Repository Criticality Control with Depleted-Uranium-Dioxide Cermet Waste Packages

Conference · Wed Nov 14 04:00:00 EST 2001

OSTI ID:788682

Forsberg, Charles W. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); ORNL

It is proposed that the structural components and internal basket structures of waste packages (WPs) be constructed of depleted uranium dioxide (DUO₂)-steel cermets. The cermet contains DUO₂ imbedded in a steel matrix. The WPs are filled with spent nuclear fuel (SNF) and placed 2 in a geological repository. The WP provides a handling container for placement of SNF in the repository and is an engineered barrier to delay SNF degradation and subsequent release of radionuclides. SNF and other fissile wastes contain enriched uranium and transuranic fissile isotopes; thus, the potential for nuclear criticality exists. Most of the transuranic fissile isotopes, such as ²³⁹Pu, will have decayed to ²³³U or ²³⁵U before significant fissile-isotope migration from the degraded SNF or other fissile waste forms has occurred. Consequently, post-closure repository criticality issues are primarily from the fissile isotopes of uranium. As the WP degrades, the ²³⁸U in the DUO₂-steel cermet would mix with the degrading SNF and isotopically dilute ²³³U and ²³⁵U to levels that would ensure that post-closure criticality would not occur.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 788682
• Report Number(s): P01-111254
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
CERMETS
CRITICALITY
Cermet
DEPLETED URANIUM
ENRICHED URANIUM
Isotopic Dilution
Light-Water Reactor (LWR)
Nuclear Criticality Safety Program (NCSP)
Pressurized-Water Reactor (PWR)
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE FACILITIES
RADIOISOTOPES
SAFETY ANALYSIS
SPENT FUELS
Spent Nuclear Fuel (SNF)
U.S. Nuclear Regulatory Commission (NRC)
URANIUM DIOXIDE
WASTE FORMS
Waste Packages (WPs)