ML19329G289
| ML19329G289 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/12/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8007140306 | |
| Download: ML19329G289 (1) | |
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g UNITED STATES NUCLEAR REGULATORY COMMISSION o
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REGION 11 o,
101 MARIETTA ST., N.W., SUITE 3100 s
s ATLANTA. GEORGIA 30303 In Reply Refer To:
JUN 121980 RII:JPO N 50-259 50-260 50-296 y v-Tennessee Valley Authority Attn:
H. G. Parris Manager of Power 500A Chestnut Street Tower II Chattanooga, Tennessee 37401 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.
I I
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.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely, James P. O'Reill Director Enclorures:
1.
List of Recently Issued IE Bulletins
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6 8007140 M b Q
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Tennessee Valley Authority JUN 121980 cc w/ encl:
J. R. Calhoun Director of Nuclear Power 1750 Chestnut Street Tower II Chattanooga, Tennessee 37401 H. L. Abercrombie Plant Superintendent Post Office Box 2000
'Decatur, Alabama 35602 R. E. Rogers, Project Engineer 400 Chestnut Street Tower II Chattanooga, Tennessee 37401 H. N. Culver 249-A HBB 400 Commerce Avenue Knoxville, Tennessee 37902 E;
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UNITED STATES 8005050056 NUCLEAR REGULATORY COMMISSION 0FFICE OF INSPECTION AND ENFORCEMENT l
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WASHINGTON, D.C.
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June 12, 1980 IE Bulletin No. 80-14
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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).
l 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 b
both switches. The licensee believes that the float rods were bent during or prior to initial installation and that metal particles from the modification 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 exc "
i for periodic draining. During this mode of operation the reactor scrammet L
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 F
alarm switch was bent such that the switches would not operate. The water f
hammer event discussed above was the reported cause of failure of these two
- switch assemblies.
(LER 79-74) f As a result of then events and related anticipated transients without scram (ATWS) studies, concern arises that the SDV function may be degraded by the undetected presence of fluid in the SDV. The second event is s4.gnificant in that it indicates the potential for a common cause failure (faulty solenoid)
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~ 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 r
i (NUREG 0460) have led the staff to propose, among other requirements, improve-ments in the SDV designs to reduce susceptibility to common cause failures.
By separate correspondence, the staff will provide example Technical Specifica-I tions related to the action items discussed below.
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o IE Bulletin No. 80-14 June 12, 1980 Page 2 of 2 A.
GE BWR's With an Operating License
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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.
Review 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 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 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
- j caused by water hammer has occurred in SDV related piping.
Identify the cause and corrective action for each instance.
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.
B.
Reporting Requirements 2.
$j The actica taken in response to the items in Part A shall be completed
- s and a written report on the results submitted to the NRC within 45 days 6
from the date of this Bulletin.
y This report should be submitted to the Director of the appropriate NRC Regional Office and a copy should be forwarded to the NRC Office cf Inspection and q}
Enforcement, Division of Reactor Operations Inspection, Washington, D.C.
3 20555.
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. Approved by GAO, B180225 (R0072); clearance expires 7-31-80. Approval was given under a blanket clearance specifically for identified generic problems.
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IE Bulletin No. 80-14 Enclosure June 12, 1980 RECENTLY ISSUED IE BULIETINS i
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, excepc 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
,a Deficiencies operating facilities and holders of power reactor construction permits 80-08 Examination of Containment 4/7/80 All power reactors with Liner Penetration ~delds 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 80-06
. Engineered Safety Feature 3/13/80 All power reactor
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(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 System (CVCS) Holdup OLs and to those with Tanks a CP s
-. + v; 179-01B..
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Environmental Qualification 2/29/80 All power reactor
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of Class IE Equipment facilities with an OL 80-04 Analysis of a PWR Main 2/8/80 All PWR reactor facilities Steam Line Break With
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holding OLs and to those Continued Feedwater nearing licensin8 Addition v
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