Radiation-Induced Degradation of Steel
Study of Radiation-Induced Degradation by Swelling of Austenitic Stainless Steel Intravessel Components in Western PWR and Eastern WWER Reactors
Tech Area / Field
- FIR-MAT/Materials and Materials Conversion/Fission Reactors
3 Approved without Funding
Kurchatov Research Center, Russia, Moscow
- Beloyarsk NPP, Russia, Sverdlovsk reg., Zarechny\nNIKIET (Sverdlovsk Branch), Russia, Sverdlovsk reg., Zarechny
- Pacific Northwest National Laboratory, USA, WA, Richland
Project summaryThe Objective of the Project is the acquisition of experimental data on the values of swelling occurring in austenitic stainless steels being in irradiation conditions typical of intravessel components (IVC) of PWR and WWER type reactors.
In the last years the data appeared indicating the existence of new important and potentially dangerous from viewpoint of PWR and WWER safety problems [1-5]. It was believed earlier, that for austenitic stainless steels, applied in reactors of these types, there are no problems connected with void swelling and related steel property degradation. But the data obtained recently testify that this point of view is incorrect and IVC of PWR and WWER type reactors, made from austenitic stainless steels, can be the subject to void swelling during operation.
At the moment, this problem emerges as one of most important for nuclear safety of PWR and WWER type reactors that becomes evident all over the world. In 1997 it was officially acknowledged in the documents of MINATOM, Russia.
Technical Approach includes:
1. Acquisition of experimental data which should allow to expand the range (relative to the existing range of irradiation conditions for Р/С during projected lifetime) of irradiation conditions, for which the values of swelling occurring in austenitic stainless steels are known. These data should be extracted as a result of examination of austenitic stainless steels irradiated in PWR and WWER type reactors in conditions characteristic of their operation and in contact with water coolant.
2. Acquisition of experimental data on influence of fast neutron flux density (during irradiation in breeder reactors) on the values of swelling occurring in austenitic stainless steels.
3. Acquisition of experimental data on swelling occurring in austenitic stainless steels as a result of irradiation in PWR and WWER type reactors at fast neutron flux densities overlapping with the lower boundary of the range of neutron fluxes in breeder reactors.
4. Evaluation of reliability of the predicted values of swelling occurring in IVC materials for PWR and WWER type reactors with the use of data on irradiation of austenitic stainless steels in breeder reactors. Such evaluation should involve the sum total of available experimental data.
Fulfillment of the project would allow achieving the following results:
1) in the field of scientific activity:
- experimental data on peculiarities of radiation swelling occurring in austenitic stainless steels irradiated in thermal neutron and breeder reactors would be obtained;
- the role of hydrogen and helium in swelling of austenitic stainless steels irradiated in PWR and WWER type reactors would be revealed;
- availability of prediction of IVC behavior in reactors of PWR and WWER type during their operation from data on testing of materials irradiated in thermal neutron and breeder reactors would be evaluated.
2) in the field of economical activity:
- complicated radiation material researches would be accomplished with the materials used in devices of nuclear reactors that are essential for the safety of those reactors. These studies are planned so that expensive irradiation experiments are not involved. This is possible due to the fact that the materials irradiated earlier in different parts of nuclear reactors would be studied. It permits to reduce significantly the charges needed for realization of the project.
3) in the field of industry:
- experimental data on behavior of austenitic stainless steels during irradiation that would be obtained in the course of realization of the project can be used to maintain predictions of IVC behavior in PWR and WWER type reactors and increase the safety of their operation in the countries - participants of the project.
As a whole, fulfillment of the submitted project would allow to increase reliability of substantiation of radiation lifetime and safety of PWR and WWER type reactors.
The potential role of western participants in the present project would consist in complement of the range of the materials and irradiation conditions leading to increase in confidence level of predicted for IVC materials behavior in PWR and WWER type reactors.
1. B.A.Gurovich, V.G.Kapinos, S.I.Golubov et.al. "Analiz radiatsionnykh povrezhdeniy v austenitnykh nerzhaveyushchykh stalyakh i splavakh obluchennykh neitronami v oblasti temperatur nachala poroobrazovaniya", Preprint IAE -5029/11, Moscow, 1990.
2. F.A. Gamer, L.R. Greenwood, and D.L. Harrod, Sixth International Symposium on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, the Minerals, Metals and Materials Society, (1993) 783-790.
3. F.A. Garner, Transactions of the American Nuclear Society, 71 (1994) 190-191.
4. F.A. Garner, M.B. Toloczko, S.I. Porollo, AN. Vorobjev, A.M. Dvoriashin, and Yu. V. Konobeev, Eighth International Symposium on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, August 10-14, 1997, Amelia Island, Florida, in press.
5. F.A. Garner, Materials Science and Technology: A Comprehensive Treatment, Vol 10A, VCH Publishers, (1994) 419-543.
6. M.L. Hamilton, F.S. Huang, W.J.S.Yang, and F.A. Garner, 13th International Symposium on Effects of Radiation on Materials, ASTM STP 956, (1987) 2450270.
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