ML20127H209
| ML20127H209 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 11/12/1991 |
| From: | Peters A TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | |
| Shared Package | |
| ML20127H203 | List: |
| References | |
| RTR-NUREG-0797, RTR-NUREG-797 2-NP-GENX-551, NUDOCS 9301220254 | |
| Download: ML20127H209 (17) | |
Text
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FlCURE 7,i aEP-ios ENCLOSURE TO TXX-93024 REVtsiOH a PAGE 1 0F 17 CALCULATION TITLE PAGE PACE 1 OF t FAGE1 TEXAS UTILmES ELECTRIC CO. / CPSES UNIT 2 H
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CALCUt.ATION CLASSIFICATIONS:
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4 ENGLOSURE TO TXX-93024 2EP-5.cs PAGE 2 0F 17 Revision 2 Page 1 of 1 4
FIGURE 7.4 COMPUTER OUTPUT / CROSS REFERENCE ORGANIZATION:
BECHTEL,PSAS 0935 JOB No.
CALC NO.;
2-N8~d8NX'I[/
REV.
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2EP-5.0P,-3, Revision 2 Rtc. Type Code: 5A.100
1 i-ENCLOSURE TO TXX-93024 J
'PAGE 3 0F 17 I
CALCULATION SHEET
)
PROJECT COMANCHE STEAM ELECTRIC STATION-UNIT 2 JOB NO. 20935 CALC. NO 2 NP-GENX-551 REVJ PAGE 3
J t
SECTION I j
TABLE OF C MTEXTS SECTION N0.
PAGE NO.
TITLE PAGE 1
COMPUTER CROSS REFERENCE 2
i I
TA81.E OF CONTENTS 3
REVISION STATUS 4
11 OBJECTIVE 5
111 BACKGROUND 5
j IV ASSESSMEhT 6
V CONCLUSIONS 8
VI REFERENCES AND DOCUMENT REVIEWED i
8 VII ATTACHMENT 1 1-6 ATTACHMENT 2 1-2 r
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ENbLOSURETOTXX-93024 PAGE 4 0F 17 CALCULATION SHEET PROJECT COMANCHE STEAM El,ECTRIC STATION. UNIT 2 (OB NO. 20935 CALC. NO 2 NP4ENX-S$1 REV.O PAGE 4
a REVISION STATUS TABLE REY NO.
PAGE NO.
DESCRIPTION / REASON, O
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CALCULATION SHEET PROJECT COMANCHE STEAM ELECTRIC STATION-UNIT 2 JOB NO. 1Q935 CALC. NO_ 2-NP4ENX-551 REW 0 PAGE - 5 SECTION 11 OBJECTIVE The objective of this GENX calculation is to review the requirements of NUREG-0797 Supplement 14 determine the action neces(sary to disposition these requirements.S SECTION III BACKGROUND l
The full text of SSER 14 Appendix A sections 12.1 and 12.2 is contained in to this GENX calculation.
As stated in the SSER, the primary concerns were: support designs using dual struts / snubbers were not adequately modeled in the piping analyses and could restrain the rotation of the pipe and cause local overstress at welded attachments, and support designs using dual struts or snubbers could restrain the piping system and cause an increase in the design loads for the struts and snubbers.
SSER-14 states that the SWEC methodology, in this case CPPP-7 Revision 3, in general, properly accounted for the rotational restraint effects and the calculation of design loads for dual supports.
An example of the NRC acceptance of the CPPP-7 methodology is shown in Attachment 2.
CPSES Unit 2 utilized design criteria 2EP-5.12 and 2EP-5.13 which contained identical modeling methodology as CPPP-7.
However, section 12.1 of the SSER contains a portion which states:
However, the staff finds that piping system stresses and pipe support loads may be underpredicted in long straight runs of pipe with a series of adjacent integrally welded dual trunnion type supports (or single stanchion trapeze i
type supports) modeled with moment restraining capability.
The SWEC modeling procedure will be conservative for supports at the ends of the series but will be unconservative at supports interior to the series.
The i
staff finds that the SWEC resolution methodology is acceptable for consideration of rotational restraint effects with the above noted limitation.
The staff requires that any such piping and pipe support configuration identified in i
the CPSES design validation be subject to a case-by-case evaluation and the rerolution be provided to the staff for its review."
e:\\atp\\sser--14 s-November 7, 1991
4 ENCt.05URE'TO Txx-93024
'PAGE 6 0F 17 J
CALCULATION SHEET PROJECT COMANCHE STEAM ELECTRIC STATION VNIT 2_ JOB NO. 20935.
CALC NO 2-NP-GENX451 REVm0 PAGE __ 6 i
i Section 12.2 also contains a similar statement.
i The requirements as stated in sections 12.1 and 12.2 of SSER-14 Appendix A are unclear in two respects.
First, the technical basis for the potential underprediction of loads and stresses on long straight runs of pipe is not stated.
Second. the nature nf the evaluation the - SSER requires to be performed is not stated.
A review of the various backup documents did not reveal any basis for the SSER-14 statement, nor did i
informal discussions with engineers involved with this issue when Unit I was being completed.
Therefore, this GENX calculation assesses the various analytical modeling parameters as required by the design criteria requirements of 2EP-5.12 and 2EP-5.13 associated with piping and pipe supports which could conceivably affect piping stresses and support loads on long runs of pipe.
SECTION IV ASSES $NENT
(
1.0 Consideration of Large Bore Piping i
The first parameter assessed was the general modeling of single or dual i
. eccentric supports. The basic original concern in this area was that Gibbs and Hill modeled dual eccentric supports as single non-eccentric supports which did not represent the actual rotational restraint in the computer model.
This modeling technique.is r.o longer used. CPPP-7 Rev 3 and 4 and 2 EP-5.12/5.13 provide clear direction as to the modeling of this type of I
support such that they are modeled as dual eccentric supports to properly l
account for any rotational restraining effects.
The second parameter assessed was the modeling of pipe support stiffness.
CPPP-7 and 2EP-5.12/5.13 require the modeling of pipe support stiffness i
for all pipe supports.
This provides accurate results for both the supports at the ends of long runs of pipe as well as any interior
}
supports.
The third parameter assessed was the CPSES practice of not modeling pipe support gaps or end clearance effects for struts and snubbers.
End
. clearance effects were evaluated for snubbers in SSER-14 Appendix A l
section 12.3.
The matching of snubber pairs for differential lost motion l
at CPSES was concluded to reasonably predict snubber design loads.. It can.
I e:\\atp\\s**e-14 6-l November 7, 1991 E
ENCLOSURE TO TXX-93024 PAGF 7 0F 17
[
CALCULATION SHEET PROJECT COMANCHE STEAM ELECTRIC STATION UNIT 2
_ JOB NO. 20935 CALC, NO__2 NP-CENX451 REv<0 PAGE __ 7 clearances are similar to snubbers.be extrapolated that strut load also found to b0 acceptable. Pipe support gaps were evaluated in In addition there is no mention of support gaps contributing to the original concer,ns stated in sections 12.1 and 12.2 in either SSER 14 or any backup docus.entation.
It is an acceptable general industry practice not to model normal pipe support gaps or snubber /3trut end clearances in stress analysis calculations.
Given that support modeling, stiffness considerations, and allowable tolerances are rigorously implemented (por the requirements of 2EP-5 12 5.13 and 5.14 the ME101 analysis results will accurately and realistically r)e,present the response of piping systems distribution of loads / stresses interior to any series of such supports.
including the 2.0 Consideration of Small Bora Piping The discussion in 1.0 above applies similarly to small bore piping wit the exception of the ap final reconciliation. plicability of support stiffness tolerances during Calculation 2-NP-GENX-539 documented a basis an justification of final reconciliation of small bore piping withnut application of specific tolerances on support stiffness.
involving a series of dual struts / snubbers on a s On that basis it occur and result in redistribution of loads within the series.
, may however demonstrated that GENX-539 in general terms, significant changes in small bore support stiffness res, ult in insignificant effects on system respo and adequacy.
In addition, occurrences of a series of 3 or more dual struts / snubbers on straight runs of small bore piping are not expected due to the typical nature of pipe routing and the mix of support types used Therefore, small bore piping systems are also acceptable without furthe evaluation, e:\\ntpisser 14 7-kovewber 7,1991
i 4
i-ENCLOSURE TO TXX-93024 l
PAGE 8 0F 17 CALCULATION SHEET
(
j PROJECT. COMANCHE STEAM ELECTRIC STATION. UNIT 2_. JOB NO.. 20935 CALC. NO 2-NP4ENX 551 REV O PAGE 8
s i
i SECTION V CONCLUSIONS 1.0 Large Bore Piping Based on the above assessment, the modeling requirements for dual supports clearance,s, and allowable tolerances for these attributus provide a i
analytical results and are consistent with acceptable industry practice.
Due to the rigorous nature of implementetion of these attributes, no 4
additional case-by-case evaluations are necessary.
ME101 res,ults wil t realistically represent the system responso including distribution of forces / stresses on the interior sections of the support serios.
1 2.0 Samall Bore Piping No specific evaluations are necessary for small bore analyses parformed during the Unit 2 validation phase of the work for similar reasons as the large bore systems and GENX-559 has shoc potential changes in stiffness to be insignificant.
SECTION VI REFERENCES AND DOCUMENTS REVIEWED 1.
i NUREG 0797 Supplement 14, Appendix A. " Safety Evaluation Report reisted to the Operation of Comancho Peak Steam Electric Station, l
Units 1 and 2", USNRC, March 1989 2.
DAP-E-P-012, Comanche Peak Design Adequacy Programs, engineering evaluation, dated (approved) July 9, 1987 3.
Attachment A to DAP-E-P-012, Summary No. ESIS-P-012, Rev. 2, dated July 6. 1987 4.
"Large Bore Pipe Stress and Pipe Support Generic Issues Report",
Rev 1,. Stone a Webster Engineering, April 6, 1987 S.
2EP-S.12, ' Design Criteria for Pipe Stress Analysis and Pipe Supports", Ret 0.,-sections 3. 7. 5, 3. 7. 7. 2, Tables 3. 7. 7-1, ~ 2, - 3, i
-4, & S.
Table 3.7.8-1, attachment 4 8 i
e es\\atc\\aser 14 November 7, 1991 i
l' ENCLOSURE YO TXX-93024 PAGE 9 0F 17 CALCULATION SHEET
[
PROJECT COMANCHE STEAM ELECTRIC STATION-UNIT 2 JOB NO.
34 CALC. NO-2-NP-GENX451
~
REV.O PAGE. 9 l
6.
2EP-5.13, " Comanche Peak Steam Electric Station Design Guidelines" Rev. O, Attachments 3 4 and 3-11 f
7.
CPPP-7, " Design Criteria for Pipe Stress and pipe Supports", Rev.
4 sections 3, 10, 8, 4.0, tables 3.10.8 4 & -5, attachments 4-8 and 4-18 C.
Conenitment Data Forms for Register Numbers SSER-14-008 and SSER,
009 9.
15454-NZ(C)-GENX-042, Rev 0, " Justification of Design Load for Struts / Snubber and Lugs Used in conjunction with Riser Clamp" dated March-13, 1976 10.
2EP-5.14, " Procedure for Pipe Stress / Pipe Suppcrt (Scope A) Final iteconelliation"
\\
11.
2-NP-GEKX-539 Rev. 0,
" Exclusion or Reanalysis of Small Bore Piping for Stiffness Variations," dated August 28, 1991 t
l SECTION VII ATTACHMENTS 1.
SSER-1-4 Appeadix A Sections 12.1, 12.2, 12.3 and 13.4 r
-/4 2.
l SSER/AppendixASection4.1.2.2page4-10and4-11 i
f
'9 es\\atp\\sser 14-9*
Noveab,r 7, 1991 i
1 l
.l ENCLOSURE TO TXX-93024
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.--:.......,,..,c The staf f esaluation is provided in Section 2.2 of this appendix.
j 11.3 Concluston i
j gasas on the above.evaluatiens, the staff concludes that the concerns
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associated with U bolt cinching have been adequately resolved.
The generic technical itsue concernir.g U troit cinching is, therefore, closed for CPSES.
12 AIIAL/ROTAT!0hAL RESTRAINTS i
j A number of concerns were raised regarding pipe support designs which coulc potentially restraic the piping in an axial or torsional direcion (axial / rotational restraints). These concerns mlated to the fellowing three types of exisl and/or trapeze-type supports which utilize welded lugs or i
trunnions to transfer loacs to frames or c6aponent standard supports (i.e.,
snubbers or struts):
l (1) single or ocuble intefrally telced trunnions with dual cuapcnent standaN suppc r':s 1
- C ner-trunnion typs supports Trapete supports with U-bolts kiser c1m and integrally weldad lugs with dual component standard supgcrts Riser clamo anc' integrally =41ded lugs with single eccentric l
compenent standard su.oport i
(Ji frare with integrally welced lugs tyne supports.
l i
TENEH icentifisc 2B separate issues related to these restraints during their l
WJ revt=w of external source documents. These issues were categorized by TENERA in Engineering Evaluation DAP-1-F-012 "Anial/ Rotational Mestraints." into 6 broad areas et concern.
M y '1) l C*p d (2) component support design load for_ oval supports aQ stress ano loa.e 411c.webles
{As (3) lug load dstributtor.
(4) cinched U-bolts on trapeze supports-l E
j $( (6) 5)- loao point
- application-on frames from lugs
(
eccentricity of single / double trunnion supports d%
The above six concerns are ciscussac in the seven issues below which have been j -
reforsatted for c1&rity.
1 s
@9 i
12.1 Rotational' Re*,traint Effects Q Pipine Systems
'%c This issue'is coscribed in DA? External-source Issue Susmary E3!5-P-012 (Section 1.4).
The SWEC resolution methodology is.provided in the Piping 1
project status reports (Sectior. 2.1 of Subsppendia A12). The DAp evaluation >t provided in Engineering Evaluation DAP E-P-012:(Section 5.7.2) ar.d is sumarized in the piping results report (Sections-3.2.3.12).
I J
Comanche Peak SSER 14
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' Appendi8 a
rtict.050RE TO TXX-93024 hAGE110F17 ATTACHMET No I
o P; a 2 e b CA1.C NabHP-bfwx-C5"/
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-,,_ Am. mC e The pri#ery concern was that support designs using dual struts / snubbers w not adequately modeled in the piping enelyses and could restrain.the rotation of the pipe and cause local overstress at the welded attachment..The SWEC r;ssolution methodology requires that the rotational re ano (2) the eccentricities of riser clamp and single trunnien both with sing component standard supperta be modeled in _ the pipin addition, nonintegral (1.4.. riser class with lugs)g stress-analyses.
In dual component standard supports are regetred to be medeled as translationalas with a single component standati support. - procedures for appropriate alternative are based en critaria for the stiffnesses of the two legs of the nual component standard type support.
Baseo on the modeling procedures for inteprs11y welded trumion type supports with egal component supports, and riser c amp and single trunnion with a single eccentric component standard support, the staff finds that rotational restraint uffects have been adequately included in the piping and pipe support design y
metnocology.
The proceeures provide assurance that for oiping systans-and loads in the component standard suppsats under the ap loading conditions will be reasonably pracacted.
However, the staff finds that piping system stresses and pipe support leeds may be underpredicted in long straight rvr.s of pipe with a certes of adjacent -integrally welded dual with moment restraining capability. trunnion type supports (or single sta The SWit modeling procedure will be conservative for supports at the anos of the-series tut will be unconservatwe -
at supports ir.terior to the series.
metnocolo;y is acceptacle for consideration of rotational restraint effects 8
pipe support configuration identified in the Cp5f5 design val subject to a case-ty. case evaluation ano the resolution be provioed to the staf f for its review.
8asec on the modelino and sodification precedures and stiffness criteria for nonintegral f riser c' amp with lugs)' axial type supports' with dual component supports, the staff finds that rotational restraint effects have also been aeecuately included in the piping and pipe support design methodology.
stiffness criteria for the two legs of these supports pecvide an acceptable The basis for identifying supports with rotational restraining capability.'
criteria were 41se reviewed by TIMERA and found to be acceptable.. supports cf
.These this type with negligible rotational restinining capability are modeled as translational restraints at the-pipe centerline.
staff finds a limitation in the 5WEC methodology with underpredictions ofAs previ piping stresses and pipe support loads _in long straight runs of piping witn exial supports.. The staff finds-that the SWIC resolution methodology is acceptable for ths consideration of rotational 6fects in these types of supports subject to confirmation that the preceding described piping and pipe support configurction be ioentified to the staff for final riesolution.
12.2 Rotational Restraint Effects on Component Standard Desien-l.oads This-issue is described in DAP External Source Issue Swruary E5!$.P-012 (Section 1.6).
The SW C resolution methodology is_provided in the ptptng Comanche peak $!!R 14-Appendix-A s
l 1
1 CNCLOSURE TO TXX-93024 l
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PAGE 12 0F 17
}
J ATTACHM3NT No_-
1 FA358o" & _]!
OLC Ny-NP-GEHX-C$*/ r~l O l
g._.
l project status reports ($cetions 2.1 ano 2.2 of Subsppendix A12) evduation is provided in Engineering Evaluation The DAP l
i The primary concern was that support designs using dual struts er sn could restrain the piping system and cause an increase in the desig ti.e struts and snubbers.
desigri loads for component standard supports be base j
fror the piping anc pipe support system stros analyses as follows l
the support type.
Fce supports with riser elane or single trunnien aW single eccentric i
standard support, the component standard supports are to be modeled as eccentric translational restraints-in the piping and pipe support system st analysis and their design loads are to be assumed to be equal to the loa l
obtafned in the stress analysis.
1 For dual trunnion type supports with dual component standard suppo i
with rotatieral restraints in the piptog and pipe f.upport system stress a
analysis, the design loads in struts and snubbers are to be assumed to 100 percent and 120 percent, respectively, of the loads obtained in the stress analysis.
effects of differential snumber lockup.The 20 percent increase for snub i
l t
For supoorts with riser clamo and dual compon l
the casign load of each of the f.omponent standard supports is to be assu
(
ot equei to 75 percent of the load obtained in the stress analysis.
j o
percert design factor was supported by calculations The 75 Luss unses in conjunction with Riser Clamps" (GEN 1-042).
(
conservatively assumac that the load is uneeually distributed betwen theThes only, four li.9s ars typi: ally used.ceroonent stir. card supports due t i
the counding factor over the range of geometrical configurations i
This calci.lation was reviewee by the staff and found to be acceptable acettion. TENCkA reviewed the SWIC calculation and deemtent In Engineering Evaluation 0AP-t-P-057 " Review of Calc GEhX-042."
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concluoed that the SWEC method is adequate since it is based on applicatio The DAP i
sirple statics..
i cesign loads for component standard supports in supports are acceptable.
4 For long runs of pipe with A series of dual trunnion i
type supports or antal type supports, the staff finds that leads in the pipi and pipe supports may be underpredicted and the resoluticq of any such identified configurations should be evaluated on a case 4y-case basis and i
provided to the staff for its review.
+
The staff conducted an audit to verify the adequacy of the design criteria application in the design valiotion (Appendix 0 to this supplement - Event 37).
i FW 2-101-404-CSIR. Revision 1; FW-2-105-410-5828The staff L'
Revision 4; and AF 2-096-445 543R. Revision 1.
dual component standard supports.These designs were of riser eless and lugs m The staff found during their review of 5d.
- 1 Comanche Peak SSER 14-
$ Appefidi x a m..A
ENCLOSURE TO TXX-93024 PAGE 13 0F 17 ATTACHMCNT f 6
/
P/,GE A o" l c/,Lc No 2 NP-GN M/ r;w i
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1 i
based on the-asseption that the eats of symmetry o i
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clase was oriented at 45' to aejacent Ivos.
i TD epa had found that the load atstr169 tion in the support would vary s' gnificantly depending on the lug /clasic orientation.
inspected was controlled and consistent with the orie Calculation GEU -Oat.
i orientation in riser cleap andAccordinply, the staff found that the lug / clamp ugs with dual camponent standare supports appears to be controlles ta ensure that the load distrib GEU-042, and is thus acceptable.
12.3 Differential %stber Lock-ve and tad Clearances Effects on Saub pel1en Loais 'n Uval 34Weser 202M5 This issue is described in DAP External Source Issue Samery ES!5-P-012 l
(Sectico 1.1).
project status reports (Sections 2.2 and 2.3 of Sebappendi i
and is summarized in the piping resu' ts rep?rt (Section 3.2.3.12). evaluation is provided in [
The DAP i
i Concerns were raised that the desion loses for dual snubber supports did no adecuately consider tne effects of ~ differential lock-up stiffness variations, support clearances, and dual-suppo,rt clearance-support steel ci f ferences.
ocal trunreton supports, the design load for each snu i
structure be increased by 20 percent above the loads obtainac fmn the piping i
and pipe support system stress analysis (2) for nenintegral dual snubber supports, each snubber is designed for 75 percent of the total support loac cetained from the piping and pipe support system stress analysis, ano (3) snueber pairs in dual snubber supports will be matches in accordance with ane Department of Energy Nuclear Stancard Mt-t7 gf
- Mechanical and Hydraulic Snuboers for huclear Application," (Reference A33).
used on the 20 percent increase for_ integral. dual trunnion supports, the 50 percent (75 percent versus 50 percent) increase of half of the total ioaa for.
non-integral eual snuther supports, and-the caemitment to astch paired snubbers in accorsance with Standard NC-t methocology procedures are accep? ST, the staff finds that the 5Wic resolation snubber lock-up in dual snubber supports. table to resolve the effects of differen reviewed by 7th(RA and found to be acceptable.These procedures have also-been_
'i The 20 percent increase in design lead is_ consistent with manufacturer's recommendations and is usual applied when snubbers are matched in accordance with Standard N(-17-9T.
t in the case of the effects of differertial and fitting clearances on (1) loac sharing and-(2) the validity of the results of linear methods of analyses as '
described in NOAEG/CA 2175'
- Snubber Sensitivity Study * (Reference AM), the SWEC resolution esthodoloy does not impose aey limitation en differential.end_
fitting clearances in 4uai snubaer supports.- TDERA has condweted a esta11ec j
review of the NUREG/CR-2175 test cata in its' Engineering Evaluation DAP-E P-OH i
"Dtfferential Snubber Lock-up of Qual Snubber. Assaeblies? and found that the MURIG provided sufficient data to conclude that strut /ssabber end clearances I
can have an effect on predicted loans.
However, it was concluded that the h0RfG did not provtee sufficient basis with which to establish the magnitude o' such effects or specific criteria to account for such effects in the design t
Comenche' Peat 55tA 14
- 36 ApPendia A L
I
i Et4 CLOSURE TO TXX-93024 PAGE 14 0F 17 ATTACHMENT No
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W.GE f o" b j
CALC No2 NP-6EN/-ff/ Ray i
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The Standard Review Plan (NUREG-0000 process.
i Section 3.9.3 *the snubber end fitting clearanc)e(and lost motten must i
minimiste.and should be considered when calculating snuper reaction loads and stress which are based on a lineer analysis of the system or component...
Ecual load sNrir eismatch in end fj+ ting clearance exists.*of multiple snubber supports shoul 1
The hAC staff identified end i
50-446/88-09 (Rderence A35).f1tting clearance ss an unresolved itse in i
a followup inspection report.
The resolution to tAis item will be addressed in in the piping project status reports (Section 2.3 of Sebappendix A12) ti.e SWEC methodology is to match snuper pairs used in dual component type applications in accorsance with Standard hE t? St. The staff mviewed $WC Calcul 15454-NZ(c)-4fNX-242. " Parallel $nuMers" for the matching of such snuper pai rs. Standard MC f 7-97 requires that (1) differential I
est action between the snubber pair shall not exceed 0.02 in, and (2) differential activation i
level between the snuper pair shall not exceed 0.00$g or 50 percent of the smallest of the activation levels o< the snuabeyr 1r ; Tha staff review found that of tha 235 supports evaluated:
(1) tMT.W14CSI i
criterien was satisfied in 100 percer.t of the supports. sed (if 't tion
- 8 sifferettist'setitattee level was satisfies to 83 percent erthe, rt s The SWC calculation concludee that supports not in compliance with tA l
ctf#erential activation level criterton were acceptable on the basis that i
matchirg of activation levels for proper load sharing in snubber pairs was not i
industry practice.
(and missetch of end fitttiT'therence) had a' greater effect en th i
snaring of tMit indbers thasLdees, the etsmeseh-e#cestgvestm level as statec i
(
in Stantere Review' PfaA WURtt 0800 particularly evicent for mechanical (hoference A36) in Section 3.g.3.
This is
}
snubbers subjected to rapic cyclic loadings i
l such es earthouake lo441ngs.
In NUREG/CR-2175 (Reference A34), the test results indicate for aero end fitting (50/50) was obserclearance l
activatior. lev escal loan shar' ved to en accuracy of 3 percent.
siff ly thd c
O,asts to W
12.4 Cesign Allowables for Qual Component Standard Ex:rts The issue is described in OAp External Source issue temmary ES!!-P 012 (Section 10 The SE C resolution metnodology is prevised in the piping project status reports ($ection 2.1 of Sub40peadta A12).
The OAp evaluation is provided in Engineering Evaluation DAP-t-P 012 (Section 5.3.2) and summarized in-the pip results report (Section 2.2.3.12).
A concern was raised regarding the treatment by Sins and. Hill of support 1caes resulting frc1 rotational restraint of the piping seismic displacements as secondary loads. As-seconeary. loads, the resulting support alleuables were increased by a facter of three. The SWC resolutioe methodology reeutres that Icads in dual component standard supports modeles as rotational restraints be classifieo as primary loads.
The staff fines that this classificatica is acceptable to resolve the concern. The ASM Code three times increase in allowable stresses for the constreint of free and displacement is not invokec.
U.5 Cinched U bolts in Trapere Supports Comanche Peak SSER 14
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Appendix A-l-
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i FNCLOSURE TO TXX.93024 j
PAGE 15 0F 17 j
ATTACHMENT No_
/
PAGES ** (o 1
q CALC No 2'.NP* CdH*~LX! REV__
Q l
=
evcutrtreMs =4s cer'fonnec in conjuhetion with its rev l
inis late- ;cce.rovis*en acceptacle.
'3.3 j0l! 3dDs i
The issue bacqrcund ts ciscussed in OAP External Source Issue summary i
i ESIS-P 013 ( Attaenrent A to 0AP E P 013).
}
proviceo in the Diping project status reports (Subsppendit A4 Sec i
ine OAP evaluation is provided in Engineering Evaluation DA# E P-006 U.ttachment C).
i U bolts were initially designec at CPSE$ as one wa i
pipe in tav cirection parallel to the U-bolt legs)y restraints (restraining the The gap between the U bo h 1ees and the pipe varied up to 1/16 inch. The concent was that when pipe movement exceesed 1/16 inch in this lateral directioit, the resulting constraint of tne pipe was nut considered in the piping analysis, i
1 The SMC resolutten rethodology is to consicer U bolts as two way restraints Thc staff eve 16ation of this issue is ciscussed in Sectici, ; of this appendia,
{
3.4 Pine /Suecort Cleerences <
f l
ESIS 8-C13 (Attacomer,t A to DAP-E P-013).The issue tackgroun The SWEC resolution mathecologf :s previded in CPPF-7. Attachment 4-11.
The CAP evaluation is previdec in Encireering Evaluation DAP-E-P 013 (section S.5.2) and is sussarized in tN piping results repcrt (Section 3.2.3.13).
The =rtrary concert (uc to 3/16 ince) were less conservative than clearances commo ircustry tractice (1/W inch).
The SWEC approach establishes a maximuni cisarance between the pipe anc rigic frame type support of 1/8 inch in the act cor41 tion ano a rtinimum clearance of 0.01 inch in the hot condition.
cleararcas are provised in the cold position to facilitatA inttallatten anc ine very witn tat stze of the pipe ano the temperature. 7 f#1adettnatthel SWEC.,9,1 Cofmc4 heet.with DI fBafl '
,_. m a 13.! CenC14sica gg6 att 3
o f1 havs e re; etevFfte 195t99,e generic t
'issut conterstag gaps is, the 14 SE:SMIC DESIGN l.QA0 SPECIFICATIOM Several issues concerning the seismic analysis of CPSES piping syttens previously performed by Gibbs & Hill, incorporatea, were raised.
The CPiti intec-part.y ;TE.NERA. L.P.) tdentified 17 related concerns from varicus s w :e
.....4.
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- ENCLOSURE TO TXX-93024
~
1 M',CHMX W A_
5 :' :, l M.s PAGE 16 0F 17 CALC No 2-N9+EWV-STI n !_Q _
4 In F$AA Sect 1'on 3,33.3.$. the applicant has described more transtant analyst hydraulic forces s methods used by SWEC.
a the fluid previously calculated usir.g a facter approach - are computed directly by $WEC analysts methods.
pipe support fer each straight run of piping Secondly, rather.than provtstag previously comitted. $WEC determines the nee,d for a pipe suppo 14 which the applicant had transient loadings by dynamic analysis methods and elimin t or fluid supports.
In addition for open discharge pising systemsa es enmecessary used is in confomance,with Appendix 0 of AM Code Sectio,n !!! (n The staff's review of fluid transient analysts methods is pmvid d to this supplement (Section 18.
erence 40).
technically Adequate and consistent with the asel$W e
n Appendix A pproach is other nuclear factitties and is thus acceptable. ysis methods used by SWIC for A$ME Code Class 2 and 3 pipitul.In Table 3.99-13. the loading been rav1 sad to describe the "cading combinations used by $W rovided for design validation.
conditions and themel anchor movements.The normal condition n the piping to include thermal anchor movements.The upset condition has been revised The emergency condition has been revised te d,tlete the $$t as previously discussed.
displacements, and $5E anchor movements. expanded to includ The faulted condition has been the exception of celeting the $$E from the emergency conditiThese charg n
conservative loading combinations than those that were previous on) result in more anc are thus acceptable.
ered In Apoendix 38, the applicant has provided a description of the c and the vertf tcation methods used by $WEC in the piping design ceputer codes codes have been used by $ Wit for other nuclear facilities.
ano evaluation of the computer code methods of verification are pro on.
All The staff's rev tew Appendix A to this supplement ($ection 29) v ed in On the basis of its review of FSAR AmendumM 61 (
the revised criterta related to piping and pipe support d the staff finds Amendment 61 including the use of later ASME Code provisithe hA-114 esign, provide.1 fn FSAR ons as discussed in satisfy the applicable provisions of 10 CFR 50.554 as qualified abov e erem:e 27),
are thus acceptable.
. and Review of pisina Desien Criteria The piping design criteria for Cp$t$ Units 1 and 2 are docu (Reference 30) and project meeoranda (AppeMix E of this s mented in CPPP-7 piping and supports at CP3E3 Units 1 and 2 is in a upplement). The comettaents and the applicable ASME lotler and Prwssure Vessel Co e
censing requirements (Reference 27 and 28).
The staff's evaluation of t criteria consisted of reviews and audits in the following areas:he desig ACCEPTABl{15tARGINAL QUALITY IkilT-DATE 3 * @
l
(
/d Comanche Pesk $5ER 14 4-10
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l TNCLOSURE TO TXX-93024 PAGE 17 0F 17 ATTACHMENT No 1
Fats 2 y 1 CALC No 2-W-6 EM-fri m o
I (1) r$AA chentes to reflect reviscd design criteria-i
(?) casign criteric partaining to the resolutitn of generic technical j
issues as incorporated in CPPP-7 h
Q) - third-party actions relative to the detailed review and evaluation j
of the design criteria j
(4) overall adequacy of pipe stress design criteria The staf f's review and evaluation cf. the piples design criteria in the CPSES FSAR (up to and including Amendment 60) art discussed in the CPSES SER ano supplements (up to and including Sugg W ent 12). The staff's review and evaluation of Amendment 61 to the FSAA - which included changes to reflect the revisee piping design criteria applicable to the CAP desip validation effort -
are discussed in the previous section of this supplement. Subsequent-changes l
to piping design criteria -that may affect F5AA-licensing camaitments or, the t
bases of staff evaluations contained in its SER and supplements shall apoear 'in future FSAA amenements, and staff evaluations of those changes will be proviceo in future supplements to the SER~.
l The staff in--its review of the piping design criteria for resolving generic technical issues conductad ~several design audits.- (See Appendix 0 to this susolement - Events 11. 17. 18. and 31.)
tnc staff vers developed by SWEC in part to address the generic technica I,
issues applicable to oiping and pipe supports 'at CPSES. The staff review arc l
evaluation of the-piping design criteria-pertaining to the resolution of
(
generic technical issues as incorporated in CPPP-7 are discussed later in tnts l
section ano ss,ecifically in Appendia A to this supplement.
(
The sta'f's' review and evaluation of-thel third-party (TENERA) activities l
Associated vista the review of the piping design criteria are discussed in l
Section 4.2.1.
i The staff reviewed the overall technical adequacy of the pfpe-stress easien r
l criteria in CPPP-7 (Referer.ca 30). As part of its design audtt, the staf f
~
[
reviewoo tne bases for selected eesign criteria and their applicability to CPSES (see Appendia 0 to this supplement - Events ~35 and 37).
i As a result ef-'
l its audits.: the staff finds that the CPPP 7 desip criteria for pipe-stress analysis provide adeteste guise 11nes to ensure that the desty of ASE Code Class 2 and 3 piping systems satisfies-the design requirements of ASME Coce.
j.
Section III, Subsections NC and NO (Anference 27) and are tAus acceptable.
i On the Jasis of its review of the CPpP-7 desip criteria (Reference 30), the i
staff finds that the criteria provide adequate-technical guidelines for the-resolution of generic technical issues and for ensuring that the applicable
' piping and pipe support design requirements of ASE Cede. $ection !!!
-(
References:
27 and 28) and-Itcensing commitments art satisfied and are thus acceptable.
t l
ggnericTechnical' Issues The generic technical tssues are those desigst concertis identified by sources external to the TU Electric organization that potentially affects more than : -
Comanche Paak SSER 14 4-11
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