K. Yanagisawa et al., TRANSIENT-BEHAVIOR OF LOW ENRICHED URANIUM SILICIDE PLATE-TYPE FUEL FOR RESEARCH REACTORS DURING REACTIVITY INITIATED ACCIDENT CONDITIONS, Journal of Nuclear Science and Technology, 30(8), 1993, pp. 741-751
This paper describes the results of transient experiments using a low
enriched uranium silicide miniplate fuel for research reactor. The pul
se irradiation was performed in the Nuclear Safety Research Reactor (N
SRR) at the Japan Atomic Energy Research Institute (JAERI). The result
s obtained in this study are summarized as follows : (1) The tested fu
el plates were damaged with energy depositions above 94 cal/g.fuel, bu
t remained intact below 82 cal/g.fuel. A failure threshold should ther
efore exist between these two values. (2) Four of the fuel plates that
showed peak cladding surface temperatures <330-degrees-C were damaged
by the thermal stress during quenching. These damaged fuel plates rev
ealed small intergranular cracks that propagated perpendicularly to th
e axial direction of the plate, from the Al cladding surface to the fu
el core, without significant dimensional changes. On the other hand, w
hen peak cladding surface temperatures were >400-degrees-C, the test f
uel plates were damaged mainly by melting of the Al cladding, accompan
ying significant dimensional changes. (3) The thermal stress of the da
maged fuel plates calculated on the basis of the maximum transient tem
perature drop during quenching was greater than the tensile stress tha
t occurred during fabrication.