Title: Transient behaviour of low-enriched uranium silicide plate-type fuel for research reactors during a reactivity-initiated accident

Authors: Kazuaki Yanagisawa

Addresses: Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma, 370–1292, Japan

Abstract: In many research reactors and test reactors, a low enriched (<20 wt% 235U) silicide fuel is to be used in the replacement of a high (93wt% 235U) to medium (45wt% 235U) enrichment aluminide fuel because a peaceful use of nuclear energy. At the Nuclear Safety Research Reactor (NSRR), the pulse irradiation tests were conducted on silicide mini-plate fuels to study the fuel reliability under transient temperature conditions. In the study energy deposition ranged from 32 to 164 cal/g • fuel plate. The given energies were corresponded to the peak cladding surface temperatures ranged from 140°C to 970°C. The major findings from the study are: (1) neither failure nor degradation of dimensional stability of the tested silicide mini-plate fuel occurred in the temperature below 174°C (TDNB; departure from nucleate boiling temperature). Above temperatures of TDNB, the dimensional stability was gradually degraded with temperature; (2) the tested silicide mini-plate fuels were intact at energy depositions <82 cal/g • fuel plate but were damaged at energy depositions of >94 cal/g • fuel plate. A failure threshold must be existed between these two values.

Keywords: transient behaviour; low-enriched silicide fuel; research reactors; reactivity initiated accidents; failure threshold; uranium silicide; nuclear accidents; nuclear safety; pulse irradiation tests; nuclear power; nuclear energy.

DOI: 10.1504/IJNEST.2008.020534

International Journal of Nuclear Energy Science and Technology, 2008 Vol.4 No.2, pp.97 - 110

Published online: 29 Sep 2008 *

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