ML19350B893
| ML19350B893 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/13/1981 |
| From: | Withrow G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-80-25, NUDOCS 8103231081 | |
| Download: ML19350B893 (4) | |
Text
- '
CORSumBIS Power Company General Offkes-212 West M*Ngon Avenue, Jackson, MkMean 49201 + (617) 7884650 March 13, 1981 g
W
/((
Mr James G Keppler
/
Office of Inspection and Enforcement Q
Region III h*
US Iluelear Regulatory Commission d "4 O fg8 4 [C 799 Roosevelt Road
{
/
3 Glen Ellyn, IL 60137 y
,v 9
DOCKET 50-155 - LICENSE DPR Y*
V BIG ROCK POINT PLA'iT - RESPOIiSE TO C
IE BULLETIN NC 80 OPERATIIiG PROBLE'E WITH TARGET ROCK SAFETY-RELIEF VALVES AT BWES IF Bulletin No 80-25 dated December 19, 1980, requested Consumers Power Company to take specific actions with respect to safety-relief valve operability. These actions were requested as a result of numerous events involving Target Rock (TR) safety-relief (S/R) valves.
The Big Rock Point (BRP) Plant design utilizes a reactor vessel / steam drum NSSS which has code safety valves on the steam drum. These safety valves are self-actuated " single stage" spring type relief valves manufactured by Crosby. The valves undergo a preventative maintenance program which involves valve repair and setpoint adjustment on a rotating basis such that all safety valves are maintained on an every third refueling outage basis.
In addition to the steam drum safety valves, the BRP plant design incorporates TR relief valves in a Reactor Depressurization System (RDS) which is used to depressurize the primary coolant system in certain accident scenarios to allev low pressure core cooling.
Inadvertant opening of the BRP TR relief valves vill not cause rapid primary system depressurization due to the presence of isolation valves preceding to the relief valves. Therefore, the BRP TR valves do not nrovide the same function as TR S/R valves at other BWRs. The Target Roc,k Capany has been contacted to determine the equivalency of the BRP TR relief valves and the TB S/R valves which are the subject of the bulletin. The BRP TB valves are unique in d? sign in that the upper stages of the valves are different from other TB S/h valves and electrically operated solenoids are used.
81032310 D Q
MAR. 1 6 1981
Mr James G Keppler 2
Big Rock Point Plant March 13, 1982 The above information was discussed with Mr D Foyd of your staff and it was determined the response to IE Bulletin No 80-25 for BRP need only address the TR valves in the RDS.
Therefore, the following information is provided in response to the three actions requested by the bulletin:
Action 1 If your facility has not yet installed or changed or is presently in the process of changing to the two-stage S/R valves, initiate appropriate quality control procedures to assure inspection of the solenoid actuators for excess Loc-tite prior to operation.
If the solenoid actuator manu-factured by Target Rock Corporation is already installed in your facility, confirm its operability either by its operational performance (ie., it has functioned as designed following an aging period of about 3 conths in the higher temperature environment of power operating conditions) or by functional testing at full pressure during the next refueling shutdown of the facility.
Include in your report the results of all attempts to operate the two-stage S/R valve (s).
Response
The actuators on the BRP TR valves are not assembled with any Loc-tite or other sealants.
The internal stages are enclosed in a pressure vessel that is seal velded.
The internal pilot disc is actuated by a magnetic field due to an external electric solenoid coil. Therefore, this action is net censidered applicable.
Action 2 In the event that a S/R valve, regardless of make or model (eg, both two or three stage), fails to function as designed, excepting for pressure set-point requirements, and the cause of the malfunction is not clearly determined, understood, and therefore corrected, standard operating procedures shall require that the entire valve be removed from service, disassembled, inspected, adjusted, and pressure setpoint tested with steam for proper operation prior to returning the valve to service. These overhaul requirements shall be at least equivalent to those applicable to periodic surveillance rehabilitation requirements.
Appro-priate revisions to your operating procedures shall be made to include these requirements.
Response
ERP TR valves are not pnue=atically operated and do not operate on any pressure setpoint. BBP Technical Specifications address limiting conditions of operation for failure either open or closed of the TR valves. Plant operating procedures hav~e been revised to require cceplete verification of operability based on IE Bulletin No 80-25 if any unexplained achnical failure occurs. Accept ance tests for the valves are required to be performed with air instead of steam due to the RDS design.
4 Mr Ja..es G Keppler 3
Lig Fock Pcint Plant March 13,19S1 Action 3 A review of your S/R valve pneumatic supply systems shall be perforced to determine the potential for and cagnitude of an overpressure condition.
The determined overpressure potential of the pneumatic supply shall be compared with the maximum operating pressure capabilities of the solencid actuator valves serving the S/R valves, so as to determine whether supply pressure could result in valve calfunction. Protective devices (such as relief valves) shall be installed in the proximity of the S/R valves and set to protect against supply pressure in excess of the operating pressure capabilities of the solenoid actuator device.
In addition, censideration should be given ta codification or replacement to reduce the sensitivity of the solencid actuator to pneumatic supply overpressure.
Further, the failure, either high or lov, of the pneumatic supply system shall be annunciated to the control room operator. The annunciated supply pressure should be measured at a location as close as practical to the S/R valves and downstream of any check valve connecting two or more pneunatic sources.
Appropriate operating procedures shall be provided to guide operator response to such an occurrence of high or low supply pressure.
Response
The BRP TR relief valves do not have pneumatically controlled solenoid actuators.
Therefore, this action is not considered applicable.
As described above, no modifications to the ERP TR relief valves or their actua-tion systems are required to address the actions of IE Bulletin No 80-25; there-fore, no modifications pertinent to the iters in this bulletin are warranted and no additional responses will be made.
U 0'
W Gregory C 'n'ithrow Senier Licensing Engineer CC Director, Office of Nuclear Reactor Regulation Director, Office of Inspection and Enforcement NRC Resident Inspector - Big Rock Point
CO::SUMERS POWER COMPA*iY Big Rock Point Plant IE Pulletin No 80-25 Docket Io 50-155 License No DPR-6 At the request of the Commission and pursuant to the Atenic Energy Act of 195L, and the Energy Reorganization Act of 197L, as acended and the Commission's Rules and Regulations thereunder, Consumers Power Co=pany submits our response to IE Bulletin I!o 80-25, dated December 19, 1980, entitled,
" Operating Problems with Target Rock Safety-Relier Valves at EWE's".
Consumerc Power Company's response is dated March 13, 1981.
CONSUMERS POWER COMPANY 0%
,i lllt $$f Y
By e,
R B DeWitt, Vice President Nuclear Operations Sworn and subscribed to before me this 13th day of March 19S1.
m -
IIelen I Dempski, Notary /ublic Jackson County, Michigan My comnission expires December IL, 1983
.