The use of passive, secure cells for processing of highly active nuclear wastes
- EnergySolutions, Richland, WA (United States)
Passive, secure cells (PSCs) have been used for over 50 years at the Sellafield nuclear site in the UK for radioactive processing plants. PSCs are designed and constructed with the expectation that there will be no need to enter them throughout the life of the plant. EnergySolutions has full and exclusive rights in North America to use the intellectual property and know-how generated at the Sellafield site and this includes all the design and operational data for PSCs. These data are thus available for use in the new build of nuclear plant currently being envisaged under the GNEP initiative. There are three types of PSC. Type 1 PSCs contain plant items with no maintainable moving parts, and pipework is all welded and radiographed to nuclear standards. Type 2 PSCs contain plant items with slowly rotating or intermittently moveable parts, but all maintainable items such as motors and gearboxes are located outside the cell, with sealed through-cell-wall drives. Type 3 PSCs are a newer design, dating from the 1980's, in which all maintainable in-cell items are designed as removable modules. The housings for the equipment are permanently welded into the in-cell pipework, and the modules can be withdrawn from these housings, through removable hatches in the PSC roof, into shielded steel 'flasks'. The flasks are moved to a maintenance cell where the modules are repaired or prepared for disposal. The process is reversed to re-install the modules back into service in the PSC. All three types of PSC have been shown to have operability, maintainability, reliability, space utilization, contamination control and worker radiation dose uptake advantages over canyon-based plants. The increased capital cost of PSCs over canyons is offset by decreased operating costs. Although PSCs have lower flexibility for process change than do canyons, this can be mitigated by the provision of spare cells and pipework at the design stage. Entry to PSCs is possible but has been required only rarely at Sellafield. Design features of PSCs minimize the potential for internal contamination and therefore such entries are actually easier and subject workers to a lower dose-uptake than canyon entries. (authors)
- Research Organization:
- WM Symposia, 1628 E. Southern Avenue, Suite 9 - 332, Tempe, AZ 85282 (United States)
- OSTI ID:
- 21294755
- Report Number(s):
- INIS-US-09-WM-07426; TRN: US10V0288040945
- Resource Relation:
- Conference: WM'07: 2007 Waste Management Symposium - Global Accomplishments in Environmental and Radioactive Waste Management: Education and Opportunity for the Next Generation of Waste Management Professionals, Tucson, AZ (United States), 25 Feb - 1 Mar 2007; Other Information: Country of input: France; 4 refs
- Country of Publication:
- United States
- Language:
- English
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