05000498/FIN-2010003-03
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Inadequate Design Change Review of AMSAC |
| Description | The inspectors identified a Green finding for the failure to identify specific design parameters and the impact of changes on the anticipated transient without scram mitigation system actuation circuitry (AMSAC) in accordance with station Procedure 0PGP04-ZE-0309, Design Change Package, Revision 6. In 1999, the licensee performed a design change review to replace steam generators in Unit 1 and 2. In conjunction with steam generator replacement, the licensee switched from using Logic 2 (low main feedwater flow) of the generic AMSAC design to Logic 1 (low steam generator water level) of the generic AMSAC design. However, the licensee failed to identify and evaluate the impacts to the C-20 permissive disarming time delay setting, which was required to be changed from 260 seconds to 360 seconds for Logic 1 (low steam generator water level). The licensees corrective action plan is to update the C- 20 permissive disarming time delay setting with a site specific value. This issue was entered into the licensees corrective action program as Condition Report 10-3630. The finding is more than minor because the reduced time delay may have affected the availability of AMSAC to perform its function to initiate auxiliary feedwater when necessary and therefore affected the Mitigating Systems Cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Using Phase 1 of the Significance Determination Process as described in Inspection Manual Chapter 0609, Attachment 4, dated January 10, 2008, the finding was determined to be of very low safety significance because it was a design deficiency that did not result in the loss of functionality. The finding did not have any crosscutting aspects because it occurred more than three years ago and is not indicative of current licensee performance in that the licensee has significantly improved their design review process since the performance deficiency occurred (Section 4OA2). |
| Site: | South Texas  |
|---|---|
| Report | IR 05000498/2010003 Section 4OA2 |
| Date counted | Jun 30, 2010 (2010Q2) |
| Type: | Finding: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | J Dixon B Tharakan R Kopriva D Stearns W Walker B Tindell M Hayes T Buchanan N Hernandez C Denissen L Ricketson |
| INPO aspect | |
| ' | |
Finding - South Texas - IR 05000498/2010003 | |||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (South Texas) @ 2010Q2
Self-Identified List (South Texas)
| |||||||||||||||||||||||||||||||||||||||||||||||