ML19330B523

Responds to IE Bulletin 80-14, Degradation of BWR Scram Discharge Vol Capability. Investigation to Determine How Frequently Scram Discharge Vol Vent & Drain Valves Should Be Tested Underway

ML19330B523
Person / Time
Site:	Hatch
Issue date:	07/25/1980
From:	Widner W GEORGIA POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19330B522	List: ML19330B521 ML19330B523
References
IEB-80-14, TAC-42218, TAC-42219, NUDOCS 8008040131
Download: ML19330B523 (3)

Text

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July 25, 1980

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U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement

REFERENCE:

Region II - Suite 3100 RII: JP0 101 Marietta Street, NW 50-321/50-366 Atlanta, Georgia 30302 I&E Bulletin 80-14 ATTENTION: Mr. James P. O'Reilly Gentlemen:

Following is Georgia Power Comoany's response to I&E Bulletin 80-14 which required certain action by us.

A review of plant records '.vas made for instances of degradation of any SDV level switch which was or may have been caused by a damaged or bent float assembly. Unit 1 SDV level switches IC11-N013A and ICll-N013B were found to be inoperable during performance of routine surveillance as per procedure HNP-1-3004 (high scram discharge volume level instrument FT&C). This was reported on June 13, 1979, by Reportable Occurrence Report v50-321/1979-038.

The float rods were found to be bent. The rods were straigntened and the switches wer? functionally tested per HNP-1-3004 These switches had pre-viously been udified cer DCR 74-24 (implemented by MR 74-1422) which re-placed Robert Shaw SDV level switches with Magnetrol level switches. The Robert Shaw level switch float could possibly have sunk during a scram, thus preventing the switch from returning to its normal position.

As a result of the occurrence mentioned above, the frequency of sur-veillance of the level switches was increased. For Unit i LER 50-321/1979-038, Rev. 1 required monthly surveillance for one quarter.

Even though the quarter period.is over, this surveillance per HNP-1-3004 is still being done monthly. Unit 2 Tech Spec 4.3.1-1(8) calls for monthly testing of the switches. These surveillance procedures ensure detection of any level switch degrada tion. Additionally, HNP-425, Deviation Report, requires that a deviation report be written upon discovery of any such such degradation. HNP-450, Reportable Occurrences, also requires notifying the NRC via an LER in such a Case.

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U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region II - Suite 3100 4

Page Two July 25,1950 A review of plant records revealed one occurrence of SDV vent / drain valve degradation. Valves 2Cll-F0108 and 2C11-F0ll failed to close during an RPS trip on May 11, 1980. The problem was found to be in another component, 2Cll-F009, which is a valve in :he air line which supplies 2Cll-F010B and 2Cll-F0ll.

This air valve was installed backwards so that the actuation signal failed to open valve 2Cll-F009. Consecuently, the air supply line to valves 2Cll-F010B and 2Cll-F0011 did not decressurize causing these valves not to close.

Deviation Report 2-80-315 and MR 2-83-2148 noted and corrected this condition by turning the valve around. This valve was then satisfactorily tested.

System vent and drain valves 1Cll-F010A, -F0103, -F011, and 2Cll-F010A,

-F0103, -F0li have all been manually tested in the past seven days by visually observing the ocening and closing of the valves and recording the closure times in reponse to NRC ILE Sulletin 30-17. Closing times are as folicws:

Unit 1 Test Date July 17, 1980 1

l Cll-F010A 42.4 sec i

Cll-F0103 45.75 sec

{

Cll-F0li 49.6 sec Unit 2 Test Date July 20, 1980

)

2Cll-F010A 25 sec i

2Cll-F010B 26 sec 2Cll-F0ll 25 sec There are no closure times required for these valves; therefore, there is no basis for required closing times.

A review of our plant records showed no instances in which water hammer or damage which may have been caused by water hammer occurred in SDV related piping. However, on May 21, 1980, the vent line leading from 2Cll-F010A was found to be bent and had torn loose one U-bolt mount.

The pipe was straightened and a new U-bolt mount attached. Reactive force (thrust) resulting from the pressurized SDV header blowing down to atmospheric pressure through the vent line may be the-cause. GPC is looking-at this further and may find it necessary to make vent pipe modifications.

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' CcCQI:J Power L U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region II - Suite 3100 Page Two July 25, 1980 An investigation is under way to determine how frequently the SDV vent and drain valves need to be tested to assure that they are open and operable.

A procedure will be subsecuently imolemented. An interim standing order has been issued to require that these valves be tested monthly, be normally open and operable, and that the NRC be notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if the SDV vent or drain valves on either unit are closed for more than one hour in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period while that unit is operating.

Approximately 51 manhours were expended in conducting the review and precaring the response required by this bulletin.

No manhours were associated with corrective actions.

f any additional information is recuired, please ;ontact this office.

Sincerely, a

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.g. ks W. A. Widner DLT/mb xc:

Director of the Office of Inspection and Enforcement Director of the Division of Operating Reactors, Office of Nuclear Reactor Regulation bc:

J. H. Miller, Jr.

C. E. Belflower W. E. Ehrensperger J. T. Beckham, Jr.

F. G. Mitchell, Jr.

O. Batum C. F. Whitmer V. C. Valekis R. J. Kelly R. A. Glasby J. H. Boykin R. F. Ro ers, III s

C. R. Thrasher R. W. Staffa M. Manry Route to SRB Members L. T. Gucwa

.