Lessons Learned from Most Recent Chemical Decontamination for Decommissioning Projects - 19280
- Westinghouse Electric Company (United States)
In 2017, Westinghouse performed a full system chemical decontamination of Units 1 and 2 of the Bohunice V1 Nuclear Power Plant. Bohunice V1 is a VVER 440 design with six loops. The application was performed two loops at a time, with the reactor core bypassed. The Pressurizer and Pressurizer Relief Tank (Bubble Tank) were decontaminated as well, in a separate application. This was a recovery decontamination that had been attempted by another company prior to Westinghouse. Several modifications to equipment and design of process were required to make the decontamination successful. The project was initiated to perform pre-dismantling chemical decontamination of primary circuits of both V1 units using Decontamination for Decommissioning (DfD) to meet the following objectives (see References 1 and 2 for process descriptions of DfD): - Remove activity from the primary circuit components; - Reduce dose rates around piping and components; - Simplify access to the installations, making it possible to use hands-on techniques for dismantling, rather than the more expensive use of robotics or manipulators; - Minimize the potential for spreading contamination during decommissioning activities - Reduce the activity of components that they may be disposed of at a lower classification, therefore more economical, waste disposal category. Several techniques were employed that were unique, or first of a kind, to aid in the decontamination, including resin regeneration and bypass of the reactor core, while still providing enough flow to to allow sufficient dispersal through all the steam generator tubes. Equipment that was already available on site was evaluated and, when possible, combined with Westinghouse equipment to minimize application cost and schedule. The lessons learned from the first unit (Unit 2) were applied to the second unit (Unit 1) application. The partial relocation of equipment allowed for the most efficient schedule to complete the second decontamination. The paper will describe in more detail the results and lessons learned from the full system chemical decontaminations performed, as well as updates on another recent decontamination project. (authors)
- Research Organization:
- WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
- OSTI ID:
- 23003037
- Report Number(s):
- INIS-US-21-WM-19280; TRN: US21V1153043370
- Resource Relation:
- Conference: WM2019: 45. Annual Waste Management Conference, Phoenix, AZ (United States), 3-7 Mar 2019; Other Information: Country of input: France; 2 refs.; available online at: https://www.xcdsystem.com/wmsym/2019/index.html
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BOHUNICE V-1 REACTOR
DECONTAMINATION
DOSE RATES
MANIPULATORS
MODIFICATIONS
NUCLEAR INDUSTRY
PRESSURIZERS
REACTOR CORES
REACTOR DECOMMISSIONING
REMEDIAL ACTION
RESINS
STEAM GENERATORS
SURFACE CONTAMINATION
TANKS
WASTE DISPOSAL