05000316/LER-2007-001-01, Regarding As-found Local Leak Rate Tests Not Performed
| ML081760287 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 06/13/2008 |
| From: | Weber L Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP:NRC:2573-46 LER 07-001-01 | |
| Download: ML081760287 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 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)(ii)(B), Unanalyzed Condition 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) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3162007001R01 - NRC Website | |
text
INDIANA MICHIGAN POWER Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106 aep.com AEP:NRC:2573-46 10 CFR 50.73 June 13, 2008 Docket No. 50-316 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop O-Pl-17 Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 2 LICENSEE EVENT REPORT 316/2007-001-01 AS-FOUND LOCAL LEAK-RATE TESTS NOT PERFORMED In accordance with the criteria established by 10 CFR 50.73, Licensee Event Report System, the following report is being submitted:
LER 316/2007-001-01: "As-Found Local Leak Rate Tests Not Performed."
There are no commitments contained in this submittal.
Should you have any questions, please contact Mr. James M. Petro, Jr., Regulatory Affairs Manager, at (269) 466-2491.
Sincerely, Lawrence J. Weber Site Vice President JEN/rdw Attachment
- ý7&__ ao A i ge-,
U. S. Nuclear Regulatory Commission AEP:NRC:2573-46 Page 2 c:
J. L. Caldwell - NRC Region III K. D. Curry - AEP Ft. Wayne, w/o attachment INPO Records Center J. T. King - MPSC, w/o attachment MDEQ - WHMD/RPS, w/o attachment NRC Resident Inspector P. S. Tam - NRC Washington DC
'Itt).
I NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB:
NO. 3150-0104 EXPIRES 08/31/2010 (9-2007)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Donald C. Cook Nuclear Plant Unit 2 05000316 1 of 3
- 4. TITLE As-Found Local Leak Rate Tests Not Performed
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REVISION FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 10 28 2007 2007 001 01 06 13 2008
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
[] 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii) 5 0
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
[E 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL E] 20.2203(a)(2)(ii)
[- 50.36(c)(1)(ii)(A)
E] 50.73(a)(2)(iv)(A)
[E 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[] 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4) 000 I 0l 20.2203(a)(2)(iv)
E] 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B) 73.71(a)(5)
[I 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
H OTHER Specify in Abstract below El 20.2203(a)(2)(vi)
E 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D) or in (If more space is required, use additional copies of NRC Form (366A)
Conditions Prior to Event
Unit 2 was in a scheduled refueling outage and was in Mode 5.
Description of Event
On October 28, 2007, Donald' C. Cook Nuclear Plant (CNP) failed to perform the required as-found local leak rate tests (LLRT) prior to performing emergent maintenance that had the potential to affect the leak tightness of CNP Unit 2 Containment Isolation Valves. Originally identified were 2-WCR-942, Non-Essential Service Water (NESW) to Reactor Coolant Pump (RCP) No. 2 Motor Air Coolers Train A Containment Isolation Valve and 2-WCR-946, RCP No. 2 Motor Air Coolers NESW Outlet Train A Containment Isolation Valve. An extent of condition investigation noted that additional as-found LLRTs were not performed prior to maintenance performed September 26, 2007, on 2-WCR-922 and October 7, 2007,on 2-WCR-923; these are series Containment Isolation valves for NESW. This condition'prohibited by Technical Specifications (TS) was not recognized initially. This Licensee Event Report (LER) supplement adds these two additional valves which were not previously reported as extent of condition.
A maintenance planner was assigned to plan emergent maintenance activities for 2-WCR-942 and 2-WCR-946.
For each of the valves, the planner failed to include a task directing performance of an as-found LLRT: and did not include aI perec Jisite to validate as-found LLRT prior to performing maintenance. As a result, maintenari6ewoas performed :w'ithout having first.performed the as-found LLRT.
Additionally, the ipiping containing 2-WCR-922 and 2-WCR-923 valves in series was believed to have.beeh"plugged with sediment, a condition which would preclude as-found LLRTs. As a result, maintenance was performed on October 7, 2007, that identified that the apparent blockage was actually due to an internal valve component installed incorrectly (reversed finger plate) on 2-WCR-923 which prevented the valvefrom passing flow. The maintenance that was performed precluded performing the required as-found LLRT.
CNP's Containment Leakage Rate Testing Program, as directed by Surveillance Requirement (SR) 3.6.1.1, requires the conduct of as-found LLRTs. This is performed to validate containment integrity through that penetration if an accident condition would have occurred during the previous cycle of power operations.
The failure to meet SR 3.6.1.1 is reportable in accordance with the requirements of 10 CFR 50.73(a)(2)(i)(B),
Operation or Condition Prohibited by Technical Specifications.
Cause of Event
The cause of the 2-WCR-942 and 2-WCR-946 event can be attributed to human error due to inadequate validation of assumptions. The emergent work order tasks were created in an expeditious manner to ensure completion of the work within the known window of opportunity. The job planner understood that as-found LLRTs are required for these valves, but incorrectly assumed that the maintenance was required because the valves failed their as-found LLRTs.
Additionally, the planner identified work order tasks for performing routine, scheduled as-found LLRTs on these valves, and again incorrectly assumed that because these tasks existed, no other as-found LLRTs would need to be created.
(If more space is required, use additional copies of NRC Form (366A)
The cause of the 2-WCR-922 and 2-WCR-923 event was that, based on results of troubleshooting, the piping for these valves appeared to be blocked or plugged. Blocked piping would preclude any LLRTs, so maintenance was initiated to clear the piping. The maintenance identified a reversed finger plate on 2-WCR-923 rather than blocked piping. The reversed finger plate prevented 2-WCR-923 from opening. For this event, it was understood that the as-found testing would not be performed on 2-WCR-922 and 2-WCR-923 due to the apparent blockage, but not performing the as-found testing was not initially recognized as being a condition prohibited by TS. This was due to a mindset that an inability to perform the required testing, in this case due to apparent blockage, would make the condition (not performing the as-found testing) acceptable under program requirements.
Analysis of Event
As-found LLRTs were not performed prior to maintenance on these NESW system containment isolation valves:.
However, in the case of both the original and this LER supplement, the maintenance was not for repair of any seat leakage and not due to valve closure issues, such.that the valves were able at all times to perform their containment isolation function. As such,failure to properly implement the "as-found" LLRT test requirement had no impact on plant risk in terms of an increase in Core Damage Frequency or Large Early Release Frequency, or the consequences of design basis events.
The valves of concern, which were on an extended testing interval, have been returned to the nominal testing-.
interval as the missing as-found LLRTs will preclude meeting the procedure requirements for extended frequency., ý-,.
Post-maintenance as-left LLRTs were completed following the maintenance on the valves.
Corrective Actions
The Work Package Planner Training Program.(initial and recurring) will be modified to include focus on LLRT requirements.
Work Control planner templates have been enhanced to include verification of LLRT performed prior to any work on containment isolation valves.
Engineering procedures governing the conduct of the LLRT program will be revised to specify required actions for a missed LLRT, whether inadvertent or intentionally not performed due to system/component conditions.
2-WCR-923 was disassembled, properly repaired, and successfully tested.
Previous Similar Events
A search of the past three years identified one Licensee Event Report (LER) for a similar missed as-found LLRT surveillance:
05000316/2006-005-00 Failure to Comply with Technical Specification Surveillance Requirement 3.6.1.1 The corrective actions for the event documented in LER 05000315/2006-005-00 failed to prevent the events documented in this LER. This failure to prevent recurrence has been captured in CNP's Corrective Action Program.