ML19344E876
| ML19344E876 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/22/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Draper E GULF STATES UTILITIES CO. |
| References | |
| NUDOCS 8009120025 | |
| Download: ML19344E876 (1) | |
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Yi NUCLEAR REGULATORY COMMISSION 3,% e q(/
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REGION IV
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G11 RYAN PLAZA oRIVE, SUITE 1000
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ARLINGTON, TEXAS 76012 August 22, 1980 Yn Reply Refer To:
RIV Docket Nos. 50-458/IE Bulletin No. 80-17, Supplement No. 3 50-459/IE Bulletin No. 80-17, Suoplement No. 3 Gulf States Utilities Attn:
Dr. E. Linn Draper, Jr.
Vice President - Technology Post Office Box 2951 Beaumont, Texas 77704 Gentlemen:
The enclosed IE Supp M ment No. 3 to Bulletin 80-17 is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
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- Karl V. S frit,- f/
Director L
Enclosures:
1.
IE Supplement No. 3 to Bulletin 80-17 2.
Recently issued IE Bulletins
.8009120 02 5
SSINS:
6820 Accession No.:
8006190074 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEFINT 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 IEE 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 partial opening of scram outlet valves without rod motion.
The resultant accumulated 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 could 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, provide or verify that procedures are in effect to:
Require an immediate manual scram on low control rod drive air pressure a.
with a minimum 10 psi margin above the opening pressure 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 change 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.
l
t 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 Supplement No. 1 are completed to substantially increase reliability of water 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 GAO.) Approval was given under a blanket clearance specifically for identified generic problems.
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3 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 Centrol Rods 7/18/80 All Bh1 power reactor to 80-17 to Insert During a Scram facilities holding Operating at a Bk1 Licenses (OLs) or Con-struction Permits (cps)
Sup. 2 Failures Revealed by 7/22/80 All Bh1 power reactor to 80-17 Testing Subsequent to facilities holding Failure of Control Rods Operating Licenses (OLs) te Insert During a Scram or. Construction Permits at a Bk1 (cps) 80-18 Maintenance of Adequate 7/24/80 All PhR power reactor Minimum Flow Thru Centrifugal facilities holding OLs Charging Pumps Following and to those P%Rs 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 s
80-20 Failures of Westinghouse 7/31/80 To each nuclear Type W-2 Spring Return power facility in to Neutral Control your region having Switches an Operating License (0L) or a Construction Permit (CP) i Enclosure i
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