ML20050C782
| ML20050C782 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Cooper, Arkansas Nuclear, River Bend, Waterford, South Texas, Comanche Peak, Fort Calhoun, 05000000, Fort Saint Vrain |
| Issue date: | 03/31/1982 |
| From: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | ARKANSAS POWER & LIGHT CO., GULF STATES UTILITIES CO., HOUSTON LIGHTING & POWER CO., KANSAS GAS & ELECTRIC CO., LOUISIANA POWER & LIGHT CO., NEBRASKA PUBLIC POWER DISTRICT, OMAHA PUBLIC POWER DISTRICT, PUBLIC SERVICE CO. OF COLORADO, TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| References | |
| NUDOCS 8204090351 | |
| Download: ML20050C782 (2) | |
Text
{{#Wiki_filter:_. N 4, UNITED STATES j p . [- ['k NUCLEAR REGULATORY COMMISSION REGION IV k, [ 611 RYAN PLAZA DRIVE. SUITE 1000 i y ARLINGTON. TEXAS 76011 ~ March 31, 1982 4 Gentlemen: The enclosed IE Information Notice provides notification of events that I may have safety significance. It is expected that recipients will review the information notice for possible applicability to their facilities. If you have any questions regarding this matter, please contact this office. Sincerely, t John T. Collins Regional Administrator
Enclosures:
I 1. IE Information Notice No. 82-10 2. List of Recently Issued IE Information Notices t 4 4 i 8204090351 820331 PDR ADOCK 05000267 [b G ppg b
m IE IflFORMATION NOTICE 82-10: FOLLOWING UP SYMPT 0MATIC REPAIRS TO ASSURE RESOLUTION OF THE PROBLEM Licensee Facility / Docket Number Arkansas Power and Light Conpany Arkansas Nuclear One, Unit 1 & 2 Little Rock, Arkansas 50-313; 50-368 Nebraska Public Power District Cooper Nuclear Statiori Columbus, Nebraska 50-298 Omaha Public Poser District Fort Calhoun Station Omaha, Nebraska 50-285 Public Service Company of Colorado Fort St. Vrain Generating Station Denver, Colorado 50-267 Gulf States Utilities River Bend Beaumont, Texas 50-458; 50-459 Houston Lighting & Power Company South Texas Project Houston, Texas 50-498; 50-499 Kansas Gas & Electric Company Wolf Creek Wichita, Kansas STN 50-482 Louisiana Power & Light Company Waterford-3 New Orleans, Louisiana 50-382 Texas Utilities Generating Company Comanche Peak Steam Electric Station Dallas, Texas 50-445; 50-446 ZX /W4 s 4/5/62 h Fan: a noq g,j,, pg.nsee hsf -{$r ZN-Wl0 RECEWED 9 p. O APR 8 19825 I "a"='%"l"[/ = /E3/ 'd
SSINS: 6835 Accession No.: --8202040126 _ eIN 82-10 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF It'SPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 March 31, 1982 IE INFORMATION NOTICE NO. 82-10: FOLLOWING UP SYMPTOMATIC REPAIRS TO ASSURE RESOLUTION OF THE PROBLEM Discussion: There have been a number of instances in which licensees have attempted to correct valve problems by treating the symptoms rather than the underlying cause. This failure to distinguish between the problem and its symptoms has resulted in recurrence of the problem and further damage to or destruction of the valve or operator. Symptomatic repairs provide for a return to operability without addressing the underlying problem, earning the label " quick and dirty fixes." The industry jargon recognizes not only that the immediate needs are met, but also that the underlying problem remains to be corrected. It is this second point which is emphasized: the underlying problem remains to be corrected. Specifically, valves that leak beyond Technical Specification limits have been restored to operability by allowing additional stem travel. The direct result of this symptomatic solution has been damage to or destruction of the valve or operator. One licensee has routinely backseated valves with Limitorque operators using the full motor torque in order to stop stem packing leakage, resulting in damage to the valve backseat. Bypassing the open limit switch allowed over-travel in the open direction resulting in binding of the stem in the stem nut. Because the unthreaded portion of the stem galled in the threads of the stem nut, the threads deformed and the nut cracked. The valves involved were 600 psi class, Anchor Darling Valve Company 10-inch integral backseat gate valves with pressure seal bonnets. Stem and body were type 316 stainless steel. I On a larger scale, in a survey of Licensee Event Reports (LER) for 1978 through 1980, 444 valve operator events were identified for 66 plants. Of these, 193 were identified 3; motor operator events. Corrective actions which involved i torque switches comprised the largest single corrective action group. The l principal means of corrective action identified was the adjustment of torque switch setting. This solution was applied to valves in similar service and,
IN 82-10 March 31, 1982 Page 2 of 2 repetitively, to the same valve at several plants. This indicates that the problem was not being corrected. The second major corrective action group was limit switch adjustments. This was a common solution to problems involving valve operation within a time limit. The cause for the problem is repeatedly given as instrument drift which is undoubtedly true as tcr as it goes; however, repetition of the events points to the need for a wider ranging solution which will prevent recurrences and improve system reliablity. During the survey period, there were 16 reported instances of motors replaced in motor operators in the high pressure coolant injection (HPCI), reactor core isolation cooling and residual heat removal systems of boiling water reactors. This was the third largest corrective action group. The damage that required replacement of some of the 16 motors resulted from thermal overload protection being bypassed and may be another indication that the underlying valve problem was not corrected. The common thread in the events as reported by LERs surveyed is the repetition of the problem or the solution, either of which can indicate that a symptomatic repair has been made. Symptomatic repairs become of concern to the NRC where they impact upon the reliability of the system and where they may adversely affect the health and safety of the public. When considering the solution to a valve problem, it must be recognized that a symptomatic repair may cause damage to the valve or operator which could impair the safety function of the system to which it is applied. Consideration snould be given to the kind of damage that can occur as a result of the repair and the consequences should a valve fail in a nonconservative direction. A mechanism should exist to identify and resolve the underlying problem when symptomatic repairs are applied. When the possibility exists for degradation of a safety system as a result of a temporary symptomatic repair to restore operability, prudence dictates a closer surveillance of the system so affected. This information notice is provided as notification of a potentially signi"icant matter. It is expected that recipients will review the information for applica-bility to their facilities. No specific action or response is required at this time. If you have any questions regarding this matter, please contact the Regional Administrator of the appropriate NRC Regional Office.
Enclosure IE Information Notice: 82-10 March 31, 1982 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Date Notice No. Subject Issued Issued To 80-32 Clarification of Certain 2/12/82 All fuel facility, materials, Rev. 1 Requirements for Exclusive-and Part 50 licensees Use Shipments of Radioactive Materials 82-01 Auxiliary Feedwater Pump 2/26/82 All power reactor facilities Rev. 1 Lockout Resulting from holding an OL or CP Westinghouse W-2 Switch Circuit Modification 82-03 Environmental Tests of 3/04/82 All power reactor facilities Electrical Terminal Blocks holding an OL or CP 82-04 Potential Deficiency of 3/10/82 All power reactor facilities Certain AGASTAT E-7000 holding an OL or CP 82-05 Increasing Frequency of 3/10/82 All power reactor facilities Drug-Related Incidents holding an OL or CP 82-06 Failure of Steam Generator 3/12/82 All power reactor facilities Primary Side Manway Closure holding an OL or CP Studs 82-07 Inadequate Security Screening 3/16/82 All power reactor facilities Programs holding an OL or CP 82-08 Check Valve Failures on 3/26/82 All power reactor facilities Diesel Generator Engine holding an OL or CP Cooling System 82-09 Cracking in Piping of Makeup 3/31/82 All power reactor facilities Coolant Lines at B&W Plants holding an OL or CP OL = Operating License CP = Construction Permit i -}}