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Discussion on variance reduction technique for shielding

Abstract

As the task of the engineering design activity of the international thermonuclear fusion experimental reactor (ITER), on 316 type stainless steel (SS316) and the compound system of SS316 and water, the shielding experiment using the D-T neutron source of FNS in Japan Atomic Energy Research Institute has been carried out. However, in these analyses, enormous working time and computing time were required for determining the Weight Window parameter. Limitation or complication was felt when the variance reduction by Weight Window method of MCNP code was carried out. For the purpose of avoiding this difficulty, investigation was performed on the effectiveness of the variance reduction by cell importance method. The conditions of calculation in all cases are shown. As the results, the distribution of fractional standard deviation (FSD) related to neutrons and gamma-ray flux in the direction of shield depth is reported. There is the optimal importance change, and when importance was increased at the same rate as that of the attenuation of neutron or gamma-ray flux, the optimal variance reduction can be done. (K.I.)
Authors:
Maekawa, Fujio [1] 
  1. Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
Publication Date:
Mar 01, 1998
Product Type:
Technical Report
Report Number:
JAERI-Review-98-010
Reference Number:
SCA: 700480; PA: JPN-98:006310; EDB-98:081165; SN: 98001981581
Resource Relation:
Other Information: PBD: Mar 1998; Related Information: Is Part Of Use experiences of MCNP in nuclear energy study. 2. Review of variance reduction techniques; Sakurai, Kiyoshi; Yamamoto, Toshihiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [eds.]; PB: 313 p.
Subject:
70 PLASMA PHYSICS AND FUSION; SHIELDING; THERMONUCLEAR REACTORS; NEUTRONS; GAMMA RADIATION; MONTE CARLO METHOD; NEUTRON IMPORTANCE FUNCTION; STAINLESS STEEL-316; COMPUTER CALCULATIONS; ACCURACY; M CODES
OSTI ID:
630027
Research Organizations:
Japan Atomic Energy Research Inst., Tokyo (Japan)
Country of Origin:
Japan
Language:
Japanese
Other Identifying Numbers:
Other: ON: DE98755716; TRN: JP9806310
Availability:
OSTI as DE98755716
Submitting Site:
JPN
Size:
pp. 7-19
Announcement Date:
Aug 18, 1998

Citation Formats

Maekawa, Fujio. Discussion on variance reduction technique for shielding. Japan: N. p., 1998. Web.
Maekawa, Fujio. Discussion on variance reduction technique for shielding. Japan.
Maekawa, Fujio. 1998. "Discussion on variance reduction technique for shielding." Japan.
@misc{etde_630027,
title = {Discussion on variance reduction technique for shielding}
author = {Maekawa, Fujio}
abstractNote = {As the task of the engineering design activity of the international thermonuclear fusion experimental reactor (ITER), on 316 type stainless steel (SS316) and the compound system of SS316 and water, the shielding experiment using the D-T neutron source of FNS in Japan Atomic Energy Research Institute has been carried out. However, in these analyses, enormous working time and computing time were required for determining the Weight Window parameter. Limitation or complication was felt when the variance reduction by Weight Window method of MCNP code was carried out. For the purpose of avoiding this difficulty, investigation was performed on the effectiveness of the variance reduction by cell importance method. The conditions of calculation in all cases are shown. As the results, the distribution of fractional standard deviation (FSD) related to neutrons and gamma-ray flux in the direction of shield depth is reported. There is the optimal importance change, and when importance was increased at the same rate as that of the attenuation of neutron or gamma-ray flux, the optimal variance reduction can be done. (K.I.)}
place = {Japan}
year = {1998}
month = {Mar}
}