy of fiqh, women's rights and the theoretical foundations of the Islamic Republic. Interview, Beirut, 21/12/2006. 61 Note that Ibn 'Arabi occupies an important position in the theoretical Shia 'erfan because his theories have been adopted by Molla Sadra, which shows the pertinence of the example. that, as the history of philosophy wasn't being taught, he tried to teach it the "Iranian way", although adding Arabic authors.

Concerning the "new theology", if we are to believe some, it is not that new. Its critics consider, albeit slightly in bad faith, that it is an ancient discipline in a new jacket and that only the formulation has changed. Its proponents, for their part, write its history. Abd al-Jabbar Rifa'i traces its origin back to the Indian scholar Shibli No'mani (d. 1914), author of a work entitled The New Theology. He further mentions the famous Egyptian reformist Muhammad 'Abduh (d. 1905) and his Risalat altawhid (Treaty of Oneness) and finally Mohammad Iqbal (d. 1938) who, more than the above-mentioned, truly nourished the project of the reconstruction of religious sciences in Islam. 63 The next step is constituted by the writings of Mohammad Hossein Tabataba'i, his disciple Mortaza Motahhari and Muhammad Baqir al-Sadr. 64 After that, the force of Iran lay, for him, in the production of intellectuals who were not only trained in the classic system of the hozeh, but also enjoyed a modern, scientific academic education. 65 They were therefore able to think about Islam with the intellectual tools of their time. A large number of proponents of the new theology draw a parallel between the openness of contemporary thinkers towards western social sciences and the movement of translation of Greek philosophy in the ninth century, which lay at the origin of the development of the falsafa. "However", adds Mohammad Mojtahed Shabestari, "in the time of Ma'mun, Muslims dominated the world and translated, while now they borrow ideas that they think are universal."

Modern Islamic theology may be the outcome of a historical process, but it is not limited to Iran. The existence of the Islamic Republic certainly raised questions that encouraged its development but, according to Shabestari, it is also developed elsewhere in the Muslim world. The writings of the Egyptian Nasr Abu Zayd, for example, or the Syrian Muhammad Shahrur, even if they are part of Qur'anic studied by Arab authors before Soroush, "his reading was therefore a shock for the Iranians but not for us", he states. 67 If some years ago, one could hear in the "Islamic sphere" remarks such as "we do as in Qom" or "this comes from Iran", this is no longer so prevalent today. More than a merely political reason, we should see in this the effect of a habit and an expression of attachment to Arabic culture. Furthermore, the reformist thinkers who claim to be open towards the world, are also open towards the Islamic worlds and are consciously attempting to transcend identity constructions of 'belonging' and take only intellectual affinities into consideration. Finally, let us not forget the personalities on the local religious and intellectual scenes, who do not refer to Iran and do not consider themselves influenced by its thinkers, even if they read them. This holds true for the Lebanese Muhammad Husayn Fadlallah, who follows his own road as marja' and applies a reformism that is more practical than theoretical, as well as for another Lebanese, Muhammad Hasan al-Amin, who is rooted in his society and in the local Arabic Shiism. [START_REF] Muhammad | [END_REF]


I Guénot-Delahaie
email: isabelle.guenot-delahaie@cea.fr

J Sercombe

T Helfer

P Goldbronn

É Fédérici

T Le Jolu

A Parrot

C Delafoy

C Bernaudat

SIMULATION OF RIA TRANSIENTS ON UO 2 -M5® FUEL RODS WITH ALCYONE V1.4 FUEL PERFORMANCE CODE

Keywords: PWR, nuclear fuel, UO 2, M5®, RIA, ALCYONE code

The ALCYONE multidimensional fuel performance code co-developed by the CEA, EDF and AREVA NP within the PLEIADES software environment models the behavior of fuel rods during irradiation in commercial Pressurized Water Reactors (PWRs), power ramps in experimental reactors or accidental conditions such as Loss Of Coolant Accidents (LOCAs) or Reactivity-Initiated Accidents (RIAs). As regards the latter case of transient in particular, ALCYONE is intended to predictively simulate the response of a fuel rod by taking account of mechanisms as close to physics as possible, encompassing all possible stages of the transient as well as various fuel/cladding material types and irradiation conditions of interest. On the way to complying with these objectives, its development and validation shall include tests on PWR-UO 2 fuel rods with advanced claddings such as M5® under "low pressure-low temperature" or "high pressure-high temperature" water coolant conditions. This paper first presents the ALCYONE V1.4 RIA-related features and modeling. It especially focuses on recent developments dedicated on the one hand to non steady water heat and mass transport and on the other hand to the modeling of grain boundary cracking-induced fission gas release and swelling. This paper then compares some simulations of RIA transients performed on UO 2 -M5® fuel rods in flowing sodium or stagnant water coolant conditions to the relevant experimental results gained from tests performed in either the French CABRI or the Japanese NSRR nuclear transient reactor facilities. It shows in particular to what extent ALCYONE -starting from base irradiation conditions it itself computes -is currently able to handle both the first stage of the transient, namely the Pellet Cladding Mechanical Interaction (PCMI) phase, and the second stage of the transient, should the boiling crisis occur. Areas of improvement are finally discussed with a view to simulating and analyzing further tests to be performed under prototypical PWR conditions within the CABRI International Program.

M5® is a trademark or a registered trademark of AREVA NP in the USA or other countries.

I. INTRODUCTION

ALCYONE is a multi-dimensional finite element-based nuclear fuel performance code co-developed within the PLEIADES software environment by the CEA, EDF and AREVA NP. Dedicated to pressurized water reactor (PWR) fuel rod behavior, it solves fully-coupled equations of thermo-mechanics and chemical-physics under irradiation for three different schemes: a 1.5D scheme to model the complete fuel rod, a 3D scheme to model the behavior of a pellet fragment with the overlying cladding, a 2D(r,θ) scheme to model the mid-pellet plane of a pellet fragment. [START_REF] Sercombe | 1D and 3D modeling of PCMI during a RIA with ALCYONE V1.1[END_REF] ALCYONE is capable of steady state and transient fuel performance modeling. [START_REF] Michel | Modeling of pellet cladding interaction[END_REF] The simulation of reactivity-initiated accident (RIA) experiments falls in particular within its scope and has been given increasing interest and resources in recent years. [START_REF] Michel | Modeling of pellet cladding interaction[END_REF][START_REF] Sercombe | 2D simulation of hydride blister cracking during a RIA transient with the fuel code ALCYONE[END_REF] As regards this case of transient, ALCYONE is intended to predictively simulate the response of a fuel rod by taking account of mechanisms as close to physics as possible, encompassing all possible stages of the transient (for details on this aspect and more globally, the reader is referred to the comprehensive NEA state-of-the-art report [START_REF]Nuclear fuel behaviour under reactivity-initiated accident (RIA) conditions: state-of-the-art report[END_REF] ) as well as various fuel/cladding material types and irradiation conditions of interest. On the way to complying with these objectives, its development and validation shall include PWR-UO 2 fuel rods with advanced claddings such as M5® ones under "low pressure-low temperature" or "high pressure-high temperature" water coolant conditions. M5® (Zr-1.0%Nb) pertains to zirconium alloys developed with a view to better resistance to water corrosion and hydriding required in the framework of high duty reactor operation. [START_REF] Garat | M5® fulfills the new requirements by regulators[END_REF] The objective of the CABRI REPNa-11 and CIP0-2 as well as the NSRR RH-1 and RH-2 integral tests was in particular to characterize the behavior of high burnup UO 2 -M5® fuel rods under RIA conditions. With these CABRI tests performed in the former sodium loop facility, only the first stage of the transient, namely the pellet cladding mechanical interaction phase (PCMI), can be grasped. NSRR tests with water coolant conditions will be taken as a basis for addressing the second stage of the transient, should the boiling crisis occur.

Main M5® rodlet features, test characteristics, such as pulse power, coolant, initial temperature and pressure, and test results are shown in table I. Selected results of based-upon simulations related to the CABRI REPNa-11 and CIP0-2 as well as the NSRR RH-1 and RH-2 integral tests are then shown and compared to relevant available experimental results with a view to the validation of this modeling. Interestingly, this set of four tests allows to study the differences related to the coolant type, its initial temperature and the pulse width.

II. ALCYONE V1.4 RIA-RELATED FEATURES

II.A. Main modeling assumptions and capabilities

As regards material behavior modeling and laws, ALCYONE code modeling incorporates in particular fuel pellet creep and cracking (along with dish filling) and, as regards the cladding, gives the possibility to account for, alternatively or in combination when relevant:

• some temperature and flux-dependent yield stress models such as the one available for irradiated Zy4 (Ref. under LOCA conditions, which contribution is activated beyond a limit temperature. Most of models in ALCYONE code are implemented using the open source MFront code generator developed by the CEA in the framework of the mechanical behaviors and material knowledge management strategy of the PLEIADES platform. [START_REF] Helfer | Introducing the open-source mfront code generator: Application to mechanical behaviours and material knowledge management within the PLEIADES fuel element modelling platform[END_REF] MFront provides a set of domain specific languages handling material properties, mechanical behaviors and simple material models.

The ALCYONE fission gas model CARACAS (Ref. 16) deals with the fission gas creation and evolution at the grain scale. ALCYONE pulse-irradiation simulations clearly take advantage of starting from base irradiation conditions this code itself computes. With no need for any user-dependent specific initialization of the variables prior to pulse-irradiation simulations, the precise and relevant knowledge of the initial fuel rod state and spatial distribution -inter-or intragranular, in bubbles or dissolved -of fission gases is automatically ensured. Nevertheless, being not relevant for RIA conditions yet, the fission gas model calculates a negligible FGR contrary to experimental evidence.

ALCYONE pulse-irradiation simulation capability is based upon:

• the solving of the thermal heat balance equation for the pellet-gap-cladding system in non steady state conditions,

• the solving of the thermal and mass balance equations for sodium coolant in non steady state conditions,

• the same for water coolant,

• the incorporation of a material law describing the non linear mechanical behavior of irradiated M5® submitted to RIA loading conditions, • the addition, to fuel pellet creep and cracking, of grain boundary cracking modeling,

• the use of a specific hypothesis as regards the release of fission gases of the High Burnup Structure (HBS) zone. The first two points have been detailed elsewhere. [START_REF] Sercombe | 1D and 3D modeling of PCMI during a RIA with ALCYONE V1.1[END_REF] Last four points are discussed hereafter.

II.B. Recent developments

II.B.1. Non steady water heat and mass transport

Solving the heat and mass balance equations requires the estimation of the linear heat rate received by the water coolant from the fuel rod, based upon the heat exchange between the cladding outer surface and the water which involves the clad-towater coolant heat transfer coefficient (HTC) in particular. The HTC is either given together with the coolant bulk temperature or calculated using ALCYONE built-in thermal hydraulics models. [START_REF] Goldbronn | Avancées de la simulation du comportement du combustible nucléaire en 3D et en transitoire rapide[END_REF] The HTC calculation is based upon the water physical properties issued from the CATHARE thermal hydraulics system code [START_REF] Geffraye | CATHARE 2 V2.5.2: A single version for various applications[END_REF] developed by the CEA, and clad-to-coolant heat flux derived from correlations for different regions of the boiling curve (i.e. heat flux versus clad temperature) as proposed and described in Refs 19 and 20 for PWR (150 bar, 280°C, 4 m/s) and NSRR (1 bar, room temperature, stagnant liquid water) conditions respectively. The influence thereupon of the high heating rate involved in RIA is taken into account, which renders the heat flux somewhat different from the one in steady- The correlations for stagnant liquid water conditions were derived by Bessiron from inverse analyses of NSRR tests with the SCANAIR code. [START_REF] Bessiron | Clad-to-coolant heat transfer in NSRR experiments[END_REF] The transient boiling curve includes four different regimes:

• heat conduction in the stagnant liquid water up to the critical temperature (Tsat + 20 K),

• vaporization of a 30 µm thick layer of water at constant temperature (Tsat + 20 K). This semi-empirical model was introduced to account for the impact of the energy deposition rate on the CHF, • transition and film boiling regime are simulated with a heat transfer coefficient that decreases exponentially with the clad temperature up to Tsat + 450 K and then asymptotically tends to the film boiling heat transfer coefficient estimated by Sakurai, • the rewetting phase is activated when the temperature of the minimum heat flux is reached (Tsat + 450 K). The heat flux is calculated according to the same three previous correlations. In practice, the heat flux derived from the different correlations is prescribed in the thermal calculation. An explicit time integration scheme is used with a strong constraint on the time step, in particular when the CHF is reached.

These developments have been tested successfully during the recent NEA RIA benchmark Phase II. [START_REF]Reactivity initiated accident (RIA) fuel codes benchmark Phase-II, Report -Volume 1, Simplified cases results, Summary and analysis[END_REF]

II.B.2. A suitable constitutive law for M5®

Loading conditions during a RIA are quite peculiar, especially in terms of clad temperature and strain rates. A suitable constitutive law developed for M5® (see formulation in Ref. 23), supplementing the one already available for irradiated Zy4 (Ref. 10) and applicable to fast transient conditions and high temperatures representative of RIA spectrum, has been incorporated in ALCYONE. More precisely, this constitutive law aims at describing the anisotropic mechanical behavior of the irradiated M5® (fluence from 23.10 24 n.m -2 up to 150.10 24 n.m -2 , i.e. 1 to 6 annual cycles) within large temperature (from 280°C up to 820°C) and strain rate ranges (from 3.10 -6 s -1 to 5 s -1 ). It basically consists in a unified viscoplastic formulation (only one type of inelastic deformation) with no stress threshold between the elastic and viscoplastic regimes. The textureinduced plastic anisotropy of M5® is described by a Hill's quadratic criterion σ σ σ

: : M = (1)
where the equivalent stress σ is linked with the stress tensor σ via the Hill's tensor M .

The model links the equivalent viscoplastic strain rate vp ε& with σ and the viscoplastic cumulated strain p as follows:

2017 Water Reactor Fuel Performance Meeting September 10 (Sun) ~ 14 (Thu), 2017 Ramada Plaza Jeju • Jeju Island, Korea

                = ) , ( 1 ) , (
). , (

φ φ φ σ ε T m T n vp p T K & ( 2
)
where m is a parameter describing the strain rate sensitivity, K is the strength coefficient (independent on p), n is the strain hardening exponent, T and φ denote the temperature and the fluence respectively.

The Hill's coefficients were identified on the basis of test results available for recrystallized Zy4. The m, K and n parameters were adjusted on a database of around 40 laboratory test results (hoop tensile tests mainly, a few axial tensile tests and closed-end internal pressurization tests) mainly obtained from the PROMETRA program. [START_REF] Cazalis | The PROMETRA program: Fuel cladding mechanical behavior under high strain rate[END_REF][START_REF] Cazalis | The PROMETRA program: a reliable material database for highly irradiated zircaloy-4, ZIRLO TM and M5 TM fuel claddings[END_REF][START_REF] Cazalis | The PROMETRA Program: Plane Strain Tests on Fresh and Highly Irradiated Zircaloy-4, ZIRLO® and M5 TM Fuel Claddings[END_REF] The model is able to account precisely for the impact of temperature, strain rate, and irradiation damage on the ultimate stress, on the strain hardening exponent (up to uniform elongation) and on the plastic anisotropy of the material. It is suitable for simulations of unfailed UO 2 -M5® rods.

The assumed isotropic elastic deformation is described by Hooke's law assuming a temperature-dependent Young's modulus.

II.B.3. A suitable constitutive law for the UO 2 fuel

The model proposed by Salvo 24,[START_REF] Salvo | Experimental characterization and modeling of UO 2 grain boundary cracking at high temperatures and high strain rates[END_REF] to describe the behavior of uranium dioxide within a range of temperatures (1100-1700 °C) and strain rates (10 -4 -10 -1 /s) representative of RIA loading conditions was implemented in the ALCYONE code. This model consists of a hyperbolic sine model for the creep strain rate with a clear dependency on porosity, completed by a Drucker-Prager yield criterion with associated plastic flow to account for the porosity increase induced by grain boundary cracking. The yield criterion is a temperature-dependent function identified from the compression tests performed at high strain rates and high temperatures that showed significant development of grain boundary cracking. In this case, the samples' porosity and diameter were found to increase significantly showing that grain boundary cracking proceeds with pore volume increase. The latter is described in the model by the so-called "plastic" porosity.

The creep and grain boundary cracking models are completed by a smeared crack model to describe pellet cracking in tension. The resulting constitutive law is particularly relevant for RIA loading conditions where biaxial compression and tensile stress states are commonly encountered.

II.C. Ongoing improvement related to grain boundary cracking and FGR

As stated earlier, the fission gas model used in ALCYONE (CARACAS, Ref. 16) is so far not able to reproduce the FGR under RIA conditions. As this phenomenon has been evidenced as able, especially for high burnup fuels, to contribute to clad straining during RIAs [START_REF] Papin | Main outcomes from the CABRI test results[END_REF][START_REF] Lemoine | High burnup fuel behavior related to fission gas effects under reactivity initiated accidents (RIA) conditions[END_REF] , in particular through rod internal pressure increase potentially leading to clad ballooning, ALCYONE related improvement is underway. It aims at relating the FGR to grain boundary cracking and thus to the local mechanical damage of the oxide fuel generated by excessive compressive stresses.

This coupling is based upon following assumptions:

• Grain boundary cracking in the calculation is associated to the Drucker-Prager yield criterion mentioned in section II.B.3. When the associated plastic porosity exceeds a given threshold, the grain boundary is considered open. This information is then used by the fission gas model CARACAS to release instantaneously all the intergranular gas (i.e. at the grain boundaries) contained in the fuel pellet rings where the criterion is met. • In case of high burnup fuel where a HBS (characterized by an extremely fine grained structure and an increased quantity of gases at the grain boundaries) has developed during nominal irradiation in the peripheral regions of the pellet, a temperature threshold is added to the mechanical criterion to be consistent with annealing tests which showed FGR from the HBS at temperatures as low as 900 K (Ref. 28). In case the temperature threshold is reached, all the fission gas content of the HBS (inter-and intragranular gas) is released instantaneously. The gas contained in the grains (i.e. intragranular) of the HBS is assumed to be released instantaneously because the grain size is too small for diffusion to be rate-limiting. September 10 (Sun) ~ 14 (Thu), 2017 Ramada Plaza Jeju • Jeju Island, Korea

• The plastic porosity which models the dilatancy induced by grain boundary cracking is added to the strains in the thermo-mechanical computation scheme of ALCYONE and contributes therefore to the clad loading.

As stated in Ref. 25, the parameters of the grain boundary cracking model have so far been identified on few tests and their values cannot be considered as definite. Nevertheless, the proposed coupling approach takes advantage of its simplicity, based on only three parameters with a sound physical meaning: a grain boundary opening criterion which triggers intergranular FGR and can be deduced from Vickers indentation tests, a temperature criterion for the release of all the gas inventory from the HBS that comes from annealing test results, a dilatancy associated to grain boundary cracking which might be identified from porosity measurements.

The application of this approach to the UO 2 -M5® tests considered so far in this paper is shown below (cf. section III.C). It aims at illustrating how well the discrepancies in terms of grain boundary cracking-induced FGR and clad deformation are simulated.

III. ALCYONE V1.4 SIMULATIONS OF THE CABRI AND NSRR TESTS ON UO 2 -M5® FUEL RODLETS -SELECTED RESULTS AND DISCUSSION

The CABRI REPNa-11 and CIP0-2 tests and the NSRR RH-1 and RH-2 tests were performed on reconditioned rodlets from full-length commercial UO 2 -M5® fuel rods (with very high burnup fuel in the CIP0-2 test case). The main characteristics of these tests are recalled in table I.

A preliminary 1.5D simulation of the respective mother rods base irradiation prior to each one of these pulse tests was first performed with ALCYONE. And then came the simulation of the pulse tests, still with ALCYONE, the fuel column of each rodlet being simulated with ten axial slices of equal height. Unless otherwise stated, the results presented in the following figures are relative to the slice situated at the maximum linear heat rate.

Despite having no detailed data and information about the power history and axial profile of the RH-1 and RH-2 tests, some virtual cases have been shaped as follows with a view to nonetheless proceeding to simulations of (pseudo)RH-1 and (pseudo)RH-2 tests:

• the first four cycles of the base irradiation history of the CABRI CIP0-2 mother rod have been considered consistently with the 67 GWd/t burnup reached prior RH-1 and RH-2 tests; • it has furthermore been taken profit from similarities between RH-1/RH-2 tests characteristics and those, detailed, of VA-1/VA-3 tests which were available among the specifications of the 2013 phase I NEA benchmark [START_REF]RIA fuel codes benchmark[END_REF] ; • as the linear power is almost uniform along the pellet stack and the coolant is stagnant, the one-slice approximation was finally adopted in the ALCYONE analysis. All these assumptions are to be kept in mind during the analysis of the results.

The selected 1.5D and 2D simulation results presented hereafter are mainly discussed in view of the variability these four tests present between one another pertaining to the pulse width (slow or fast pulse) and the test coolant initial temperature (RT or HT).

III.A. Coolant and outer clad surface maximum temperature

The instrumentation device of the CABRI and the NSRR tests included thermocouples (TC) placed at several axial and azimuthal locations which were used to assess the quality of the heat radial and axial transfer in the fuel pellet -claddingcoolant system. Data of measured outer clad surface temperature are provided in Refs. 7 and 21. As shown on figure 2, the coolant (REPNa-11 and CIP0-2, at 3 TC axial levels) or outer clad surface (RH-1 and RH-2) maximum temperature and its time of occurrence during the pulse are quite well reproduced by ALCYONE. The discrepancy on (pseudo)RH-2 case is obviously related to the outer clad surface temperature being badly measured during the film boiling due to some thermocouple fin effect. In particular, the temperature drop due to heat conduction along the thermocouple wire in the measurement of cladding surface maximum temperature has been shown to reach 200 -300 K (Refs. 30 and 31). Therefore the measured clad surface maximum temperature and its occurrence time would not be representative of the pulse, explaining the difference calculation versus measurement shown on figure 3. The ALCYONE result compares well with the SCANAIR calculated one (978 K at 0.2 s). [START_REF] Georgenthum | Influence of initial conditions on rod behavior during boiling crisis phase following a reactivity initiated accident[END_REF] The boiling phase and rewetting are furthermore well simulated with a film boiling duration of 2.3 s fully consistent with the measured one (cf. figure 3). Commonly, during the whole short transient power period, the fuel temperature increases in a quasi-adiabatic way resulting in an almost flat radial profile with a maximum localized in an outer ring close to the pellet periphery, consistently with the plutonium content radial distribution. The closer to the end of this period, the higher the mean temperature and the larger the outer ring. The temperature at the fuel pellet centerline typically increases by about 1200 K. Then heat exchanges between the fuel rod and the coolant take place leading to a parabolic temperature profile in the fuel pellet.

Water Reactor Fuel Performance Meeting

The lower the coolant initial temperature (and the higher the ALCYONE calculated energy deposition), the higher the maximum temperature achieved in the pellet and the sharper the temperature profile near the pellet periphery. As expected, a slower pulse with a similar energy deposition, as in the case in ALCYONE calculations of REPNa-11 versus (pseudo)RH-2, leads to a quasi-disappearance of the peripheral temperature peak. Figure 5 shows the fuel pellet axial and circumferential stress radial profile evolution during the pulse-irradiation for the four pulse tests considered. Radial profiles are plotted at the same abovementioned times as for the temperature profiles. The pulse power-induced sharp temperature rise in the outer ring of the pellet generates thermal stress that puts it in a markedly bi-axial (along axial and circumferential directions) compressive stress state, as illustrated on figure 5, with maximum stress level in the [-500 MPa; -350 MPa] range. While decreasing, the compressive stress state progressively spreads radially towards the pellet center.

Water Reactor Fuel Performance Meeting

Water Reactor Fuel Performance Meeting

September 10 (Sun) ~ 14 (Thu), 2017 Ramada Plaza Jeju • Jeju Island, Korea Some code-to-code comparison between RANNS and ALCYONE-calculation results is illustrated on figure 6 for both RH-1 and RH-2 cases on the basis of RANNS results reported by Sugiyama. [START_REF] Sugiyama | Evaluation of initial temperature effect on transient fuel behavior under simulated reactivityinitiated accident conditions[END_REF] ALCYONE results are here limited to the fuel pellet. As regards temperature, ALCYONE results are globally similar to RANNS ones, even if the RH-1 centerline temperature is somewhat lower in ALCYONE calculation. As regards the hydrostatic stress, discrepancies are not surprising as the RANNS calculation did not assume pellet crack generation whereas the ALCYONE calculation does. Compressive stresses are thus relaxed so that the minimal hydrostatic stress at the pellet periphery may remain balanced.

III.C. Zones of grain boundary cracking and FGR

Figure 7 shows the radial profile evolution with time over the pulse-irradiation of the plastic porosity (with the threshold mentioned in section II.C upon which exceedance the grain boundary is considered open). Figure 8 shows a synthesis before/after pulse-irradiation of calculated gas-related quantities. Lastly, figure 9 evidences the intergranular gas and gas release fraction kinetics versus the pulse time evolution. The plastic porosity level in the pellet outer periphery clearly depends on whether the pulse is slow or fast. The lower the pulse initial temperature, the more extended the inward radial progression of the plastic porosity in the pellet and the higher its maximum level. Globally no grain boundary opening is predicted for slow pulses: even if the quite high temperature level inside the pellet allows the inward radial progression of the plastification (and the maximum inward radial progression at the end of the pulse may be similar between slow and fast pulses in case of similar injected energy), the latter remains at a too low level to trigger any grain boundary cracking. The modeling thus reproduces the fact that the grain boundary cracking does not solely depend on the burnup and consequently the grain boundary gas content. The plastic porosity localisation does match the experimental area where grain boundaries decohesion was detected through posttest examinations (in fact no decohesion in CIP0-2 and REPNa-11 case; cf. observation results of RH-1 and RH-2 rod circular cross sections reported in Ref. 7). FGR occurs only in the outmost zone of the pellet (r/r0 > 55%), during the transient power period and not solely after the pulse peak. It is completed before the end of the pulse itself and is mainly composed of intergranular gas.

Water Reactor Fuel Performance Meeting

III.D. Further discussion

This discussion on FGR and clad deformation is largely driven by related considerations by Sugiyama and Georgenthum. [START_REF] Sugiyama | Evaluation of initial temperature effect on transient fuel behavior under simulated reactivityinitiated accident conditions[END_REF][START_REF] Georgenthum | Influence of initial conditions on rod behavior during boiling crisis phase following a reactivity initiated accident[END_REF] Key elements of their analyses are recalled as a preamble and then discussed in the light of the present results synthetized on figure 10. The maximum clad residual hoop strains plotted here are ALCYONE 2D-calculation results at mid-pellet level (the reference length is the pre-test cladding diameter and not the as-manufactured one).

III.D.1. Discussion on FGR

Sugiyama statements 7 -Trying to explain the enhanced release in the RH-2 test versus the RH-1 one, Sugiyama emitted several assumptions. Having no consistent explanation related to the stress state in the pellet outer region, he suggested the higher gas release fraction in the test RH-2 could be explained by the weaker compressive stress at the pellet center, which could allow thermal expansion of the inter-and intragranular gas bubbles when the center temperature was high, should there be proved that new linkages of the gas release paths at the pellet center during the film boiling be created. Some complementary assumption related to the end pellets highly fragmented state evidenced by radiographs reported in Ref. With the present approach, not based on any thermal expansion of the gas bubbles assumption, the discrepancy among the pulses is well reproduced. The FGR of 6.8% measured for REPNa-11 seems low when compared to 8.3% measured for REPNa-4. [START_REF]Nuclear fuel behaviour under reactivity-initiated accident (RIA) conditions: state-of-the-art report[END_REF] Both tests are indeed slow pulses with similar high burnup ([31 ms | 60 GWd/t] for REPNa-11 case versus [76 ms | 62 GWd/t] for REPNa-4) and the REPNa-4 measured value is quite consistent with the posttest examinations of the rim structure and the REPNa-4 value (7.5%) calculated with the proposed approach. The FGR of 17.5% calculated for (pseudo)RH-2 is quite consistent with the measured one (15%) for the REPNa-5 pulse test. [START_REF] Sercombe | 1D and 3D modeling of PCMI during a RIA with ALCYONE V1.1[END_REF] Both tests are indeed fast pulses with similar burnup and injected energy levels ([4.4 ms | 67 GWd/t | ~110 cal/g] for (pseudo)RH-2 case versus [9.5 ms | 64.4 GWd/t | 105 cal/g] for REPNa-5). Not to mention that the coupling parameters still need to be finely fitted (cf. section II.C), the underestimation of high FGR is however noticeable and may have two origins. The first one could be the fragmentation state of end pellets as suggested by Sugiyama and the ALCYONE-calculated FGR simply corrected as follows: assuming these end pellets would have released all their intergranular gas (amounting to 21%) and the intragranular gas of the around 305 µm-thick rim zone (amounting to 4.1%), and all other pellets (12 and 2 for (pseudo)RH-1 and (pseudo)RH-2 respectively) would each contribute with the ALCYONE-calculated FGR, the ratio of the average of the total gas release weighted by the number of pellets would be closer to the ratio between the measured values (19.1/21.2 versus 21.4/26). The second origin may be sought in some uncertainty in the base irradiation power level which could have a significant effect on the calculated before pulse initial gas balance. [START_REF] Bouloré | Pending communication, UAM-11 Workshop[END_REF]

III.D.2. Discussion on clad residual deformation

Sugiyama and Georgenthum statements 7,21 -In the RH-2 case, almost all the permanent hoop strain of the cladding was predicted to occur by PCMI, i.e. predominated by the fuel solid thermal expansion, the gas-induced cladding deformation being negligible owing to too low the rod internal pressure level related to the measured FGR (26%).

With the present approach, the calculated values are in quite good agreement with experimental results and taking account of the grain boundary cracking-induced swelling allows a better prediction of the maximum residual clad hoop strain. The grain boundary cracking-induced swelling may clearly be a relevant driving force for the clad strain in addition to the PCMI due to the fuel solid thermal expansion. The underestimation (by around 0.3%) of higher hoop strains is however noticeable. As regards (pseudo)RH-2 specifically, given the computed thermal conditions of the cladding as shown in figure 3, taking legitimately account of high temperature creep of the clad material did not help to reduce it. It may have two origins. The first one might be here again the current lack of fine fitting of the coupling parameters. The second one might be sought in experimental posttest results reported in Ref. 7: experimental barrel-shaped posttest profiles of the fuel pellets were obtained where the barrel-shaped effect resulted in a maximum discrepancy of about absolute 0.4% between residual hoop September 10 (Sun) ~ 14 (Thu), 2017 Ramada Plaza Jeju • Jeju Island, Korea strain at mid-and inter-pellet level respectively. Indeed, ALCYONE 1D modeling deals with mean-pellet level intermediary between mid-and inter-pellet one.

A 3D multi-pellet scheme-based [START_REF] Goldbronn | Avancées de la simulation du comportement du combustible nucléaire en 3D et en transitoire rapide[END_REF] ALCYONE calculation is pending which may help to analyze the origin of the rather severe fragmentation of the RH-1 and RH-2 end pellets and to quantify the induced FGR. This additional release could increase the rod internal pressure to a level and local conditions that, together with local hot spots (where the critical heat flux is reached), might be conducive to higher clad straining and ballooning.

IV. CONCLUSIONS

In this paper, some 1.5D (and 2D) ALCYONE simulations of RIA transients performed on UO 2 -M5® fuel rods in flowing sodium or stagnant water coolant conditions have been compared to the relevant experimental results gained from REPNa-11 / CIP0-2 and RH-1 / RH-2 tests performed in respectively the French CABRI and the Japanese NSRR facilities. The recent and ongoing developments of ALCYONE for RIA conditions aiming at handling both the PCMI first stage and the second stage, should the boiling crisis occur, of the transient have first been briefly described, including the integration of suitable constitutive models for irradiated M5® and UO 2 as well as the coupling between the grain boundary cracking and FGR and clad deformation. The discussion of the results presented evidenced in particular the impact of the pulse width and the initial coolant temperature. With the proposed approach adopted in ALCYONE code, which differs from RANNS and SCANAIR ones, the discrepancy among the pulses is well reproduced in terms of both FGR which kinetics can furthermore be grasped and clad hoop strain even if some further improvement is needed in this latter case. The grain boundary crackinginduced swelling may clearly be a relevant driving force for the clad strain in addition to the PCMI due to the fuel solid thermal expansion.

With a view to simulating and analyzing further tests to be performed under prototypical PWR conditions within the CABRI International Program with the ALCYONE code, some further work and improvement is required first as regards the proposed modeling of grain boundary cracking and coupling with FGR and clad deformation: the parameters need to be refined for UO 2 fuel and the approach is to be adapted to MOX fuel. Furthermore, the development of gas axial flow modeling has been undertaken with a view to especially calculating whole PWR rods and not only reconditioned rodlets. In parallel, uncertainty analysis capabilities shall be improved and based upon towards a comprehensive work.

September 10 (

 10 Sun) ~ 14 (Thu), 2017 Ramada Plaza Jeju • Jeju Island, Korea state cases by impacting how boiling can develop and evolve along the clad (as shown on figure 1-left). The transient boiling curve based on PWR correlations is illustrated on figure 1-right.

Fig. 1 .

 1 Fig. 1. Clad-to-water heat transfer left: phenomenology in RIA and steady state conditions respectively (from Ref. 21) right: modeling adopted in ALCYONE -PWR case (from Ref. 19)

September 10 (Figure 4

 104 Fig. 2. Calculated versus measured value of left: maximum sodium (CABRI) or outer clad surface (NSRR) temperature ; right: occurrence time of this maximum

September 10 (

 10 Fig. 4. (Peak Power axial Level PPL) Temperature radial profile evolution during pulse-irradiation above: illustration of the plotting times considered top left: CIP0-2 case; top right: REPNa-11 case; bottom left: (pseudo)RH-1 case; bottom right: (pseudo)RH-2

September 10 (Fig. 5 .

 105 Fig. 5. Stress radial profile evolution during pulse-irradiation left: axial stress; right: circumferential stress first line: CIP0-2 case; second line: REPNa-11 case; third line: (pseudo)RH-1 case; fourth line: (pseudo)RH-2

Fig. 6 .

 6 Fig. 6. RH-1 and RH-2 cases -Comparison of radial profile evolution during pulse-irradiation of the temperature and the hydrostatic stress: (top two lines) RANNS results (Ref. 7), (bottom two lines) present ALCYONE results

September 10 (Fig. 7 .

 107 Fig. 7. Plastic porosity radial profile evolution during pulse-irradiation top left: CIP0-2 case; top right: REPNa-11 case; bottom left: (pseudo)RH-1 case; bottom right: (pseudo)RH-2

September 10 (Fig. 8 . 2 Fig. 9 .

 10829 Fig. 8. Gas concentration radial profile evolution during pulse-irradiation left: before pulse; right: after pulse first line: CIP0-2 case; second line: REPNa-11 case; third line: (pseudo)RH-1 case; fourth line: (pseudo)RH-2

  Fig. 10. Calculated versus measured values of the: left: FGR; right: maximum clad residual hoop strain

TABLE I .

 I Characteristics and results of integral tests with M5® rods (Refs. 6, 7, 8 and 9)

	Test ID.		REPNa-11	CIP0-2	RH-1	RH-2
	Performed in		CABRI reactor equipped	NSRR reactor equipped
			with former sodium-loop	with RT or HT capsules
	Mother rod:
	Cladding alloy		M5®	M5®	M5®	M5®
	Pellet	235 U enrichment, wt%	UO 2 4.5	UO 2 4.5	UO 2 3.7	UO 2 3.7
	Burnup, GWd/tM		59	71	67	67
	Number of cycles		5	6	5	5
	Corrosion thickness, µm		15-20	20 (mean)	6	6
	Hydrogen content, ppm		65/70	70/92	70	70
	RIA test on rodlet:
	Initial coolant conditions		flowing Na	flowing Na	stagnant H 2 O	stagnant H 2 O
			280°C	280°C	16°C	278°C
			0.3 MPa	0.3 MPa	0.1 MPa	6.4 MPa
	Local burnup, GWd/tM		63.5	74.5	69.1	69.1
	Pellet stack length, mm		563	559.5	117	50
	Rod filling gas pressure, MPa	0.3	0.3	0.1	0.1
	Pulse width, ms		30.8	28.2	4.4	4.5
	Peak fuel enthalpy, cal/g		92**	82**	110***	107***
	Departure from nucleate boiling (DNB) detection	NO	NO	YES ‡	YES
		Film boiling duration			60 ms	2.2 s
	Failure diagnosis		NO	NO	NO	NO
	Max. clad residual hoop strain, %	0.4	0.3	0.96	1.06
	Fission Gas Release FGR, %	6.8	not available	21.4	26
	** SCANAIR calculation; *** RANNS calculation; ‡ but no stable film boiling 7
	RT: Room Temperature; HT: High Temperature

In this paper, ALCYONE V1.4 RIA-related features and [UO 2 -M5®]-oriented specific modeling are presented first.

  10) derived from the PROMETRA program (Refs. 11, 12, 13) dedicated to the study of zirconium alloys under RIA loading conditions, • some high temperature creep models such as the one derived from the database of EDGAR tests (Ref. 14) for M5®

ACKNOWLEDGMENTS

The authors would like to thank AREVA and EDF for the financial and technical support to this work.