05000315/LER-2012-002, For Donald C. Cook, Unit 1, Regarding Unit 1 Exceeded Technical Specification Time Limit to Shutdown
| ML12272A280 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 09/14/2012 |
| From: | Gebbie J Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP-NRC-2012-76 LER 12-002-00 | |
| Download: ML12272A280 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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 |
| 3152012002R00 - NRC Website | |
text
z INDIANA MICHIGAN POWERr A unit of American Electric Power Indiana Michigan Power One Cook Place Bridgman, MI 49106 IndianaMichiganPower.corm September 14, 2012 AEP-NRC-2012-76 10 CFR 50.73 Docket No. 50-315 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 1 LICENSEE EVENT REPORT 315/2012-002-00 UNIT 1 EXCEEDED TECHNICAL SPECIFICATION TIME LIMIT TO SHUTDOWN In accordance with the criteria established by 10 CFR 50.73, Licensee Event Report System, the following report is being submitted:
LER 315/2012-002-00: "Unit 1 Exceeded Technical Specification Time Limit to Shutdown."
There are no commitments contained in this submittal.
Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.
Sincerely, Joel P. Gebbie Site Vice President JEN/kmh Enclosure c:
LEReventst*Dinpo.orq (e-mail only)
J. T. King - MPSC, w/o enclosure S. M. Krawec - AEP Ft. Wayne, w/o enclosure MDEQ - RMD/RPS, w/o enclosure NRC Resident Inspector C. A. Casto - NRC Region III T.J. Wengart - NRC Washington DC g La~
NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES 10/31/2013 (10-2010)
, 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 1 05000-315 1 of 3
- 4. TITLE Unit 1 Exceeded Technical Specification Time Limit to Shutdown
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO.
05000 FACILITY NAME DOCKET NUMBER 07 19 2012 2012 002
- - 00 09 14 2012 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
El 20.2203(a)(3)(i)
El 5D.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
[]
20.2201(d)
El 20.2203(a)(3)(ii)
[I 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
[I 20.2203(a)(1)
El 20.2203(a)(4)
[I 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
[I 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
[I 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL [I
20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
E]
50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71 (a)(4) 050 [E 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
H 73.71 (a)(5)
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
OTHER Specify in Abstract below 20.2203(a)(2)(vi) 10 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D) or in
Cause of Event
Each of the two fuses blew due to different causes:
The apparent cause of one fuse failure was an internal low resistance on the splice connecting the 250 VDC cable [CBL3] to the associated dump valve solenoid [SOL], and a resulting ground from the cable to the junction box [JBX].
The apparent cause of the other fuse failure has been attributed to a transient ground. Investigation concluded through testing that the initial fault causing this fuse to blow was not a standing condition, and provides support that the cause can be attributed to a momentary or transient ground condition.
Analysis of Event
The failure that caused the loss of the automatic function associated with the SGSV dump valves on two steam generators did not result in any actual industrial, radiological or nuclear safety impact. However, as a result of exceeding the six hour limit, power was lowered in compliance with TS LCO 3.3.2 Condition I. Power reduction was stopped at 50% when enforcement discretion was granted to remain in Mode 1. While an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to remain in Mode 1 was granted to allow the necessary repairs, the repairs to both dump valves were completed using less than onehour of the additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that were granted. As such, the time spent in this condition was minimal.
To support the NOED, the assessment of safety significance and potential consequences of extending the TS completion times and operating while replacing the affected equipment concluded that granting the NOED would result in no significant increase in radiological risk to the public. Further, the requested NOED meets the criteria specified in Section B of the Inspection Manual Part 9900 for an operating plant. The request was based on the avoidance of an undesirable transient caused by the shutdown of the reactor as a result of forcing compliance with TS and thus minimizes the potential safety consequences and operational risks associated with plant shutdown.
The affected stop valves lost one of the two redundant trains necessary to automatically close the SGSVs.
However, because the redundant train of dump valves was operable, automatic and manual closure of.the two affected SGSVs could have still been achieved. The dump valves associated with the other two SGSVs were unaffected and remained operable.
Corrective Actions
Completed Corrective Actions On one of the 250 VDC control power circuits, the cable splice was replaced and the dump valve solenoid was replaced. On both of the 250 VDC control power circuits, the fuses were replaced.
Planned Corrective Actions
The cable splice on the circuit which was not replaced as a corrective action will be tested in place for a transient ground condition. Following that testing it will be removed, replaced and sent to a vendor for additional failure testing.
Previous Similar Events
A review of Licensee Event Reports for the past three years found no similar events.