Decommissioning the Fuel Process Building, a Shift in Paradigm for Terminating Safeguards on Process Holdup
INMM Abstract 51st Annual Meeting Decommissioning the Fuel Process Building, a Shift in Paradigm for Terminating Safeguards on Process Holdup The Fuel Process Building at the Idaho Nuclear Technology and Engineering Center (INTEC) is being decommissioned after nearly four decades of recovering high enriched uranium from various government owned spent nuclear fuels. The separations process began with fuel dissolution in one of multiple head-ends, followed by three cycles of uranium solvent extraction, and ending with denitration of uranyl nitrate product. The entire process was very complex, and the associated equipment formed an extensive maze of vessels, pumps, piping, and instrumentation within several layers of operating corridors and process cells. Despite formal flushing and cleanout procedures, an accurate accounting for the residual uranium held up in process equipment over extended years of operation, presented a daunting safeguards challenge. Upon cessation of domestic reprocessing, the holdup remained inaccessible and was exempt from measurement during ensuing physical inventories. In decommissioning the Fuel Process Building, the Idaho Cleanup Project, which operates the INTEC, deviated from the established requirements that all nuclear material holdup be measured and credited to the accountability books and that all nuclear materials, except attractiveness level E residual holdup, be transferred to another facility. Instead, the decommissioning involved grouting the process equipment in place, rather than measuring and removing the contained holdup for subsequent transfer. The grouting made the potentially attractiveness level C and D holdup even more inaccessible, thereby effectually converting the holdup to attractiveness level E and allowing for termination of safeguards controls. Prior to grouting the facility, the residual holdup was estimated by limited sampling and destructive analysis of solutions in process lines and by acceptable knowledge based upon the separations process, plant layout, and operating history. The use of engineering estimates, in lieu of approved measurement methods, was justified by the estimated small quantity of holdup remaining, the infeasibility of measuring the holdup in a highly radioactive background, and the perceived hazards to personnel. The alternate approach to quantifying and terminating safeguards on process holdup was approved by deviation.
- Research Organization:
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
- Sponsoring Organization:
- OTHER
- DOE Contract Number:
- DE-AC07-05ID14517
- OSTI ID:
- 993543
- Report Number(s):
- INL/CON-10-17864; TRN: US1008094
- Resource Relation:
- Conference: Institute of Nuclear Materials Management - 51st Annual Meeting,Baltimore, Maryland,07/11/2010,07/15/2010
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DECOMMISSIONING
DENITRATION
DISSOLUTION
ENRICHED URANIUM
GROUTING
INVENTORIES
NUCLEAR FUELS
NUCLEAR MATERIALS MANAGEMENT
PERSONNEL
REPROCESSING
SAFEGUARDS
SAMPLING
SOLVENT EXTRACTION
URANIUM
URANYL NITRATES
Decommissioning
INMM
Paradigm
Terminating