Delayed neutron detection with an integrated differential die-away and delayed neutron instrument

Conference · Fri Jan 01 00:00:00 EST 2010

OSTI ID:1020958

Blanc, Pauline ^[1]; Tobin, Stephen J ^[1]; Lee, Taehoon ^[1]; Hu, Jianwei S ^[1]; Hendricks, John ^[1]; Croft, Stephen ^[1]

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1. Los Alamos National Laboratory

The Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy (DOE) has funded a multilab/university collaboration to quantify the plutonium (Pu) mass and detect the diversion of pins from spent nuclear fuel. The first two years of this NGSI effort was focused on quantifying the capability of a range of nondestructive assay (NDA) techniques with Monte Carlo (MCNPX) modeling and the second current phase involves measuring Spent Fuel. One of the techniques of interest in this paper involves measuring delayed neutrons. A delayed neutron instrument using 36 fission chambers and a 14 MeV neutron generator so called DT generator (Deuterium + Tritium) surrounding the fuel was previously studied as part of the NGSI effort. This paper will quantify the capability of a standalone delayed neutron instrument using 4 {sup 3}He gas filled tubes and a DT generator with significant spectrum tailoring, located far from the fuel. So that future research can assess how well a delayed neutron instrument will function as part of an integrated NDA system. A new design is going to be used to respond to the need of the techniques. This design has been modeled for a water media and is currently being optimized for borated water and air media as part of ongoing research. This new design was selected in order to minimize the fission of {sup 238}U, to use a more realistic neutron generator design in the model, to reduce cost and facilitate the integration of a delayed neutron (DN) with a differential die-away (DDA) instrument. Since this paper will focus on delayed neutron detection, the goal is to quantify the signal from {sup 235}U, {sup 239}Pu and {sup 241}Pu, which are the isotopes present in Spent Fuel that respond significantly to a neutron interrogation. This report will quantify the capability of this new delayed neutron design to measure the combined mass of {sup 235}U, {sup 239}Pu and {sup 241}Pu for 16 of the 64 assemblies of the NGSI Spent Fuel library in one of the three media, water.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1020958
• Report Number(s): LA-UR-10-04125; LA-UR-10-4125; TRN: US201116%%636
• Resource Relation: Conference: 51st INMM Conference ; July 11, 2010 ; Baltimore, MD
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
DELAYED NEUTRONS
DESIGN
DETECTION
DEUTERIUM
FISSION
FISSION CHAMBERS
FUELS
HELIUM 3
ISOTOPES
MEASURING INSTRUMENTS
MEETINGS
NEUTRON GENERATORS
NEUTRONS
NONDESTRUCTIVE ANALYSIS
NUCLEAR FUELS
PLUTONIUM
PLUTONIUM 239
PLUTONIUM 241
SAFEGUARDS
SIMULATION
SPENT FUELS
TRITIUM
URANIUM 235
URANIUM 238