05000321/FIN-2006006-02
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Finding | |
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| Title | Inadequate Testing of Remote Shutdown Panel Transfer Switches |
| Description | The team identified a URI associated with inadequate testing of RSDP Transfer switches in that the testing did not verify proper isolation of all switch contact circuits between the MCR and the RSDP as required for Appendix R. Description: The licensees SSD strategy relied on the remote shutdown system to shutdown both units in the event of a fire in the MCR. Unit 1 has six RSDPs and Unit 2 has one. Prior to leaving the MCR, the operators will scram the reactor, close the main steam isolation valves and shutdown both units utilizing the RSDP. At these panels, the operators will transfer control functions from various systems from the MCR to the RSDP. Several switches are utilized to accomplish this transfer. The transfer switches are designed not only to allow control of the components from the remote shutdown panels, but also to isolate control electrically from the MCR (i.e., Appendix R function). TS Surveillance Requirement (SR) 3.3.3.2.2 requires verification by test every 24 months that each required control circuit and transfer switch is capable of performing its intended safety function. This is implemented by Surveillance Procedure 34SV-C82-003-1, Remote Shutdown Panel Function Checks, as well as other surveillance procedures listed in the Attachment, and consists of placing the RSDP transfer switches to emergency and verification that an annunciator comes on in the MCR as well as operating the affected equipment from the remote shutdown panel. Upon review of completed surveillance test records and post modification testing, the team determined that 9 out of 19 switches on Unit 1 and all the switches on Unit 2 were not properly tested to meet Appendix R requirements or TS. The functional testing of the transfer switches on the remote shutdown panel did not verify proper electrical isolation of the transfer circuits between the MCR and the RSDP. The team found that not all the switch contacts were being verified. In reviewing the history of the switches, the inspectors found that several Condition Reports had been initiated due to switch failures on Unit 1. The corrective actions required the replacement of the Unit 1 switches. In addition, the surveillance interval had been increased from a 24 month frequency to every six months. The team found that in October 2004, CR 2004108804 had been initiated to respond to a question from NRC regarding the requirement to functionally test the isolation function of the transfer switch. The response to CR 2004108804 was included in AI 2004203791 and was closed by corporate licensing without communicating the information in the response to the plant site. The response specified that the isolation function shall be tested per TS SR 3.3.3.2.2 which requires verification that the transfer switch is capable of performing its intended safety function every 24 months. It also specified that this testing should be performed when installing a new switch. Because the information had not been communicated to the site, the surveillance test procedures for units 1 and 2 had not been revised, and 9 of 19 new replacement switches were installed on Unit 1 without proper post-modification testing to verify the isolation function of all transfer switch contacts between the MCR and the RSDP. After the team raised this concern, the licensee initiated CR 2006104675 to address the fact that the AI response from corporate did not get communicated to the site and to further review the regulatory testing requirements for the RSDP transfer switches. A list of the specific switches that were not tested are in the Attachment to the report. Based on the above, this issue is unresolved pending review of the completed surveillance test results or the results of the licensees re-analysis of the regulatory testing requirements for the switches. Since this issue affects both units it will be identified as URI 05000321, 366/2006006-002, Inadequate Testing of Remote Shutdown Panel Transfer Switches. |
| Site: | Hatch  |
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| Report | IR 05000321/2006006 Section 1R05 |
| Date counted | Jun 30, 2006 (2006Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | D Mas Penaranda E Lea G Macdonald G Wiseman N Merriweather R Fanner R Rodriguezs Viasj Hickey J Quinone-Navarro P Niebaum |
| INPO aspect | |
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Finding - Hatch - IR 05000321/2006006 | |||||||||||||||||
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Finding List (Hatch) @ 2006Q2
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