Piping Design Turnover Program
I. PURPOSE AND SCOPE
Some design drawings and calculations have been found to differ from the as-built condition of piping and related equipment in the plant. One of the primary causes of this problem is incomplete turnover of detailed design information from the architect/engineer. The Piping Design Turnover Program is locating, packaging, and turning over to CP&L the UE&C pipe stress and pipe support calculations for Brunswick. CP&L is reviewing the calculations that are safety related and, where needed, upgrading them. Where safety related design calculations are missing, they are being recreated. Also, some plant walk-downs are being conducted where needed to verify drawing information.
The Piping Design Turnover Program will result in over 5000 revised piping-support drawings. In addition, over 400 piping isometric drawings and supporting calculation packages will be provided. The turnover and validation for large-bore piping systems is approximately 85% complete; for small-bore systems it is about 45% complete. The BNP Piping Design Control organization will integrate data into existing plant information systems (NRCS and EDBS) and will establish procedures to assure continued integrity of design information.
Following project completion, an audit will be conducted to verify the consistency among related drawings, calculations, and the as-built plant configuration. Also, the administrative procedures for plant modifications will be updated to ensure continued maintenance of design basis documents.
II. EVALUATION
Schedule Index: 11 - This project has resulted in the changeout or modification of over 400 piping supports for safety systems. Of the 400 piping supports affected, about 200 involve the RHR system, including RHR service water. In most cases, these piping supports were adequate for their basic function, but they were not fully qualified. Thus, the actual impact of this project on RHR and service water system performance is considered to be low. However, because the RHR and service water system are high contributors to theoretical core melt frequency, a nuclear safety scaling factor of 0.2 is assigned (0.2 x 32). If design basis issues are not resolved, unit availability concerns could arise (0.2 x 12). Some personnel radiation exposure is incurred during walkdowns (-0.2 x 9). The potential for increased efficiency in future design activities results in a significant plant enhancement (0.5 x 8).
Economic Aspects: The compiled design documents will improve efficiency in developing future modifications and in conducting operability evaluations. Long term maintenance of the affected piping design bases will be incorporated as a routine part of plant work that is already funded and staffed. The related data base management and design control activities are also already part of the routine plant work and staffing and are adequate to support long term requirements. Therefore, the net long term impact of this project is a reduction in BNP costs.
Related Standards: The applicable Work Management Policy for this project concerns design documentation.
Other Considerations: This type of documentation problem resulted in NRC IEB 79-14. Final closeout of IEB 79-14 issues and resolution of NCR S-86-021 are dependent on this project. CP&L plans to complete this project by the end of outages B109R1 (Unit 1) and B211R1 (Unit 2). The service water lubricating water and service water diesel generator supply and return systems are not within the scope of the NRC commitment. These systems are currently being modified and/or replaced; consequently, the associated design packages, prepared by CP&L, contain current design documentation.
III. CONCLUSION
This project will proceed as scheduled due to the importance of having accurate design basis documentation readily available.
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