ML19330B879
| ML19330B879 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 07/18/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Stampley N MISSISSIPPI POWER & LIGHT CO. |
| References | |
| NUDOCS 8008070124 | |
| Download: ML19330B879 (1) | |
Text
[
'o UNITED STATES
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8 NUCLEAR REGULATORY COMMISSION 3
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' E [:. N 3
REGION il Y
101 MARIETTA ST., N.W., SUITE 3100
'(/4 ATLANTA, GEORGIA 30303 o
,2n Reply Refer To:
181S80 1-s J 50-416 0-4.17 Mississippi Power and Light Company ATTN:
N. L. Stampley Vice President of Production P. O. Box 1640 Jackson, MS 39205 Gentlemen:
The enclosed IE Supplement No. I to Bulletin No. 80-17 is forwarded to you for information. No written response is required. If your desire additional information regarding this matter, please contact this office.
Sincerely, f.C
\\
ames P. O'Reilly
' rector e' s;
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Enclosures:
1.
IE Suppledent No. I to Bulletin No. 80-17 2.
List of Recently Issued IE Bulletins cc w/ enc 1:
C. K. McCoy, Plant Manager aoo8 ora lM
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SSINS No.: 6820 Accession No.:
rm UNITED STATES 8006190027 V
NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 July 18, 1980 l
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 event.
Although we are essentially confident that the event was caused by water in the Scram Dischery Volume (SDV) system, we do not yet have a complete explanation as to why & water was present. The best estimate is that some type of blockage existed in % sent and/or drainage system for the SDV, precluding adequate drainage. W ensure that the SDV is empty, Browns Ferry (BF-3) has installed instrument *fnn to continuously monitor the water level in the scram discharge volume.
Sud instrumentation is being considered by other plants.
Since issumee of IE Bulletin 80-17, additional information has been identified.
Specifical%c-a)
At BrAsts Ferry a discrepancy was found *t etween the "as-built" scram dischatte-system and the "as-designed" system. An unused one-inch (1") instrument line was found uncapped on the four-inch (4") drain heades as the west side (the side whose rods scrammed) scram discharge volumeinst system of Unit No. 3.
It is believed that this line imprownthe venting, and therefore the drain time for that system.
b)
It hasfeen determined that the vent systems on some scram discharge volumethterconnect with vent headers that are also common with and are camatted to other systems. The interconnected " vent" systems may comin water drained or being drained from those other systems.
This uer could potentially affect performance of the SDV. Also, both tJevent and drain systems' for the scram discharge system may contaieng lengths of relatively small bore piping. Designs specify a verymdual slope, such that small errors in the ' as-installed" ii P P ngeuld result in degraded performance (for example, due to loop ais).
c)
Concem have been expressed within the NRC Staff regarding potential delays 2r, may occur before start of injection of boron into the BWR systes9A the Standby Liquid Control System (SLCS) when this manual operaFaction is required. The potential delays could be caused by
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e 4
fs IE Bulletin No. 80-17 July 18, 1980
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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" SDV system and associated vent and drain systems, including any identified design deficiencies.
Include copies of verified "as-built" isometric drawings of the SDV 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
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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 volumes until continuous monitoring system (s) (discussed in B.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 continuously 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.
q_j Provide a written description of the system design to the NRC Regional Office.
4 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)
Documentationindetailwhytheinstall$tioncannotbe 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 inc,1ude 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 submitted to the NRC Regional Office.
We have been told that meetings have 3
("J already been scheduled by GE to discuss their proposals in this area N
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 Operations 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.
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- IE Bulletin No. 80-17 Enclosure
()SupplementNo.
1 July 18, 1980 RECENTLY ISSUED IE BULLETINS Bulletin Subject Date Issued Issued To No.
'80-17 Failure Of Control Rods To 7/3/80 All BWR power reactor Supplement 1 Insert During A Scram At A facilities holding BWR OLs for ACTION and all BWR power reactor facilities holding CP for Information.
80-17 Failure Of Control Rods To 7/3/80 All BWR power reactor 4
Insert During A Scram At A facilities holding BWR OLs for ACTION and all BWR power reactor facilities holding CP for Information.
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
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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 f
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 7_)s
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Deficiencies operating facilities and holders of power reactor construction permits
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