DOI: 10.55176/2414-1038-2021-4-35-46
Authors & Affiliations
Likhanskii V.V.1,2, Sorokin A.A.1,2, Zborovskii V.G.2, Ulibyshev K.E.1, Strozhuk A.V.3
1 National Research Center “Kurchatov Institute”, Moscow, Russia
2 P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia
3 JSC “State Scientific Center – Research Institute of Atomic Reactors”, Dimitrovgrad, Russia
 
 
Likhanskii V.V.1,2 – Head of Department, Dr. Sci. (Phys.-Math.). 
  Sorokin A.A.1,2 – Head of Laboratory, Cand. Sci. (Phys.-Math.). Contacts:  23, Oktyabrsky prospect, apt. 60, Moscow, 108841, Russia. Tel. +7 (916) 239-41-84; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
  Ulibyshev K.E.1 – Senior  Researcher, Cand. Sci. (Phys.-Math.).
  Zborovskii V.G.2 – Senior  Researcher, Cand. Sci. (Phys.-Math.).
  Strozhuk A.V.3 – Head of  Laboratory.
Abstract
The paper presents a  description of the RTOP-CA code models designed for simulating the behavior of  (U, Gd)O2 fuel rods, presents the examples of  program verification using experimental data obtained at the research reactor  in Halden and in the post-irradiation examinations of WWER fuel. The experience  of operating WWER fuel has shown that differences in the thermomechanical  behavior of (U, Gd)O2 fuel elements and UO2 fuel  rods during the first – second fuel cycles can be observed. In particular, an  accelerated increase in the length of the (U, Gd)O2  fuel rod cladding as compared to UO2 fuel elements is possible. To  simulate the behavior of (U, Gd)O2 fuel rods under  irradiation in the RTOP-CA code, models that describe the features of  uranium-gadolinium fuel were developed.
  To calculate the  evolution of heat release in (U, Gd)O2 fuel rods in  the RTOP-CA code, a model of burnup of gadolinium isotopes was implemented. The  developed model makes it possible, without using of detailed neutron-physical  calculations, to simulate the burnup of gadolinium and the evolution of heat  generation along the radius of the pellets. The models take into account the  effect of the gadolinium oxide content on the thermophysical and mechanical  properties of the fuel. The calculations performed using the RTOP-CA code are  in good agreement with the results obtained during the experiments in Halden on  the dynamics of the central fuel temperature, gas pressure in the (U, Gd)O2  fuel rod, and the elongation of the fuel column and cladding. To simulate the  accelerated elongation of (U, Gd)O2 fuel rods in  comparison with standard WWER fuel elements at the initial stages of fuel  operation at nuclear power plants in the RTOP-CA code, a model of mechanical  interaction of pellets and cladding was developed taking into account the  misaligned arrangement of pellets.
Keywords
RTOP-CA code, simulation of nuclear fuel behavior,  (U, Gd)O2 fuel, 155Gd, 157Gd burn-up,  thermos-mechanical behavior of fuel rods, cladding elongation in (U, Gd)O2  fuel rods, difference  in lehgth of UO2 and (U, Gd)O2 fuel rods, incompact  mechanical contact
Article Text (PDF, in Russian)
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UDC 621.039.548
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2021, issue 4, 4:4