ML18153A883

LER 94-003-00:on 940204,hole in Recirculating Spray HX Svc Water Outlet Piping Identified.Caused by Failure of Coal Tar Epoxy Coating.Piping Inspected & Will Be Pressure Tested Per Station procedures.W/940304 Ltr

ML18153A883
Person / Time
Site:	Surry
Issue date:	03/04/1994
From:	Kansler M VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
94-137, LER-94-003-01, LER-94-3-1, NUDOCS 9403140238
Download: ML18153A883 (6)

Text

e 10CFR50.73 Vn-ginia Electric and Power Company Surry Power S1ati.on P.O.Box:315 Suny, Vu-ginia. 23883 March 4, 1994 U.S. Nuclear Regulatory Commission Serial No.: 94-137 Document Control Desk SPS:JDK Washington, D. C. 20555 Docket No.: 50-280 License No.: DPR-32

Dear Sirs:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Unit 1.

REPQRrNQMBER 50-280/94-003-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be forwarded to the Management Safety Review Committee for its review.

Very truly yours, Enclosure cc: Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 M. W. Branch NRC Senior Resident Inspector Surry Power Station

/!\. 'l, 940314023B 940304 PDR ADOCK 05000280 s PDR

-jvtd I I

NRC FORM 366 e . U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COUECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF (See reverse for required number of digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3)

Surrv Power Station. Unit 1 05000 - 280 1 OF 5 TITLE (4)

Hole in Recirculating Spray Heat Exchanger Service Water Outlet Piping EVENT DATE (5) LER NUMBER (6 REPORT NUMBER (7) OTHER FACILITIES INVOLVED (8 FACILITY NAME DOCKET NUMBER SEQUENTIAL REVISION MONTH DAY YEAR YEAR MONTH DAY YEAR NUMBER NUMBER 05000 FACILITY NAME DOCKET NUMBER 02 04 94 94 .. 003 ..

00 03 04 94 05000 OPERATING N THIS REPORT IS SUBMITIED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more (11 MODE (9) 20.402(b) 20.405(c) 50.73(a) (2) (iv) 73.71(b)

POWER 20.405(a)(1 )(i) 50.36(c)(1) 50. 73 (a)(2)(v) 73.71 (c)

LEVEL (10) 000 20.405(a) (1) (ii) 50.36(c) (2) 50.73(a)(2)(vii) OTHER 20.405(a)(1)(iii) 50. 73 (a)(2)(i) 50.73(a)(2)(viii)(A) (Specify in Abstract l!f below and in Text, NRC 1

I' j!jl1lillllll\lI!.II 20.405(a)(1 )(iv) X 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) Form 366A) 20.405 (a)( 1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER 12)

NAME TELEPHONE NUMBER (Include Area Code)

M. R. Kansler, Station Manager (804) 357-3184 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER TO NPRDS TO NPRDS I

SUPPLEMENTAL REPORT EXPECTED 14) EXPECTED MONTH DAY YEAR YES SUBMISSION NO (II yes, complete EXPECTED SUBMISSION DATE) DATE (15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On January 27, 1994, with Unit 1 at Cold Shutdown for the Cycle 12 refueling outage, a Service Water (SW) flow test was performed on one train of the Recirculation Spray System heat exchangers (RSHXs). During subsequent inspections of the 24 inch SW piping for the RSHXs, a small hole was discovered in an elbow on the SW outlet piping of RSHX B. This piping is in containment and provides a membrane barrier between the outside and containment atmospheres. A second barrier exists at the closed SW inlet and outlet motor operated isolation valves located outside containment. Since the unit was at cold shutdown, the recirculation spray system and containment integrity were not required. A Deviation Report was submitted and an evaluation of the potential leakage path from containment was performed. The evaluation determined that leakage through the hole would have been in excess of the 10CFRSO Appendix J limits. On February 4, 1994, it was determined that this condition was reportable pursuant to 10CFR50.72(b)(2)(i). A four hour non emergency report was made at 1748 hours0.0202 days <br />0.486 hours <br />0.00289 weeks <br />6.65114e-4 months <br />.

Inspection of the Unit 1 SW outlet piping for each RSHX has been completed. No other areas of piping below code allowable wall thickness were found. RSHX B SW outlet piping elbow will be replaced prior to unit startup.

This event is being reported pursuant to 10CFRSO. 73(a)(2)(ii).

NRC FORM 366 (5-92)

e e NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION ANO RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR TEXT CONTINUATION REGULATORY COMMISSION, WASHINGTON, QC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (315CHJ104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (I) PAGE (3)

SEQUENTIAL REVISION YEAR NUMBER NUMBER Surry Power Station, Unit 1 05000-280 2 OF 5 94 - 003 - 00 TEXT /// more space is required, use additional copies of NRC Form 356A) (17)

1.0 DESCRIPTION

OF THE EVENT On January 27, 1994, with Unit 1 at Cold Shutdown for the Cycle 12 refueling outage, a Service Water (SW) flow test was performed on one train of the Recirculation Spray System heat exchangers (RSHXs)[EIIS-BE-HX]. During subsequent inspections of the 24 inch SW piping [EIIS-BI-PSP] for the RSHXs, a small hole was discovered in an elbow on the SW outlet piping of RSHX B. This piping is in containment and provides a membrane barrier between the outside and containment atmospheres.

Additionally, normally closed SW inlet and outlet motor operated isolation valves (MOVs) are provided outside containment. Since the unit was at cold shutdown, the Recirculation Spray System (RS) and containment integrity were not required. A Deviation Report (DR) was submitted and an evaluation determined that the leakage through the hole would have been in excess of the 10CFRSO Appendix J limits. At 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on February 4, 1994, a determination was made based on the evaluation that this condition was reportable pursuant to 10CFR50.72(b)(2)(i). A four hour non-emergency report was made at 1748 hours0.0202 days <br />0.486 hours <br />0.00289 weeks <br />6.65114e-4 months <br />.

This event is being reported pursuant to 10CFR50.73(a)(2)(ii).

2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS Four RSHXs (two per train) are located in containment (one train provides 100% of the required flow) and have a two barrier arrangement for containment isolation. One barrier is provided by the piping membrane and the other by SW inlet and outlet isolation MOVs valves located outside containment. The SW isolation MOVs are normally closed receiving an automatic open signal in the event of a design basis accident.

I I

The RS system provides cooling spray to assist in returning the *I containment environment to subatmospheric conditions within the first .,

hour of a design basis accident. Since containment atmosphere would be at a higher pressure than the SW in the pipe for a portion of the first hour, the hole in the piping membrane represents a pathway for radioactivity to leak outside containment.

NRC FORM 366A (5-92)

e e NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB NO. 3150-0104

, (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION

'AND RECORDS MANAGEMENT BRANCH (MNBB n14), U.S. NUCLEAR TEXT CONTINUATION REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503, FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (S) PAGE (3)

SEQUENTIAL

• REVISION VEAR NUMBER NUMBER Surry Power Station, Unit 1 05000 -280 3 OF 5 94 -

• 003 00 TEXT (II more space is reqv,red, use addit;onli copies of NRC Form 3664) (17) 2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS (Cont,)

The SW outlet piping for each RSHX is provided with a radiation monitor to detect radioactive leakage. The monitors have alarms and indications in the main control room which allow the operators to identify a leaking heat exchanger. Emergency and annunciator response procedures provide guidance for isolating the heat exchanger utilizing the SW inlet and outlet isolation MOVs. These MOVs can be closed from the main control room.

During power operations the MOVs were operable and would have provided isolation in the event of an accident. The outlet piping for the other three heat exchangers was examined and determined to exceed minimum code wall thickness requirements.

Since the outside isolation SW MOVs were operable and could isolate a leak in the event of an accident and the SW outlet piping degradation was limited to one heat exchanger, the health and safety of the public was not affected.

3.0 CAUSE OF THE EVENT It was determined that the hole in the SW piping was caused by a failure of the coal tar epoxy coating followed by corrosion of the elbow in the area of the coating failure. This coating was installed during plant construction.

The corrosion resulted in thinning of the pipe wall and eventually resulted in perforating the pipe.

4.0 IMMEDIATE CORRECTIVE ACTION{S)

Upon discovery of the hole in the SW piping, a DR was submitted and assignments made to evaluate the potential leakage paths from containment.

NRC FORM 366A (5-92)

NRC FORM 366A e U.S. NUCLEAR REGULATORY COMMISSION e APPROVED BY 0MB NO. 3150-0104

~ (5-92) EXPIRES 5/31/95

,I ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARJ LICENSEE EVENT REPORT (LEA) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATIO',

. AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR TEXT CONTINUATION REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

SEQUE"ITIAL REVISION YEAR NUMBER NUMBER Surry Power Station, Unit 1 05000-280 4 OF 5 94

- 003

- 00 TEXT //1 mor* space 1s required, use addioona/ copies of NRG Form 356A) (17) 5.0 ADDITIONAL CORRECTIVE ACTION(S}

The SW outlet piping on each heat exchanger was inspected utilizing a combination of visual and ultrasonic inspection techniques. Visual observations indicated similar coating failures in the other heat exchangers. No additional indications were identified on RSHX B. The A, C, and D RSHX SW elbows and SW outlet piping walls were found to be greater than code minimum wall thickness requirements. The RSHX B SW elbow will be replaced prior to unit startup.

The SW piping between the SW inlet and outlet isolation MOVs will be pressure tested in accordance with station procedures prior to start up.

6.0 ACTIONS TO PREVENT RECURRENCE In the past this piping was not routinely internally inspected.

A long term program to restore SW system piping is ongoing. The Unit 2 RSHX SW piping is included in the program. This program cleans, performs any required weld repairs, and installs a new high integrity epoxy coating system. For Unit 1, A and D inlet piping is complete and Band C inlet piping has been inspected, sandblasted and weld repaired. Inlet elbows B, C and D are complete and A has been inspected, sandblasted and weld repaired. Outlet elbow B has been inspected and weld repaired, A and C have had visual and ultrasonic inspections and D has had ultrasonic inspection only. Outlet piping A, B, and C have had visual and ultrasonic inspections and D has had ultrasonic inspection only.

Engineering has evaluated the as left condition of the SW piping as acceptable for the next operating cycle. The SW piping for the RSHXs will again be inspected during the next refueling outage. Repairs and re-coating will be completed as necessary.

7.0 SIMILAR EVENTS LER S1-91-019-00, Loss of Containment Integrity Due to a Crack in Component Cooling Water Piping NRG FORM 366A (5-92)

,

, NRC FORM 366A

~

U.S. NUCLEAR REGULATORY COMMISSION e APPROVED BY ()MB NO. 3150-0104 1' (5*92) EXPIRES 5/31/95 i

ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH fHIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND REj:ORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR TEXT CONTINUATION REGULATORY COMMISSION, WASHINGTON, DC 20555*0001, AND TO TIHE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (8) PAGE (3)

SEQUENTIAL REVISION YEAR NUMBER NUMBER Surry Power Station, Unit 1 05000 -280 5 OF 5 94 - 003 00 TEXT (II more space ,s requ,red, use additional copies of NRC Form 356<\) (17) 8.0 ADDITIONAL INFORMATION Portions of the Unit 2 RSHX SW piping were examined during the last refueling outage after pinhole leakage was discovered on the SW outlet elbow of the C RSHX. The C RSHX SW outlet elbow was repaired. The inspections identified no additional areas below minimum wall thickness requirements. The Unit 2 SW piping between the inlet and outlet isolation MOVs on each RSHX was satisfactorily pressure tested in accordance with station procedures.

The Unit 2 RSHX SW piping inside containment is part of the ongoing SW piping upgrade program. The inlet piping and elbows have been inspected and coated and the outlet elbows of one train have been examined.

Additional inspections will be completed during the next refueling outage.

Repairs and recoating will be completed as necessary.

NRC FORM 366A (5*92)