ML20138P050
| ML20138P050 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 12/20/1985 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | Noonan V Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20138P053 | List: |
| References | |
| SBN-911, NUDOCS 8512240266 | |
| Download: ML20138P050 (13) | |
Text
{{#Wiki_filter:- ( .
,o.
M SEABROOK STATION Engineering Office December 20, 1985 . OOdbO SBN-911 Mew Hompshire Yonkee Divlelon United States Nuclear Regulatory Commission Washington, DC 20555
-Attention: Mr. Vincent S. Noonan, Project Director PWR Project Directorate No.- 5
References:
(a) Construction Permits CPPR-35 and CPPR-36, Docket Nos. 50-443 and 50-444 (b) PSNH Letter (SBN-809), dated June 3, 1985, " Cable Raceway System Damping," J. DeVincentis to G. W. Knighton
Subject:
Seabrook Cable Tray Support Qualification P9ar Sir:
-Enclosed _is 'the Report on the Seabrook Station Cable Tray Support Qualification Program. The report describes our proposed program for cable tray support-_ qualification which is based on plant-specific full scale dynamic tests as described to your staff at a meeting in Bethesda on December 3, 1985.: At that meeting, we co= mitt'ed to provide this report for your review and approval.
Cable tray support design at Seabrook was previously accomplished through
.use of traditional analytical methods. The Seabrook specific methods had been reviewed by NRC staff on many occasions over the past several years.
Currently, no open items exist as a result of these reviews. The criteria was based-on extremely conservative mathematical modeling of tray support arrangements. This extreme conservatisn results'in'the design and installation of significant lateral and, axial bracing to react seismic loads. The. project made a decision to re-evaluate the need for continued installation of extensive lateral bracing, especially bracing designed only to react axial (along the major run of tray) loads as a result of having participated in the_ generic raceway dynamic test program conducted by Bechtel Corporation, and observing the true response characteristics of Cable Tray
" Systems [ Reference (b)].
v A dynamic test program was developed involving shake table tests of full-scale representative Seabrook-specific raceway support schemes. The
-tests were conducted at the same facility used for the Bechtel Program. The
,resulta of the. test program were extremely positive, with both lightly braced and ur.oraced configurations maintaining structural integrity at seismic input levels.which envelope all affected Seabrook support locations. The testing demonstrated subsrantial design margin in the tray arrangements actually g installed in the plant. [l AOD*.
P.O. Box 300 Sectxook.NH 03874 . Telephone (603)474-9521 8512240266 851220 PDR ADOCK 05000443 .
~
_____._._____o
^ - -~~ ~~-- --
- n .
. - - .r, ,
x 42 ywp; 0? g.. y . .
<^
, a~ , ' .
- n. w
' y' . .
-y:: ~,
. ' v. ~
;nF + : : .. ,q[_ - . 'f _ _ _- ,
;UnitediStates Nuclear, RegulatoryLCommission :
?'
[ IAttentions;;Mr._ Vincent:S. Noonan. Pa8e:2 ,
y;- 3 / ~ , 4
- p. '
=
)
"-mm
& > - m s . . ..
'Q N , fin; addition to lthe plant-specific ' dynamic tests, .we have' developed' ;
4?' ' ; . Irefised' analytical methods' utilizing plant specifici test ;results, and results . 1
'4'~ [Mfromithe'.Bechteligeneric1programsto: qualify _supportsnotboundedby. testing',
K?n sw ith traditionallcalculational methods.
~'
n -
~ . -
q; . y , . .. . . , , . . ';, ( ..2 We'also'ha'dian independent study of thelSeabrook! cable tray' support E a 4, s ~ . arrangements performed by EQE;Inc.,Laffira.which4 specializes intthe historicair .
' performance 1of various equipment that has-been subject to-past, earthquakes.
~
% . si- N(Attachment (1f Appendix:A)'.J EQE spent considerable 1 time at.Seabrook walking. ;
WQ
~
- down a substantial amount of cable ttray. . : Theylhave compiled an extensive data
,T'n " base' od cable ;trayistructural performance at sites;which have experienced L' D , , . earthquakes comparable:to the Seabrobk-SSE..'
a: .
'd.< -'
hTheirMonclusions' areas'follows:-
- x. f .1 . ~ , .
a.; Substantial margin exists between theias-constructed ;Seabrook1 cable - my _ s trays.and?those in the; experience data base. l - :.b.< 'Thecapa.cityiof1cabletraystosurvive'seismicloadsis'not
, ;' ' sensitive to detailsiof cable tray construetion or la'yout. .
/% description:ofour:compie't'eprogramwas=providedstoyourstaffand. T '
%9 2 Region (IpersonnelatLRegionI! Headquarters:onOctober 2,11985. -InLaddition,-
Lfi g s an ;NRC,(staff member.(witnessed L the third . set" of dynamic -: tes ts ' at ' ANCO :
<+
c..
' 4 1 Laboratories in October 1985. .
^1-1 ..
~g j Most,recently,la meeting was' conducted with NRC staff on December.3, 1985-to'discussidetails'of~o'ur' program." As'a result of that meeting,Lwe committed fto provide.the following:information which is containeddin:the' attachments:1 3
" 1~.1 1 Clarification,to severai t'echnical/programmaticLitems'which were ;
.: . - l 1 presented ~ at: thelDecember 3L meeting (Attachment' 3). . ;
7 s , m s 3' I 2'. ~ Marked-up copies of FSAR pages which are affected by this. program '
$ J -(Attachmentj2).=
k3 7 LThe progras report (Attachment 1)'. f, .
'Basediot th'e(above 7 and'your review of:our report, we'respectively request-
'1 'vo
.y.w : t::yecific" approval?of the following:- ~ ' '
Rg f~ ~ jlb ' That; dynamicitests as. described in, Paragraphs 3 and -4 of the
~
s - A 7 attached: final' report,;which^are consistent with' test requirements: Tof IEEE-344, = constitute a method:for~ directly verifying the-adequacy
~ ~
+
1 " me', _' lof.a percentage of. cable ~' tray supports at Seabrook.J ,
$[ > - ~
T. LUtilizatibasof rotat'ional;and translational stiffness values for i c.. support connections in' mathematical'models. 7 V 3...: Structural acceptanc'e criteria as defined in Paragraph 3.3 of the
~ Vattached report.'
, w +
_,2 ,. ;
. ) p x.
- -u E!i n D
~
A
.--._...~.--,-.-.,."
. . - -w - -- - - _ , _ , . . . , . - - . . . . _ _ . - _ , . , . . , _ ,
- p b,'
,, ~. . . . . . . .
- United' States Nuclear Regulatory Commission-
- Attention:- 'Mr. Vincent S. 7 Noonan , iPage 3-
~
~ ~
IThe calculational sethods which.we propose,to. implement have:previously
~
. ,. 1been' utilizedat other NTOL facilities.and approv'ed.by:NRC..' staff; Use of..
' these' improved' calculational. techniques.in no;way degrades.the--originally.. -
M -intended: safety margins in the cable tray supports.-- 30urLtechnical staff is available,!and we:welcome the opportunity.to
~
, ~
,. 1.3 .c discuss tiechnical~ det' ails of. our program atyour convenience.
So_as to assure ?':. 1 ., .;that;this iten does not' adversely. affect our construction' schedule,' we request! ~.
~ ~
J w your reply by! January 24, .1986.~ '^
~, m. -
, .m ,n Ve y.tr y urs, f ; .
John DeVincentis, Director
. Engineering and Licensing 4-5Enclosures1 -
Sec:t Atomic Safety-an'd Licensing Board. Service List V t
,v l% s - m %
p . , - b
/ i e r 4 r i A 4
. y. _
r b
=
h.
+ J'
.l .c _
'is v' * -' <
- _> qe s-
E- ,
. fci * '
- --E6 e #
-William S. Jordan, III Donald E.: Chick 1 Diane : Curran ,. Town Manager
- Harmon,(Weiss & Jordan Town of Exeter L ~ 20001' S., Stree t , l N.W.- 10~ Front Street
~ l Suite-430s Exeter, NH 03833 LWashington,-lD.C. .20009 Brentwood Board of Selectmen
" Robert G. l Phrlis : RED Dalton Road.
10f fice of ' the Executive Legal Director Brentwood, NH 03833
- U.SZ Nuclear Regulatoryf Commission ~
Washing ton, J DC '20555 Richard E. Sullivan,- Mayor
. , . City Hall ~
LRobert ' A.: Backus,4 Esquire' Newburyport, MA 01950
'116 Lowelli Street - ~
P.O. Box 516 Calvin A. Canney Manc hester, NH 03105 City Manager City Hall
- Philip Ahrens, . Esquire 126' Daniel Ftreet Assistant Attorney. General Pertsmouth, NH. 03801 p
Augusta,.-ME D 04333 Da'.s Bisbee; Esquire
'Mr.' John B.~ Tanzer Assistant Attorney General.
Designated Representativefof. Office of the Attorney General the Town of Hampton' 206' State House Annex c 5 Morningside Drive' Concord, NH ' 03301 ~ Hampton NH 03842'
, Anne- Verge, Chairperson >
Robertal C. Pevear- , Boa rd of- Selec tmen Designated Reprdsentative.of Town Hall
-40 y the .TownD of ::Hampt'on Falls: South Hampton, NH 03827
. Drinkwater Road -
'Hampton, Falls, NH; 03844; PatrickI J. McKeon Selectmen's Office Mrs. Sandra Cavutis 10 Central Road L _ Designated Representative of. . Rye, NH -03870 theLTown of .Kensington-
~
.RFD l ' Carole F. Kagan, Esquire :
East Kingston, NH 03827 Atomic Safety.and Licensing Board Panel-U.S.- Nuclear Regulatory Commission
;Jo_ Ann' Shotwell, Esquire Washington, DC 20555 Assistant Attorney Generc11 '
Envi ronmental Protec tion . Bureau Mr. Angi Machiros
. Department ; of L the Attorney' Gene ral Chairman of the Board of Selectmen One. Ashburton Place, 19th Floor. Town of Newbury
- Bo ston , MA - 02108 Newbury, MA 01950 Senator Cordon J. Humphrey Town Manager's Office lu .S . " Sena t e Town Hall - Friend Street Washington, DC - 20510 Amesbury, MA 01913 (ATTN: - Tom Burack)
Senator Gordon J. Humphrey
- DiansLP.-Randall 1 Pillsbury Street
- .70 Collins Street Concord, NH 03301
. Seabrook, - NH = 03874 ' (ATTN: Herb Boynton)
h M Desee k $ dNa' $
, SB.1 & 2- Amzndment 56
< #E FSAR' November.1985 TABLE 3.2-1 (Sheet 6 of 6) ( ( *
~
' NOTES
- 1. These items not ' required 'as mechanical supports for CRDM housings ,- but
!are' required to ensure functioning of the control rods.
- 2. - Any reactor vessel internal, the single failure of which could cause release of a~ mechanical _ piece having potential for direct damage (as to the: vessel cladding) or. flow blockage, shall_be classified to a minimum of Safety Class 2 (see' Subsection 3.2.2.1 for definition), seismic (Category I.
-3. Failure-could cause_a loss-of-coolant accident,' but'less than a Condition III loss-of-coolant.
- 4. Ai1 seismic Category I structures are founded either on sound bedrock or:on' engineered backfill extending to sound bedrock. The type of l engineered backfill used beneath the foundations of all seismic 5,
. Category I structures was fill concrete, excep for safety-related
. electrical' duct banks, electrical manholes and~ service water-pipes which were founded.on offsite borrow or tunnel cuttings, as shown in Table 2.5-19. .
- 75. The conduit and cable tray raceway systems including their supports,.
when used to carry safety-related' circuit, cables and other raceway installations _whose failure during a seismic event could damage other safety'related systems or components are seismically analyzed as assemblies.. The items'that make up the supports-and cable trays are treated-a~s_no-safety related structural members, but are' purchased as a component with specific performance requirements. The manufacturer
.provides substantiating' test data and calculations, as well as a certificate of ' compliance . to his manufacturing standards. The supports N are assembled, installed and inspected in accordance with the applicable criteria of'10 CFR 50 Appendix B. The cable trays are designed, installed and inspected in accordance with Regulatory Position C.2 and-C.4'of Regulatory Guide 1.29, Revision 3.
a<d/e Ms =
. Qualification ~oftheconduitandcabletrayracewaysfortheClassJE safety related circuits have been confirmed by analysis 4 and bo d ot Nt$('>f ob eebe=&at4ena. verify the adequacy of the system based on the properties of the raceways (including tray where applicable) and ' support 1 components..
6.- -Components that are part of the dies.cl_ package but not essential to the operation ~i.e. electric motors for auxiliary coolant pump and auxiliary '
. lube oil pump etc., are not included in this category.
- 7. 'See.FSAR Subsection 8.3.1.1.a4 for exception pertaining to the
. protection _of the 13.8 kV containment electrical penetrations. )
z . . . . , . f:.;;.e.; 2 '
+ ~
p; h % tt 4 )
- sgal-Mil
&~
, ~ t c :5..
' s. .M , ,.
JSBil'& 2. Amendment 54; ~l j
,[ '
j FSAR: Februa ry .1985 ' l r; , -
)
^g
~ ^
W S..is' ratio corresponds l to-~a : period . interval' varying - from 0.0006 seconds at a . ~
.j 2 j period of ,0,031 seconds. to a' period Jintervalf of 0.01. seconds at a- period of ;
1 0.50. seconds.' q ,
-f 3.'7(B).1.3 Critical ~Demping Values 5 W* ; he;perce'ntages Lof critical;fviscous damping- used .for. the seismic analysis' of -
DCategorya I structures, systems, and . components are based ,on ' recommendations
- presented ;in"Regulatiory Guide l .61. : . Dese percentages, which account . for
- l' :; stress levi 1Jas :well 'ashtype of construction.or fabrication,. are summarized- i
' ' in Tabien 3.7(B)- 1.u
+
-:For f seismic; piping analysis, ' an . alternative to Regulatory Guide ;1'.61 may be -
1 used.1 J 3ese t values are ishown ' graphically in ' Figure 3.7(B)-39.- 9->2 hista TM.7(,BM.31
~
2 3.7(B).1.4 Su'pporting Medial for' Category I Structure s ( Allsseismic;Catego'ry I: structures .are founded ' on sound.. bedrock or on engineered . tbackfill. extending' to; sound bedrock. ~ Engineered backfill was also placed
~
~ -
1sround:a11Eseismic. Category I Estructures.- ~
^
une ;bedrockiatj the sitePis = uniformf1 competent,' and :no'nfragmented. ~ Engineering-
- propertiesEof;the1 bedrock measured in both the field and the laboratory are 5 pre sented Lin' Subsection ;2.5.4.'2.a. - >
m_ Ane engineered backfill consists tof either fil1~ concrete, aback fill' concrete,
- ~ "
P 7 Affaite 4orrowj2 tunnel cuttingsi or' sand-cement.: -Properties of the engineerdd -5
~
-backfill materials:are Edescribed in Subsection 2.5'.4.5. ne . type of engineered :
Sj (backfill:used beneathi all seismic.'Categoryll structures .was fill concrete, -
' ?@ /cuceptl for safety 4ela'ted -electrical duct b'anks, :five' electrical manholes, f cnd :the. servicel water pipes,. which~ were founded on of fsit'e. borrow or tunnel- i *
- cuttings,-- as shown in Table;2.5-19.
~
' 4 s:> -. . , .
- Identificatio'n of Lthe safety-related electrical manholes founded on offsite' L borrow l orttunnel cuttings, the; depths 'of of fsite borrow or z tunnel cuttings
~
E cver itheibedrock_ under -these' particular. manholes, - the widths of thei_r struc- -g.
' tural: foundations and the total! structural height- are sununarized below:
; Depth s' o f f -Widths'of- Total-
- { Manhole: , Soil over- '
- St ruc tura l Structural Supporting- t INumbers Bedrocki ( f t) Foundations (ft) - Height ~(ft) Material n 3 .
W13/W14' i6-12 -
.18 x 18 9 Offs'ite Borrow "yjW15/W16: 6-12, 18'x 18\l 9 Offsite Borrow'.
E W19/20i e ' 15 :- '23 x 23 . 12s hnnel Cuttings LW29/W30 m 14- 19 x'22h 15 offsite Borrow _W33/W34; - 18' 18 x'18%- 12 ' Of fsite Borrow '
.M
)
3.7(B)-2
,,r-w 3N w',-.. =.mw. . - - : -- .
7:7 , s M4 k bN*hN r s SB 1 & 2. Amendment 56 FSAR November 1965
. t ..
TABLE 3.7(B)-23 CRITICAL DAMPING VALUES i Itert y. te eipment ' Damping _ Percent or comp,nent Critical e OBE 'SSE PipingSys'tems> ~1 2
- Valves, Compact Pumps, Compressors, 11 2
?! _ Diesel Generators,' Pipe Mounted'- Instrumentation . Su lleat Exchangers, Tanks & Vessels, 2 3 Control Cabinets', Deep.Well Pumps,' Fans,. Electrical Switchgear,
-Filters,: Dampers,' Motors Electrical ~ Conduits _with 4 7 Bolted Connections
; -- - Electrical. Conduit with Welded -- 2 4
- ' Connections; Equipment' Supported by. '8 8 Seismic Dampers dl Tfs Eefer b4Y ek*
NOTE: _ Higher damping values may be used.provided that adequate justifica-tion'is available. W L l
= - * --
p g_
% ~
&L 0 S
W 7 SB 1 & 2 Amendment 56 FSAR-November 1985
;7
~'
3.10(B) SEISMIC QUALIFICATION'OF CATECORY I INSTRUMENTATION AND ELECTRICAL EQUIPMENT
-This section discuss'es the seismic qualification criteria, methods and
' procedures employed by the A-E for the qualification of seismic Category I
' instrumentation and electrical ~ equipment within his scope of: responsibility.
.It also covers the methods of' analysis or teating of the supports for the'-
electrica1' equipment.and instrumentation. Seismic Category I instrumentation and electrical equipment are. listed-in Tables 3.2-1-and 3.2-2. The corre -
-sponding discussion for.the electrical equipment, instrumentation and supports l
. provided by the NSSS supplier is found in Section '3.10(N).
3.10(B).1 Seismic Qualification Criteria The criteria employed for seismic' qualification of seismic Category I ' ? (Class 1E). electrical equipment and instrumentation, other than NSSS-related equipment,; follow the guidelines recommended in IEEE Std. 344-1975 and Regulatory Guide 1.100. The. seismic Category I instrumentation and electrical equipment are. designed to' withstand,fwithout loss'of. function or structural integrity, the combined effects, of all . normal operating loads and the seismic loads of the Safe Shutdown Earthquake..(SSE) or the Operating Basis Earthquake (OBE), as defined in Subsection 3.7(B).1._ ' " '(,- The seismic' Category I instrumentation and electrical equipment are seismically qualified.by using either analytical methods or resting, or by a combination of both, as follows:
+
orIe5ba
-a.'
The equipment which does not undergo a change of state.are qualified by analysis o establish structural adequacy. This includes cable t tray systems, cable conduit' systems and bus duct systems. When analytical methods are used~to qualify the' seismic Category'I equipment or_ component, stresses resulting from the'seis*.ic acceleration effects are combined with stresses due to normal operating loads. Both horizontal and vertical seismic loads are assumed to occur-simultaneously in the most unfavorable' combinations, i
.and the-two horizontal and'one vertical seismic load-induced stress components are combined by the' square-root-of-the-sum-of-the' squares method. The' stress levels due to the combined normal design loads
'and seismic' loads are maintained within the stress levels set forth' in appro~priate design standards and codes. If there are no code requirements .in the. design of the equipment or portions thereof,
- then the. stress level under the above combined loading, including the normal design loads plus SSE seismic load condition, is limited to'90-percent of the minimum yield strength'for the material. In addition, the equipment or component design is reviewed to assure i
that any resulting deflections or distortions do not prevent the l proper functioning of the equipment, nor endanger adjacent equipment or components.
~
3.10(B)-1 e~ ;
_ QMgeogggk 1 M*M
^L SB I & 2. Amendment 56 FSAR November 1985
' The ' criteria for selecting a static load analysis or dynamic modal analysis are decided by the complexity of the equipment, as delineated l in'IEEE Std. 344-1975.
-> SNSERT 74o(s').1 b._ 'The equipment or components which must be capable of undergoing a change of state are qualified by a combination of seismic and-functional. testing both during and after an earthquake of magnitude up to andcincluding the_SSE. The equipment or components are tested for. ability to retain' structural integrity, and no malfunction is
. permitted where such a malfun'ction could jeopardize the capability to: safely shut down the reactor and/or mitigate.offsite exposures.
When; testing-is used to qualify seismic Category I equipment or components, testing is performed in accordance with IEEE Std. 344-1975.
- c. ' Seismic Category I equipment supports, including cabinets, panels, consoles and instrumentation racks are qualified by either analysis
-or testing using appropriate horizontal and. vertical floor response
~
. spectra lat the building and elevation at which they are installed.
When analys'is'is used to qualify the' equipment-supports, the stress
. criteria are in accordance.with AISC Manual of Steel Construction.
- d.
LSeismic qualification. tests are conducted for battery prototypes
.with. cables-(or equivalent batteries with cables) in accordance '
.with the requirements of IEEE 323-1974 and IEEE 344-1975. The
. battery racks are qualified by appropriate seismic analyses which include the battery masses. The Class IE transformers are seismically -
}
-qualified by: test usingfan' appropriate. test-apparatus.which" includes 47 the supporting structures or cabinets and all relevant appurtenances including cooling accessories. -This effort is included in the
~
Class lE Unit Substation Qualification as noted in Table 3.10(B)-1. M 13.10(B).2 Methods and Procedures-for Qualifying Instrumentation and
-Electrical Equipment
~
1* Seismic Category-I instrumentation and electrical equipment (other than NSSS) ;
;were qualified either by analysis,-by testing, or by a combination of testing
-ind analysis as. indicated in Table 3.10(B)-1, to confirm their functional icperability during and after.an earthquake up to and including the SSE.
'All specifications for seismic' Category I instrumentation and electrical cquipment included the seismic design criteria discussed in Subsection 3.10(B).1 as a,part of the design condition. Tests or analyses are per-formed in accordance with the criteria and the intent of IEEE Std. 344-1975
'cnd Regulatory Cuide 1.100. Amplified floor response spectra applicable to
- the particular' equipment locations were included as a part of the specification.
The. seismic intensities indicated in these spectra were,used by the manu-facturer:for seismic qualification of the equipment and capability documen-tation.
' Certified test report and/or analytical calculations were obtained from each <
vendor to confirm that the purchased seismic Category I instrumentation and 3.10(B)-2
~
~
bd4 dbh i f' s-SB 1 & 2 Amendment 46 FSAR August 1982 electrical. equipment.will perform its function when subjected to the 1
- stipulatedi seismic loading conditions 'of the SSE. Al** test reports and-calculations were certified by a registered professional engineer, skilled in the applicable specialty, and by a responsible officer of the -
manufacturer or vendor. Equipment anchor loadings and details, such as size and spacing of anchor bolts lor welds, were obtained from the equipment manufacturers for use in
-designing foundae. ions or supporting floors for compatibility with the seismic anchor loading ~of the-equipment.
3.10(B).3 Methods and Procedures of Analysis or Testing of Supports of Electrical Equipment and Instrumentation 3.10(B).3.1 ElectricalEouipment and Instrument Supports The qualification of supports for main control boards, cabinets, panels and-
-instrument racks,.as well as supports for electrical equipment such as battery racks,Lwas accomplished using one of the methods ~ discussed in Subsection 3.10(B).1. The methods used in evaluating the supports were testing under simulated conditions and analytical approaches. Analytical
~
-methods were employed for the anchorage of the supports. Amplified floor
. response ^ spectra for the locations where the equipment is mounted are
( provided to the equipment supplier who is responsible for qualifying the equipment.. Supports for instruments and electric equip =ent are attached by bolting or welding to anchor plates fabricated of ASTM A36 steel, either embedded in the concrete with~ stud anchors or surface mounted to the concrete using bolt anchors. In either case, they were designed to prevent uplift or' overturning effects due to seiemic forces. 3.10(B).3.2 Cable Tray Supports orif6ded Raceway systems when used to carry safety-related circuit cables, are qm. designed to withstand the seismic forces which would be experienced during
-an SSE due to the weight of the cables, raceways and supports. Cable tray b
' load-deflection curves were used to formulate a simplified analytical model of the' tray which was then coupled to the analytical model of the supports. )(- /N5aT The response spectra method was used to analyze the overall analytical model g g ,2, and to design the support structures, while complying with the tray support system functional requirement.
The. cable tray ' support system was analyzed for dead load combined with the OBE loads, with the stress criteria based on the allowable stresses of the AISC Specification on Structural Steel for Buildings and the engineering information for strut members published by Unistrut, Powerstrut or
-Superstrut. For dead loads combined with SSE loads, the stresses are limited to 90 percent of ' yield stress for the material involved. For the seismic loads, the actual natural frequency response of each support system was calculated and the appropriate seismic acceleration factor was selected f from the amplified floor response spectra (see Section 3.7).
The cable tray supports consist of structural shapes and strut members. 3.10(B)-3 m
hgkyggegf 1 ' 6h - PROPOSED'FSAR CHANGES t.:
~'
Insert for 3.7(B) .1.3 For the Cable Raceway System,.an alternative to Regulatory Guide 1.61 may.be used. Critical damping levels' may be a maximum of 20 percent for input acceleration IcVels of .35g and greater for OBE and SSE conditions. In cases where input accelerations are between .lg and
.35g. the critical damping values maybe interpolated between 7 persent and 20 percent respectively.
. Insert for 3.10(B).1 a
[~. - When testing-methods are used to qualify cable tray systems, the. testing performance will meet the intent of- IEEE-Std. 344-1975. Insert for '3.10(B) .3.2
. Load . deflection' parameters may be established by testing to.
-formulate the analytical models of the cable tray supports b.
..~
/
l r . -- - :__ 3
.- b -
-{. [~i . . -
?p ,
b kQ __ x %m w- - . L a._ TATTACHNENT'3 4 - _ :Responsekto'openitemsasiaresultoftheDecember3meetingwithNRCstaff
,y and New Hampshire Yankee'.,
, f 1. c .-Are:Seabrook configurations covered by Bechtel Owner's Group-Program on %R (Higher Dampingt'
~
~' ' = ' '.N' ,
'/les;[As's separate effort,'Bechtel was contractedJin February 1995 to g' '
y l perform a comparison study of Seabrook-raceways.with. 3 data base tested
. raceways. 'This-study. concluded that Seabrook tray designs'are bounded by 1 , ; the Bechtel data base and the'7% to 20%. damping values are applicable. A
. presentation was made'to;NRC.in May 1985, and' tentative approval-lobtained. iSee: Paragraph:4.1.4'of Attachment 1 and Reference (b) to the cover letter for-more detail.'
t
. ! 2.5 -Is the-. structural'a$ceptance criteria to be utilized in the revised
, (qualification program different from the original?'
' Structural acceptance crite*-la -is. listed in Paragraph 3.3 of ~
LAttachment-1. For primary members' (struts and Hilti anchor bolts), the present; project criteriaLis' maintained. For connections, acceptance criteria'is derived from'results'of dynamic and static tests, including
,our: plant-specific hardware tests, and the Bechtel generic tests. A l detailed discussionjof connection capacity criteria'is contained in.
zy Paragraphs 4;1.and4j2.of1 Attachment 1. 3.. ; Will your program utilize extrapolations of test results to tray -
'(, f Jarrangementslmuch;iarger and carrying more mass than the tested nb -configurationst~ ' ~ ~ r
. . py ,
.Qu'alificationidiepetlygby one of the four test configurations will.only be applied to plant configurations which fit in the' envelope'of tested:
; geometry and mass..~(Note: Test Response Spectra botands all effected tray, support' locations.) For example,fa' trapeze.configuraf-lon
~
-approximately 30.: feet'in length with five tray layers would be qualified s Ldirectly byd'est: A. 'A trapeze configuration of 50 feet ~1n: length 1
comprisedLof'eight tray layers does not fit directly'Lin the test envelope. , - > These larger geometric sizes will be qualified by calculational enalysis , as described in Section-4.0 of Attachment 1.
- 4. .Does your overall qualification program rely on bounding calculatione of a sample of the~as-constructed plant configurations? How do you verify that all-support sections are qualified?
f our, program is not_ based on sampling. The.as-constructed details of each
-support will be compiled'and compared in detail to the bounding. !
; mathematical models.shown in Figure 4-19 of Attachment 1. Each support l
. arrangement which is not qualified by bounding evaluations will be j subjected to a specific Analysis. ,
i r 5
-l 4
I 4 s
, . . h m - . , ,. ,
~ n
.t -
.; n
. =
' ' ^^' ~ ^ ^ ^ ^ ~ ^ ~ ~ ^
'Yf "Y s.
MQ.. g 1
?[ C&
.$UiI'l
)Q^y[ ,
q m .y . zDetAlls ofjthe as-constructed program were reviewed by Region I personnel
~ ^n .in. November 1985.with no open items resulting.
- i, ,y .-
YEachfcableitray' support _will.be subjected to an-as-constructed. evaluation
._ "and : documentation will be provided to justify the qualification.
'The'severitylof the test input (bounding ARS, fragility test to 1.3 x
> I:SSE(maximum 1 cable _ loading)andthe'substantialmarginbetweentest
*g
' " ? response spectra and typical floor response spectra provides a high level
, ~ oftconfidence that-all. tray: configurations will be qualified in their
- present state, by either direct ~ test. comparison or calculations, c 5.' :Will'Seabrook; delete or remove any of the installed bracing as a result
~
~of this program?.
!No;.ittis our intent to qualify the tray support configurations'as 7
presently constructed. 6' . fDoes this~ qualification program' utilize methods and r,riteria similar to
., comparable NTOL facilities?
-2The critaria is essentially. identical to that utilized in our existing Jcable tray design methods,which a're very similar to other NTOL facilities., Specific changes to our existing program are as follows:
'a. Use of. dynamic' tests to directly qualify a percentage of tray l supports. . Dynamic test. sequence satisfies the criteria in IEEE-344,. ,
- an' accepted industry standard for. seismic qualificatica of equipment. !
, b .~ Utilization of connection stiffness values.in analytical models.
?+rc ~ # ~
.This is in~conformance with past methodologies utilized by Bec! b l n Corporation'at other NTOL facilities.
/ c. Utilization of extensive te.st data to establish connection
/ ' acceptance' limits.
, q GP l-i g 7 l
A b' ~
~
- _ _ _ . _ - . _ _ _ . _ . . _ . - . _ . _ _ _,}}