05000278/LER-2005-004, Re Laboratory Analysis Identifies Safety Relief Valve Set Point and Performance Deficiencies

Re Laboratory Analysis Identifies Safety Relief Valve Set Point and Performance Deficiencies

ML053270220
Person / Time
Site:	Peach Bottom
Issue date:	11/21/2005
From:	Grimes J Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 05-004-00
Download: ML053270220 (5)

LER-2005-004, Re Laboratory Analysis Identifies Safety Relief Valve Set Point and Performance Deficiencies

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
2782005004R00 - NRC Website

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Exelon Nuclear Telephone 717.456.7014 Nuclear Peach Bottom Atomic Power Station www.exeloncorp.com 1848 Lay Road Delta, PA 17314-9032 1 OCFR 50.73 November 21, 2005 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station (PBAPS) Unit 3 Facility Operating License No. DPR-56 NRC Docket No. 50-278

Subject:

Licensee Event Report (LER) 3-05-04 This LER reports a condition prohibited by Technical Specifications involving four Safety Relief Valves (SRVs) that did not meet their + 1 % set point tolerance when tested in the laboratory. Additionally, one other SRV, when tested, did not properly re-seat during testing. In accordance with NEI 99-04, the regulatory commitment contained in this correspondence is to restore compliance with the regulations. The specific methods that are planned to restore and maintain compliance are discussed in the LER. If you have any questions or require additional information, please do not hesitate to contact us.

Sincerely, Joseph P. Grimes Plant Manager Peach Bottom Atomic Power Station JPG/djf/CR 381079/ 381063 Attachment cc:

PSE&G, Financial Controls and Co-owner Affairs R. R. Janati, Commonwealth of Pennsylvania INPO Records Center S. Collins, US NRC, Administrator, Region I R. I. McLean, State of Maryland US NRC, Senior Resident Inspector CCN 05-14101

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007

(-2004)

, the NRC may not conduct or sponsor, and a person Is not required to respond to, the Information digits/characters for each block) collection.

3. PAGE Peach Bottom Atomic Power Station Unit 3 05000 278 1 OF 4

4. TITLE Laboratory Analysis Identifies Safety Relief Valve Set Point and Performance Deficiencies

5. EVENT DATE

6. LER NUMBER

=

7. REPORT DATE

8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEUMENTA REV MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 10 2

2005 05 04 -

0 11 22 2005 05000

9. OPE MTING MODE 1.THIS REPORT IS SUBMITTED PURSUANTTO THE REOUIREMENTS OFI 1CFR§: (Check all thatapply) o 20.2201(b) 0 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C)

ED 50.73(a)(2)(vii) 0 20.2201(d)

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

El 50.73(a)(2)(viii)(A) 0 20.2203(a)(1)

El 20.2203(a)(4)

El 50.73(a)(2)(ii)(B)

C 50.73(a)(2)(viii)(B)

Co 20.2203(a)(2)(i) 0 50.36(c)(1)(i)(A)

E 50.73(a)(2)(iii)

El 50.73(a)(2)(ix)(A)

10. POWER LEVEL El 20.2203(a)(2)(ii)

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

El 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x)

El 20.2203(a)(2)(iii)

El 50.36(c)(2)

El 50.73(a)(2)(v)(A) 0 73.71(a)(4) o 20.2203(a)(2)(iv) a 50.46(a)(3)(ii)

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

El 73.71 (a)(5) 100 0 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C)

El OTHER 0

20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) 0l 50.73(a)(2)(v)(D)

Specify In Abstract below or In (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)

Cause of the Event

The cause of the four SRVs being outside of their allowable as-found set points is due to set point drift. A historical review of SRV as-found test set points indicates that approximately 20% of valves tested over time do not meet the + I% Technical Specification set point.

Concerning the failure of SRV S/N 193 to re-close, laboratory failure analysis identified that the main valve (EIIS: V) disc (third stage) had not properly re-seated when closing. Preliminary analysis indicates that a misalignment of the main valve disc spring is the likely cause. This valve was last refurbished in February 2001. Finalization of the causal analysis is in progress.

Corrective Actions

The five SRVs were replaced with different SRVs for the 16eh Unit 3 operating cycle.

Additional assessment and appropriate corrective actions concerning SRV refurbishment vendor work practices will be further assessed as part of the Corrective Action Program.

Previous Similar Occurrences There was one previous LER identified involving the failure of an SRV to re-close following automatic operation. LER 2-03-04 identified an event on Unit 3 that involved a failure of SRV S/N 18 to re-close. A laboratory failure analysis determined that tightly adhered foreign material on the pilot valve disc may have prevented the first stage pilot valve disc from properly re-closing. Corrective actions identified through the Corrective Action Program included the improved decontamination, cleaning, and examination processes.

These corrective actions are still in progress and primarily involved the first stage piston work practices.

Therefore, these corrective actions would not be expected to have prevented the SRV S/N 193 failure to re-close concern.