Regulatory Guide 1.103
| ML13350A289 | |
| Person / Time | |
|---|---|
| Issue date: | 11/30/1975 |
| From: | NRC/OSD |
| To: | |
| References | |
| RG-1.103 | |
| Download: ML13350A289 (4) | |
U.S. NUCLEAR REGULATO
COMMISSION.
REGULkizORY
GUIDEOFFICE OF STANDARDS
DEVELOPMENT
REGULATORY
GUIDE 1.103POST-TENSIONED
PRESTRESSING
SYSTEMSFOR CONCRETE
REACTOR VESSELS AND CONTAINMENTS
November
1975
A. INTRODUCTION
(;General Design C(riteriun I. "Quality Standards andRecords"
of Appendix A. "'General Design Criteria forNuclear I(oiver PlanIs."
to 10 C(FR Part 50. *'Licensing if Prodlucion.
and Utilization Facilities.'-
,equires.
inpart. that structures.
systems.
and components im-lporlani to safety be designed.
fabricated, and erected to(tllality standards commensurate with the importance ofIhe saflcy luncliotins to be performed.
This guide identi-ties Ithe post-tensioned pcstressing systems Iltat hiavebeen reviewed and ai.rovcd by the NRC staff for use inconcrete reactor vessels and containmnents and alsodescribes qualifications acceptable to the NRC slafr fornew post-tcnsioned prestressing systems.
B. DISCUSSION
A oims-tensioned prestressing system is composed ofa'prestressing tendon combined with a method of sira.sing and anchoring the tendon to thie hatrdened coz.crete.Th.e word "symeste is commonly associated ith the. dif-"fercn i proprietary post-tensioned prestrcssing.systenl oilIhe market and is understood to include .the. type oftendon, anchorage device, and stressing equlipment associated with a given systemi.-.
It is not practical ito discussthe details or all of themany post-tensioned:.irestressilng sysiems available in theUnited States. Nlore)ver.'"inw pidit-tensioned prestressing systems are being: devclopod, and existing ones are beingmodified.
F-6r "te nsreas. the descriptions in thisguide are to -systnis listed in Table A. all ofwhich havbeel used or proposed for use.Some examples of use are presented in order toidentify iiore specifically thie system being discussed andto provide a rel'erctice io some plants for %,'hich tilesysvetns in Table A have been proposed o, approved.
Theex:amples cited are not intended to *indicote anytestriction or prel'evence in size of the tendot for a givensystem. Nor is this -uide intended
'to discourage thedevelopmtent of refinements of curr.ent systems or thedevelopment of new prestressing systems or concep)ts.
"hte quatliflcat ions dhat a post-tensioied piestnessitig s'.stem should meet in order td ibe acceptable to tieNRC st-a Tare iden~ified in tlicaiegulatowv positioti.
Rockanchorage systems are..not covered by this guide.Types of SystemsSTlhie type tof tendon selected usually diclates thechoice of stressing eqluipment and also affects the choice,of end .atchorages.
Basically.
post-tensioued prestressing systenis can beseparated into Ihree general categories by Ihe types ohterndon in use: wire, strand. and bar systems.
lEtndanchorages for these tendons are based ott either wedgeor direct-bearing p.inciples:
sometimes a combination ofihe two is used. A description is presented below otpost-tensioned prestressing systems in ternis or types tittendons and end anchorages.
Wire Systems.
Wire systents employ a tumber otparallel wires grouped to form a tetndon.
Wiresmanufactured in the United States conforni to ASTMtSpecification A-421. "Uncoated Stress.Relieved Wire forFPrestressed Concrete."
This specification provides forwires of two types (BA or WA). depending on w\hetitetltey are to be used with buttons or wedge.type anchorages.
USNRC REGULATORY
GUIDES C,,,nierr-ns should be sent to the Secretarv of the U S NuclearAreqUlallor Conui'I*,Ison.
Wasin~l~gtoni.
D C M56 Alttention Docketing andoRegulatory ire to and otike to Ihe Iyith. Seulit SeCtion .Amethods acceptatle"
o thtf NRC ftill tot rmpim enmrting specific par the rf SeConinti.,5on I reguajutions.
10 delineatei techniques used by th" tiltl an ttvalu lb. qutirmtesate issued in Ihar following ton brand divisionh Chirq it spi'ct c rutalems, or vustl.fle~d
.Atc~dnlel.
or to Iriovad.
g lsani.n I,, itplicants ARguldiriao Guidesi at.e not subslitults fot regulations.
and I Powser Reactors
6 Productswith them inot retjtlleii Miridb dint SnIu Illto- fIoent front lhose set (,,ii itt 2 flese'rch and Yost Reacit% 7 Transtproation th: wit: he it th v'y provide a t ht,,% fit tie fandings requisite to 3
8a Occuptilonl Heoalththe islsum Illo itlt!tte
.ii1 rt tir the ICunmnmisiOn
4 Ern-tioninientl and Siting 9 Antitrust ReirewC(rrrriietlsfl1 trait+ Stiajleslilis
1,14111 IiiLVitullill11t5 ii ttlhlse ajiantaits itlt. rielt l later
i. rts aild PIrItM
tO Geneta lt ii tt11 , .J q wil" it t1i. l ,l a iI t aIaiiiI .t-1lu ,ict..ill.....l..late
- oin,MGMlls rid,1 tIa iiltte,'.t
-ew it..I-li.iiiiiii t..(uial r --ý c ...l..irvit.
.i1rntt...1it.
ian C(i:;aie of tulAtished guides rtady ble olbtainld lIv written request aidacating theINis iju li1.. ii tem .itm (l artaila ,it Iii t 1a 1111m1la
.Ilrer its O , as, i i.'. .,il tie iPa divisions desired to the U tS Nucltear Regultatuor Commission.
W a~shtng lor .0 CtImulai ly usef ll iii t h li llil lii ' niri. .t l .t ..i ..i.. y IV .,..a....
IOt2 5, Allen tion D lte .lol. Office of ,Slandaidi Develtopm ent The BBRV system, developed in Switzerland byBirkenmaier.
Brandestini.
Ros. and Vogt. is a wiresystem used in both concrete reactor vessels andcontainments built in the United States. The mainfeature of this svstenz is the. use of cold.lormed buttonheads for direct bearing at each end of the wire.Tie prestressed concrete reactor vcssel (PCRV) of theFort St. Vrain station in Colorado employs the B3BRVsystem with 169-wire tendons developing approximately
2000 kips capacity each. A number of 2-ontainnienls utilizing the BBRV system with 90, 163. 16). 170. and186 wires per tendon have been built in the UnitedSlates. The wire diameter is 1/4 inch (6.35 imm) in allcases except fur the 1 63-wire tendon, which uses 7-mm(0.28 inch) wire.Strand Systems.
Strand systems employ a number of"'strainds"
that are bundled into a tendon. A strand ismade tip tof a number of factory-twisted wires.Stress-relieved strand is made in two forms. The first isthe seven-wire strand. which conforms to ASTMSpecification A-416. *'Uncoated Seven-Wire Stress.Relieved Strand for Prestressed Concrete.-
The secondforni consists of larger strands Iltat are made of largerindividu al wires anid may consist of more thian sevenwkires per strand. vhe larger strands are not covered hyASTM spicifications and have not been used for theconstruction of nuclear power plants in lhe UnitedSlates.Strand systems have been introduced in the construc- tion of nuclear power plants by Strand-Wrap, N'SL.(Vorspann System Losinger).
Stressteel.
Freyssinet.
andSEEE (Societe d'Ettides et diEqtiipments d'Enterprises).
The last two systems were considered but have not yetbeen used in the United States in nuclear power plants.Both the Freyssinet and SEEE systems have been used inEurope on concrete reactor vessels.The Strand-Wrap system has been reviewed andapproved only for applying hoop prestressing
1o soinePCRVs in the Ltnited States. The basic principles ofapplying ltoop prestressing to the PCRV by theSirand-Wrap system are the same as those forconventional prestressed concrete tanks and circularliquid containers ithat have been built using wire-winding machines.
Steel-lined circumferential precast concretechannels are anchored to the outer cylindrical surface ofthe vessel by reinforcing bars extending radially inwardfrom the precast channels.
The strand is anchored at oneend by means of a tapered wedge grip in the rib betweenadjacent channels and then wound around the vessel atihe design tension for a number of turns and anchored inthe next adjacent rib. Each band of circumferential prestressing consists of multiple layers of strand woundonto these channels.
Each layer consists of onecontittuottis length of strand. A maximum hoopprestressing force of about 6600 kips per linear foot ofvessel height is being used in the design of the PCRVhead region of the Dehmarva Summit Power Station.The VSL strand system was.developed in Switzerland.
This system employs a wedge anchorage for strands.Each strand is drawn through the openings of both thebearing plate and the anchor head and is held by atwo-piece split cone wedged tightly against the innersurface of the anchor head. As an example.
theconttainmnent of the Rancho Seco Nuclear Generating Station*
in California employs the VSL system withtendons consisting of 55 strands.
each tendon developing
2250 kips capacity.
The Stressicel S/Il multistrand systemi was developed in the United States during 1967-1968 by Stressicel Corporationi in cooperation with llovwlett MachineWorks. The system is characterized by a three-piece slotted wedge cone that grips three strands in its serratedteeth, with a number of wedges in a single anchor platemaking up a ittllistrand lendon of the desired size.As at, example.
the conlainment of the Three MileIsland Nuclear Station Unit No. 2 in Pennsylvania employs the St resstecl S/Il multistrand system coisisLing of tendons with 54 1/2-inch.
Grade 270K. 7-wire strandsper tendon, each tendon developing
2230 kips capacity.
The Freyssinet systemn was naimted after (ie Frenchengineer Eugene Freyssinet.
who itivented the anchorage device in I939. The original anchorage device was for awire system only, This is a comn monly used commercial system. The anchorage consists of a male conical plugand a female conical recess. The plug. with the wiresspaced evenly around ils perimeter, anchors tile wire bywedge action.As a result of market requiremenmts and subsequent developments.
the Freyssinet system now also hasavailable anchorages for strand tendons and other shapesof anchorage devices different fron the original one. Theswame wedge principle for the tendon isretained, however.
Concrete reactor vessels have becnbuilt in Europe using the Freyssinet strand system with amaximum tendon capacity of abouw 2000 kips.The SlEHk system was developed in France by Societed'Etudes Ce d'Equipnments d'Enterprises.
The systemfeatures threaded anchorage fittings extruded onto theends of a group of strands.
An anchoring nut is thenthreaded onto the anchorage fitting and turned tightlyagainst (lte bearing plate. A tendon is composed of oneor several such anchorage fittings on a common bearingplate.Bar Systems.
Bat systems employ a number ofhigh-tensile-strength steel bars that are bundled into a*The Irey-yinet.
SI-l-, and VSL systemsl were formallyprt.m-niled is allternatives to Ile previomstiy approved IItIRVsystem. Thme V'SL syteim was chosen by Mhe applicant.
Consequently.
the Freyssinel and SIE systems were notrnvicwed by the NRC starf w ith regard to their acceptability foruse in nutclear power plant Containments.
1.103-2 Mtendon. "l Ie bars are mnade front an alloy steelconformiug to ASTM Specifications A-322 and A-29.A-322 is a general specificalion that covers only thechemical composition of many grade dcsignatioi.,
ofalloy steel bars. and A-29 is a specification for generlrequirements for hot-rolled and cold-finislted cat bun andalloy sled bars. No ASTM specinication covers theininimuni mechanical and physical requtirementlls for theprestrcssing bars after processing.
as in the case (if' wires(A-42I ajnd strands (A-416) and it is for this reason thata speciticati
)i* was written by tre Prestressed ConcreteInstitute.
Bars are cold-stretched and also stress-relieved by heattreatmenu Ito produce the prescribed mechanical properlies.
Bolih defornied bars and smooth bars withthreaded ends are available.
hut only sinooth bars havebeen used for unclear plower plant conStructioll in tiheUnited Slates.The Stressicel Corporation in the United Statesemploys a bar system. The bars are stressed by mneans ofan hydraulic jack that consists of a coupler and pullingbar. The normal commercial tech tiique for anchoring uses anchor nuits. During stressing.
t[le anchor nuts arecontinuously screwed down on washers and bearingplates. and the prestressing force is then transferred totile anchorage assembly by releasing the force in tihejack. Wedge atn' grip-nut anchorages are also available toanchor the bar; they possess tile advantage of being ableto grip the bar at any point along its length.The containment structure of H1.B. Robinson UnitNo. 2 in ilartsville.
Soutlh Carolina.
employs lieStresstecl bar system anchored with Howlett Grip Nuts.The tendon. comuposed of six I -3/8-inch-diatnuter Stressleel bars,. develops a cap',:ity of 1428 Kips.Grouted and Ungrouted TendonsAll of the concrete reactor vessels and containments designed and built in tie United Slates use ungroited tendons except for H.B. Robinson Unit 2 (bar tendons),
Three Mile Island Unit 2 (strand tendons),
and ForkedRiver (strand tendons),
all of which were designed forgrouted tendons.
On none of these, however.
has desigincredit been Oven for any bond of the grouted tendons.Whether grouted or ungrouted tendons are used, ameans of determining ile functional capability oif [liestructure during its lifetime should be available.
Thisresults in a need for reliable quality assurance procedures for t[le tendon installations and a need for a reliablestructural inservice inspection program.
To date, this has""(;uide Specification for Post-Tunsioning Materials,"
PCI Post-Tensioning Manual. Prestressed Concrete institute,
1972.been easier 1o acco inplish tltough lite use olftngrouted tendolns.
C. REGULATORY
POSITIONThis regilatory
!!tuide the generic qualificatiors otf systenis lised in colnclete reactor vessels and conlainrlieits.
with Ilo) atlerlmi toextenid its scope to design aspecis.
The accepiahility olany posil-ellsiolled prestre.Nsirig syslelm ill conjunction with a specific structute design woitld lhave to bieevaluated on a case-by-case basis. Any proposed systemsubmitted for NRC approval should consider tilefollowing:
1. Post-tensiuned prestressitig systeirs that havebeell approved in previous nuclear powcr plailt licenseapplications are regarded as accepted systems.
SeeTable A for idcntification.
When tie clain is nade by ailapplicant that tile prestressing sysienr proposed is ailaccepted systei.,
sufficient int' [rination shouttld be pro-vided with each iipplication to demonstrrtc that tilesystem proposed is the samne as tile that wasapprolJd iii !.ý'\vious muclear powel plant license ;ipplicaiions. Pri:,-r approval of any system does Inol relieve tileapplicanm of the responsibility for demonstrating that itssvslenli leets all tle requirementIs of thle forConcrete Reactor Vessels and Containmenls.41
2. Changes in prestressiig element materials or inaichorage items of previously accepted systems thatmay require replieatig the., system peritrtnance tests areidentified in Subsections
('11 and CC, Article 2406 of theCode for Concrete Reactor Vessels and Containmntetils.
3. Any new post-tensioned prestressing sysreirishould meet the requiremenls set fo7rth in tile Code to,Concrete Reactor Vessels and Containments.
4. The use of any prestressing system should permit the applicatio of ail iriservice inspection program that will verify the continued functional capability of tile structure.
Implemenlation of this program should not degrade the quality aidreliability of the post-tensiorled prestressing system.Regu.latory Guides 1.35. "'tisetvice Inspection ill UnIli.grouted Tendons iin Prestressed Concrete Containumen Strulctures.'
and I.90. "Inservice Inspection Pre-stressed Concrete Containnient Structures with (GroutedTendons."
should be consulted for recommiendations concerning the use of ungrouted and grouted concretecontlainrents, respectively.
"ASME Boiler and t'ressure Vessel ('ode. Section It
t. Division
2(tile latest version, plus addenda, as endorsed by t(ie NuclearRegutatory Commission).
This Code is currently under reviewf'or endorsement by the NRC staff.1.103-3 D. IMIVPLEMENTATION
porilons of't ile Ct ininlission'~s reglIluc ions. tile Ilethoddec~ribed hecrein %%ill be used inl tile evaluationt ofsuhbmittals for const ruction permit applicatiouns do cketedTheI. pur Ipos OfL 1 r iS isNC I io is ito provide ii tort u (on after J1 Liie 30, 1 976).(o alpp ic a mu s a utd li elscees regard in g tie staff's phlans forusing~l this regullatory
-titl
e. I all applicant
%%ishles wo use this repuiit:Iory lideill.'hit lt lhoste cCases ill which theile aplicalt proposesaft;dernaltive metho)d fotr
%%ith spec.ified developing submnittals tku applicat:ions docketed til orbel'ore JuIte 30. 1976. the pertinemn portlnuls oi tlieapplication
\Mi] lhe evailaied oin the basis ol" this puide.TABLE ASTATUS OF SYSTEMS AS OF MAY 119751Por I. iccnlsh~ii Revi'it'.xIRr i e',s , i~ c iv i; iahl itA'RCstaffuse(/In US. A'tich'ar
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RCGULATORY
COMMISSION
UNITED STATESNUCLEAR REGULATORY
COMMISSION
0. C. 20555OFFICIAL
BUSINESSPLNALTY FOR PRIVATE USE. S3001.103-4