Regulatory Guide 1.103

Post-Tensioned Prestressing Systems for Concrete Reactor Vessels and Containments.

ML13350A289
Person / Time
Issue date:	11/30/1975
From:	NRC/OSD
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RG-1.103
Download: ML13350A289 (4)

U.S. NUCLEAR REGULATO COMMISSION.

November 1975 REGULkizORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 1.103 POST-TENSIONED PRESTRESSING SYSTEMS

FOR CONCRETE REACTOR VESSELS AND CONTAINMENTS

A. INTRODUCTION

to provide a rel'erctice io some plants for %,'hich tile sysvetns in Table A have been proposed o, approved. The

(;General Design C(riteriun I. "Quality Standards and ex:amples cited are not intended to *indicote any Records" of Appendix A. "'General Design Criteria for testriction or prel'evence in size of the tendot for a given Nuclear I(oiver PlanIs." to 10 C(FR Part 50. *'Licensing system. Nor is this -uide intended 'to discourage the if Prodlucion. and Utilization Facilities.'- ,equires. in developmtent of refinements of curr.ent systems or the part. that structures. systems. and components im- development of new prestressing systems or concep)ts.

lporlani to safety be designed. fabricated, and erected to (tllality standards commensurate with the importance of "hte quatliflcat ions dhat a post-tensioied piestnessitig Ihe saflcy luncliotins to be performed. This guide identi- s'.stem should meet in order td ibe acceptable to tie ties Ithe post-tensioned pcstressing systems Iltat hiave NRC st-a Tare iden~ified in tlicaiegulatowv positioti. Rock been reviewed and ai.rovcd by the NRC staff for use in anchorage systems are..not covered by this guide.

concrete reactor vessels and containmnents and also describes qualifications acceptable to the NRC slafr for new post-tcnsioned prestressing system

B. DISCUSSION

STlhie type tof tendon selected usually diclates the choice of stressing eqluipment and also affects the choice A oims-tensioned prestressing system is composed ofa' ,of end .atchorages.

prestressing tendon combined with a method of sira.sing and anchoring the tendon to thie hatrdened coz.crete.Th.e Basically. post-tensioued prestressing systenis can be word "symeste is commonly associated ith the. dif-" separated into Ihree general categories by Ihe types oh fercni proprietary post-tensioned prestrcssing.systenl oil terndon in use: wire, strand. and bar systems. lEtnd Ihe market and is understood to include .the.type of anchorages for these tendons are based ott either wedge tendon, anchorage device, and stressing equlipment or direct-bearing p.inciples: sometimes a combination of associated with a given systemi.-. ihe two is used. A description is presented below ot post-tensioned prestressing systems in ternis or types tit It is not practical ito discussthe details or all of the tendons and end anchorages.

many post-tensioned:.irestressilng sysiems available in the United States. Nlore)ver.'"inw pidit-tensioned prestressing Wire Systems. Wire systents employ a tumber ot systems are being: devclopod, and existing ones are being parallel wires grouped to form a tetndon. Wires modified. F-6r "te nsreas. the descriptions in this manufactured in the United States conforni to ASTMt guide are Ii*u16 to -systnis listed in Table A. all of Specification A-421. "Uncoated Stress.Relieved Wire for which havbeel used or proposed for use. FPrestressed Concrete." This specification provides for wires of two types (BA or WA). depending on w\hetite Some examples of use are presented in order to tltey are to be used with buttons or wedge.type identify iiore specifically thie system being discussed and anchorages.

USNRC REGULATORY GUIDES C,,,nierr-ns should be sent to the Secretarv of the Commiss*,on. U S Nuclear AreqUlallor Conui'I*,Ison. Wasin~l~gtoni. D C M56 Alttention Docketing ando Regulatory Galde* ire i*,sued to desc*ibe and otike aviddh*le to Ihe Iyith. Seulit SeCtion .A

methods acceptatle" o thtf NRC ftill tot rmpim enmrtingspecific par the rf Se Coninti.,5on I reguajutions. 10 delineatei techniques used by th" tiltl an ttvalu lb. qutirmtesate issued in Iharfollowing ton brand divisionh Chirq itspi'ct c rutalems, or vustl.fle~d .Atc~dnlel. or to Iriovad. g lsani.nI,, itpli cants ARguldiriao Guidesi at.e not subslitults fot regulations. and Conipli*lhco I Powser Reactors 6 Products with them inot retjtlleii Miridb dint SnIu Illto- fIoent front lhose set (,,ii itt 2 flese'rch and Yost Reacit% 7 Transtproation th: gui*de* wit: he 'uptih*lt*te it th provide v'y a t fit tie ht,,% fandings requisite to 3 hueldsandMa*terl*1,Faciltes 8a Occuptilonl Heoalth the islsum Illo itlt!tte . ii1 rt tir ticrmnei*ihthe ICunmnmisiOn 4 Ern-tioninientland Siting 9 Antitrust Reirew C(rrrriietlsfl1 trait+Stiajleslilis 1,14111IiiLVitullill11t5 ii ttlhlse ajiantaits itlt. rielt lateri.rts l aild PIrItMPiolec*irn tO Genet a lt ii , . Jtt11 q wil"itt1i. l ,l a iI t aIaiiiI . t-1lu ,ict..ill.....l..late ;oin, MGMlls rid,1tIa iiltte,'.t -ew it..I-li.iiiiiii t..(uial r -- ý c ...

l..irvi

t. ian

.i1rntt...1it. C(i:;aie of tulAtished guides rtadyble olbtainld lIv written request aidacating the INis iju li1.. ii tem .itm (l artaila ,it Iii t 1a1111m1la .Ilrer O , as,i i.'.

its .,il tie iPa divisions desired to the UtS Nucltear Regultatuor Commission. W a~shtng lor . 0 C

tImulai ly usef ll iii t hli llillii 'niri. l .ti .t....i.. y IV.,..a.... IOt2 5, Allen tion D lte . lol. Office of ,SlandaidiDeveltopm ent

The BBRV system, developed in Switzerland by The VSL strand system was.developed in Switzerland.

Birkenmaier. Brandestini. Ros. and Vogt. is a wire This system employs a wedge anchorage for strands.

system used in both concrete reactor vessels and Each strand is drawn through the openings of both the containments built in the United States. The main bearing plate and the anchor head and is held by a feature of this svstenz is the. use of cold.lormed two-piece split cone wedged tightly against the inner buttonheads for direct bearing at each end of the wire. surface of the anchor head. As an example. the conttainmnent of the Rancho Seco Nuclear Generating Tie prestressed concrete reactor vcssel (PCRV) of the Station* in California employs the VSL system with Fort St. Vrain station in Colorado employs the B3BRV tendons consisting of 55 strands. each tendon developing system with 169-wire tendons developing approximately 2250 kips capacity.

2000 kips capacity each. A number of 2-ontainnienls utilizing the BBRV system with 90, 163. 16). 170. and The Stressicel S/Il multistrand systemi was developed

186 wires per tendon have been built in the United in the United States during 1967-1968 by Stressicel Slates. The wire diameter is 1/4 inch (6.35 imm) in all Corporationi in cooperation with llovwlett Machine cases except fur the 163-wire tendon, which uses 7-mm Works. The system is characterized by a three-piece

(0.28 inch) wire. slotted wedge cone that grips three strands in its serrated teeth, with a number of wedges in a single anchor plate Strand Systems. Strand systems employ a number of making up a ittllistrand lendon of the desired size.

"'strainds" that are bundled into a tendon. A strand is made tip tof a number of factory-twisted wires. As at, example. the conlainment of the Three Mile Stress-relieved strand is made in two forms. The first is Island Nuclear Station Unit No. 2 in Pennsylvania the seven-wire strand. which conforms to ASTM employs the St resstecl S/Il multistrand system coisisLing Specification A-416. *'Uncoated Seven-Wire Stress. of tendons with 54 1/2-inch. Grade 270K. 7-wire strands Relieved Strand for Prestressed Concrete.- The second per tendon, each tendon developing 2230 kips capacity.

forni consists of larger strands Iltat are made of larger individu al wires anid may consist of more thian seven The Freyssinet systemn was naimted after (ie French wkires per strand. vhe larger strands are not covered hy engineer Eugene Freyssinet. who itivented the anchorage ASTM spicifications and have not been used for the device in I939. The original anchorage device was for a construction of nuclear power plants in lhe United wire system only, This is a comn monly used commercial Slates. system. The anchorage consists of a male conical plug and a female conical recess. The plug. with the wires Strand systems have been introduced in the construc- spaced evenly around ils perimeter, anchors tile wire by tion of nuclear power plants by Strand-Wrap, N'SL. wedge action.

(Vorspann System Losinger). Stressteel. Freyssinet. and SEEE (Societe d'Ettides et diEqtiipments d'Enterprises). As a result of market requiremenmts and subsequent The last two systems were considered but have not yet developments. the Freyssinet system now also has been used in the United States in nuclear power plants. available anchorages for strand tendons and other shapes Both the Freyssinet and SEEE systems have been used in of anchorage devices different fron the original one. The Europe on concrete reactor vessels. swame wedge principle for ancho*ring the tendon is retained, however. Concrete reactor vessels have becn The Strand-Wrap system has been reviewed and built in Europe using the Freyssinet strand system with a approved only for applying hoop prestressing 1o soine maximum tendon capacity of abouw 2000 kips.

PCRVs in the Ltnited States. The basic principles of applying ltoop prestressing to the PCRV by the The SlEHk system was developed in France by Societe Sirand-Wrap system are the same as those for d'Etudes Ce d'Equipnments d'Enterprises. The system conventional prestressed concrete tanks and circular features threaded anchorage fittings extruded onto the liquid containers ithat have been built using wire-winding ends of a group of strands. An anchoring nut is then machines. Steel-lined circumferential precast concrete threaded onto the anchorage fitting and turned tightly channels are anchored to the outer cylindrical surface of against (lte bearing plate. A tendon is composed of one the vessel by reinforcing bars extending radially inward or several such anchorage fittings on a common bearing from the precast channels. The strand is anchored at one plate.

end by means of a tapered wedge grip in the rib between adjacent channels and then wound around the vessel at Bar Systems. Bat systems employ a number of ihe design tension for a number of turns and anchored in high-tensile-strength steel bars that are bundled into a the next adjacent rib. Each band of circumferential prestressing consists of multiple layers of strand wound onto these channels. Each layer consists of one *The Irey-yinet. SI-l-, and VSL systemsl were formally contittuottis length of strand. A maximum hoop prt.m-niled is allternatives to Ile previomstiy approved IItIRV

prestressing force of about 6600 kips per linear foot of system. ThmeV'SL syteim was chosen by Mhe applicant.

Consequently. the Freyssinel and SIE systems were not vessel height is being used in the design of the PCRV rnvicwed by the NRC starf with regard to their acceptability for head region of the Dehmarva Summit Power Station. use in nutclear power plant Containments.

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M

tendon. "l Ie bars are mnade front an alloy steel been easier 1o acco inplish tltough lite use olftngrouted conformiug to ASTM Specifications A-322 and A-29. tendolns.

A-322 is a general specificalion that covers only the chemical composition of many grade dcsignatioi., of alloy steel bars. and A-29 is a specification for generl

C. REGULATORY POSITION

requirements for hot-rolled and cold-finislted cat bun and alloy sled bars. No ASTM specinication covers the This regilatory !!tuide .*ovcfs the generic qualificatiors ininimuni mechanical and physical requtirementlls for the otf po*st-tisiiolned prestcissih*g systenis lised in colnclete prestrcssing bars after processing. as in the case (if' wires reactor vessels and conlainrlieits. with Ilo) atlerlmi to (A-42I ajnd strands (A-416) and it is for this reason that extenid its scope to design aspecis. The accepiahility ol a speciticati )i* was written by tre Prestressed Concrete any posil-ellsiolled prestre.Nsirig syslelm ill conjunction Institute. with a specific structute design woitld lhave to bie evaluated on a case-by-case basis. Any proposed system Bars are cold-stretched and also stress-relieved by heat submitted for NRC approval should consider tile treatmenu Ito produce the prescribed mechanical following:

properlies. Bolih defornied bars and smooth bars with threaded ends are available. hut only sinooth bars have 1. Post-tensiuned prestressitig systeirs that have been used for unclear plower plant conStructioll in tihe beell approved in previous nuclear powcr plailt license United Slates. applications are regarded as accepted systems. See Table A for idcntification. When tie clain is nade by ail The Stressicel Corporation in the United States applicant that tile prestressing sysienr proposed is ail employs a bar system. The bars are stressed by mneans of accepted systei., sufficient int'[rination shouttld be pro- an hydraulic jack that consists of a coupler and pulling vided with each iipplication to demonstrrtc that tile bar. The normal commercial tech tiique for anchoring system proposed is the samne as tile on*e that was uses anchor nuits. During stressing. t[le anchor nuts are approlJd iii !.ý'\vious muclear powel plant license ;ipplica continuously screwed down on washers and bearing iions. Pri:,-r approval of any system does Inol relieve tile plates. and the prestressing force is then transferred to applicanm of the responsibility for demonstrating that its tile anchorage assembly by releasing the force in tihe svslenli leets all tle requirementIs of thle ('*Lc for jack. Wedge atn' grip-nut anchorages are also available to Concrete Reactor Vessels and Containmenls.41 anchor the bar; they possess tile advantage of being able to grip the bar at any point along its length. 2. Changes in prestressiig element materials or in aichorage items of previously accepted systems that The containment structure of H1.B. Robinson Unit may require replieatig the., system peritrtnance tests are No. 2 in ilartsville. Soutlh Carolina. employs lie identified in Subsections ('11 and CC, Article 2406 of the Stresstecl bar system anchored with Howlett Grip Nuts. Code for Concrete Reactor Vessels and Containmntetils.

The tendon. comuposed of six I-3/8-inch-diatnuter Stressleel bars,. develops a cap',:ity of 1428 Kips. 3. Any new post-tensioned prestressing sysreiri should meet the requiremenls set fo7rth in tile Code to, Concrete Reactor Vessels and Containments.

Grouted and Ungrouted Tendons

4. The use of any post-tc*sioned prestressing system should permit the applicatio of ail iriservice All of the concrete reactor vessels and containments inspection program that will verify the continued designed and built in tie United Slates use ungroited functional capability of tile structure. Implemenlation tendons except for H.B. Robinson Unit 2 (bar tendons),

of this program should not degrade the quality aid Three Mile Island Unit 2 (strand tendons), and Forked reliability of the post-tensiorled prestressing system.

River (strand tendons), all of which were designed for Regu.latory Guides 1.35. "'tisetvice Inspection ill UnIli.

grouted tendons. On none of these, however. has desigin grouted Tendons iin Prestressed Concrete Containumen credit been Oven for any bond of the grouted tendons.

Strulctures.' and I.90. "Inservice Inspection *f' Pre- stressed Concrete Containnient Structures with (Grouted Whether grouted or ungrouted tendons are used, a Tendons." should be consulted for recommiendations means of determining ile functional capability oif [lie concerning the use of ungrouted and grouted concrete structure during its lifetime should be available. This contlainrents, respectively.

results in a need for reliable quality assurance procedures for t[le tendon installations and a need for a reliable structural inservice inspection program. To date, this has

"ASME Boiler and t'ressure Vessel ('ode. Section Itt. Division 2 (tile latest version, plus addenda, as endorsed by t(ie Nuclear

""(;uide Specification for Post-Tunsioning Materials," PCI Post- Regutatory Commission). This Code is currently under review Tensioning Manual. Prestressed Concrete institute, 1972. f'or endorsement by the NRC staff.

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D. IMIVPLEMENTATION porilons of't ile Ct ininlission'~s reglIluc ions. tile Ilethod dec~ribed hecrein %%ill be used inl tile evaluationt of suhbmittals for const ruction permit applicatiouns do cketed TheI. purIpos OfL r 1 iSisNC I io is ito provide ii tort u (on after J1Liie 30, 1976).

(o alpp ic amus autd li elscees regard ing tie staff's phlans for using~l this regullatory - title. I all applicant %%ishles wouse this repuiit:Iory lideill.'h developing submnittals tku applicat:ions docketed til or

"*c itlt lhoste cCases ill which theileaplicalt proposes bel'ore JuIte 30. 1976. the pertinemn portlnuls oi tlie aft;dernaltive metho)d fotr co*mplyin,, %%ith spec.ified application \Mi] lhe evailaied oin the basis ol" this puide.

TABLE A

STATUS OF SYSTEMS AS OF MAY 11975 use(/

In US. A'tich'ar i

IRr i~ c iv i; iahl it

,e',s A'RC 1'oivvr I'lants

1Por I. iccnlsh~ii Revi'it' staff 7',) Dim,

.x x x

00, 1w), 170.

t,ý(. Wiles

(1/4 ill. r0)

163 W i 10s VS L. x x x x

( 'sranlds)

St re~sscel N x x x sti ra nuls)

x ist rall ()

x

(5stratid)

strcssicel x x X x

(6 1-.3X it.

I

POW'R Strand. x x x WVrap UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON. 0. C. 20555 POSTAGE AND rccs PAID

OFFICIAL BUSINESS U.S. NUCLCEAR RCGULATORY

PLNALTY FOR PRIVATE USE. S300 COMMISSION

1.103-4