Text

Safety Evaluation Supporting Amend 36 to License NPF-86
	ML20082H955
Person / Time
Site:	Seabrook
Issue date:	04/10/1995
From:	; Office of Nuclear Reactor Regulation
To:	;
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ML20082H953	List: ML20082H949; ML20082H955;
References
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k UNITED STATES' "Ep-R I

NUCLEAR' REGULATORY COMMISSION.

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WASHINGTON, D.C. 2066 % 001 1

A SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION:

RELATED TO AMENDMENT NO.'36 TO FACILITY OPERATING LICENSE NO. NPF-86'

. NORTH ATLANTIC ENERGY SERVICE CORPORATION.

SEABROOK STATION. UNIT'NO. I-DOCKET NO. 50-443.

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1.0 INTRODUCTION

3 By application dated April 23,1993, (Ref.1) North Atlantic Energy Service

' Corporation (North Atlantic) proposed an amendment to the Appendix A Technical

. Specifications (TS) for the Seabrook Station, Unit No.1 (Seabrook). -The -

proposed changes would increase surveillance test intervals (STIs) and allowed 1

outage times'(A0Ts) for the reactor protection system (RPS) and engineered; safety. features actuation system (ESFAS). instrumentation, and would delete the requirementito perform the RPS Analog Channel Operational TestL(ACOT) on a staggered basis.

The proposed changes would minimize the potential for inadvertent ESFAS actuation and reactor trips-during surveillance testing, increase the.

operational effectiveness of plant personnel, and allow the resources that would be freed by the proposed changes;to be used for other tasks such as preventive' maintenance. Additionally, increased A0Ts would reduce the-potential for personnel error since more time would be allowed to perform test and maintenance actions.

2.0 BACKGROUND

In the early 1980s, oower reactor licenseesand the NRC focused 'upon the issue of the effects of surveillance testing and maintenance requirements upon plant operation.

Efforts were instituted to identify the scope and nature of surveillance testing and to develop alternative approaches that would provide better assurance that surveillance testing did not impact safety adverselyn A number of inadvertent reactor trips had occurred that' were attributed to human -

. error during performance of these activities. Human errors were found to be.

directly proportional Lto the frequency of surveillance -testing. Thus, more frequent surveillance' tests and shorter A0Ts were partly responsible for inadvertent-trips;and challenges to safet." systems.

To~ resolve the above concerns, the Westinghouse Owners Group (WOG) initiated'a L

l program to-evaluate.the effect of such undesirable events, and WOG. proposed TS changes to: increase STIs and' A0Ts.to' minimize the potential for inadvertent trips and challenges to the' safety systems while maintaining the benefits of

routine tests and maintenance activities to ensure the reliability of'the reactor trip. system (RTS) and ESFAS instruments.

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.3.0 EVALUATION j

l The WOG published results of its study and proposed actions in 1983 in WCAP-10271 (Ref. 2). This document was later revised several times in response to NRC staff comments (Ref. 3 - 5).

The staff reviewed all versions of WCAP-10271 including the WOG's responses to staff's questions on these submittals.

1 The NRC staff engaged the services of Brookhaven National Laboratory (BNL) to evaluate the approach used and the analyses performed in the WOG reports.

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determined the adequacy of W0G's methodology to establish technical bases for unavailability data, reliability calculations, and proposed STI/A0T extensions.

Following completion of the NRC staff and BNL staff reviews of the submittals, the NRC issued three safety ~ evaluations (Ref. 6 - 8). These safety-evaluations approved various TS changes relating to extending STIs, test / maintenance A0Ts, and bypass time for instrument channels in RTS, ESFAS, and the logic cabinets for these systems.

In the safety evaluations, the NRC staff approved extensions to STIs/A0Ts as well as to the time during which the instrument channels could be bypassed. However, the staff stipulated certain conditions that licensees must meet to include these pre-approved changes in j

plant-specific TS. The pre-approved changes and associated conditions are i

addressed below.

3.1 Pre-Approved Changes The NRC staff stipulated certain conditions to be met before the approved TS changes to RTS and ESFAS and to the logic cabinets of these systems could be made in any plant-specific TS. The pre-approved TS changes are described below and the associated conditions are described in Section 3.2 of this evaluation.

3.1.1 SE issued on February 21, 1985 (Reference 6)

In this SE the staff approved the following TS changes relating to RTS instruments only:

4 (1) The STI for RTS analog channel operational testing may be increased from monthly to quarterly.

(2) The duration for which an inoperable RTS analog channel may be maintained in an untripped condition may be increased from I hour to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

(3) The duration for which an inoperable RTS channel may be bypassed to allow testing of another channel in the same function may be increased from 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . Also, the channel test may be done in the bypass mode, leaving the inoperable channel in a tripped' condition.

(4) Testing of RTS. analog channels in a bypassed condition instead of a tripped condition will be allowed.

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' 3.1.2 SE issued on February 22,'1989 (Reference 7)

In this SE, the staff approved the following TS changes relating to ESFAS instruments:

(1) The STIs for the analog channels may be increased from monthly,to quarterly.

(2) The A0Ts for testing of analog channels may be increased from 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for both relays and solid state systems.

(3)

In solid state systems, the A0Ts for testing all components may be up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

(4)

In relay systems, the A0T for testing of the logic trains and master relays could be increased to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months and for the slave relays to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

j (5) The A0Ts for maintenance on all components may be extended to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for both relay and solid state systems. All components except the analog channels could be in the

. bypass mode during maintenance A0T, with an analog channel tripped after spending 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months in the bypass mode.

(6) Staggered testing is not required for analog channels in the ESFAS, and this requirement may be removed for analog channels.in RTS.

3.1.3 Supplemental SE issued on April 30, 1990 (Reference 8)

The staff's approval of the proposed STI/A0T extensions for the logic cabinets and reactor trip breakers for the RTS system was based on its evaluation of Appendix 0 to the WCAP-10271, Supplement 2, Revision 1 (Ref. 5).

The RTS and 1

ESFAS share some common instrumentation. Therefore it was necessary to 1

consider STI/A0T extensions for RPS logic cabinets. The staff's conclusions follow:

(1) The A0T extensions for the RPS logic cabinets as presented in Appendix 0 of Reference 5 are acceptable. These are 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for testing and 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for maintenance vice 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , respectively.

(2) The STI/A0T extensions for ESFAS functions associated with the Safety Injection, Steam Line Isolation, Main Feedwater Isolation, and Auxiliary Feedwater Pump Start Signals are acceptable.

(3) The STI/A0T extensions proposed in Appendix D of Reference 5 are not acceptable for reactor trip breakers.

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3.2 Associated Conditions for Approval 3.2.1 For the RTS changes

' Specific conditions on the staff's approval for the RTS changes,;as stated.in the SER (Reference 6) are (1) Performance of testing shall be done on a staggered basis. This condition was later removed by the ESFAS SER (Ref. 7).

8 (2) Procedures should be implemented to evaluate test-failures for common cause, and additional testing should be performed if necessary.

(3) Approval of channel testing, Items 3.1.1 (3) and (4) above, in a bypassed condition assumes that the plant design allows such testing without lifting any leads or installing temporary jumpers.

i (4) The approved revisions to the TS as described above in Items 3.1.1 j

(1) through (4), also apply to the reactor coolant pump undervoltage and underfrequency functional units.

(5) For RTS channels which provide dual inputs to other safety related systems such as ESFAS, the approval of Items 3.1.1 (1) through (4) above applies only to RTS functions.

1 (6) An increased STI would change the margin for the analog channel setpoint; therefore, an approval of increased STI is contingent on confirmation by the licensee that their setpoint methodology includes sufficient margin to offset the drift anticipated as a result of less frequent surveillance.

3.2.2 For the ESFAS changes Specific conditions on the staff's approval for the ESFAS changes, as stated in the SSE (Ref. 8):

(1) Acceptance of item 3.1.3 (1) is contingent on including a separate action statement for modes 1 and 2 for RPS Automatic Trip and Interlock Logic Functional Units'. The model Action Statement given below is in the format of Westinghouse Standard Technical Specifications, Revision 4, Table 3.3-1 (Ref. 9).

ACTION 12 - With the number of OPERABLE Channels (analog 4

channels and trip logic) one less than the Minimum Channels OPERABLE requirement, restore the inoperable channel to OPERABLE status within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ; however, one channel may be bypassed for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for surveillance testing per Specification 4.3.1.1, provided the other 4

channel is OPERABLE.

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(2) The licensee must confirm the applicability of the generic analyses to the plant.

-(3) The licensee must confirm that any increase in instrumant drift due to the extended STIs is properly accounted for in the setpoint calculation methodology.

4.0 EVALUATION OF PROPOSED REVISIONS l

The staff has evaluated North Atlantic's proposed changes.to the Seabrook TS to verify that they are consistent with the pre-approved changes and that North Atlantic has met all the conditions associated with those changes.

4.1 Verification that proposed changes are consistent with the pre-approved changes 4.1.1 TS 3.3.1, Table 3.3-1 (1)

Functional Units 11,12a,12b, and 16a Procosed Chanae:

Replace ACTION 7 with ACTION 6.

Evaluation: For Functional Units 11 (Pressurizer Water Level--High),

12.a (Reactor Coolant Flow--Low, Single Loop (Above P-8)),12.b (Reactor Coolant Flow--Low, Two Loops (Above P-7 and,below P-8)), and 16a (Turbine Trip, Low Fluid Oil Pressure), with the total number of operable channels requirement not met, ACTION 7 allows continued operation until the next analog channel operability test provided the inoperable channel is tripped within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

ACTION 6 allows continued operations prov.ided (a) the inoperable channel. is tripped within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and (b) the minimum channel operable requirement is met. ACTION 6 allows bypassing the inoperable channel for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for surveillance testing.

The above_ change is acceptable because it is consistent with pre-approved changes as described in Sections 3.1.1 (2) and 3.1.1 (3) of this evaluation.

(2) Functional Units 17 and 20 Pronosed Chanae:

Replace ACTION 9 with a new ACTION 7.

Evaluation:

For Functional Units 17 (Safety Injection Input From ESF) and 20 (Automatic Trip and Interlock Logic), with the minimum channel operable requirement not met, ACTION 9 requires plant shutdown to at least HOT STANDBY within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and allows one channel to be bypassed for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance test testing.

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p 6-i The new ACTION 7_ would allow 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months to restore the' inoperable channel-before requiring shutdown to HOT STAND 6Y within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and would allow bypassing one channel for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for surveillance -

testing.-

The above change is acceptable because~ it11s consistent'with pre-approved changes as described in Sections 3.1.1 (2), 3.1.1 (3), and 3.2.2 (1) of this' evaluation.

(3) Functional Units 9,10, -and 13 i

Pronosed Chanae: Delete Table Notation (1)- and references to Table Notation (1) for Functional Units 9,10, and 13.

j Evaluation: Table Notation (1) states: "These channels also provide inputs to ESFAS. Comply with the applicable MODES and surveillance frequencies of Specification 3.3.2 for any portion of the channel required to be operable by Specification 3.3.2."

The Table Notation was required because the ESFAS A0Ts were more restrictive than the RPS-A0Ts..The Table Notation is no longer. required because the A0T for the RTS and ESFAS functions are proposed to be the same.- Deleting Table Notation (1) and references to Table Notation (1) for Functional Units 9, 10, and 13 is acceptable to the staff.

4.1.2 TS 4.3.1.1, Table 4.3-1 (1) ' Functional Units 2a through 4 and 6.through 15 Pronosed Changg: Delete Note 16 and references to Note 16 for Functional Units 2a through 4 and 6 through 15.

' j Evaluation: The proposed revision removes the requirement to test th'e following channels on a staggered test basis:

o Power Range, Neutron Flux High Setpoint, o Power Range Neutron Flux, High Positive Rate, o Power Range, Neutron Flux, High Negative Rate,

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o Source Range, Neutron Flux o Overtemperature A T, o Overpower A T, o Pressurizer Pressure -- Low, o Pressurizer Pressure -- High, o Pressurizer Water Level -- High, o Reactor Coolant Flow -- Low, o Steam Generator Water Level -- Low-low o Undervoltage - Reactor Coolant Pumps, and 4

o Underfrequency - Reactor Coolant Pumps The above change is acceptable because it is consistent with the pre-approved changes described in Section 3.1.2 (6) of this evaluation.

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-(2) Functional Units 9, 10, and 13 Proposed Chanae: Delete Note 17 and references to Note 17 for-i Functional Units 9, 10, and'13.

Evaluation: Note'17. states: "These channels also provide inputs.

to ESFAS. Comply with the applicable MODES and surveillance frequencies of. Specification' 4.3.2.1. for any portion.of the channel-required to be operable by Specification 3.3.2."

Note 17 was required because the ESFAS A0Ts were more restrictive i

than the RPS A0Ts. Note 17 is no longer required because the-A0T.for the RTS and ESFAS functions are' proposed to be the same.

Deleting Note 17 is acceptable to the staff.

4.1.3 TS 3.3.2, Table 3.3-3 (1) Functional Units 1.c,1.e, 4.c, 4.d, and 4.e Proposed Chanae: Replace existing ACTION 14 with revised ACTION 18 for-Functional Units 1.c, 1.e, 4.c, 4.d, and 4.e.

Evaluation:

For Functional. Units Ic.(Containment Pressure--Hi-1), le (Steam Line Pressure--Low), 4c-(Containment Pressure--Hi-2), 4d (Steam Line Pressure-Low), and 4e (Steam Generator Pressure-Negative Rate i

High), with the total number of operable channels requirement not met, the existing ACTION 14 allows operations to proceed until performance of the next required analog channel operational test, provided the inoperable channel is tripped within I hour.

The. revised ACTION 18 would allow continued operations if'(a) the inoperable channel.is tripped within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and (b) the requirement for the minimum operable channels is met. ACTION 18 would' allow the inoperable channel 'to be. bypassed for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for surveillance testing.

Thus, the time for putting the inoperable channel in the tripped condition is extended.from I hour to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and the inoperable channel is allowed to be bypassed for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months while the other channels are being tested, y

The above change is acceptable because it is consistent with the pre-i approved change as' described in Section 3.1.2 (5) of this evaluation.'

i (2) Functional' Units 9.a and 9.b Proposed Chanae: Replace existing ACTION 18 with new ACTION 14.

Evaluation: For ESFAS Functional Units 9.a -(start of emergency feedwater on emergency bus loss of voltage) and 9.b (start of emergency 1

feedwater on emergency bus degraded volta 93 coincident with safety 1

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_ _8-t injection), with the total' operable channel requirement not met, the existing ACTION 18 allows continued operation if (a) the inoperable channel is tripped within'l hour and (b) the minimum operable channel requirement is met. Action 18 allows bypassing one additional channel.

for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing.

t The new ACT. ION 14 is similar to the existing ACTION 18, but extends the-time allowed for tripping.the inoperable channel from 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and allows bypassing the inoperable channel for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing.

1 The'above change.is acceptable because it is consistent with the pre--

1 approved change as described in Section 3.1.2 of this evaluation.

(3) ACTIONS 13, 20 and 22-Pronosed Chance: Revise ACTIONS 13, 20, and 22 to a110w.6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months to restore an inoperable channel to operable status before. requiring shutdown to HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and increase the

. allowed time for bypassing a channel for surveillance testing from 2 to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

Evaluation: With the number of OPERABLE channels one less than the allowed minimum operable channels, the' existing ACTIONS 13, 20, and 22 require the plant to be in HOT STANDBY within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and allow one channel to be bypassed for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing provided the other channel is operable.

The revised ACTIONS 13, 20, and 22 would require the plant to be l

shutdown to HOT STANDBY within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , and would allow bypassing one channel for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for surveillance testing. ACTIONS 20 and 22 also would require the inoperable channel to be restored within the d

first 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

The above changes are acceptable because they are consistent with the pre-approved changes as described in Section 3.1.2 of this evaluation.

1 (4) ACTION 14 i

Pronosed Chanae: Replace existing ACTION 14 with a new ACTION 14.

i Evaluation: The existing ACTION 14 requires tripping an inoperable channel within I hour and allows continued operation until the next-analog channel operational test.

The new ACTION.14 allows continued startup and power operations provided (a) the inoperable channel is placed in the tripped condition within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and (b) the minimum channel requirement is met. The new ACTION 18 allows bypassing the inoperable channel for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing of the other channels.

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This change is acceptable because it is consistent with the pre--

approved. changes as-described in 3.1.2 (5) of this evaluation.

k (5) ACTION <15'.

Proposed Chance:.-Revise ACTION'15 to increase the time a second containment pressure High-3 channel may be bypassed to allow testing of.

the. channel'from 2 to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

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Evaluation:- With the numb' r of OPERA 8LE channels one less' than the

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proceed provided the inoperable channel is placed in the bypassed condition and the requirement for the minimum channels operable is met.

One additional channel may be bypassed for'up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for-surveillance testing per Specification 4.3.2.1., The revised ACTION 15 allows the second channel to be bypassed for.up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months for surveillance testing.

.j The above change 'is acceptable because it is consistent with the pre-approved changes described in 3.1.2 of this evaluation.

(6) ACTION.18 Proposed Chanae: Revise ACTION 18 to increase the time an'. inoperable channel may be maintained in an untripped condition from 1 to 6' hours.

Revise ACTION 18 to-increase the~ time an inoperable channel may be bypassed to allow surveillance testing of other channels in the same 1

function from 2 to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

For ACTION 18, change "one additional" to "the inoperable."

Evaluation: With the number of operable channels one.less than the total number of channels, the existing ACTION 18 allows.-startup and/or i

power operation-to proceed provided (a) the inoperable channel is-placed in the tripped condition within I hour and (b) the requirement for the minimum channels operable is met. The existing ACTION 18 i

allows one additional channel to be bypassed for up.to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for' surveillance testing.

1 The revised ACTION 18 requires the inoperable channel to be tripped-.

I within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and allows bypassing the inoperable channel for up to 4 -

hours for surveillance. testing.

y This change is acceptable because it is consistent with the pre-i approved changes described in Section 3.1.2 of this evaluation.

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' 4. I '. 4 TS 4.3.2.1, Table 4.3-2 pronosed Chanae: Revise the analog channel operational test (ACOT) entries to increase' the STI from monthly to quarterly for. Functional-Units 1.c, l.d, 1.e, 2.c, 3.b.3, 4.c,.4.d, 4.e, 5.b, 6.a 6.b, 7.c, 8.b, 10.a, and 10.c.

Evaluation:

STI for these ESF instruments per existing TS Table 4.3-2 requirement is monthly. The revision to the Table 4.3-2 changes the STI.

- for these instruments from monthly to quarterly.

-The above change is acceptable because it is consistent with the pre-approved changes described in Section 3.1.2 (1) of.this evaluation.

4.2 Verification of Conditions North Atlantic has confirmed that it has met the SE conditions as described below.

(1) Condition 3.2.1 (1)

Performance of testing on a staggered basis was stipulated by the RTS SE (Ref. 6), but was removed later by the ESFAS SE (Ref. 7).

Therefore, North Atlantic has proposed to remove this condition from the plant's TS.

This is acceptable.

(2) Condition 3.2.1 (2)

North Atlantic has stated that a procedure to evaluate surveillance test failures of the RTS channels for common mode failures and to provide for additional testing when necessary will be in place at Seabrook Station, Unit 1, prior to implementing the changes proposed. This is acceptable.

(3) Condition 3.2.1 (3)

The Seabrook design does not have installed bypass-testing capability for the analog instrumentation associated with the RTS or ESFAS with the exception of the Containment High-3 channels. - North Atlantic has stated that any future bypass testing will be accomplished without reliance upon lifting of leads or installation of temporary jumpers.

Plant modifications will be required if North.

Atlantic elects to test channels in t,ypass other than the Containment High-3 channels. The staff agrees that testing in bypass is acceptable once design modifications are made that avoids the lifting of leads and/or the installation of jumpers.

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' '(4) ~ Condition 3.2.2 (2)

The generic analyses used in WCAP-10271 and its supplements are applicable to Seabrook Station, Unit 1.

The Seabrook design incorporates the Westinghouse Process Control System and the.

,1 Westinghouse Solid State Protection System for both ESFAS and RTS.

These systems were specifically modeled.in the generic analyses.

-l This is. acceptable.

H The'Seabrook RPS and ESFAS Functional: Units influenced by the proposed changes are addressed by the generic analyser, and the proposed changes are consistent with the pre-approved TS changes with two exceptions..The exceptions are-(1) Functional Unit 6.b,-

(Feedwater Isolation on Low RCS Tavg Coincident with Reactor Trip) and (2) Functional Unit 8.b, (Automatic Switch'over to the.

Containment Sump).

North Atlantic has performed specific qualitative evaluations to justify the proposed changes associated with the feedwater isolation and automatic switchover to the containment' sump. The evaluations.

.l demonstrate that any increase in the unavailability of these t

functional units due to change in STI and. A0T for the RCS Tavg Low'

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and RWST Level Low-Low signals is acceptable since the unavailability of these functions is dominated by the previously reviewed and approved Safety Injection signal unavailability.

Additiondly, the Feedwater Isolation on Low RCS Tavg Coincident with Reactor Trip function is not credited in any safety analysis for Seabrook.

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(5) Condition 3.2.2 (3)

North Atlantic has reviewed Seabrook RTS and ESFAS instrument calibration and operational surveillance records for a 2 year period. The review followed the staff guidelines provided in a-letter from C. E. Rossi to R. F. Janecek (BWR Owners Group), dated April 27, 1988. North Atlantic asserts that this review confirmed that instrument drift assumptions in setpoint calculations remain valid when the STI is changed from 1 to 3 months. North Atlantic has committed to review future calibrations for excessive drift as j

part of the procedure discussed in Section'4.2.2. ~ This is

.I acceptable to the staff.

1 5.0 SUPMARY :

The staff reviewed North Atlantic's evaluation of the proposed changes and agrees with its conclusions that:

.(a)- Although the proposed changes would cause an increase in the unavailability of the ESFAS and RTS, the resultant increase in the core damage frequency (CDF) is.very low.

Further, the changes are justified in light of the reduction in the potential for inadvertent tripping of ESFAS or RTS functions which may result in inadvertent trips.

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e 12-(b) The proposed changes will not result in physical alteration to any plant system or in plant operating procedures. Therefore,'there can be no impact on plant response to the point where-a different accident is created.

(c) The proposed changes do not alter'the manner in which the safety limits, limiting safety system setpoints and limiting conditions for operation e

are determined. The impact of reduced testing is to allow a longer time interval over which instrument uncertainties such as drift or failure rates may act. However, North Atlantic's commitment to monitor and address increases in uncertainty due to drift resolved this concern.

The staff believes that implementation of the proposed TS changes would result in following benefits which will result in an improvement in safety.

1.

Reduced testing will result in fewer inadvertent reactor trips,_less frequent actuation of ESFAS components, and less frequent distraction of operations personnel.

2.

Improvements in the effectiveness of the operating staff in monitoring and controlling plant operation will be realized. This is due to less frequent distraction of the operators and shift supervisor when attending to instrumentation testing.

3.

Longer repair times associated with increased A0Ts would lead to higher quality repairs and, therefore, would improve reliability.

6.0 STATE CONSULTATION

In accordance with the Commission's regulations, the State of New Hampshire and Commonwealth of Massachusetts officials were notified of the proposed issuance of the amendment. The State officials had no comments.

7.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR_

Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves 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 the amendment involves no significant hazards consideration, and there has been no public comment on such finding (58 FR 41507). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9.

Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

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1

8.0 CONCLUSION

The Commission has concluded,. based on the considerations discussed above,

- that:- (1) there is reasonable assurance that the health and safety of the

'i public will not be endangered by operation in the proposed manner, (2):such activities.will be conducted in compliance with the commission's regulations, 1

and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

6.0 REFERENCES

r.

1.

Feigenbaum, T. C., letter to NRC, January 13,1993, submitting License Amendment Request 93-04: Engineered Safety Actuation System Surveillance i

Intervals, North Atlantic Energy Service Corporation, NYN-930007.

j 2.

Sheppard, J.

J., letter to H. R.'Denton, February 3, 1983, submitting WCAP-10271, " Evaluation of Surveillance Frequencies and Out of Service 4

Times for the Reactor Protection Instrumentation System".

3.

Sheppard, J.

J., letter to C. Thomas, October 4, 1983, submitting WCAP-10271, Supplement 1.

4.

Butterfield, L., letter to H. R. Denton, March 20, 1986, submitting i

WCAP-10271, Supplement 2, " Evaluation of Surveillance Frequencies and Out of Service Times for the Engineered Safety Features Actuation System",

February 1986.

5.

Newton, R. A., to R. Starosticki, May 12, 1987, submitting WCAP-10271, Supplement 2, Revision 1, " Evaluation of Surveillance Frequencies and Out i

of Service Times for the Engineered Safety Features Actuation System",

March 1987.

6.

Thomas, C.

0., letter to J. J. Sheppard, February 21, 1985,

Subject:

Acceptance for Referencing of Licensing Topical Report WCAP-10271,

" Evaluation of Surveillance Frequencies and Out of Service Times for the Reactor Protection Instrumentation System".

7.

Rossi, C. E., letter to R. Newton, February 22, 1989,

Subject:

Westinghouse Topical Reports WCAP-10271, Supplement 2, and WCAP-10271, Supplement 2, Revision 1, " Evaluation of Surveillance Frequencies and Out of Service Times for the Engineered Safety Features Actuation System".

8.

Rossi, C. E., letter to G. T. Goering, April 30, 1990,

Subject:

Westinghouse Topical Reports WCAP-10271, Supplement 2, Revision 1,

" Evaluation of Surveillance Frequencies and Out of Service Times for the l

Engineered Safety features Actuation System".

4

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_ 14 _

i 9.

NUREG-0452, Westinghouse Standard Technical Specifications, Revision'4, Fall 1981..

]

Principal Contributor: Albert De Agazlo Date:-

April 10, 1995

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ML20082H955

Contents

Text

1.0 INTRODUCTION

2.0 BACKGROUND

6.0 STATE CONSULTATION

7.0 ENVIRONMENTAL CONSIDERATION

8.0 CONCLUSION

6.0 REFERENCES

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ML20082H955

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1.0 INTRODUCTION

2.0 BACKGROUND

6.0 STATE CONSULTATION

7.0 ENVIRONMENTAL CONSIDERATION

8.0 CONCLUSION

6.0 REFERENCES

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