"TITLE","AUTHORS","SUBJECT","SUBJECT_RELATED","DESCRIPTION","PUBLISHER","AVAILABILITY","RESEARCH_ORG","SPONSORING_ORG","PUBLICATION_COUNTRY","PUBLICATION_DATE","LANGUAGE","RESOURCE_TYPE","TYPE_QUALIFIER","RELATION","COVERAGE","FORMAT","IDENTIFIER","REPORT_NUMBER","DOE_CONTRACT_NUMBER","OTHER_IDENTIFIER","DOI","RIGHTS","ENTRY_DATE","OSTI_IDENTIFIER","PURL_URL"
"Effects of UO{sub 2}-fuel grain size on reactivity. Continuous energy Monte Carlo calculations","Sakurai, Yoshinori [Kyoto Univ. (Japan)]; Okuno, Hiroshi; Naito, Yoshitaka","22 GENERAL STUDIES OF NUCLEAR REACTORS; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; FUEL CELLS; REACTIVITY; URANIUM DIOXIDE; MONTE CARLO METHOD; HETEROGENEOUS EFFECTS; WATER; MULTIPLICATION FACTORS; RESONANCE ESCAPE PROBABILITY; PARTICLE SIZE; CRITICALITY; 220300; 050700; FUEL ELEMENTS; FUELS PRODUCTION AND PROPERTIES","","Heterogeneity effects on reactivity of powdered or slurry fuel were studied through criticality calculations of three-dimensional tiny cells, which were infinitely arrayed and consisted of a spherical fuel pellet of 5 wt% {sup 235}U-enriched uranium dioxide surrounded by water; the diameter of the fuel pellet was varied from 0 (homogeneous) to 6 mm, keeping constant the volume ratio of water to fuel. Reaction rates were calculated by solving the continuous energy transport equations by the Monte Carlo method. The infinite-medium multiplication factor and its four-factors, and their fractional changes from the homogeneous system were obtained. The infinite-medium multiplication factor increased when the system changed from homogeneous to heterogeneous. The results of calculations confirmed that the reactivity increase mainly came from the resonance escape probability p; they also indicated that any uranium-fuel system of grain size less than 100 {mu}m could be treated homogeneous if a 0.3 % increment of reactivity was regarded small enough to be negligible. (author).","","OSTI; NTIS (US Sales Only); INIS","Japan Atomic Energy Research Inst., Tokyo (Japan)","","Japan","1991-09-01","Japanese","Technical Report","","Other Information: PBD: Sep 1991","","Medium: X; Size: 40 p.","ON: DE92768017","JAERI-M-91-137","","Other: ON: DE92768017; TRN: JP9112095","","","2008-02-12","10117378",""