Safe Dissolution of High Flux Isotope Reactor Cores

Conference · Sun Sep 13 04:00:00 EDT 2015

OSTI ID:1222739

Williamson, Brittany ^[1]; Lint, John ^[1]; Clifton, Bill ^[1]

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1. Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States)

The H-Canyon facility at the Savannah River Site is the U.S.A.’s only remaining full- scale chemical separations plant. H-Canyon maintains the capacity to safely and efficiently disposition a large inventory of excess nuclear material from across the Department of Energy (DOE) complex and used nuclear fuel from foreign and domestic research reactors. One such fuel that H-Canyon may dissolve is cores from the High Flux Isotope Reactor (HFIR). By employing realistic analysis, the need for administrative controls was eliminated. A new criticality modeling approach has eliminated the need for administrative controls for HFIR dissolution operations in H-Canyon. The primary upsets of concern are an over-mass event and an overconcentration event. Several initiating events were considered for each type of upset. Over-concentration events were deemed to be not credible by taking credit for the chemistry of acid consumption, i.e. there are not enough moles of acid to dissolve enough moles of uranium in order to reach a critical configuration. Over-mass events were deemed to be not credible by taking credit for the annular design of the fuel elements. By using realistic analysis, both types of upsets have been shown to be subcritical, and therefore administrative controls are not needed to prevent an inadvertent criticality. In this paper, the new methodology for performing criticality analyses for dissolving HFIR fuel elements will be presented, and the elimination of administrative controls will be discussed.

• Research Organization: Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); USDOE Office of Environmental Management (EM)
• DOE Contract Number: AC09-08SR22470
• OSTI ID: 1222739
• Report Number(s): SRNS-STI-2015-00365
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
HFIR
Nuclear Criticality Safety Program (NCSP)
chemistry
dissolving
realism
reprocessing