Reactor surveillance programmes

J.C. Van Dnysen, J. Bonrgoin, P. Moser and C. Janot, Study of the neutron damage in a PWR pressure vessel steel after long-term irradiations in the Chooz A Reactor Surveillance Programme , Radiation Embrittlement of Nuclear Reactor Pressure Vessel Steels An international review (4th Volume), ASTM STP1170, L.E. Steele, ed., American Society for Testing and Materials, Philadelphia, PA, 1993,132-138. 

Langer R,Backfisch W and Bartsch R (2000), Resnlts and evaluations of irradiation surveillance programmes of Ughtwater reactors in Gevmway , International Journal of Pressure Vessels and Piping, 77, 613-620. 

Typical containers for WWER standard surveillance programmes in WWER-440A/-213 reactor. Dimensions in mm. 

With aluminium clad fuel corrosion issues starting to appear in wet spent fuel storage basins around the world, the IAEA formulated a corrosion surveillance programme in late 1994. This scientific investigation was implemented in 1996 as part of an IAEA Co-ordinated Research Project (CRP) on Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water. Scientists from countries worldwide were invited to participate [1.2]. The results of the CRP were presented at a final research co-ordination meeting (RCM) in Bangkok, Thailand, in October 2000 and are documented in Chapters 5-13. 

The corrosion surveillance programme at SRS, established in 1992, was initiated at a time when corrosion of fuel cladding and aluminium components became evident for the first time. Detailed discussions of the surveillance activities have been presented in Ref. [1.9]. The programme was initially set up to monitor the production fuel and target material from the last irradiation campaigns in the P, K and L Reactors at SRS. The programme was expanded to include the RBOF, in which all the fuel received from off-site locations around the world was stored. 

In the interim period before the new deionization equipment for the L and K basins was received, portable equipment was installed in July 1995 and used to lower the L basin water conductivity from 110 to below 8 pS/cm in 2.5 months. The equipment was then moved to the K basin, and within three months the conductivity was lowered to below 10 pS/cm. Continued deionization in both basins for two more months lowered the conductivity further, to less than 3 pS/cm, and the chlorides, nitrates and sulphates were lowered to about 0.5 ppm. The corrosion surveillance programme continued in the three reactor basins and in the RBOF while the basin and water quality improvements were being carried out, i.e. until mid-1996. Results of the component immersion tests through September 1997 (the last withdrawal) showed no pitting corrosion on any of the corrosion coupons. These coupons were exposed to a variety of conditions for 37-49 months as conditions improved in the basins. Table 1.1 presents a summary of component immersion tests for the period 1992-2000, when corrosion coupons accumulated exposure time in extremely high quahty water and withdrawal intervals were extended. 

Samples of the RBOF water will continue to be analysed on a periodic basis as fuel comes in for interim storage from the FRR sites. This will allow SRS to develop a database on the diversity of the microbiological activity at the different research reactor sites. Corrosion of the spent fuel initiated by any mechanism will continue to be monitored in all basins at SRS through the corrosion surveillance programme. 

KOONEN, E., "BR-2 research reactor modifications experience gained from the BR-2 beryllium matrix replacement and second matrix surveillance programme", Proc. Int. Symp. on Research Reactor Safety, Operations and Modifications, Vol. 3, AECL-9926, Chalk River (1989). 

The spent fuel of Peruvian reactors will be maintained in operational storage until a decision is reached about the disposal option. For this purpose, and in the framework of TC Regional Project RLA/4/018, a spent fuel surveillance programme has been implemented. It includes control of the water chemistry, sipping tests and visual inspection activities. 

Fracture toughness of reactor vessel should be appropriately evaluated and the surveillance programme should be suitably established. The reactor vessel beltline materials shall have sharpy upper-shelf energy, as determined from sharpy V-notch tests on unirradiated specimens of 75ft-lb. The extraction period of surveillance specimen should be in compliance with the requirements of Notice 92-20 of the Ministry of Science and Technology (MOST). 

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