ML19344E886

Forwards Suppl 3 to IE Bulletin 80-17, Failure of Control Rods to Insert During Scram at Bwr. No Written Response Required

ML19344E886
Person / Time
Site:	LaSalle
Issue date:	08/22/1980
From:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Reed C COMMONWEALTH EDISON CO.
References
NUDOCS 8009120038
Download: ML19344E886 (1)

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UNITED STATES NUCLEAR REGULATORY COMMISSION o

E REGION 111

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799 ROOSEVELT ROAD g

GLEN ELLYN, ILLINOIS 60137

'AllG 9 2 $80 Docket No. 50-373, 50-374 Commonwealth Edison Company ATTN:

Mr. Cordell Reed Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:

The enclosed IE Supplement 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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[ttJames G. Keppler Director

Enclosure:

IE Supplement No. 3 to Bulletin 80-17 cc w/enci:

Mr. J. S. Abel, Director Director NRR/DPM of Nuclear Licensing Director NRR/ DOR Mr. L. J. Burke, Site AEOD Construction Superintendent PDR Mr. T. E. Quake, Quality Local PDR Assurance Supervisor NSIC Mr. R. H. Holyoak, Station TIC Superintendent Mr. Dean Hansell, Office Resident Inspector, RIII of Assistant Attorney Central Files General

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$5 INS:

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AccQssion No.:

8006190074 UNITED STATES

.g NUCLEAR F.EGULATORY 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.issutd on August 19, 1980.

It involves gradual or partial loss os 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:

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 ai.

amediate 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 oi. :er 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.

IE Bulletin No. 80-17 August 22, 1980 Supplement No. 3 Page 2 of 2 2.

1 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 raturning to power.

This procedure should remain in effect until modifications in addition to Item B.1 of IEB 80-17 supplement No. I are complet.ed 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.x ve, 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 Ei.forcement, 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.

s IE Bulletin Na. 80-17 August 22, 1980 Supplement 3 RECENTLY ISSUED IE BULLETINS Bulletin No.

Subject Date Issued Issued To 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 LP 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 Fc11owing and to those PWRs Secondary Si k 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 i

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