ML17156A269

Safety Evaluation Supporting Amends 44 & 11 to Licenses NPF-14 & NPF-22,respectively

ML17156A269
Person / Time
Site:	Susquehanna
Issue date:	05/15/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML17156A268	List: ML17156A267 ML17156A269
References
NUDOCS 8505280522
Download: ML17156A269 (6)

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v'I%*4 UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION AHENDNENT NOS.

4 AND TO NPF-14 AND NPF-22 SUS UEHANNA STEAIP ELECTR:C STATION, UNITS 152 DOCKET NO. 50-387/388 Introduction By letter dated January 31, 1985, from N. R. Curtis to A. Schwencer,'s supplemented by letter dated Nay 3, 1985, the Pennsylvania Power and Light Company (the licensee) requested changes to the Technical Specifications for

,Susquehanna Steam Electric Station, Units 1 and 2.

The proposed changes are made in conjunction wiih a modificatiorI to the actuation logic for the Automatic Depressurization System (ADS).

The change'o the, ADS logic adds a

timer which bypasses the high drywell pressure permissive after a sustained low water level indication, and adds a manually operated inhibit switch.

These design changes were generically approved by the staff'n memorandum

,"from R.

W. Houston to G. Lainas, "Evaluation o

BLAIR Owner's Group Generic

Response

to Iten II.V.3.18 of NUREG-0737 'Modification of Automatic Depressurizatinn System Logic,'dated April 1, 1983.

Evaluation mo'DPJR mOQ IAO OO IOID NO

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CQO IDn OR IN Ol IDOK IDR mo CLI The Automatic Depressurization System (ADS) has been modified in accordance with THI Action Plan-II.K.3.18 to automatically initiate in the absence of a high drywell pressure initiation signal.

The ADS functions as a backup to the High Pressure Core Injection SystenI (HPCI) by depressurizing the reactor vessel so that low pressure systems may inject water for.core cooling.

The ADS is currently actuated upon coincident signals of reactor vessel low water level, high drywell pressure, a low pressure ECCS pump running, and a

105 second time delay which allows ADS to be bypassed if the operator believes the actuation signal is erroneous or if vessel water level can be restored; However, for iransient and accident events which do not produce high drywell pressure, and are further degraded by a loss of HPCI, manual actuation of the ADS would be required to ensure adequate core cooling.

To reduce the dependence for manual ADS actuation in order to ersure adequate core cooling, the applicant has installed bypass urIIers which will automatically bypass the drywell high pressure inputs required for ADS actuation if reactor vessel water level remains below the ADS initiation setpoint (level

1) for a sustained period (8 minutes}.

After the 8 minute time delay and the 105 seccno time delay, ACS will be automatically actuated in the absence of a drywell high pressure signal if a reactor vessel low water level condition still exists and a low pressure ECCS pump is running.

Four 8 minute time delays have been

added, orre for each ADS drywell high pressure initiation channel.

There are two ADS actuatior, chanrIels (Division 1

and Division 2}, either of which can perform'he required ADS function.

There are two bypass timers associated with each ADS division.

Both the 8 mirIui.e bypass timer and the 105 second actuation timer will reset if reactor water level recovers above the trip elevation before it times out.

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'nother modification made to the Susquehanna Steam Electric Station, Units 1

and 2 ADS consists of the addition of two ADS manual inhibit switches (one per ADS division) that permit the operator to override the ADS automatic blcwdown logic if necessary.

These manual inhibit switches are located on a control room pai el near, the controls for. the safety relief valves.

A keylockea switch is used for the hanual inhibit function to provide a means of lit>>iting the

'potential for inadvertent actuation of the marual inhibit.

Alarms alert the operator of tirie-out of the bypass timer and activatlbl Gf the manual inhibit switches.

le have reviewed the licensee's proposed technical specification changes ar d conclude, that the Technical Specification Changes are acceptable since they conform to the BWR Owner's Group generic response to Iter; '.I.K.3. 18 of HUREG-073" which was approved by the staff or April 1, 1983.

The licensee in their original submittal

proposea, an Action Statement 37, tn allow a division of ADS to be out-of-service for up to 14 days if the require-ment for minimum operable channels per trip system is not satisfied.

This was in lieu of the typical operating plant and standard technical specification action statement for ADS which places the inoperable channel in a tripped condition within one hour cr declares

.he associated ECCS inoperable.

1!ithout a detailed engineering assessment from the licensee regarding the origination and validity cf the 14 day out-of-service time, the staff is, unable to evaluate this particular action statement.

As a result on Hay 3, 1985 U e licensee withdrew their request to implement Action 37 but plans to resubmit another request in ihe near future.

The staff recognizes tha'he previously approved action statement 30 (for which Action 37 was proposed to replace) which places the trip system in a tripped condition if she requirement for minimum operable channels per trip system is not satisfied, is too restrictive.

The staff encourages the licensee to resubmit a proposed technical specification change pertaining to Action Statement 30 and to provide at that time a clear technical basis foi its support.

Therefore, the licensee is still required to utilize the previously approved action statements for the ADS actuation instrumentation.

In view of the withdrawal of proposed Action Statement 37, Action Statements 31 and 33 are applicable for the recently added trip functions, ADS drywell pressure bypass timer end manual inhibit, respectively.

In addition,. the staff concludes that the Susquehanna ADS design meets the requirements of Tlii Ac'tion Plan Item II.K.3.18 regarding ADS automatic actuation to ensure adequate core cooling, and, therefore, is acceptable.

Finally, this amendrient corrects errors contained in Table 3.3.3-1 Emergency Core Cooling System (ECCS) Actuation Logic Instrumentation (page 3/4 3-28) of the Unit 1 and 2 Technical Specification..

Footnote (a), where originally located or this page; applied to every entry.

Footnote (a) states:

"A Challnel may be placed in an operable status fo>

up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for required surveillance without placing the trip system in the tripped condition provided a+. least one OPERABLE channel in

@he same trip system is monitoring that parameter."

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P4 Egf This footnote was erroneously applied to the manual initiation functions, which can be performed without placing the required system in an inoperable

status, and the Level 8 high pressure coolant-injection trip function which would become unavailable if one channel were placed in an inoperable status.

The proposed amendment removes this footnote from these functions since it was incorrectly applied originally.

The staff concludes, therefore, that this change is acceptable.

Environmental Consideration These amendments involve changes in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.

The staff has determined that the. amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase

-in individual or cumulative occupational radiation exposure.

The Commission has previously issued a proposed finding that these amendments involve no significant hazards consi'deration and there has been no public comment on such finding.

Accordingly, these amendments meet the eligibili~y criteria for categorical exclusion set forth in CFR,31.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental mpact statement or environmental assessment need he prepared in connection with the issuance of these amendments.

Conclusion Me have concluded, based on the considerations discussed above, that:

(~) there is reasonable assurance that the health and safety of the public will

.not be endangered by operation in the proposed

manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

Dated:

ANY 15 $85

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