Marie Fayolle

Eric Quirico

Bernard Schmitt

Lora Jovanovic

Thomas Gautier

Nathalie Carrasco

Will Grundy

Veronique Vuitton

Olivier Poch

Leila Gabasova

Region M Cthulhu

Fayolle

W Grun- Dy

S Protopapa

L Young

Testing tholins as analogs of the dark reddish material covering the Cthulhu region

établissements d'enseignement et de recherche

Introduction: Pluto's flyby by the New Horizons spacecraft in July, 2015 has brought many insights into the chemical composition of Pluto's surface. Of particular interest is the equatorial Cthulhu region, whose terrains seem to contain a dark, reddish and non-icy surface material. This material has not yet been firmly identified, and might result from the sedimentation of aerosols formed in Pluto's tenuous atmosphere, from a chemistry triggered by the dissociation of ! " , !" # and !" gases [2]. Complex macromolecular organic mate- rials sharing similarities with those forming Titan's haze may then coat Cthulhu's terrains as a ~5 m layer (assuming the present deposition rate has been the same since the formation of Pluto). Here, we question this scenario through the interpretation of MVIC/LEISA data based on laboratory experiments. The optical properties of analogs of Pluto's aerosols (tholins) were determined by spectro-gonioradiometry, and were used to fit the reflectance spectra collected by the MVIC and LEISA instruments.

Experimental: Tholin samples were synthesized in a cold plasma reactor at LATMOS and recovered as a dusty material composed of spherical grains, with a size distribution peaking at ~210 nm in radius (estimated from Scanning Electron Microscopy). Two gas compositions were used, N 2 :CH 4 =99:1 and 95:5 (with 500 ppm of CO for each), relevant to atmospheric compositions at ~ 400 km and 600 km, respectively. The tholin reflectance spectra were collected with a spectro-gonio-radiometer at IPAG operating in the range 0.4-4 µm, covering the full spectral range of MVIC/ LEISA observations (0.4-2.5 µm). The absolute photometric accuracy was of 1 %, and measurements could be done under various illumination and observation geometries [3]. Measurements were carried out under vacuum and with gentle heating in order to remove adsorbed water. Reflectance measurements: The reflectance spectra collected in the laboratory are displayed in Figure 1, along with spectra calculated from optical constants published in the literature. They reveal absorption bands at 1.5, 1.75, 1.9 and 2.3 µm, due to overtones and combinations of N-H, C-H and CN [4]. Tholin reflectance spectra were collected for incidence angles of 0, 30 and 60°, and emission angles between -70 and 70° (every 10°). Their single scattering albedo (SSA) and phase function were determined through a least-squares inversion of a simplified Hapke reflectance model fitting the experimental data. Comparison with MVIC/LEISA: A direct comparison of tholin spectra and MVIC/LEISA spectra (for similar illumination and observation geometries) reveals a clear mismatch: (1) tholins have a higher reflectance factor in the near-infrared; (2) the tholin absorption bands are not observed in Pluto spectra. To get a quantitative assessment, MVIC/LEISA spectra of the Cthulhu region were fitted with a Hapke reflectance model, using the inverted tholin SSA. The surface was modelled as a spatial mixing of two units: one covered with CH # ice and the second as a mixture of H " O , C " H $ , CH # OH ices and tholins, following [START_REF] Cook | Icarus[END_REF]. An optimization algorithm has been applied to solve for the mass ratios of these compounds. This process has been conducted for two different Cthulhu spectral data, the first one corresponding to the H " O -rich region and the other one to the H " O -poor region. The best match (Fig. 2) between the numerical model and MVIC/LEISA data has been obtained with the N 2 :CH 4 =99:1 tholins. Once mixed with hydrocarbon ices, they account fairly well for the Cthulhu photometric level, but not for the visible spectral slope in the H 2 O-poor terrains, and they still display weak overtone/combination bands that are not present in LEISA observations. Three explanations, at least, are possible to account for this misfit. (1) The terrains may be contaminated by interplanetary dust impacting, bringing dark materials into the aerosols layer. However, additional experiments on tholins mixed with pyrrhotite (an opaque mineral as analog of dark interplanetary dust) and subsequent modelling led to a drop of the reflectance in the near-infrared. (2) Galactic Cosmic Rays (GCR) irradiation is known to promote dehydrogenation reactions, carbonization and perhaps amorphization. This scenario needs to be tested through experimental simulations. Nevertheless, if the dark materials of the Cthulhu terrains result from aerosol sedimentation, the effective exposure duration would not last over ~50000 years, which corresponds to a low irradiation dose. (3) A high porosity of the dark terrains is the third explanation. Laboratory experiments have shown that a highly porous tholin crust, formed from sublimation experiments, does not display combination/overtone bands in the near-infrared [START_REF] Poch | [END_REF]. On Pluto, ice/tholin sublimation, or simply low gravity deposition, may promote the formation of highly porous materials, which do not show bands in the near-infrared.

7075.pdf Pluto System After

Figure 1 :

 1 Figure 1: Tholin reflectance spectra compared to spectra calculated with optical constants from literature.

Figure 2 :

 2 Figure 2: Best optimization results for the H " O -rich (upper panel) and H " O -poor (lower panel) regions.


L Jovanovic
email: lora.jovanovic@latmos.ipsl.fr

T Gautier

N Carrasco

V Vuitton

E Quirico

C Wolters

F.-R Orthous-Daunay

L Vettier

L Flandinet

LABORATORY SIMULATION OF PLUTO'S ATMOSPHERE AND AEROSOLS

Introduction: During Pluto's elliptical orbit, the surface ices made of molecular nitrogen N2, methane CH4 and carbon monoxide CO go through a sublimation/condensation cycle supplying its tenuous atmosphere [1,2]. This atmosphere composed of N2, CH4 and around 500 ppm of CO [3,4] was suspected since the 1990's to instigate the production of photochemical aerosols [5,6]. These aerosols were finally unambiguously detected on July 14 th , 2015, when Pluto was flown by New Horizons, by means of forward scattering observations and solar occultations. Pluto's aerosols aggregate into several thin haze layers, extending at an altitude of more than 350 km [1,3,7,8].

In order to understand not only Pluto's atmospheric chemistry, but also its climate and its heterogeneous surface, simulating in laboratory Pluto's atmosphere is of prime importance. So is producing Pluto's aerosols analogues for further physical and chemical analyses.

For the very first time, we used the PAMPRE experiment [9] (LATMOS, France) to reproduce Pluto's atmosphere and to synthetize Pluto's aerosols analogues.

Experimental setup: PAMPRE [9] is a Radio-Frequency Capacitively Coupled Plasma (RF CCP) generated in a gas mixture representative of Pluto's atmosphere. For this work, the gas was composed of variable proportions of molecular nitrogen and methane, with 500 ppm of carbon monoxide [3,4]. The plasma was maintained at a pressure of 0.9 ± 0.1 mbar, at ambient temperature.

Analogues synthesis. Two types of analogues were synthetized. One with an atmosphere containing 99 % of N2, 1 % of CH4 and 500 ppm of CO, setting representative of Pluto's atmosphere at 400 km of altitude [3]. The other sample was produced from a gas mixture composed of 95 % of N2, 5 % of CH4 and 500 ppm of CO, condition representative of Pluto's atmosphere at 600 km of altitude [3].

Analogues ex situ analyses. These samples were observed by Scanning Electron Microscopy (SEM). Their chemical composition was determined by highresolution mass spectrometry (Orbitrap technique) and infrared spectroscopy.

Results:

Morphology. Pluto's aerosols analogues are spherical fluffy particles of 400 to 500 nm of diameter in average (Fig. 1). Chemical composition. Our high-resolution mass spectrometry (HRMS) study has shown: (1) a copolymeric structure of the molecules constituting Pluto's aerosols analogues ; (2) an important incorporation of nitrogen atoms in these molecules ; (3) a significant proportion of oxygenated molecules in them ; (4) an impact of CH4 mixing ratio, and so of the altitude of aerosols formation [3], as a different reactivity between N2, CH4 and CO and especially a boosted incorporation of oxygen atoms in the molecules with increasing CH4 mixing ratio.

Discussion and Conclusion:

The aerosols may impact Pluto's atmospheric photochemistry and climate by depleting the atmosphere of the C2 hydrocarbons and by playing the role of condensation nuclei for clouds [10]. This idea can be supported by the fact that in our analogues, we have detected heavy unsaturated molecules that are likely very reactive and may therefore interact with the gaseous molecules and serve as condensation nuclei.

They can also have an influence on Pluto's atmospheric thermal profile by absorbing incident solar radiations, making that Pluto's atmosphere is around 30 K colder than theoretically predicted, at about 400 km of altitude [7,11]. Due to the presence of oxygenated molecules in our samples, we can hypothesize that Pluto's oxidized aerosols may impact Pluto's radiative cooling by longer ultraviolet wavelengths [12].

Future experimental study on the aerosols/gas interactions and on the aerosols optical indices is needed, in order to further finely constrain Pluto's atmospheric models.

Fig. 1 :

 1 Fig. 1 : Pluto's aerosols analogues as observed by SEM.

Fig. 2 :

 2 Fig. 2 : Pluto's aerosols analogues as observed by HRMS.

Acknowledgements:

We are grateful to the European Research Council Starting Grant PrimChem for funding this work (grant agreement n° 636829).


Beginnings Lublin

Ludmiła Jakubczak

Wiesław Borowski

Anka Ptaszkowska

Mariusz Tchorek

Henryk Stażewski

Roman Owidzki

Edward Krasiński

Zbigniew Gostomski

Tadeusz They

Maria Kantor

Stangret

Besides

Mathilde Arnoux

Daniel Buren

Adam Chmielowski

Michel Claura

Magdalena Drągowska

Julie Fiszman

Florian Fouché

Mica Gherghescu

Barbara Gołębiowska

Francois Guinochet

Maciej Harland-Parzydło

Izabella Jagiełło

Maciej Janicki

Robert Jarosz

Michał Kożurno

Paulina Krasińska

Patrick Kremer

Maja Łagocka

Laurence Le Poupon

Isabelle Martinetti

Alice Motard

Joanna Mytkowska

Luiza Nader

Rachel Poignant

Jean-Marc Poinsot

Paweł Polit

Juliette Pollet

Andrzej Przywara

Odile Rousseau

Maria Rubersz

Aleksandra Ściegienna

Katarzyna Szotkowska

Agnieszka Tarasiuk

Iwona Wojciechowska

Waldemar Wojciechowski

Paweł Wójcik

Sara Martinetti

Maria Matuszkiewicz

Soirées Privées: a space for debates and discussions about art and politics, sometimes exhibitions too. In close association with an old brother in arms, François Guinochet, and the publishing house Éditions NOUS. The programme of these evenings is determined as much by the current moment -our preoccupations at any given time -as by our former projects. Held in Paris, the evenings are not preplanned, but rather organized spontaneously.

We stress their private nature, not worrying much about the ambiguous undertone of the French term "Soirée Privée." As in the numbered gallery that we organized in the 1970s, anything can be a subject: a debate, an exhibition, a single work or two, an excursion. The only fixture is an ample buffet (we like to use the opportunity to remember that regular galleries won't serve even peanuts, let alone the fact that after the exhibition launch the gallery owner and the collector usually sneak out to a restaurant).

The text of the inaugural exhibition declares: "Firstly, not so much exhibit 'artworks' in their 'final' form as reveal the circumstances and situations bound up with their making. Secondly, consider these circumstances and situations as organic elements of the art show."

Artists respond to this challenge by producing Europe's first examples of installation art, working in situ, to use Daniel Buren's term, in the gallery space.

MARIUSZ TCHOREK AND THE THEORY OF PLACE

The Theory of Place, ironically-pompously titled "An Introduction to the General Theory of Place," is born as the result of a night-long talk between Mariusz Tchorek and Anka Ptaszkowska on a porch in Zalesie in 1966. Tchorek reads it out with a prophetic zeal during the Symposium of Artists and Scientists in Puławy in 1966. The Theory provokes immediately a stormy protest first of all from Kantor who accuses us of plagiarism and preaches that manifests are to be written by artists, not critics. The text is then published in the Foksal Gallery Programme.

The Theory of Place (excerpts):

"Rather than looking at the artworks themselves, let us stop in front of the terrain where they find themselves. Let us not enter the exhibition, but rather stop before it.

Here is what we will constate: "Here follows a critique of the phenomenon of the exhibition, particularly its secondary character relative to the creative act."

The PLACE. So the PLACE. Certainly the PLACE.

The PLACE is an area that comes into existence through a taking into brackets, a suspension of all of the rules that govern the world.

The PLACE is not a spatial category, it is not an arena, a stage, a screen, a plinth, a pedestal, and especially it is not an exhibition.

The PLACE is a sudden gap in the utilitarian notion of the world. In the PLACE all measures in force outside it cease to be in effect. Within the PLACE there are no vacillations, because there is no difference between good and bad, worthy and worthless practice -everything simply is.

The PLACE is neither strange nor common, neither sophisticated nor vulgar, neither wise nor foolish.

The PLACE is one and one only.

The PLACE cannot be bought or collected. The PLACE cannot be arrested. The PLACE is not something anyone can be knowledgeable about."

Mariusz Tchorek remains the only person so far who has achieved an understanding of the deeper meaning of the Theory of Place and the unexpected possibility that this theory offers. According to him, the Theory of Place is the proposition of a Practice both artistic and existential. And the only path that gives access to it is that of personal and utter commitment. The Theory of Place is Mariusz Tchorek. Not only because he is its author. Mainly because he has situated it. Moreover, he has situated himself in it. And for the rest of his life.

HENRYK STAŻEWSKI -MEWA -THE STUDIO Henryk Stażewski, Henio for friends -doyen of the Polish avant-garde art movement, member of Constructionist collectives of the 1920s and 1930s: Blok, Praesens, "a.r." Co-founder, with Władysław Strzemiński and Katarzyna Kobro, of the Muzeum Sztuki in Łódź, the world's first museum founded by artists. A painter. In the 1960s, 1970s, and 1980s art world, he embodies the tradition of the avant-garde movement while remaining, until the end of his life, its active member. Totally committed. Open to everything.

Maria Ewa Łunkiewicz-Rogoyska, Mewa ("Seagull") for friends -a painter practicing "purism" in the 1930s, and later, in the 1950s and 1960s, working in the spirit of the School of Paris. Stażewski's companion. A dame of the avant-garde, Miron Białoszewski speaks beautifully about her in his Denunciations of Reality, in a chapter titled "Gioconda." They are the soul of the Polish avant-garde art community of the 1960s, its legitimation, and its invigorating force.

Their studio is the birthplace of initiatives such as Foksal Gallery, an art exchange between Polish and US artists, and many others. It is also the only credible platform of contacts with the West at the time. In the 1960s, it has three residents: Henio, Mewa, and Mewa's husband, Jan Rogoyski, who during the Stalin years provides for all three from his paycheck and tends plants on the terrace. After Rogoyski's death, Mewa, on the death bed herself, decides: "Edzio will live in Jan's room." Stażewski's cohabitation with Edward "Edzio" Krasiński will last for 20 years.

4

After the former's death, Krasiński will be the sole master of the space. It has been preserved and made accessible for the public through the efforts of Foksal Gallery Foundation as the Avant-Garde Institute.

Following my relocation to France, where Stażewski ultimately and magnanimously talked me into going, we exchanged tons of letters and, him being him, projects. Once I came to Warsaw and I saw a photograph of a woman on Stażewski's desk. "Who is she?" I asked. "Because she's similar to you," Henio replied. Knowing someone who, with his own life and example, challenged inequality between people, oppugned power and possession. Being next to an artist for whom art and its wonderful inventions are shared property. Being part of the everyday life of a fantastic man. A great gift.

Mewa in the silence of her painting and the exuberance of her life -a Person in the full sense of the word. She was a mother and guide for me. She loved us all.

Their studio -an unforgettable, priceless place of creativity, filled with life. Here and around. A place of constant meetings, discussions about art, ideas and initiatives, banquets and parties.

Someone dropping in every day: Miron Białoszewski next to Professor Żabiński, Adam "Mauzio" Mauersberger, Erna Rosenstein with Sandauer, Jerzy Tchórzewski, the Owidzkis, Boguś Choiński the poet, Kantor on his visits to Warsaw, Jerzy Ludwiński, Włodzimierz Borowski, Wiesław Borowski, Zbigniew Gostomski, to mention but those.

ZALESIE -MY MOTHER

Zalesie -my mother's house, currently the house of my daughter Paulina, Antonina, and two Aleksanders.

In times when the word "us" still made unshakable sense and included Henio, Mewa, the entire Foksal team, and random friends, Zalesie is a home to us all. In summertime a place of vacationing, meetings, parties, banquets, and ceremonies, and in winter you have to wade two kilometers through snow to the train station.

Through my mother's mad fancy, heroic persistence, and incredible spatial imagination, a house is built in Zalesie during the German occupation. After my father's death, killed by the joint forces of the Germans and the Russians in the Battle of Wytyczne, my mother builds the house alone, without a budget, with the help of sympathetic people. She quickly gets rid of the architect, builds the house "by eye," giving it delightful proportions. The wartime history of the house and of my mother's extraordinary feats is yet to be written.

Let me just recall its beginnings. As soon as the house has "come to its feet," without water or electricity, but equipped with ingenious hiding places for weapons and people, my mother arranges a café in the living room where beautiful old furniture (now nearly all sold out) and a majestic Blüthner grand piano stand on a floor on which you walk like on moving piano keys. Music performance and poetry evenings take place there, but the main goal is to feed a bunch of people: family members, partisans, those arriving from the Warsaw Uprising, hiding Jews. To provide for them all, my mother makes incredible debts. Hence mine and my sister Teresa's childhood goes by "in the shadow of the debt collector." Among our childhood entertainments is watching surreptitiously how the partisans dance the Cossack dance while shooting at the ceiling. My mother's unique charm and goodness mean that people are prepared to do anything for her.

ZALESIE -EDZIO KRASIŃSKI

In 1962, Edward Krasiński appears at Zalesie as my husband. He opens a new chapter in the history of the house. He creates it anew -unfinished yet already on the brink of ruin. This ambiguous status and atmosphere are particularly to his liking. In ways known to him, he makes it great. Using jute and a few slats, he conjures up extraordinary spaces in the attic. He pads the door to my room with black velvet and hangs a squirrel's whitened skull on it. The African mask of a cow skull brought from excavations, its horns painted gold, he hangs above the living room door. He turns rickety chairs into royal seats. He cuts small heads out of black boards and pastes our photographs on them so that we have something to lean our heads on. He covers me with a fishing-net shawl, and paints a bow tie and a vest for himself.

Next to the house grows a fantastic 300-year-old oak tree. "Others have cars, I have the oak," Edzio uses to say.

In Zalesie, Krasiński produces his first three-dimensional paintings, first spears and aerial sculptures. Here begins its course the Blue scotch tape, starting from the day when Edzio sticks it on trees in a nearby wood at the height of 130 cm, or, as he used to say, at heart height.

And if it happens that the blue tape runs across art, such as photographic reproductions of nineteenth-century paintings in ornate frames or the Battle of Grunwald, then it activates a deeply buried question: "Is this art?" And then, inevitably, "What is art?" "Art, blah blah," Edzio replies, yet pinned to his desk is a note with a faded motto: "Art is too serious a thing to be made by artists." KANTOR -HAPPENINGS Tadeusz Kantor. Who hasn't personally experienced the phenomenon of his presence, its paralyzing and enlivening power, doesn't know the most important about the man. The rest are comments more or less apt, more or less fair.

In the mid-1960s, Kantor organizes happenings, engaging the participation of a group of artists and critics associated with Foksal Gallery. The first Cricotage happening in the café at Chmielna Street in 1965; The Letter happening of 1967: eight postmen carry a 14-meter-long letter to Foksal Gallery; the Panoramic Sea Happening on the beach in Łazy in 1967 in four parts: Sea Concert, with Edward Krasiński as conductor; Erotic Barbuyage -girls-as-sardines suggestively wallow in tomato sauce on the beach; Agrarian Culture on the Sand -standing in line formation, participants plant hated newspapers on the beach; Medusa Raft -a reconstruction of Géricault's painting with the participation of members of the public. The latter consists of some 1,500 people convened unofficially, let us not forget, under the police regime of Communist Poland.

The experience of taking part in a happening is a unique experience of the autonomy of every action, object, and person. Often in spite of our Great Conductor. The autonomy of everything means, among other things, equality, and with it, freedom. Individual and, in the case of a happening, collective. It is a different version of the unforgettable lesson in equality given by Stażewski and perhaps an anticipation of the "Principe d'égalité" in the 1990s and later.

I guess I should say out loud what many think, but are afraid to utter. If I would never have dared to do that in Kantor's lifetime, that's not only out of fear of what his reaction might be, but also out of a sense of respect for how important painting was for him. But whereas Kantor's theatre was the most revolutionary theatre of his time, his painting is completely eclectic and conventional; honestly speaking, it's bad. Let's try to forget about his paintings. We will then grasp the essence of the difficult, even painful relationship. Paradoxically, Kantor's theatre owes its revolutionary quality to painting. Not to his actual painting practice, but to his thorough knowledge of the history of twentieth-century painting. Kantor elicits the essential, theoretical meaning of the revolutions that successively shook the art of painting, and subordinates theatrical action completely to Schwitters's method of collage and Duchamp's idea of the ready-made. He injects this knowledge in the living matter of his successive productions: "informel theatre," "zero theatre," "happening theatre." To my eyes, the evolution of Kantor's Cricot 2 theatre is a great animated "replay" of the revolutions that shook twentieth-century painting. Thus Kantor manages to get over representation, the holiest and indispensable foundation of traditional theatre.

THE ZALESIE BALL

The Zalesie Ball, titled "Farewell to Spring", takes place in Anka Ptaszkowska and Edward Krasiński's home and garden in June 1968, shortly after the brutal suppression of the student revolt. Many people have been thrown to prison, Niemczyk works in the real-life world. He doesn't use the protection afforded by art. In the police regime of 1960s Poland, he stages on the streets of Kraków scandalous performances that, of course, are considered criminal. He bathes naked in the fountain in front of St. Mary's Basilica, walks around with poet wings attached to his back, publicly bares his buttocks, organizes spectacular thefts at grocery stores. His self-portraits -an overdone make-up is a mask as much as a means of bodily regeneration. Aged 7, he goes naked to school, where the teachers wrap him up in a map of Poland. This is also the end of his school education.

His practices are a challenge which police henchmen and ordinary defenders of morality react in unison to. Niemczyk, meanwhile, pursues his own version of the revolution and his own method of political opposition. He pays a heavy price in prisons, in a psychiatric hospital, regularly beaten up at police stations, he dies in abject poverty.

What Kantor, himself remaining on stage, preached as the indispensable features of an artistic attitude -freedom, risk, noncomformism -Niemczyk embodied in his own life, without enjoying any protection and bearing fully the consequences thereof. Looking from this perspective, we dare to ask: what specifically can be done with the, so dear to Kantor, reality of the lowest rank? It's not like there are a hundred solutions: either to lift it or to go to the bottom. And there one may encounter Niemczyk again.

DIVIDING LINE

Dividing Line, Kantor's 1966 happening, becomes a joint manifesto for the Foksal Group circle. It dictates the modus operandi, defining the avant-garde's attitude as one of permanent opposition to all power. A sharp division between Us and Them. Them are functionaries of the official institutions of the Party and the government. Us are some artists, some critics, hippies, the riff-raff.

WE ARE NOT SLEEPING

The Foksal Group's politically most poignant presentation curated by Anka Ptaszkowska in Critics Present Artists, a show held as part of the 1969 edition of the ultra-official Golden Grape Symposium. She shows Mieczysław Dymny, Stanisław Szczepański, and Tomasz Wawak -all three being students from Kantor's class in the Kraków Academy of Fine Arts (which has just fired him) -and the Second Group, consisting of Lesław Janicki, Wacław Janicki, and Jacek Stokłosa, actors of Cricot 2 theatre.

In the exhibition, the Second Group run a stall where they accept commissions for "faithful copies" of paintings exhibited next to it, selling them for 2 zlotys to the accompaniment of exclamations: "Lowest price guaranteed," "We can be trusted," "Down with plagiarism."

In the adjacent exhibition room, three students recline on camp beds under a sign that says "WE ARE NOT SLEEPING." Close by, a PERMANENT JURY appointed to oversee the performance of We Are Not Sleeping. At the table: Krzysztof Niemczyk, Wiesław Borowski, Zbigniew Gostomski, Anka Ptaszkowska. Upon entrance, all critics participating in the Symposium receive an invitation to join the PERMANENT JURY at any time of day or night. Party authorities and the exhibition organizers are utterly surprised, stupefied. During the Symposium, Ptaszkowska presents a scandalous picture of Polish art criticism and the condition of Polish art, and reads out telegrams sent in by foreign artists and critics in support of WE ARE NOT SLEEPING. Every now and then someone takes the floor to remind those present that three artists still don't sleep in the exhibition room. Finally, Niemczyk brings the three "non-sleepers" over to the door of the room where the Jury proceeds, where they lie in the beds under a sign that says "WE WANT A REWARD."

As a result of this event, Foksal Gallery faces closure, Ptaszkowska receives a threat-ridden reprimand from the Party and ministerial authorities, and a press scandal rages on for months.

The idea of not sleeping comes from Kantor, but the actual leader and strategist of this mini-revolution is Niemczyk. He brilliantly seizes upon the moment of the authorities' confusion at the sight of WE ARE NOT SLEEPING. He bombards them with more slogans: "Only sleep ensures impunity," "We haven't told you good night," "We demand an inspection," and finally, "We'll be back." The official banquet is an opportunity for the apparatchiks to throw all kinds of threats at me. And suddenly, in the terrible silence of concentrated fear, Jonasz Stern, a pre-war Communist and Holocaust survivor, untouchable even for the Communists, crosses the banquet room and kisses me cordially. The fear is gone, solidarity is born. And Niemczyk tells me: "Go to the Ministry right away or they'll close the gallery." Come morning, I appear before Department Director Kuduk who only yesterday fulminated at me. I demand funds for Cricot's trip to Rome and Foksal Gallery's participation in the Salon International de Galeries Pilotes. Received like a queen, I get the funds without any further discussion. I congratulate Niemczyk for his keen sense of the psychological meanders of corrupt power.

NEW RULES OF COLLABORATION WITH FOKSAL GALLERY

"We hereby announce a break in Foksal Gallery's activity as a site of exhibitions, happenings, and artistic manifestations of all kinds. The Gallery has realized that it is a privileged place -a place where everything is possible. Possible and legitimate.

So act beyond it as you would act here! Everything is possible, everything is legitimate. Act in non-artistic places (that is a condition of our collaboration), in public or private (depending on your preferences).

The Gallery undertakes to document your activities and inform the public about them.

An open, public, and permanent media briefing will be held at the gallery.

Send us your materials (photographs, films, accounts, documents). You don't need to trouble yourselves personally.

You don't have to cover the cost of shipping your works. Nor do we."

This open invitation to a revolution becomes one of the reasons of the break-up of the Foksal Group. Kantor vehemently protests against the idea of a Critics ' Gallery,13 in the name of that of an Artists' Gallery of course. Niemczyk's reaction to the "New Rules" is immediate. His innocent action, Today It's the Waiter Who Tips Us, has the Kraków police on their toes. After an "anonymous tip" offered by Niemczyk himself, the market square and the streets leading to the Grand Hotel restaurant are blocked, and the happening participants convened there are arrested and brought to the station. The police plays its role, but according to a script written by Niemczyk.

MÈTRES AVANT PARIS

Our beginnings in Paris: a jump without a parachute, cheerful poverty, anonymity, doing physical work and serving the bourgeois to earn a living, but high jinks in the Montparnasse in bars open until morning, meeting strange people. Goodbye, art! Goodbye forever! For whole days we wander around Paris with a baguette in hand. Eustachy Kossakowski, a Rolleiflex camera slung on his shoulder, notices a sign that says "PARIS". "That's worth photographing," he says. Thus begins our great adventure of discovery. Questions waiting to be answered: What is this sign for? Is it one or many? How many? Installed where?

The result of our long-time explorations: there are 157 such signs. They stand on the administrative border of Paris, where the streets leading from the suburbs enter the city.

Kossakowski's decision: to photograph them all, from a distance of 6 meters, with the word "PARIS" in the centre. He chooses one and the same point of view for 157 compositions, attesting, paradoxically, that their number is infinite. This strict rule opens the door to chance. The word "PARIS" means that all views are beyond any doubt views of Paris. Only no one has ever seen, or rather wanted to see, such Paris. We are perversely pleased by the amazed questions: "This -this is Paris?" Kossakowski's sister, Barbara, says: "No one has realized it's a prank." The first one: mid-1960s, the Foksal era. Thanks to the censorship office, which allows only materials from "proven" sources to be brought into the country, we regularly read Les Lettres françaises, the culture weekly published by the French Communist Party and edited by Louis Aragon. There we encounter texts by Daniel Buren, Michel Claura, and René Denizot. They resonate closely with our own reflection on the social functioning of art that we express in our manifestos. I translate them rather clumsily into Polish and they circulate from person to person. Stażewski declares in his characteristic, half-joking, half-serious manner: "I announce to you the appearance of the most important artist of our era. His name is Daniel Buren." 15 16

The second meeting: Paris, 1970. After the break-up of Foksal Gallery, I abandon art "forever." But I want to meet Buren. I go with Edzio to his exhibition launch at Yvon Lambert Gallery. I expect to see "all of Paris" there, but it's five persons. I feel very shy when Lambert introduces me to Buren: Anka from Warsaw. Buren has just returned from the Tokyo Biennale where the critic Yusuke Nakahara, who had invited Krasiński to participate in the event, told him: "If there's one place in the world where you are truly appreciated, it's Warsaw."

In Buren's studio, we meet his closest circle: Michel Claura with Brigitte, Seth Siegelaub with Rosalind, Niele Toroni with Dalmas, Philippe Sers. All, except Sers, politically far on the left. Hopefully awaiting from us news from a "better world." Our vehement anti-Communism, which we voice thunderously, shocks them. But the deep ideological divide doesn't prevent us from becoming friends and working closely together.

GALLERY 1 -36

In 1972, together with Michel Claura and François Guinochet, and in close association with Daniel Buren, we launch a gallery with me as its director. The gallery changes its name with each consecutive show: Gallery 1, Gallery 2, Gallery 3, all the way up to Gallery 36.

Funding comes initially from the collector Herman Daled and from Guinochet. A series of exhibitions and presentations takes place in a basement at 17 rue Campagne-Première in Montparnasse.

But this is a gallery without a name or a fixed abode. A numbered gallery that shows truly critical art. Critique is inherent to its very idea. Each successive incarnation is unique (the numbers never repeat themselves), but it is also representative of a genre, more still: it is a genre itself. We show minimal art and conceptual art by international avant-garde artists. The gallery can be an exhibition, a concert, a performance piece, a film, a debate, a meeting -almost anything.

GALLERY 5 Invitation to the presentation of Gallery 6. GALLERY 6 Exhibition of 10 young artists, each showing 10 works. Participating: Trbuljak, Charlier, Rutault, Roquet, de Boeck, Yokoyama, Sauerwein, Clément, Guinochet, Cadere.

GALLERY 7

In accordance with an accepted system of rotation, the show changes every day. We reveal the crucial role of context which every exhibition imposes on the artist. It is a mill for grinding artworks, annihilating them. We stress that ours is not different from other exhibitions, but exactly the same. With the difference that the artists know beforehand.

GALLERY 10 Vincent d'Arista, a Naples-based artist brought to my attention by Lucio Amelio, uses donkey-driven carts to bring several tonnes of old rubber tyres to the top of Vesuvius. He sets the tyres on fire. Billows of smoke, a panic, hundreds fleeing the city, certain it's an explosion of the volcano. In another project, he adds a fifth lion to the four marble on Piazza dei Martiri in Naples. D'Arista plays a "shot in the dark" game with me. He has me order pneumatic hammers, hydraulic rams and the like from a tool rental store. It's clear that his "shot in the dark" means the physical destruction of my gallery. But I keep it cool and order everything he wants. He ultimately chickens out and shows my picture captioned: "Anka Ptaszkowska -director of Gallery 10."

GALLERY 23

A Loop Seen as a Line -a film screening and exhibition by the Japanese artist Taka Iimura. For hours, sitting still, we watch tiny vibrations of stretched film stock. Cultivating boredom. Defying the "society of the spectacle." GALLERY 34 Exhibition by Carl Andre: 2 Segment Hexagon, 3 Segment Hexagon, 4 Segment Hexagon. A beautiful installation on the gallery's white floor. Gifted by Andre to the ultra-left periodical POUR écrire la liberté edited by Isi Fiszman. Acquired by Pontus Hultén for the collection-in-the-making of the Centre Georges Pompidou despite a concentrated assault by international dealers who swarm to Paris to talk him out of the idea. Strong market pressure, but fortunately, in Hultén's case, ineffective.

GALLERY 35 -HIROSHI YOKOHAMA GALLERY 36 -BERTRAND WICQUART In 1976, my gallery goes bankrupt and we lose the basement at Rue Campagne-Première. A real estate agent, Claura's friend, lets us use for a month a several-story building at Boulevard de Sébastopol. We stage exhibitions by Hiroshi Yokoyama and Bertrand Wicquart on the upper floors. Communication between them is by elevator. It's a big Paris event. In the footsteps of New York, the first "galleries' house" in Paris. A grand-style swan song. The unexpected visit of Tamás Szentjóby, who in 1967 had illegally crossed the border to take part in Kantor's Panoramic Sea Happening. Upon his appearance, a fire breaks out in the complimentary building. Horror. But the firemen manage to put it out without any major damage. Years later, I learn about Szentjóby's mysterious ability to start fires at will.

GALLERY ROADSIDES IN THE 1970S

I meet Gérard Lebovici, a major patron of Guy Debord and the Situationist International, owner of the publishing house Champ Libre. Because it's far too early for "my" artists, the sale of their works through my gallery is a rare occurrence. The gallery's existence is greatly supported by Stażewski who, with his characteristic magnanimity, gifts me his paintings and even exempts me from the re-sale tax. But still I'm constantly on a desperate hunt for funding. And then one day Gérard Lebovici himself walks in. He inquires with me to find out what we are about. I tell him about our debunking agenda, and I can feel that we're on the same wavelength. It's complete rapport until the last question, which he asks as a pure formality: What is my political involvement? I can still hear my answer that after the experience of real socialism I want nothing to do with politics, and I see disappointment in his eyes.

Even if in an erratic manner that is sometimes characteristic for me, I still involve myself, and the gallery too, in efforts to support the ultra-left POUR écrire la liberté, a periodical run by Isi Fiszman. Isi is a well-known collector of avant-garde art, of Marcel Broodthaers, Hanne Darboven, Panamarenko, or Joseph Beuys, among others. He comes from an Antwerp family of diamond cutters, their roots in Łódź, Poland. Because of his pro-Palestinian sympathies, Isi is banned from visiting Israel. He appeals to artist to donate works to support POUR. Donations flood in, because artists at the time liked to consider themselves as ordinary workers. Therefore, the growing prices of their works throw them into moral discomfort. With Isi, we begin a joint adventurous sale of the donated works. We slip through the Swiss border in a van full of "uncustomed goods," with Isi's dog (who had access to all museums of the world) by the steering wheel. In Venice, we propose to Peggy Guggenheim to stage a show at her Foundation, a rather insolent proposal. Unbelievably, we get a free stall at the first FIAC in Paris and at Art Basel. We stand silently under Beuys's work Dürer, ich führe persönlich Baader und Meinhof über die Dokumenta V. Baader and Meinhof are, of course, police-sought terrorists. The sale of Carl Andre's work for the Centre Georges Pompidou collection (see Gallery 34 above) is one of our financial successes.

FRANÇOIS GUINOCHET

Let me briefly reveal his extraordinary story. Due to Guinochet's incredible modesty and discretion, hardly anyone knows it. In 1967, at age 18, he organizes at his home in Lyon the world's first exhibition of Daniel Buren and of the group Buren, Mosset, Parmetier and Toroni. He takes part, as an artist, in the first exhibitions of conceptual art staged by Michel Claura and Seth Siegelaub. He is politically deeply committed, close to the Situationist International. One day he resigns his status as an avant-garde artist and goes to the Place du Tertre where he paints for tourists, and paints well too. The purpose of this operation is a political one: to compare the avant-garde art market with that of kitschy painting. But Guinochet's "modern," as he called them, views of Montmartre unexpectedly become a hit. He is able to co-finance our numbered gallery, builds up an excellent library, supports and collects selected artists. Raymond Hains is probably on top of his list. Mid-1970s: the avant-garde in an artistic and intellectual crisis. The war declared by conceptual artists against the art market under the battle cry of "Art is not a product" ends in a fiasco, that is a financial success. Ambitious galleries, like Wide White Space, shut down. In the sterile white of the other ones, equally sterile shows take place. New Figuration, Trans-Avant-Garde, Bad Painting march triumphantly onto the stage.

Our belief that galleries no longer matter leads to the idealistic conclusion that they will cease to exist. With Michel Claura and Brigitte Niegel, we open Vitrine pour l'Art Actuel next to the emerging Centre Georges Pompidou. It is the first alternative space in Paris: a bookstore specialized in artist's books, exhibition catalogues, independent international art periodicals. Irregular artistic events take place here, but not exhibitions. In the display window -photographs from exhibitions worldwide. An à volonté buffet. A memorable event: a concert by Jeffrey Lohn and Glenn Branca's New York rock band Theoretical Girls. With indescribable vehemence, the band shout out their hatred of the art world. A big event, a dense crowd, the street barred off. Order is kept by pimps from bars we are friends with, and they act with true seriousness and enthusiasm. We are in Rue Quincampoix, famous for its paid-sex offer. It remains so until the day when artists flocking in to be close to the Beaubourg museum write a petition to the mayor, complaining that the "street girls make it difficult for them to work." With this show, Krasiński provides answers to several questions. How to publicly exhibit a private place? Krasiński's answer: by taking from Stażewski's studio its photographic views and placing them next to real ones. How to replace Stażewski's paintings, of which only white rectangles on the walls are left? Answer: With one's own work. How to make present a personally experienced absence? Answer: by concretizing the memory of someone powerfully enough to prevent it from becoming a reminiscence.

Krasiński proposes a precarious situation. He is fully aware of the risk he has taken. I've never seen such jitters as in Krasiński on our way to the opening. The situation arranged in the gallery is like a miracle, because the public accepts it as something natural. People intimate with Stażewski's studio have no doubt that here we find ourselves in it, or towards it.

RECONSTRUCTIONS

Reconstructions, or relocations. Relocations with the benefit of inventory. That's probably a better term than "exhibiting." Krasiński relocates the studio to his favourite restaurant, Gruba Kaśka, to a butcher's store, to the Zachęta National Gallery. At some point, the view of the studio from the door facing the corridor is cut into long strips. To make the relocation easier, we'd like to believe. But if we remember the re-enactment of Bruegel's Land of Cockaigne, we will probably discover here a genuine need to be in another time, in a different place. But probably not in the skin of another artist. But why not in his painting? Let's not forget that Krasiński in his youth drew and painted like the Old Masters. Perhaps in his courtly life he also took part in tableaux vivants.

Today, Krasiński's studio is the Avant-Garde Institute. A masterpiece of the art of conservation. And a proof that for an institution -and an artistic institution at that -altruism can be a virtue. The Foksal Gallery Foundation carries out the complex, costly, and delicate work of preserving the space that Edward Krasiński lived in and created on a daily basis. The place has been preserved so meticulously that dirt remains dirt, no longer being dirty. The terrace is being converted into an exhibition pavilion. Subtly dosed exhibitions and events are held here.

PRINCIPE D'ÉGALITÉ

A phenomenon is based on an organic cooperation of contradictions: an aspiration to equality is dynamized by its opposite, and a constantly renewing hierarchy becomes a driving force of equality.

With Benoît Casas, the future founder of Éditions NOUS, I run a seminar under this title at the School of Fine Arts in Caen. We open the seminar with students in 1993 at the Muzeum Sztuki in Łódź in a colloquium devoted to Władysław Strzemiński. The first sentence of the keynote speech is a quote from Unism: "Every square centimeter of the painting has the same value." We trace and catalogue the egalitarian tendency in twentieth-century art history, without, of course, ignoring its social and political applications.

EQUAL ASCENT. A proposition by Mariusz Tchorek whom I invited to participate in the seminar. The Principe d'égalité introduced in interpersonal relations. This collective experience of being in equality takes place at the most hieratic place that is the Lower Normandy Regional Council building. Over a dozen students take part. Tchorek organizes a space of encounter that precludes the creation of any hierarchy and he is the meeting's attentive participant. After eight hours, we leave the place with a feeling of previously unknown lightness.

ANDRÉ DU COLOMBIER

In artpress, I called him provocatively (but was it only that?) a genius. He was certainly the only genuine Dadaist that I've met. Highly educated, from a family of philosophers versed in Deleuze's seminars, half-Romanian, born in Barcelona, secretive, living off nothing at the utter margins, uncompromising, surprising, haughty, arrogant towards people of social or artistic prestige, gentle towards all others. He made art everywhere and out of everything, as a gift or for stellar prices. Language is his privileged area: "modéstie, compétence, efficacité" (modesty, competency, efficacy). Words, sentences hastily written on colour papers, arranging themselves into sequences of meanings overt and covert, surprisingly simple and so complex that not 25 26 27 always graspable. A demanding and exclusive art, but nonetheless an "art for all." Individual and shared by few -an attempt to transform the world.

One day du Colombier went to a police station in Paris to lodge a complaint against the Museum of Modern Art. He was thrown out. He went to the next station, was thrown out again, finally reached the Central Police Station, whence he was sent away to the madhouse. He managed to get out following the intervention of Pontus Hultén, director of the Musée national d'art moderne, which is not an innocent paradox. Du Colombier was never accepted by the Paris art world, which is a euphemism for the ostracism that he experienced and always responded to in his exclusive and aloof manner, with humour both sophisticated and offensive. To this day he has followers among those broad-minded enough. Together with François Guinochet, we keep protecting his work from disregard and oblivion. For example, the term "work." In the contemporary art world, it means its result, that is the artwork. In her practice, Poignant restores the word "work" with its original verbal meaning. The subject of her work is work itself. And this isn't a tautological little game. It means totally committing your whole life to the artistic process, not its result. This is work without prospects for a final product, selfless and demanding. And the reward is quality. A matter of price? This is not about the price paid to the artist, but the price that the artist pays themselves. In Poignant's case, it is very high; it includes the mystery of her sculptures' quality.

PLACE OF THE AVANT-GARDE

I don't think it will be bombastic to say that there is no place for the avant-garde in today's society. Its end was announced long ago. On that occasion, it was criticized for directivity, historical determinism, commitment to the idea of progress and so on. Let me start with a question: does the fact that we don't constate the avant-garde's manifestations in current life mean that it's dead? I'm in no hurry to come up with an answer.

But I will answer the question of what was the historical avant-garde's true enemy. It was LIE -social, political, and religious -present in the collective consciousness. Yet the place where the avant-garde of recent years sought to make a presence was public space. A space filled with lie as tightly as never before. So is there a place for the avant-garde in the present-day world? I will leave aside the too-difficult question with a too-easy answer: "Can art remain its territory?" The avant-garde's last manifestations that I know of were individual attempts to wrench moments of anti-lie out of public space (Krzysztof Niemczyk, André du Colombier). Those, I repeat, were individual attempts, paid for with their own life. They are closely connected with what I consider to be the last aspiration of avant-garde art: an individual refusal of power. In the personal realm and the public one. Thus is born the chance that the personal will feed through into the sphere of the collective. The condition of this transformation: ADEQUACY, an inherent part of the principle of EQUALITY.

  than three persons are banned. The Ball is attended by some eighty brave guests from all over the country, including Kantor and Maria Strangret straight from the May revolution in Paris. An amazing scenery. Krasiński reconstructs Bruegel's Land of Cockaigne around the 300-year-old oak three, a cart of vegetables as a tribute to Arcimboldo. Gostomski erects the Table for Giants, Krzysztof Niemczyk, in a top hat wreathed with jasmine, plays a concerto by Tchaikovsky at 5 a.m. on the old Blüthner. Intense partying goes on for three days and three nights. Police cars, lights off, stand in the neighbouring streets. But they don't intervene. In 2006, Paweł Althamer, in association with Paulina Ołowska and Joanna Zielińska, produces a kind of re-enactment of the Zalesie Ball in the gardens of Warsaw's Centre for Contemporary Art, a project curated by Paweł Polit. After nearly 40 years, as the title of Althamer's project proclaims, the Ball is revived. KRZYSZTOF NIEMCZYK Niemczyk writes, passionately plays the piano as an autodidact, and paints. Besides several short stories, he is the author of the novel The Courtesan and the Hatchlings, which enjoyed cult status in the 1960s. First published in France in French by Éditions de la Différence in 2003, and in 2007 in Poland by Wydawnictwo Ha!art in one volume with Krzysztof Niemczyk's Treatise on Life for the Young Reader. In the 1960s, Henryk Stażewski writes a manifesto, Scandal in Literature, in defence of The Courtesan and the Hatchlings.

  Kantor's Dividing Line divides and accuses. Translated faithfully into French, it becomes the Ligne de partage, the line of sharing. It is under this title that the magazine Ohm publishes an extended interview with me. Years later, Cezary Wodziński, writes in one of his letters to me: "Dividing Line. What a monstrous metaphor." WHAT WE DO NOT LIKE ABOUT THE FOKSAL GALLERY? To realize that we act within a HABIT! To find out and reveal what is HABITUAL in our behavior! Rule of time Creation is always PRESENT. We should have no more use of the calendar with its divisions into years, months, days and nights. For artistic ends it is unnecessary and encumbering. Let us not waste time! Let us get rid of it! 10 11 Rule of place To the question: when? We answer: NOW. To the question: where? We answer: EVERYWHERE. Let ACTION dislodge and defame performance.

  : "What did being a photographer mean to you?" "A fine-art photographer? No no… I'm a photographer." It meant that your eyes were open -permanently, in 360-degree vision. You used to tell me: "But you don't see half of the things." Your position in the art world is clearly defined: you are the one who sees -an observer. You've never claimed the status of an artist. Whereas the professional participants of artistic life claim boldly: "I create, I'm an artist." Your career of one of the best photographers in 1960s Poland is impeded by a sober reflection: Why is it so that shifting the camera by a few millimeters makes all the difference between a masterful shot and a failure? To avoid this dilemma, you permanently challenge the established point of view. A sense of humour and a spirit of opposition help you in this. You photograph the Twelve Apostles on the frontage of St. Peter's Basilica in Rome from the back. You turn your back on the famous stained glass windows at Chartres Cathedral -the untiring subject of thousands of photos -and instead for 7 years you capture the interplay of the lights and colours thrown by the windows on the walls of the cathedral. You regularly press the shutter release, recording the progress of light in the series A Window on Rue Dareau and Light in the Corridors of Chambres de Bonnes. In dark Pompeian villas, you capture sun rays that, instead of illuminating interiors, intersect and ruin them. You take a picture of the flag of the Doge's Palace in Venice straight against the sun. For why should you shoot with the sun and not against it? Why go with the grain rather than against the grain? Defying the whole tradition of European painting, you don't consider light as something that illuminates form, renders it visible. Instead, you photograph it as an object -an autonomous object. This requires truly Promethean audacity. DANIEL BUREN Two meetings.

  Together we launch out into the work of André du Colombier and later Rachel Poignant. Guinochet has an infallible eye for art. If he had possessed a commercial instinct, he would probably have been the greatest dealer of his time. But what he values above anything else is his freedom, in other words: unselfishness. These days, together again, we organize Soirées Privées in Paris. MICHEL CLAURA Michel Claura, a renowned 1970s art critic, who organized the first exhibitions of conceptual art, including discussions with Ian Wilson. To this day we remain closely in touch and work together whenever Michel has time and feels like it. I could talk 19 20 about him for a long time. But let me just quote one sentence by Anne Tronche: "Because of Michel Claura, we thought for a long time that Daniel Buren can't write." VITRINE POUR L'ART ACTUEL

  ÉCHANGE ENTRE ARTISTES POLOGNE-USAIn 1981, working with Pontus Hultén, former director of the Musée national d'art moderne and a co-founder of the Centre Pompidou, later director of the Museum of Contemporary Art in Los Angeles, I organize a direct exchange of artworks between Polish and American artists. Endorsed by Henryk Stażewski, its historical precedent was the First International Collection of Modern Art, created with artists' donations.Here, too, it is not institutions, not museums, but artists themselves who set the terms of the exchange. The Polish collection goes to the MOCA, the US one to the Muzeum Sztuki in Łódź. Both "meet" in a joint show at the Paris' Museum of Modern Art in 1982. In Poland, it's martial law. The country sealed off from the world. The Polish artists' works arrive in Paris illegally with a shipment of medicines. Asked why an exchange, I reply: "To take money out of the game."STAŻEWSKI -BUREN -KRASIŃSKITheir long-time association is an extremely rare example of community between artists resulting directly from their artistic attitudes and agendas. In spite of political and geographical distances, with no institutional support, beyond any self-interest. 1970 A Buren-Krasiński meeting in Paris. In Buren's studio, Krasiński sticks on Buren's work, Bandes verticales blanches et noires de 8,7 cm de large, a piece of blue Scotch tape at the precise height of 130 centimeters. It's their joint work now. On the following day, Krasiński sticks the blue tape on the display windows of Rive Gauche Gallery and in the courtyard of the Museum of Modern Art. Accompanying him are Buren, Erik Veaux, and myself. 1974 Stażewski invites Buren to stage an exhibition at his studio. Gallery 21 "sponsors" the event. Buren's in situ work on the windows of the studio and of Repassage Gallery during a Krasiński exhibition. Accompanied by his friends, critics Michel Claura and René Denizot, Buren's visit is ripe with events. An exhibition launch in Stażewski's studio. A debate with members of the Warsaw art scene at Repassage Gallery. The vivid memory of huge platters of crayfish and chilled vodka served at Pod Samsonem in soda bottles before the magic hour of 1 p.m. when liquor could be officially sold in Communist Poland. 1985 Stażewski invites Buren to participate in Dialog, an exhibition at Stockholm's Moderna Museet. Buren builds the Cabane éclatée n°9, on the walls of which he displays Stażewski's paintings. The Cabane n°9 is then shown in Stażewski's exhibition at the Polish Institute in Paris in 1997. In a conversation with me published in the catalogue of that exhibition, Buren talks beautifully about his friendship with Stażewski, how in response to the invitation to Warsaw he built the hut to receive Stażewski's paintings. Today, the Cabane éclatée n°9 is on permanent exhibition at the Muzeum Sztuki in Łódź as a pendant to Strzemiński's Neoplastic Room. 1993 Buren comes to Warsaw and for the centenary of Stażewski's birth recreates the 1974 works on the studio's windows; he also takes part in a 22 23 festival focused around the work of Edward Krasiński, organized by Biblioteka Gallery run by Stefan Szydłowski. EDWARD KRASIŃSKI: HOMMAGE À HENRYK STAŻEWSKI Edward Krasiński's exhibition, Hommage à Henryk Stażewski, at Foksal Gallery in 1989, a few months after Stażewski's death.

  with Raymond Hains like I happened to work with Stażewski, Kantor, Krasiński, or du Colombier. Still, our relationship was more than just mutual sympathy and friendship. Hains was very fond of Kossakowski and greatly appreciated his work. During the launch of an exhibition of Kossakowski's photographs at Galea Gallery in Caen, a taxi from Paris suddenly arrived and, to everyone's surprise, Hains stepped out of it. And one day he told me with his benevolently mocking smile: "On va se marier, Eustache va être notre témoin." (We are going to get married, Eustachy is going to be our witness) RACHEL POIGNANT My personal and consistent commitment to the art of Rachel Poignant stems from the fact that she keeps returning to questions that we considered as fundamental back in the 1960s and 1970s.

NOUS

  Run by Benoît Casas and Patricia Atzai, the publishing house Éditions NOUS has already published over 100 volumes of philosophy and poetry. It publishes authors whom I appreciate and resonate closely with, although I don't fully share the NOUS team's radical political commitment. With Benoît Casas, I shared the same view of art and society in the seminar that we jointly taught, titled Principe d'égalité. Éditions NOUS has also published Eustachy Kossakowski's 6 mètres avant Paris photo-book, is preparing his monograph and the monograph of Rachel Poignant. Together we organize my Paris "Soirées." We really have a close relationship.

  Henryk Stażewski: adjectives read out horizontally by Anka Ptaszkowska at the Muzeum Sztuki in Łódź on the centenary of his birth:

	authentic	good	layman	playful
	delicate	gourmet	methodical	realist
	discreet	independent	modern	shy
	elegant	individualist	naïve	spot-on
	erotic	ingenious	natural	unbiased
	ethical	innocent	nervous	unselfish
	European	innovator	non-believer	wise
	farsighted	intelligent	open-minded	witty
	frank	internationalist	pacifist	youthful
	frivolous	joker	painter
	What do I owe to him?

Thanks to Dan Graham for the title: "ANKA-BIRD-WOMAN". Never would I have given such a title to an exhibition, if it were to be mine -for the following reasons: -Its pretentious ring -on first, but also second thought.

-The inclusion of the word "WOMAN", in the wake of that irritating fashion which all-too-facilely claim continuity with feminism. I would not have allowed myself to brandish this word in an attempt to elicit approbation from the ladies in the audience.

-Considering, finally, the presence of my name.

But when it is YOU, DAN, who comes up with the title for my exhibition, Anka-Woman-Bird, in memory of an ancient legend, I abandon all misgivings and find great beauty in your coinage. Even more so, when it fends off immediate graspability.

I thank you for this, just as I thanked you for the title of my only book: I believe in freedom, but my name is not Beethoven.

When I heard that Dan died, on January 19, 2022, it was one of the saddest news I have ever received.

I GIVE THANKS TO:

HENRYK STAŻEWSKI for my youth, which I was fortunate to spend in his studio. For his lesson in equality among mankind -of which he set the best example. For the generosity that characterized the circle he formed with MEWA and from which we benefit daily.

MEWA-MARIA EWA ŁUNKIEWICZ-ROGOYSKA because she was a real lady, intelligent and loving. And for her love of France, which she instilled in me.

ALINA OXIŃSKA my mother -for the wisdom in her madness.

IRENA JURGIELEWICZOWA

for what she could prove to be and for her role she played in my early artistic endeavors and the "nay-sayings" of my youth.

PROFESSOR ŻABIŃSKI, HEAD MANAGER OF THE WARSAW ZOO for correcting my first articles.

TADEUSZ KANTOR for THE HELL OF THE AVANT-GARDE, which he helped me cross. For all the vistas through the realms of the IMPOSSIBLE he took me through, and for the only live experience of my life in theater.

MARIA STANGRET-KANTOR for the good and the bad.

WŁODZIMIERZ BOROWSKI AND JERZY LUDWIŃSKI for the first steps we took together and their future consequences.

JACEK WOŹNIAKOWSKI because he knew how to impart to me his faith in the validity of individual revolt, even in its more trivial instances, as colored stockings can be.

MIRON BIAŁOSZEWSKI because he was there.

BOGUSŁAW CHOIŃSKI ditto.

EDWARD KRASIŃSKI for wanting to be my husband and for what MARCEL ANDINO had in mind when he claimed that "Edzio was a saint".

EUSTACHY KOSSAKOWSKI for everything.

MARIUSZ TCHOREK for his creative thinking and unique understanding of the most demanding artistic endeavors -like those of Katarzyna Kobro and Władysław Strzemiński.

ERIK VEAUX for the precision and lightness of touch (which rarely goes together) of his translations into French, and for his unwearied generosity in trying times.

KRYSTYNA DAJBOR for her gift of acceptance -without conditions.

ZOŚKA PASZKOWSKA my friend since I was young.

FRANÇOIS GUINOCHET Because he is unlike anyone else.

MICHEL CLAURA

for what he taught me, past his ironic smile. DANIEL BUREN who managed to convince me that art can change the world.

ANDRÉ DU COLOMBIER a constant artist, who never backed down from anything.

BENOÎT CASAS for the courage of the "endless painting" and for the Éditions NOUS.

ISI FISZMAN for having endowed with humor a prophet of the Old Testament, of which he was himself the incarnate image.

RACHEL POIGNANT for giving back its true meaning to the word WORK.

CHARLES DUPLAIN for his commitment and work in benefit to Eustachy Kossakowski's archives and my various actions and publications.

KOJI KAMOJI because he doesn't back down from anything.

LAURENT PREXL for his prescient action, Free Transport, in the early seventies, and for the Suite.

KRZYSZTOF NIEMCZYK for the individual revolution he led alone, against all odds. CEZARY WODZIŃSKI -MAN AND PHILOSOPHER.

CEZARY WOŹNIAK and ANTON MARCZYŃSKI

for the complicity… JOANNA MYTKOWSKA and ANDRZEJ PRZYWARA for their understanding of art, based as much on sensitivity as on awareness.

For the difficult choice they made one day, and for their loyalty.

ADAM SZYMCZYK for his talent for seduction or -depending on his mood -for deception.

For the accuracy and scope of his undertakings.

ARTUR ŻMIJEWSKI for his intransigence.

PAWEŁ ALTHAMER for his "classical" statues, which amazed me, and for reviving the "Ball in Zalesie". WILHELM SASNAL because after visiting his exhibition, I wanted to visit it again.

JEFFREY LOHN for the music he generously shares and for his resemblance with Franz Kafka.

AGNIESZKA TARASIUK who, at her own expense, set out to save the honor of an institution -in other words, for her involvement in the Impossible.

TOMASZ ŁUBIEŃSKI for his lucidity, courage and humor.

MAGDA OCHAŁ for the same things + her exceptional kindness.

ROBERT JAROSZ

for what he himself does not know.

MARCEL ANDINO

for his help.

MARIA MATUSZKIEWICZ for the subtlety of her understanding, and her unfailing commitment.

HER MOTHER, DR JOANNA ROWIŃSKA, DOCTOR PAWEŁ KULICKI, as well as my grandnephew DOCTOR TOMASZ JAXA-CHAMIEC for treating and healing me.

ANIA MOLSKA for the film she never made (about me).

My daughter PAULINA and my grandchildren, TOSIA and ALIK for their presence.

CÉDRIC FAUQ for his open mind and his help.

All the non-indifferent people I may have met during my life.

What does Anka Ptaszkowska do in the art world? She is a critic, an author, a gallery owner and an exhibition organizer -but her work eschews categories defined by art history. Moreover, this trouble agent consciously refuses any form of professionalism. Anka, ceaselessly weaving networks based on friendship, has involved herself with great intensity at the sides of over twenty artists and created more or less temporary alternative venues, such as a gallery or a seminar.

1970 was a pivotal year for her. Since the early sixties -notably as co-founder of the Foksal Gallery -, she had been an active participant of avant-garde art in Poland -at that time, a communist country. Following profound theoretical conflicts, she crossed the Iron Curtain and befriended prominent figures of the French alternative scene. From Warsaw to Paris, there was no break -indeed, backand-forth wanderings and "exchanges" have been a constant theme in a career she always conceived of as free.

In an interview, she explains: "Contradictions attract me so much that the logic of my life (if there is one) becomes legible only as a pathway towards a form of deconstruction." Curating an exhibition about Anka has been a challenge for us, both as researchers and friends. Daniel Buren once advised Anka not to work for but against artists -as for us, we have made our way right up against her, and sometimes, squarely against her.

We have chosen, as a backbone, this thirty-two chapter scenario which was written in a literary and subjective style by Anka in 2016, in preparation for a yet undirected film. On the occasion of the exhibition, this text is published as an artist's book and is meant to guide the public across the exhibition, and to elicit interpretation. In the Capc galleries, our extensive selection includes works personally important to Anka, pieces from her collection and documents culled from her archive. Sounds recordings provide anthropological and sensitive depth to the setting. Other elements of the exhibition bring to light critical nodes pertaining, for instance, to Anka's relationship with politics, power, intimacy and womanhood.


F Dacquait

DEN H Marteau Cea

L Guinard

G Ranchoux

S Taunier

J L Bretelle

A Rocher

THE IMPACT OF STEAM GENERATOR REPLACEMENT ON PWR PRIMARY SYSTEM CONTAMINATION

This paper analyses the impact of Steam Generator Replacement (SGR) on PWR primary circuit contamination. It presents a comparison of the activities deposited inside the primary system and released during refuelling outages after SGR with three different SG tube alloys (600, 690 and 800) and different SG tube manufacturing processes.

A SGR has a great impact on the primary system contamination. After SGR, whatever the SG tube material is, the typical variations are the following:

• The 58 Co contamination increases for 1 to 3 cycles, and then decreases to very low levels in some cases, mainly depending on the manufacturing process of the replacement SG tubes. • The 60 Co contamination tends to decrease on the primary coolant pipes and increases by a lower rate on the new SG tubes.

This analysis highlights the importance on contamination levels after SGR of both the corrosion product deposits on the primary surfaces before SGR and the surface finish of the SG tubes related to their manufacturing process.

1.

INTRODUCTION

In 2000, the previous paper dealing with the impact of Steam Generator Replacement (SGR) on PWR primary system contamination explained that the two main key factors were the corrosion product deposits before SGR and the manufacturing process of the replacement SG tubes [START_REF] Dacquait | Impact of Steam Generator Replacement on PWR Primary Circuit Contamination by Radioactive Corrosion products[END_REF]. Ten years later, the SGR influence on PWR contamination has been reassessed with enriched experimental feedback.

Two radioactive isotopes, 58 Co and 60 Co, contribute by over 90% on the average to the dose rates around primary systems [START_REF] Dacquait | Status of primary system contamination in French PWRs[END_REF]. They come from the activation of nickel and cobalt, according to: 58 Ni (n,p) 58 Co (radioactive half-life: 71 days) and 59 Co (n, γ) 60 Co (radioactive half-life: 5.3 years).

Proceedings of the Nuclear Plant Chemistry Conference 2010, 03-07/10/10, Quebec City (Canada), paper 5.04 NPC 2010 [START_REF] Dacquait | Status of primary system contamination in French PWRs[END_REF] As shown in Figure 1, 58 Co is predominant in dose rates for the first reactor cycles. This figure presents the 58 Co/ 60 Co ratio of primary system surface activity measured by gamma spectrometry using EMECC devices [START_REF] Eimecke | Ensemble de Mesures et d'Etude de la Contamination des Circuits[END_REF] in about 60 different PWRs. The 58 Co and 60 Co contributions to the dose rates are equivalent in the green band. Progressively, the 58 Co contribution decreases giving way to 60 Co, which accumulates due to its longer radioactive half-life. Nevertheless for some PWRs, after several cycles, (red triangles in Figure 1), the 58 Co contribution reaches the level of the first cycles again. This increase is the result of SGR. Because of Inconel 600 Mill-Annealed tube corrosion problems (intergranular attack, stress corrosion cracking ...), PWR steam generators must be replaced. The material and the manufacturing process of the replacement SG tubes vary: namely, Thermally-Treated Inconel 600, Inconel 690TT or Incoloy 800.

Regarding contamination, it is expected that:

• The heat treatment of Inconel should reduce the release [START_REF] Anthoni | Inventory of corrosion product behaviour on EDF's plants[END_REF],

• The higher Chromium content of Inconel 690 (about 29% Cr, 59% Ni, 10% Fe) should reduce the generalized corrosion rate, • The lower Nickel content of Incoloy 800 (about 33% Ni, 21% Cr, 44% Fe) should reduce the 58 Co source.

The impact of these tube materials on contamination is compared and the typical evolutions of 58 Co and 60 Co contamination due to SGR are described and analyzed in the following sections.

DESCRIPTION OF UNITS

In order to study the effect of SGR in the contamination of PWR primary systems, CEA, within the framework of EDF and other operators projects, performed in-situ gamma spectrometry measurements using the EMECC device [START_REF] Eimecke | Ensemble de Mesures et d'Etude de la Contamination des Circuits[END_REF] in 18 PWRs, before and after SGR, both in France and in other countries. Three types of replacement SGs were studied:

• 15 SGRs with alloy 690TT tubes manufactured with different processes,

• 1 SGR with alloy 600TT tubes, NPC 2010

October 3-7, 2010

• 2 SGRs with alloy 800 tubes.

The EMECC measurements lead to an accurate characterization of the contamination levels (surface activity by activated corrosion product) at the time of some refueling outages.

In this paper, we focus on the 5 most representative SGRs. For each of them, Table 1 shows:

• The unit considered.

• The SGR outage (cycle number).

• The year of the SGR outage.

• The alloy of the replacement steam generator tubes. The alloy of the replaced SG tubes in all units was Inconel 600MA. • The steam generator wet surface area before and after SGR. These units are 900 MWe PWRs. For unit D, the power was increased by about 15% after SGR.

The first operating cycle with a coordinated chemistry program at pH 300°C = 7.2 and a maximum lithium concentration of 2.2 ppm was cycle 17 for unit A, cycle 16 for unit B and cycle 14 for units C1 and C2. For the previous cycles, the target pH 300°C was 7.0 with 2.2 ppm maximum lithium.

The manufacturing processes of the Inconel 690TT SG tubes of units B, C1 and C2 differ from the oldest to the most recent respectively.

There was no particular preconditioning at the end of the SGR outage of these units in order to "passivate" the replacement SG tube surfaces

VARIATIONS IN CONTAMINATION

58 Co surface activity

The 58 Co surface activity inside the primary system (hot legs, crossover legs and steam generator tubes at about 2 m above the tubesheet) of units A, B, C1, C2 and D is presented in Figure 2 (primary coolant pipes) and Figure 3 (SG tubes -C: Cold side / H: Hot side).

Whatever the material of the replacement SG tubes (600, 690 or 800) and their manufacturing process are, the 58 Co surface activity generally increases for 1 or 2 cycles inside the primary coolant pipes after SGR (see Figure 2). Afterwards they decrease and, after several cycles, they reach similar levels or even lower levels than those prior to SGR. For the replacement SG tubes, two types of behavior have been observed (see Figure 3):

• The 58 Co surface activity increases for 1 to 3 cycles after SGR and then decreases and reaches similar or lower levels than those recorded prior to SGR (units B, C1, C2 hot side and D); • The 58 Co surface activity seems to increase throughout more than 3 cycles and then stabilizes at levels as high as those prior to SGR (units A and C2 cold side). The high level of 58 Co contamination on the SG cold side of unit C2 was unexpected. The 58 Co surface activity is about 3 times higher than that in unit C1 and similar to unit B and even unit A (see Figure 3). Yet, units C1 and C2 are twin units of a same nuclear power plant and they operate under the same conditions: cycles of 10 to 12 months, coordinated chemistry at pH 300°C = 7.0 until cycle 13 and afterwards at pH 300°C = 7.2. Furthermore, all the fuel assemblies were equipped with Zircaloy grids before SGR and the Inconel 600MA SG tubes were replaced by Inconel 690TT SG tubes. On the other hand, the differences between the two SGRs are the following:

NPC 2010 October 3-7, 2010

• The SGR outage, cycle 11 for unit C1 and cycle 19 for unit C2. Nevertheless, the 58 Co (and 60 Co) contamination had reached equilibrium before SGR in unit C2 and in unit C1 as well. • The SG surface area increased by 14% in unit C2 after SGR whereas the Inconel 690 surface area is the same as Inconel 600 in unit C1. However, the release SG surface area is higher but the deposition SG surface area is as well. • The only identified difference which could explain the high 58 Co level of the cold side SG tubes is the manufacturing process of the Inconel 690TT tubes that has changed between unit C1 and unit C2. Apparently, the SG tube manufacturing process in unit C2 led to a higher corrosion product release than that in unit C1.

The major effect of the SG tube manufacturing process may also be observed before SGR. In Figure 3, we have distinguished the EMECC measurements of SG tubes before SGR as a function of the 600 alloy tube manufacturer "X" or "Y" (e.g. in unit B, the 600 SG tubes of loops 1 & 3 were manufactured by "X" and those of loop 2 by "Y") . For each unit B, C1 and C2, all the SGs obviously were subjected to the same conditions (water chemistry, temperature, fluid velocity…) and yet the SG tubes manufactured by "X" were about 2 to 4 times more contaminated than those manufactured by "Y". The SG tubes manufactured by "Y" released less corrosion products and trapped less contamination [START_REF] Dacquait | Status of primary system contamination in French PWRs[END_REF].

A characteristic of the replacement SG tubes is the fact that the differences in contamination between the hot side (H) and the cold side (C) of the SG tubes are marked in units C1, C2 and D (see Figure 3). The hot side is less contaminated than the cold side, by a factor of 2 to 6. This may be due to a cobalt equilibrium concentration lower at 280°C (cold side) than at 320°C (hot side) in relation with the SG tube oxides. However, the case was the opposite 2 cycles after SGR in unit C2, i.e. the hot side was more contaminated than the cold side (by about +60%). The SG tube oxide structure likely changed during cycles after SGR. This inversion was also observed in other units after SGR. Note that before SGR, there was practically no difference in contamination between the two sides of the SG tube bundles.

Although the replacement SG tube alloy of unit D is Incoloy 800, i.e. with a lower Ni content (about 33% vs. about 59% for Inconel 690), the 58 Co surface activity inside the primary system of unit D is similar or even higher than that observed after SGR with Inconel 690TT, a situation that was unexpected. 14 cycles after SGR, the Incoloy 800 release was still high.

It should be noted that the replacement of Inconel 718 spacer grids with Zircaloy spacer grids from SGR outage in unit A contributed to a reduction of the contamination [START_REF] Anthoni | Origin of Corrosion Products in PWR Primary Circuits[END_REF], as well as for the first refueling outage after SGR in unit B

60 Co surface activity

The 60 Co surface activity inside the primary system (hot legs, crossover legs and steam generator tubes) of units A, B, C1, C2 and D is presented in Figure 4 (primary coolant pipes) and Figure 5 (SG tubes -C : Cold side / H : Hot side).

After SGR, no matter what the type of replacement SG tube alloy used, the 60 Co surface activity tends to decrease or at least remain constant inside the primary coolant pipes (see Figure 4). Such is also the case for the 58 Co contamination (see §3.1), the 60 Co contamination decrease after SGR in units A and B is partly due to the replacement of the Inconel 718 spacer grids by Zircaloy spacer grids. Inside the replacement SG tubes, the 60 Co surface activity increases for several cycles and generally stabilizes at a lower level than that seen prior to SGR, except for the SG cold side tubes of unit D (see Figure 5). Unit D is characterized by a high level of 60 Co contamination, which was already the case before SGR and which was due to an abnormal wear of Stellites or the use of Inconel 718 spacer grids having a large Co content [START_REF] Dacquait | Status of primary system contamination in French PWRs[END_REF]. Such is also the case for 58 Co (see §3.1), the SG hot side is less contaminated by 60 Co than the cold side, particularly in unit D.

Dose rates

The dose rate index of units A, B, C1 and C2 is presented in Figure 6. The dose rate index is an average of dose rates measured at the primary coolant pipes by the operator (hot leg, crossover leg, cold leg of each loop).

Except for unit A, the dose rate index generally increases for 1 or 2 cycles after SGR and then decreases. The high value at SGR outage of unit A shows that a dose rate measured in contact with a primary coolant pipe is not only representative of the actual surface activity of the primary The dose rate variation is primarily due to the variation in the 58 Co surface activity inside the primary coolant pipes (see Figure 2). Thus, the 58 Co contribution to the dose rates around the primary coolant pipes increases after SGR and can be the major one for several cycles to the detriment of the 60 Co contribution as shown in Figure 7. Figure 7 presents the 58 Co and 60 Co average contributions to the dose rates around the primary coolant pipes. Thanks to the MERCURE code [START_REF] Suteau | Improvement of MERCURE-6's General Formalism for Calculating Gamma-Ray Buildup Factors in Multilayer Shields[END_REF], the radionuclide contributions were calculated on contact with the thermal insulations of the primary pipes by using surface activity and component characteristics. Similarly, 58 Co is predominant in dose rates around the SG shells for the first cycles after SGR (see Figure 8). Progressively, the 58 Co contribution decreases giving way to 60 Co, which accumulates due to its radioactive half-life. As for the 58 Co surface activity (see §3.1), the peak 58 Co activity after the primary coolant oxygenation increases for 1 or 2 cycles after SGR and then decreases. Before SGR, the peak 58 Co level due to the primary oxygenation is about 100 GBq/Mg. The first two or three cycles after SGR, it is usually higher than 200 GBq/Mg and it can even reach about 500 GBq/Mg. Note that the shutdown procedure had not changed after SGR for units A, B, C1 and C2 [START_REF] Dacquait | Corrosion Product Transfer in French PWRs during Shutdown[END_REF], and the primary coolant oxygenation occurred before the draining of the reactor coolant system.

Several cycles after SGR in unit A (Inconel 600TT RSG), the peak 58 Co activity remained at rather high levels, about 200 GBq/Mg. In units B, C1, C2 (Inconel 690TT RSG), the peak 58 Co activities reached similar or lower levels than those prior to SGR. In unit B, the peak 58 Co level is similar, about 100 GBq/Mg 14 cycles after SGR, whereas in unit C1, the peak 58 Co level is below 15 GBq/Mg from 7 cycles after SGR and even below 1 GBq/Mg from 9 cycles after SGR.

As for the surface activities (see §3.1), these different types of behavior are attributed to the SG NPC 2010

October 3-7, 2010

tube manufacturing processes which lead to SG tube releases more or less high during operating cycles.

In unit D with Incoloy 800 SG tubes, the peak 58 Co activity was relatively high during several cycles after SGR. It was only from cycle 9 after SGR that the peak 58 Co levels reached values less than about 5 GBq/Mg, as expected for Incoloy 800 SG tubes.

DISCUSSION

Whatever the replacement SG tube alloy used (Inconel 600, Inconel 690 or alloy 800), the 58 Co activities deposited inside the primary systems and released during refueling outages generally increase for 1 to 3 cycles after SGR.

This increase in 58 Co is mainly due to a high Ni release from the replacement SG tubes during the formation of an inner protective oxide layer on the fresh alloy surfaces. Indeed, no special preconditioning was performed to "passivate" the replacement SG tube surfaces during the initial startup after SGR. However, even if a special preconditioning were performed, its impact could be limited [8] or even negative, because the oxides formed during the Hot Functional Test (HFT) passivation procedure could be thermodynamically unstable in the power operating conditions and subsequently dissolved during the first operating cycle after SGR. Tests performed in the CORELE loop [START_REF] Anthoni | CORELE : an out-of-pile loop for corrosion product release measurement from steam generator tubes[END_REF] showed this type of behaviour. Nevertheless, an HFT procedure able to form stable oxides in power operating conditions should reduce the Ni release during the first cycles after SGR.

The circuit cleanliness after a SGR process may also have an impact during the first operating cycles following the SGR outage. Indeed, the SGR process could lead to loose oxide detachments or to an addition of metal dust deposited inside the new tubes. Therefore a complete water purification stage after a SGR process or after an HFT phase is recommended [START_REF] Taunier | Corrosion products behavior and source term reduction : Guidelines and feedback for EDF PWRs, concerning the B/Li coordinations and Steam Generators Replacement[END_REF].

The Ni deposits inside the primary system before SGR should also be considered. During the operating cycles before SGR, Ni released from the Inconel 600MA tubes deposited on the primary surfaces and may dissolve during the cycles after SGR. This "memory" effect decreases with this Nickel reserve.

After the increase in the 58 Co surface and volume activities for 1 to 3 cycles following SGR outage, a decrease in the 58 Co contamination occurs due to a decrease in the Ni release from the replacement SG tubes. The levels reached after several cycles are mainly due to the manufacturing process of the replacement SG tubes. Indeed, the metal release from SG tubes depends on the SG tubing surface finish related to the manufacturing process [START_REF] Carrette | Impact of the Surface State of Steam Generator Tubes on the Release of Corrosion Products in Pressurized Water Reactors[END_REF]. The surface finish is mainly defined by crystallographic, chemical, physicochemical and microgeometric characteristics. At this time, the main parameter controlling the release rate of the corrosion products is not well identified. The levels reached after several cycles do not seem to depend significantly on the SG tube alloy composition because a SGR with alloy 600TT can lead to a 58 Co contamination similar to a SGR with alloy 690TT and the 58 Co surface activity inside Inconel 690TT SG tubes can be similar to the one inside Incoloy 800 SG tubes. This is especially true for a same SG tube alloy, such as in units B, C1 and C2 with Inconel 690TT replacement SG tubes: the differences in contamination are due to different SG tube manufacturing processes and thus to different SG tube surface finishes. For instance, even 14 cycles after SGR, peak 58 Co activity is about 100 GBq/Mg in unit B, whereas it is 100 times lower in unit C1 from 9 cycles after SGR. The Inconel 690TT SG tube manufacturing process NPC 2010 [START_REF] Dacquait | Status of primary system contamination in French PWRs[END_REF] was probably improved between these two SGRs. The SG tubing release in unit C1 is low enough after the formation of the passive oxide layer so that practically all the nickel forms nickel ferrites. There are practically no metallic Ni deposits on fuel rods anymore from 9 cycles after SGR, and therefore the peak 58 Co activity during oxygenation is very low [START_REF] Dacquait | Low primary system contamination levels in some French PWRs[END_REF].

The SG tube manufacturing process changed again between SGRs in units C1 and C2, but this change was not associated to any further improvement of the SG tube release. Note that the higher levels of the surface and volume activities in unit C2 are not due to the higher replacement SG tube surface area (+14%).

The chemistry conditioning, coordinated chemistry at pH 300°C = 7.2 or 7.0, is not responsible for the differences or for the variation in the contamination after SGR. The target pH 300°C was already 7.2 before SGR in unit C2 whereas it was 7.2 after SGR in unit C1 (see §2).

The decrease in the peak 58 Co activity during refueling outages in unit C1 after SGR is also observed in the 58 Co volume activity during operating cycles as shown in Figure 10. This figure presents the average 58 Co volume activity per cycle during operating cycles in units C1 and C2. Even during operating cycles, the level is higher in unit C2 than in unit C1 from the third cycle after SGR. The SG tube manufacturing process also has an impact on the variation in the 60 Co surface activity inside the primary system after SGR. Due to a generally lower Co content of the replacement SG tubes and to the improvement in their manufacturing process, the 60 Co surface activity increases by a lower rate than before SGR inside the new SG tubes and tends to decrease inside the primary coolant pipes. However, due to the long 60 Co radioactive half-life (5.3 years), the contamination levels after SGR mainly result from the actual state existing before SGR.

The variations in the 58 Co and 60 Co contaminations after SGR lead to an increase in the 58 Co contribution to the dose rates around the primary system. 58 Co generally becomes the major contributor to dose rates for the first cycles after SGR then its contribution progressively decreases giving way to 60 Co because, on the one hand, the 58 Co surface activity decreases and, on the other, 60 Co accumulates due to its longer radioactive half-life.

As the steam generator tubes represent the largest primary surface area (about 64% for a 900 MWe PWR), after commissioning and after SGR there is a similitude in the variation in the

CONCLUSION

Given the fact that the steam generator tubes represent the largest primary surface area, a steam generator replacement may greatly impact the primary system contamination. After SGR, whatever the SG tube material is, the typical variations are the following:

• The 58 Co activities deposited inside the primary system and released during refueling outage increase for 1 to 3 cycles and then decrease to very low levels in some cases mainly depending on the material properties of the replacement SG tubes. • The 60 Co surface activity tends to decrease on the primary coolant pipes and to increase by a lower rate on the new SG tubes.

This analysis, based on experimental feedback enriched over the past 10 years, confirms the conclusion of the previous study [START_REF] Dacquait | Impact of Steam Generator Replacement on PWR Primary Circuit Contamination by Radioactive Corrosion products[END_REF]: the two main key factors in the contamination levels after SGR seem to be the corrosion product deposits prior to SGR (especially for the 60 Co contamination) and the surface finish of the replacement SG tubes related to their manufacturing process (impact on the SG tube release and deposit). The SG tube alloy (alloys 600, 690, 800) seems to be of secondary importance.

6.

Figure 1 .

 1 Figure 1. 58 Co/ 60 Co surface activity ratio in PWR primary systems.

Figure 2 .

 2 Figure 2. 58 Co surface activity inside the primary coolant pipes.

Figure 3 .

 3 Figure 3. 58 Co surface activity inside the SG tubes.

Figure 4 .

 4 Figure 4. 60 Co surface activity inside the primary coolant pipes.

Figure 5 .

 5 Figure 5. 60 Co surface activity inside the SG tubes.

Figure 6 .

 6 Figure 6. Dose rate index.

Figure 7 .

 7 Figure 7. 58 Co and 60 Co contributions to the dose rates around the primary coolant pipes.

Figure 8 .Figure 9 .

 89 Figure 8. 58 Co and 60 Co contributions to the dose rates around the SG shells.

Figure 10 .

 10 Figure 10. Average 58 Co volume activity during operating cycles.

  Co total activities deposited on the primary out-of-core surfaces as shown for unit B in Figure11.

Figure 11 .

 11 Figure 11. 58 Co and 60 Co total activities deposited on the primary out-of-core surfaces in unit B.

Table 1 . Description of the SGRs.

 1

	Unit	SGR outage	SGR year	RSG tube alloy	SG wet area Bef./Aft. SGR (m²)
	A	12	1993	600TT	4400/4400
	B	8	1990	690TT	4400/4400
	C1	11	1995	690TT	4400/4400
	C2	19	2003	690TT	4400/5000
	D	11	1993	800	4200/5700