skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Boron-Coated Straw Collar for Uranium Neutron Coincidence Collar Replacement

Abstract

The objective of this project was to design and optimize, in simulation space, an active neutron coincidence counter (or collar) using boron-coated straws (BCSs) as a non- 3He replacement to the Uranium Neutron Coincidence Collar (UNCL). UNCL has been used by the International Atomic Energy Agency (IAEA) and European Atomic Energy Community (Euratom) since the 1980s to verify the 235U content in fresh light water reactor fuel assemblies for safeguards purposes. This report documents the design and optimization of the BCS collar.

Authors:
 [1];  [1];  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1339397
Report Number(s):
ORNL/TM-2016/696
DN4001030; MDGA517; TRN: US1701469
DOE Contract Number:
AC05-00OR22725
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION; URANIUM; BORON; WATER MODERATED REACTORS; URANIUM 235; NUCLEAR FUELS; STRAW; WATER COOLED REACTORS; DESIGN; FUEL ASSEMBLIES; OPTIMIZATION; SAFEGUARDS; SIMULATION; COINCIDENCE METHODS; FISSION NEUTRONS; ACTIVATION ANALYSIS

Citation Formats

Hu, Jianwei, Croft, Stephen, and McElroy, Robert Dennis. Boron-Coated Straw Collar for Uranium Neutron Coincidence Collar Replacement. United States: N. p., 2017. Web. doi:10.2172/1339397.
Hu, Jianwei, Croft, Stephen, & McElroy, Robert Dennis. Boron-Coated Straw Collar for Uranium Neutron Coincidence Collar Replacement. United States. doi:10.2172/1339397.
Hu, Jianwei, Croft, Stephen, and McElroy, Robert Dennis. Sun . "Boron-Coated Straw Collar for Uranium Neutron Coincidence Collar Replacement". United States. doi:10.2172/1339397. https://www.osti.gov/servlets/purl/1339397.
@article{osti_1339397,
title = {Boron-Coated Straw Collar for Uranium Neutron Coincidence Collar Replacement},
author = {Hu, Jianwei and Croft, Stephen and McElroy, Robert Dennis},
abstractNote = {The objective of this project was to design and optimize, in simulation space, an active neutron coincidence counter (or collar) using boron-coated straws (BCSs) as a non-3He replacement to the Uranium Neutron Coincidence Collar (UNCL). UNCL has been used by the International Atomic Energy Agency (IAEA) and European Atomic Energy Community (Euratom) since the 1980s to verify the 235U content in fresh light water reactor fuel assemblies for safeguards purposes. This report documents the design and optimization of the BCS collar.},
doi = {10.2172/1339397},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2017},
month = {Sun Jan 01 00:00:00 EST 2017}
}

Technical Report:

Save / Share:
  • The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report, providing results for model development of Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) designs, is a deliverable under Task 2 of the project.
  • The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube based alternative system in a configuration typically used for 3He-based coincidence counter applications. The specific application selected for boron-lined tube replacement in this project was one of the Uranium Neutron Coincidence Collar (UNCL) designs. This report, providing results for model development of a UNCL, is a deliverable under Task 2more » of the project. The current UNCL instruments utilize 3He tubes. As the first step in developing and optimizing a boron-lined proportional counter based version of the UNCL, models of eight different 3He-based UNCL detectors currently in use were developed and evaluated. A comparison was made between the simulated results and measured efficiencies for those systems with values reported in the literature. The reported experimental measurements for efficiencies and die-away times agree to within 10%.« less
  • He-3, a very rare isotope of natural helium gas, has ideal properties for the detection of thermal neutrons. As such it has become the standard material for neutron detectors and sees ubiquitous use within many radiometric applications that require neutron sensitivity. Until recently, there has been a fairly abundant supply of He-3. However, with the reduction in nuclear weapons, production of tritium ceased decades ago and the stockpile has largely decayed away, reducing the available He-3 supply to a small fraction of that needed for neutron detection. A suitable and rapidly-deployable replacement technology for neutron detectors must be found. Manymore » potential replacement technologies are under active investigation and development. One broad class of technologies utilizes B-10 as a neutron capture medium in coatings on the internal surfaces of proportional detectors. A particular implementation of this sort of technology is the boron-coated 'straw' (BCS) detectors under development by Proportional Technologies, Inc. (PTi). This technology employs a coating of B-10 enriched boron carbide (B{sub 4}C) on the inside of narrow tubes, roughly 4 mm in diameter. A neutron counter (e.g. a slab, a well counter, or a large assay counter designed to accommodate 200 liter drums) could be constructed by distributing these narrow tubes throughout the polyethylene body of the counter. One type of neutron counter that is of particular importance to safeguards applications is the Active Well Coincidence Counter (AWCC), which is a Los Alamos design that traditionally employs 42 He-3 detectors. This is a very flexible design which can accurately assay small samples of uranium- and plutonium-bearing materials. Utilizing the MCNPX code and benchmarking against measurements where possible, the standard AWCC has been redesigned to utilize the BCS technology. Particular aspects of the counter performance include the single-neutron ('singles') detection efficiency and the time constant for the decrease in neutron population in the counter following a fission event (a.k.a. the die-away time). Results of the modeling and optimization are presented. (authors)« less