ML19330B862
| ML19330B862 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 07/18/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dewitt R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8008070091 | |
| Download: ML19330B862 (1) | |
Text
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- Coq'o, UNITED STATES E
NUCLEAR REGULATORY COMMISSION o
E REGION lli e
P 799 ROOSEVELT ROAD e
GLEN ELLYN. ILLINOIS 60137
'JUL' 181980 Docket No. 50-155 tonsumers Power Company ATTN:
Mr. R. B. DeWitt Vice President Nuclear Operations 212 West Michigan Avenue Jackson, MI 49201 Gentlemen:
Enclosed is IE Supplement No. I 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 required by the Bulletin. Please estimate separately the manpower associated with corrective actions necessary following identification of problems through the Bulletin.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely,
%gh )('-
'~
,// James G. Kepp r
Director
Enclosures:
1.
IE Supplement No. I to Bulletin No. 80-17 2.
List of Recently Issued IE Bulletins cc w/ encl:
Mr. D. P. Hoffman, Nuclear PDR Licensing Administrator Local ppt Mr. C. J. Hartman, NSIC Plant Superintendent TIC Central Files Rona'.d Callen, Michigan Public Director, NRR/DPM Siervice Commission Director, NRR/ DOR 8008070oq\\
t SSINS No.: 6820 Accession No.
UNITED STATES 8006190027 s AS.
NUCLEAR REGULATORY C0m4ISSION
'f~
l OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 July 18,1980 IE Bulletin No. 80-17 Supplement No. 1 FAILURE OF 76 0F 185 CONTROL RODS TO FULLY INSERT DURING A SCRAM AT A BWR Description of Circumstances:
Please refer to IE Bulletin 80-17, issued July 3,1980, for complete details of the initiating e M at.
Although we are essentially confident that the event was caused by water in the Scram Discharge Volume (SDV) system, we do not yet have a complete explanation as to why the water was present. The best estimate is that some type of blockage existed in the vent and/or drainage system for the SDV, precluding adequate drainage. To ensure that the SDV is empty, Browns Ferry (BF-3) has installed instrumentation to continuously monitor the water level in the scram discharge volume.
Such instrumentation is being considered by other plants.
Since issuance of IE Bulletin 80-17, additional information has been identified.
Specifically:
a)
At Browns Ferry a discrepancy was found between the "as-built" scram discharge system and the "as-designed" system. An unused one-inch (1") instrument line was found uncapped on the four-inch (4") drain header on the west side (the side whose rods scrammed) scram discharge volume vent system of Unit No. 3.
It is believed that this line improved the venting, and therefore the drain time for that system.
i b)
It has been determined that the vent systems on some scram discharge volumes interconnect with vent headers that are also common with and are connected to other systems.
The interconnected " vent" systems may contain water drained or being drained from those other systems.
i This water could potentially affect performance of the SDV.
- Also, both the vent and drain systems for the scram discharge system may contain long lengths of relatively small bore piping.
Designs specify a very gradual slope, such that small errors in the "as-installed" piping could result in degraded performance (for example, due to loop seals).
c)
Concerns have been expressed within the NRC Staff regarding potential delays that may occur before start of injection of boron into the BWR system from the Standby Liquid Control System (SLCS) when this manual operator action is required. The potential delays could be caused by f'
O IE Bulletin No. 80-17 July 18,1980 Supplement No. 1 Page 2 of 3 unavailability of the.SLCS key which is required to initiate this system, and/or administrative delays which require supervisory approval before the SLCS can be manually initiated by the control room licensed operator.
In view of the above items, the following actions in addition to those specified in IE Bulletin 80-17 are to be taken by BWR licensees.
A.
Actions to be Taken by BWR Licensees Upon Receipt and to be Reported Within 20 Days of the Date of This Letter:
1)
Provide to the NRC Regional Office an analysis of the adequacy of the "as-built' SOV system and associated vent and drain systems, including any identified design deficiencies.
Include copies of verified "as-built" isometric drawings of the SLV and detailed descriptions of the remainder of the system,- verified to be correct, as part of this analysis.
2)
Revise and implement Operating Procedures as necessary to provide clear guidance to the licensed operator in the control room regarding when he should initiate the SLCS without obtaining prior supervisory approval.
Provide a description of the implemented procedural requirements.
3)
Assure that procedures exist and are implemented for specifying remedial action to be taken if water is found in the SDV system at times when it should be free of water.
Provide a description of the implemented procedural requirements.
4)
Revise and implement administrative procedures as necessary to ensure that the SLCS key shall be readily available to the licensed operator in the control room.
Provide a description of the implemented pro-cedural requirements.
5)
Continue daily monitoring of water levels in all scram discharge selumes until continuous monitoring system (s) (discussed in 8.1 below) is (are) installed and operational (this requirement supersedes the requirements of Item 5 of IE Bulletin 80-17 which required daily surveillance for only 6 days).
B.
Actions to be Taken by BWR Licensees and Completed by September 1, 1980:
1)
Install a system to continuoi: sly monitor water levels in all scram discharge volumes.
Continuous recording and alarm features must be included in the design.
Consideration should be given to use of diverse level sensors in this (these) system (s). The. design installed should represent the design with the highest level of reliability compatible with completion of installation by September 1, 1980.
Provide a written description of the system design to the NRC Regional Office.
IE Bulletin No. 80-17 July 18,1980 Supplement No. 1 Page 3 of 3 If installation by September 1,1980 is not possible, by August 15, 1980, submit to the NRC Regional Office:
1)
Documentation in detail why the installation cannot be completed by 9/1/80.
2)
A commitment to a firm schedule for installation.
3)
A commitment to equipment changes and/or surveillance requirements in addition to those now in effect that will provide adequate assurance of SDV operability in the interim until installation is completed.
2)
Perform a study of potential designs for improving the venting system for the scram discharge volumes and submit a description to NRC by September 1, 1980.
Improvements such as providing a redundant, independent vent for each significant volume in the system or locally installing vacuum breakers close to each such volume should be con-sidered (some plants already include a design which vents locally to atmosphere).
Include an estimate of the time that would be required to accomplish these modifications in your report to be subicitted to the NRC Regional Office. We have been told that meetings have already been scheduled by GE to discuss their proposals in this area with licensees.
Additional requirements are under consideration and will be the subject of further communication from NRC.
Licensees of all operating BWRs shall submit the information requested within the specified allowable times. This information is requested under the provis-ions of 10 CFR 50.54 (f).
Accordingly, you are requested to provide within the time periods 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 Operatinns Inspection, NRC. Office of Inspection and Enforcement, Washington DC 20555.
Approved by GAO, B180225 (R0071); clearance expires 7-31-80.
Approval was given under a blanket clearance specifically for identified generic problems.
r IE Bulletin No. 90-17 Enclosure Supplement No. 1 July 18, 1980 RECENTLY ISSUED IE BULLETINS 1 Bulletin Subject Date Issued Issued To
-No.
80-17 Failure Of Control Rods To 7/3/80 All BWR power reactor Insert During A Scram At A facilities holding BWR OLs 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 80-13 Cracking In Core Spray 5/12/80 All BWR's with an Spargers OL 80-12 Decay Heat Removal System 5/9/80 Each PWR with an OL Operability 80-11 Masonry Wall Design 5/8/80 All power reactor facilities with an OL, except Trojan 80-10 Contamination of 5/6/80 All power reactor Nonradioactive System and facilities with an Resulting Potential for OL or CP Unmonitored, Uncontrolled Release to Environment 80-09 Hydramotor Actuator 4/17/80 All power reactor Deficiencies operating facilities and holders of power reactor construction permits 80-08 Examination of Containment 4/7/80 All power reactors with Liner Penetration Welds a CP and/or OL no later than April 7, 1980
.