Abstract

In response to the nuclear material accounting and control system, uranium or plutonium mass and also the isotope abundance should be quantified comprehensively. Commonly, in nuclear safeguards and nuclear security field, active mode is most reasonable for nuclides with low spontaneous rates like uranium measuring for neutron accounting equipment. The spatial detection efficiency and the number of induced fission neutrons are researched in the paper by Monte Carlo simulation and laboratory experiments. A geometric model is built for Monte Carlo simulation to symbolize the measurement of neutrons. The data are assayed with the fission time randomly generated by matlab that conforms to the Poisson distribution to obtain the neutron pulse sequence. The multiplicity shift register (MSR) simulation program performs statistical analysis on the neutron pulse sequence to obtain the corresponding count rates. After that, U3O8 standard source was placed at more than 50 positions, and the comprehensive simulations were conducted. Spatial detection efficiency is practically consistent in the measurement cavity, which proves that the main influencing factors of the neutron measurement results are the spatial distribution of the induction source and the sample. The spatial distribution curves obtained in the fitting results can be used to correct the spatial effect of neutron measurement in the active mode of this device and provide a reference for the subsequent optimization of active neutron measurement equipment and the application of different measurement scenarios.

Issue Section:
Technical Briefs
Keywords:
uranium material, active neutron counting, Monte Carlo simulation
Topics:
Neutrons, Nuclear fission, Simulation, Cavities, Fittings

References

1.
Reilly
,
D.
,
Ensslin
,
N.
,
Smith
,
H.
, and
Kreiner
,
S.
,
1991
, “
Passive Nondestructive Assay of Nuclear Materials
,” LANL, Los Alamos County, NM, Report No. LA-UR-90-732.
2.
Ensslin
,
N.
,
Geist
,
W. H.
,
Krick
,
M. S.
, and
Pickrell
,
M. M.
,
2007
, “
Active Neutron Multiplicity Counting
,” LANL, Los Alamos County, NM, Report No. LA-UR-07-1403.
3.
Hendricks
,
J. S.
,
Swinhoe
,
M. T.
, and
Favalli
,
A.
,
2022
,
Monte Carlo N-Particle Simulations for Nuclear Detection and Safeguards: An Examples-Based Guide for Students and Practitioners
,
Springer Nature
,
Cham, Switzerland
.
Google Scholar
Crossref
Search ADS
 
4.
Zhongjie
,
W.
,
Quanhu
,
Z.
,
Jie
,
L.
, and
Cailu
,
G.
,
2010
, “
Designing of the 3He Detector in Neutron Multiplicity Counter Based on MCNP Simulation
,”
Nucl. Electron. Detect. Technol.
,
30
(
12
), pp.
1626
–
1628
.https://link.oversea.cnki.net/doi/10.3969/j.issn.0258-0934.2010.12.018
5.
Ligao
,
C.
,
Xiaobo
,
L.
,
Jian
,
G.
,
Kan
,
W.
,
Xiaoqiang
,
F.
,
Yanpeng
,
Y.
, and
Chuanjiang
,
D.
,
2014
, “
Neutron Multiplicity Stochastic Simulation and Parameters Calculation Research on Big Cavity Detection System
,”
High Power Laser Part. Beams
,
26
(
1
), p.
014005
.10.3788/HPLPB20142601.14005
Google Scholar
Crossref
Search ADS
 
6.
Marin Ferrer
,
M.
,
Peerani
,
P.
,
Looman
,
M. R.
, and
Dechamp
,
L.
,
2007
, “
Design and Performances of the Scrap Neutron Multiplicity Counter
,”
Nucl. Instrum. Methods Phys. Res., Sect. A
,
574
(
2
), pp.
297
–
314
.10.1016/j.nima.2007.01.167
Google Scholar
Crossref
Search ADS
 
7.
Thornton
,
A. L.
,
2009
, “
Development of a Portable Neutron Coincidence Counter for Field Measurements of Nuclear Materials Using the Advanced Multiplicity Capabilities of MCNPX 2.5.F and the Neutron Coincidence Point Model
,” MS thesis,
Texas A&M University
, College Station, TX.
8.
Krick
,
M. S.
,
Ensslin
,
N.
,
Langner
,
D. G.
,
Miller
,
M. C.
,
Siebelist
,
R.
,
Stewart
,
J. E.
,
Ceo
,
R. N.
,
May
,
P. K.
, and
Collins
,
L. L.
,
1994
, “
Active Neutron Multiplicity Analysis and Monte Carlo Calculations
,” LANL, Los Alamos County, NM, Report No. LA-UR-94-2440.
9.
Eccleston
,
G. W.
,
Menlove
,
H. O.
,
Abhold
,
A. E.
,
Baker
,
M. C.
, and
Pecos
,
J. M.
,
1998
, “
The Underwater Coincidence Counter (UWCC) for Plutonium Measurements in Mixed Oxide Fuels
,” LANL, Los Alamos County, NM, Report No. LA-UR-98-3303.
10.
Wenming
,
Z.
,
Quanhu
,
Z.
,
Lin
,
Z.
,
Sufen
,
L.
,
Suxia
,
H.
, and
Liqun
,
Z.
,
2017
, “
Research on Detection Efficiency Spatial Distribution of Neutron Multiplicity Counting Detector
,”
Nucl. Electron. Detect. Technol.
,
37
(
12
), pp.
1223
–
1228
.https://link.oversea.cnki.net/doi/10.3969/j.issn.0258-0934.2017.12.013
11.
Yunfeng
,
L.
,
Quanhu
,
Z.
,
Qingxu
,
Y.
,
Yu
,
W.
, and
Wangtao
,
Y.
,
2023
, “
Simulation of Neutron Multiplicity Counter Quality Attribute Measurement Ability of Boron-Coated Straw Tube
,”
Nucl. Electron. Detect. Technol.
,
43
(
1
), pp.
94
–
100
.https://link.oversea.cnki.net/doi/10.3969/j.issn.0258-0934.2023.01.016
12.
Cailu
,
G.
,
Quanhu
,
Z.
,
Zhongjie
,
W.
, and
Jie
,
L.
,
2011
, “
Simulation on Function of Neutron Multiplicity Shift Register
,”
Nucl. Tech.
,
34
(
7
), pp.
553
–
555
.
13.
Weinmann-Smith
,
R.
,
Beddingfield
,
D. H.
,
Enqvist
,
A.
, and
Swinhoe
,
M. T.
,
2017
, “
Variations in AmLi Source Spectra and Their Estimation Utilizing the 5 Ring Multiplicity Counter
,”
Nucl. Instrum. Methods Phys. Res., Sect. A
,
856
, pp.
17
–
25
.10.1016/j.nima.2017.02.083
Google Scholar
Crossref
Search ADS
 
14.
Brown
,
D. A.
,
Chadwick
,
M. B.
,
Capote
,
R.
,
Kahler
,
A. C.
,
Trkov
,
A.
,
Herman
,
M. W.
,
Sonzogni
,
A. A.
, et al.,
2018
, “
ENDF/B-VIII.0: The 8 Th Major Release of the Nuclear Reaction Data Library With CIELO-Project Cross Sections, New Standards and Thermal Scattering Data
,”
Nucl. Data Sheets
,
148
, pp.
1
–
142
.10.1016/j.nds.2018.02.001
Google Scholar
Crossref
Search ADS
 
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