05000395/LER-2013-004, Regarding Spray System Relief Valve Failure to Lift at Required Setpoint Renders the Reactor Building Spray System Inoperable

Regarding Spray System Relief Valve Failure to Lift at Required Setpoint Renders the Reactor Building Spray System Inoperable

ML13275A138
Person / Time
Site:	Summer  (NPF-012)
Issue date:	09/30/2013
From:	Gatlin T South Carolina Electric & Gas Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 13-004-00
Download: ML13275A138 (4)

LER-2013-004, Regarding Spray System Relief Valve Failure to Lift at Required Setpoint Renders the Reactor Building Spray System Inoperable

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x)
3952013004R00 - NRC Website

text

Thomas D. Gatlin Vice President, Nuclear Operations 803.345.4342 A SCANA COMPANY September 30, 2013 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555

Dear Sir / Madam:

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS)

DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 LICENSEE EVENT REPORT (LER 2013-004-00)

RELIEF VALVE FAILURE TO LIFT AT REQUIRED SETPOINT RENDERS THE REACTOR BUILDING SPRAY SYSTEM INOPERABLE Attached is Licensee Event Report (LER 2013-004-00), for the Virgil C. Summer Nuclear Station. This report describes a relief valve that failed to lift at its required setpoint during Refueling Outage 20. This report is submitted in accordance with 10 CFR 50.73(a)(2)(i)(B).

Should you have any questions, please call Mr. Bruce Thompson at (803) 931-5042.

Very truly"ur Thomas D. Gatlin RLP/TDG/MM Attachment c:

K. B. Marsh S. A. Byrne J. B. Archie N. S. Carns J. H. Hamilton J. W. Williams W. M. Cherry V. M. McCree R. E. Martin NRC Resident Inspector QA Manager - M. N. Browne Paulette Ledbetter J. C. Mellette EPIX Coordinator K. M. Sutton INPO Records Center Marsh USA, Inc.

Maintenance Rule Engineer NSRC RTS (CR-13-02143)

File (818.07)

PRSF (RC-13-0153)

Virgil C. Summer Station - Post Office Box 88, Jenkinsville, SC. 29065 - F (803) 941-9776 I -T%.-

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 1013112013 (10-2010)

,Estimated

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3. PAGE Virgil C. Summer Nuclear Station Unit 1 05000 39S OF 3

4. TITLE Spray System Relief Valve Failure to Lift at Required Setpoint Renders the Reactor Building Spray System Inoperable

5. EVENT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY R

YEAR SEQUENTII D AY ER YA NUMBE DOCKET NUMBER 05000 07 30 2013 DOCKET NUMBER 05000 4

9. OPERATING MODE MODE 1

10. POWER LEVEL 100%

that apply)

LI 20.2201(b)

E] 20.2201 (d)

[]

20.2203(a)(1)

LI 20.2203(a)(2)(i)

[

20.2203(a)(2)(ii)

[]

20.2203(a)(2)(iii)

[]20.2203(a)(2)(iv)

[]20.2203(a)(2)(v)

E] 20.2203(a)(2)(vi)

[J 20.2203(a)(3)(i)

LI 50.73(a)(2)(i)(C) j 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)

F] 20.2203(a)(4) 50.73(a)(2)(ii)(B)

[]

50.36(c)(1)(i)(A)

E] 50.73(a)(2)(iii)

E] 50.36(c)(1)(ii)(A)

[]

50.73(a)(2)(iv)(A)

H 50.36(c)(2)

H 50.73(a)(2)(v)(A) 50.46(a)(3)(ii)

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

[

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

LI 50.73(a)(2)(v)(C)

[]

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

[]

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

El 50.73(a)(2)(vii)

E] 50.73(a)(2)(viii)(A)

E] 50.73(a)(2)(viii)(B)

[]

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

H 50.73(a)(2)(x) 73.71 (a) (4)

El 73.71 (a)(5)

El OTHER Specify in Abstract below or in I11. Safety Significance This condition had no notable safety consequences that were determined to impact the public or the plant. Taking the "B" train spray system out of service at the same time as "B" train Reactor Building Cooling Unit (RBCU) results in a very small change in risk as calculated by the Equipment Out of Service program. The delta Core Damage Frequency is 3.9E-07. The delta Large Early Release Frequency (LERF) is essentially zero (0.7% increase). The "B" train spray system and "B" train RBCU could both remain out of service for the entire year with only a very small increase in LERF.

IV. Corrective Actions

The valve was refurbished in RF-20. This activity required internal inspections, cleaning, and adjustment. Subsequently the valve was successfully tested three times prior to the relief valve being returned-to-service. As a result of this failed test, VCSNS revised the valve test frequency from every fourth refueling outage to every other refueling outage.

V. Previous Occurrences

No previous occurrences to this event have been identified.