부산대학교 도서관

This paper presents a case study of the temperature fields within and around a six-channel blockage designed as a molten-fuel-release initiator in SLSF-P4, an in-reactor experiment (37-mixed-oxide pin bundle) planned for February, 1981, irradiation. To meet the experiment objectives, a minimum of ten grams of molten UO/sub 2/ must be ejected into the sodium stream from one, two, or three such blockages. The temperature fields of the electrodeposited-nickel blockage filled with a mixture of UO/sub 2/ powder, stainless steel, and gas are found at intervals of full power. The SS content, type of gas, and porosity were parameters varied in this study which used the computer codes THYME-B, SABRE-1, and ANL's version of THTB. State-of-the-art treatments of the conductivity of the mixture and the gas-gap conductance are included. The contrived-blockage design has been found to maintain structural integrity until sufficient molten fuel exists to release, challenge the subassembly, and be detected by delayed-neutron and fission-product monitors. This will serve to resolve lingering questions on rapid pin-to-pin propagation, blockage propagation, and other local-fault issues.