ML17332A694

Revises Schedular Commitments for Modifying Discrepant Piping &/Or Pipe Supports

ML17332A694
Person / Time
Site:	Cook
Issue date:	03/20/1995
From:	Fitzpatrick E INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AEP:NRC:1100C, NUDOCS 9503270137
Download: ML17332A694 (10)

Text

P R.ICHOR.IMY'CELERATED RIDS PROCESSING) ~

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESS'1ON NBR:9503270137 DOC.DATE: 95/03/20 NOTARIZED: NO DOCKET FACIL:50-315 Donald C.

Cook Nuclear Power Plant, Unit 1, Indiana M

05000315 50-316 Donald C.

Cook Nuclear Power Plant, Unit 2, Indiana M

05000316 AUTH.NAME AUTHOR AFFILIATION FITZPATRICK,E.

Indiana Michigan Power Co. (formerly Indiana

& Michigan Ele RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Revises schedular commitments for modifying descrepant piping

& or pipe supports.

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Indiana Michigan Power Company P.O. Box 16631 Columbus, OH 43216 Harch 20, 199)

AEP:NRC:1100C Docket Nos.:

50-315 50-316 U. S. Nuclear Regulatory Commission ATTN:

Document Control Desk Washington, D.C.

20555 Gentlemen:

Donald C.

Cook Nuclear Plant Units 1 and 2

PIPING SYSTEM MODIFICATIONS The purpose of this letter is to revise AEP:NRC:1100A and AEP:NRC:1100B schedular commitments for modifying discrepant-piping and/or pipe supports.

This includes the Donald C.

Cook Nuclear Plant (CNP) Large Bore Piping Reconstitution Program (LBPRP) and the Inservice Inspection (ISI)

Program, as well as discrepancies discovered by any other inspection process.

In conversations with the NRC staff subsequent to issuance of AEP:NRC:1100A, we committed to complete the LBPRP analyses by 1996 and to fix any discrepant supports identified by the analyses over four refueling outages for each unit.

We were to make reasonable efforts at scheduling piping and pipe support modifications, and we were to notify Region III when modifications could not be completed prior to unit startup.

In submittal AEP:NRC:1100B, we instituted a six-month planning window prior to a unit refueling outage for correcting LBPRP discrepancies discovered by analysis.

In addition, we proposed not to notify Region III of modifications deferred until the next outage.

Initially, the six month planning window was acceptable because it fitwithin our defined time frame for establishing the work scope of a refueling outage.

However, as our scheduling process has evolved and been refined over the past two years, the six month window is now inconsistent with the current scheduling milestones.

This makes it very difficult to effectively schedule repairs for piping and pipe support modifications.

Therefore, we propose to eliminate the six month planning window requested in our August 25, 1993 letter (AEP:NRC:llOOB) and apply the established scheduling milestones discussed in the attachment for piping system modifications performed in both outage and non-outage situations.

27C it.i 9503270137 950320 PDR ADOCK 05000315 P

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U.S. Nuclear Regulatory Commission Page 2

AEP:NRC:1100C In the unlikely event that discrepancies are identified that affect operability of a piping system, the necessary modifications will be implemented on a schedule consistent with the applicable technical specifications, and appropriate reporting requirements will be executed.

We remain committed to complete the LBPRP analyses and to fix any discrepant piping and pipe supports identified in the LBPRP analyses and the ISI Program.

However, to conform to the proposed scheduling philosophy, implementation of modifications resulting from the LBPRP analysis may not be completed until UlR98 and U2R99 refueling outages for Units 1 and 2, respectively.

Therefore, in order to control the resources available for both the analysis and design

packages, the analysis work may continue into 1997, which is beyond our original 1996 timeframe referenced in AEP:NRC:1100B.

We believe that the elimination of the six-month planning window, and the implementation of the current scheduling practices for piping system modifications will facilitate more successful refueling outages, and safe and economical implementation of the necessary modifications.

As such, Cook Nuclear Plant will use the revised

schedule, as discussed in the attachment, for modifying discrepant piping systems.

Sincerely, E.

E. Fitzpatrick

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Vice President eh Attachment CC:

A. A. Blind G. Charnoff J.

B. Martin NRC Resident Inspector

- Bridgman NFEM Section Chief J.

R. Padgett

ATTACHMENT TO AEP:NRC: 1100C DONALD C.

COOK NUCLEAR PLANT REVISION OF THE SCHEDULING WINDOW FOR MODIFICATIONS TO PIPING AND PIPE SUPPORT SYSTEMS

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Attachment to AEP:NRC:1100C Page 1

The following information is provided to describe the rationale for modifying the scheduling philosophies for piping syst: em modifications.

BPRP BACKGROUND A 1989-1990 study of a representative sample of safety-related piping systems at CNP was completed to evaluate piping systems.

This information was presented at a conference which took place at

'the NRC Region III office on June 7, 1990.

As a result of this study and interactions with the

NRC, a series of walkdowns were performed in 1991/1992 on the large bore piping systems to evaluate the ability of the piping systems to meet the Interim Acceptance Criteria (IAC) established in AEP:NRC:1100A.

The conclusions of the walkdowns indicated that the large bore piping systems at CNP are safe to operate in their current condition.

The results of the walkdowns matched the findings of the evaluation of numerous piping and pipe support related discrepancies identified through the condition report system prior to establishing the LBPRP.

The wording of AEP:NRC:1100A, wherein we documented commitments relative to the evaluation of piping systems, states

that, "In

summary, piping and/or piping supports found to exceed the FSAR allowable stresses for the design basis conditions will be returned to within the original design requirements.

Systems that are discovered in this condition will be considered operable if the calculated stress levels meet the limits of the interim acceptance criteria described in the appendix."

In meeting those commitments, we would like to reiterate that a comprehensive study performed in 1989/1990 and subsequent set of walkdowns performed in 1991/1992 were used to justify the operability of safety related piping systems in their existing configuration.

In addition, it was stated in a review of the LBPRP by the NRC in December,

1991, (Inspection Reports Nos.

50-315/91028 and 50-316/91028)

that, "Although both systems did not meet the design criteria, the operability of the systems was demonstrated by the licensee."

PIPE SUPPORT MODIFICATION PLANNING WINDOW In our submittal dated August 25, 1993 (AEP:NRC:1100B), we requested a

six month planning window for work associated with the implementation (before unit restart) of piping and/or pipe support modifications identified through the LBPRP.

The current planning window of six months results in a maximum time of 24 months that a hanger would remain in its discrepant configuration.

Unfortunately, this limited planning window is now creating difficulties with the planning and execution of the outages and timely implementation of the modifications.

Attachment to AEP:NRC:1100C Page 2

The current scheduling process at Cook Nuclear Plant organizes work activities in two different fashions; one being outage and the other being non-outage related.

In addition, non-outage work is also broken down into a Functional Equipment Group (FEG) cycle.

A FEG consists of groups of components that support a particular system.

Scheduling of predictive and corrective maintenance activities is organized by FEG cycles.

These cycles are approximately 12 weeks in duration and ensure that train orientation is considered when taking equipment out of service for maintenance.

When AEP:NRC:llOOB was submitted, the six month window was considered adequate to provide the necessary processing time for developing the design drawings, proper planning, scheduling, and execution of the modifications.

This has created confusion because that commitment was made in reference to work that can only be performed during a refueling outage and there is no specific direction to address piping modifications that can be completed during normal operation.

It has become necessary to establish two different planning processes; one for work

. that can only be performed during a

refueling outage, and one for work that can be performed non-outage and within the FEG scheduling process.

Therefore, we propose to use our existing scheduling methods for implementing piping system modifications that can be scheduled during normal operation.

This will require a

scheduling evolution of three FEG cycles (approximately 36 weeks) for piping and pipe support modifications that have been identified.

The three FEG cycle evolution begins when design for the modifications are complete.

The planning window, or outage scope window, for outage related work is currently between sixteen and eighteen months prior to the refueling outage.

This time frame allows for resource allocation and in-depth planning activities to control refueling outage duration.

The same six month period established in AEP:NRC:1100B is no longer considered an adequate length of time.

We propose to apply our current scheduling process for repairing pipe support discrepancies during refueling outages.

The scheduling window for piping and pipe support modifications applies when an individual piping system analysis is complete and the required system modifications are identified prior to closing the refueling outage milestone date.

If the analysis is not complete by the refueling outage planning milestone

date, the modifications in that system would not be required to be submitted for scheduling until the next refueling outage planning window is established.

As stated

above, the current planning window of six months results in a maximum time of 24 months that

. a hanger would remain in its discrepant configuration.

The proposed scheduling change for outage related work would result in a maximum time of 36 months that a hanger would

Attachment to AEP:NRC:1100C Page 3

remain in its discrepant configuration.

We believe this does not significantly affect the health and safety of the public because the piping system will be functional if compared to the established interim acceptance criteria.

In the unlikely event that any piping system analyses performed identifies discrepancies that affect piping system operability (defined as outside the IAC), the necessary modifications will be implemented promptly in consideration of technical specification limitations and appropriate reporting requirements willbe executed.

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