ML18059A407
| ML18059A407 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 09/30/1993 |
| From: | Rogers D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9310040365 | |
| Download: ML18059A407 (14) | |
Text
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consumers Power David W. Rogers Plant Safety and Licensing Director l'OWERIN&
MICHIGAN'S l'RO&RESS Palisades Nuclear Plant:
27780 Blue Star Memorial Highway, Covert, Ml 49043 September 30, 1993 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - SAFETY RELATED PIPING REVERIFICATION PROJECT - PERIODIC STATUS - SEPTEMBER 1993 A meeting was held at NRC Headquarters on January 22, 1992 to discuss the Safety Related Piping Reverification Project (SRPRP}.
As documented in your February 13, 1992 letter, we committed to submit a status report for the SRPRP approximately every eight months.
Consumers Power Company's letter, dated October 30, 1992, provided the first of the periodic status reports.
Because the next eight month period was scheduled to coincide with the end of the 1993 refueling outage and to give us time to incorporate the results of the work completed during the outage, we revised our schedule for submitting the second status report to the end of the 1993 refueling outage.
Enclosed is the second status report.
It has become apparent that status reports are more appropriately tied to the results of the work completed during refueling outages.
Reports of the status following the refueling outages will replace the originally committed submittal of the status reports at approximately every eight month intervals.
Accordingly, we are changing our commitment to submit*status reports every eight months and instead will submit status reports following our refueling outages until we have completed our planned actions.
a:iw(~~
David W Rogers Plant Safety and Licensing Director CC: Administrator, Region III, USNRC Resident Inspector - Palisades Enclosure 04oo~s A CMS' ENERGY COMPANY
{\\VDI I (
ENCLOSURE.
Consumers Power Company Palisades Plant Docket 50-255 SAFETY RELATED PIPING REVERIFICATION PROJECT PERIODIC STATUS SEPTEMBER 1993 Septemb~r 3Q, 1993 3 Pages
Introduction SAFETY RELATED PIPING REVERIFICATION PROGRAM PERIODIC STATUS - SEPTEMBER 1993 1
The Safety Related Piping Reverification Program (SRPRP) was initiated to reverify the seismic design adequacy of large bore (> 2" nominal diameter) piping systems.
The scope consists of physical walkdowns of accessible piping and pipe supports, performance of analyses for both piping and supports to current design criteria, and implementation of required modifications.
The purpose of this report is to summarize the results of the recently completed Phases IIA and IIB of the program and to identify future program direction.
Scope Phase I of the program consisted of reverification of 18 piping stress packages containing approximately 300 pipe supports.
Phase I was completed as of October 1992 (CPCo lett~r to NRC dated October 30, 1992).
Phases IIA and IIB consisted of reverification of 13 piping packages containing 271 supports. Attachment A summarizes the Phase IIA and IIB stress package scope..
Walkdowns were initiated in February 1992. *Analytical work and installation of required modifications were complete as of September 10, 1993.
Due to changes in design criteria subsequent to Phase I, three stress packages from Phase I were identified as re~uiring reanalysis in conjunction with Phase IIA work.
No modifications were necessary as a result of the reanalysis of these three packages.
The changes in design criteria were agreed to between Consumers Power Company (CPCo) and the ~RC as a result of an NRC Special Team Inspection performed in 1991 (IR 91-202, dated August 2, 1991). These criteria became the basis for the SRPRP.
Current program as-built walkdown requirements include:
Visual verification of piping configuration; location of pipe supports and wall and floor penetrations; and unidentified and unintentional restraints Detailed measurement and verification of pipe support attributes, including member lengths, size and configuration of welds, gaps, spring hanger settings, etc.
2 Results - Phase llA and llB A total of 37 modifications resulted from the Phase llA and llB scope.
Only 3 of the modifications were inside containment. Nearly all outside containment modifications were completed prior to the start of the 1993 refueling* outage.
All remaining modification were completed during the refueling outage.
The exhibits provided in Attachment B summarize the reasons, root causes and root cause categories associated with the Phase IIA and IIB modifications.
Analyses have shown that, to date, no piping system has exceeded the interim operability criteria which were submitted to the NRC staff on November 22, 1989.
Trending At the completion of both Phases I, llA and llB, trending studies were performed and documented.
Based on root cause analyses of as-built and design.
discrepancies, the trending studies provide a basis for refocusing of requirements and processes for future program phases.
The exhibits contained in Attachment B show that nearly all of the Phase IIA and IIB modifications were due to design criteria changes (i.e., response spectra peak broadening, use of Regulatory Guide 1.60 spectra, localized effects due to integral welded attachments to pipe, relative seismic movements between buildings, etc.} and errors in previous analyses. As-built discrepancies by themselves did not lead to modifications. These re*sults are consi~tent with Phase I trending.
Based on the trending results to date, a refocusing of the walkdown process is warranted.
On the basis that as-built discrepancies have not led fo modificaitons, a revised walkdown process will be implemented which will allow less rigorous inspections of selected pipe support attributes. Specifically, there will be no walkdown requirement to t~ke precise readings of spring hanger load indicators and exact measurements of support member lengths, weld
- size and gaps. This is based on the results of all pipe supports analyzed to date (about 40% of the total number of supports i.n the program).
The current visual inspection criteria for piping configuration verification will remain unchanged.
Likewise, current requirements for pipe support inspections for missing and loose fasteners will continue as required per the Pipe Support Preventive Maintenance Program.
Future Program Direction As discussed above, the SRPRP walkdown process will be changed to incorporate revised inspection requirements for pipe supports.
Implementation of the revised process will be in conjunction with the
3 start of Phase IID walkdowns in November 1993.
Phase IIC walkdowns will continue to be performed to the current requirements.
The scope and stheduled completion dates for Phases IIC and IID are shown in Attachment C.
Phase IIC walkdowns are ahead of schedule and the modifications are to be completed by the end of the 1995 refueling qutage.
Remaining work wi 11 be performed on a continuing basis and a 11 SRPRP modification work is scheduled to be completed by the end of the 1996 refueling outage.
Our current assessment is that the program will be completed ahead -of schedule.
The results of Phase IIC and Phase.IID will be forwarded to the NRC after* the completion of the 1995 and 1996 refueling outag~.
Attachment A Consumers Power Company Palisades Plant Docket 50-255
. PHASE IIA/B SCOPE
SUMMARY
September 30, 1993
e e
PHASE IIA/8 SCOPE
SUMMARY
Page 1 of 1 STRESS NO. OF PHASE PACKAGE SYSTEM 110*
SUPPTS I IA 03320 Safety Injection, Containment Spray &
0 63 Shutdown CoolinQ llA 03325 SFP CoolinQ Pumo DischarQe 0
73 llA 03382 Service Water I
3 llA 03383 Service Water I
3 llA 03384 Servtce Water I
3 I IA 03385 Service Water I
3 llA 03386 Service Water I
32 llA 03387 Service Water I
27 llA 05901
'AFW Pumo Suet ion 0
1 llA 05902 *AFW Pumo Suction.
0 4
llA:
10 212 118 033'12 Comoonerit Cool fog Water.
0 33 118 03313 Component CoolinQ Water 0
7 118 03316' Service Water 0
. 19 118:
' 3
. 59 Totals 13 *stress Packages
.271 Supports
- Iriside/O.utside containment
Attachment B Consumers Power Company Palisades Plant
- Docket 50-255 MATRIX
SUMMARY
OF MODiFICATION ROOT CAUSES (Exhibit 5)
MATRIX
SUMMARY
OF ROOT CAUSE CATEGORIES
, (Exhibit 6)..
September 30, i993
Pal1sades Nuclear Plant Report No. SL-4848.
SRPRP Phase IIA/B EXHIBIT 5 - MATRIX
SUMMARY
OF MODIFICATION ROOT CAUSES Rev. 1 Trend1 ng Report STRESS PACKAGE 0
0 0
0 0
0 0
0 0
0 0
.0 0
HQ. OF ITEM 3
3 3
3 3
3 3
3 5
5 3
3 3
OCCUR-ROOT CAUSE*
3 3
3*
3 3
3 3
3 9
- 9.
3 3
3 EHCES BY
, NO.
2 2
8 8
8 8
8 8
0 0
1 1
1 ROOT
- r. ;.. $
0 5
2 3
4 5
6 7
1 2
2 3
6
- CAUSE I
REVISED SEISMIC CRITERIA 6
z 1
z 11 z
NEW Slfs 3
3 3
IWAs PREVIOUSLY NOT CONSIDERED z
1 3
4 NEW THERMAL LOADING 1
1 s
ERROR IN PREVIOUS PIPING/
4 z
1 1
8 SUPPORT CALCULATION 6
INCOMPLETE PREVIOUS SUPPORT 1
1 CAL.CULATION 7
INCOMPLETE PREVIOUS PIPING 1
1 2
ANALYSIS 8
AS-BUILT DISCREPANCY 2
1 1
4 PREVIOUSLY N~T EVALUATED 9
PREVIOUS CALCULATION NOT z
z 4
BASED ON LATEST LOADS 10 SAM PREVIOUSLY NOT I
2 3
CONSIDERED 11 DEFLECTION CHECK 1
1 PREVIOUSLY NOT CONSIDERED IZ CURRENJ CONFIGURATION 3
3 PREVIOUSLY NOT ANALYZED 13 LOCAL CHECK PREVIOUSLY NOT REQUIRED 1
1 PREVIOUSLY SPECIFIED HOD.
I 1
14 NOT INSTALLED IS UNIDENTIFIED SUPPORT
.1 1
NO. or OCCURENCES BY STRESS PACKAGE ZS 8
1 3.*
9 I
47 NO. or MODIFICATIONS 18 6
I z
9 1
37 CXHSR.ILS
Pal1sades Nuclear Plant SRPRP Phase llA/B Trend1ng Report EXHIBIT 6 - MATRIX
SUMMARY
OF ROOT CAUSE CATEGORIES flH6.lLS ITEM NO.
A D
E u
p ROOT CAUSE CATEGORY AS-BUILT DISCREPANCY DESIGN CRITERIA CHANGE ERROR IN PREVIOUS ANALYSIS SUPPORT CONFIGURATION PREVIOUSLY UNANALYZED BREAKDOWN IN DESIGN PROCESS NO. OF OCCURENCES BY STRESS PACKAGE NO. OF MODIFICATIONS
- 0 0
3 3
3 3
2
.2 0
5 3
ll
- 4 6
4 3
3 26 8
18
- 6.
0 3
3 8
2 0
3 3
8 3
0 3
3 8
4 STRESS PACKAGE 0
3 3
8 5
0 3
3 8
6 1
i 1
0 3
3 8
7 1
1 3
2 0
5 9
0 1
0 5
9 0
i 0
3 3*
1 2
1 s
1 2
9 9
0 3
3 1
3 l
Report No. SL-4848 0
NO. OF 3
OCCUR-3 ENCES BY 1
CATE~
6 GORY s
21 13 3
6 1
48 37 Re-v. 1.. '
Attachment C Consumers Power Company Palisades Plant Docket 50-255 LIST AND STATUS OF STRESS PACKAGES September 30, 1993
Phase I (Complete)
Stress Package SP02502+
SP02503+
SP03342 SP03356 SP03359 SP03360*
SP,03361 SP03362 SP03363 SP03364 SP03365 SP03366+
SP03367 SP03368+
SP03378 SP05101*
SP05102*
SP05903 SP05904 Attachment C List and Status of Stress Packages Long Term Cooling Long Term Cooling Aux Feedwater Discharge Aux Feedwater Pump Suction Pressurizer Surge Primary Loop Auxiliary Piping Pre~surizer Spray LPSI to Primary Loop IA LPSI to Primary Loop 18 LPSI to Primary Loop 2A LPSI to Primary Loop 28 HPSI to Primary Loop; Superseded.by SP 02503 HPSI to Primary Loop; Supersedes SP 06901 Redundant. HPSI; Sup~rseded by SP. 02502.
HPSI Piping Discharge Auxiliary Feedwater Piping to Steam Generator E-50A Auxiliary Feedwater Piping to Steam Generator E~508 Aux Feedwater Pump Suction Aux Feedwater Pump Discharge Reanalyzed with Phase 118 Stress Packages 1
+
SP03366 and SP03368 have been merged with SP02502 and SP02503 for final analysts.
Phase IIA (Complete)
Stress Package SP03320 SP03322 SP03325 SP03382 Safety Injection, Cont Spray and Shutdown Cooling Safety Injection, Cont Spray and Shutdown Cooling SFP Cooling.Pump Discharge to Spent Fuel Heat Exchangers Service Water From Eng Safeguard Cooler VHX-3
.Service Water to Eng Safeguard Cooler VHX-3 Servtce Water From Eng Safeguard Cooler VHX-4 Service Water to Eng Safeguard Cooler VHX-4 Service Water to Eng Safeguard Cooler VHX-2 2
. SP03383
'SP03384 SP03385*
SP03386 SP03387.
Service Water From Eng Safeguard Coolers VHX-1, VHX-2~ VHX-3 and VHX-'4
Stress Package SP03312 SP03313
. SP03316 Component Cooling Water Component *cooling Water Service Water From Eng Safeguards
3 Phase IIC - 20 stress packages (To be completed by the end of the 1995 Refueling Outage)
SP03311 SP03314 SP03315 SP03317 SP03318 SP03319 SP03340 SP03341 SP03369 SP03370 SP03371 SP03372 SP03373 SP03374.
SP03388 SP03389 SP05401 SP05402 SP05403 SP05404 Component Cooling Water Component Cooling Water Pumps Discharge Various Pump Sections Service Water to Eng Safeguards Service Water to Engineered Safeguards
(
Safety Injection*, Cont Spray and Shutdown Cooling Containment Sump Pumps.
Main Steam Containment Spray Containment Spray Main Feedw_ater 11A 11 Steam-Generator Main Feedwater 118 11 Steam Generator Main Steam Sy~tem Main Steam System
~pent Fuel Pool Cooling Reactor Cavity Drain and Recirc system Servi~e Water Return from Condensing Unit VC-10 Service Water Return to Condensing Unit VC-10 Service Water from Condensing Unit VC-11 Service Water to Condensing Unit VC-11 Phase IID - 26 stress*packages (To be completed by the end of the 1996 Refueling Outage)
SP03375 has been moved from Phase I to Phase IID