ML19329G284
| ML19329G284 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/12/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | John Miller GEORGIA POWER CO. |
| References | |
| NUDOCS 8007140294 | |
| Download: ML19329G284 (1) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION 4
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- 101 MARIETTA ST., N.W., SulTE 3100 ATLANTA, GEoRCIA 30303 In Reply Refer To:
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50-321 4
50-366 Georgia Power Company Attn:
J. H. Miller, Jr.
Executive Vice President 270 Peachtree Street, N.W.
Atlanta, Georgia 30303 Gentlemen:
Enclosed is IE Bulletin No. 80-14 which requires action by you with regard to your power reactor facility (ies) with an operating license.
In order to assist the NRC in evaluating the value/ impact of each Bulletin on licensees, it would be helpful if you would provide an estimate of the manpower expended in conduct of the review and preparation of the report (s) required by the Bulletin. Please estimate separately the manpower associated with correc-tive actions necessary following identification of problems through the Bulletin.
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l Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely, I
1 James P. O'Reill Director
Enclosures:
1.
List of Recently Issued IE Bulletins 4
8 0 0 7 i4 0 2.N Q
JUN 121980 Ge:rgis Pow r Coopsny
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M. Manry, Plant Manager Post Office Box 442 Baxley, Georgia 31513 C. E. Belflower Site QA Supervisor Post Office Box 442 Baxley, Georgia 31513 W. A. Widner, General Manager Nuclear Generation Georgia Power Company s
Post Office Box 4545 Atlanta, Georgia 30303 9
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UNITED STATES 8005050056 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 June 12, 1980 IE Bulletin No. 80-14 DEGRADATION OF BWR SCRAM DISCHARGE VOLUME CAPABILITY During our review of BWR operating experience, two events have raised concern on operations related to the control rod drive system scram discharge volume (SDV).
Description of Circumstances:
At Hatch Unit 1, on June 13, 1979, while performing surveillance to func-tionally test SDV high level switches, two switches (C11-N013A, B) were found to be inoperable. Redundant switches (C11-N013 C, D) were operable. The reactor was in the refuel mode and these switches had been modified prior to this occurrence.
Inspection of the inoperable level switches revealed that the float rod was bent and binding against the side of the float chamber on 7
both switches. The licensee believes that the float rods were bent during or prior to initial installation and that metal particles from the modification
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caused binding of the float.
(LER 79-038)
Brunswick Unit I reported that slow closure of the SDV drain valve during a reactor scram on October 19, 1979 apparently caused a water hammer event which damaged several pipe supports on the SDV drain line. Drain valve closure time was approximately five minutes due to a faulty solenoid controlling air supply to the valve. The damaged pipe supports were repaired but repair parts for the faulty solenoid were not available. To prevent possible damage from a scram, the unit started up with the SDV vent and drain valves closed except for periodic draining. During this mode of operation the reactor scrauned from high level in the SDV, without prior actuation of either the high level alarm or rod block switch. Subsequent inspection revealed that the float ball on the rod block switch was crushed and the float ball stem on the high level p
alarm switch was bent such that the switches would not operate. The water hammer event discussed above was the reported cause of failure of these two 3
switch assemblies.
(LER 79-74)
As a result of these events and related anticipated transients without scram (AIWS) studies, concern arises that the SDV function may be degraded by the undetected presence of fluid in the SDV. The second event is significant in j,
that it indicates the potential for a common cause failure (faulty solenoid) to result in operation of the SDV in a manner which could defeat both the
~ level switch function and the SDV draining function.
The ATWS generic studies (NUREG 0460) have led the staff to propose, among other requirements, improve-i ments in the SDV designs to reduce susceptibility to common cause failures.
By separate correspondence, the staff will provide example Technical Specifica-tions related to the action items discussed below.
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IE Bulletin No. 80-14 June 12, 1980 Page 2 of 2 A.
GE BWR's With an Operating License The following actions are to be taken by licensees of GE designed BWR facilities with an operating license:
1.
Review plant records for instances of degradation of any SDV level switch which was or may have been caused by a damaged or bent float assembly.
Identify the cause and corrective action for each instance.
2.
Revies plant records for instances of degradation of SDV vent and drain valve operability. Provide the closure times required and typically observed for these valves and the basis for the required closing times.
Identify the cause and corrective action for each instance of degradation.
3.
By procedures, require that the SDV vent and drain valves be normally operable, open and periodically tested.
If these valves are not operable or are closed for more than I hour in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period during operation, the reason shall be logged and the NRC notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Prompt Notification).
4.
Review instances in which water hammer or damage which may have been caused by water hammer has occurred in SDV related piping.
Identify the cause and corrective action for each instance.
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5.
Review surveillance procedures to ensure that degradation of any SDV level switch due to a damaged float or other cause would be detected and that inoperability from any cause would be reported to the NRC.
6.
If no functional test or inspection which would detect degradation of each SDV level switch has been performed during the past 3 months, make provisions to perform an inspection and functional test of all SDV level switch assemblies at the next reactor shutdown of greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> duration.
7 B.
Reporting Requirements b
The action taken in response to the items in Part A shall be completed 3
and a written report on the results submitted to the NRC within 45 days from the date of this Bulletin.
4 This report should be submitted to the Director of the appropriate NRC Regional Office and a copy should be forwarded to the NRC Office of Inspection and
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Enforcement, Division of Reactor Operations Inspection, Washington, D.C.
20555.
1
. Approved by GAO, B180225 (R0072); clearance expires 7-31-80. Approval was
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given under a blanket clearanet specifically for identified generic problems.
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IE Bulletin No.'80-14 June 12, 1980 Enclosure RECENTLY ISSUED IE BULLETINS Bulletin Subject Date Issued Issued To No.
80-13 Cracking In Core Spray 5/12/80 All BWR's with an Spargers OL 80-12 Decay Heat Removal System 5/9/80 Each PWR with an OL Operability 80-11 Masonry Wall Design 5/8/80 All power reactor facilities with an OL, except Trojan 80-10 Contamination of 5/6/80 All power reactor Nonradioactive System and facilities with an Resulting Potential for OL or CP Unmonitored, Uncontrolled Release to Environment I,
80-09 Hydramotor Actuator 4/17/80 All power reactor Deficiencies operating facilities and holders of power reactor construction permits 80-08 Examination of Containment 4/7/80 All power reactors with Liner Penetration Welds a CP and/or OL no later than April 7, 1980 80-07 BWR Jet Pump Assembly 4/4/80 All GE BWR-3 and Failure BWR-4 facilities with an OL f
80-06
. Engineered Safety Feature 3/13/80 All power reactor
' (ESF) Reset Controls facilities with an OL 80-05 Vacuum Condition Resulting 3/10/80 All PWR power reactor In Damage To Chemical Volume facilities holding Control Cystem (CVCS) Holdup OLs and to those with Tanks a CP 7[-01B ~
Environmental Qualification 2/29/80 All power reactor of Class IE Equipment facilities with an OL i
80-04 Analysis of a PWR Nain 2/8/80 All PWR reactor facilities Steam Line Break With holding OL3 and to those
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Continued Feedwater Addition nearing licensing r
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