2006 International RERTR Meeting

Abstracts and Available Papers Presented at the Meeting

Characteristics of the WWR-K Reactor Core with Low-Enriched Uranium Dioxide Fuel

F. Arinkin, P. Chakrov, L. Chekushina, Sh. Gizatulin, K. Kadyrzhanov, E. Kartashev,
S. Koltochnik, V. Lukichev, V.Nasonov, N. Romanova, A.Taliev, Zh. Zhotabaev
Kazakhstan Ministry of Energy and Mineral Resources,
The Institute of Nuclear Physics affiliated to the Kazakhstan National Nuclear Center

ABSTRACT

The neutronics and thermal-hydraulic characteristics of the core with eight- and five-tube FAs are presented. The FA face-to face size is 66.3 mm. The net loads of uranium-235 per the eight-tube FA (FA-1) and the five tube FA (FA-2) are ~253 and ~202 g respectively. Five-tube FAs are intended to arrange original channels of the operational elements of the WWR-K CPS. The uranium density of the UO₂-Al fuel meat material is 2.8 g·cm^-3.

The core initial charge is 16 FA-1 and 10 FA-2 (including three AZ shut-down elements, six KO shim elements and the AP automate control element) with the reactivity margin comprising 7.2%Δk/k and the net CPS worthies comprising 9.0%Δk/k (KO and AP) and 2.7%Δk/k (AZ). For the 6-MW power rating, the thermal neutron flux density in the core central channels and in the channels located in the reflector comprise, respectively, ~2.1·10¹⁴ and ~5.0·10¹³ cm^-2·s^-1; the reactor operation cycle reaches 90 days.

Around the core the side beryllium reflector is formed from beryllium pieces step by step, by portions determined by he net efficiency of the shim elements KO and the automate rod (AP). With 24 beryllium pieces (a single row around the core) and the 50-% peak burnup achieved, the net operation cycle duration reaches ~320 days. The thermal neutron flux density in the reflector channels has increased up to 7.2·10¹³ cm^-2·s^-1. The CPS control rod efficiency has increased up to 11.4%Δk/k - for KO and AP, and up to 4.7%Δk/k - for AZ.

Further, as the FAs burnt off are unloaded, beryllium blocks are loaded instead, up to 52 pieces (full occupation of the free core cells). The net efficiency of KO and AR has increased up to 12.4%Δk/k; the thermal neutron flux density in the reflector channels has comprised ~9.3·10¹³ cm^-2·s^-1.
Thermal-hydraulic calculations have proved the core heat-engineering reliability.

 

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