ML20062C076
| ML20062C076 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 07/19/1982 |
| From: | Morisi A BOSTON EDISON CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| REF-SSINS-6820 82-195, IEB-79-02, IEB-79-14, IEB-79-2, NUDOCS 8208050162 | |
| Download: ML20062C076 (32) | |
Text
e 4
BOSTON EDl5DN COMPANY GENE AAL OFFICEE 500 BOYLSTON STREEr BOSTON, Mag eACHUE ETTs 0 219 9 A. V. M O RISI MANAGER NUCLEAR OPERATIONS SUPPORT DEPARTMENT July 19,1982 BECo. Ltr. # 82-195 1
Ronald C. Haynes Office of Inspection and Enforcement Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA License No. DPR-35 Docket No. 50-293 NRC IE BULLETIN 79-02 and IE BULLETIN 79-14 FINAL REPORT
Dear Sir:
In accordance with the requirements of the NRC IE Bulletin 79-14 and its revisions and supplements, Boston Edison Company (BECo.) performed an inspection and re-evaluation of the "As-Blilt" configuration of the Safety Related Piping Systems at the Pilgrim Nuclear Power Station.
During this period BECo. was also in the process of addressing the NRC IE Bulletin 79-02, its revisions and supplements.
IEB 79-02 required an "As-Built" configuration inspection and reanalysis of the safety related pipe support base plates which utilized concrete expansion anchor bolts.
l It was evident that the results of the IEB 79-14 inspections and re-evaluation would play an important role in BECo's final disposition of the IEB 79-02 requirements.
Conversely, the results of the IEB 79-02 inspections, testing programs, and modifications would impact on the. resolution of the IEB 79-14 requi rements.
Due to the fact that the inputs and results of the two bulletins were inter-dependent, BECo believes it appropriate to provide the final responses for the two bulletins in one concise report.
Therefore, the findings, procedures, criteria, and final results of IE Bulletin 79-02 and 79-14 are provided in one report. This report is intended to be used in conjunction with, and as a supplement to, our previous responses to the subject bulletins.
Please note that there are four (4) support modifications awaiting implementation.
They are as follows:
(1) H-29-1-9SG (79-02 Fix) Salt Service Water System Fix: Addition of washers to correct oversized bolt holes in base plate 8208050162 820719 l
PDR ADOCK 05000293 j
G PDR g,0
CO3 TON EDCON COMPANY Mr. Ronald C. Haynes July 19,1982 Page 2 (2) H-30-1-286 (79-14 Fix)RBCCW System Fix: Addition of bracing member with base plate.
(3) H-30-1-92 (79-14 Fix)RBCCW and TBCCW Systems Fix:
Increase weld sizes and add a bracing member.
(4) H-30-1-376 (79-14 Fix)RBCCW System Fix:
Increase weld sizes These modifications are minor in nature and system operability is not effected.
BECo. expects these modifications to be completed in late 1982 and will notify the NRC upon completion.
Should you require any additional information concerning this report, please do not hesitate to contact us.
Very truly yours,
[
1 NRC IE BULIETIN 79-14 and 79-02 PIIERIM NUCIEM POER STATIQ1 UNIT 1 FINAL REPORT PREPARED BY BOSTON EDISai JUNE 1982
~
CCtllEETS i
Section Page 1
INTRODUCTION
.1-1 2
TASK ACTIVITIES AND WORK FILM 2-1 3
PROCEDURES AND CRITERIA 3-1 3.1 IEB 79-14 3.1.1 Piping System Inspection Procedure '
3.1.2 Deviation Dispositicm 3.1.3 Evaluation of Input Documents 3.1.4 Piping Analysis Procedure and Criteria l
3.1.5 Pipe Support Analysis Procedure and Criteria 3.1.6 Large Canposite Pipe Support Review Criteria 3.1.7 Equipnent Nozzle Ioad Review Procedure 3.1.8 Effect of IE Bulletin 79-14 Reanalysis on Pipe Break Outside Containment Analysis i
3.1.9 Consideration of Friction Ioad -
3.1.10 Review of CRD Scram Discharge Volumes and -
Small Piping 3.1.11 Review for IE Bullitin 79-02 Concerns, Including Maso w Wall-Mounted Supports 3.2 IEB 79-02 3-12 3.2.1 Base Plate And Anchor Bolt Inspection Procedure 3.2.2 Descrepency Disposition 3.2.3 Base Plate Analysis Procedure and Criteria 3.2.4 Review and Analysis of Base Plates 4.
REVIEW AND ANALYSIS RESULTS 4-1 5
DOCUMErfrATION 5-1 e.
e
--n...--.-
...w-,,
-n
ILLUSTRATIONS Fig ure Page 2-1 Activities During Plant Operation 2-2 2-2 Activities During Refueling Outage and 2-3 Final Documentation 3-1 Weight Analysis-Consideration of Springs 3-2 Calculation Sheet 3-3 Pipe Support Symbols 3,4 Equipment Nozzle Review Force / Moment Diagram 5-1 As-Built Deviation Disposition Form 5-2 b
=
5 4
SECTIO 3 X IN'IROD(.UTION
'Ihe Nuclear Regulatory Camission (NRC) IE Bulletin 79-]4 required verification that seismic analyses performed for safety related piping in nuclear power plants reflect the actual configuration of the installed systens. The NBC IE Bulletin 79-02 required an inspection and reanalysis of pipe support base plates and concrete ex-pansion anchor bolts which were utilized on Seisnic Category I systens.
In order to respond to these requirenents for the Pilgrim Nuclear Power Station, Unit 1, Boston Edison has contracted major engineering firms such as Bechtel Power Corporation and Teledyne Engineering Services and established the following general scope work.
1.1 BBCIrrEL WORK SCOPE Review of all Seismic Category I lines identified by Boston Edison of IE Bulletin 79-14 requirements.
Review the design documents against input parameters used in the original seisnic analyses of piping systens. Identify all deviations encountered during this review.
Assist in the field inspection of the Seismic Category I piping systens.
Review the as-built deviations (both input and as-built) from the design documentation identified during field inspection of piping and supports.
Evaluate the impact of all the deviations on the operability of the piping systans. Bechtel provided stress engineers to provide an initial evaluation of the inspection and input deviations.
Perform any required analyses and determine what modifications, if any, are needed to restore piping and support stresses to within code allowable limits.
Assist in expediting the modification effort by establishing a support design team at the job site.
Perform reviews and analyses, as required, to determine whether or ~not piping systens should be considered operable.
Provide Boston Edison with pipe support loads for the analyses of base-plate and concrete expansion bolts required by IE Bulletin 79-02.
Provide input to Boston Edison's initial and final reports to NPC.
1-1
=
1.2 'IEIEDYNE WORK SCOPE The experimental develognent of Shear-tension interaction curves to properly apply the specified bulletin safety factor for otrabined loading.
Experimental determination of the adequacy of conrete anchor bolts that are not preloaded to withstand cycle loading.
An analytical technique for detennining the effect of base plate flexibilty 1
on concrete anchor bolt loading.
1.3 BC6'IO1 EDISON WORK SCOPE Identify all seismic Category I lines that are subject to IE Bulletin 79-]4 requironents.
Prepare the piping and pipe support field inspection procedure.
Initiate and coordinate the piping ard pipe support field inspection.
Identify pipe supports using concrete expansion bolts in seismic category I piping systons subject to IE Bulltein 79-02 requirunents.
Inspect and analyze pipe support baseplates and concrete expansion bolts as required by IE Bulletin 79-02, excluding supports modified under the IE Bulletin 79-]4 effort (Bechtel's Scope).
1 Directed and reviewed IE Bulletin 79-02 generic program perfonned by Telcdyne Engineering Serivce for the utility omer's group.
Directcd and coordinated engineerirg efforts of consultants.
1 Install all required modifications.
l Report findings and corrective actions to the NRC.
e 1
i 1-2
.y
. ywrw
-.,e w
5+.,my--
i p-
.m.w-m-.
y.
,,sw,,_._.r.., -. _ _.,y.w--4_y.,,-v,,,-,---
m.
i.._.ge,,
SECTION 2 TASK ACTIVITIES AND WORK FIIM Figures 2-1 and 2-2 identify the activities and responsibilities of the field and office groups involved in the verification and reanalysis effort. Figure 2-1 shows activities carried out during plant operation and Figure 2-2 shows activities carried out during the refueling outage and the final documentation effort.
The primary objective during plant operation was to determine the operability of accessible piping systms, supports, and base plates under design and maximum earthquake loads. Therefore, only thase supports or base plates which affected operability were modified at this time. During the refueling outage, the r m aining supports and base plates that required modification were identified and design changes were prepared to restore the piping stresses, pipe support and base plate l
stresses, and bolt loads to within the code-allowable limits.
2.1 ACTIVITIES DURING PLANT OPERATICN All accessible systans and base plates were inspected during plant operation prior to the refueling outage. All systan and pipe support related non-conformances were documented on 79-14 deviation reports. All base plate and concrete expansion anchor If an bolt related non-conformances were documented on 79-02 discrepency reports..
unacceptable 79-14 non-conformance (deviation) was identified, a piping stress analysis was performed to deternine system operability (see Figure 2-]). Pipe support reviews were then performed using the newly calculated loads. If one or more supports were found inoperable during the review, the inoperable support (s) was renoved fran the analysis model and a reanalysis was performed. This reiterative cycle of analysis and review was carried out until syston operability was denonstrated or the systen was determined to be inoperable.
If an unacceptable 79-02 non-conformance (discrepency) was identified, a base plate and anchor bolt load analysis was performed to determine operability. An operability safety factor of 1.25, detailed in BECo's letter to the NRC dated 10/15/79 was used i
in the base plate / anchor bolt review process.
If one or more anchor bolts were found inoperable during the review, the associated support (s) was renoved fran the piping analysis rrodel and syston operability was verified as detailed above.
I 2.2 ACTIVITIES DURING REFUELING OUTAGE I
Systans, portions of systans, pipe supports, and base plates which were inaccessible during plant operation were inspected and, if required, modified during this period.
In addition, any piping systans declared inoperable were restored to operability limits l.
as a minimum.
l I
l i
i 2-1
REwEW a COMPARE DESIGri INS >ECTION OF ACCESSIBLE DOCUMEr.TS AG AINST INPUT SYST El?.S PARAMETERS FOR ALL SYS.
(OFF(CE)
(FIE LD)
+
+
ASSESS'/ENT OF DEVIATIONS ON THE ORIGINAL PlPING ANALYSIS (OFFICE / FIELD)
E -- -
a REANALYSIS OF SYSTEM ISO *AETRICS ARE SYSTEM DEVIATIONS
~ ~ _ _, _ _ _
, PP.EPARE A SUPPORT LOAD TABLE 4
SIGNIFIC. ANT OR M/JOR?
FOR PIPE SUPPORT ANALYSIS (OFFICE)
YES NO 9
r COMFARISION OF NEWLY ARE PIPING STRESSES CALCULATED LOADS W{ THIN OPERABILITY Q
AGAINST THOSE USED IN r
. LIMITS ?
YES THE ORIGINAL DESIGN.
(OFFICE) y I
NO ARE NEW LOADS LOWER 7 i
l fYES l
NO PAPE SUPPORT REVIEW NO FURTHER REVIEW USING NEW GENERATED IS REQUIRED AT THIS POINT
$ LOADS AND ANY FURTHER EVALUATION TO APPLICABLE DEVIATIONS BE PERFORMED AS SHOWN (SFPD)
IN FIG. 2 2 1
l
{
p l
See (B) 4 See (A) 1 r Figure 2 2 Figure 2 YES IS SUPPORT OPERABLE?
l NO INOPERABLE SUPPORTS FROM FIG.2 2
+*
l INITIATE A MODIFICATION See (C)
FOR THE INOPERABLE muss Figure 2-2 h
SUPPORT (S)
(OFFICE) p PERFORM A PIPING OPERABILITY ANALYSIS VERIFY FEASIBILITY OF EXCLUDING THE INOPERABLE THE,NEW MODIFICATION SUPPORT (S) FROM THE o g, gg
.d h (FIELD)
ANALYSIS MODEL (OFFICE) p gg 4
4 FINALIZE SUPPORT YES ARE PlPlNG STRESSES DESIGN ammu WITHIN OPERABILITY' (OF FICE/FIE LD)
I LIMITS?
I NO ISSUE SUPPORT MODIF.
DRWG. FOR CONSTRUCTION j
SYSTEM TO BE DECLARED g
INOPER ABLE. SUPPORT I
MOOlFICATION MUST BE
' P COMPLETED WITH TECH PEC LIMITS GENER ATE NEW SUPPORT e
LOAD TABLES l
(OFFICE)
FIGURE 2-1 ACTIVITIES DUR!!!G PLA??T OPERATION
INSFZ~ TION OF IN ACCESSIBLE SYSTEMS (FIE LD)
+
ASSESSMENT OF DEVIATIONS AND THEIR, EFFECT ON.
ORIGINAL PIPING AN ALYSIS (CIELD SFHO)
YES i
NO ARE SYSTEM DEVIATIONS SIGNIFICANT OR MAJOR?
RE AN ALYSIS OF SYSTEM ISOMETRICS.
SUPPORT LOAD TABLES BASED l
PREPARE A SUPPORT LOAD TABLE ON ORIGINAL LOADS WERE 2
FOR PIPE SUPPORT ANALYSIS GENERATED See (A) Figure 21 (OFFICE)
(OFFICE)
+
REVIEW AND REANALYSIS OF SUPPORTS INCLUDING ANY 4 APPLICABLE DEVIATIONS (OFFICE)
See (B) Figure 21
+<
4 YES ARE SUPPORT STRESSES SUPPORTS FROM 2
WITHIN CODE ALLOWABLE FIG. 21 9
l LIMITS)
Q NO s
IS PLANT h
i IS SUPPORT T
OPERATING?
3 i
OPERABLE 7 y
hYES NO c
YES NO j
CONTINUE ACTIVITIES 2nd In AS SHOWN IN Z
PRIORITY PRIORITY FIG. 2.1 6
N O E
N 2 k
W See (C) Fsgure 21 c: e r
DESIGN A SUPPORT D z i
MODIFICATION 93 (OFFICE)
'g e
m VERIFY THE DESIGN l
(OFFICE) e t
z FINAll2E THE DESIGN (OFFICE) o M
E ISSUE SUPPORT MODIF! CATION b
s DR AWING FOR CONSTRUCTION g
/
p k
DOCUMENTATION OF CALCULATION
- 8. DESIGN DWGS.
i INCLUDING AS-r BUILT LNFORMATION (OFFICE)
SECTION 3 PRCCEDURES AND CRITERIA 3.1 IS liULIEPIN 79-14 The inspection and analysis procedures and criteria uied ' d uring the seismic analysis verification effort in compliance with IE Bulletin 79-14 are described below.
3.1.1 PIPP7; SYSTEM INSPFUTICN PROCEDURE A piping system field inspection program was established to satisfy the IE Bulletin 79-14 requirements.
Boston Edison pro-cedure No.
TP79-21 provides details of the inspection procedure, acceptance criteria, and method of documentation.
3.1.2 DEVIATION DISPOSITION Deviations identified during plant operation were assessed immediately based on engineering judgment.
The intent of this assessment was to evaluate the impact of the deviations on the operability of the systems.
If appropriate, a piping stress analysis was performed promptly to confirm the validity of the initial judgment.
3.1.3 LVALUATION OF INPUT DOCHEVIS The input parameters to the original piping analysis were compared with the design document information.
Any discrepancies in the input were identified and their irrpa ct on the original piping analysis was evaluated by engineering judgment.
A computer stress analysis was per formed as necessary to confirm the validity of such judgment.
The design documents used for this evaluation were:
piping as-built isometr.ics piping area drawings piping class sheets piping line ' list vendor drawings for valves 3.1.4 PIPING ANALYSIS PROCEDURE A'O CRITERIA This procedure provided the criteria for reanalysis of seismic Category I piping in compliance with the requirements of NRC IE Bulletin 79-14 dated July 2,1979 and the Bechtel generic program.
3.1.4.1 CODES, STANDARDS, AND OTHER REFERENCES a.
USAS B31.1.0 - 1967 code is the piping code applicable to Pilgrim Unit 'l; however, ANSI B 31.1 - 19 73 edition was also utilized in some stress analysis activities.
Justification for use of the 1973 edition is contained in subsection 3.1.4.8.
3-1
b.
The Final Safety Analysis Report (FSAR) for Pilgrim Nuclear Power Station, Unit 1.
3.1.4.2 TYPES OF ANALYSES The following analyses were perforrred as appropriate k>n systems where differences between the as-built and as-analyzed condition were j udged significant.
3.1.4.2.1 Seismic Analysis Seismic Analysis Approach 9
A dynamic response spectra analysis for the operating basis earth-quake (OBE, design earthquake) was performed using Bechtel computer program ME101.
Two analyses considering the simultaneous occur-rence of X
+Y or Z + Y excitations as specified in the FSAR were performed.
Results were combined by the SRSS method for each earthquake analysis.
Reported output parameters were based on the. maximum of X +Y or Y + 2 earthquakes.
Other pertinent analysis methodology were in accordance with the original analy-sis and the FSAR.
The OBE analysis responses (displacement, loads, stresses, etc) were multiplied by 1.875 in order to obtain safe shutdown earthquake (SSE, maximum credible earthquake) res-ponses.
This approach is conservative since it does not take credit for higher damping values allowed for SSE.
Modeling Aspects In general, the original modeling techniques were used in the re-analysis model.
However, the following specific modeling tech-niques were incorporated where appropriate.
Components with concentrated masses
- Concentrated Masses such as valves, valve operators, flanges, etc., were modeled considering their total weight to act at the center of gravity of the componst n t.
components with a center of gravity that ccoincided with the pipe center were modeled either as a concentrated or a uniformly distributed load.
Modeling of Tee Connections - Where the ratio of the diameter of the run pipe to that of the branch pipe was equal to or larger than 3, the branch was analyzed independently, assuming an analytical anchor at the connection to the main piping.
The appropriate stress intensification factor for tee con-nections was considered.
6 e
3-2
Response Spectra Pesponse spectra curves used in the reanalysis were, based on the input to the original analysis.
(See paragraph 12.2.3.5.2 of FSAR).
The response spectra for each calculation was, chosen as the average between the highest and lowest points in the calcula-tion.
This method of averaging is consistent with that used in the original analysis.
The appropriate issue of response spectra curves that were applicable to the piping analysis were verified in accordance with IE Information Notice 79-31.
3.1.4.2.2 Weight Analysis A weight analysis was performa4 where necessary, using the Bechtel ME101 computer program.
Actual spring hanger loads and spring rates provided by the field were used in the analysis.
(See Figure 3-1 for additional details).
3.1.4.2.3
'Ihermal Analysis A thermal expansion analysis was performed where necessary, using the ME101 computer program.
The maximum operating temperature of the system was used in this analysis.
-For piping systems that experience more than one mode of operation, the analysis was performed based on the mode with the most severe operating condition.
This analysis was not considered to be required by IE Bulletin 79-14, but was performed for completeness and to f acilitate the pipe support review.
3.1.4.3 IDADING OIDITIONS AND STRESS LIMITS The loading conditions and stress limits were as fo7 lows:
Loading Conditions Stress Units Normal condiN on*
SLP + SW < Sh Upset condition
- SOBF + SLP + SW <_ l.2Sh SSSF+SLP+SW<S(4S Faulted condition *
+ SLP + SW 5 2 h
System operability **
ccce See paragraph A 3.1.1.1 of FSAR Based on faulted allowables for ASME Section III class 2 piping rules.
m e
3-3
Where SLP'
= Longitudinal pressure stress SW
= Gravity stress SOBE
= Design earthquake stress SSSE
= Maximum credible earthquake stress Sh
= Allowable stress from the code (B31.1 1967 edition)
S
= Yield stress y
Valve Acceleration Limits For valves with extended mass, the allowable acceleration in faulted condition was 3.09 3.1.4.4 PIPING STRESS AND SUPPORT IDAD SUR1ARY The results of the analysis were summarized in the forms shown in Figure 3-2.
3.1.4.5 STRESS IITTENSIFICATION FACIOR (SIF)
SIFs from USAS B31.1.0-1967 piping code were used for elbows, tees, e tc.
3.1.4.6 PIPE SUPPORT TYPE The notations for each type of pipe support and restraint utilized in the stress analysis isometrics is in Figure 3-3.
3.1.4.7 REVIEN AND APPROVAL OF ANALYSIS Each analysis was reviewed by a stress analysis engineer, qualified to performed the analysis independently.
The analysis was approved by the Stress Group Supervisor or his designee.
3.1.4.8 JUSTIFICATIOJ EUR USE OF ANSI B31.1-1973 CODE EDITION WITH SLRBER 1973 ADDENDA The 1973 Code corrected a long standing improper application of stress intensifications factors (SIFs) to moments producing pri-mary stresses.
The use of the following stress term in code equations 11, 12 and l*4 has corrected that:
0.751 g/ M2
+
M2
+
M2
,z V
x y
z 3.-
4
Per USAS B31 1.0 1967 Code foreword, the designed is free to use a less conservative design provided it can be justified that it still satisfies the basic intent of Code.
The pertinent section of the foreword reads as follows:
"The Code never intentionally puts a ceiling on 'conser-vatism.
A designer is free to specify more rigid require-ments as he feels they may be j ustified.
Conversely, a designer who is capable of a more rigorous analysis than is specified in the Code may justifv a less conservative design, and still satisfy the basic intent of the Code."
The analyses performed in response to IE Bulletin 79-14 were more rigorous to satisfy equations 11, 12, 13, and 14 of the Code.
Also, stress intensification factors based on B31.1, 1973 Code were considered for additional components not mentioned in the 1967 Code.
3.1.5 PIPE SUPPORTS ANALYSIS PROCEDURE AND CRITERIA The criteria for pipe support analysis encompasses the following proced ure s :
Review and analysis of seismic Category I pipe supports.
Review of seismic Category I pipe anchors including those at the boundary between seismic and non-seismic Category I lines.
Review of interface welds between piping and integral
~
pipe attachments.
These procedures are described in the following subsections.
l 3.1.5.1 REVIIM AND ANALYSIS OF PIPE SUPPORTS The Boston Edison /Bechtel inspection team at the jobsite inspected seismic Category
,T, piping systems and their associated pipe supports, and compared as-built conditions with design drawings.
Identified discrepancies which exceeded tolerances set by Boston Edison inspection procedure number TP 79-21 were documented on as-built deviation forms.
As-built deviations were then distributed to engineering for resolution.
The pipe stress engineering group at the Bechtel home office reviewed the ef fect of as-built deviations on the original piping analysis and determined whether reanalysis was warranted.
Revised pipe support load tables were issued to Boston Edison for IE Bulletin 79-02 review if piping reanalysis was required..
9 3-5
Analysis of pip 2 supports mounted on msonry walls showed that t shosed that their failure would not render the piping system inoperable.
Wherever feasible, pipe supports attached to bicck walls were redesigned and re uved Khere re:roval was not feasible, there will be followfup action in from block walls.
accordance with IE Bulletin 80-11, as required.
3.1.5.1.1 Codes, Standards and Otter Feferences Systems and pipe supports were reviewed in accordance with either the ANSI B31.1 Code or the AISC Code.
Ooerating Revised stress levels were reviewed against three sets of allowables:
Allowable basis earthquake (OBE); Safe Shutdown Earthquake (SSE); and Operability.
stresscd for OBE and SSE load combinations are based on FSAR criteria or original design practices; operability allowables are similar to current values given in subsection NF of the ASSE Code.
[
3.1.5.1.2 Pioe Sucoort Modification Desian Sequence When the review process identified a pipe support, with stresses exceeding code allowables, a modification was designed to restoredesign those allowables.
These modifications were issued as drawing s.
Boston Edison provided information regarding design modifications made by them in response to IE Bulletin 79-02, which was then reviewed and coordinated with the IE Bulletin 79-14 portion of Bechtel's work.
The following considerations were used to assign a higher priority to the completion of the design modification process:
Pipe support modification designs with long material lead time.
Pipe supports located in areas that would be con-sidered inaccessible during plant startup and s
operation.
installation of the moAiFications, Boston Edison trans-mitted updated as-built sketches to the Bechtel home
- office, Following were updated and transmitted detail drawings where the original Bechtel also updated corresponding design back to Boston Edison.
calculations of modified pipe supports for transmittal to Boston Edison.
As a part of the final documentation, the Bechtel home office updated the review calculations of pipe supports which were ade-quate without modifications to agree with the latest issue of the pipe support load tables and transmitted a copy to Boston Ed i son.
3-6
3.1.5.2 REVIDi OF PIPE A JCHORS 7here are six load ccmponents at the pipe anchor for each dead load, thermal, design earthquake, and maxir.um earthquake condition. The anchor loads were combined conservatively in accordance with load ccrnbinaticos listed in Design Criteria for Anchors. For boundary anchors, loads were strrations of the seismic Category I piping anchor loads from one side and the nonseismic Category I piping anchor loads frcm the other. If the non seismic Category I piping anchor loads were not available, total anchor loads were taken as twice the Category I piping anchor loads.
Load combinations resulting in the maximum value were utilized to calculate stresses in anchor to piping welds in the anchor structure, as well as in the intermediate support members using verified analytical methods and documented computer programs.
Original data given in design drawings and all as-built field deviations obtained during the field inspection survey were incorporated in this review.
Allowable stresses for anchor to piping welds, anchor structures, and intermediate support members are given in Appendix B.
Modi-fications were made as necessary to restore code allowable stresses.
Detail drawings were prepared for the modified pipe anchors.
No formal operability criteria documentation was issued for pipe anchors, however, engineering judgment was applied to determine acceptability for operation based on related operability criteria fc,r pipe supports.
A final as-built sketch was issued by Boston Edison to identify field revisions to the modified design drawings.
Acceptability
'of the revisions was documented in the final calculations.
Upon completion of the modifications, associated field revisions were incorporated in the final modification drawings.
3.1.5.3 PIPE AND ANCHOR ATf/CHMENTS Anchor stresses were evaluated up to and including the interface weld between the pipe and the anchor structure.
If the attachment stresses were within the code allowables, no local piping stress i
l analysis was performed.
If, however, the attachment stress ex-l ceeded the code allowables, local piping stress analysis was performed at the interface to determine if the stresses in the pipe were within acceptable limits.
Local piping stresses were calculated, either by using stress l
intensification factors of ANSI B31.1 for stanchion type anchors, l
or by using Bechtel computer program ME210, which is based on the Welding Research Council analysis method (Bulletin 107).
3.1.6 IARGE COMPOSITE PIPE SUPPORT REVISV PROCEDURE A composite pipe support is a structure ' commonly supporting two or more seismic Category I and/or non seismic Category I pipes, and, in some instances, cond uit.
Twenty-one large steel frame composite support structures in the auxiliary building were reviewed based on the following methods and assumptions.
3-7
3.1.6.1 ASSleFTIONS Loads for conduits were assumed to be the same as for a similar size of pipe.
The analysis was performed assuming that all loads would act in the same direction simultaneously.
This assumption was made to simplify the analysis since, with twenty. pipes in one frame, an excesssive number of load combinations would have.had to be reviewed.
3.1.6.2 INSPECTION AND ANALYSIS The following were used in the knalysis:
An as-built inspection was pe rformed and sketches were made showing all the pipes and conduits attach'ed to each particular frame.
All attachments were identified by hanger number, seismic classification, conduit, etc.
The Bechtel home office provided pipe support load tables for the seismic Category I lines and computerized load tables of seismic loads on nonseismic Category I pipes.
- Review and design of modifications were conducted prin-cipally at the jobsite to expedite the process.
Most of the problems encountered were due to forces acting out of
~
plane of the frames, and were resolved by the addition of braces.
3.1.6.2 EQUIP!ENT NOZ2LE IDAD EVALUATION PROCEDURE Seismic Category I piping was reanalyzed where found necessary as a result of IE Bulletin 79-14 requirements.
Reanalysis of the piping systems resulted in a new set of loads being imposed on the equipment nozzles by the piping.
The new loads were evaluated in accordance with the following:
3.1.7.1 IDADS AND IDADING COMINATIONS The following loads were considered at the nozzles:
- Thermal loads at the worst temperature condition Dead weight loads
- Design (operating basis) earthquake seismic loads (OBE)
- Maximum Credible (design basis) earthquake seismic loads (SSE)
The following load combinations were considered:
- Thermal
- OBE + weight
- SSE + weight 3-8
~
3.1.7.2 BASIS OF CCr@ARISON The calculated piping loads on nozzles provided to vendors by Bechtel in 1970 and the original piping analysis were the bench marks for the comparison of new loads.
The following equations define the max imum forces and moments used for evaluating the acceptability of the imposed loads frm the reanalysis.
- Maximum allowable force Fr (Max) when all the moments are zero = Dxtxs a
- Maximum allowable moment Mr (Max) when all the forces 2
are zero = D xtxs b
Where D is a function of the pipe diameter; a, b 'are constant depending upon the pipe size; and S is the allowable stress in the piping connected to the nozzles.
(
Reference:
Bechtel Design Guide P - 2.6.1.11).
The loads calculated during the reanalysis required by IE Bulletin 79-14 were grouped together into the load combination described in 3.7.1 above.
The imposed resultant force and moment (Fr and Mr) for each load combination were then calculated.
Allowable Fr (max) and Mr (max) were calculated based on the documents referenced in Section 3.7.2 using the following allowable stresses:
Thermal Load: S = 22500 psi Weight + OBE Load Combination:
S = 18000 psi Weight + SSE Load Combination:
S = 27500 psi Calculated and allowable forces and moments were plotted in a diagram as shown in Figure 3-4.
If the calculated loads were found to be within the limits of allowable Curve 1,
the loads were j udged acceptable.
If Curve 1 was exceeded, Fr (max) and Mr (max) were calculated based on the calculated values in the original analysis.
Fr (max) and Mr (max) point was then plotted on Figure 3-4 and a parallel line was drawn to represent a reasonable basis for comparison, i.e., allowable Curve 2.
If the new loads were found to be within allowable Curve 2, the loads were considered acceptable.
If, however, the loads exceeded the limits of allowable Curve 2,
calculations were provided to Boston Edison for further action.
3-9 0"
3.1.8 EFFECT OF IE BULTETIN 79-14 RFRJAINSIS W PIPE BREAK OUTSIDE CCtTTAITNINT ANALYSIS A review of the seismic, thermal, and weight analyses performed during the IE Bulletin 79-14 effort was conducted to, determine the ef fect of these analyses on the locations of the postulated pipe breaks outside containment niven in Amendment 34 to the Pilgrim 1 FSAR, dated August 1973.
This review concluded that the maximum stress points in all sys-tems involved, as calculated by equations provided in the amend-ment, occur at the postulated break locations given in the amend-ment.
Therefore, no change to Amendment 34 is necessary as a result of the IE Bulletin 79-14 reanalyses.
3.1.9 FRICTIW IDADS Friction loads were not usually considered in the original pipe support design for Pilgrim 1.
However, at BECO's direction, friction loads were included in the review process for IE Bulletin 79-14.
Friction loads were developed and considdred as follows:
Calculated from weight and thermal loads applied normal to the support member.
The values used of the coefficient of friction were.
M.= 0.3 (steel to steel) u = 0.1 (use of lubricant) u = Negligible (use of lubrite plate).
For two or more nims supported by a common structure and to simplify the analysis, it was assumed that all were acting or moving simultaneously in the same direction, with all friction loads acting in the same direction.
The original pipe supports were designed basically for forces acting in one plane or in one direction and friction loads usually act out of that plane or in a different direction.
Therefore, this provides a conservative approach to reveiwina the adequacy of the pipe supports.
o jO 3 - 10 m-
~
3.1.10 REVIEW OF CRD SCPAM DISCliAICE VOIIJMES AND SMAIL PIPING l
A review of the seismic CatoJory I portion of the insert and withdrawal piping of the Pilgim Unit 1 CRD hydraulic systs was performed to detennine if IE Bulletin 79-14 requirments were applicable to these lines. W is 3/4-inch schedule 80 piping was designed to satisfy the rigid range criteria. Ehere the rigid range 4
criteria were not satisfied, the records indicate that an analysis was performed by Engineering [hta Systens to assure that these lines were adeauately supportal.
It is concludal that these lines were seismically quailified using the simplified analysis techniques and, as such, do not fall under the scope of IE Bulletin 79-]4.
4 j
A similar review was also ccnducted for the 6-inch-diameter scram discharge volumes.
his header is connected to the CRD modules approximately every 2 feet by a 3/4-inch diameter pipe and a group of vertical and lateral supports. Reactor Controls Inc.
seismically analyzed this 6-inch header as part of the CRD module. Since the header was qualifial under the cquipnent seisnic analysis, it was concluded that it did not fall under the scope of IE Bulletin 79-]4.
3.2 IE BUIJETIN 79-02
%e response to IE Bulletin 79-02 can be categorized in three major efforts:
(1) plant generic effort to determine design criteria and develop analytical techniques
(%is effort was reported to NRC per TES technical recorts 3501-1 and 3501-2); (2) plant specific effort to reanalyze piping support base plates considering the plate flexibility based on the information developal in (1); (3) field inspection and testing of achor bolts.
3.2.1 BASE PIATES AND ANCHOR BOLTS INSPECTION PROCEDURE i
A system-by-syston field inspection program was established to satisfy the IE Bulletin 79-02 Requironents. Boston Edison work instruction No. 201 provides details of the inspection procedure, acceptance criteria, and method of documentation.
l 3.2.2.
DISCREPANCY DISPOSITION Discrepancies (non-conformances) identified during plant operation were assessed inmaliately bred on engineering judgment. The intent of this assessment was to j
evaluate the impact of the discrepancy on the concrete expansion anchor bolts.
Alditional discrepancies were considered in base plate analyses to confirm the validity of the inital judgment.
3.2.3 BASE PIATE ANALYSIS PROGRAM AND SCOPE
%is proco3ure provided the criteria for reanalysis of Base Plates and Anchor Bolts utilized on Seisnic Category I piping systans in canpliance with the requirenents of NRC IE Bulletin 79-02. This procalure was sunmarized in our response to NRC BECo. letter No.79-137 dated July 9, 1979 and detailed in Boston Edison work instruction No. 204 Rev. 1.
3.2.3.1 BECHTEL SCOPE i
Boston Edison delegated to Bechtel, responsiblity for work in response to IE Bulletin 79-02 as follows:
Provide Boston Edison with revisal pipe support loads for base' i
plate and anchor bolt analyses.
3 - 11
)
1
_ _ _. _.. _,, _ _ _ _ _ _ _. _,. _ _ _, _ _. _ _ ~
=
a I
If no pipe support modification was rcquired, due to the IEB 79-14 review, a status report was updated informing Boston Edison to proceed with the 79-02 portion of the work.
If a modification was rcquired, due to IEB 79-14 review, a review of IE Bulletin 79-02 concerns was conducted by Bechtel and the results were factorcd into the support design modification.
Pipe supports attach (d to masonry walls with concrete expansion anchor bolts.
1 Large cmposite type supports which utilized concrete expansion anchor bolts.
Specific requests by Boston Edison.
3.2.3.2 TELEDYNE WORK SCOPE See Section 1.2 3.2.3.3 BOS' ION EDISCN WORK SCOPE Identify pipe supports using concrete expansion bolts in seismic category I piping systms subject to IE Bulletin 79-02 requirments per Boston Ediscn Work instruction No. 200.
Directed and reviewel IE Balletin 79-02 generic program perfomed by Teledyne Engineering Service for the utility owner's group.
Perfomed or directed engineering efforts of consultants for the plant specific base plate analysis per Boston Edison Work instruction No. 204 Rev.- 1 3.2.4 REVIEW AND ANALYSIS T BASE PIATES Boston Edison inspect (d the As-Built configuration of the base plates and concrete expansion anchor bolts associated with the Seismic Category I pipe supports and ompared it to the Design Documents. Identified discrepancies which exceeded the tolerances set forth by BIro's work instruction Ib. 201 were documented on As-Built discrepancy reports. %ese discrepancy reports plus the revised pipe support loads frm the IE Bulletin 79-14 work were incorporated in the base plate reanalysis per BECo's work instruction No. 204, Rev.
1.'-
The reanalysis of the base plates was performed to account for:
1.
We effect of base plate flexibility on the concrete expansion anchor bolts, and 2.
We minimm factor of safety between the bolt design load and the bolt ultimate capacity determincd frm static load tests. We reanalysis, if required, was perfomed using a generic, finite elment cmputer program which was developed by Teledyne Engineering Services. Wis ccr1puter analysis program accounted for Itms1 and 2 above and was used by BIro and Teledyne wheh the following conditions were not met:
(a) The unstiffencd distance between the mmber welded to the' plate and the edge of the plate is equal to or less than twice the thickness i
of the plate.
(b)
Bolts are not in tension for all loading cases.
3-12
-- - =
(c) Bolts are in pure shear for all loading cases.
(d) When the follwing equation is satisfied for rectangular plates with two or four bolts of symetrical arrangment:
Kft+
s 51 t
s
= Bolt tension load obtaincd frce rigid base plate analysis Where:
ft f = Bolt shear load cbtained frcm rigid base plate analysis s
F = Ultimate tension capacity divided by factor of safety, t
4 or 5 as required per the Bulletin
= Ultimate shear capacity divided by factor of safety, F
4 or 5 as required per the Bulletin s
K = 2 This conservatively assumes a 100% increase in tension loads (f ) due to plate flexibility. Our studies indicate that maximum increase in tension loads due to plate flexibility t
is approximately 60%
'Ihe more complex base plate anchor bolt configurations that were encountered which could not be evaluated using the generic ccmputer program were delegated to a local engineering firm for analysis.
Those base plate and anchor bolt analyses which became part of Bechtel's scope because of an IEB 79-14 relatcd support modification were performed using Bechtel's BOLTS program, version D.
3.2.4.1 CODES, STANDARDS, AND CYIHER REFERENCES IE Bulletin 79-02 related structural modifications are in accordance with the requirments of the FSAR criteria. The allowable stresses for the various types of concrete expansion anchors were based on requirements of the IEB 79-02, and the Manufacturer's suggested Allwables verified by Teledyne wners group's For those generic program subnitted to NRC per TES technical report 3501-2.
I cencrete expansion bolts utilized on masonry walls, an interim allowables table was taken frcm FFTF data, as reference in revision 2 of IE Bulletin 79-02.
3.2.4.2 MODIFICATICE DESIGN SEQUDCE Nhen the review process identified concrete expansion anchor bolt loads that exceeded the IE Bulletin 79-02 allowables, a modification was designed to restore those As a result of the IE Bulletin 79-14 piping reanalysis many of the allcuaSles.
Boston Edison transmitted t previously Irodified base plates had revised loadings.
Bechtel copics of the ccmpleted base plate modifications to Bechtel for their review.
then incorporated these changes into their IEB 79-14 related pipe ' support review calculaticris.
t o
I I
i I
i 3-13 l
- PERFORM WEIGHT ANALYSIS
- COMPARE SPRING LOADS 1
FROM OUTPUT (GRAVITYI TO:
1.
LOADS ON AS BUILT SUPPORT DETAIL 2.
AVAILABLE LOADS FROM FIELO
?
YES COMPARISON AGREEMENT 7 NO PERFORM WElGHT ANALYSIS SPECIFYING FORCES AT ALL SPRING LOCATIONS.
FORCES ARE TO BE OBTAINED FROM:
- FIELD DATA (READING)
'.1
- DET AILED SUPPORT "1
DRAWING IF FIELD DATA
~
IS NOT AVAILABLE t
G tI c
15 FIELD PROVIDED READING NO OUTSIDE WORKING RANGE OF
,t
^
SPRING 7 1
lYES
'7 4
REDO WElGHT ANALYSIS SPECIFYlNG RIGID SUPPORTS FOR SPRINGS OUTSIDE WORKING RANGE I
l 4
15 COMPUTED WEIGHT LOADING NEW COMPUTED LOAD IS WITHIN WORKING UNACCEPTABLE. NEW SPRING RANGE OF THE SPRING?
NO IS NEEDED YES 3
7 3
FIELD TO ADJUST SPRINGS SPRING LOADS ARE TO THE COMPUTED LOADS ACCEPTABLE FIGURE 31 WEIGHT ANALYSIS - CONSIDERATION OF SPRINGS
s.
e
=
s h
h 5$
..i 3
G
_1 a
j I
l1
.S f1
.i i..:e Ii.
I a.
1
.i.s;
.i.,
5 i
c 9'
a j!vig
=)
o ga e I
v
.i
-}
.i.I I '.I i.
2.
.s=
1 g l.g g19
.ma
==
8 1
et
! : i 15 liii5 l
59 3x a
8 rii!!
I II i
a m
n :.
i 22 m
Eif.
I b
i c!E !
g' O
a 89 i H
d.
N E.i.a!
<l I
l
[
E 1
l
's r : i 21 8
., k, !. i. l. 1 as s
I
!. a E.!
a s
ia II I
g i!iI!-!!ii Ii
' Ig 8 '
=
s
{.I i.
i 1 r 3
a
-E 8 3 i
8 5, :
9 a c.
I c
1;s u
E 5
I i
O gl 3
i E oi 3 1 I
I
.1
! I
!]
=E la,ls]i
-a g 3: 3 a
3:
r em
.!!s iilill!
e i l l sl 1 3
- E i
- c.
I-
.! ! s s s s i asis!!
il 3I k
9 e
e e
4 RIGID HANGER E
RESTRAINT Q.
GUIDE (2 WAY)
O O
SPRING HANGER 4
i SNUBBER y
ANCHOR d
FIGURE 3-3 PIPE SUPPORT TYPE e
a 0
e e**l
\\
\\
M (max)
\\
r
\\
\\
\\
\\
'\\
\\
\\
\\
ALLOWABLE CURVE 1
- a 1
\\
E
\\
\\
w M
\\
CURVE 2 g [(ALLOWABLE BASED ON ORIGINAL LOADS) g o
4
\\
M, (ORIGINAL LOAD)
..\\.
i\\
\\
\\
........O..S.E.D...F.O R C E.....
IMP (RE ANALYSIS)
\\
i
\\
i i
\\
- s i.$
\\
w : v, 2 : iF>
- s
\\
0:>
.s
\\
E.:
.z
\\
c:<
\\
z w:<
E!=
18
\\
s:-
\\
- i l'
\\
\\s F,(, nam)
FORCE (F,)
(
FIGURE 3-4 EQUIPMENT NOZZLE REVIEW FORCE / MOMENT DIAGRAM
SECTION 4 REVIEN AND ANALYSIS RESULTS 4.1 PIPING, SUPPORT AND BASE PLATE StM&RY Following are the overall statistics for items involved in the review and analysis performed in response to IE Bulletin 79-14 and IE Bulletin 79-02.
Total number of seismic Category I 87 isometrics Total number of seismic Category I 1059 Supports Total number of non-conformances 1047 identified For both 79-02 and 79-14 a.
Pipe stress in put parameters 275 (79-14) b.
I-iping 'As-Built' vs. design 560 documents (79-14) c.
Base Plate 'As-Built' vs. design 212 documents (79-02)
Total number of support nodifications 319 (79-14) a.
Supports with stresses that exceeded 153 the operability criteria.
l b.
Supports with stresses that exceeded 166 allowables but fell below the operability criteria Total number of base plate modifications 49 Total number of support modificaticns 4
awaiting implementation Note that an inoperable support or base plate did not necessarily cause a system to be inoperable; see sections 3.1.5.1.1 and 3.2.4.2 for details.
e l
4-1 l
m
+-
M
SIITICN 5 DOCLEENTATION The results of the review and analyses are documented as indicated in the following.
5.1 INSPICTION EFFDRP IEB 79-14 related non-conformnecs are documnted on deviation disposition forms, see Figure 5-1.
IEB 79-02 related non-confa nnces are docurated on Discrepancy Report Forms and in the revised base plate calculaticns.
5.2 INPtJr PARA >ETERS REVIEW A list of input parameter deviations was prepared for each seismic Category I iscrnetric. The piping iscmtrics were mrked up to show the location and type of each deviation.
5.3 PIPE SUPPORT FDDIFICATIONS A new design drawing was prepared by Bechtel for each nodified pipe support.
As-Built dimensions, including design changes made during the installation 7
phase, were incorporated in these draaings. 'Ihe adequacy of the remining seismic Category I supports was documnted in review calculations.
5.4 BASE PIATE bODIFICATIONS A base plate nodification sketch was prepared for implementation of the modification. After the modification was ccnpleted the sketch was revised to reflect the 'As-Built' condition. The 'As-Built sketch was then incor-porated into the Revised Support Drawing.
5.5 PIPING ISObEIRICS New isomtric drawings for all Seismic Category I piping systems were prepared by Bechtel. 'Ihese new iscutrics incorporated all deviaticns identified during the IEB 79-14 inspection of those systems.
5.6.1 PIPE STRESS CAILWATIONS Revised pipe stress analyses were prepared by Bechtel which incorporated the 'As-Built' configurations of the systems. 'Ihese analysis have been transmitted to BEco and have replaced the existing analyses.
5-1
5.6.2 PIPE SUPPORT CAICUTATIONS All pipe support calculations were reviewed by Bechtel. Anym changes or revisions required due to support load changes were doctrmnted in the calculations and on the support drawings. Bachtel's support review.also docunented any changes due to the 79-02 review.
5.7 DOCU' E T COtCROL IEB 79-14 required a description of measures which are in effect which provide assurance that future rrodifications will be reflected in design doctrmnts and seismic analysis. BECo presently has specific procedures and guidelines to assure that these concerns are inple. ented. 'Ihose proced-ures are listed below for your inforration.
NED Procedure 3.02 " Preparation, Verification Approval and Revision to Desian Doctrents" NED Procedure 3.05 " Design Calculations" NED Procedure 6.02 " Drawing Control System" PNPS Procedure 1.3.13 " Plant Design Changes" l
l l
I 5-2
BOSTON EDISON COMPANY PILGR!x STATICA Uh17 #1 I.E'.Bulletin 79-14 Civil / Structural As-Built Deviation Disposition TRAN5MITTA!. TO:
F. N. FAMAARI ENOLOSED DEVIATION NO: 7g-14
.j D15P051T10h:
1.
Affe:ts: D 1.E.Bulletin 79-02 Work O I.E.Bulletin 79-14 Work DPipeSupport-O Stress 2.
Responsible Organization:
(
O Bechtel C BEco (79-0?)
C BEco (79-14)
~
O General Ele:tric O TEs D0ther 3.
_Docu-ented in Calculations:
Oyes O No ONotRequired 4.
Modification Reautred:
O Yes CNo
'~
C Restore to Drawing Configuration MF Naber O Modify Support PDOR Neber t
f -
J FIGURE 5-1 (Sheet 1 of 2) l
FO' Low'-US DO:W.ENTAi!ON ACTIONS REQUIRED:
D !ssue t<N Against Drawing No.
O Confi9uration D Lead Table s
OBillofMaterials COther-O Yoid Drawing No.
,j O Replace with Drawing No.
- O Stamp with 79-14 Verification Stamp (Re'f.T.P.79-21)
O Other Dispositioned by Date CIS Group Leader Date
{
f l
l{'
FIGURE 5-1 l I.
(Sheet 2 of 2) l
~
l