Abstracts and Available Papers Presented at the
2000 International RERTR Meeting

CHARACTERISTIC TESTS OF SILICIDE FUEL CORE IN JRR-3M

Masahiro YAGI, Shigeru WADA,
Yoji MURAYAMA and Mitsuo TAKEUCHI

JRR-3 Operation Division, Department of Research Reactor
Japan Atomic Energy Research Institute
Tokai-mura Naka-gun Ibaraki-ken 319-1195, Japan

ABSTRACT

In JRR-3M, the core conversion works from the aluminide fuel to the silicide fuel had been conducted since September of 1999. In the core and the heavy water tank, four BF₃ counters and two CICs were installed so as to measure a small amount of neutron, and antimony was installed in the beryllium reflector as the neutron source. JRR-3M achieved the first criticality using the silicide fuels on September 17th, 1999. The minimum critical core was achieved with 15 standard fuel elements. The minimum critical mass was measured to 8.467 kg ²³⁵U. This result of measurement agreed approximately with the result of calculation with the MVP code. After that, JRR-3M constituted the full core. As the result, the excess reactivity in JRR-3M core was measured to 14.1 %Dk/k. Beside, the neutron flux, the control rod reactivity worth, the heavy water dump effecting, the moderator temperature effecting and so on had been measured as the characteristic test with the core conversion. Several reactor physics parameters had been obtained by these tests.

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