ML19330B857
| ML19330B857 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/18/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8008070081 | |
| Download: ML19330B857 (1) | |
Text
_
f em
- pn uruq%
a UNITED STATES E
1, NUCLEAR REGULATORY COMMISSION
.E REGION ll 101 MARIETTA ST,, N.W., SUITE 3100 ATLANTA, GEORGIA 30303 (q <
v In Reply Refer To:
RIT-Tpo jg g p
-E 50-259 50-260
-296 Tennessee Valley Authority ATTN:
H. G. Parris Manager of Power 500A Chestnut Street Tower II Chattanooga, TN 37401 Gentlemen:
Enclosed is IE Supplement No. I to Bulletin No. 80-17 which requires action by you with regard to your power reactor facility (ies) with an operating license.
In order to assist the NRC in evaluating the value/ impact of each Bulletin en licensees, it aculd be helpful if you would provide an estimate of the manpower expended in confuct of the review and preparation of the report (s) required by the Bulletin. Rease estimate separately the manpower associated with corrective actions necessary following identification of problems through the Bulletin.
Should you have 2ny questions regarding this Bulletin or the actions required by (3
you, please ccn12 art this office.
u)
Sincerely, O~
amut.L J mes P. O'Reilly Di ector
Enclosures:
1.
IE Supplemat No. I to Pulletinfo. 80-17 2.
List of Reantly Issued IE Bulldus cc w/ encl:
H. L. Abercroiisie, Plant Superintendent R. E. Rogers, assject Engineer H. N. Culver, Ef, Nuclear Safety Review Staff
,O V
THIS DOCUMENT C0tlTMNS P00R QUAUTY PAGES 8 0 0 8 0 'Z 0 03l g
h SSINS No.:
6820 Accession No.-
pd UNITED STATES 8006190027 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 July 18, 1980 IE Bulletin No. 80-17 1
Supplement No. 1
. FAILURE OF 76 OF 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 ue 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 instrumentatiN1 to Continuously monitor the water level in the scram discharge volume.
Sudh instrumentation is being considered by other plants.
Since issuanat of IE Bulletin 80-17, additional information has been identified.
Specifically:
a)
At Browus, Ferry a discrepancy was found between the "as-built" scram dischar,y system and the "as-designed" system. An unused one-inch (1") innamment line was found uneapped on the four-inch (4") drain header mm.tbe west side (the side whose rods scrammed) scram discharge volume vent system of Unit No. 3.
It is believed that this line improved tAe venting, and therefore the drain time for that system.
b)
It hasNena determined that the vent systems on some scram discharge volumes;hnarconnect with vent headers that are also common with and are en==w"*d to other systems. The interconnected " vent" systems may casterm water drained or being drained from those other systems.
This uwar could potentially affect performance of the SDV. Also, both theaant and drain systems for the scram. discharge system may contaimlneg lengths of relatively small bore piping. Designs specify a veryapukal slope, such that small errors in the "as-installed" piping 2auM result in degraded performance (for example, due to loop anssL c)
Concerashone been expressed within the NRC Staff regarding potential delays.sut amy occur before start of injection of boron into the BWR system :hou the Standby Liquid Control System (SLCS) when this manual operatoracdon is required. The potential delays could be caused by O
L
P f~)
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" SDV system and associated vent and drain systems, incloffryg any identified design deficiencies.
Include copies of verified "as-built" isometric drawings of the SDV and detailed desarlptions of the remainder of the system, verified to be correct, as pit of this analysis.
2)
Revhe and implement Operating Procedures as necessary to provide clear guidance to the licensed operator in the control room regarding whesse should initiate the SLCS without obtaining prior supervisory appemml. Provide a description of the implemented procedural
()s regsUresents.
3)
Assue that procedures exist and are implemented for specifying remnual action to be taken if water is found in the SDV system at thus when it should be free of water.
Provide a description of the implemented procedural requirements.
4)
Revse and implement administrative procedures as necessary to ensure thaitic SLCS key shall be readily available to the licensed operator inins control room.
Provide a description of the implemented pro-ceduwI requirements.
5)
Conthme daily monitoring of water levels in all scram discharge 1
volmws until continuous monitoring system (s) (discussed in B.1 beled is- (are) installed and operational (this requirement supes, des the requirements of Item 5 of IE Bulletin 80-17 which regeked daily surveillance for only 6 days).
B.
Actions tabe Taken by BWR Licensees and Completed by September 1,1980:
1)
Iarb& a system to continuously monitor water levels in all scram dianaqrt volumes.
Continuous recording and alarm features must be inchdd in the design. Consideration should be given to use of divear level sensors in this (these) system (s).
The design installed shadFrepresent the design with the highest level of reliability
(~}
ncampMhle with completion of installation by September 1,1980.
Pxandra written description of the system design to the NRC Regional OfEhr j
1
e 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, independeht 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 submitted to the NRC Regional Office. We have been told that meetings have
()
already been scheduled by GE to discuss their proposals in this area i
with licensees.
Additional requirements are under consideration and will be the subject of further communication from NRC.
I Licensees of all operating BWRs shall submit the information requested within the specifieg 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 perim4s specified above, written statements of the above information signed under ondt or affirmation. Reports shall be submitted to the Director of the appropiate NRC Regional Office and a copy forwarded to the Director, Division of 3kactor Operations Inspection, NRC. Office of Inspection and Enforcement,nhshington DC 20555.
Approved by EhB, B180225 (R0071); clearance expires 7-31-80.
Approval was given undera &Janket clearance specifically for identified generic problems.
m
/
r-*-
w
T P
IE Bulletin No.-80-17 Enclosure Supplement No. I' July 18, 1980
()
RECENTLY ISSUED IE BULLETINS i
Bulletin Subj ect 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 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 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
... -