April 19, 1999 LICENSEE: Duquesne Light Company (DLC) FACILITY: Beaver Valley Power Station (BVPS), Unit 1 SUBJECT: SUMMARY OF MARCH 11, 1999, MEETING WITH DLC STAFF TO DISCUSS ACTION PLAN FOR CORRECTING DESIGN DEFICIENCIES OF VARIOUS SMALL BORE PIPING SUPPORTS ON BEAVER VALLEY POWER STATION, UNIT 1 (BVPS-1) Background: In June, 1997, Duquesne Ught Company (DLC, the licensee) identified various design deficiencies on small bore (2 inch and smaller) piping supports at BVPS-1. Supports in the Reactor Coolant System Drain lines with identified deficiencies were corrected/modified to ensure that they meet Code requirements, and engineering reviewi of supports for other small bore safety-related piping were initiated. In October 1997, continuing evaluations, which were being conducted as part of the corrective actions for the issues identified in June 1997, identified three piping supports in the Chemical and Volume Control System which were inadequate. The licensee performed engineering evaluations for the associated piping to ensure that the affected lines would still perform their intended safety functions. Although this condition was notreportable under 10 CFR 50.73, the licensee submitted a voluntary Ucensee Event Report to the Nuclear Regulatory Commission (NRC) in November, 1997. Additionally, DLC continued with efforts to review the adequacy of supports for all safety-related small bore piping and implement corrective maintenance/ modification where needed. Discussion: On March 11, 1999, NRC staff met with representatives of DLC, Stone & Webster, and Wais & Associates, Inc. to discuss DLC's action plan for correcting small bore piping design deficiencies at BVPS-1. Specifically, to discuss technical aspects of the methodologies being used by DLC to evaluate adequacy of supports installed in BVPS-1, and DLC's schedule for completing any required repairs/ modifications that are identified by the ongoing evaluations. The licensee had requested this meeting. Enclosure I is a list of meeting attendees. Enclosure 2 is a copy of the licensee's handout material. DLC provided a brief background of the design codes and methodologies used in the original design and installation of safety related small bore piping supports for BVPS-1. Additionally, DLC gave a brief history of the supports which were identified to be non-conforming to design codes, and discussed the operability evaluations and corrective actions performed to date as well as those which are still ongoing. Based on questions asked by the NRC staff, the licensee provided the following clarifications or additional information: DLC's analysis to date has not addressed the effects of wet insulation weight on small bore piping operability. Depending on the piping location, type of insulation installed, ~fit1101.
Transcript
April 19, 1999
LICENSEE: Duquesne Light Company (DLC)
FACILITY: Beaver Valley Power Station (BVPS), Unit 1
SUBJECT: SUMMARY OF MARCH 11, 1999, MEETING WITH DLC STAFF TO DISCUSS ACTION PLAN FOR CORRECTING DESIGN DEFICIENCIES OF VARIOUS SMALL BORE PIPING SUPPORTS ON BEAVER VALLEY POWER STATION, UNIT 1 (BVPS-1)
Background:
In June, 1997, Duquesne Ught Company (DLC, the licensee) identified various design deficiencies on small bore (2 inch and smaller) piping supports at BVPS-1. Supports in the Reactor Coolant System Drain lines with identified deficiencies were corrected/modified to ensure that they meet Code requirements, and engineering reviewi of supports for other small bore safety-related piping were initiated. In October 1997, continuing evaluations, which were being conducted as part of the corrective actions for the issues identified in June 1997, identified three piping supports in the Chemical and Volume Control System which were inadequate. The licensee performed engineering evaluations for the associated piping to ensure that the affected lines would still perform their intended safety functions. Although this condition was notreportable under 10 CFR 50.73, the licensee submitted a voluntary Ucensee Event Report to the Nuclear Regulatory Commission (NRC) in November, 1997. Additionally, DLC continued with efforts to review the adequacy of supports for all safety-related small bore piping and implement corrective maintenance/ modification where needed.
Discussion:
On March 11, 1999, NRC staff met with representatives of DLC, Stone & Webster, and Wais & Associates, Inc. to discuss DLC's action plan for correcting small bore piping design deficiencies at BVPS-1. Specifically, to discuss technical aspects of the methodologies being used by DLC to evaluate adequacy of supports installed in BVPS-1, and DLC's schedule for completing any required repairs/ modifications that are identified by the ongoing evaluations. The licensee had requested this meeting. Enclosure I is a list of meeting attendees. Enclosure 2 is a copy of the licensee's handout material.
DLC provided a brief background of the design codes and methodologies used in the original design and installation of safety related small bore piping supports for BVPS-1. Additionally, DLC gave a brief history of the supports which were identified to be non-conforming to design codes, and discussed the operability evaluations and corrective actions performed to date as well as those which are still ongoing. Based on questions asked by the NRC staff, the licensee provided the following clarifications or additional information:
DLC's analysis to date has not addressed the effects of wet insulation weight on small bore piping operability. Depending on the piping location, type of insulation installed,
~fit1101.
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and postulated post-accident environment, this may be applicable to the BVPS-1 accident scenarios. DLC acknowledged this item for further review.
By use of analysis methods which are more refined than those used for the original design, the licensee is determining the capacities of generic support designs which are installed on BVPS-1. This effort is approximately 75% complete. Once this is complete, DLC will use a simplified approach which will include assessment of piping spans and determination of input loads to supports. These loads will then be compared to the support capacities to assess support acceptability.
In cases where the simplified method shows the supports to be unacceptable, the licensee will use specific as-built information for detailed computer analysis to determine support acceptability.
Some of the supports experience loading by moments which were not accounted for In the original design. DLC is working to Identify and correct these as part of the overall corrective action plan.
The original schedule for completing these corrective actions changed from the thirteenth refueling outage (2000) to the fifteenth refueling outage (2003) as a result of growth in the amount of work required to resolve the issue.
DLC discussed their plans for implementing corrective actions. The licensee stated that it is their intent to restore any deficient supports to be in conformance with the design codes. However, there may be some cases where DLC will request NRC approval to accept design discrepancies If other solutions are not practical (e.g. due to ALARA considerations or component inaccessibility). The licensee will be sequencing any needed component modifications into outage schedules as the need for this work Is identified rather than waiting until all evaluations are completed. Finally, DLC stated their intent to docket the approach they are using to resolve this issue via formal letter to be submitted to the NRC.
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The staff stated that the presentation gave them a better understanding of the analysis methodologies being employed by DLC to resolve small bore piping support issues on BVPS-1. Additionally, the staff requested that the NRC Senior Resident Inspector be provided with routine updates of progress and be notified of any significant changes in the completion schedule of the corrective action plan.
Original signed by:
Daniel S. Collins, Project Manager, Section 1 Project Directorate I Divison of Licensing Project Management Office of Nuclear Reactor Regulation
Docket No. 50-334
Enclosures: 1. List of Attendees 2. Ucensee's Handouts
cc w/encls: See next page
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The staff stated that the presentation gave them a better understahding of the analysis methodologies being employed by DLC to resolve small bore piping support issues on BVPS-1. Additionally, the staff requested that the NRC Senior Resident Inspector be provided with routine updates of progress and be notified of any significant changes in the completion schedule of the corrective action plan.
Original signed by:
Daniel S. Collins, Project Manager, Section 1 Project Directorate I Divison of Ucensing Project Management Office of Nuclear Reactor Regulation
Docket No. 50-334
Enclosures: 1. Ust of Attendees 2. Licensee's Handouts
cc w/encls: See next page
DISTRIBUTION: See next page
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S. Collins/R. Zimmerman B. Sheron J. Zwolinski/S. Black S. Bajwa M. O'Brien D. Collins C. Wu G. Shear D. Kern, Region I N. Perry, Region I A. Blough, Region I
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LIST OF ATTENDEES
MEETING BETWEEN NRC AND DLC STAFF TO DISCUSS ACTION PLAN FOR
CORRECTING DESIGN DEFICIENCIES OF VARIOUS SMALL BORE PIPING SUPPORTS
ON BEAVER VALLEY POWER STATION, UNIT I (BVPS-1)
MARCH 11, 1999
ORGANIZATION
D. Kern D. Collins C. Wu J. Cross S. Jain W. Kline M. Ackerman R. Hruby S. Loehlein M. Testa D. High T. Machgan J. Sasala M. Kelly T. Roman R. Bain E. Wais
SUBJECT: SUMMARY OF MARCH 11, 1999, MEETING WITH DLC STAFF TO DISCUSS ACTION PLAN FOR CORRECTING DESIGN DEFICIENCIES OF VARIOUS SMALL BORE PIPING SUPPORTS ON BEAVER VALLEY POWER STATION, UNIT 1 (BVPS-1)
*****ROUTING LIST*****
NAME
1. D. Collins
2. M. O'Brien
3. S. Baiwa
4.
5.
DATE
04/19/99
04/19/99
04/19/99
//99
I/99
6. Secretary - Dispatch
PLEASE DO NOT REMOVE THIS SHEET FROM PACKAGE
* CAN THIS DOCUMENT BE DELETED AFTER DISPATCH? YES _ NO
V-4f
*Z
zT
OpnngRmak
o Attendees, NRC - Dan Collins
- Glenn Dentel
- Dave Kern
- Geoff Wertz
- Cheng Wu
o Attendees,-BVPS - Mark Ackerman -- Bob Bain (SWEC) - Jim Cross - Ray Hruby - Sushil Jain
- Mark Kelly - Bill Kline - Mike Testa - Ed Wais, PhD (Wais
and Associates)
2
Ov0iiew
' Introduction
* History
* Operability
* Resolution plan
Conclusion
3
A^jA-t,-i to ec 0
ser
* Safety related small bore (2" and less) -ANSI B31.1 1967- S71 -field routed
-- sim plified m ethods cU,,cI 4uea1,t O5IS1-loL
* standard spans * support concentrated weights
standarized decal capacities
4
Introductio-
* Assess piping for acceptability S s
--tables,, homographs-"
* Design supports with sufficient capacity 750
-decal load rating s -- not necessary to know
precise load input to support
5
o July 1979 IEB 79-14 Rev. 1 -excluded non-computerized small bore piping
* September 1996 PR 960705 -- small bore piping overspans identified -- modifications performed -additional sampling performed - in conformance -pipe stress reconciliation standard developed
6
Histuy
HI~t~0
0 Current program instituted in 1997 * Condition Report (CR) required when a
deficiency is identified Requires followup and extent of condition -cause of deficiency investigated -corrective action
Program instrumental in identification of small bore design issues d 'II'
7
* June 1997 CR 970999 sliding suppo subject to high thermal.movement disengaged. . 5,,o, '
0 6 supports on excess letdown replaced * balance reviewed and found acceptable
-46iype not in code compliance 23 anchors modified gof p, •-T',e ./ --
additional anchors reviewed and found acceptable
8
.Histoty
1ý
2
C
H
Hislory
' October 1997 CR.971875 -assessed operability for conditions identified
by CR 970999 -3 anchors were determined to be beyond
operability limits -- system operability assessed and found
acceptable
13
I History I
-It~l
0 November 1997 CR 972079-heavy valve weights -discrepancies from standarized decal load
capacities -safety / non-safety related Q interfaces -operability evaluation performed
14
wc,.,- ,.,_ o -r • oAret.y
2*
.H9istr
16
I
I
Operabilit
o Safety related small bore piping and associated supports -P and ID review identification
-associated Q interfaces included
---650 isometrics and --2400 supports
Use of record drawings -- adequacy demonstrated by supplemental
walkdowns
18
* Evaluation assessed: -- system temperatures
-- span lengths -insulation -_ .e 5k+,,S4
- Q interfaces -reconciled heavy weight valves
-relief valves
-- seismic considerations
-large equipment movement 19_ ...
Operability
* Operability criteria document "-"Operability Evaluation for Small Bore Piping
Systems"
-followed GL 91-18 Rev. 1
o Operability assessment sheets -each piping isometric and support
- independent reviews
-docum entation
AI- $ALF 5 P60- ).~
20
* Reasonable assurance of operability of safety related small bore piping
* BCO 1-97-007 issued Next step is to resolve design discrepancies
21
o Safety-related small bore piping design discrepancy resolution
22
Rsui Plan
o Resolve design discrepancies -- define plan and timeframe
* Scope defined * Method established and under review o Safety-related small bore piping design
discrepancy resolution
35 I_
I
Conclusion,
f
Duquesne Unit Company SeaverValley Power Station Shlpplngport. PA 15077-0004
SUSHIL C. JAIN (412) 393-5512 Senior Vice President Fax (724) 643-8069 Nuclear Services May 17, 1999 Nuclear Power Dislion L-99-082
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001
Subject: Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Safety Related Small Bore Piping Evaluation Project
The purpose of this letter is to docket our plan for the Unit 1 Safety Related Small Bore Piping Evaluation Project (SBPEP) discussed in the NRC public meeting on March 11, 1999, at the Beaver Valley Power Station (BVPS).
A. Background and Current Operability
An assessment of the BVPS Unit 1 safety-related small bore (5 2" diameter) piping design was performed in 1997 to evaluate the extent of condition for design code discrepancies identified through the BVPS Corrective Action Program. This assessment included a review of approximately 650 isometric drawings, 2400 supports and associated interfaces between the safety related and non-safety related piping. The assessment concluded that the small bore piping systems at BVPS Unit 1, although not in full compliance with the design code of record, are safe to operate in their current condition. Based on this assessment, a Generic Letter 91-18, Revision I operability evaluation (BCO # 1-97-007) was developed and is currently in effect.
A project has been initiated to further evaluate the Unit 1 small bore piping to identify and resolve discrepancies from the design code of record, ANSI B31.1 1967-S71. This project is referred to as the Unit 1 Safety-Related Small Bore Piping Evaluation Project (SBPEP.)
B. Unit 1 Safety-Related Small Bore Piping Evaluation Project (SBPEP)
Engineering Standard ES-N-0 18, titled "Design Criteria Document for Evaluation of Small Bore Piping Systems" has been developed to provide details of the evaluation criteria to be used in the SBPEP. This standard defines the specific methodology that will be used to evaluate small bore safety related piping and pipe supports.
Beaver Valley Power Station, Unit No. 1 Safety Related Small Bore Piping Evaluation Project Page 2
ES-N-018 allows for a graded approach in the analytical methods (simplified or detailed
computer analysis) to be employed based upon the level of rigor necessary to evaluate
design code compliance. When employing conservative simplified methods (hand calculations or simplified computer analyses), verification of the as-installed configuration will not be performed. Verification of the as-installed configuration will
be performed when utilizing detailed computer analyses performed in conjunction with the Engineering Standard. Both simplified and detailed analysis methods are consistent with those described in BVPS Updated Final Safety Analysis Report Appendix B and meet the intent of the 1967 ANSI B3 1.1 Code.
The preferred resolution method for identified discrepancies will be to restore compliance with the original design code. However, alternative resolutions may be
submitted to the NRC for review when appropriate, (e.g., for inaccessible or high radiation locations).
Finally, as additional information is obtained, we will assess the impact on the existing operability evaluation. Although operability impacts are not anticipated, this assessment will provide added assurance that identified discrepancies do not change the basis for conclusions of the existing operability evaluation.
C. Schedule and Status
Systems are being prioritized for review based on risk and design insights. Should modifications be determined to be appropriate, a planning window approach will be used to determine the implementation schedule. Refueling outage related modifications identified at least 15 months in advance will be incorporated into the next refueling outage. Modifications may also be performed during non-outage periods and coordinated with the 12 week schedule.
Project work is in progress. Nuclear Engineering Department personnel performed selected small bore piping walkdowns in containment during the Spring 1999 Unit I surveillance outage. The purpose of these walkdowns was to obtain supplemental dimensional information pertaining to the piping supports for use in planned evaluations.
Completed actions include issuance of an approved project plan and the Engineering Standard. A project database defining piping and supports within the scope of this
project has been developed. Additional support walkdowns have been defined. Design evaluations are in progress and are expected to be completed prior to the end of 2001. The SBPEP will be completed prior to the conclusion of 1R15 (currently projected for March of 2003).
Beaver Valley Power Station, Unit No. 1 Safety Related Small Bore Piping Evaluation Project Page 3
As discussed in the NRC public meeting of May 11, 1999, at Beaver Valley Power Station, we believe that the above approach for implementing potential piping and pipe support modifications will provide for an orderly and safe resolution of the identified issues.
Sincerely,
Sushil C. Jain
Commitment
The SBPEP will be completed prior to the conclusion of IR15 (currently projected for March of 2003).
c: Mr. D. S. Collins, Project Manager : Mr. D. M. Kern, Sr. Resident Inspector
