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Tanigawa, Masafumi; Seya, Kazuhito*; Asakawa, Naoya*; Hayashi, Hiroyuki*; Horigome, Kazushi; Mukai, Yasunobu; Kitao, Takahiko; Nakamura, Hironobu; Henzlova, D.*; Swinhoe, M. T.*; et al.
JAEA-Technology 2024-014, 63 Pages, 2025/02
JAEA-Technology-2024-014.pdf:3.02MB
The liquid waste treatment process generated sludge items at the plutonium conversion development facility. They are highly heterogeneous and contain large amounts of impurities (Na, Fe, Ni etc.). Therefore, the sludge items have very large sampling uncertainty and so the total measurement uncertainty is very large (approximately 24%). The plutonium scrap multiplicity counter (PSMC) measurement technique for sludge items was developed by joint research between the Japan Atomic Energy Agency (JAEA) and Los Alamos National Laboratory (LANL). The technical validity for sludge items using the PSMC was evaluated using various types of sample measurements and Monte Carlo N-Particle transport code calculations. The PSMC measurement parameters were found to be valid for use with sludge items and the validity of multiplicity analysis was confirmed and demonstrated through comparisons with standard MOX powder and a standard sludge. As a result, the PSMC measurement values were shown to be consistent and reasonable and the large amount of impurity (Fe, Ni etc.) did not impact the results. Therefore, the measurement uncertainty of the improved nuclear material accountancy (NMA) procedure by combined PSMC and high-resolution gamma spectrometry was shown to be 6.5%. In addition, an acceptance test was conducted using PSMC/HRGS and IAEA benchmark equipment. Measured Pu mass by both equipment agrees within the measurement uncertainty of each method, and so the validity for Pu mass measurement by PSMC/HRGS was confirmed. The above results confirm the applicability of PSMC/HRGS as an additional NMA method for sludge and a newly designed NDA procedure based on this study is applied to sludge for NMA in PCDF.
-rays from slow neutron-induced fission of 
U with STEFFWright, T.*; Harada, Hideo; Kimura, Atsushi; 121 of others*
European Physical Journal A, 60(3), p.70_1 - 70_11, 2024/03
Times Cited Count：0 Percentile：0.00(Physics, Nuclear)Konno, Chikara
Journal of Nuclear Science and Technology, 61(1), p.121 - 126, 2024/01
Times Cited Count：3 Percentile：39.40(Nuclear Science & Technology)The JENDL-4.0/HE neutron and proton ACE files were produced in 2017 and those of 22 nuclei for neutron and 25 nuclei for proton were bundled in the PHITS code. Recently it was found that the following five data in the JENDL-4.0/HE neutron and proton ACE files had any problems; ACE files for 
N and 
O, heating numbers, damage energy production cross sections, secondary neutron multiplicities and fission cross sections. Thus new JENDL-4.0/HE neutron and proton ACE files were produced with the problems fixed. This paper describes the problems and how to produce the new neutron and proton ACE files in detail.
Iwamoto, Hiroki; Meigo, Shinichiro
Journal of Nuclear Science and Technology, 57(3), p.276 - 290, 2020/03
Times Cited Count：2 Percentile：14.01(Nuclear Science & Technology)This paper presents an approach to uncertainty estimation of spallation particle multiplicity of lead (
Pb), primarily focusing on proton-induced spallation neutron multiplicity (
) and its propagation to a neutron energy spectrum. The uncertainty is estimated from experimental proton-induced neutron-production double-differential cross sections (DDXs) and model calculations with the Particle and Heavy Ion Transport code System (PHITS). Uncertainties in multiplicities for 
, 
, and 
reactions are then inferred from the estimated uncertainty and the PHITS calculation. Using these uncertainties, uncertainty in a neutron energy spectrum produced from a thick Pb target bombarded with 500 MeV proton beams, measured in a previous experiment, is quantified by a random sampling technique, and propagation to the neutron energy spectrum is examined. Relatively large uncertainty intervals (UIs) were observed outside the lower limit of the measurement range, which is prominent in the backward directions. Our findings suggest that a reliable assessment of spallation neutron energy spectra requires systematic DDX experiments for detector angles and incident energies below 100 MeV as well as neutron energy spectrum measurements at lower energies below 
1.4 MeV with an accuracy below the quantified UIs.
Hosoma, Takashi
JAEA-Research 2016-019, 53 Pages, 2017/01
JAEA-Research-2016-019.pdf:5.71MB
Application of probability generating function for nondestructive nuclear materials assay system was studied. First, high-order neutron correlations were derived algebraically up to septuplet and basic characteristics of the correlations were investigated. It was found that higher-order correlation increases rapidly in response to the increase of leakage multiplication, crosses and leaves lower-order correlations behind, when leakage multiplication is 
1.3 that depends on detector efficiency and counter setting. Next, fission rates and doubles count rates by fast neutron and by thermal neutron in their coexisting system were derived algebraically. It was found that the number of induced fissions per unit time by fast neutron and by thermal neutron, the number of induced fissions (
1) by one source neutron, and individual doubles count rates were possible to be estimated from Rossi-alpha combined distribution and measured ratio of each area obtained by differential die-away self-interrogation and conventional assay data.
Hosoma, Takashi
JAEA-Research 2015-009, 162 Pages, 2015/08
JAEA-Research-2015-009.pdf:22.3MB
Neutron coincidence counting assay systems have been developed in the last two decades. Objects would extend to high-mass uranium-plutonium dioxide containing other spontaneous fission nuclei, so essentials of neutron multiplicity counting were reconsidered and expanded: (a) Formulae of multiplicity distribution were algebraically derived up to septuplet using a probability generating function; (b) Leakage multiplication was evaluated not by Monte Carlo method but by an average length from an arbitrary point inside a sample to an arbitrary point on its surface and a probability of induced fission within the length; (c) Mechanism of coincidence counting was associated with a couple of different time axes in Poisson process, and consequently a pair of close-to-coincident neutrons from the process was derived. For the formulae, new expressions using combination were wrote down. For spectrum and mean free path, actually treated uranium-plutonium dioxide was selected as an example.
Okajima, Shigeaki; Yamane, Yoshihiro*; Takemoto, Yoshinari*; Sakurai, Takeshi
Journal of Nuclear Science and Technology, 37(8), p.720 - 723, 2000/08
no abstracts in English
Ikezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; ; B.J.Qi*; H.J.Kim*; Iwamoto, Akira; et al.
Physical Review C, 46(5), p.1922 - 1933, 1992/11
Times Cited Count：45 Percentile：89.50(Physics, Nuclear)no abstracts in English
H and 
He emissions in 
O + 
Au reactionIkezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; Iwamoto, Akira; Otsuki, Tsutomu*
Physical Review C, 42(4), p.1187 - 1190, 1990/10
Times Cited Count：16 Percentile：60.24(Physics, Nuclear)no abstracts in English
He multiplicity in the 
F + Au reactionIkezoe, Hiroshi; Shikazono, Naomoto; Nagame, Yuichiro; Sugiyama, Yasuharu; Tomita, Yoshiaki; Ideno, K.; Iwamoto, Akira;
Physical Review C, 42(1), p.342 - 353, 1990/07
Times Cited Count：35 Percentile：85.83(Physics, Nuclear)no abstracts in English
