ML20128C317

Forwards Request for Addl Info to Enable NRC to Continue Review of Util 751201 Request for Change in Main Steam Line Low Pressure Setpoint

ML20128C317
Person / Time
Site:	Monticello
Issue date:	01/29/1976
From:	Eisenhut D Office of Nuclear Reactor Regulation
To:	Goller K Office of Nuclear Reactor Regulation
References
NUDOCS 9212040337
Download: ML20128C317 (2)

Text

. _ . _ - -

)

i l

j JAN 2 91976 s '

i DOCKET NO 0-263 i I t

)

1 i

Karl R. Goller. Assistant Director for Operating Reactors. 00R Plant Name: Monticello Docket No.: 50-263 PROJECT BRANCH ORB-2 AND PROJECT MANAGER: R. Snaider REVIEW BRANCH: Reactor Safety Branch

!4

, REVIEW STATUS: Awaiting information 4

Additional information is required to continue our review of Northern States Power Company's letter of December 1.1975 in which they requested a change in the main steam line low pressure setpoint and a change in the operating MCPR limits for 8x8 and 7x7 fuel. The request for additional information is attached as i enclosure 1.

l

Oristnal 81gned by i

D*TPell 0 Eisenhut i

Darrell G. Eisenhut, Assistant Director l 9212040337 760129 for Operational Technology PDR ADOCK 05000263 Division of Operating Reactors

P PDR i

Enclosure:

l As stated I

i cc: .R. Baer j j R. Snaider j

i B. Grimes D. Ziemann i

! DISTRIBUTION:

, Central Files Docket Files (50-263)

} NRR Reading

! i RSB Reading

! I BBuckley -

DEisenhut OT Branch Reading

, OT Technical Assistant .. . gd/ ,

w yv.{p my a ria

• OR:F'

.0R: ._ OR:EEBL -.0R:Ay 0T. _ _

! .u~~=+- BCBtek ey.-. RBa ._ ._BGrimes_ DEisenhut _ _ . _

! . .n

• 3M2./76 1/2[/76 _1/f8/76 1/)$76 l l rca, ac.m <an. ,.m ucu om _

• u..... n ..... , m .,m . ..,,u,....... ...

L L .- .

r .

1. For the spectrum of steamline breaks downstream of the main steamline isolation valves (MSIV) provide the following:

(a) An analysis of the change in the radiological consequences resulting from the reduction in the setpoint for MSIV j closure on low steamline pressure from 850 psig to 825 psig.

So that we may perform an independent check, also provide the difference in the amount of steam and liquid released

as a result of the lower setpoint.

! (b) A discussion of the effects of the setpoint reduction on j peak cladding temperature and MCPR.

2. In the analysis of the failure of the turbine pressure regulator

presented in your SAR, the main steamline isolation valves are i' assumed to start closing (initiating a reactor scram) when the low steamline pressure is reached.

(a) Identify other transients that assume MSIV closure and reactor scram are initiated by the low steamline pressure signal.

(b) Provide a reanalysis of the failure of the turbine pressure regulator transient, and the other transients identified in (a), assuming MSIV closure and reactor scram at the proposed setpoint of 825 psig.

3. Were MCPR values of 1.38 and 1.29 for 8x8 and 7x7 fuel used as the initial thermal conditions for establishing the worst case for rod withdrawal error. If so, what is the rod block setting

and do the affected fuel bundles stay above a MCPR value of 1.06.

l

4. Provide the scram reactivity cu ve for E005.

i l