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Title: High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys

Abstract

The Y-12 National Security Complex is playing a role in the U.S. High Performance Research Reactor (USHPRR) Conversion program sponsored by the U.S. National Nuclear Security Administration's Office of Global Threat Reduction. The USHPRR program has a goal of converting remaining U.S. reactors that continue to use highly enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. The USHPRR program is currently developing a LEU Uranium-Molybdenum (U-Mo) monolithic fuel for use in the U.S. high performance research reactors.Y-12 is supporting both the fuel development and fuel fabrication efforts by fabricating low enriched U-Mo foils from its own source material for irradiation experiments and for optimizing the fabrication process in support of scaling up the process to a commercial production scale. Once the new fuel is qualified, Y-12 will produce and ship U-Mo coupons with verified 19.75% +0.2% - 0.3% U-235 enrichment to be fabricated into fuel elements for the USHPRRs. Considering this small enrichment tolerance and the transition into HEU being set strictly at 20% U-235, a characterization system with a measurement uncertainty of less than or equal to 0.1% in enrichment is desired to support customer requirements and minimize production costs. Typical uncertainty for most available characterization systemsmore » today is approximately 1-5%; therefore, a specialized system must be developed which results in a reduced measurement uncertainty. A potential system using a High-Purity Germanium (HPGe) detector has been procured, and tests have been conducted to verify its capabilities with regards to the requirements. Using four U-Mo enrichment standards fabricated with complete isotopic and chemical characterization, infinite thickness and peak-ratio enrichment measurement methods have been considered for use. As a result of inhomogeneity within the U-Mo samples, FRAM, an isotopic analysis software, has been selected for initial testing. A systematic approach towards observing effects on FRAM's enrichment analysis has been conducted with regards to count and dead time.« less

Authors:
; ;
Publication Date:
Research Org.:
Oak Ridge Y-12 Plant (Y-12), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Defense Programs (DP)
OSTI Identifier:
1043888
Report Number(s):
Y/DW-2272
TRN: US1203230
DOE Contract Number:  
DE-AC05-00OR22800
Resource Type:
Conference
Resource Relation:
Conference: INMM 53rd Annual Meeting, Orlando, FL, July 15-19, 2012
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; ACCURACY; ALLOYS; DEAD TIME; ENRICHED URANIUM; FABRICATION; FUEL ELEMENTS; GERMANIUM; HIGHLY ENRICHED URANIUM; IRRADIATION; MOLYBDENUM; PERFORMANCE; PRODUCTION; RESEARCH REACTORS; SECURITY; TESTING; THICKNESS; TOLERANCE; URANIUM; VERIFICATION

Citation Formats

Lillard, C. R., Hayward, J. P., and Williamson, M. R. High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys. United States: N. p., 2012. Web.
Lillard, C. R., Hayward, J. P., & Williamson, M. R. High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys. United States.
Lillard, C. R., Hayward, J. P., and Williamson, M. R. Thu . "High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys". United States. https://www.osti.gov/servlets/purl/1043888.
@article{osti_1043888,
title = {High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys},
author = {Lillard, C. R. and Hayward, J. P. and Williamson, M. R.},
abstractNote = {The Y-12 National Security Complex is playing a role in the U.S. High Performance Research Reactor (USHPRR) Conversion program sponsored by the U.S. National Nuclear Security Administration's Office of Global Threat Reduction. The USHPRR program has a goal of converting remaining U.S. reactors that continue to use highly enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. The USHPRR program is currently developing a LEU Uranium-Molybdenum (U-Mo) monolithic fuel for use in the U.S. high performance research reactors.Y-12 is supporting both the fuel development and fuel fabrication efforts by fabricating low enriched U-Mo foils from its own source material for irradiation experiments and for optimizing the fabrication process in support of scaling up the process to a commercial production scale. Once the new fuel is qualified, Y-12 will produce and ship U-Mo coupons with verified 19.75% +0.2% - 0.3% U-235 enrichment to be fabricated into fuel elements for the USHPRRs. Considering this small enrichment tolerance and the transition into HEU being set strictly at 20% U-235, a characterization system with a measurement uncertainty of less than or equal to 0.1% in enrichment is desired to support customer requirements and minimize production costs. Typical uncertainty for most available characterization systems today is approximately 1-5%; therefore, a specialized system must be developed which results in a reduced measurement uncertainty. A potential system using a High-Purity Germanium (HPGe) detector has been procured, and tests have been conducted to verify its capabilities with regards to the requirements. Using four U-Mo enrichment standards fabricated with complete isotopic and chemical characterization, infinite thickness and peak-ratio enrichment measurement methods have been considered for use. As a result of inhomogeneity within the U-Mo samples, FRAM, an isotopic analysis software, has been selected for initial testing. A systematic approach towards observing effects on FRAM's enrichment analysis has been conducted with regards to count and dead time.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {6}
}

Conference:
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