ML19269D167

LER 79-016/03L-0:on 790124,emergency Lock Failed Leak Rate Test While Unit in Mode 5.Caused by Loosening of Shaft Seal (Teflon Packing) Due to Routine Use of Escape Lock.Packing Will Be Replaced During Next Convenient Outage

ML19269D167
Person / Time
Site:	Davis Besse
Issue date:	02/20/1979
From:	Brown R TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19269D165	List: ML19269D164 ML19269D167
References
LER-79-016-03L, LER-79-16-3L, NP-33-79-19, NUDOCS 7902270412
Download: ML19269D167 (2)

Text

U. S. NUCLEAR REGULATORY COMMI., !

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.. m LICENSEE EVENT REPORT (PLE ASE PRINT OR TYPE ALL REQUIRED INFORL*.ATION)

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DATE 74 13 REPORT DATE 80 7 8 60 61 DOCKET NUYBER EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h o 2 lOn 1/24/79 at 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br />, the emergency lock f ailed its leak rate test. I l o 13 l l Tech Spe. 3.6.1.3 c equircs both containment (CTMT) air locks be operable in Modes 1, 2{

g o ;4 ; 3, and 4. The unit was in Mode 5. The leak uas repaired. At 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on 1/24/79, l

[TlT] l the cmergency lock was tested satisfactorily. There was no danger to the health and l o c l safety of the public or un't personnel. There was no leakage on the interior door of l l o l 7 ! I the emergency lock which would have prevented any leakane had CTMT isolation heen J

o a [ r equ ir ed. (NP-33-79-19) 60 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COVPoNENT CODE SUSCODE SUBOODE lol9l8 7

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33 25 l36Zl@ 3/ 40 41 42 43 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS

[i j o l lThe apparent cause of this occurrence is the loosening of a shaft seal (teflon pack- l i i ing) due to routine use of the escape lock (exit / entry to CTMT). The shaft seals .I

! were tightened to prevent excessive leakage. The packing will be replaced during j

],l3l lthe ncxt convenient outage under Maintenance Work Order 79-1203. l l

I t 141 l 80 7 8 9 ST S *.POV.E R OTHER STATUS DISCOV HY DidCOVERY DESCRIPTION 32

[TITl W @ @ 0 0 @ [ NA l l B l@l Surveillance Test, ST 5061.02 l ACTIVITY CONTENT RELEASED OF RE LE ASE AVOUNT OF ACTIVITY loc ATION OF RELE ASE 1 6 W@l d@lNA l l NA I 44 45 80 7 8 9 to 11 PERSONNEL EXPOSURES NUVBER TYPE DEECRIPTION i 7 1010! oj@l Zl@l NA l PERSONNEL INJUH ES NUYttE R DE SCRIP TION l

1 H 0l 0l 0 NA 80 7 8 9 11 12 LOSS OF CR DAVAGE To F ACILITY TYPE DESchrPTICN 1 9 8 9

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7 8 9 DVR 79-022 NA E F F P R PHONE

TOLEDO EDISON COMPANY DAVIS-BESSE h"dCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFOR'4ATION FOR LER NP-33-79-19 DATE OF EVENT: January 24, 1979 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Overall air lock leakage rate for emergency lock exceeded Technical Specification limit Conditions Prior to Occurrence: The unit was in Mode 5, with Power (MWT) = 0, and Load (Gross MWE) = 0.

Description of Occurrence: At 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> on January 24, 1979, during the aerfor-mance of Surveillance Test ST 5061.02, " Volumetric Leakage Test" for the er.2rgency lock, the leakage rate exceeded the allowable leakage rate of Technical Spa :ification 3.6.1.3. Technical Specification 3.6.1.3 requires both containment airlock. be operable in Modes 1, 2, 3, and 4. Leakage was detected at the shaft seal on t_a lower handwheel of the exterior door. This is being reported as a component f ailure.

Designation of Apparent Cause of Occurrence: The apparent cause of this occurrence is the shaf t seal (teflon packing) loosened due to use of the emergency lock (exit /

entry to containment).

Analysis of Occurrence: There was no danger to the health and safety of the public or to unit personnel. There was no leakage cetected on the interior door of the emergency lock which would have prevented any leakage from containment leaking to an outside area if containment isolation had been needed.

Corrective Action: Ths shaft seal of the lower exterior door handwheel on the emergency lock was tightened per Maintenance Work Order 79-1381, and the Volumetric Leakage Test, ST 5061.02, was successfully completed at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on January 24, 1979.

Maintenance will secure the packing and/or chauge out the packing per Maintenance Work Order 79-1403 at the next convenient outage.

Failure Data: There has been one previously reportable occ trrence of excessive cmergency lock leakage, see Licensee Event Report NP-33-78-13.

LER #79-016