ML19344E900
| ML19344E900 | |
| Person / Time | |
|---|---|
| Site: | Hartsville, Phipps Bend  |
| Issue date: | 08/22/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8009120066 | |
| Download: ML19344E900 (1) | |
Text
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o UNITED STATES 8
NUCLEAR REGULATORY COMMISSION p
2 REGION 11 3
g g
101 MARIETTA sT., N.W., SUITE 3100 l
b ATLANTA. GEORGIA 30303 o
In Reply Refer To:
AM RII:JPO 50-518, 50-519 50-520,_.50-521 C 5'0-553, 50-55,4 J p,
u.b [ '_;
Tennessee Valley Authority
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ATTN:
H. G. Parris Manager of Power 500A Chestnut Street Tower II Chattanooga, TN 37401 Gentlemen:
The enclosed IE Supplement No. 3 to Bulletin No. 80-17 is forw rded to you for information. No written response is required. If your desire additional information regarding this matter, please contact this office.
Sincerely,
'QD James P. O'Reilly Director
Enclosures:
1.
IE Supplement No. 3 to Bulletin No. 80-17 2.
List of Recently Issued IE Bulletins cc w/ encl:
R. T. Hathcote, Project Manager J. F. Cox, Supervisor, Nuclear Licensing Section J. E. Wills, Project Engineer H. N. Culver, Chief, Nuclear Safety Review Staff W. P. r-lleghan, Project Manager 8009120 04 6
e SSINS: 6820 Accession No.:
8006190074 UNITED STATES 4
NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 August 22, 1980 IE. Supplement 3 to Bulletin No. 80-17: 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 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 wtrned.
In view of the possible single failure mechanism described r'ouve, the following actions are requested in addition to those specified in IE lulletit 80-17, Supplements 1 and 2:
1.
Far 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 effe t to:
a.
Require an immediate manual scram on low control rod drive air pressure 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.
i 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 o! IEB 80-17 Supplement No.1, may provide a basis for relaxation of the time for initiating a manual scram.
i IE Bulletin No. 80-17 August 22, 1980
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Supplement No. 3 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 bicek and scram switches after each scram event, before returning to power. This procedure should remain in effect until modifications in addition te Item B.1 of IEB 80-17 supplement No. I 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 Ju.ly 31, 1980. (Application for renewal pending before GAO.) Approval was given under a blanket clearance specifically for identified generic problems.
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IE Bulletin No. 80-17 August 22, 1980
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Supplement 3 RECENTLY ISSUED IE BULLETINS Bulletin No.
Subj ect Date Issued Issued To Supplement 3 Failure of Control Rods 8/22/80 All RWR power reactor to 80-17 to Insert During a Scram facilities holding OLs at a BWR 80-20 Failures of Westinghouse 7/31/80 To each nuclear Type W-2 Spring Return power facility in to Neutral Control Switches your region having an OL or a CP 80-19 Failures of Mercury-7/31/80 All nuclear power Wetted Matrix Relays in facilities having Reactor Protective Systems either an OL or a CP of Operating Nuclear Power Plants Designed by Combus-tion Engineering 80-18 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 Supplement 2 Failures Revealed by 7/22/80 All BWR power reactor to 80-17 Testing Subsequent to facilities holding OLs Failure of Control Rods to Insert During a Scram at a BWR Supplement 1 Failure of Control Rods 7/18/80 All BWR power reactor to 80-17 to Insert During a Scram facilities holding OLs at a BWR 80-17 Failure of Control Rods 7/3/80 All BWR power reactor to Insert During a Scram facilities holding OLs at a BWR 80-16 Potential Misapplication of 6/27/80 All Power Reactor Rosemount Inc., Models 1151 Facilities with an and 1152 Pressure Transmitters OL or a CP with Either "A" or "D" Output Codes 80-15 Possible Loss Of Hotline 6/18/80 All nuclear facilities With Loss Of Off-Site Power holding OLs 80-14 Degradation of Scram 6/12/80 All BWR's with an Discharge Volume Capability OL
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