A system for the measurement of delayed neutrons and gammas from special nuclear materials
The delayed neutron counting system at the Royal Military College of Canada has been upgraded to accommodate concurrent delayed neutron and gamma measurements. This delayed neutron and gamma counting system uses a SLOWPOKE-2 reactor to irradiate fissile materials before their transfer to a counting arrangement consisting of six 3He and one HPGe detector. The application of this system is demonstrated in an example where delayed neutron and gamma emissions are used in complement to examine 233U content and determine fissile mass with an average relative error and accuracy of −2.2 and 1.5 %, respectively.
KeywordsDelayed neutron counting Delayed gamma Nuclear forensics MCNP
Project funding has been provided by a Canadian Nuclear Safety Commission Doctoral Award, and Natural Sciences and Engineering Research Council of Canada. The technical work and assistance of J. Shaw, C. McEwen, K. Nielsen, K. Mattson, and D. Ferguson is much appreciated.
- 4.The Hague Nuclear Security Summit Communiqué, Nuclear Security Summit 2014. https://www.nss2014.com/sites/default/files/documents/the_hague_nuclear_security_summit_communique_final.pdf Accessed 28 Oct 2014
- 5.Canada’s National Statement–Nuclear Security Summit, Nuclear Security Summit 2014. https://www.nss2014.com/sites/default/files/documents/canada_-_nss_2014_-_national_statement_-_en_3.pdf Accessed 28 Oct 2014
- 6.Consolidated Canadian results to the HEU round robin exercise, Defence Research and Development Canada. http://cradpdf.drdc-rddc.gc.ca/PDFS/unc62/p522801.pdf Accessed 28 Oct 2014
- 7.Round robin 3 exercise after action and lessons learned report, International Technical Working Group. http://www.nf-itwg.org/sites/default/files/pdfs/Round_Robin_3_Final_Report.pdf Accessed 28 Oct 2014
- 11.Keepin GR, Wimett TF, Zeigler RK (1957) Delayed neutrons from fissionable isotopes of uranium, plutonium and thorium. J Nucl Energy 6:IN2–21Google Scholar
- 12.Myers WL, Goulding CA, Hollas CL (2006) Determination of the 235U enrichment of bulk uranium samples using delayed neutrons. In PHYSOR-2006: Vancouver, Sept 10–14 2006 (CD ROM)Google Scholar
- 14.Sellers MT, Corcoran EC, Kelly DG (2012) Simultaneous 233U and 235U characterization through the assay of delayed neutron temporal behaviour. In PHYSOR 2012: Knoxville, Tennessee, April 15-20, 2012Google Scholar
- 16.Goorley T, James M, Booth T, Brown F, Bull J, Cox LJ, Durkee J, Elson J, Fensin M, Forster RA, Hendricks J, Hughes HG, Johns R, Kiedrowski B, Martz R, Mashnik S, McKinney G, Pelowitz D, Prael R, Sweezy J, Waters L, Wilcox T, Zukaitis T (2012) Initial MCNP6 release overview. J Nucl Tech 180:298–315CrossRefGoogle Scholar
- 17.Andrews MT, Goorley JT, Corcoran EC, Kelly DG (2014) Modeling the detection of delayed neutron signatures in MCNP6 and comparisons with experimental 233U, 235U, and 239Pu measurements. J Nucl Tech 187:235–243Google Scholar
- 18.MCNP6.1.1–Beta release notes, Goorley T. https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/la-ur-14-24680.pdf Accessed Oct 28 2014
- 26.Andrews MT, Goorley JT, Corcoran EC, Kelly DG (2014) Uranium and Plutonium Fission Product Gamma Intensity Measurements and MCNP6 Simulations. Trans Am Nucl Soc 110:490–493Google Scholar
- 28.Knoll GF (2010) Radiation detection and measurement. Wiley, HobokenGoogle Scholar