Authors & Affiliations

Adeev V.A.1, Kavun V.O.2, Kavun O.Yu.2
1. Kola NPP, Polyarnye Zori, Russia
2. Scientific and Engineering Centre for Nuclear and Radiation Safety, Moscow, Russia

Adeev V.A. – Head of Laboratory, Cand. Sci. (Tech.), Kola NPP.
Kavun V.O. – Junior Researcher, Scientific and Engineering Centre for Nuclear and Radiation Safety.
Kavun O.Yu. – Head of Laboratory, Dr. Sci. (Tech.), Scientific and Engineering Centre for Nuclear and Radiation Safety. Contacts: bld. 5, 2/8, Malaya Krasnoselskaya st., Moscow, Russia, 107140. Tel.: +7(499)264-05-84; email: This email address is being protected from spambots. You need JavaScript enabled to view it..

Abstract

The Kola NPP continues operating 2nd & 3rd generation fuel featuring higher enrichment of up to 4.87% (FA-2 and FA-3) and an advanced design providing the most optimal performance character-istics. These fuel assemblies are expected to be used in a higher energy density fuel cycle for post-power uprate operation. A fuel loading pattern for operation at an uprated power level involves stricter requirements for power peaking. In addition, a number of bounding core physics parameters must be met.
The present paper provides insights from VVER-440 operation with 2nd and 3rd generation fuels and a brief analysis of power distribution in the reactor core. A comparison of computational and experimental data demonstrated that the difference between the experimental and computational assembly power peaking factors are up to 3% on average. The greatest deviation exceeds a 5%-uncertainty of measurements and calculations for fresh Gd FAs.
Design features of Gd fuel assemblies and their multiplication behaviour were considered contingent on the arrangement of Gd fuel pins in a FA and Gd-containing FAs in the core, as well as adjacent FAs. Ways to produce microconstants are given for coarse mesh diffusion codes, which help address actual operating conditions of fresh FAs.
A description is given of core design techniques that ensure a requisite accuracy to predict power distribution in burnable poison FAs.

Keywords
core design optimization, fuel load, calculation accuracy, power distribution, burnable poison, microconstants, uprated power operation

Article Text (PDF, in Russian)

References

UDC 621.039.5

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2018, issue 1, 1:8