05000311/LER-1982-055, Forwards Updated LER 82-055/03X-1.Detailed Event Analysis Encl

Forwards Updated LER 82-055/03X-1.Detailed Event Analysis Encl

ML20064C264
Person / Time
Site:	Salem
Issue date:	12/08/1982
From:	Midura H Public Service Enterprise Group
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20064C266	List: 05000311/LER-1982-055, Forwards Updated LER 82-055/03X-1.Detailed Event Analysis Encl
References
NUDOCS 8301040361
Download: ML20064C264 (4)

LER-2082-055, Forwards Updated LER 82-055/03X-1.Detailed Event Analysis Encl

Event date:
Report date:
3112082055R00 - NRC Website

text

.. - O PSEG Public Service Electric and Gas Company P.O. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station December 8,'1982 Mr. R. C. Haynes Regional Administrator USNRC Region 1

) 631 Park Avenue i King of Prussia, Pennsylvania 19406 t

Dear Mr. Haynes:

LICENSE NO. DP R- 7 5

, DOCKET NO. 50-311 REPORTABLE OCCURRENCE 82-055/03X-1 SUPPLEMENTAL REPORT Pursuant to the requirements of Salem Generating Station Unit No. 2 Technical Specifications, Section 6.9.1.9.b, we are submitting supplemental Licensee Event Report for Reportable Occurrence 82-055/03X-1.

Sincerely yours, l

h..flkbzny H.J. Midura General Manager -

Salem Operations RII:ks v

['

( CC: Distribution

/

8301040361 821208 ,

l PDR ADOCK 05000311 / p' S PDR I 1.

The Energy People m :w c:.v m L

l Report Number: 82-055/03X-1 Report Date: 12-08-82 Occurrence Date: 06-21-82 Facility: Salem Generating Station, Unit 2 Public Service Electric & Gas Company Hancocks Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

100' Elevation Containment Air Lock - Inoperable.

This report was initiated by Incident Report 82-158.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 - Rx Power 100 % - Unit Load 1120 MWo.

DESCRIPTION OF OCCURRENCE:

At 1540 hours0.0178 days <br />0.428 hours <br />0.00255 weeks <br />5.8597e-4 months <br />, June 21,1982, personnel attempting to enter the 100' Elevation Containment Air Lock were unable to open the outer door. Investigation of the problem revealed that the inner door latch mechanism had failed, and the door could not be latched in the closed position. This disabled the outer door through the interlock which prevents simultaneous operation of both doors. The inner door had apparently swung open rapidly, breaking the swing chain and bending the mechanical stop. The 100' Elevation Containment Air Lock was declared inoperable, and Technical Specification Action Statement 3.6.1.3.a was entered retroactive to the time of discovery. The outer door was operable and was maintained closed to provide containment integrity. The handwheels outside the air lock were locked together to prevent operation of the door.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

The inner door latch bar assembly apparently did not fully engage the rollers the previous time the door was closed, due to a sheared pin on the locking plate assembly. The latch was sufficiently engaged for the door to pass Surveillance Procedure 4.6.1.3A, however. Upon the completion of the test, the air supply valve to the seal interspace was inadvertently left open. The latch bar engagement then shifted resulting in leakage past the inner seal and pressurization of the air lock itself. Pressure apparently increased until sudden disengagement of the latch caused the door to swing open rapidly.

LER 82-055/03X-1 o ,

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE: (continued)

The sheared locking plate pin likely resulted from improper operation of the latch mechanism. Personnel, while closing the door, increase the speed of the handwheel during the free rotation part of operation, to gain momentum for the portion which is more difficult due to latch engagement. This results in excessive shear forces on the locking plate pin, each time the latch bar contacts the roller assembly.

A_N_ALYSIS OF OCCURRENCE:

The containment air lock doors allow for personnel access to the Containment Building while providing a redundant barrier as part of overall containment integrity. This barrier prevents the release of radioactive contamination to the environment in the event of a design basis accident. Since the outer door was maintained closed, the containment integrity was maintained, and no risk to the health or safety of the public was involved. No damage beyond that to the air lock door itself resulted from the incident; no personnel injury occurred. The event constituted

! inadequacies in the implementation of procedural controls which threaten to cause a reduction of the degree of redundancy provided in an engineered safety feature system, and is reportable in accordance with Technical Specification 6.9.1.9.c.

Action Statement 3.6.1.3 requires:

With one containment air lock door inoperable, lock the operable air lock door closed, and operation may then continue until performance of the next required overall air lock leakage test, provided that the operable air lock door is verified to be locked closed at least once per 31 days; otherwise, be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shut-down within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

CORRECTIVE ACTION:

i Air to the seal interspace was isolated, and as noted, the outer door was maintained locked closed, in compliance with the action statement. The locking plate pin was replaced, and the swing chain and mechanical stop were repaired. Surveillance Procedure SP (0) 4.6.1.3A was satisfactorily completed, and the 100' Elevation Containment Air Lock was declared operable. At 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br />, ,

June 24, 1982, Action Statement 3.6.1.3.a was terminated.

1 LER 82-055/03X-1 CbRRECTIVE ACTION: (continued)

Proper operation of the air lock doors is presently addressed in the radiation worker training program. Special emphasis has been placed on the importance of engaging the latch slowly to prevent damage to the latch mechanism. The surveillance procedure presently requires that the air to the seal intersp.tce be isolated following testing of the outer door. Personnel responsible for performance of the surveillance procedure were counseled concerning the incident and the possible results of leaving the air valve open. Finally, a DCR has been submitted to relocate the air valve to a more visible location in consideration of the human factors involved.

FAILURE DATA:

Since January 1, 1982, there have been a total of 7 occasions on which containment air locks have failed. Of these, 6 involved the 100' Elevation Air Lock, and 5 were due to problems with the inner door latch. The concentration of problems is likely due to the more frequent use of the lower elevation air lock for containment access.

Chicago Bridge and Iron Co.

Personnel Air Lock Locking Plate Pin Prepared By R. Heller . ./ 4 Mc . s-6/ General Ma6ager -

Salem Operations SORC Meeting No.82-109

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