ML20217E893

Application for Amends to Licenses NPF-4 & NPF-7,modifying Insp Frequency of EDGs & Establishing Configuration Risk Mgt Program to Support Risk Informed Tech Specs

ML20217E893
Person / Time
Site:	North Anna
Issue date:	03/25/1998
From:	Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20217E897	List: ML20217E893 ML20217E901
References
98-071, 98-71, NUDOCS 9803310198
Download: ML20217E893 (11)

Text

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WGINIA Ei.Ecruic AND POWEH CON 1PANY Riesissos o, h o:N A 23261 March 25, 1998  ;

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1 U.S. Nuclear Regulatory Commission Serial No.98-071 I Attention: Document Control Desk NL&OS/GSS/ETS R0 Washington, D.C. 20555 Docket Nos. 50-338 50-339 I

License Nos. NPF-4 NPF-7 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 PEOPOSED TECHNICAL SPECIFICATION CHANGE RC Nf1GURATION RISK MANAGEMFET PROGRAM FOR RISK-INFORMED ALLOWED OUTAGE TIMES Pursuant to 10 CFR 50.90, Virginia Electric and Power Company requests amendments, in the form of changes to the Technical Specifications and to Faci lity Operating License Numbers NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively. The proposed changes will modify the inspection frequency of the Emergency Diesel Generators (EDG) and establish a Configuration Risk Management Program to support risk informed Technical Specifications. These changes supplement our risk informed fourteen day EDG allowed outage time Technical Specifications changes submitted on November 18,1997. A discussion of the proposed Technical Specifications changes is provided in Attachment 1.

The proposed Technical Specifications changes have been reviewed and approved by the Station Nuclear Safety and Operating Committee and the Management Safety Review Committee. It has been determined that the proposed Technical Specifications changes do not involve an unreviewed safety question as defined in 10 CFR 50.59 or create a significant hazards consideration as defined in 10 CFR 50.92. The proposed Technical Specifications changes are provided in Attachment 2. The basis for our determination that these supplemental changes do not involve a significant hazards consideration is provided in Attachment 3.

If you have any further questions, please contact us.

Very truly yours,

[M7 James P. O'Hanlon gx Senior Vice President - Nuclear o' 9803310198 980325 ,

PDR ADOCK 05000338 P PDR

p Attachments {

-1. Discussion of Changes .

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2. Proposed Technical Specification Changes .  !

3. Significa6t Hazards Consideration Determination

- Commitments made in this letter: 3

1. There are no commitments in this letter.

cc: U.S. Nuclear Regulatory Commission Region 11 Atlanta Federal Center.

61 Forsyth Street, SW l-i Suhe 23T85 Atlanta, Georgia 30303 l Mr. M. J. Morgan . )

NRC Senior Resident inspector North Anna Power Station Commissioner

.' Department of Radiological Health

! Room 104A 1500 East Main Street Richmond, VA 23219 L

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1 COMMONWEALTH OF VIRGINIA )

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COUNTY OF HENRICO  :)-

The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by R. F. Saunders, who is Vice President - Nuclear Engineering and Services, for J. P. O'Hanlon who is Senior Vice President - Nuclear, of Virginia Electric.and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this [5Eday of du2; .19.71 My Commission Expires: do 3/ .1998 Vh& s hua Notary P'ublic h

(SEAL)

. ;. 4 3 ATTACHMENT 1 DISCUSSION OF CHANGES .

VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA UNITS 1 AND 2

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placussion of Changes introduction and Background On September 1,1995 Virginia Electric and Power Company (Virginia Power) requested amendments, in the form of changes to the Technical Specifications, to Facility Operating License Numbers NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively. The originally proposed changes would permit a single outage of up to 14 days for each emergency diesel generator (EDG) once every 18 months in order to perform preventive maintenance. This request was amended on November 18,1997 to request a 14-day Allowed Outage Time (AOT) for any reason.

On January 13,1998, the NRC staff requested additional information to complete the review of the proposed changes and incorporation of a Configuration Risk Management Program in the Administrative Section of Technical Specifications. The proposed change will incorporate a Configuration Risk Management Program into the Administrative Section of Technical Specifications.

In addition, Technical Specification 4.8.1.1.2 requires a thorough preventive maintenance inspection of the EDG's every 18 months. However, the Fairbanks Morse Owners Group (FMOG) has endorsed up to a two-year interval between such maintenance, based upon extensive industry experience. The EDG manufacturer, Fairbanks Morse, has recently endorsed this interval. Virginia Power therefore proposes to extend the current.18-month Technical Specifications requirement to 24 months. The increased interval will reduce EDG unavailability while still supporting the EDG operability requirements, once the interval is approved for Technical  !

Specifications implementation. l i

The Configuration Risk Management Program will ensure that a proceduralized Probabilistic Risk Assessment (PRA) informed process is in place that assesses the overall impact of maintenance on plant risk. These changes are administrative in nature and do not affect the design or operation of any plant system, structure or component.

Further, the increased maintenance interval will continue to support the EDG operability requirements. Therefore, incorporating a risk management program and the FMOG's l preventive maintenance interval into Technical Specifications does not create an I unreviewed safety question or a significant hazards consideration.

Discussion Configuration Risk Management Program. To ensure plant safety is maintained and monitored, North Anna will implement a Configuration Risk Management Program (CRMP), which is to be applicable to risk-informed allowed outage times. No risk-informed allowed outage times are presently in place.

Puroose 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 maintenance on plant risk.

Implementation of the CRMP will' enable appropriate actions to be taken or Page 1 of 6

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1 decisions to be made to minimize and control risk when performing on-line maintenance for Systems, Structures, and Components (SSCs) with a risk-informed allowed outage time.

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

Comoonents a Risk Assessment Tool

b. Tier 2 (Instantaneous Risk) Restrictions

c. Level 2 (Large Early Release Frequency Evaluation) and Extemal Events

d. Decision Making Process

e. Associated Procedures Key Element 1 -Implementation of CRMP The CRMP implements the Virginia Power program for on-line maintenance evaluation as per Maintenance Rule (10 CFR 50.65) paragraph a(3) for risk-informed technical specifications, with the following additions / clarifications:

a. The scope of Systems, Structures and Components (SSCs) to be included in the CRMP will be the SSCs considered Risk Significant per the Virginia Power Maintenance Rule program which is based on 10 CFR 50.65.

b. The CRMP assessment tool is PRA informed, and may be in the form of 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 risk-informed Limiting Condition for Operation (LCO) Action Statement for planned activities. For unplanned entry into the LCO Action Statement, a similar risk assessment will be performed shortly thereafter in accordance with the plant's planning and scheduling procedures.

Additional SSC Inoperability and/or Loss of Functionality: When in the risk-informed Action Statement, if an additional risk significant SSC becomes inoperable, a risk assessment shall be performed in accordance with the plant's planning and scheduling procedures.

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

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.C .a 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 Allowed Outage Time (AOT).

b. Procedures exist 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 (Core Damage Frequency) Risk-Informed Assessment The CRMP assessment tool is based on a Level 1, at power, intemal 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 j sound decision making.

b. When quantitative assessments are not necessary for sound decision making, qualitative assessments will be performed. Qualitative assessments will consider applicable, existing insights from quantitative assessments previously performed.

Kev Element 4 - Level 2 (Large Early Release Frequency) Issues /Extemal Evonts -

Extems.1 events and Level 2 issues are treated qualitatively and/or quantitatively. I Guidance for implementing the CRMP is provided by plant procedures.

EDG' Preventive Maintenance Interval. The Fairbanks Morse' Owners Group has recommended an interval of. up to' 24 months between preventive maintenance inspections. LThe EDG manufacturer, Fairbanks Morse,'has endorsed this intental, increasing the current Technical Specifications interval from 18 to 24 months'will

substantially reduce unavailability, in addition to _ making ~ resources available for other needs. Reliability'will benefit from more detailed maintenance procedures as prepared by the . Owners' Group.

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' Core Damage Frecuency -

[A PRA model update _-has recently been completed for North Anna. The ~ following

- information is provided as requested by the NRC Staff.

The sensitivity of the CDF due to the model update, the 14-day AOT, the 24-month 1

maintenance interval and other key factors is summarized in the following Table. ,

Core Damage Frequency.lmpact Analysis Individual Plant . September 1, Update of 9/95 Proposed Examination - 1995 Submittal Calculation; . PM Interval -

Model. Original PRA June 95 November 97 - November 97 Altemate AC. No Yes Yes Yes DG Installed EDG AOT 72 Hours 14 days 14 days 14 days Preventive 18 months 18 months 18 months 24 months Maintenance Interval Core Damage 6.8e-5 4.2e-5 3.58e-5 3.56e-5 Frequency Large Early . Not Calculated . Not cal..Jated 4.679e-6 4.676e-6 Release Frequency Specific Changes Configuration Risk Management Program: Establish new section 6.8.4.g for Units 1 and 2 as followsj The Configuration Risk Management Program (CRMP) provides a procedurcilzed risk-

-informed assessment to manage the risk associated with equipment inoperability. ' The

- program applies to technical specification structures, systems, or components for which

- a risk-informed allowed outage time has been granted. The program shall include the

following elements:

- 1. -: Provisions for the control and implementation of a Level 1, at power,

'intemal events,1PRA-informed methodology. The assessment shall be capable of evaluating the applicable plant configuration.

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2. Provisions for performing an assessment prior to entering the LCO Action Statement for planned activities.

1 Provisions for performing an assessment after entering the LCO Action 3.

Statement for unplanned entry into the LCO Action Statement.

4. Provisions for assessing the need for additional actions after the discovery of additional equipment out of service conditions while in the LCO Action Statement.

5. Provisions for considering other applicable risk significant contributors such as Level 2 issues and extemal events, qualitatively or quantitatively.

Current risk-informed actions statements include: Action 3.8.1.1.b

- Action Statement 3.8.1.1.b: To ensure that the operators are aware of the current risk-informed action statements we are including " Risk-informed" at the beginning of the action statement as an operator aide. For example, "(Risk-informed) With one EDG of 3.8.1.1.b inoperable..."

EDG Preventive Maintenance Interval: The Technical Specification 4.8.1.1.2 requirement for preventive maintenance every 18 months will be changed to every 24 months as per the recommendation of the Fairbanks Morse Owners Group.

Basis of TS 3.8.1 and 2: The Basis of TS 3.8.1 and 2 was revised in our November 18,

- 1997 submittal to discuss the risk-informed EDG allowed outage time and the associated administrative controls. The proposed Basis is being revised to discuss the Configuration Risk Management Program and the control of plant equipment during the 14-day allowed outage time as follows:

Delete the following sentence from paragraph 4 on TS page B 3/4 8-1:

" Removal of other components from service during the action statement is govemed by the administrative procedure."

And replace it with the following sentence:

"A Configuration Risk Management Program (CRMP) defined in Administrative Control Section 6.8.4.g is implemented to evaluate risk associated with the EDG outage."

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Safety Significance incorporating : a Configuration Risk Management Program into Technical

. Specifications does not affect plant operation or design. The Configuration Risk Management Program will ensure that a proceduralized. Probabilistic Risk Assessment (PRA) Informed process is in place that assesses the overall impact of maintenance on plant risk. In addition, the revised EDG preventive maintenance interval still meets the Owners Group recommendations for supporting its operability requirements. Thus, e Operation under the proposed Technical Specifications changes does not increase the probability of occurrence or.the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report.

Adoption of the proposed CRMP is administrative in nature and establishes the minimurn controls necessary to evaluate the plant risk during plant operations.

The plant design and operation are not impacted by these changes. Further, the EDG reliability is not reduced by the maintenance interval increase. Therefore, the EDG's will remain operable to perform their function of supporting accident mitigation equipment with emergency electrical power. Therefore, neither the probability of occurrence nor the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report are increased.

. The proposed Technical Specifications changes do not create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis report.

Including the CRMP and the EDG Owners Group maintenance interval in the Technical Specifications does not change any method of operation or create any new modes of operation or accident precursors. Therefore, it is concluded that no new or different kind of accident or malfunction from any previously evaluated has been created.

. The proposed Technical Specifications changes do not result in a reduction in margin of safety as defined in the basis for any Technical Specificat;ons.

Incorporating the CRMP into the administrative sections of the Technical Specifications does not affect any accident analysis assumptions or change any Technical Specifications criteria. The increased EDG maintenance interval will {

still enable the EDGs to support accident mitigation equipment which maintains safety margins. Therefore, the margin of safety as defined in the basis for any Technical Specification is not changed.

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ATTACHMENT 2 TECHNICAL SPECIFICATIONS CHANGES VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA UNITS 1 AND 2 r