ML19268C047
| ML19268C047 | |
| Person / Time | |
|---|---|
| Issue date: | 11/28/1979 |
| From: | Butcher E Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7912190634 | |
| Download: ML19268C047 (2) | |
Text
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f-UNITED STATES
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NUCLEAR REGULATORY COMMISSION 2
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f W ASHINGTON, D. C. 20555 e
NOTE T0:
See Distribution Sheet FROM:
E. Butcher, Plant Systems Branch, DOR
SUBJECT:
GUIDELINES FOR EVALUATING QUALIFICATION OF CLISS :E ELECTRICAL EQUIPriENT IN OPERATING REACTORS The enclosure to the memorandum issued November 13,1971 :f :.ne s
.me subject, contained an omission on page 7 which should be ad:t: o yCJr i
copy. The phrase, "or delayed. initiation", should be added as shown on the attached copy.
E. Butcher Plant Systems Bran:h Division of Operating eactors
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rg gin) D C ( 3k
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- ontainment Scravs - Equipment exposed to chemical so*ays snould be
- ualified for the mest severe chemicsi environment ~a:idic :-
- asic) which could exist, Deminerali:ed water spra s shoul: not
- e exempt from consiceration as a potentially acverse service condition.
4.2 Service Conditions for a PWR Main Steam Line Break (MSLE) Inside Containment
' Ecui: ment required to function in a steam line break environmen; must be cualified for the high temperature and pressure that ::uid result.
In some cases the environmental stress on exposed equi? er.-
ty :e higher than that resulting from a LOCA, in others it ma be ne rcre severe than for a LOCA due to the automatic operation of a containment spray system.
1.
Temperature and Pressure Steam Conditions - Eouipmen; qualified for a LOCA environment is considered qualified for a MSL3-accident environ-ment in plants with automatic spray systems not sub.dect :: :isabling single componen: failures.
This position is casec :a - e "5es:
Estimate" calculation of a typical plant peak tempe at.:re and pressure and a thermal analysis of typical components inside containment.E The final acceptability of tnis approach, i.e., use of :ne "Best Estimate",
is pencing the completion of Task Action Plan A-21, Main Steamline Break Inside Containment.
Class IE equipment installed in plants without automatic spray systems or plants with spray systems subject to disaoling single
'ailures or delayed initiation should ce qualified #: r a MI.3 accident i vironment de: ermined by a plant specific ana'.ysi!.
- E: able methods
'See W3E3 ^ 55. Sh:
"em Safe:v Assessra"? On-eI*
'*M' O a#ication of $d#et/-Eela eo Ilectrical EQuiO~eM
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Ist**"Ps, for a "' ore Oe:ai5 ed discussion o# the 0E5*.
i'~#~3'i Il Ok 5* 00-
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