05000280/LER-1991-019, :on 910828,through-wall Crack Discovered in Component Cooling Water Supply to Reactor Shroud Cooler B.On 910827,RCS Loop B Instrumentation Behaved Erratically.Caused by Leak in Piping.Piping Will Be Replaced

:on 910828,through-wall Crack Discovered in Component Cooling Water Supply to Reactor Shroud Cooler B.On 910827,RCS Loop B Instrumentation Behaved Erratically.Caused by Leak in Piping.Piping Will Be Replaced

ML18153C750
Person / Time
Site:	Surry
Issue date:	09/26/1991
From:	Kansler M VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
91-573, LER-91-019, LER-91-19, NUDOCS 9110010058
Download: ML18153C750 (5)

LER-1991-019, on 910828,through-wall Crack Discovered in Component Cooling Water Supply to Reactor Shroud Cooler B.On 910827,RCS Loop B Instrumentation Behaved Erratically.Caused by Leak in Piping.Piping Will Be Replaced

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
2801991019R00 - NRC Website

text

I

)

September 26, 1991 Virginia Electric and Power Company Surry Power Station P. 0. Box315 Surry, Virginia 23883 U. S. Nuclear Regulatory Commission Document Control Desk Serial No.:.91-573 Docket No.: 50-280 License No.: DPR-32 Washington, D. C. 20555 Gentlemen:

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

REPORT NUMBER 91-019-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by the Corporate Management Safety Review Committee.

Very truly yours, M. R. Kansler Station Manager Enclosure cc:

Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323 9110010059 910926 PDR ADOCK 05000280 S

PDR

)

NRC FORM 366 U.S. NUCLEAR REGU~ATORY COMMISSION APPROVED 0MB NO. 3150-0104 (6-891 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER)

INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) loocKET NUMBER 121 r

PAGE 131 Surry Power Station, Unit 1 o1s10101012,s,o 1 loF 0 14 TITLE (41 Loss of* Containment Integrity Due to a Crack in Component Cooling Water Piping EVENT DATE (51 LER NUMBER (61 REPORT DATE (71 OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR }?

SEQUENTIAL It?

REVISION MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(SI NUMBER NUMBER 0 Is Io I o I o I I

I Oj8 2 I s 9 1 91 1 -

01 11 9 -

olo 01 9 2 16 911 01S1010101 I

I OPERATING THIS REPORT IS SUBMITIED PURSUANT TO THE RcQUIREMENTS OF 10 CFR §: (Chock on* or moro of th* following) (11)

MODE 191 N

20.4021b) 20.406(cl 60.731oll2lliv) 73.711b) 1--

POWER I 1 20.406(ol(1 l(i) 60.3S(cll11 50.73111121M 73.71 (cl LEVEL 0 o-1--

1101 20.4061oll1 lliil 50.38lcll21 50.73(oll2llviil OTHER (Specify in Abstract (B) 1--

b*low,nri in Te~t. NRC Form i:,::.,.,.,.,.

]::::i::::::::J::::::::: Ii 1

20.406loll1 lliii)

X 50.731*112llil 60.73(o)l21(viiil(AI 366A)

/f i--

1--

20.405(11111 llvl 50.73(1)12llii) 60.73(0112) (viii) (Bl

,-:-.*.*. )/jf(::::

20.405lall1 IM 50.73(ol(2lliii) 50.73(oll2llx)

LICENSEE CONTACT FOR THIS LER (121 NAME TELEPHONE NUMBER AREA CODE M. R. Kansler, Station Manager 8 I O 14 31517 I -1311 1814 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 f::::::.::,:::.:::::::;:;:,::::::::::.::::::::::::,:,

1::::::::::::::::::::::::::::::::::::::::::::::::::

MANUFAC*

REPORTABLE MANUFAC-REPORTABLE l<*:*:*;.:-:-:,::*;,;,:.;,;,;,:,:-:*:::::::::::;:::

CAUSE

SYSTEM COMPONENT 1*.*.*.*.*.*.*... *.*.*.*.*.*.*.*.*.*.*.*.*;*.*.*.*>:

CAUSE

SYSTEM COMPONENT

,:-:-:-:-:::::;:::::::::::::::::::;:::?{')

TURER TO NPRDS TURER TO NPRDS r-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:

1:::::::::::::::::::::::::::::::::::::

It\\:

j::ii:J,

,:;:::::,:,:,:,:::,:;:,:-: (\\ (){

{}/}

I I

I I

???)'

()

I I

I I

I

,/:/

I I

I I

I

=:::=:::::...<<<

!ilii:ii!l{ll!i 11:::::::::::::1::::11:::i!i 1

\\/!:

11:i::rr:

I I

I I

I I

I I

I I I

I I I 1,:,:,::::::::::::::-*.*:*.*.*.*.

SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR EXPECTED

~

NO SUBMISSION n YES (If yos. comp/6'9 EXPECTED SUBMISSION DATE)

DATE 1151 I

I I

ABSTRACT (Limit to 1400 sp8ces, i.e.. tJpproximately fifteen single-space typewritten lines/ 116)

On August 28, 1991, with Unit 1 at 100% power and Unit 2 at 60% power, while investigating the erratic behavior of a portion of the primary plant instrumentation inside Unit 1 containment, a through-wall crack was discovered in the Component Cooling Water (CCW) supply to the "B" Reactor Shroud Cooler (l-VS-E-6B).

This portion of the ccw System utilizes an automatic return line isolation valve and a

membrane barrier for containment isolation.

When the piping wall was breached, containment integrity no longer existed.

A six-hour action statement to hot shutdown was entered at 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> on August 28, 1991.

The leak was isolated, and the action statement exited at 0611 hours0.00707 days <br />0.17 hours <br />0.00101 weeks <br />2.324855e-4 months <br />.

The health and safety of the public were not affected.

This event is reportable pursuant to 1 OCFR50. 73(a)(2)(i)(B ).

NRC Form 366 16-891 - ---- -------------16-891 FACILITY NAME 11 I e

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LEA)

TEXT CONTINUATION DOCKET NUMBER 121 APPROVED 0MB NO. 3150-0104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH IP-5301, U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT 13150-01041, OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

LEA NUMBER 161 PAGE 131 Surry Power Station, Unit 1 o Is I o I o I o 12 I 8 Io 91 1 -

o 11 I 9 -

ol o o I 2 OF o I 4 TEXT /If morw _,,. ia,wqund, u,. addltioMI NRC Fonn 35fiA'a) 1171 1. O DESCRIPTION OF THE EVENT 2.0 At 1950 hours0.0226 days <br />0.542 hours <br />0.00322 weeks <br />7.41975e-4 months <br /> on August 27, 1991, with Unit 1 at 100% power and Unit 2 at 60% power, a portion of the Unit 1 Reactor Coolant System (RCS) Loop "B" instrumentation (EIIS-IM) began to behave erratically.

The erratic instrumentation was declared inoperable and the affected channels were placed in "trip" at 2007 hours0.0232 days <br />0.558 hours <br />0.00332 weeks <br />7.636635e-4 months <br />.

At about the same time, operators noted an increase in containment sump in-leakage (0.61 gpm versus an initial value of about 0.1 gpm).

Upon sampling, the sump was found to contain chromates at the same concentration as that of the Component Cooling Water (CCW) System (EIIS-CC).

A containment entry was made, and a through-wall crack was discovered in the three-inch CCW supply line to the "B" Reactor Shroud Cooler (1-VS-E-6B) (EIIS-CD-HX).

Water from the leak was spraying on the "B" Loop Resistance Temperature Detector Manifold and had caused the earlier noted ~nstrumentation problems.

At 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> on August 28, 1991, a six-hour action. statement to hot shutdown was entered because of the violation of containment integrity.

This section of CCW piping utilizes an automatic return line isolation valve and a membrane barrier for containment isolation.

A membrane barrier consists of either pipe, tubing, or component wall.

When the pipe wall was breached, containment integrity no longer existed.

Operation above cold shutdown in this condition is prohibited by Technical Specification 3. 8.A.1.

The leak was isolated and the action statement was exited at 0611 hours0.00707 days <br />0.17 hours <br />0.00101 weeks <br />2.324855e-4 months <br /> on August 28, 1991.

This.event is reportable pursuant to 10CFR50.73(a)(2)(i)(B).

SIGNIFICANT SAFETY CONSEQUENCES *AND IMPLICATIONS The Surry Power Station Updated Final Safety Analysis Report describes the design bases for containment isolation during incident conditions as at least two barriers between the atmosphere outside containment and

• the atmosphere inside containment

• the reactor coolant and connecting systems.

The failure of one valve or barrier does not prevent isolation.

For CCW

piping, the two barrier arrangement is provided by a

membrane barrier inside containment and isolation valve arrangements in the piping entering and exiting containment.

The incoming isolation valve arrangement includes a

manual isolation valve in series with a check valve.

The outgoing piping is isolated by an automatic isolation valve.

During this event, bath the incoming and outgoing valve isolation arrangements remained

operable, thereby maintaining one containment integrity barrier intact.

Since containment was accessible, the leaking section of piping was isolated

,, (6-89)

FACILITY NAME (11 e

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LERI TEXT CONTINUATION DOCKET NUMBER (21 EXPIRES: 4/30/92 APPROVED 0MB NO. 3150-0104 MATEO BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

LER NUMBER (81 PAGE (31 Surry Power Station, Unit 1 o Is I o I o I o 12 1 a I o 91 1 _ o 11 1 9 _ o I o o 1 3 oF o 1 4 TEXT.(If mota -

ia 19qund, u*.,JdltionlJI NRC Fonn.BA '1) !171 3.0 by shutting manual supply and return valves 1-CC-30 and 1-CC-33 (EIIS-CC-ISV) inside containment, restoring the integrity of the remainder of the membrane barrier.

Since one containment integrity barrier remained operable and no event occurred which would have required isolation of the containment, the health and safety of the public were not affected.

CAUSE QF THE EVENT The cause of the leak in the three-inch CCW p1pmg was a through-wall crack which originated in the toe of a weld and propagated for about 25° around the circumference of the pipe.

Replacement of the affected piping is planned for the next cold shutdown of sufficient duration.

It is planned to conduct a failure analysis on the failed piping.

4. O IMM~DIATE CORRECTIVE ACTION<Sl The leak was isolated by closing the manually operated valves inside containment.

These valves were placed under

• administrative control.

• 5. O ADDITIONAL CORRECTIVE ACTION<Sl The affected section of piping will be replaced during the next cold shutdown of sufficient duration.

6. O ACTIONS TO PREVENT RECURRENCE The remaining Reactor Shroud Cooler CCW piping in both. units will be walked down and visually inspected for leaks.

Because of ALARA concerns, these walkdowns will be conducted during the next outages of sufficient duration.

Additional inspections will be scheduled as appropriate after the failure analysis has been completed and the results evaluated.

In addition, strengthened requirements barriers.

administrative control procedures will be reviewed and as necessary to assure that containment integrity are met in systems which depend upon membrane

7. o

SIMILAR EVENTS

LER 89-042-00 (Unit 1)

Leakage Through Fault in Letdown System Drain Line in Excess of Allowable Type "C" Leakage

(

- -----(6-89)

FACILITY NAME (11 e

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LERI TEXT CONTINUATION DOCKET NUMBER (21 Surry Power Station, Unit 1 0 IS IO Io Io,2 I s, 0 TEXT (If more -

ia r.qund, u* ttdditional NRC Fonn 3'i6A'*J (171 8.0

ADDITiONAL INFORMATION

None. A APPROVED 0MB NO. 3150-0104 EXPIRES: 4/30/92 ESTIMATED BURDEN PEA RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1'HE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

LER NUMBER (61 PAGE (3)

SEQUENTIAL ::::::::::* REVISION YEAR NUMBER

NUMBER 91 1 _

0 I ~ 9 _ 0 I O 01 4 OF O I 4