05000456/FIN-2011005-03
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Finding | |
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| Title | Failure to Submit Licensee Event Report Per 10 CFR 50.73(a)(2)(vii) |
| Description | A Severity Level IV NCV of 10 CFR 50.73(a)(2)(vii) was identified by the inspectors when the licensee failed to submit a LER within 60 days after identifying instances in which a single cause (or condition) would cause two safety-related instrument channels to become inoperable in a single system designed to shutdown the reactor and maintain it in a safe shutdown condition. On March 8, 2011, the licensee identified a non-conservative assumption used in the stations Turbine Building High Energy Line Break (HELB) analysis of record in that the calculations were not updated for a historic power uprate. On March 14, 2011, the station completed an Operability Evaluation that examined how a HELB in the Turbine Building could affect safety-related equipment since many safety-related rooms had ventilation connections to the Turbine Building and shared a barrier wall with the Turbine Building. One of the errors identified by the licensee was associated with non-conservative HELB temperature and pressure parameters used in determining break flows. The licensee concluded that the higher break flows did not affect the operability of the safety-related rooms in a normal configuration, but concluded that the presence of open equipment rollup doors for the ESF Switchgear Rooms and MEERs could cause unacceptable temperatures. Therefore, the station instituted compensatory actions to control these rollup doors shut with equipment status tags when operating in Modes 1-4. On April 7, 2011, the inspectors identified that the station did not have any plans to review 10 CFR 50.73 reportability requirements regarding this issue. The inspectors notified the licensee that they had personally observed large breakers being moved through the rollup doors within the past 3 years. Based on these observations and conclusions reached in the operability determination, the inspectors specifically questioned if these conditions required the submittal of an LER. The station entered the inspectors observations into the CAP and created an assignment to review past reportability in IR 1199223. This LER evaluation assignment had an original due date of May 9, 2011, but the due date was later changed to July 29, 2011, based upon an on-going review to update the HELB model. The July 29, 2011 due date was also later changed to October 31, 2011 because the HELB model required substantially more work that originally believed. On October 31, 2011, the licensee completed the CAP assignment and concluded that with the Division 11 (or Division 21) Miscellaneous Electric Equipment Room (MEER) rollup door(s) open and the unit(s) operating in Modes 1-4, there was reasonable doubt that the safety-related instrument inverters inside of these rooms would have remained functional in the event of a concurrent HELB on the 451 elevation of the Turbine Building. This would have impacted operation of Instrument Bus 111 and 113 (or Instrument Bus 211 and 213). Based on this conclusion, and a formal review of when the associated rollup doors had been open within the past 3 years, the licensee concluded that four events were reportable under 10 CFR 50.73(a)(2)(vii). These events represented instances in which a Turbine Building HELB would have caused two safety-related instrument channels to become inoperable in a single system designed to shutdown the reactor and maintain it in a safe shutdown condition. Furthermore, the licensee concluded that the October 31, 2011, discovery marked the start of the 60-day reporting requirement specified in the regulations. The inspectors reviewed the reportability aspects associated with this issue from the March 8, 2011, date when the issue was first discovered and treated as an adverse condition affecting the operability of equipment through the time the LER was submitted to the NRC on December 22, 2011. The inspectors reviewed the NRCs event reporting guidelines contained in NUREG-1022, Revision 2, Event Reporting Guidelines 10 CFR 50.72 and 10 CFR 50.73, and discussed the report timeliness with NRC Office of Nuclear Reactor Regulation (NRR) experts. The inspectors concluded that the discovery date should have started when the licensee lost reasonable expectation that the equipment in question was not operable with the rollup doors open and the licensee understood that the doors had been opened within the past 3 years. Based on discussions with station staff, the licensee should have reported this event within 60 days of March 14, 2011. The licensee entered this issue into their CAP as IR 1299906. The inspectors determined that the failure to report this LER in accordance with NRC regulations was a performance deficiency. Specifically, the licensee should have created a CAP assignment to review the 10 CFR 50.73 reportability aspects of this issue without prompting from the inspectors and should have reported the issue in a timely manner. This violation had the potential to impact the regulatory process based upon the generic communication that LERs serve, the required Reactor Oversight Process (ROP) reviews that the NRC perform on all LERs, and the potential impact on licensee performance assessment. Since the issue impacted the regulatory process, it was dispositioned through the TS process. The inspectors determined that this issue was a Severity Level IV violation based on a similar example referenced in Supplement I, Example D.4, of the NRC Enforcement Policy. The inspectors evaluated the actual non-conforming technical condition through the ROP. The inspectors determined that the issue was licensee-identified and a violation of 10 CFR 50, Appendix B, Criterion III, Design Control. This issue is described in Section 4OA7 of this report. Reactor Oversight Process cross-cutting aspects do not apply to traditional enforcement issues or licensee-identified ROP findings of very low safety significance, therefore, none was identified. : Title 10 CFR 50.73(a), Reportable Events, required, in part, that The holder of an operating license under this part or a combined license under Part 52 of this chapter (after the Commission has made the finding under 52.103(g) of this chapter) for a nuclear power plant (licensee) shall submit a LER for any event of the type described in this paragraph within 60 days after the discovery of the event. In addition this section of the code requires that, Unless otherwise specified in this section, the licensee shall report an event if it occurred within 3 years of the date of discovery regardless of the plant mode or power level, and regardless of the significance of the structure, system, or component that initiated the event. Title 10 CFR 50.73(a)(2)(vii) described event(s) where a single cause or condition caused at least one independent train or channel to become inoperable in multiple systems or two independent trains or channels to become inoperable in a single system designed to: (A) Shutdown the reactor and maintain it in a safe shutdown condition; (B) Remove residual heat; (C) Control the releases of radioactive material; or (D) Mitigate the consequences of an accident. Contrary to the above, the licensee failed to report two Unit 1 and two Unit 2 conditions in which a Turbine Building HELB would have rendered two independent safety-related instrument channels inoperable in a single system designed to safely shutdown the reactor and maintain it in a safe shutdown condition within 60 days from the date when the condition was discovered. This information was known or available since March 14, 2011, but was not reported until December 22, 2011. Corrective actions included submitting an LER to the NRC on December 22, 2011. Because this violation was entered into the licensees CAP as IR 1299906, it is being treated as a Severity Level IV NCV, consistent with Section 2.3.2 of the NRC Enforcement Policy. Corrective actions included the issuance of LER 05000456/2011-004-00 on December 22, 2011. |
| Site: | Braidwood  |
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| Report | IR 05000456/2011005 Section 1R15 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | TEV: Severity level IV |
| cornerstone | Miscellaneous |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | A Dunlop A Garmoe B Bartlett B Palagi E Duncan J Benjamin J Nance M Learn M Perry R Jicklin T Go V Megani |
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Finding - Braidwood - IR 05000456/2011005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Braidwood) @ 2011Q4
Self-Identified List (Braidwood)
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