ML20003F598
| ML20003F598 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 04/20/1981 |
| From: | Withrow G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8104230107 | |
| Download: ML20003F598 (4) | |
Text
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y Power j company 7:,,
p~D o.a.c.i oene.s: 212 w.st Michigan Avenue, Jackson, MI 49201 e (517) 7884550 April 20, 1981 S'
ug APR221993w}
s"% w p/s Director, Nuclear Reactor Regulation 4'b/
/
Att Mr Dennis M Crutchfield, Chief Operating Reactors Branch No 5 g4 US Nuclear Regulatory Consission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - CONTAIIB.ENT PURGE AND VENT VALVE MECHANICAL OPERABILITY NRC letter dated February 27, 1981 requested additional information with respect to the rechanical operability of the containment purge and vent valves. Attach-ment 1 to this submittal provides Consumers Power Company responses to these requests in the same format as presented in that letter's enclosure.
Gragory C Withrow (Signed)
Gregory C Withrov Senior Licensing Engineer CC Dir!ctor, Region III, USNRC NRC Resident Inspector - Big Rock Point pages 8104230 M P
9 Attachment' 1 CONSUMERS POWER COMPANY RESPONSE TO:
NRC REQUEST FOR ADDITIONAL INFORMATION BIG ROCK POINT NUCLEAR PLANT CONTAINMENT PURGING DURING NORMAL PLANT OPERATION MECHANICAL OPERABILITY DD!ONSTPATION 1.0 Allis Chalmers 2h.0" Butterfly Valves 1.1 Describe the extent to which the valve assembly is seis=ically qualified?
Response: The original purchase documentation did not include specific seismic design criteria. However, the valves have been certified to withstand the design basis LOCA stresses inposed on the= during closure without incurring any disabling damage.
Seismic qualification vill be addressed in Syste=1. tic Evalua-tion Program Topic III-6, entitled, " Seismic Design Considera-tions".
1.2 Described the extent to which the pilot solenoid valves are seis=ically qualified and environmentally qualified for long term exposure to the normal plant environment. If the purge valves are to be operative post-LOCA, described the extent to which the solenoid valves are environmental-ly qualified for the LOCA envirorr.ent. Do the elastomeric parts, sole-noids, etc. have a qualified design life where periodic replace =ent of parts is required?
Response: The solenoid valves for all the ventilation valves are located outside containment. Each pair of solenoid valves control two valves (eg, SV 9151 and 52-both supply valves; SV 9153 and Sh-both exhaust valves). The containment is normally ventilated; therefore, the purge valves are required to operate post-LOCA for containment isolation and vacuum relief functions.
Environ = ental qualification information is provided for the sole-noid valves by Consumers Power Co=pany submittals dated October 31, 1980; January 30, 1981; and March 2,1981 (pages 1L, lh6, lh7 and 1h8) which provide the Environmental Qualification of Electrical Equipment bases. The preventative maintenance prcgram rebuilds the solenoid valves about every five years during a refueling outage.
The solenoid valves are located on the C-26 panel in the venti-lation shed. The panel is seismically qualified as outlined in Attechment I of Consumers Power Company submittal dated January 22, 1981.
Describe the extent to which the operators are seismically qualified and 1.3 environmentally qualified for long term exposu:e to the normal plant en-viron=ent? If the purge valves are to be operative post-LOCA, describe the extent to which the operators are environmentally qualified for the Do the elastomeric parts in the cperator have a quali-LOCA envirsu=ent.
fled design life where periodic replace =ent is required?
Attcch=ent 1 2
Response: The response for item 1.2 identified that the solenoid valves for all of the ventilation valves are located outside contain=ent. This is also true for the location of the operators for all of the ventilation valves. This reduces the harshness of the parameters associated with the LOCA environe=tn.
Seis=ic and environ = ental qualification for the valve operators vill be addressed in Syste=atic Evaluation Progra Topics III-6 and III-11.
1.h Do the elasto=eric parts in the valve body have a qualified design live?
Are they required to be replaced periodically?
Response: A qualified design life for the valve body elastomeric parts has never been established. However, the butterfly valve seats are on a preventative maintenance progra= which replaces then every two to three years during a refueling outage.
1.5 Have the manufacturer's reco== ended preventive maintenance instructions (lubrication, etc.) been reviewed for the valvc, operator and solenoids and are they being followed?
Response: The rep. ace =ent of the valve seats and rebuilding of the sole-noids are addressed in the responses to items 1.2 and 1.h.
No lubrication of the operator is required. The above two preven-tative =aintenance ite=s are more restrictive that the manufac-turer's reco== ended preventative maintenance practices.
1.6 Provide an assessnent of the structural capability of any ducting or pip-ing in the purge syste= which is upstrea= or downstre1= of the valves and is exposed to the flow condition associated with the LOCA and the seis=le event. The staff is particularly interested in the effects that loose debris from the pipe or duct syste= =ay have on the closure capability of these valves.
Response: The redundancy provided in the ventilation syste= by the use of in-series butterfly and sving check valves provides assur-ance of contain=ent isolation in the event of da= age to a valve.
The possibility of loose debris fro = ducting or piping failure resulting in valve inoperability is considered lov. Contain=ent isolation would likely be guaranteed because the butterfly valves vould block' debris before it could reach the sving check valves.
If preventative =easures such as screening or grating vere used, these preventative devices could become loose debris. Therefere, we do not propose any changes from the current design.
2.0 Atwood & Morril 2L.0" Swing Check Valves 2.1 Describe the extent to which the valve assembly is seis=ically qualified?
Response: The response for item 1.1 applies here also.
3 2.2 Describe the extent to which the pilot solenoid valves are seismically _
e-qualified and environmentally qualified for long term exposure to the normal plant environment. If the purge valves are to be operative post-LOCA, describe the extent to which the salenoid valves are environmental-ly qualified for the LOCA environment. Do the elastomeric parts, sole-noids, etc. have a qualifed design life where periodic replacement of parts is required?
Response: The response for item 1.2 applies here also.
Describe the extent to which the operators are seismically qualified and 2.3 environmentally qualifed for long term exposure to the normal plant en-vironment? If the purge valves are to be operative post-LOCA, describe the extent to. which the operators are environmentally qualified for the LOCA environment. Do the elastomeric parts in the operator have a quali-fied design life where periodic replacement is required?
Response: The response for item 1.3 applies here also.
2.h Do the elastomeric parts in the valve body have a qualified design life?
Are they required to be replaced periodically?
A qualified design life for the valve body elastomeric parts
Response
has never been established. However, the swing check valve seats are on a preventative naintenance program which requires cleaning and inspection of the seat and seating surface every two to three years during a refueling outage.
Have the manufacturer's reco== ended preventive maintenance instructions 2.5 (lubrication, etc.) been reviewed for the valve, operator and solenoids and are they being followed?
The inspection of the valve seats and rebuilding of the
Response
solenoids are addressed in the responses to items 2.~2 and 2.h.
No lubrication of the operator is required. The above two preventative maintenance items are more restrictive than the manufacturer's recommended preventative maintenance prac-tices.
Provide an assessment of the structural capability of any ducting or pip-2.6 ing in the purge system which is upstream or downstream of the valves and is exposed to the flow condition associated with the LOCA and the seismic The staff is particularly interested in the effects that loose event.
debris from the pipe or duct system may have on the closure capability of these valves.
Response: The response for item 1.6 applies here also.
. _.,.