Phenix operating experience

Reactor core. The reactor block is of an integrated design (pool) except for a few auxiliary circuits. The entire primary sodium system, containing 800 tons of radioactive sodium, is enclosed in the main reactor vessel, which is 11.8 m in diameter (Fig. 2.10). 

The fissile core, in which most of the reactor power is generated, is surrounded by a fertile blanket and neutron shielding to prevent activation of the secondary sodium flowing through the intermediate exchangers. 

The fuel is uranium dioxide mixed with plutonium dioxide (U02 - Pu02). It is contained in 103 subassemblies, each containing 217 pins, which in turn consist of a stack of sintered oxide pellets, S.S mm in diameter, in stainless steel cladding. The pins are assembled in clusters in a stainless steel outer shell, which also contains the upper and lower fertile blanket pins (depleted uranium oxide) and the upper neutron shielding. 

The radial blanket is composed of depleted uranium dioxide pellets measuring 12.15 mm in diameter, in 90 assemblies of 61 pins each. The structural components of these subassemblies are identical with those of the fissile subassemblies, with sodium flow through the spike inserted into the diagrid. 

Vessel. The sodium in the main vessel is separated into two zones  

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Coulon, P.. Martin, L., Phenix Operating Experience Fuel Management and Fuel Cycle. Ibid. 

Serious loss of generation and increased expenses were caused by the need to repair all the IHXs and then replace some of them. The removal, washing and decontamination of an IHX was a very difficult maintenance task. It was pointed out by the TCM participants that IHX operational experience, except for Phenix, is excellent. 

The comprehensive operational experience with LMFRs BN-350, Phenix, PFR, BN-600, Superphenix and Monju has shown that, if plant components have been designed and manufactured without errors and representative specimens or models have been tested prior to installation, reliable operation can be ensured during the whole operational life. 

J.L. Carbonner, A. Lapicore, "Ten years operating experience with the large components of the Phenix plant", Proc. of FBRs - Experience and Trends, Vol 2, Lyons, France, 22-26 July 1985. 

Operational experience gained on LMFRs, such as BN-350, Phenix, PFR, BN-600 etc. has proved, that sodium is practically non-corrosive to stainless steel, and content of impurities, mainly oxygen and carbon, are maintained at acceptably low level by the cold traps installed in the bypass of the main coolant circuit. Radioactive hazardous isotopes (caesium, tritium, strontium and iodine) are retained by sodium. 

A vast modernization programme at the Phenix nuclear power plant has been undertaken. The works which have been performed or which are currently underway account for approximately 3 million hours. Power operation is scheduled to resume at the end of 2002. The reactor then will be able to carry out the irradiation experiments in order to provide answers on the subject of the future of nuclear waste. Furthermore, it will contribute to the acquisition of fast reactor operating experience. 

Activities on LMFR technology have been conducted in France in close cooperation with Western European Countries. Status of technology development in 1994 and future R D are described in this paper. The paper also presents some performance results and gives an overview of the European Fast Reactor, the CAPRA project and knowledge acquisition programmes as well as the Phenix and Superphenix reactors restart and operation experience. 

ELIE, X., CHAUMONT, J.M., Operation experience with the Phenix prototype fast reactor, Proc. Int. Conf, Kyoto, Vol. 1 (1991) pp. 5.1-1-5.1-10. 

SUPER PHENIX 1 OPERATING EXPERIENCE 2.4.1. Design features... 

Elie, X., Chaumont, J.M., Operation Experience with the Phenix Prototype Fast Reactor. Ibid. 

Chapter 2 details operating experience from the world s prototype and demonstration fast reactors, BN-350 and BN-600 in the former Soviet Union, Phenix and Super Phenix in France, and PFR in the United Kingdom. Smaller test reactors such as FBTR, JOYO, BOR-60, EBR-II, FFTF and Rapsodie are not covered. Chapter 3 describes pre-operational testing of SNR-300 and MONJU. Between them these two chapters give a complete account of the decade s technical progress on fast reactors of greater than 250 MW(e) capacity. 

The PHENIX Life Extension Project groups together all the actions required to pursue operation of the reactor, particularly with a view to performing irradiation experiments in the framework of the back-end of the fuel cycle programs. As such, it comprises a series of investigations whose objective is to assess the state of the reactor after about one hundred thousand hours of operation. 

Commercial introduction of fast breeder reactors in France has been postponed however, alternative LMFR application is being developed, namely transmutation of long-lived nuclear waste and utilization of plutonium. Continued operation of Phenix at 350 MW(th) is related to these requirements. One of the objectives of expanding the lifetime of the Phenix reactor is to perform the necessary irradiation experiments in support of the project identified as "Concept of Intensive Plutonium Reduction in Advanced LMFR. 

Exchange detailed technical information on fast reactor operation and/or decommissioning experience with DFR, PFR (UK) KNK-II (Germany) Rapsodie, Phenix, Superphenix (France) BR-10, BOR-60, BN-600 (Russian Federation) BN-350 (Kazakhstan) SEFOR, EBR-II, Fermi, FFTF (USA) FTBR (India) JOYO, MONJU (Japan) ... 

The choice of the carbonation operation is based on experience feedback from secondary pipework treatment operations for inspection and carbonation of the SPX irradiated assemblies storage tank on the Phenix power station at the time of its dismantling. The carbonation of the pipework residual sodium therefore constitutes the reference solution for the treatment of secondary and auxiliary SPX circuits. However, it was decided to engage a demonstration site for treatment of an auxiliary circuit by the carbonation process. The selected auxiliary circuit has been in a so-called fossil condition since 1992. Today, this circuit has been partly dismantled and comprises several parts drained and maintained under inert gas. It consists of two identical and independent loops whose main characteristics are as follows ... 

The start-up and operation of the Na-cooled fast reactors Phenix and Superphenix has provided a large amount of valuable experience, as the decommissioning of Superphenix is doing right now. We shall focus here on the feedback of the neutron physics experiments performed in both reactors on the neutron physics calculation tools and methods. 

In 2000, it has been decided to create an everlasting data base of documentation with easy access for consulting, in order to keep knowledge an experience acquired through the development, design, construction and operation of the French LMFR plants (RAPSODIE, Phenix, Superphenix, and EFR projects). 

Excluding military and space reactors, approximately 20 sodium-cooled fast reactors have been built in a variety of sizes and configurations. These vary from small test reactors to the French Super-Phenix plant, which had an output of 1240 MW(e). In the United States, several fast reactors were built. These included the EBR-II and the Fast-Flux Test Facility (FFTF)—a 400-MW(t) reactor. The Clinch River Breeder Reactor Plant (CRBRP), a commercial demonstration reactor, was designed and partly built before being cancelled. These machines provide a large experience base in refueling operations (Romrell et al., 1989 Althaus and Brahy, 1987). 

The experience acquired in the operation of sodium circuits having dimensions similar to those found on the Super-Phenix reactor constitutes a fundamental source of information concerning several points ... 

Then, Enrope came to the forefront. The UK constructed and operated PFR, the first prototype FR in Europe, following DFR. Now, the PFR has finished its roles and is in the process of decommissioning. Meanwhile, France constmcted and operated a demonstration reactor Snperphenix based on the experience of constmction and operation of Rapsodie and Phenix, bnt it is closed. 

The Rapsodie experimental sodium cooled reactor was the first French fast neutron reactor. The construction was started in 1962 within an association of CEA and EURATOM. The reactor went critical on 28 January 1967, reaching 20 MW (th) power on 17 March 1967. The core and equipment were modified in 1970 to increase the thermal power level to 40 MW (th). The operating parameters were similar to those in large commercial size reactors. During 16 yets of operation 30 000 fill pins of the driver core were irradiated, of which -10 000 reached a bumup beyond 10% 300 irradiation experiments and more than 1 000 tests have been performed. The maximum bumup of the test fuel pins was 27% (173 displacement per atom). In 1971, the irradiations performed in the core revealed a phenomenon of irradiation swelling in the stainless steel of the wrapper and the fuel cladding in the high neutron flux. The R sodie results have been extrapolated in the Phenix reactor. 

MARTIN, L., et al.. Life extension of Phenix NPP, paper presented at the IAEA meeting on Operational and decommissioning experience with fast reactors, 11-15 March 2002, Cadarache, France. 

But this incident also led the Safety Authorities to demand, at the end of October 1990, a general re-examination of the organization of plant operation and further safety studies, in particular of the sodium fire risk in the secondary galleries, and feedback of experience from the Phenix incident. 

The AGT 8 is concerned with exchanging experience arising from the operation of European fast reactors, namely PHENIX, SUPERPHENIX, PER and KNKII. Analysing and comparing the in-service behaviour of the equipment, and the lessons gained from maintenance or repair works of main components, are particularly valuable. 

Reactor safety experience has been good and sodium-cooled fast reactors have continued to give particularly low radiation doses to operating personnel and low releases of radioactive material to the environment, even in the cases of the sodium fires mentioned above. Safety has been examined closely by the licensing authorities in some countries, in all cases with satisfactory results. Super Phenix was subjected to a major public safety review, which made a positive recommendation. PFR was licensed to modem safety standards applicable to commercial thermal reactor plants. The EFR design has been reviewed and shown to meet safety standards comparable with those of future PWRs. 

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