ENS 43689
ENS Event | |
|---|---|
20:30 Oct 3, 2007 | |
| Title | Potential Unavailability of Two Way Radio System to Support Safe Shutdown |
| Event Description | In response to Self-Assessment Report SA014668 and preparation for the 2008 Triennial Fire Protection Inspection, a Fire Protection Improvement Plan implementation is in progress. Preliminary analysis of the major equipment, power supplies and cables associated with the two-way radio communication system (DCR-3341) indicates the potential for the plant two-way radio system to be adversely impacted and potentially unavailable to support post-fire safe shutdown operator actions and/or fire brigade fire fighting activities for a fire location in:
- Fire Zone AX-35 (Control Room and AC Equipment Room) - Fire Zone TU-22 (Turbine Room) at the mezzanine elevation just outside Battery Room 1B - Fire Zone TU-98 (Battery Room 1B) This review has identified discrepancies regarding the credited means of communication required for use by Operators in response to an Appendix R fire. The safe shutdown procedures E-O-06 and E-O-07, and the Manual Action Feasibility Study (Fire Protection Engineering Evaluation FPEE-003) only credit the plant two-way radio system. However, upper tier program documents (e.g., Fire Protection Program Plan, Appendix R Design Description) do not consistently contain the same requirements. For example, the Fire Plan, Rev 7, Section 12.9 requires both the 5-channel Gai-Tronics system between key shutdown locations AND the multi-channel portable radio communications equipped with repeaters and provided for use by the plant fire brigade shall be operable at all times. The Appendix R Design Description. Rev. 5 is silent on safe shutdown communications. It is not clear at this time whether the 5-channel Gai-Tronics should also be credited in the safe shutdown procedures. If so, then the cables supporting operation of the Gai-Tronics would need to be identified and located by fire zone to determine their availability in lieu of two-way radio communications for a fire in any of the three fire zones identified above. Until this is verified, the Appendix R timeline for achieving sate shutdown may not be able to be met. Therefore, this is reportable under 10 CFR 50.72 (b)(3)(V)(A), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A) shutdown the reactor and maintain it in a safe shutdown condition, (B) remove residual heat, (C) control the release of radioactive material, OR (D) mitigate the consequences of an accident. The licensee will notify the NRC Resident Inspector.
EN# 43689 provided notification that the Appendix R timeline for achieving safe shutdown may not be achievable due to potential loss of the credited two-way radio communication system due to fire and consequent need for face-to-face communications between the Operators. This position was adopted pending verification of the availability of the Gai-Tronics paging system. A subsequent engineering analysis of the major equipment, power supplies and cables associated with the Fire Protection/Appendix R two-way radio communication system, the Gai-Tronics plant paging system and the dedicated Emergency Gai-Tronics System, determined that adequate communications would have been available during a fire in the subject fire zones. Operators are familiar with and skilled in the use of the Gai-Tronics system as part of their job function. Interviews with on-shift Operators confirmed that operations would use the two-way radios; and if they failed, would then use the nearest Gai-Tronics handset station and then Emergency Gai-Tronics at specific locations for an Appendix R Dedicated Shutdown scenario. Where Operator manual actions are in close proximity to the Dedicated Shutdown panel, face-to-face communications would be achievable and timely. Consequently, the assumption of only face-to-face communications described in the Event Report would not have been necessary for all safe shutdown actions. Use of redundant communications systems (Gai-Tronics and Emergency Gai-Tronics) would have been available for fires in the subject fire zones such that the Appendix R safe shutdown time requirements would not have been significantly impacted. The loss of the two-way radio system for the identified fire zones would not have prevented the fulfillment of the safety function of systems that are needed to shut down the reactor and maintain it in a safe shutdown condition. As such, this condition is not reportable under 10CFR50.72(b)(3)(v)(A) as previously stated. Consequently, the notification made on 10/03/2007 (EN 43689) is hereby retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (Lipa). |
| Where | |
|---|---|
Kewaunee  Wisconsin (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor | |
| Time - Person (Reporting Time:+3.13 h0.13 days <br />0.0186 weeks <br />0.00429 months <br />) | |
| Opened: | Andrew Smolinski 23:38 Oct 3, 2007 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Nov 30, 2007 |
| 43689 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |