05000296/LER-1979-021, Supplemental LER 79-021/01T-1:on 791208,following Return to Svc After Refueling Outage,Primary Containment Pressure Would Not Stabilize.Caused by Leaking Due to Unevenly Tightened Bolts.New Controls & Hatch Lock to Be Used

Supplemental LER 79-021/01T-1:on 791208,following Return to Svc After Refueling Outage,Primary Containment Pressure Would Not Stabilize.Caused by Leaking Due to Unevenly Tightened Bolts.New Controls & Hatch Lock to Be Used

ML18024B323
Person / Time
Site:	Browns Ferry
Issue date:	02/05/1980
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18024B321	List: 05000296/LER-1979-021, Supplemental LER 79-021/01T-1:on 791208,following Return to Svc After Refueling Outage,Primary Containment Pressure Would Not Stabilize.Caused by Leaking Due to Unevenly Tightened Bolts.New Controls & Hatch Lock to Be Used
References
LER-79-021-01T, LER-79-21-1T, NUDOCS 8002080600
Download: ML18024B323 (4)

LER-1979-021, Supplemental LER 79-021/01T-1:on 791208,following Return to Svc After Refueling Outage,Primary Containment Pressure Would Not Stabilize.Caused by Leaking Due to Unevenly Tightened Bolts.New Controls & Hatch Lock to Be Used

Event date:
Report date:
2961979021R00 - NRC Website

text

UPDATE REPORT PREVTOU~PORT DATE 3.2-21;79 A

LlCENSEE EVENT REPORT v. o. gvut ncqsqgg.ge 4 wan 4 g,t4444444gvvgvgv 0

0 Qg 4

1 1

1 1 Q4~

Qg 25 26 LICENSE TYPE 30 S7 CAT 58 CONTROL BLOCK:

Q'PLEASE PRINT OR TYPE ALLREQUIRED INFORMATION) 1 6

A L

B R

F 02 0

0 0

0 0

0 0

9 LICENSEE CODE 14 15 LICENSE NUMBER 7

8

~02 soURcE ~LOB 0

5 0

0 0

2 9

6 7

1 2

0 8

7 9

OB 0

2 0

5 8

0 O~

60 61 DOCKET NUMBER EVENT DATE 74

. 75 REPORT DATE 80 FVENT DESCRIPTION AND PROBABLE CONSEQUENCES 010 With unit 3 at 200 MWe followi the

~03, primary containment pressure would not stabi 1ize per Technical Specification

3. 7. a. 2 ~

u7m

~'"""'0 5

safety of the public; no previous similar occurrences.

~OS

~07

~DS 80 7

8 7

8 9

SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE g

~@A Q77

~AQ72

~CQT3 2

Z Z

Z 2

Z Q74

~ZQPg

~Z Qls 9

10 11 12 13 18

'19 20 SEQUENTIAL OCCURRENCE REPORT REVISION LERIRO EVENT YEAR REPORT NO.

CODS TYPE NO.

QI7 ggpoaT

~79

~

~02 1

~~

~01

~ ~

1 21 22 23 24 26 27 28 29, 30 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP.

COMPONENT TAKEN ACTION ON PLANT METHOD HOURS Q22 SUBMITTED FORMhUB.

SUPPLIER MANUFACTURER QIB ~GQI9

~BQ20 PJQ2' 023 ~8 ~ Q2S 9

Q20 33 34 35 36 37 40 41 42 43

, 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q27 o

East drywall equipment hatch door was leakin due to two or ossibl three of twel~ve

unevenly tightened bolts.

Bolts were reti htened and hatch assed LLRT.

A tive controls are being developed to incorporate additional verifications and the use 3

of a 1ock to insure that the hatch is not moved without ro er a rove 1 4

80 METHOD OF DISCOVERY DISCOVERY DESCRIPTION Q32

~A Q31 Maintenance personnel observed 45 46 LOCATIONOf RELEASE Q NA 80 80 44 45 80 9'

ll 12 LOSS OF OR DAMAGE TO FACILITYQ43 TYPE 'ESCRIPTION

~ZQ42 NA 9 'o PUBLICITY ISSUED DESCRIPTION~

~NQ44 NA 7

8 80 80 NRC USE ONLY

~4 Te 80 Ta 0

2 0

68 69 8 9'0 PHONEME NAME OF PREPARER Boogoso IEg+

7 8

9 FACILITY STATUS

% POWER OTHER STATUS Q 0

Qgg ~02 0 Qgg NA 8

9 10 '

12 13 44 ACTIVITY CONTENT RELEASED OF RELEASE AMOUNTOF ACTIVITYQ

~IB

~Z Q33 2 Q34 NA 7

8 9'o

.11 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39

~oo o Q77~2Qgs NA 7

8 9

11 12 13 PERSONNEI. INJURIES NUMBER OESCRIPTIONQ41

~00 0 Qgo, 'NA

P

~ g I

~t je L

~:~, 7ennesse Valley Author ity Broivns Ferry Nuclear Plant Form BF-

'lv I.ER SUPPLEMENTAL lNFORNA'I1ON BFRO-5G-296 /

7921 Technical Specification Involve('.

4 ~ 7 A.2 ~ g Reported Under Technical SpecZication

6. 7. 2.a. 3 Date nf Occurrence 12/8/79 Time of Occurrence 7:10 p m i!nit Identification and Desc~ri tion'of Occurrence:

Initial difficultywith maintenance of drywell to torus pressure differential. Later it was discovered that excessive drywell leakage existed.

Leakage path identified and repaired at 0830, 12/4/79, within 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> limit per technical specification 4.7.A.2.h(2).

Conditions'Prior to Occurrence:

Unit 1 at 970 MWe, end-of-cycle coastdown.

Unit 2 at 880 MWe, limited by 2A reactor feed pump maintenance, unit 3 load at approximately 200 MWe following return to service of unit from refueling outage at 1615, 12/8/79. Unit in test program.

Actioti specified in the Technical Specification S>>rvcill itic~

1(equtrements mct due to inc~et ahl>> eqt~ipment..

l)csrt ibe.

Action specified in 4.7.A.2.g requires repairs to primary containment penetration leakage be ini.tiated immediately and that unit be shutdown within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> following detection if the leakage is not corrected.

parent Cause of Occurrence:

Leak around east equipment hatch seal due to 2 or possibly 3 loose fasteners immediately terminated leakage.

Analysis of Occurrence: There was no danger to health or safety of the public, no activity

release, no damage to plant equipment.

East equipment hatch was installed and initially failed a local leak rate test on ll/14/79.

The hatch was retorqued and passed the local leak rate test on ll/14/79. An integrated leak rate test was conducted between ll/21/79, and 11/26/79.

No leakage was observed on the east equipment hatch.

No other work was performed on southeast equipment hatch until the subject occurrence on 12/8/79.

Corrective Action

Retightening of fasteners corrected leakage.

Developing administrative controls including detailed instructions and procedures which incorporate appropriate signoffs and a. lock that will insure that the hatch is not moved without proper approval.

Fatlur>> !inta:

Tlone

• Ret<<n t;on:

+Bcvts Y>n:

Period

- L>fctinM; Rc:;pen ihility - Administrative Supervisor s

c

f