05000461/LER-2011-004, Regarding Automatic Reactor Scram During Removal of Main Generator

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Regarding Automatic Reactor Scram During Removal of Main Generator
ML12031A145
Person / Time
Site: Clinton Constellation icon.png
Issue date: 01/12/2012
From: Noll W
Exelon Nuclear
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
SRRS 5A.108, U-604048 LER 11-004-00
Download: ML12031A145 (4)


LER-2011-004, Regarding Automatic Reactor Scram During Removal of Main Generator
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
4612011004R00 - NRC Website

text

Exelon.

Nuclear Clinton Power Station 8401 Power Road Clinton, IL 61727-9351 U-604048 10 CFR 50.73 January 12, 2012 SRRS 5A.108 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461

Subject:

Licensee Event Report 2011-004-00 Enclosed is Licensee Event Report (LER) No. 2011-004-00: Automatic Reactor Scram During Removal of Main Generator. This report is being submitted in accordance with the requirements of 10 CFR 50.73.

There are no regulatory commitments contained in this report.

Should you have any questions concerning this report, please contact A. Khanifar, at (217)-

937-3800.

Respcf1 William G. Noll Site Vice President Clinton Power Station RSF/blf

Enclosures:

Licensee Event Report 2011-004-00 cc:

Regional Administrator - NRC Region III NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety - IEMA Division of Nuclear Safety

I Y

NNRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)

, the NRC may sfor each block) not conduct or sponsor, and a person is not required to respond to, the digits/characters finformation collection.

3. PAGE Clinton Power Station, Unit 1 05000461 1 OF 3
4. TITLE Automatic Reactor Scram During Removal of Main Generator
5. EVENT DATE
6. LER NUMBER
7. REPORT DATE
8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MSEUENTIAL REV MONTH DAY YEAR N/A N/A MONH DY YAR EAR NUMBER NO.

FACILITY NAME DOCKET NUMBER 11 29 2011 2011 004 00 01 12 2012 N/A N/A

9. OPERATING MODE
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)

El 20.2201(b)

[I 20.2203(a)(3)(i)

[I 50.73(a)(2)(i)(C)

El 50.73(a)(2)(vii) 1 El 20.2201(d)

El 20.2203(a)(3)(ii) 0l 50.73(a)(2)(ii)(A)

El 50.73(a)(2)(viii)(A)

El 20.2203(a)(1)

El 20.2203(a)(4) 0l 50.73(a)(2)(ii)(B)

El 50.73(a)(2)(viii)(B)

El 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 20.2203(a)(2)(ii)

El 50.36(c)(1)(ii)(A)

[D 50.73(a)(2)(iv)(A)

El 50.73(a)(2)(x)

El 20.2203(a)(2)(iii)

El 50.36(c)(2)

El 50.73(a)(2)(v)(A)

El 73.71(a)(4) 016 20.2203(a)(2)(iv)

El 50.46(a)(3)(ii)

El 50.73(a)(2)(v)(B)

El 73.71(a)(5)

El 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A)

El 50.73(a)(2)(v)(C)

[E OTHER El 20.2203(a)(2)(vi)

El 50.73(a)(2)(i)(B)

El 50.73(a)(2)(v)(D)

Specify in Abstract below or in Issue Report 1295617 was initiated to evaluate this event.

C. CAUSE OF EVENT

The cause of this event has been determined to be the failure to replace or refurbish the BVD card prior to its Mean Time Between Failure (MTBF) lifetime, resulting in the card failure. A MTBF analysis completed following this event concluded that the MTBF for the BVD card is 20 years. The card had been in service for 24 years prior to failure.

The BVD card was not identified as a critical component during the 2001 Plant Material Condition Excellence Initiative (PMCEI) assessment and 2007 Performance Centered Maintenance (PCM) assessment, and therefore, was not reviewed for maintenance strategy.

C. SAFETY CONSEQUENCES

This event is reportable under the provisions of 10 CFR 50.73 (a)(2)(iv)(A) due to a valid actuation of the Reactor Protection System [JC] while the reactor was critical.

The actuation of the Reactor Protection System placed the plant in a safe and stable condition. There were no plant safety limits exceeded, and no other Engineered Safety Feature (ESF) actuations, and risk significance was low. Safety related systems functioned correctly in response to this event with critical plant parameters remaining within the bounds of plant design, Technical Specifications, Updated Safety Analysis Report, Offsite Dose Calculation Manual, and Core Operating Limits Report. The affected system (SBPC System) is non-safety related.

No loss of safety function occurred during this event.

E.

CORRECTIVE ACTIONS

The failed BVD card (B channel) and the A channel BVD card were replaced during the refueling outage with new cards that were tested with satisfactory results.

Periodic 16-year replacement refurbishment PMs are being established for the A and B BVD cards in the SBPC system.

The SBPC System is being reviewed to ensure that critical cards have been identified and PMs are established as needed.

F. PREVIOUS OCCURRENCES

A review of reactor scrams over the past 10 years did not identify any events occurring as a result of the same

cause

G. COMPONENT FAILURE DATA

Component Description:

Circuit Board Assembly, Bypass Valve Demand Manufacturer Nomenclature Model General Electric N/A 30-992107-002 Mfg. Part Number N/A