ML19344E877
| ML19344E877 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 08/22/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Draper E NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 8009120026 | |
| Download: ML19344E877 (1) | |
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UNITED STATES CENTRAL FILES j.,% E,[f i NUCLEAR REGULATORY COMMISSION PDR:HQ 3
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August 22, 1980 D:ckst No. 50-298 Nebraska Public Power District ATTN:
J. M. Pilant, Director Licensing & Quality Assurance Post Office Box 499 Columbus, Nebraska 68601 Gentlemen:
Enclosed is II Supplement No. 3 to Bulletin No. 80-17 which requires action by you with regard to your power reactor facility 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.
Should you have any questiot s regarding this Bulletin or the actions required by you, please contact this )ffice.
Sincerely, f,
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-Karl V. Se'yfrit
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Director Inclosuras:
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II Supplement No. 3 to 3ulletin No. 80-17 2.
Recently issued II 3ulletins cc:
L. C. Lessor, Superncendent Cooper Nuclear Station
?ost Office Sox 98 3rownv111e, Nebraska 68321
.8009120 026
SSINS:
6820 Accession No.:
8006190074 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 80-17, Supplement No. 3 Date: August 22, 1980 Page 1 of 2 FAILURE OF CONTROL RODS TO INSERT DURING A SCRAM AT A BWR NRC staff evaluation of a potential single failure mechanism of the control rod drive control air system has identified the need for licensee actions in addition to those requested by IEB 80-17 and Supplements 1 and 2.
The potential single failure was discussed in IE Information Notice 80-30, which was issued on August 19, 1980.
It involves gradual or-partial loss of control air system pressure, which could cause pcrtial opening of scram outlet valves without rod motion. The resultant act 'mulated seal leakage could conceivably fill the scram discharge volume in a few minutes.
Since not all operating BWR's have instrumentation presently installed to continuously indicate water level in the scram discharge volume headers and to provide a control room
~
alarm or scram function, the possibility exists for the scram discharge volume to fill to a level which could prevent reactor scram before automatic protective action or before the operators coulu be warned.
In view of the possible single failure mechanism described above, the following actions are requested in addition to those specified in IE Bulletin 80-17, Supplements 1 and 2:
1.
For those plants in which the scram discharge volume headers are connected to the instrument volume by a 2-inch pipe, within five days of the date of this Bulletin, proviae or verify that procedures are in effect to:
a.
Require an immediate manual scram on low control rod drive air pressure with a minimum 10 psi margin above the opening pressurn of the scram outlet valves.
b.
Require an immediate manual scram in the event of:
(1) Multiple rod drift-in alarms, or (2) A marked chat.ge in the number of control rods with high temperature alarms.
Installation of water level instrumentation in the scram discharge volume with level alarm and continuous level indication in the control room, in response to Item B.1 of IEB 80-17 Supplement No.
1, may provide a basis for relaxation of the time for initiating a manual scram.
F IE Bulletin No. 80-17, Supplement No. 3 Date:
August 22, 1980
- Page 2 of 2 2.
In addition, every BWR licensee is requested within five days of the date of this bulletin to provide and implement procedures which require a functional test using water for the instrument volume level alarm, rod block and scram switches after each scram event, before returning to power.
This procedure should remain in effect until modifications in addition to Item B.1 of IEB 80-17 S",plement No. 1 are completed to substantially increase reliability of sater level indication in the scram discharge volume (s).
Licensees of all operating BWRs shall submit a report summarizing action taken in response to the above items within 10 days of the date of this Bulletin Supplement. Accordingly, you are requested to provide within 10 days as specified above, written statements of the above information signed under oath or affirmation.
Reports shall be submitted to the Director of the appropriate NRC Regional Office and a copy forwarded to the Director, Division of Reactor Operations Inspection, NRC.
Office of Inspection and Enforcement, Washington, D.C.
20555 Approved by GAO, B180225 (R0072); clearance expires July 31, 1980. (Application for renewal pending before GA0.) Approval was given under a blanket clearance specifically for identified generic problems.
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- 4 IE Bulletin No. 80-17, Supplement No. 3 August 22, 1980 RECENTLY ISSUED IE BULLETINS Bulletin Subject Date Issued Issued To No.
Sup. 1 Failure of Control Rods 7/18/80 All BWR power reactor to 80-17 to Insert During a Scram facilities holding Operating at a BWR Licenses (OLs) or Con-struction Permits (cps)
Sup. 2 Failures Revealed by 7/22/80 All BWR power reactor to 80-17 Testing Subsequent to facilities holding Failure of Control Rods Operating Licenses (OLs) to Insert During a Scram or Construction Permits at a BWR (cps) 80-13 Maintenance of Adequate 7/24/80 All PWR power reactor Minimum Flow Thru Centrifugal facilities holding OLs Charging Pumps Following and to those PWRs Secondary Side High Energy nearing licensing Line Rupture 80-19 Failures of Mercury-Wetted 7/31/80 All nuclear power Matrix Relays in Reactor facilities having Protective Systems of either an Operating Operating Nuclear Power License (OL) or a Plants Designed by Combus-Construction Permit (CP) tion Engineering 80-20 Failures of Westinghouse 7/31/80 To each nuclear Iype W-2 Spring Return power facility in to Neutral Control your region having Switches an Operating License (OL) or a Construction Permit (CP)
Enclosure