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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2 THE GDP SITES: PROCESS, FACILITIES, INVENTORIES, AND RISKS
2 THE GDP SITES: PROCESS, FACILITIES, INVENTORIES, AND RISKS
Pages 27-48
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From page 27... ...
The only method currently in commercial use in the United States is the gaseous diffusion process, which is based on the slight difference in mass between the 23sU and 238U (uranium-235 and uranium-23 S respectively)
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From page 28... ...
COMPRESSOR CONTROL VALVE LOW ~ . 1 FROM_ l PREVIOUS ~ _ :0 STAGE~ 1 r FIGURE 2-2 Gaseous diffusion stage schematic.
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From page 29... ...
The process buildings contain thousands of enrichment stages with connecting piping, valving, and compressors, and there are additional connections between the process buildings. Both axial flow and centrifugal compressors are used to compress the UFO gas to the pressures needed for it to flow through the barrier tubes and from one stage to another.
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From page 30... ...
of the main cascade and stored in 10- to 14-ton cylinders on site in a solid form. Light gases, which are readily separable from the heavier UFO, are removed in a special "purge cascade." In addition to the process stage equipment, the GDPs require auxiliary systems, such as UFO feed and withdrawal, electrical power distribution, and cooling towers to dissipate the waste process heat.
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From page 31... ...
The operating plants at Paducah and Portsmouth are significant employers in their localities. All three plants are located near water bodies: Poplar Creek runs through the Oak Ridge GDP site and the Clinch River and Watts Bar Lake bound the site; at Portsmouth, the Scioto River, which flows into the Ohio River, is 3 miles to the west; and at the Paducah GDP, the Big and Little Bayou Creeks bound the site and flow into the Ohio River, approximately 3 miles to the north.
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From page 32... ...
32 Cal ._ 4 ._ ._ V Ct V ._ ·s Ct o U
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From page 33... ...
However, the process buildings account for most of the estimated D&D cost for the GDPs (see Chapter 41. For the Oak Ridge site, the Ebasco cost estimate indicates that the five process buildings account for 92.6 percent of the D&D cost.
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From page 34... ...
Aluminum/copper8.5 6.1 7.6 22.2 Copper wire tubing/valves17.6 11.7 15.0 44.3 Monet pipe/valvesa1.7 1.2 1.5 4.4 Nickel22.1 15.9 19.8 57.8 Miscellaneous123.2 81.9 105.0 310.1 NOTE: Ferrous metals and steel excludes some structural steel left in place in decontaminated building structures. Miscellaneous includes electrical instrumentation equipment and housings.
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From page 35... ...
Thirteen buildings at the Oak Ridge site and six buildings at Portsmouth house gas centrifuge enrichment facilities that are covered by the D&D program. These facilities are contaminated and contain classified equipment and materials.
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From page 36... ...
More uranium compounds will undoubtedly be spread by dismantling activities, although great care will be taken to avoid the spread of radioactive or hazardous materials in amounts above that permitted by DOE Orders or federal and state statutes. The extent of contamination on external surfaces in the facilities, such as floors, walls, structural steel, and exterior surfaces of process equipment and instrumentation, is not well known.
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From page 38... ...
Of the several tons of uranium deposits, much of it is enriched and could present a criticality hazard in the presence of water.7 A number of the stages at the Oak Ridge and Portsmouth GDPs will contain highly enriched uranium as well as moderately enriched uranium having enrichment levels between 5 and 20 percent (Murray, 19941. Most of the radioactive contamination, both within the process equipment and on exposed areas in the plants, occurs on the surface of materials and should be easily removable.
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From page 39... ...
39 cd Em GO o A cd o At At · c~ o ct 5 Ct ·E 4 U: 1 CO o Cal Cal ·~ ~ U
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From page 40... ...
40 at · · · v ct 4 v · at · ~ cd A, c · ct o v cn o 'e ct o at ~ cd ·S at At a: 1 so o ~ - ~ at · - ^ o ~,4 o ~ ~ :, 3~ Cal V Cal o Cal an ct =4 .
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From page 41... ...
Cleanup of these materials does not represent a large component of the D&D cost estimates. STORAGE OF DUF6 DOE has responsibility for the 52S,000 metric tons of DUF6 that are stored in approximately 46,000 steel cylinders at the 3 sites.
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From page 42... ...
For this reason, as well as for control of special nuclear materials, the DOE has initiated a deposit removal program to remove, either mechanically or with low temperature gaseous treatment, highly enriched uranium deposits. The goal of phase ~ of this program is to remove deposits of more than 500 g in an unfavorable geometry from about 60 components in the Oak Ridge process equipment.
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From page 43... ...
As the facilities age, and the containment integrity of the process equipment and buildings begins to fail, the risk of exposure of the public to Me contaminants will tend to slowly increase.
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From page 44... ...
.. Rainwater, particularly after significant roof and process equipment decay, can transport contaminants into groundwater and surface water supplies.
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From page 45... ...
. Sufficient masses of enriched uranium to create a criticality risk may be present in deposits internal to process equipment, or may accrue from waterborne transport of soluble uranium (either in the process equipment or during Improper aqueous decontamination operations)
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From page 46... ...
However, active management and maintenance will be required until the enriched uranium deposits are removed from the process equipment. CONCLUSIONS In summary, the GDP sites are large facilities with substantial quantities of contaminants.
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From page 47... ...
Presented to the Committee on Decontamination and Decommissioning of Uranium Enrichment Facilities, Oak Ridge Uranium Enrichment Facility, Oak Ridge, Tennessee, February 3, 1994. EPA (Environmental Protection Agency)
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From page 48... ...
from Gary Person, Oak Ridge GDP site, to George Gans, Booz Allen, February 4, 1995, forwarded to the Committee on Decontamination and Decommissioning of Uranium Enrichment Facilities. Person, G
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