05000296/LER-1979-021-01, /01T-0:on 791208,following Refueling Outage & Unit 3 Return to Svc,Excessive Drywell Leakage Occurred.Caused by Loose Bolts Around Hatch Door.Bolts Were Retightened & Administrative Controls Initiated to Verify Seal Worthine

/01T-0:on 791208,following Refueling Outage & Unit 3 Return to Svc,Excessive Drywell Leakage Occurred.Caused by Loose Bolts Around Hatch Door.Bolts Were Retightened & Administrative Controls Initiated to Verify Seal Worthiness

ML18024B196
Person / Time
Site:	Browns Ferry
Issue date:	12/21/1979
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18024B195	List: 05000296/LER-1979-021-01, /01T-0:on 791208,following Refueling Outage & Unit 3 Return to Svc,Excessive Drywell Leakage Occurred.Caused by Loose Bolts Around Hatch Door.Bolts Were Retightened & Administrative Controls Initiated to Verify Seal Worthine
References
LER-79-021-01T, LER-79-21-1T, NUDOCS 7912280507
Download: ML18024B196 (4)

LER-1979-021, /01T-0:on 791208,following Refueling Outage & Unit 3 Return to Svc,Excessive Drywell Leakage Occurred.Caused by Loose Bolts Around Hatch Door.Bolts Were Retightened & Administrative Controls Initiated to Verify Seal Worthiness

Event date:
Report date:
2961979021R01 - NRC Website

text

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Form BF-17 BF 15e2 1/10/79 LER SUPPLEMENTAL INFORMATION BFRO-50-296

/ 7921 Technical Specification Involved 6.7.2.a.3 Reported Under Technical Specification 4.7,A.2.

Date of Occurrence

~12 8

7e Time of Occurrence 7~10

.m.

Unit 3

Identification and Descri tion of Occurrence:

Initial difficultywith maintenance of drywell to torus pressure differential.

Later it was discovered that excessive drywell leakage existed contrary to Technical Specification 4.7.A.2.g.

Leakage path was 'identified, repairs completed at 0830, and local leak rate test completed at 0930, 12/9/79, within 48-hour limit per Technical Specification 4.7.A.2.h(2).

Condit1ons Pr1or to Occurrence:

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

Unit 2 at 880 MWe, limited by reactor feed pump 2A 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.

Action specified 1n the Technical Specification Surveillance Requirements met due to inoperable e ui ent.

Describe.

Action specified in 4.7.A.2.h requires repairs to primary containment penetration leakage be initiated immediately and that unit be shut down 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.

A arent 'Cause of Occurrence:

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

Anal sis of Occurrence:

There was no danger to health or safety of the public, no activity release, and 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 11/21/79 and ll/26/79.

No leakage was observed on the east equipment hatch.

No other work was performed on southeast equipment hatch until the subject occurrence Correct1ve Action:

on 12/8/79.

Retightening of fasteners corrected leakage.

Developing administrative controls including detailed instructions and procedures which incorporate appropriate signoffs and a type of seal or lock that will verify that the hatch has not been disturbed since testing.

Failure Data:

None

• Retention:

Period - Lifetime; Responsibility - Administrative Supervisor

• Revision:

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