Authors & Affiliations

Vilensky O.Yu., Ryabtsov A.V.
Afrikantov Experimental Design Bureau for Mechanical Engineering, Nizhny Novgorod, Russia

Vilensky O.Yu. – Head of Department, Cand. Sci.(Tech.), Afrikantov Experimental Design Bureau for Mechanical Engineering. Contacts: 603074, 15 Burnakovsky proezd, Nizhny Novgorod, Russia. Tel.: +7 (831) 246-97-21; e-mail This email address is being protected from spambots. You need JavaScript enabled to view it..
Ryabtsov A.V. – Deputy Head of Department, Afrikantov Experimental Design Bureau for Mechanical Engineering.

Abstract

During the operation of fuel assemblies in the active zone of fast sodium reactors, a significant degradation of the structural material of fuel assemblies and fuel cladding occurs. As a result, along with a significant change in the basic mechanical properties, the effects of radiation-induced swelling and radiation-induced creep of the materials appear. Radiation shaping of fuel assemblies under conditions of high doses of irradiation with fast neutrons affects the safe operation of the reactor core and leads to the limitation of fuel burnup. Therefore, mathematical models are needed that would most fully reflect the processes occurring in the active zone of fast reactors and are in good agreement with available experimental data. Based on the analysis of the results of the inspected regular and experimental fuel assemblies, the core sleeves of the BN-600 reactor control and protection system, as well as the steel EP-450 samples irradiated in the BR-10 and BN-350 reactors in terms of the radiation swelling rate and the radiation creep modulus obtained depending on the temperature of irradiation, the dose-temperature dependences of these processes are proposed for assemblies of the core of BN reactors made of EP-450 steel. Taking into account the existing dose-temperature dependences of the swelling and creep of the structural materials of the active zones (currently used and promising), mathematical models are recommended for use in calculating the rationale for the radiation formation of assemblies, with the use of the software complex “ANSYS” certified in the Rostechnadzor, expand its capabilities. The computational analysis of the radiation-induced assembly of assemblies, using the presented mathematical models, showed a good agreement between the results obtained with the “ANSYS” software package and the results of post-reactor measurements of the radiation shaping of hexagonal covers of experimental FAs, as well as the sleeves of the BN-600.

Keywords
fuel assembly, radiation shaping, radiation-induced swelling, radiation-induced creep, experimental data, BN-600, cover, EP-450, mathematical model, computational analysis, software complex “ANSYS”

Article Text (PDF, in Russian)

References

UDC 539.3

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2017, issue 3, 3:17