ML20127M070
| ML20127M070 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/21/1993 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-93037, NUDOCS 9301280100 | |
| Download: ML20127M070 (16) | |
Text
w Wess 1- -
Log # TXX 93037 Z
~~
~~ File # 10010 903.7 7UELECTRIC Ref. # 10CFR50.34(b)
January 21, 1993
% illiam J. Cubill. Jr.
tho.op h a brudent U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) -
UNIT 2 DOCKET NO. 50-446 ADVANCE FSAR SUBMITTAL SEISMIC CATEGORY 11 PIPlHG AND SUPPORTS LOCATED IN A NON-CATEGORY I BUILDING REF: 1) NUREG 0797, " Safety Evaluation Report," Supplement 22 (SSER 22)
- 2) TV Electric letter logged TXX 92063 f rom William J. Cahill. Jr., to the NRC dated March 4, 1992 Gentlemen:
Attached is an advance FSAR change to reclassify a portion of die eight (8) inch Heater Drain piping and one pipe support in the Turbine Building from non-seismic to seismic Category !!. This change permits one seismic pipe support to be located thirteen inches inside the Turbine Building. This seismic pipe support is a seismic /non seismic anchor for a seismically qualified non ASME, high energy Heater Drains piping system.
The reclassified portion of the Heater Drains piping and subject pipe support are completely supported by a Seismic Category I wall which separates Room 113 from the non Category 1 Turbine Building. An analysis and an engineering evaluation have been performed which demonstrated that the Turbine Building will not have unacceptable interactions with the reclassified piping during and after a seismic event.
The attachment is organized as follows:
- 1. A marked up copy of the revised FSAR pages (additional pages immediately preceding and/or following the revised pages are provided if needed to understand the change).
- 2. A description / justification of each FSAR change.
- 3. A copy of related SER/SSER sections.
2501090 i 93 1280100 93 7 m o,o12,1,, oo _. s __ , . e. . . . _ eg PCR -
TXN93037 Page 2 of 2 This change will be included in a future FSAR Amendment. If you have any questions regarding this submittal. please contact Mr. Carl B. Corbin at (214) 812 8859.
Sincerely, William J. Cahill, Jr.
By:g J. S. Ha/shall Generic Licensing Manager CBC/tg Attachment c- Mr. J. L. Milhoan, Region IV Resident inspectors, CPSES (2) l g, -
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+
4 Attachment to TD-93037 Page 1 of 14 Attachment to TXX-93037
- 1. Marked up copy of FSAR pa90s pages 2 through 7
- 2. Description / justification pages 8 and 9
- 3. Related SSER sections pages 10 through 14 B
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' -- __-___m
Attachment to TXX-93037 Page '2 of 14 CPSES/FSAR
- 35. Miscellaneous Handling Equipment 52
- 40. Plant Gas System , 7
- 42. Tornado Venting Components 7
- 45. Potable and Sanitary Water System 12
- 49. Pipe Whip Reetraints 12
- 51. Uninterruptible Power Supply (UPS) Area Air-Conditioning System 66
'l 3.2.1.1.3 Seismic Category I Electrical Systems and Components 7 All, or portions, of the following electrical systems or components 7 are seismic Category I as described in Appendix 17A and Table 17A-1:
i 17A SYSTEM 7 NO. SYSTEM 7
- 37. Electrical Equipment 7 i
- 38. Radiation Monitoring System 7
- 41. Instrumentation and Control Equipment 7 3.2.1.1.4 Structures and Systems of Mixed Category None of the plant structures are classified as partially seismic 59 Category I; however, certain structural items within seismic Category I structures are classified as seismic Category II or non-seismic as appropriate. See Table 17A-1, item 36, for typical structural classifications. The boundaries of seismic Cate00ry I portions of
- systems are shown on the piping an_d ins on_ diagrams i_n appropriate sections of the FS[ eismic category II p4pe located 85
- inside a non-seismic building % described in Section 3.2.2.d.
cve pipin3 seyents 3.2-5 Amendment 85 May 29, 1992
Attachment to TXX-93037 Page.3 of 14 O CP ES/F AR S ecd 66 349nwnTS > Which Crt IST!In fW 85 C4 pertjen of th; Stearm0cncr:ter 910=dcun igh energy 1 h0 - /
piping [locatedintheTurbineBuilding$designatedclass J 5 piping and classified as seismic Category !!, .TMt These pipingMsksNca'11[analyzedforbreakpostulationfAnd56*rmic 4
Additional anal ses are performed to demonstrate that UdM"Don.
soinsents
, und ecpfab/s interactions of piping 3with non-Category I structures / components will not occur durin g a seismic h
66 Class 5 lines, which are determined as not reducing the
- functioning of the systems and components described above to an unacceptable degree, and Class G lines are fabricated and installed in accordance with applicable industry codes I
and standards.
12 All, or portions of the systems or components that are Seismic Category !! are described in Appendix 17A and Ta'ule
+
.. 17A-1, 66 3. Radioactive Waste Management System (RWMS)
The RWMS designation is used to identify the boundaries ofthe radioactive waste management system on applicable CPSES flow diagrams, as the RWMS does not match the functional e
Amendment 85 3.2-12 May 29, 1992
Attachment to TXX-93037 ,
Page.4 of 14 CPSES/FSAR 3.78.2.8 Interaction of Non-Cateoory I Structures n
with Seismic Cateaory I Structures M A number of structures such as the Turbine Building, the Switchgear b N Buildings, the Circulating Water Intake and Discharge Structures, the R Q. Maintenance Building, and the Administration Building are designated
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, 6 k j $ as non-Category I.
il %EQ 4 o :
L i l The only non-Category I structures which are adjacent to any seismic Category I structure are the Turbine Building and the Switchgear oOD Buildings. These structures do not share a common mat with the k* adjacent seismic Category I structure, and all structures are founded I on firm rock. Therefore, there is no possible interaction of non-
- g. y 0 Category I structures with seismic Category I structures resulting
?. g from seismic motion. Sufficient space is provided between the Turbine
,g k g@ and Switchgear Buildings and the adjacent seismic Category I structure y {\> so as to prevent contact because of deformations occurring in the structures during a seismic event.
C The possibility of structural failure during a seismic event is 78 considered for the Turbine Building. Structural failure in the direction of the adjacent seismic Category I structure is prevented by the bearing of the mezzanine and operating floor slabs on the concrete turbine generator pedestal. The Switchgear Buildings are design to withstand a seismic event equal to the high eng&y pipIn3 S tjM&ffS AICh 85 The seismic Category II ~. Men ei A L ea Ceauetcr Sicudcun u @
l cre;y "c (S-SS 2 000 1202-5} located inside the Turbine Building, f ar i j and attached to a seismic Category I structure % eshown by analysis to remain undamaged by non-Category I structures and components during a
{\
ent. The piply $dym0$$ ighlVid Ord : 4
~ A __ 4 __ # g 54 Non-Category I equipment and components located in seismic Category I buildings are investigated by analysis or testing, or both, to ensure that under the prescribed earthquake loading, structural integrity is maintained, or the non-Category I equipment and components do not adversely affect the integrity or operability, or both, of any Amendment 85 3.7B-42 May 29, 1992
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CFSES/FSAR 7 ,'>
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TABLR 17A-1 El r*
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-% 3 f.IST OF QtRLITY ASSURED $71tUCTUltES. SYSTEMS ADO CCD@00ENTS <*
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,A I Appliamble q -
Safety Code or . Code Seimmic Quality Reference >c.
e Sv-tese and Comento - Class (7) ' Star.dard (121 Class Category Assurance Section Remarks 4.0 w
O Check valves for accumuistor tanks 3 ASBs III 3 I Mote 32,A 10.3 Note 79 W l~33 i i
}
N Q260.1 l 33 l
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4 3 AsDa III 3 hte 32,A 3.98 hte 41 8
C 1 Tubing and supporte (between check I l68 i
t 1... . tre_ .,.ir a _ .1.t.r l..
and Aov) l6e
-2 Ases III 2 Note 26,A 10.3 ste== generator blowdown I l68 {" l syst _ piping l68 ste_ flow restrictor (integral to 2 ASBS III 2 I Note 4,A 10.3, 5.4.4 lQ212.71 steam generator)'-
l6a Main steam isolation valves 2 Asia III 1 I Note 26,A. 10.3 mt.o e, 79 ~!
l es 0260.1 l e3 Nain steem isolation brp*** 'al'*e 2 Ases III 1 I Note 26,A 10.3 Notee 8, 79
) 83 I and bype.. valve piping 026o.2 l es .d m.._ m e.
5 fie.u .e in..ua uan fr. . d. - II ot. n,. 6.2.2 6.
Piping and valves ' 2 ASDS III 2 I Note 26,A 10.3 Nte 79 l 33 0260.1 l es Piping and valves : 3 Asps III 3 I Note 26,A 10.3 05ote 79 l 83 Q260.1 l e3 .Q Orifices 3 ASIS III 3 I h ee 26,A 10.3 l..
l6e
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-f supports for Class 2 Piping 2 Ases III 2 Note 27,A 3.9a I
l6e swa for Clam. 3 tiping 3 Ases III 3 Note 27,A 3.9s I
l6e Claas 5 eiptag and su m s. ne S AstSI S31.1 -
II/ NOME asote 44,5 3.7s mte 31 l 85 ,
- 13. Auxiliary Feedwater System Motor-driven an=414 ary feeenator pumps .3 ASDS III 3 Note 26,A 10.4.9 I Isote la l68 Turbine-drivoa anu tiary feedwater pump 3 3 Note 26,A 10.4.9 Note le
. Asia III I f68 AMENOWPENT 45 MAY 29,1992 ,
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CPSE3/FSAA M mia 172-1 (Sheet 50) 3>
LIST OF CWLLITY ASSURED STRUCTURES. FTSTEIGB AIO CfDeOtRafTS I f 55 gh 3 '
O fD
%D Appliamble c+ ,
a Safety Code or Code Seimmic Quality Referemoe D{ i Sv-tesa and C e ents class (7) Standard (121 Class Category Assurance Section Panarks y X
- b. Refrigerant paping a tubes 3 ASTM B42 Note 26,A Fig. 9.4-15 Note 21 I
l64 A32M B.. i.ote 27, 50,A l 76 $
C
- c. Water Side 3 A$ta III 3 I Note 26,A Fig. 9.4-15 03 lGe N Dempers and supports 3 Mfra stds Note 26, 32,A Fig. 9.4-15 Note 21 I
l66 Ductwork and supports 3 Nfra Stds -
I Note 26, 32,1 Fig. 9.4-15 Nate 21 l64 Boostar Return Fans 3 Mfr> Stds -
I Note 26,A Fig. 9.4-15 Note 21 l68
- 52. Turbine flant coolinq l 87 m e.r S .ee.
l.7 Class 5 piping and supports HMS ANSI B31.1 II/ Nome Note 44,3 10.4.12 l 37
- 53. Condensata Polishing Syst==
l e7 Claae 5 piping and supports eBf3 ANSI B31.1 12/None Note 44,3 10.4.6 l 87
- 54. Condenser vacumma and l37 htection Primiro S, stem l87 Class 5 piping and eurports letS ANSI B31.1 II/None Note 44,8 10.4.2 l87
- 55. -Be ster Drains 9-est ess l 37 Class 5 p ping and supports NNS AntSI B31.1 II/ Nome Note 44,3 10.4.11 ofO 8i l e7
- 55. chemical Feed systa=
l87 Clasa 5 piping and supports sets ANSI B31.1 II/Nme Note se,B Fig. 10.3-1 le7 i F
- 57. Security Systems l83 Barriers / doors N/A Mfra Stds - NCEFE Note C 13.6 33
] Intrusion Detection / NIE Mfzs Stds -
te0NE Note C 13.6 l 33 Monitoring l 83 Lighting NIE Mfra Stds - NCMrE Note C 13.6 l 83 Access Control System NIE Mfra Stds -
NCelt N >te C 13.6 Am .dment 87 l 83 Deessaber it, 1992
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FT ED Os CPSES/FSAR .O n .r.x 17A-1 . C 5
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0 LIST OF OtRIA""! .SSUPJtD sirwivraS, SYSTEMS APO cG1POf.ff"S g x
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.hri=Tahl. c.bi. to.ul.tio. 1 .. .r. ,rocur.d d their .oci.t.d in.t.11.tio. requir .ct. ...ur. th t r functic.ning f211 wing e p.i.mrc- -
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ore
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.s . ry, u ,1,1. a1 . 4 to es. ro,si .,mioio, - a..i t.4 1 . , ,1,i., . wc1 .i,1 4 l .3 416 sei to c.t gory II .... thou,n the loo.tioi a.re un n>r J41. . .o.- i ie buildi.g. Adiitio 1 41y... .r. p.1for d to d o tr.t. th.t i t.z of s as .5
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.2. Pipi.g ..d .upport, for th. Di..el c er. tor .zh.umt pipi.9 th. buildi g, fra tb. fl.z1bl. co .etor. to ju.t up.tre of th. .e.s.u.t r.11.f l ..
. 1.., . a..i .a. 11 4, i....u.4 a io e.4 to ts. r.2u, .t. o, m. etio. xxx, aa.ai , coa. c. -253-2. 1. ._. o, u. ,_,. l eupport qu=12 ficatio.., part of th. t.ri.1 str... .no..ht.. .r. .atr.cted fr= Ansi m31.1. I. n e .., th. r.q.ir t. of cod. c .. w-253-2 l
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l AMENDMENT 85 MAY 29,1992
i CPSES - FINAL SAFETY ANALYSIS REPORT (FSAR) 1 Attachment to AMENDHENT / REVISION 88 TXX-93037 DETAILED DESCRIPTION Page 1 l
' Page 8 of 14 Prcfix Page (n Amended) GrAup lluntlplion 3.2-5 1 Revises discussion of Structures and Systems of Hixed rategory.
Asvision :
Revises sentence to indicate that there is more than one Jeisr.ic Category 11 piping segment located in a non-seismic building.
Change Request Number : SA-93-4.1 Commitment Register Number :
Related SER : 3.2 SSER :
SER/SSER Impact : No 3.2-12 1 Revises discussion regarding piping segments located in the Turbine Building which are designated class 5 piping and classified as seismic Category II.
Revision :
Changes discussion to indicate that there is more that one piping segment located in the Turbine Building which is designated class 5 piping and classified as seismic Category II. The applicable piping segments are listed in Section 3.78.2.8. Also clarifies that these piping segments are analyzed for seismic qualification and unacceptable interactions with non-category I structures /compenents.
Change Request Number : SA-93-4.2 Commitment Register Number :
Related SER : 3.2 SSER :
SER/SSER Impact : No 3.78-42 1 Revises discussion of Interaction of Non-Category I Structures with Seismic Category I Sturctures.
Revision :
Adds the specific exception concerning the Unit 2 Heater Drain line piping in the Turbine Building.
The Heater Drain piping has been reclassified as Class 5 and redesignated as Seismic Category II to allow the placement of a seismic /non-seismic boundary anchor of a seismically qualified high energy Heater Drains pipe line thirteen inches inside the Turbine Building. Analyses have been performed that demonstrate that the non-Category I structures and components within the Turbine Building will not unacceptably interact with Heater Drain piping during and after a seismic event.
Change Request Number : SA-93-4.3 Commitment Register Humber :
Related SER : 3.7 SSER :
SER/SSER Impact : No Table 17A-1 1 See Sheet No(s) :50
. Add Note 81 to List of Quality Assured Structures.
TXX-93037 AMENDMENT / REVISION 88
- Page 9 of 14 ,
DETAILED DESCRIPTION Page 2 1
PrGfix Page (Al Adended) Group Description 4
Revision :
The specific exception concerning the Heater Drain piping in the Turbine Butiding has been-added to d
Table 17A 1 via Note 81. The quality assurance
, requirements for this piping will be the same as-for 4 any Class S. Seismic Category II piping'except that the piping is not located-in a Seismic Category I
. structure.
Change-Request Number- : SA-93-4.4 i Commitment Register Number-:
! Related SER : SSER :
. SER/SSER~ Impact : No i Table 17A-1 1 See Sheet No(s) :60' 4
Revises Note 81 to. List of Quality Assured Structures,
{
Systems and Components.
Revision :
Revises note 81~to indicate that there is more than one piping segment located in the Turbine Building which is designated class-5 piping and classified as' Seismic Category II even though' located in a non-i seismic-building. The applicable piping segments are listed in Section 3.78.2.8.-
Change Request Number. : SA-93-4.5
- Commitment Register Number
Related SER : SSER :
SER/SSER Impact : No
]
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7.._________..__
, n y A'ttaghment to TXX-93037 j_ Page 10 of 14
[
L i-I 3 DESIGN CRITERIA FOR STRUCTURES, SYSTEMS, AND COMPONENTS
' 3.1 Confomance With General Design Criteria and NRC Regulations l
In Section 3.0 of the FSAR, the applicant presented an evaluation of the '
! design bases against the G00. In a letter dated February 20, 1981, the NRC staff asked the applicant to provide a compilation which documents-that the i
Comanche Peak Steam Electric Station Units 1 and 2 will comply with the l regulations given in 10 CFR Parts 20, 50, and 100. The applicant has not i responded to this request for information and this matter remains an open L issue.
The staff review of structures, systems and components relies extensively on-theapplicationofindustrycodesandshndardsthathavebeenusedasaccepted l
, industry practice.- These codes and standards, as cited in this report. have l
been M viewed and found acceptable by the staff, and they have been incorporated
! into the SRP.
1
! 3.2 Classification of Structures, Systems, and Components I
j 3.2.1 Seismic Classification l GDC 2, in part, requires that nuclear power plant structures, systems, and j components important to safety be designed to withstand the effects of earth-
- quates without a loss of capability to perform their safety function. These i plant features are those necessary to ensure (1) the integrity-of the reactor -
i coolant maintain pressure boundary,condition, it in a safe-shutdown (2) the capability or (to shut down the reactor and mitigate the consequences of accidents which could result in potential =offsite l
exposures comparable to 10 CFR Part 100 guideline exposures. The earthquake j
for which these plant features are designed is defined in 10 CFR Part 100,-
Appendix A as the safe-shutdown earthquake (SSE).
The SSE is based-on an evalua-tion of the maximum earthquake potential and is that earthquake which produces- .
i the maximum vibratory ground motion for which structures, systems, and components important to safety are desinned to remain functional. Those plant features.that 5 are designed to remain funct'onal if an SSE occurs are designated seismic i Category I in Regulatory Guide 1.29. This Regulatory Guide is the principal i
document used in the staff review for identifying.those plant-features important i
to safety which, as a minimum, should be designed to seismic Category I require-i ments. The staff review of the seismic classification of structures,isystems,
.and components -(excluding electrical features) of Comanche Peak Units 1 and 2 !
was performed in accordance with the~ guidance in SRP Section 3.2.1.- ,
L The structures,. systems, and components important to the safety of Comanche i J Peak that are required to be designed to withstand the effects of an SSE and l i remain functional have been ident< fled in an acceptable manner in Table 17A-1 i
of the FSAR. _ Table 17A-1, in part, identifies major components.in fluid i systems, mechanical systems and associated-structures designated as seismic-l Category I. In addition, piping and instrumentation diagrams in the FSAR -
i-3-1 r
i j-
+
a ,
4- httachmenttoTXX-93037 .
j Page 11 of 14 l
identify the interconnecting piping and valves and the boundary limits of each
- system classified as seismic Category I. The staff has reviewed Table 17A-1 i and the fluid system piping and instrumentation diagrams and has concluded i that the structures, systems, and components important to safety of Comanche Peak Units 1 and 2 have been prope 1 classified as seismic Category I items i in conformance with Regulatory Gui 1.29, Revision 2 In the review of f Section 3.9 of the FSAR table interfaces exist j between seismic Category, I andthe staff confirmed nonseismic portionsthat of acc iping systems, All 4 other structures, systems, and components that may be required for operation ;
j of the facility are not required to be designed to seismic Category I. require- !
j ments. This exclusion includes those portions of Category I systems such as '
vent ifnes, fill lines, drain lines, and test lines on the downstream side of
! isolation valves and portions of these systems that are not required to perfone l
t a safety function, i
The staff concludes that the Comanche Peak structures, systems, and com>onents -
! important to safety that are designed to withstand the effects of an SSE and remain functional are proper 1 classified as seismic Category I items in
- accordance with Regulatory G de 1.29. This constitutes an acceptable basis ,
i' j for satisfying, in part, the requirements of GDC 2, and is, therefore, acceptable.
3.2.2 System Quality Group Classification GOC 1 requires that nuclear power plant systems and components important to i safety be designed, fabricated erected, and tested to quality standards j commensurate with the importanc,e of the safety functian to be performed.
l These fluid-system, pressure-retaining components are part of the reactor i coolant pressure boundary and other f uid systems important to safety, where i reliance is placed on these systems: (1).to prevent or mitigate the consequences L of accidents and malfunctions originating within the reactor coolant pressure i boundary, (2) to permit shutdown of the reactor and maintain-it in a safe-
! shutdown condition, and (3) to en ain radioactive material. -Re ulatory Guide 1.26 I
is the principal document used in the staff. review for. identify ng, on a functional basis, the components of those systems important to safety that are Quality Groups B, C, and D. Section 50.55a of 10 CFR Part 50 identifies those American Society of Mechanical. Engineers (ASME) Boiler and Pressure Vessel Code Section III, Class I components that are part of the reactor coolant >
pressure boundary (RCPB). Conformance-of these RCPB components with Section 50.55a !
of 10 CFR Part 50 is discussed in Section 5.2.1.1 of this re rt. These RCPB components are designated in Regulatory Guide 1.26;as Quali Group A. Certain other RCPB components which meet the exclusion requirements of footnote 2 of
.the rule are classified Quality Group B in accordance with Regulatory Guide 1.26. ;
The staff review of the quality group classification of pressure-retaining <
components of fluid systems important to safety for Comanche ~ Peak Units 1.
and 2 was performed in accordance with the guidance in SRP Section 3.2.2. [
FSAR Table 17A-1 in part identifiesthemajorcomponentsinfluidsystems such as pressure, vessels,, heat exchangers, storage tanks, pumps piping,.and-valves, as well as~ mechanical systems such as cranes, refueling p,latforms, and.
other miscellaneous handling equ poent. In addition,1the pi ng and instrumenta-tion diagrams in the FSAR identi y the classification-bounda es of the inter-connecting piping and valves. The applicant has utilized the American Nuclear 3-2
? [h
5 Attachment to TXX-93037 Page'12 of 14 Based on the review described above, the staff concludes that the applicant
- has not met the requirements of GDC 4 regarding' pipe breaks. The staff will
- j. provide the resolution to the open items described above in a supplement to this report.
3.7 Seismic Design
]
i 3.7.1 Seismic Input
! The input seismic design response spectra (operating-basis earthquake (OBE)
- and safe-shutdown earthquake (SSE)) applied in the design of seismic Category I structures and components were developed from numerous real records, following the procedures recommended _by Newmark, Blume, and Kapur* and conform to the requirements of Regulatory Guide 1.60, Revision 1, with the exception of those
, in the 33-Hz to 50-Hz frequency range. In this range, the vertical response-spectrum of Regulatory Guide 1.60. Revision 1, differs from the vertical i response spectrum used by the applicant. Because this deviation only affects the modes that have low amplification, the effect of this deviation on the l results of the analyses of structures and systems is negligible. Similarly, the method recommended by Newmark and his colleagues for the construction of vertical response spectra leads to a slight deviation from the Regulatory 4
Guide 1.60, Revision 1, recommendations for accelerations corresponding to 3.5 Hz. The magnitude of these differences is negligible.
The horizontal and vertical design response spectra are scaled to the maximum 3 ground acceleration of 0.12g and 0.08g selected for the SSE. For the OBE, a scaling factor of 0.5 is applied to the SSE design spectra. The site design response spectra are applied at the various foundations of seismic Category I structures.
! The specific percentage of critical damping values used in the seismic analysis of Category I structures, systems, and components is based on material, stress '
levels, and type of connections of the particular structure or component. ;
These values are determined in accordance with the recommendations of Regulatory Guide 1,61 and those in Newmark's work. The synthetic time history used for the seismic design of Category I structures, systems and components is adjusted in amplitude and frequency content to obtain response spectra that enveloped l_
the response spectra specified for the site.
3.7.2 Seismic Structural System and Subsystem Analyses 1
The review of the seismic system and subsystem analysis for the plant included the seismic _ analysis methods for all Category I structures, systems, and components, in addition to procedures for modeling, seismic soil-structure 4
interaction, development'of floor response spectra, inclusion of torsional effects, evaluation of Category I structure overturning, and determination of composite damping. The review included design criteria and procedures for evaluation of interaction of non-Category I. structures and piping with Cattgory I
"" Design Report Spectra for Nuclear Power Plants" presented by N. B. Newmark, J. A. Blume, and K. K. Kapur, at the ASCE Structural Engineering Meeting, San Francisco, April 1973.
3-14 h
>h
E kI httachment to TXX-93037 1
Page 13 of 14 structures and piping and the effects of parameter variations on floor response spectra. The review also included criteria and seismic analysis procedures for reactor internal and Category I buried piping outside the containment.
The system and subsystem analyses were performed by the applicant on an elastic
. basis. Modal response spectrum multidegree of freedom and time-history methods form the basis for the analyses of all major Category I structures, systems and components, When the modal response spectrum method is used, governing response parameters will be combined by a method that is generally more con-servative than the square-root-of-the-sum-of-the-squares rule adopted as the staff position. However, the absolute sum of the modal response was used for modes with closely spaced frequencies. The square root of the sum of the squares of the maximum codirectional responses was used in accounting for three compor.ents of the earthquake motion for both the time history and response spectrum methods. Floor spectra input for design and test verification of structures, systems, and components was generated from the time-history method, taking into account variation of parameters by peak widening. Peaks were broadened i 10% and connected without leaving valleys. When the peak broadening is less than i 15%, the smoothing method is conservative and acceptable. A vertical seismic system dynamic analysis was employed for all structures, systems, and components where analysis showed significant structural ampli-fication in the vertical direction. Torsional effects and stability against overturning were considered. The applicant has demonstrated to the staff that the eccentricities used in the analysis of Category I structures for the evaluation of torsional effects exceed the minimum value of i 5% recommended
, by the staff. The staff finds the eccentricity values considered in the design acceptable.
The lumped-mass-spring approach is used to evaluate soil-structure interaction and structure-to-structure interaction effects and seismic responses.
For the analysis of Category I dams, a finite element approach that takes into consideration the time history of forces, the behavior and deformation of the dam caused by the earthquake, and applicable stress-strain relations is used.
The staff concludes that the seismic system and subsystem analysis procedures and criteria proposed t'y the applicant provide an acceptable basis for the seismic design.
3.7.3 Seismic Mechanical Subsystem Analyses The review under SRP Section 3.7.3 included the applicant's seismic analysis of the reactor coolant system; reactor internals, core, and control rod drive mechanisms; and seismic Category I piping systems (excluding the reactor coolant system). Each of these areas is discussed below.
3.7.3.1 Reactor Coolant System The reactor vessel, pumps, steam generators and their supports, end the inter-connecting piping system were evaluated as a coupled system. The mathematical model provides a three-dimensional representation of the dynamic response of the coupled components to seismic excitations in both the horizontal and 3-15 n
Attachment to TXX-93037
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l 3.7.2 Seismic Structural System and Subsystem Analyses FSAR Figures f.73-41 through 3.78-49, documenting response spectra, were deleted from the FSAR. In the August 16, 1989 submittal, the applicant confirmed that these spectra were not used for design of any Category I structures. However, in a letter dated January 3, 1990, the applicant committed to include sample base and top level response spectra used for the design of the CPSES Category I structures in a future FSAR revision (Amendment 78) prior.to Unit 1 fuel loading.
This issue is considered resolved, contingent on staff verification that the 4
appropriate FSAR changes are made before Unit 1 fuel loading.
. The applicant has agreed to revise the FSAR to document that the peaks of the floor response spectra were widened by 110 percent rather than by only +10 per-cent. The applicant will also revise the FSAR to reflect that the effect of the structural backfill on the soil spring stiffness values for the service water intake structure (SWIS) was calculated based on rock and_then for soil media, and that average spring stiffness was used. The staff reviewed relevant docu-ments during the site audit on September 6-8, 1989. The results of the para-metric study performed for the generation of the floor response spectra were also discussed during the audit. The parametric variation of the soil-spring stiffness had been considered in generating the original floor response spectra.
The validation study considered the soil-structure interaction by modeling the soil along with the foundation, The CLASSI and FLORA computer programs were
, used in this validation process. The parametric variation was not considered for the new response spectra used for validation purposes. However, for the SWIS and three exterior storage tanks, new response spectra were developed considering the parametric variation. In addition, the staff verified that an average value of soil-spring stiffness between rock and soil redia was used in the calculations for response spectra for the SWIS. The staff finds these
- approaches to be acceptable.
The FSAR did not include a discussion on the method of analysis for Category I tanks. In the meeting on July 31, 1989, the applicant agreed to revise the FSAR to provide such a discussion, including irformation related to the geometry of tanks at CPSES. The August 16, 1989 submittal provides the information_re-quested by the staff. This information is also in FSAR Section 3.8.4.1.6. This information describes the' method of analysis which complies with the provisions i of U.S. Atomic Energy Commission Technical Information Document TID-7024, and is acceptable to the staff.
! FSAR Amendment 68 stated that the structural failure of t'he turbine building is prevented by internal bracing. During the meeting with the staff on July 31, 1989, the applicant stated that-the structural failure of the turbine building is prevented by-the bearing of the mezzanine and operating floor slabs on the concrete turbine pedestal. The applicant has revised FSAR Section 3.7B.2.8 to reflect the actual support mechanism for the turbine building. During its site visit on September 6-8, 1989, the staff reviewed the assumptions and methods used in the development of the loads on the support mechanism for the turbine building, and concluded that the analysis had been performed correctly. The
, staff, therefore, considers this issue to be resolved.
The applicant has. revised the FSAR to include missing terms and the definition i
of two analysis parameters in Sections 3.7N.2.1.2 and 3.7N.2.1.5. Also,.since the power spectral density (PSD) function was not used to' characterize the input motios, FSAR'Section 3.78.2.1.3 has been revised to delete the term FSD. In Comanche Peak SSER 22 3-3 g * - m,-m- - - - - -y ,* e aw w e-y--