Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Corrosion tests in water of fuel pins irradiated in the world’s first NPP reactor

9/30/2019 2019 - #03 Decommissioning

Ivanov S.N. Porollo S.I. Baranayev Yu.D. Timofeev V.F. Kharizomenov Yu.V.

DOI: https://doi.org/10.26583/npe.2019.3.11

UDC: 621.039.531

Spent nuclear fuel (SNF) storage in reactor spent fuel pools (SFP) is one of the crucial stages of SNF management technology: it requires special measures to ensure nuclear and radiation safety. During long-term storage in water-filled SFPs, leak-tight canisters in which SFAs are usually placed can be depressurized, which will result in the development of corrosion processes in the fuel element claddings. We studied fragments of spent fuel rods of the AM reactor of the World’s First NPP during their long exposure in the aquatic environment. The aim of the study was to obtain experimental data on the corrosion changes in the claddings and fuel composition of fuel rods during the conditioning process as well as on the release of radioactive fission products from them. For the study, a laboratory facility for exposing fuel rods in the aquatic environment was developed and experimental fragments of fuel rods were made. The study was carried out in the hot chamber of the SSC RF-IPPE. The change in the activity of the aquatic environment was estimated by the dose rate of γ-radiation from the selected water sample. The diameter measurements and metallographic studies were carried out in various sections of fuel element fragments.

Corrosion tests were carried out on fragments of spent fuel rods of the AM reactor of the world’s first NPP that were stored for a long time (more than 50 years – fuel rods with U-Mo fuel and ~ 20 years – fuel rods with UO2 fuel) using standard technology – first in SFP canisters filled with water and then in dry canisters in the air. Placing the fuel rods in the aquatic environment did not lead to through damage to the fuel rod claddings and a significant change in the size (diameter) of the outer cladding. Metallographic studies of fuel rod fragments after the corrosion tests showed the presence of intergranular and local frontal corrosion on the surface of the claddings, the depth of which exceeded the depth of the cladding corrosion defects before testing. The rate of radionuclide release from the fuel composition was estimated by the γ-dose rate of water samples taken from glasses with fuel element fragments. Throughout the test period, the radiation dose rate of water samples from glasses with intact fuel rods remained constant. The dose rate from water samples taken from glasses with fragments of fuel elements with an artificial defect grew during conditioning. The results of the study are supposed to be used in the development of spent fuel management technology for the Bilibino NPP which uses fuel analogous to that of the AM reactor fuel.

References

  1. NP-016-05. General Safety Provisions for Nuclear Fuel Cycle Facilities. Available at: https://normativ.kontur.ru/document?moduleId=1&documentId=89086 (accessed Oct 10, 2018) (in Russian).
  2. NP-001-15. General Safety Provisions for Nuclear Power Plants. Available at: https://sudact.ru/law/prikaz-rostekhnadzora-ot-17122015-n-522-ob/np-001-15/ (accessed Oct 10, 2018) (in Russian).
  3. NP-082-07. Nuclear Safety Rules for Reactor Installations of Nuclear Power Plants. Available at: http://gostrf.com/norma_data/52/52470/index.htm (accessed Oct 10, 2018) (in Russian).
  4. NP-091-14. Safety Ensuring in Decommissioning of Nuclear Facilities. General Provisions. Available at: https://meganorm.ru/Index2/1/4293769/4293769639.htm (accessed Oct 10, 2018) (in Russian).
  5. NP-061-05. Safety Rules for Storage and Transportation of Nuclear Fuel at Nuclear Facilities (Available at: https://sudact.ru/law/postanovlenie-rostekhnadzora-ot-30122005-n-23-ob/pravila-bezopasnosti-pri-khranenii-i/ (accessed Oct 10, 2018) (in Russian).
  6. NP-047-03. Nuclear legislation and regulatory documents. Provisions on the Procedure of Investigation and Recording of Events in Operation of Nuclear Fuel Cycle Facilities. Available at: https://sudact.ru/law/prikaz-rostekhnadzora-ot-23122011-n-736-ob/np-047-11/ (accessed Oct 10, 2018) (in Russian).
  7. NP-004-08. Provisions on the Procedure of Investigation and Accounting of Operational Occurrences at Nuclear Power Plants. Available at: https://gostinform.ru/normativnye-dokumenty-po-atomnomu-nadzoru/np-004-08-obj46450.html (accessed Oct 10, 2018) (in Russian).
  8. RB-013-2000. Available at: https://gostinform.ru/normativnye-dokumenty-po-atomnomu-nadzoru/rb-013-2000-obj52891.html (accessed Oct 10, 2018) (in Russian).
  9. NP-002-15. Rules for the Safe Management of Radioactive Waste from Nuclear Power Plants. Available at https://www.seogan.ru/np-002-15-pravila-bezopasnosti-pri-obrashenii-s-radioaktivnimi-otxodami-atomnix-stanciiy.html (accessed Oct 10, 2018) (in Russian).
  10. NP-053-04. Safety Regulations for Transport of Radioactive Materials. Available at https://sudact.ru/law/prikaz-rostekhnadzora-ot-15092016-n-388-ob/np-053-16/ (accessed Oct 10, 2018) (in Russian).
  11. Ivanov S.N., Dvoryshin A.M., Popov V.V., Shulepin S.V. Poost-irradiation Tests of Fuel Assembly and Control Road Channel of the World First NPP. Atomnaya Energiya, 2011, v. 110, no. 2, pp. 17-70 (in Russian).
  12. Ushakov G.N. World First Nuclear Power Plant (construction and operation experience). Moskow-Leningrad. Gosenergoizdat Publ., 1959, pp. 17-19 (in Russian).
  13. Solonin M.I., Ioltukhovsky A.G., Veluhanov V.P., Kadarmetov I.M., Sinelnikov L.P., Timokhin A.N., Golosov O.A., Kuznetsov V.R., Tsykanov V.A., Pavlov S.V., Markov D.V., Smirnov V.P. Material-related Problems of Long Term Dry and Wet Storage of Spent Nuclea Fuel of RBMK-1000. Proc. of the VIth Russian Conference on Reactor Materials, Dimitrovgrad, 11-15 Sept., 2000. Dimitrovgrad. NIIAR Publ., 2000, v. 2, part 2, pp. 3-22 (in Russian).
  14. Volkova I.N., Grin P.I., Kobylyansky G.P., Lyadov G.D., Maershina G.I., Novoselov A.E., Smirnov V.P. State of RBMK-1000 Fuel Pins with E110 Alloy Claddings after Long Wet Storage. Proc. of the VIIth Russian Conference on Reactor Materials, Dimitrovgrad, 08-12 Sept., 2003. Dimitrovgrad. NIIAR Publ., 2003, v. 2, part 1, pp. 258-266 (in Russian).
  15. Sidorenko V.A. Conceptual Aspects of Nuclear Power Development to 2010. Atomnaya Energiya, 1993, v. 76, no. 4, pp. 259-263 (in Russian).
  16. Ivanov S.N., Konobeev Yu.V., Starkov O.V., Porollo S.I., Dvoriashin A.M., Shulepin S.V. Material-related Investigation of Fuel Pins Irradiated in the Reactor of Obninsk NPP after 38 Years Storage. Atomnaya Energiya, 2000, v. 88, n. 3, pp.183-188 (in Russian).
  17. Golosov O.A., Nikolkin V.N., Semerikov V.B., Staritsin S.V., Bedin V.V. Corrosion of Spent Nuclear Fuel of AMB Reactors. Proc. of the Xth Russian Conference on Reactor Materials, Dimitrovgrad, 27-31 May, 2013. Dimitrovgrad. NIIAR Publ., 2013, pp. 253-288 (in Russian).
  18. Golosov O.A., Nikolkin V.N., Lutikova M.S. Fractional Content of Corrosion Products of Spent Nuclear Fuel of AMB Reactors. Proc. of the Xth Russian Conference on Reactor Materials, Dimitrovgrad, 27-31 May, 2013. Dimitrovgrad. NIIAR Publ., 2013, pp. 288-300 (in Russian).
  19. The International Nuclear Event Scale (INES) User’s Manual 2010 Edition Jointly Prepared by IAEA and OECD/NEA International Atomic Energy Agency, Vienna, 2010. Available at: https://howlingpixel.com/i-en/International_Nuclear_Event_Scale (accessed Oct 10, 2018) (in Russian).

fuel pin fuel assembly (FA) spent fuel corrosion tests aquatic environment artificial defect fuel material fission product release metallography γ-dose rate fuel-element claddings Bilibino NPP