05000266/LER-2010-005, For Point Beach Regarding Improper Administrative Controls for HELB Barriers
| ML110530152 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/18/2011 |
| From: | Meyer L Point Beach |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC 2011-0022 LER 10-005-00 | |
| Download: ML110530152 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) |
| 2662010005R00 - NRC Website | |
text
February 18,201 1 POINT BEACH NRC 201 1-0022 10 CFR 50.73 U. S. Nuclear Regulatory Commission AWN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Unit 1 Dockets 50-266 and 50-301 License Nos. DPR-24 and DPR-27 Licensee Event Report 2661201 0-005-00 Improper Administrative Controls for Breach of HELB Barriers Enclosed is Licensee Event Report (LER) 2661201 0-005-00 for Point Beach Nuclear Plant (PBNP), Units 1 and 2. This LER documents improper controls used while breaching high energy line break (HELB) barriers. Pursuant to 10 CFR 50.73(a)(2)(ii)(B), and 10 CFR 50.73(a)(2)(v)(A) and (D), the event is reportable as an unanalyzed condition and a condition that could have prevented fulfillment of the safety function of systems that are needed to shutdown the reactor and maintain it in a safe shutdown condition or mitigate the consequences of an accident.
This submittal contains no new or revised regulatory commitments.
If you have questions or require additional information, please contact Mr. James Costedio at 9201755-7427.
Very truly yours, NextEra Energy Point Beach, LLC Site Vice President Enclosure cc:
Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW NextEra Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241
C] 20.2203(a)(3)(i)
C] 50973(a)(2)(i)(C) 50.73(a)(2)(vii)
C] 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)
C] 50.73(a)(2)(viii)(A) 20.2203(a)(4)
El 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B)
C] 50.36(c)(l )(i)(A)
C] 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
C] 50.36(c)(l)(ii)(A)
C] 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) equipment within the adjacent room.
A three-year review was conducted to determine the extent of condition of the potential barrier breaches. The results revealed additional instances where HELB barriers had been improperly controlled and the barrier had been rendered inoperable. A causal evaluation determined that the administrative procedure governing HELB barriers was not consistent with industry standards and did not contain applicable regulatory guidance. An analysis for safety significance is in progress.
This 60-day licensee event report is being submitted in accordance with the requirements of 10 CFR 50.73(a)(2)(ii)(B), as an unanalyzed condition and 10 CFR 50.73(a)(2)(v)(A) and (D) as a condition that could have prevented fulfillment of the safety function of systems that are needed to shutdown the reactor and maintain it in a safe shutdown condition or mitigate the consequences of an accident. The event constitutes a safety system functional failure.
NCR FORM 366 (1 0-201 0)
RC FORM 366A U.S. NUCLEAR REGULATORY COMMlSSlOF 0-201 0)
LICENSEE EVENT REPORT LER)
CONTINUATION SHEE 1(
Point Beach Nuclear Plant 1 05000266 11 2010 - 005 00 11 Page 2 of 3
- 1. FACILITY NAME
- 6. LEU NUMBER
Event Description
YEAR During the spring of 2010 NextEra identified that there were several instances where barriers were not being properly controlled and had been breached during maintenance and modification activities.
Specifically, NextEra identified that high energy line break (HELB) barriers had been improperly controlled while the barriers were open for other than normal ingress and egress. If a HELB had occurred while the barriers had been breached, the condition could have adversely affected safety-related equipment contained in the adjacent room.
The station's administrative program in place at the time of these past events was determined to be inconsistent with industry standards and applicable regulatory guidance. Furthermore, the program did not include an analysis of postulated HELB effects on safety-related equipment, during barrier breaches.
SEQUENTIAL NUMBER This 60-day licensee event report is being submitted in accordance with the requirements of 10 CFR 50.73(a)(2)(ii)(B), as an unanalyzed condition, and 10 CFR 5OS73(a)(2)(v)(A) and (D) as a condition that could have prevented fulfillment of the safety function of systems that are needed to shutdown the reactor and maintain it in a safe shutdown condition or mitigate the consequences of an accident. The event constitutes a safety system functional failure.
REVISION NUMBER
Event Analysis
A three-year historical review of the station log was conducted to identify HELB breach occurrences.
NextEra determined that the north control room door was prevented from closing for lock replacement approximately every six (6) weeks over the duration of the review. The data contained in the station log was further verified by security logs that monitored the status of this door during the potential breach. The north control room door is a HELB barrier. The door would mitigate the consequences of a potential HELB event in the turbine building by maintaining the normal control room environment.
There were other additional identified instances of HELB barriers being breached during the review period.
Where possible, the station log information was further verified by security logs that monitored the status of the barrier during the potential breach.
Based upon work practices that implemented administrative procedure guidance at the time of the events, NextEra conservatively assumed that the above described barriers were prevented from closing by mechanical means. Therefore, a harsh environment could have existed in the areas protected by the barrier had a HELB event occurred during the period of time the barrier was prevented from closing. The equipment potentially affected was dependent upon the specific barrier that was breached for the given area.
Preventing HELB barriers from closing created a condition where the barriers were degraded relative to protecting both the safety-related and environmentally-qualified equipment contained in the area. A HELB barrier may be opened for routine ingress and egress with no effect on the HELB barrier's ability to perform its function. Since the barriers were prevented from closing, the barriers were not open for routine ingress and egress. An analysis had not been performed to determine whether the equipment on the other side of the breached barrier would become subject to a harsh environment had a HELB occurred.
A follow-up adverse trend evaluation was performed of documented instances of barrier breaches. The purpose of the evaluation was to determine if other programs (such as fire barriers) had sufficient administrative controls in place to prevent an improper breach of the required barrier. The results of the evaluation determined that corrective actions were appropriate to resolve the identified extent of condition.
Safety Significance
A historical review concluded when the barriers were prevented from closing there was no actual loss of a safety-related system, structure or component (SSC). Overall, HELB events are low-frequency occurrences.
These events would have to cause systems required to mitigate a postulated HELB to be rendered non-functional in order to result in substantive safety consequences. The probability of a main steam line break occurring during the individual short time periods the HELB barriers were open is very low. Therefore, the safety significance of the individual events is low.
Analyses are in progress to determine the overall safety significance of the HELB barrier breaches and the impact on safety-related equipment protected by the barrier. This licensee event report will be supplemented when that analysis has been completed.
Cause
The cause of the condition was that HELB programmatic requirements did not incorporate applicable industry guidance. The program permitted barriers to be prevented from closing and did not require an analysis of postulated HELB effects on safety-related equipment during barrier breaches. These program deficiencies led to the effects of a potential HELB event not being appropriately considered,
Corrective Actions
The following corrective actions were taken:
o The HELB administrative procedure was revised to reflect applicable industry guidance.
o Pending work packages for HELB related work were updated with revised HELB requirements.
Previous Occurrences
None Failed Components Identified:
None