ML18065A172
| ML18065A172 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 10/17/1995 |
| From: | Smedley R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9510250054 | |
| Download: ML18065A172 (13) | |
Text
-*
consumers Power POWE RI Nii lllllCHlliAN'S PROliRESS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 October 17, 1995
() U S Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT SAFETY RELATED PIPING REVERIFICATION PROGRAM - PERIODIC STATUS -
SEPTEMBER 1995 The Safety Related Piping Reverification Program (SRPRP) was initiated to reverify the seismic design adequacy of large bore (> 2" nominal diameter) piping systems.
The sc~pe consists of physical walkdowns of accessible piping and pipe supports, performance of analysis for both piping and supports to current design criteria, and implementation of required modifications.
The purpose of this report is to summarize the recently completed Phase IIC of the pr:-ogram 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 in October of 1992.
The results of this portion of the program were transmitted to the NRC in a letter dated October 30, 1992.
Phases IIA and IIB consisted of reverification of 13 piping stress packages containing 271 pipe supports.
Phases IIA and IIB were completed in September of 1993.
The results of this portion of the program were transmitted to the NRC in a letter dated September 30, 1993.
Phase IIC of the program consisted of 21 piping stress ~ackages containing 755 pipe supports. Attachment A summarizes the Phase IIC scope.
Walkdowns for the Phase IIC effort were completed during the 1992 refueling outage in r~~~~:::::==:-:---=-=-:--~~~__:.__:_~-
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October of 1992. Analytical wotk and installation of required modifications were completed as plant conditions permitted.
The last Phase llC required modifications were completed during the 1995 refueling outage which ended in August 1995.
Phase 110 is the final phase of the SRPRP program and consists of the 25 p1p1ng stress packages in Attachment 8.
Walkdowns for all of the Phase 110 piping and pipe supports have been completed.
Results - Phase llC 2
The inspection of the 755 Phase llC piping supports and subsequent p1p1ng stress package reanalysi~, resulted in the completion of 94 pipe support modifications.
Eleven of the modifications were inside of containment, including 4 modifications on the containment spray system supports in the dome of the containment. Nearly all of the outside of containment modifications were completed prior to the start of the 1995 refueling outage, with all remaining modifications being completed during the refueling outage.
The exhibits provided in Attachment C summarize the reasons, root cause and root cause categories associated with Phase IJC modifications.
With the completion of Pha.se IIC, all of the SRPRP piping system analysis have shown that no piping system has exceeded. the interim operability crite~ia which were s.ubmitted to the NRC Staff in a letter dated November 22, 1989.
Trending At the completion of Phases l,llA, 118~ and llC, trending studies were performed and documented.
The results of these studies provide a basis for*
refocusing the requirements and processes of future program phases.
The majprity of Phase IIC modifications were due to design criteria changes (i.e., response to spectra peak broadening, use* of Regulatory Gui de 1. 60 spectra, lo~alized effects due to integral welded pipe at~achments to pipe, relative seismic-inovements between buildings,.. etc.) As-built discrepancies by themselves typically do not lead to modificatipns. These results are consistent wtth previous trending.
As an example of how the trending results were applied, based on the Phase I, IIA and 118 results, a refocusing of the walkdown process was implemented for Phase IIC.
The results of the first three phases showed that the majority of the modifications that were being implemented were due to updated piping design criteria that has been implemented concurrent with the field verifications. Since few of the modifications were based on as-built pipe support discrepancies, and based on our knowledge of those kinds of field conditions that were being identified as deficient, a revised walkdown process was implemented for Phase IIC which required less rigorous inspections of selected pipe support attributes. Specifically, requirements for precise readings of spring hanger load indicators and exact measurements of support
3 member lengths, weld sizes, and gaps were replaced with visual inspection criteria. With these changes the Phase llC trending results for modifications remained consistent with the first three phase results indicating that the revised inspection criteria continued to be focused on the critical hanger deficient areas.
On this basis, the Phase llD walkdowns were performed with the same criteria used in Phase llC.
Likewise, current requirements for pipe support inspection for missing and loose fasteners have continued as required per the Pipe Support Preventative Maintenance Program.
Since our trending results continue to show that most of the modifications are the result of design criterh changes and we have always met the interim operability requirements, we are assured that the remaining piping systems will not require any major modifications.
Future Pro.aram Direction Walkdown data for all of the Phase llD systems has been collected.
No major discrepancies between as-butlt and as-designed condition for any of these piping systems have been identified. These conditions coupled with the lack of safety related functional significance of many rif the final Phase 11D piping systems.suggest a priority for completion which can accommodate an extension to the current schedule.
Our initial project completion schedule was transmitted to the NRC in a letter dated December 21, 1991.
The SRPRP program was shown to be completed by the end of 1996.
Since 1) nG major concerns have been identified from the Phase 110 walkdown data; 2) no pipe support or system deficiency discovered to date have affected the piping system such that it would exceed the interim operating criteria; 3) the remainiflg systems to be reverified for design adequacy are of a somewhat lesser importance relative to safety significance; and 4) the potential safety enhancement provided by thi S* portion of the SRPRP is less than other more significant plant enhancements in competi_tion for these sam~ resoun:es, this.
final phase of the SRPRP Project will be completed by the end of 1998.
This extension to the scheduled completion of the SRPRP will have no adverse affect on the safety related operation of the plant.
We will continue to submit SRPRP status reports following each refueling outage until we have completed our planned actions.
SUMMARY
OF COMMITMENTS This letter contains no new commitments and two revisions to existing commitments.
I.
The final Phase of the SRPRP project will be completed by the end of 1998.
- 2.
We will continue to submit SRPRP status reports following each refueling outage until we have completed our planned ~ctions.
~~,t\\V~ir Richard W Smedley Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR~ USNRC NRC Resident Inspector - Palisades Attachment 4
ATIACHMENT A CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 SAFETY RELATED PIPING REVERIFICATION PROGRAM PHASE IIC SCOPE 1 Page
STRESS PACKAGE 03311 03314 03315 03317 03318 03319 03340 03341 03369 03370 03371 03372 03373 03374 03375 03388 03389 05401 05402 05403 05404 I
21 ATTACHMENT A PHASE llC SCOPE
SUMMARY
~- ~
SYSTEM Component Cooling Water Component Cooling Water Component Cooling Water Service Water to Engineered Safeguards Service Water to Engineered Safeguards Safety lnjec.tion, Shutdown Cooling and Cont. Spray Containment Sump Pumps Main Steam Containment Spray Containment Spray Main Feedwater Main Feedwater Main Steam Main Steam Pressurizer Relief Valve Discharge Piping Spent Fuel Pool Cooling Reactor Cavity Drain & Recirc. System Service Water Service Water Service Water Service Water Stress Packages
- Inside/Outside Containment Page 1 of 1 NO.OF 1/0~
SUPPORTS 0
46 0
44 0
81 0
109 0
53 0
96 0
9 0
28 I
102 I
102 I
8 I
8 I
4 I
4 I
36 I
8 I
4 0
3 0
2 0
4 0
4 Supports :
7551
ATTACHMENT B CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 SAFETY REJ,.ATED PIPING REVERIFICATION PROGRAM PHASE 110 SCOPE 1 Page
STRESS PACKAGE 03323 03324 03326 03327 03328 03329 03330 03331 03332 03339 03345 03347 03351 03353 03354 03355 03357 03358 03377 03379 03381 03390 07015 07016 07017 I
25 ATTACHMENT B PHASE llD SCOPE
SUMMARY
SYSTEM (all Outside Containment)
Boric Acid Pump Suction Spent Fuel Pool Cooling SIRW Tank Recirculating Piping Makeup Water Makeup Demin Inlet to T-2 Clean Waste Recirc Tank P-70 Discharge Clean Waste Recirc Tank P-70 Suction Misc Condensate Inlet Condensate Makeup and Reject Vacuum Pump Tank C-51 to Waste Gas Surge Tank Drain Tank Pump Suction - P-71A and B Radwaste Treatment System Clean Waste Receiver Tank Pump Suction Containment Purge Exhaust Containment Purge Supply Air Space Purge Fan Plant Steam Heating System Main Steam Line Atmospheric Relief Charging Pumps Suction Feedwater to E-6A Spent Fuel Pool Heat Exchanger Cross Tee Piping SIRWTank T-58 Fill Line ILRT Fill Line Diesel Fuel Oil Condensate Reject Stress Packages Page 1 of 1 NO.OF SUPPORTS 82 48
. 16 10 0
9 2
2 20 5
8 4
7 4
1 2
3 81 34 23 0
19 25 11 14 Supports :
430 I
ATTACHMENT C CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 SAFETY RELATED PIPING REVERIFICATION PROGRAM PHASE llC MODIFICATIONS 4 Pages
ATIACHMENT C PHASE IIC MODIFICATION CATEGORIZATION/CRITERIA MODIFICATION CATEGORY
- 1. Major Modification A. New support B. Modify existing support C.Removal
- 2. Minor Modification A.Replace bolted component B.Pinning spring can C.Increase weld size
- 3. Non-SRPRP Modification A.Lead shielding CRITERIA Work involves welding, new members, Cutting/grinding involved.
No welding/cutting involved.
Convert spring to rod hanger.
No other work involved.
anchor bolts, etc.
B.SWS valve replacement project Mod required to accommodate permanent lead shielding.
Mod due to interference problem with new valve.
- 4. Maintenance Item A.Shimming B.Spring can resetting 5.Support Removal Within MSM-M-45 criteria.
No other work involved.
No cutting or grinding. Removal avoids major mod.
7.Non:-Modification (Abandon in place)
No physical work required. Not part of SC.
ATIACHMENT C PHASE IIC MODIFICATION
SUMMARY
Number of Modifications Modification Category Subtotal Total
- 1.
Major Modification 69 A. New support 16 B. Modify existing support 49
)
C. Removal 4
- 2.
Minor Modification 5
A. Replace bolted component 3
B. Pinning spring can 1
C. Increase weld size 1
- 3.
Non-SRPRP Modification 2
A. Lead shielding 1
- B. SWS Valve Replacement Project ___
1
- 4.
Maintenance Item 0
A. Shimming 0
B. Spring can resetting 0
- 5.
Support Removal 13
- 6.
Snubber Removal/Replacement 5
TOTAL 94
- 7.
Non-Modification (Abandon: in Place) 25
Palisades Nuclear Plant SRPRP Phase llC ATIACBMENTC MATRIX
SUMMARY
OF.l\\fODIFICATION ROOT CAUSES I
STRESS PACKAGE 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
3 3
3 3
3 3
3 3
3 3
3 3
3 3
3 ITEM ROOTCAUSE
- 3 3
3 3
3 3 ; 3 3
3 3
3 3
3 3
3 NO.
I I
I I
I I
4 4
6 7
7 7
7 7
7 I
4 5
7 8
9' 0 1
9 0
I 2
3 4
5 I
REVISED SEISMIC CRITERIA 3
6 5
- 14.
3 IW M PREVIOUSLY NOT CONSIDERED I
I 4
NEW TIIERMAL LOADING 2
6 5
ERROR IN PREVIOUS PIPINO/
2 1
5, 2
SUPPORT CALCULATION AS-BUILT DISCREPANCY 8
PREVIOUSLY NOT EVALUATED 4
2 1
10 SAM PREVIOUSLY NOT 3
I 5
7, I
2 I
I CONSIDERED II DEFLECTION CHECK 2
I PREVIOUSLY NOT CONSIDERED 12 CURRENT CONFIGURATION I
I*
I PREVIOUSLY NOT ANALYZED 15 UNIDEN11FIED SUPPORT I
16 EQUIPMENT NOZZLE LOADING 4
PREVIOUSLY NOT CONSIDERED 17 POOR SUPPORT DESIGN 2
3 2
I I
I 18 GANG SUPPORT
- I 3
2 19 SNUBBER REDUCTION s
NO. OF OCCURENCES BY STRESS PACKAGE 13 I
3 20 8
49 I
2 4
I 1
3 NO. OF MODIFICATIONS 12 I
3 15 8
41 I
2 4
I I
2 EXHJCN.XLS 0
0 6
0 0
0 NO:OF 3
3 5
5 5
5 OCCUR-3 3
4 4
4 4
t:NCES 8
8 0
0 0
0
~y llOOT 8
9 I
2 3
4 CAIJSE 1
1 30 2
8 I
11 7
21 2
3 I
4
- e.
9 6
s 2
I 109 2
I 94
Palisades Nuclear Plant SRPRP Phase llC AITACHMENTC MATRIX
SUMMARY
OF ROOT CAUSE CATEGORIES STRESS PACK.AGE
~ -
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 3
3 3
3 3
l 3
3 3
3 3
3 3
3 3
ffEM ROOTCAUSECA~~y 3
3 3
3 3
3 3
3 3
3 3
3 3
3 3
NO.
I I
I I
I I
I*
4 4
6 7
7 7
7 7
7 I
4 5
7 8
9 0
I 9
0 I
2
~
4 5
A AS-BUILT DISCREPANCY s
2 I
D DESIGN CRITERIA CHANGE 7
I IS 6
31 I
2 I
I E
ERROR IN PREVIOUS ANALYSIS/
6 3
s 2
8 2
2 DESIGN PROCESS DISCREPANCIES s
DISCRETIONARY MODIFICATION s
~
(SNUBBERS)
NO. OFOCCURENCES BY STRESS PACKAGE 13.
I 3
20 8
49 I
2 4
I I
3 NO. OF MODIFICATIONS 12 I
3 IS 8
41 I
2 4
I I
2 EXH4CN.XLS
- O 0
0 0
0 0. NO.OF 3
3 5
5 5
5 oc;cuR-3 3
4 4
4 4
8 0
0 0
0 CATE-8 9
I 2
3 4
OORY 8
I I
67 I
29 s
2 I
109 2
I 94