Affordable Cleanup? Opportunities for Cost Reduction in the Decontamination and Decommissioning of the Nation's Uranium Enrichment Facilities (1996) / Chapter Skim
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H: PREVIOUS DECONTAMINATION AND DECOMMISSIONING EFFORTS
H: PREVIOUS DECONTAMINATION AND DECOMMISSIONING EFFORTS
Pages 244-255
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From page 244... ...
Timely decisions on key issues are essential to execute the work efficiently within budget and schedule. CAPENHURST GASEOUS DIFFUSION PLANT Description of Capenhurst Facility The Capenhurst GDP enrichment cascade consisted of 4,808 stages in series, each containing a converter housing the diffusion barrier material that separates uranium-235 (235U)
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From page 245... ...
This removal allowed a part of the process building housing the cascade to be demolished and the land returned to greenfield status. Other parts of the process building were reused to house equipment for size reduction of components, chemical decontamination, and melting of metal components and pieces that were difficult to decontaminate.
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From page 246... ...
, to volatile fluoride compounds; plant characterization to identify and quantify residual deposits of radioactive materials; removal of nonradioactive hazardous materials such as asbestos and polychlorinated biphenyls (PCBs) ; removal and interim storage of plant equipment and removal of cell structures; size reduction of components; aqueous chemical decontamination; melting difficult-to-decontaminate metal parts; removal of process and ancillary building structures; and disposal of radioactive and hazardous waste.
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From page 247... ...
The diffusion plant cascade equipment removed was stored outdoors for up to 9 years until the new decontamination facility was available. Approximately 6,000 metric tons of contaminated components were stored, including 700 large stages weighing up to 7 metric tons each.
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From page 248... ...
Following extensive laboratory and pilot plant investigation, a full-scale decontamination plant was built in 1989. The flowsheet was based on achieving plant discharges having a negligible impact on the environment, and on satisfying the United Kingdom statutory regulations for recycling scrap metals to the open market.
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From page 249... ...
Personnel Protection During Decommissioning Personnel protection was achieved through multiple methods: Criticality Control strict criticality control with criticality detectors on selected operations; extensive alpha-in-air monitoring; and special HVAC systems with high-efficiency particulate air filters. Criticality control was achieved by a number of actions: · removing as much uranic contamination as possible during the size reduction, decontamination, and preparation stages; designing the plant to minimize the likelihood of criticality incidents; and
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From page 250... ...
The mean total dose for 1993 was 0.03 mSv. These low levels were achieved by sound engineering design, safe operational practices, and a methodical approach to safety.
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From page 251... ...
Table H-3 presents the ratio of Oak Ridge to Capenhurst GDP for total metals contained in the cascade, building footprint, total area under roof, weight of largest converter, and peak electric power. A direct comparison of plant separative work capacities was not possible because the Capenhurst capacity is considered to be proprietary information.
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From page 252... ...
~ . a Because the largest Capenhurst converter had an integral compressor, the weight of the converter shown for the Oak Ridge GDP includes the converter and the compressor as well.
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From page 253... ...
b Because the largest Capenhurst converter had an integral compressor, the weight of the converter shown for the Oak Ridge GDP includes the converter and the compressor as well. SOURCE: Clements (1993; 1994a,b)
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From page 254... ...
1989. British Nuclear Fuels pie Process for Decontamination and Decommissioning of Capenhurst Gaseous Diffusion Plant and Information from the International Conference on Decommissioning of Major Radioactive Facilities.
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From page 255... ...
Presented at the 15th Annual Meeting of the World Nuclear Fuel Market, held in Seville, Spain, October 16-19, 1988.
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