High-Energy Delayed Gamma Spectroscopy for Spent Nuclear Fuel Assay

Journal Article · Tue Feb 01 04:00:00 EST 2011 · IEEE Transactions on Nuclear Science, 58(1):231-240

DOI:https://doi.org/10.1109/TNS.2010.2095039· OSTI ID:1009707

Campbell, Luke W; Smith, Leon E; Misner, Alex C

High-accuracy, direct, nondestructive measurement of fissile and fissionable isotopes in spent fuel, particularly the Pu isotopes, is a well-documented, but still unmet challenge in international safeguards. As nuclear fuel cycles propagate around the globe, the need for improved materials accountancy techniques for irradiated light-water reactor fuel will increase. This modeling study investigates the use of delayed gamma rays from fission-product nuclei to directly measure the relative concentrations of U-235, Pu-239, and Pu-241 in spent fuel assemblies. The method is based on the unique distribution of fission-product nuclei produced from fission in each of these fissile isotopes. Fission is stimulated in the assembly with a pulse-capable source of interrogating neutrons. The measured distributions of the short-lived fission products from the unknown sample are then fit with a linear combination of the known fission-product yield curves from pure U-235, Pu-239, and Pu-241 to determine the original proportions of these fissile isotopes. Modeling approaches for the intense gamma-ray background promulgated by the long-lived fission-product inventory and for the high-energy gamma-ray signatures emitted by short-lived fission products from induced fission are described. Benchmarking measurements are presented and compare favorably with the results of these models. Results for the simulated assay of simplified individual fuel elements ranging from fresh to 60 GWd/MTU burnup demonstrate the utility of the modeling methods for viability studies, although additional work is needed to more realistically assess the potential of High-Energy Delayed Gamma Spectroscopy (HEDGS).

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1009707
• Report Number(s): PNNL-SA-69743; NN4003070
• Journal Information: IEEE Transactions on Nuclear Science, 58(1):231-240, Journal Name: IEEE Transactions on Nuclear Science, 58(1):231-240 Journal Issue: 1 Vol. 58; ISSN 0018-9499; ISSN IETNAE
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
BURNUP
DISTRIBUTION
FISSION
FISSION PRODUCTS
FUEL ELEMENTS
GAMMA SPECTROSCOPY
NEUTRONS
NUCLEAR FUELS
NUCLEI
SAFEGUARDS
SIMULATION
SPENT FUELS
VIABILITY