ML20198H838

Suppl 1 to Application for Amends 151 & 135 to Licenses NPF-10 & NPF-15,revising TS 3.5.2, ECCS-Operating, to Extend Allowed Outage Time from 72 H to 7 Days for Single Low Pressure Safety Injection Train

ML20198H838
Person / Time
Site:	San Onofre
Issue date:	01/09/1998
From:	Nunn D SOUTHERN CALIFORNIA EDISON CO.
To:
Shared Package
ML20198H826	List: ML20198H821 ML20198H838 ML20198H851
References
NUDOCS 9801130406
Download: ML20198H838 (12)

Text

a UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION Application of SOUTHERN CAllFORNIA' '

)

Docket No. 50-362 EDISON COMPANY, H R.

for a Class 103

)

License to Acquire, Possess, and Use a Utilization Facility as Part of Amendment Application Unit No. 3 of the San Onofre Nuclear No. 135, Supplement 1 Generating Station

)

SOUTHERN CAllFORNIA EDISON COMPANY, H E. pursuant to 10 CFR 50.90, hereby submit Amendment Application No. 135.

This amendment application consists of Proposed Change Number (PCN)-452, Supplement 1 to Facility Operating License No. NPF-15.

PCN-452 is a request 5*0f I to revise Unit 3 Technical Specification 3.5.2, "ECCS-Operating," to extend the allowed outage time from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for a single Low Pressure Safety injection train.

L Supplement I adds a new TS 5.5.2.14 " Configuration Risk Management Program."

The purpose of the Configuration RisL Management Program (CRMP) is to ensure that a proceduralized Probabilistic Risk Assessment-informed process is in place that assesses the overall impact of plant maintenance on plant risk.

Implementation of the CRMP will enable appropriate actions to be taken or

$m,1 decisions to be made to minimize and control risk when performing on-line maintenance for Systems, Structure:, and Components with a risk-informed Completion Time. TS 5.5.2.14 will be applicable to TS 3.5.2 because the Completion Time for TS 3.5.2 is a " risk-informed Completion Time."

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98011"J0406 980109 DR ADOCK 0500 1

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Subscribed on this

' day of b M L M U

,1998 Respectfully submitted, SOUTHERN CAllFORNIA EDISON COMPANY.

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A Dwight Nun Vice Presid it s

State of California nj fore me,'1 M C. f)O l'1 ldM,

personally appeared

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A. to A A J, personally known to

- me to be the person whose n1the is subsc'ibed ~to the ilthin instrument and r

acknowledged to me that he executed the same in his authorized capacity, and thah b his signature on the instrument the person, or the entity upon behalf oh ich the person acted, executed the instrument.

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of UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION Application of SOUTHERN CAllFORNIA.

)

Docket No. 50-361 EDISON COMPANY, H E.

for a Class 103

)

License to Acquire, Possess, and Use

)

a Utilization facility as Part of

)

Amendment Application Unit No. 2 of the San Onofre Nuclear

)

No. 151, Supplement 1-Generating Station

)

SOUTHERN CALIFORNIA EDISON COMPANY, H E. pursuant to 10 CFR 50.90, hereby submit Amendment Application No. 151, Supplement 1.

This amendment application consists of Proposed Change Number (PCN)-452, Supplement I to facility Operating License No. NPF-10.

PCN-452 is a request

}5 9 1 to revise Unit 2 Technical Specification 3.5.2, "ECCS-Operating," to extend the allowed outage time from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for a single Low Pressure Safety Injection train.

Supplement I adds a new TS 5.5.2.14, " Configuration Risk Management Program."

The purpose of the Configuration Risk Management Program (CRMP) is to ensure that a proceduralized Probabilistic Risk Asssessment-informed process is in place that assesses the overall impact of plant maintenance on plant risk.

Implementation of the CRMP will enable appropriate actions to be taken or

$g.1 decisions to be made to minimize and control risk when performing on-line maintenance for Systems, Structures, and Components with a risk-informed Completion Time. TS 5.5.2.14 will be applicable to TS 3.5.2 because the Completion Time for'TS 3.5.2 is a " risk-informed Completion Time."

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. Subscr! bed on this

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,1998-Respectfully submi ted.

SOV1HERNCALIFORNIAEDISONjCOMPANY f

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Vice-Pres ent i

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, personally known to me to be the person whose nllme is subscribed to the within instrument and acknowledged to me that he executed the same in his authorized capacity, and the by his signature on the instrument'the person, or the entity upon behalf o which the persoiNcted, executed the instrument.

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'l ENCLOSURE-(PCN452, Supplement 1)

-j; DESCRIPTION AND SAFETY ANALYSIS OF PROPOSED CHANGE NPF-10/15-452, SUPPLENENT-1 5 qp,1 '

.This is a request to revise the San Onofre Units 2 and 3 Technical 3.5.2, "ECCS Operating" and add a new TS 5.5.2.14, iSpecification (TS)k Management Program,- to be applicable to TS~ 3.5.2."

- Configuration Ris i

Existino Tech'nical Soecifications Unit 2:

See Attachment "A"-

Unit-3:-. See Attachment "B" Proposed Specifications Unit 2:=

See Attachment "C" Unit 3:

-See Attachment "D" DESCRIPTION OF PROPOSED CHANGES In-TS 3.5.2, "ECCS-Operating," the Completion Time for a single Low Pressure Safety injection (LPSI) train is being extended from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days with the other LPSI train operable.

Included in Attachment "C" for Unit 2 and Attachment "0" for Unit 3, respectively, are revised LC0 page 3.5 4 and revised Bases pages B3.5-16, B3.5-17, B3.5-18,-and B3.5 20a.

Due to text overflow, Bases pages B3.5-19 and Ag. 'l 83.5-20 are included for completeness.

Supplement I adds a new TS 5.5.2.14, " Configuration Risk Management Program."

-The purpose of the Configuration Risk Management Program (CRMP) is to ensure that.a )roceduralized Probabilistic Risk Assessment-informed process is in place t1at assesses the overall impact of plant maintenance on plant risk.

5 g.1 l Implementation of the CRMP will enable appropriate actions to be taken or decisions to be made to minimize and control risk when aerforming on-line maintenance for Systems,. Structures, and Components wit 1 a risk-informed Completion Time. TS 5.5.2.14-will be applicable to TS 3.5.2 becaust the Completion Time for TS 3.5.2 is a " risk-informed Completion Time."

~ BACKGROUND San Onofre Units 2 and 3 are each equipped with two LPSI trains. A LPSI train consists-of one LPSI pump and two injection flow paths, including motor-operated valves. ~ The LPSI-trains, in combination with the two High Pressure SafetyLInjection'(HPSI) trains, form the two redundant Emergency Core Cooling (ECCS): subsystems. The two LPSI pumps are high volume, low head centrifugal type pumps designed to inject large cuantities of borated water into the Reactor Coolant System (RCS) to flood and cool the core during the early stages of a large break Loss of Coolant Accident (LOCA).

During normal c

' shutdown-operation (Modes 4, 5, and 6), the LPSI pumps also provide shutdown

.. cooling flow to the reactor core.

In:this configuration, the LPSI pumps take suction from the RCS hot' leg through the Shutdown Cooling. Heat Exchanger

-(SDCHX) and discharge cooler water into the RCS cold leg.

1

s LThe-LPSI pumps take suction from the Refueling Water Storage Tank (RWST) during'the injection phase of a LOCA event.. The bora*ed watercis pumped to a common LPSI discharge header consisting of four injection lines with-individual injection valves prior to entering containment. Once inside containment, the LPSl!!njection lines combine with the HPSI and Safety

' Injection. Tank -(SIT) injection lines' and: flow is directed independently

'through.each of the four RCS cold leg's into the reactor vessel.

The LPSI system pumps automatically start and the valves open upon receipt of a Safety

_ Injection Actuation Signal (SIAS). When the RWST inventory is' drawn down-during the injection phase a low RWST level signal produces-a Recirculation:

-Actuation Signal-(RAS). The RAS secures the LPSI pumps, opens the Containment Emergency Sump (CES) isolation valves,-and shifts the suction of the HPSI pumps and the Containment Spray pumps to the CES.

Thel ECCS is de' scribed =in Section 6.3 with the I PSI pumps specifically I

- described in Section 6.3.2.2.2 of the San Ono" e Units 2 and 3 Updated Final:

Safety Analysis Report (UFSAR).

DISCUSSION OF CHANGE The San Onofre Units 2 and 3 Technical Specifications (TSs) 1 dress the LPSI as a portion of the ECCS subsystem.

TS 3.5.2 requires two independent ECCS subsystems to be operable. With one ECCS subsystem inoperable, based upon any com)onent inoperabilit.v, the subsystem must be returned to operability within 72 1ours. The proposed change will allow up to 7 days to restore one LPSI train to operable status (when the other LPSI train is operable) should that be the cause for ECCS subsystem inoperability, i

The Combustion Engineering Owners Group (CEOG) Report CE NPSD-995, " Joint Applications Report for Low Pressure Safety injection System Completion Time Extension," supports this change utilizing current Probabilistic Safety Analysis (PSA) methodologies to address the change in risk of the Completion Time extension when compared with the current TS time limitations.

The CE0G study considered and categorized the change in risk into "at power risk," " transition risk," and shutdown risk." Consideration of the risk factors impacted by the extension in Completion Time from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days demonstrates a negligible increase in "at power risk" (less-than a 0.3%

= increase in average core damage frequency for all Combustion Engineering (CE) plants and-less than a 1.5% increase in average core damage frequency for San Onofre Units 2 and 3). To perform a more comprehensive assessment of the overall change in risk, an accounting for avoided risks associated with reducing power and transitioning to hot or cold shutdown is considered. This

. transition risk" is important in understanding the tradeoff between shutting

~down the plant to comply with the TS Action Statement, and restoring the LPSI

-train to operability.while at power. Also of importance is.the risk avoided based on.LPSI system maintenance while in cold shutdown, or " shutdown risk."

Each' time the. plant is placed in cold shutdown, the LPSI system-is required for decay heat removal in the shutdown cooling mode of operation. Any maintenance performed on the LPSI system during shutdown cooling operation adds to-the 2

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/

l risk of losing shutdown cooling.

Therefore, : performing-LPSI system maintenance with'the. unit on-line, when the LPSI system _istnot normally'in-demand,- represents a decrease in " shutdown risk."

The resulta of. the CEOG integrated assessment-of the overall risk associated with the adoption of the proposed LPSI system Completion Time extension- -

concluded that.the change in core damage. frequency:due to this. Completion Time extensionisinsignificant(lessthana0.3%increaseinaveragecore_ damage:

frequency for all CE plants and less than a 1.5% increase in average core damage frequency for San Onofre Units 2 and 3). -Additionally, there~is a reduction in overall plant risk when this increase in risk is offset by.the reduction in transition and shutdown-risk.

It is the conclusion of the CEOG study that the overall_ plant impact will either be risk beneficial.. or at.the l

-very least, risk neutral.

As part of the CEOG study an assessment was-performed on the impact _of the proposed Completion Time extension' on large early release scenarios. The.

Jassessments of the three classes of events-(containment bypass, severe accidents accompanied by loss of containment isolation, and containment failure associated with energetic events in containment) considered for these scenarios concluded that the-increased unavailability of one LPSI will result-in a negligible impact on _the large early release probabilitv for San Onofre.

To' ensure plant safety is maintained and monitored San Onofre will implement a Configuration Risk Management Program (CRMP), which is to be applicable to TS 3.5.2.-

l.

Purpose of CRMP The purpose of the Configuration Risk Management Program (CRMP) is to ensure that a proceduralized Probabilistic Risk Assessment (PRA)-

informed process is in place that assesses the overall impact of plant maintenance on plant risk, implementation of the CRMP will enable appropriate actions to be taken or decisions to be made to minimize and control-risk when performing-on-line maintenance for Systems, Structures,- and Components (SSCs) with a risk-informed Completion Time.

2.

Scope of CRMP j,

The scope of the' SSCs included in the CRMP are those SSCs considered High Safety Sig'11ficant per the' Maintenance Rule regulatory guide (Regulatory Guide 1.160, Rev. 2).

--The Configuration Risk Management Program (CRMP) includes the following components:and' key elements:

Components-

.a.

Risk Assessment Tool b.

Tier 2-restrictions c.

Level,2 and External Events d.-

Decision Making Process e..

Associated Procedures l-

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Key Element 1. = Implementation of CRMP The intent of the CRMP is to implement-a(3) of the Maintenance g'

Rule l(10CFR50.65) with respect to on-line maintenance for risk-informed technical specifications, with the following additions /

clarifications:

a..

The scope of SSCs to be included in the CRMP will be the-SSCs considered High Safety Significant per Regulatory Guide 1.160,- Rev. 2.

b.

The CRMP assessment tool is PRA informed,.and may be in the form of either a risk matrix, an on-line assessment, or a direct PRA assessment.

c.

CRMP will be invoked as follows for:-

Risk-Informed Inoperability: A risk assessment will be performed prior to entering the LC0 Condition for preplanned activities. For unplanned entry into the LC0 Condition, a risk assessment will be performed in a timeframe consistent with the plant's Corrective Action Program..

Additional SSC Inoperability and/or Loss of Functionality:

When in the~ risk-informed Completion Time, if an additional high safety significant SSC becomes inoperable /non-functional, a risk assessment shall be performed in a g"fEi timeframe consistent with the plant's Corrective Action

Program, d.

Tier 2 commitments apply for planned maintenance only, but will be evaluated as-part'of the Tier 3 assessment for unplanned occurrences.

Key Element 2.

Control & Use of the CRMP Assessment Tool a.

Plant modifications and procedure changes will be monitored, assessed, and dispositioned.

Evaluation of changes in plant configuration or PRA model features can be dispositioned by implementing PRA model changes or by the qualitative assessment of the impact of the changes on the CRMP assessment tool.

This qualitative assessment recognizes that changes to the PRA take time to implement and that changes can be effectively compensated for without compromising the ability to make sound engineering judgments.

Limitations of the CRMP assessment tool are identified and understood for each specific Completion Time extension.

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, b.

Procedures exh for the control and application of CRMP assessment tools, including description of process when

-outside the scope of the CRMP assessment tool.

Key Element 3.,

Level 1 Risk-Informed Assessment The.CRMP assessment tool' is based on a Level 1, at power, internal events PRA model.

The CRMP assessment may use any combination of quantitative and qualitative input.

Quantitative assessments can include reference to a risk matrix, pre existing calculations, or new PRA analyses, a.

Quantitative assessments should be performed whenever.-

necessary for sound decision making, y

4 b.-

When quantitative assessments are not necessary for sot.nd decision making, qualitative: assessment; will be performed.

Qualitative assessments will consider applicable, existing insights from quantitative assessments previously performed.

Key Element 4.

Level 2 Issues / External Events External events and Lcvel 2 issues are treated qualitatively and/orquantitatively.

Guidance for implementing the CRMP_ is provided by plant procedures.

SAFETY ANALYSIS The proposed change described above shall be deemed to involve a significant hazards consideration if there is a positive finding in any one of the

-following areas:

1.

.Will operation of the facility in accordance with this proposed change involve a significant increase in the probability ur consequences of an accident-previously evaluated?

Response

No The Low Pressure Safety Injection (LP!,1) system is a part of the Emergency Core Cooling System (ECCS) subsystem.

Inoperable LPSI components'are not considered to be accident initiators.

Therefore, this change does not involve an increase in the probability of an-accident previously evaluated.

The LPSI system is pr.imarily designed to mitigate the consequences of a large loss of Coolant Act.ident (LOCA). This proposed change does not-

.-affect any of the assumptions used in the deterministic LOCA analysis.

Therefore, the consequentes of. accidents previously evaluated do not -

change.

5

.P To fully evaluate the LPSI Completion; Time extension, Probabilistic-Safety AnalysisL.(PSA) methods were utilized. :The results of:these i

analyses show no significant> increase in core damage frequency.; As a

. result,.there would be no significant increase in the consequences of an accident-previously evaluated.-

The Configuration Risk Management Program 1siar Administrative Program that assesses. risk based on plant status. Adding:the requirement to implement this program for Technical Specification 3.5.2 does_ not affe:t by.1 the probability or the consequences of en acci e nt.

Therefore, this change does not involve-a significant increase in the probability or consequences of any accident previously evaluated.

2.

Will operation of the facility in accordance with this proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response:- No This proposed change does not change the design, configuration, or method of operation of the plant. Therefore, this change does nal

- create the possibility of a new or different kind of accident-from any previously evaluated.

3, Will operation of the facility in accordance with this proposed change

. involve a significant reduction in a margin of safety?

Response

No The proposed change does not affect the limiting conditions for operation or their ba es that are used in the deterministic analyses to establish the margin of safety. PSA evaluations were used to evaluate

^

these changes.

Therefore, this change does agi involve a significant reduction in a margin of safety.

Safety and Sianificant Hazards Determination

. Based on the above Safety Analysis, it is concluded that: 1) the proposed change does not constitute a significant hazards consideration as defined by 10 CFR 50.92 and 2)Lthere is reasonable assurance that the health and safety of the public will nt be endangered by the proposed change. Moreover, because this action does not involve a-significant hazards consideration, it will also not result in a condition which significantly-alters the impact of tha station on-the environment as described:in the NRC Final Environmental Statament.-

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