ML17326B188

Revised Tech Spec Section 3/4.4.9 Re RCS Pressure/Temp Limit Bases

ML17326B188
Person / Time
Site:	Cook
Issue date:	08/01/1985
From:	INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
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ML17326B189	List: ML17326B188 ML17334A903
References
NUDOCS 8508080445
Download: ML17326B188 (11)

Text

ATTACHMENT 1 AEP: NRC: Q894G

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REACTOR COOLANT SYSTEM~

BASES 3 4.4,9 PRESSlJRE/TEMPERATURE LIMITS hll components in the Reactor Coolant System are designed to vith-stand the effects af cyclic laads due to system temperatuxe and pressure changes. These cyclic loads are introduced by normal load transientsf reactor trips, and startup and shutdown operations. The variaus categozics of load cycles used or. design purposes are provided in Section 4.1..4 af the fSAR. During startup and shutdown, the rates of temperature and

. pressure changes are limited so that the maximum specified hcatup and cooldown rates arc consistent vith thc design assumptions and satisfy the stress limits for cyclic operation.

hn KD or OD one~arter thickness surface flav,is postulated at the location in the vessel vhich is faund to be the limiting case. Thexe are sevezal factors vhich influence the postulated location. The thermal induced bending stzess during heatup is compressive an the inner surface while tensile on the autez surface of the vessel wall.'uring caoldavn

'the bending stress profile is revexsed. In additian, the matexial tough>>

ness is dependent upon irradiatian and temperature and thezefore the fluence pzofile through the reactor vessel vali, the rate af heatup and also the rate of coaldown influence the postulated flav lacation.

The heatup limit cuzvc, Figuxe 3.4-2, is a composite curve vhich vas prepared by determining the most conservative case", vith either the inside ar outside vali controlling, for any heatup rate up to 60 P pez houx.

The caoldovn 'limit curves of Figure 3.4-3 are composite curves which vere prepared based upon the same type analysis vith the exception that the controlling lacation is alvays the inside vali where the cooldovn thermal gradients tend ta produce tcnsilc stzesses while producing compressive stresses at the autside vali. The heatup and cooldown cuzves vere pre-pared based upon the most limiting value of the predicted adjusted reference temperature at. the end of 12 EFPY.

Reactor irradiation will cause

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operation and resultant fast: neutron (E 1 Mev) an increase in the RT . Therefore, an adjusted reference temperature, based upon theNDFluence and copper and phosphorus content of the material must be predicted. The heatup and cooldown limit curves of Figures 3.4-2 and 3.4-3 include predicted adjustments for this shift in RT>>T at thy end of 12 EFPX, as well as adjustments for possible errors xn the pressure and temperature sensing instruments.

D. C. COOK - UNIT 1 S 3/4 4-6 Amendment Ho.

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INTENTIONALLY LEFT BLANK D. C. COOK UNIT 1 B 3/4 4-8 Amendment No.

INTENTIONALLY LEFT BLANK D. C. COOK UNIT I B 3/4 4-9 Amendment No.

INTENTIONALLY LEFT BLANK D. C. COOK UNIT 1 . B 3/4 4-10 Amendment No.

f' INTENTIONALLY LEFT BLANK D. C. COOK UNIT 1 B 3/4 4-11 Amendment No.