ML19325D741

Forwards Application for Amends 126 & 77 to Licenses NPF-14 & NPF-22,respectively,requesting Emergency Temporary Relief from Certain Requirements of Tech Specs 3.2.2 on One Time Basis for Period of 3 Months

ML19325D741
Person / Time
Site:	Susquehanna
Issue date:	10/19/1989
From:	Keiser H PENNSYLVANIA POWER & LIGHT CO.
To:	Butler W Office of Nuclear Reactor Regulation
Shared Package
ML19325D742	List: ML19325D741 ML19325D745 ML19325D749
References
PLA-3279, NUDOCS 8910260052
Download: ML19325D741 (5)

Text

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ppd Mnsyivania Power & Light Comphny .

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' Two North Ninth Stroot.

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, ' f Harold W. Keiser .

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> , 'i s" ,+. l October 19-, 1989, " '

a4 x' Director of Nuclear. Reactor; Regulation- ,

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. Attention Dr. W.,R. Butler, Project Director. ' '

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Project DirectorateLI-2. >i

Division ~of Reactor: Projects 4 'sU._S.' Nuclear Regulatory Commission

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E. SUSQUEHANNA STEAM. ELECTRIC STATION' l}

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' PROPOSED AMENDMENT:NO.c126 TO NPF-14 ..

< .AND' PROPOSED AMENDMENT NO. 77;TO NPF-22 '

(EMERGENCY CHANGES) .

, , Docket Nos.'50-387 ,

, ,PLA-3279 ' FILES R41-2. A17 and 50-388 [;

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Dear.Dr.. Butler:

This'ietter is an emergency request for NRC approval of temporary

-relief: Lfrom the ~ provisions of the. Susquehanna Technical ,

! Specifications for Units .l' and 2. The requested changes, attached i

in . ' marked-up : form, propose that certain requirements' of

Specification 3.2.2 be eliminated on a.one time basis for a period of threatmonths. '

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y i BACKGROUND l: . . -b

. Differential temperature sensing systems are installed in the RCIC l

'and RWCU equipment rooms, the HPCI/RCIC piping area, and in the j main steam tunnel. These systems are designed to measure inlet and  ;

exhaust differential temperatures and initiate an isolation' signal p' iat a' predetermined differential temperature..

vn h s LIn:the course of determining steam leak time temperature profiles l 1 . . for; the RCIC room, room pressure transient studies were also y , f" performed. This was done to determine whether interaction existed  :

between- the differential temperature circuits and the backdraft  ;

' isolation' dampers (BDID) HVAC isolation function. These BDID's

. isolate the RCIC room upon sensing a high differential pressure '

l between the RCIC room and atmospheric pressure. It was found that ,

DDID operation (HVAC Isolation) would render the differential I

. temperature sensing instrumentation inoperable. A similar l

{ configuration was alt.o found to exist in the RWCU equipment room, J the main steam tunnel and in the HPCI/RCIC piping area. l s

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891b260052 891019  ? .

N PDR ADOCK 05000387 m

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l FILES R41-2, A17-2 PLA-3279 l Dr. W. R. Butler- j i

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The' differential temperature sensing' systems are included in the technical specification. Therefore, the configuration described C above requires the sensing systems to be declared inoperable which -

- in turn would result in a dual unit shutdown.

JUSTIFICATIOM FOR THE CHANGE Susquehanna has other diverse and redundant methods for detecting, alarming, and automatically isolating steam leaks. For example, in' the RCIC system, in addition to differential temperature  ;

instrumentation, ' safety- related instruments cause automatic ,

isolation of the RCIC system for the following abnormal conditions:

o High RCIC room ambient temperature o'High RCIC room cooler inlet temperature

• o High RCIC steam flow o Low RCIC steam supply pressure o High RCIC steam turbine exhaust vent pressure In addition to the above cutomatic isolation functions, the following other instruments provide operators with alarms which are indications of a reactor coolant pressure boundary leak in the RCIC room:

o RCIC room high ambient temperature o RCIC room cooler high inlet temperature o RCIC room high radiation o RCIC room flood detection Also, the fast closure of the BDID's which will be annunciated in the main control room through a system trouble alarm, can be considered another diverse method of warning operators of a steam leak.

The other systems affected by this change have similar levels of diverse and redundant methods for detecting, alarming, and automatically isolating steam leaks.

Also, the associated alarm response procedures will include direction to the operator that upon receipt of an alarm there is potential that the alarm was caused by a steam leak.

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MO SIGNIFICAMT EhEARDS EVALUATION ,

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The proposed changes do not

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i I. Involve a significant increase in -the probability or consequences of:an accident previously evaluated.

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Susquehanna -is provided with many diverse and redundant methods of detecting, alarming, and automatically isolating systems which . interface with the reactor coolant pressure ,

L boundary when a leak is detected in one of these systems. The 1 l systems being discussed herein are RCIC, Reactor Water Cleanup ,

. (RWCU)', HPCI and the Main' Steam Line.

Redundancy in automatic isolation for relatively small lea'ks in the reactor coolant pressure boundary-is provided in each i case by multiple high room ambient temperature sensors. RCIC is also provided with automatic isolation for area cooler L inlet high temperature and HPCI/RCIC piping area high '

L temperature.- 'Other types of signals which cause automatic L system isolations for the larger break accident scenario L4 include high steamline flow, low steam inlet pressure, and high turbine exhaust diaphragm pressure for HPCI and RCIC; high differential flow, high flow, and low reactor water level for RWCU; high flow and low reactor water level for RHR; and L low reactor water level, high main steam line radiation, low -

main steam line pressure, high main steam line flow, and low  !

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[ condenser vacuum for the main steam line. l In addition to the automatic isolations mentioned above, other I; instruments provide operators with alarms which are  ;

L indications of a reactor coolant pressure boundary leak in l these rooms. Pre-isolation alarms are provided for high room

( ambient and high area cooler inlet temperature where applicable. Other types of alarms which alert operators to an abnormal condition related to a steam leak in a particular L room include high area radiation, room flood detection, room fire detection and backdraft isolation damper closure.

There are diverse and redundant methods available for ,

detection, alarming, and automatic isolation of a reactor coolant pressure boundary leak in secondary containment.

Elimination of difft 'antial temperature monitoring does not in any way significantly reduce this capability.

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FILES R41-2, A17-2 PIA-3279 ' )

Dr. W. R. Butler 1

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i m II. Create the' possibility of a new or different' kind of accident' ~

from any previously evaluated.

Based' on the analysis presented in Item I above, the elimination of differential temperature. monitoring does not significantly affect the ability to detect and isolate leaks in secondary containment. Therefore the proposed action does not ' create a possibility for a new or different' type of ,

accident from any previously evaluated.

III.^ Involve a significant reduction in the margin of safety.

The' proposed action, while reducing the number.of specific loops acting to isolate a leak as measured by a thermal L condition, : does not measurably change the probability of }

successful leak detection of that condition and isolation of the leak. Therefore the margin'of safety is not reduced. ,

BASIS FOR EMERGENCY CHANGE >

10CFR50.91 provides guidance on the information required to support an application for an emergency change.

l' First, it requires the applicant to justify that an emergency L

exists i.e., " ... failure to act in a timely way would result in derating or shutdown of a nuclear unit... " . Under the current l ", configuration the differential temperature sensing systems for the ,

RCIC- and RWCU equipment rooms, the main steam tunnel, and the HPCI/RCIC piping area would have to be declared inoperable and the actions of Technical Specification 3.2.2 invoked. This would '

require each affected system to be isolated and in the case of the u main. steam line this results in shutdown of the units. This meets lL the specified criteria.

i .. Second, 10CFR50.91 requires a licensee to "... explain why this Lu emergency situation occurred and why it could not avoid the L situation... " . The discovery of this design was a result of an I

extensive PP&L efforts to analyze the steam leak detection and isolation system changes. This conflict was not caused by any plant modification but rather was inherent in the original design.

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5- FILES R41-2, A17-2 PLA-3279 l 9 Dr. W..R. Butler I

'As soon as it became clear that this request was the only plausible - ]

way to avoid'a shutdown, the appropriate internal processes were j implemented in support of this submittal application. 1 1'

As noted previously,'PP&L requests this change-be effective as~of October 19, 1989, and remain in effect for a period not to exceed

) ninety (90) days..

Any questions regarding .this. submittal should be directed to Mr. C. T. Coddington at-(215) 770-7915.

Very truly yours, LLC &da, l

H. W. Keiser Attachments

i. cc: NRC2 Document 3 Control; Desk;;(original)1G .l

! NRC Region I L Mr. M. C. Thadani, NRC Project Manager-Rockville  :

Mr. G. S. Barber, NRC Sr. Resident Inspector-SSES l Mr. T. M. Gerusky, Pennsylvania DER t i-t l

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