ML20043G256

Proposed Tech Spec 4.7.6 Re Control Room Area Ventilation Sys

ML20043G256
Person / Time
Site:	Catawba
Issue date:	06/12/1990
From:	DUKE POWER CO.
To:
Shared Package
ML20043G253	List: ML20043G251 ML20043G256
References
NUDOCS 9006200099
Download: ML20043G256 (1)

Text

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• PLA.NT SYSTEMS g M L BASES 3/4.7.5 STAN08Y NUCLEAR SERVICE WATER POND

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The limitations on the standby nuclear service water pond (SNSWP) level

• 3 d f and temperature ensure that sufficient cooling capacity is available to either:

]f .3 h ,(1) provide normal cooldown of the facility, or (2) mitigate the effects of accident conditions within acceptable limits.

C'C The limitations on minimum water level and maximum temperature are based on providing a 30-day cooling water supply to safety-related equipment without 0o 4 @J c exceeding its design basis temperature and is consistent with the g]d .

u ations of Regulatory Guide 1.27, " Ultimate Heat Sink for Nuclear Plants," ,

gg March 1974.

P* C The peak containment pressure analysis assumes that the Nuclear Service  :

hQ.b]d+.

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..o G-Water (RN) flow to the Containment Spray and Compo' ant Cooling heat exchangers has a temperature of 86.5'F. This temperature is important in that it, in l part, determines the capacity for energy removal from containment. The peak Q

> f0 [g heat) ' containment is balanced by energy pressure occurs removal from these heat exchangers.when This energy balance additio

' f g t. recirculation and after ice melt.W is reached far out in time, after the transition from g 0,,

Because of the effectiveness of the ice bed o g g,3 in c ndensing the steam which passes through it, containment pressure is -

0j o insensitive to small varia% ons in containment spray temperature prior to ice .

,4 moltout.

d

- M]3 02 To ensure that the RN temperature assumptions are met, Lake Wylie temperature is monitored. During periods of time while Lake Wylie temperature +

is greater than 86.5'F, the emergency procedure for transfer of ECCS flow rdw paths to cold leg recirculation directs the operator to align at least one

%do train of containment spray to be cooled by a loop of Nuclear Service Water i

V .- which is aligned to the SNSWP. t o 3/4.7.6- CONTROL ROOM AREA VENTILATION SYSTEM t .t o f The OPERABILITY of the Control Room Area Ventilation System ensures that:

1 the ambient air temperature does not exceed the allowable temperature for

. $+ o 0 oocr- .,j,j c system, (on)tinuous-duty and (2) the control room willrating for the remain habitable equipment for operations personnel and i

$ 0 ,.o o during and following all credible accident conditions. Operation of the  :

p Mi p system with the heaters operating to maintain icw humidity using automatic M.s c c control for at least 10 continuous hours in a 31-day period is sufficient to 0 - reduce the buildup of moisture on the adsorbers and HEPA filters. The 3

I 3. wo[. OPERABILITY is based on limiting of this the system radiationin conjunction exposure with control to personnel room occupying thedesign control provisionsl i

CO This limitation is con- '

% O ro g p  % room sistentto with 5 the rems or less whole requirements body, of General or itsCriterion Design equivalent. 19 of Appendix A,

g % $ 10 CFR Part 50. ANSI N510-1980 will be used as a procedural guide for surveil-1 -

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