ML19329G278
| ML19329G278 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 06/12/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Martin T Public Service Enterprise Group |
| References | |
| NUDOCS 8007140284 | |
| Download: ML19329G278 (1) | |
Text
Yk p nRtioq jo,,
UNITED STATES c
8 NUCLEAR REGULATORY COMMISSION g
- r. g'n
- j REClON I g
631 PARL AVENUE 0
4'5 g
KING OF PRUSSIA,i ENNSYLVANI A 19406 4 **...
Docket Nos. 50-354 June 12, 1980 50-355 Public Service Electric & Gas Company ATTN: Mr. T. J. Martin Vice President Engineering and Construction 80 Park Place Newark, New Jersey 07101 Gentlemen:
.The enclosed IE Bulletin No. 80-14, " Degradation of Scram Discharge Volume Capa-bility," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, CA Boyce H. Grier Director
Enclosures:
1.
List of Recently Issued IE Bulletins CONTACT:
D. L. Caphton (215-337-5266) cc w/encls:
E. N. Schwalje, Manager - Quality Assurance,
~
Engineering and Construction Department 8 0.0 714 0 2N q
ENCLOSURE 1 SSINS No.:
6820 Accession No.:
UNITED STATES 8005050056 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 u
i June 12,' 1980 IE Bulletin No. 80-14 Page 1 of 2 DEGRADATION OF BWR SCRAM DISCHARGE VOLUME CAPABILITY During our review of BWR operating experience, two events have raised concern on ooeratici s related to the control rod drive system scram discharge volume (SDV').
4 Description of Circumstances:
At Hatch Unit 1, on June 13, 1979, while performing surveillance to func-two switches (C11-N013A, B) were found tionally test SDV high level switches,(C11-N013 C, D) were operable.
to be inoperable.
Redundant switches The reactor was s i.ne refuel mode and these switches had been modified prior to this occurrence.
Inspection of the inoperable level switches revealed that the float rod was bent and binding against the side of the float chamber on both switches.
The licenJae believes that the float rods were bent during or prior to initial installat M ind that metal particles from the modification i
caused binding of the float.
(LErt 79-038)
Brunswick Unit 1 reported that slow closure of the SDV drain valve during a reactor scram on October 19, 1979 apparently caused a water hammer event which damaged several pipe supports on the SDV drain line.
Drain valve closure time was approximately five minutes due to a faulty solenoid controlling air supply to the valve.
The damaged pipe supports were repaired but repair parts for the faulty solenoid were not available.
To prevent possible damage from a scram, the unit started up with the SD? vent and drain valves closed e:. cept for periodic draining.
During this mode of operation the reactor scrammed from high level in the SDV,' without prior actuation of either the high level alarm or rod block switch.
Subsequent inspection revealed that the float bail on the rod block switch was crushed and the float ball stem on the high level alarm switch was bent such that the switches would not operata.
The water hammer event discussed above was the reported cause of failure of these two switch assemblies.
(LER79-74)
As a result of these events and related anticipated transients without scram
~
(ATWS) studies, concern arises that the SDV function may be degraded by the undetected presence of fluid in the SDV.
The second event is significant in that it indicates the potential for a common cauze failure (faulty solenoid) to result in operation of the SDV in a manner which could defeat both the level switch function and the SOV draining function.
The ATWS generic studies (NUREG 0460) have led the staff to propose, among other requirements, improve-ments in the SDV designs to reduce susceptibility to ' common cause failures.
c By separate correspondence, the staff will provide example Technical Specifica-n l
tions related to the action items discussed below.
IE Bulletin No. 80-14 June 12, 1980 Page 2 of 2 A.
GE BWR's With an Operating License The-following actions are to be ta. ken by licensees of GE designed BWR facilities with an operating license:
1.
Review plant records for instances of degradation of any SDV level switch which was or may have been caused by a damaged or bent float assembly.
Identify the cause and corrective action for each instance.
2.
Review plant records for instances of degradation of SDV vent and drain valve operability.
Provide the closure times required and typically observed for these valves and the basis for the required closing times.
Identify the cause and corrective action for each instance of degradation.
3.
By procedures, require that the SDV vent and drain valves be normally operable, open and periodically tested.
If these valves are not operable or are closed for more than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period during operation, the reason shall be logged and the NRC notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Prompt Notification).
4.
Review instances in which water hammer or damage which may have been caused by water hammer has occurred in SDV related piping.
Identify the cause and corrective action for each instance.
5.
Review surveillance procedures to ensure that degradation of any SDV level switch due to a damaged float or other cause would be detected and that.inoperability from any cause would be reported to the NRC.
6.
If no functional test or inspection which would detect degradation of each SDV level switch has been performed during the past 3 months, make provisions to. perform an inspection and functional test of all SDV level switch assemblies at the next reactor shutdown of greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> duration.
B.
Reporting Requirements The action taken in response to the items in Part A shall be completed and a written report on the results submitted to the NRC within 45 days from the date of this Bulletin.
This report should be submitted to the Director of the appropriate NRC Regional Office and a copy should be forwarded to the NRC Office of Inspection and Enforcement, Division of Reactor Operations Inspection, Washington, D.C.
20555.
l Approved by GAO, B180225 (R0072); clearance expires 7-31-80.
Approval was given under a blanket clearance specifically for identified generic problems.
i L
l-
- s..
IE Bullctin No. 80-14
. June 12, 1980 RECENTLY ISStlED IE BULLETINS Bulletin Subject Date Issued Issued To ':o.
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 Operability OL 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 facili-ties and holders of power reactor construction permits 80-08 Examination of Containment 4/7/80 All power reactors Liner Penetration Welds with a CP and/or OL no later than April 7, 1980 80-07 BWR Jet Pump Assembly 4/4/80 All GE BWR-3 and Failure BWR-4 facilities with an OL 79-03A Longitudinal Weld Defects 4/4/80 All Power Reactor in ASME SA-312, Type 304 Facilities with an Stainless Steel Pipe OL or CP 80 Engineered Safety Feature 3/13/80 All power reactor
'(ESF) Reset Controls-facilities with an OL 80-05 Vacuum Condition Resulting 3/10/80 All PWR power In Damage To Chemical Volume reactor facilities Control System (CVCS) Holdup OLs and to those Tanks-with a CP 79-018 Environmental Qualification 2/29/80 All power reactor of Class IE Equipment-facilities with an OL
-..