ML19257A192
| ML19257A192 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 12/28/1979 |
| From: | Moody D Maine Yankee |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0578, RTR-NUREG-578 WMY-79-150, NUDOCS 8001020434 | |
| Download: ML19257A192 (4) | |
Text
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December 28, 1979
' ' JO B.3.2.1 R1Y 79-150 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention: Office of Nuclear Reactor Regulation Mr. Harold Denton, Director
References:
(a) License No. DPR-36 (Docket No. 50-309)
(b) NUREG 0578 - Lessons Learned Task Force Status Report and Short Term Recommendations dated July, 1979 (c) USNRC Letter to All Operating Nuclear Power Plants dated September 13, 1979 (d) USNRC Letter to All Operating Nuclear Power Plants dated October 30, 1979 (e) MY Letter to USimC dated April 26, 1979 (f) MY Letter to USNRC dated May 4,1979
Dear Sir:
Subject:
NUREG-0578, Item 2.1.4 Containment Isolation Reference (d) in addressing recommendations relative to reference (b) item 2.1.4, requested that a determination be made of systems which are considered to be essential and those which are considered to be non-essenital as they relate to a containment isolation system design, and that, the results of that determination be submitted to the NRC for review.
References (e) and (f) previously provided information to the NRC in response to I&E Bulletin No.79-06B relative to those systems which could potentially transfer radioactive gasses and liquids outside the containment.
An evaluation has been performed of those lines which are isolated on a containment isolation signal to determine whether they can be safely isolated on a safety injection actuation signal.
The results of that evaluation and justification for classifying certain systems as essential are therefore provided.
The valves have been classified as follows:
NON-ESSENTIAL Service Location Inside Outside Component cooling from H.P. drain TV-34101 TV-34111 cooler, pressurizer quench tank cooler, neutron shield tank ccoler.
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1 Valves which have DC solenoids.
9001020 NbN
United States Nuclear Regulatory Commission December 28, 1979 Attention:
Mr. Harold Denton, Director Page 2 NON-ESSENTIAL Service Location Inside Outside Primary demineralized water to TV-30071 quench tank.
Pressurizer quench tank pump TV-30021 TV-300ll discharge.
Containment sump pump discharge.
TV-3303 TV-33041 Steam generator continuous TV-2601,2,31 blowdown.
Purge duct exhaust.
HCV-6006,7,8 Safety injection test and safety HCV-351K HCV-350K injection tanks liquid sample.
Component cooling from penetration TV-34131 coolers.
Component cooling from CEA drive TV-34161 TV-34171 mechanism coolers.
Purge duct supply.
HCV-6005,9 Primary vent header.
TV-330ll TV-33021 Air monitor sample (In)
TV-20061 Air monitor sample (Out)
TV-2001 TV-20021 Containment leak detection.
TV-20031 &
TV-2004 1 Pressurizer steam interface and TV-3501 TV-3506 S.V. samples.
R.C. loop liquid sample.
TV-3503, 3504, TV-3507A 3505 Pressurizer liquid sample and TV-3502, 3508 TV-3507B surge line sample.
Excess flow check valve drains TV-26051 to blowdown tank.
Steam line drains to condenser.
TV-26041 1663 278
United States Nuclear Regulatory Commission December 28, 1979 Attention:
Mr. Harold Denton, Director Page 3 NON-ESSENTIAL Service Location Inside Outside High pressure drain cooler outlet.
HCV-257 Decay heat release valve.
HCV-1001 Steam supply to auxiliary feed TV-11021 pump.
Containment service air supply.
2012 Nitrogen supply.
29041 Carbon dioxide.
29061 29071 ESSENTIAL Components cooling water from TV-34141 TV-34151 RCP's.
Containment air recirculation TV-3412 cooler water outlet.
8 k
Seal water from RCP's.
HCV-251 HVC-259K
- l HCV-261 N
HCV-271 SAFETY EVALUATION:
The valves listed above are part of the containment boundary and are therefore Safety Class 2 equipment.
Isolating the NON-Essential valves on a Safety Injection Actuation Signal does not create an Unreviewed Safety Question.
The latching requirement on valves having DC solenoids will be addressed in another memo.
Containment Isolation Justification of Non-ECCS Systems as Essential Component Cooling Water from RCP's TV3414 and 3415 Seal Water from RCP's HCV-251, 261, 271 and 259K i
It is essential that these valves remain open to insure long term operability and seal integrity of the reactor coolant pumps.
I Containment Air Recirculation Cooler Water Outlet TV-3412 This valve trips on a containment spray actuation signal.
The containment air recirculation coolers provide containment cooling until the spray system is actuated by the containment spray actuation signal.
1663 279
United States Nuclear Regulatory Commission December 28, 1979 Attention:
Mr. Harold Denton, Director Page 4 We trust that this information is satisfactory; however, if you have additional questions, please contact us.
Very truly yours, MAINE YANKEE ATOMIC POWER COMPANY
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Y D.
Moody Manager of Operations EWJ/dmp 1663 280
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