ML19246B052

Reg Guide 3.11,Revision 2, Design Const & Insp of Embankment Retention Sys for U Mills

ML19246B052
Person / Time
Issue date:	12/31/1977
From:	NRC OFFICE OF STANDARDS DEVELOPMENT
To:
References
REGGD-03.011, REGGD-3.011, NUDOCS 7907110282
Download: ML19246B052 (9)

Text

Revision 2 December 1977 jm f

U.S. NUCLEAR REGULATORY COMMISSION

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@f"# )REGULATORY GUHDE

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041CF OF STANDARDS DEVELOPMENT REGULATORY GUIDE 3.11 UESIGN CONSTRUCTION AND INSPECTION OF EMBANKMENT RETENTION SYSTEMS FOR URANIUM MILLS A. INTRODUCTION their au cptabihty. (iuidant e on operanon and aban-donnient of ths retention sy sicm n presented in l.It h lis cilset w hei pl e sc e s se s tir ret;ncs urantiin; sC paf atC M ill d e s ones in a nulhng operanon is remured by s 2n i of in

('i R Part 20

' Standards for Prot et o on Ap.u nst B. DISCUSSION RaJiainin.

tii n uk e c \\ c ry rea siinabic c tt or t to in.u n-I IlJ nlllling i'l llIJrillin) i'IC s re sult s In lhe prlhlut lai n I.iJ iain 'il c\\posures and reicascs of raJioactn s tiim sit larce iidunic s iit inpuJ.ind solul w astes itail-Inatcrials in c!!Inents li e unrestrh ted art as as hiw as Ings! Ihesi tallings are usliall) stiff ed bt blnil niJil-is reas.:rubly atlues abic. takine into autouti lhe stale ina l; ret.oning strut tures. tollow ing the pras th e of iit tec hni loes and the etiineinnt s id in:ph n entents in the lhln-urahluni niining industr)

Ilic design.ind Iclation h berctits to the pubih he.ilth and saf ety in t eiristilh tlt MI ist I.illin g rett, nili n st rus tur e s ha\\ C in ll#c i

.iddii n in. S i (,l R P.irt l uii, 1 n s irimnie nt.il R a.h.i p.i s t been baw d Ic n13 on nuning expcrien, s uuh tuin Nt.nular ds ti r sut l car l,iiw er ( )pe rat ti ms,

i rc littlJ li s t ilt d e sig il timt epts lhese cinplIl cal.jp (pures that the nustnlurn ann'ul radutnin dose to ir pli at Ilc s Ic sulled 'n \\ a rli ells flilning d.th) illishaps and i

dl\\ ld tl.tl 11!C11lhe r s int the ptiblh restilting t riuri t uel tallures i Ret s. I and 2). 'I he f.ulure sit liut tahi ( ~rcck

)i le ope'atnins be linlited lii

_3_.s nullucms lii the

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!)Jin in WCst YlrpinlJ e\\ Jrl Icsulled lit t}lC l' S ('tirl -

w hole bisdy a nd tii all organs c \\ cept the th\\ rind.

w hh h milst be lunited to., 3 nullircins l Iquid and quh kly pawing. na!!onal d.un salc!\\ law at-eiess lCe ting all w atJr-impitunding strut tures in e\\tess t il siilld w.t st c N ( l.tlli n g s ) eCI JratCt! 1 the ur.in'uin nllll cit!lCr 2b tCcI In llClpht tir.MI as rC lCet til InlptW!ld-Ing i pciat u m cont.n n radio.i ils e nutetuls '.) c h ess i

ment tapatity ( Ret T) ot the a m hargs hnuts and are.cner.dl\\ Wnfm d by an Cl!1barsk ulCn! ICit ntliin s\\ sitnl l'raflluni 111lll tallines, unlike nhist in m nr.t n>u m IIH rt lJlhnps W ntnu W ncentr.Hu ms of raJioa tr\\

[hls gun'c dew ribes t

mie engineering pr.h t h es s

filatcIlJls In ekt e% ist the Jlhiw ahlc dl%INtrpe !!!llits and methods._ cnerally t ensiJered satisf at nit y f or t he (Re! 4r i urthernnire the iniist slpnit h ant radioac deslyn. t s i s t r u t ili e n, and inspct tiiin ist ca-th arid tl\\ c Cle!n 'n! In the tailirips i s raJilin1-22fi. i. h i, !i h a s rou x till emb. ink ment s used f or retanung uramum null a half-lif e of abiiut IMH) y ears I Rc t 5).I hs rc tiire, it tallines lhes r e s t. ll t ront Ic t iew Jnd attlon on a Is neicuar\\

thi se tailities tii prescot ;ir numb-r of spet llic t ases and reticct the latest general

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timtrid the ir release lei the ens nonrneril niit iml) due appnw hes tii the problem that are as septable to the me the operstmg hte of the null. but also t'or genera-NR(. stat! It Ilcw It'.fi rillJtl.in Ih.It illa) be de\\ Chiped i

in the future results in alternatis e inet hiuls. suth

! mes itidhate substantis c thanges t roin pic\\ n:us me t hod s w ill be res lew ed b) the stalt to deternunc issue USNRC REGULATORY GUIDES s

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• w tions alter milhng operation has teased.1 he em-istics. Ihe chemical quahties of the taihngs and l

bankment, tourulation, and ahutments nced to be sta slurry must be assessed to deternune si a w ater-ble ulaier all toiuhtmns to pres ent the uncontrolled wilet ting sy stem is nei ded to pres ent unatceptable 4

telease 41I the retained u ater iir sen1itltiid railings Am nureani dintaniinat sin restilting t riin) seepage tir SCepage trtifil the t.iillNp pittkl. w hic h ti>iitains dis.

surtme w ater rumsti.

Vit t e ' f ailiuni and anther tttsle substantCs (NCt 5 ).

St]hy g { ace inseQigaliinis at the site til the reten-s

'l e c u s til bt < t hntitilled Lindei ntsIfnal alld se s ere thin s)' em and at pt Wsible Ihtfrt>w areas liced til be operatine tonditions to pres ent the posubihty of un-adequate to deler: une the suitabihty of the founda.

J < t e plabIe c t111t anlliialit tu til t he p ritu nd w ater t)I tit'n and abliIWCnts, lhe rC4ulrCinCnts til it'lindalltin nc.uby streamt W md,md w ater erosion of the tail.

treatment. and the availability and charatternths at I ines needs to be presented durme and af ter the mill-embankment materials l he insestigations should toser clawitication. phy sical and chemical prop-l my operation erties. location and estent of soil and rot k strata, and

()bs ionsly, f at tois pertauung to saf ety. t ont.unin.i-s ariations m groundw ater conditions l ioll..ind ein ironmental dam ige dClermine lhe basic lh t undation comniions must be deternuned to r e q u ire nie n t s in plannmg and tonstructing retention mm the Mequy of subunt Ae mataials to sup-sy steins I ti at hles e the bJuc icquircinents, the de rt the dain without f ailure aint w itheiut esccwis e sig!) Illlist be based im a theiriiugh unJerstaruling til ti tal iir ditterential settlenient. I he permeability sit i

hi th the pct 'et hnlidl problems insolsed and the rC-t o uild alitin sibils and rocks a ust be a%Crtained Ill CU i

glllf C!ne r't s til the Inllling (*peralis m.

tilnate the anh*unt (91 scepapC. pipiag ptilCntial. Jnd, it ne< essary. the methods of scepage control. 1:1e l he latest ad umce s m geotechmcal engmeerme-as ailabdity ot suitable borrow mater' l f or dam con together with engineering espeliCHte and knowledge struition must be assCssed, td We nato c on odCf alb m as ailable in the field til w ater stiirJgt dan 1s. tan be the Otndru lism sC4uence and WhCdt'!C uscJ in the design and construttion of retention dants t he bJsl< Oinseptst it cinns entii na! w alCr slt'r-i age dams un be suitably modified to produce et o-

2. DliSIGN \\NTISSIS nonnul deugns that will ensure the stabihty of the relcntitm N)s!Cni aiht mininlal OmtaminJtlinn it is imptlitant that design Jna!)sls Oinsider %IablI-ily. sCttlenient. seCpage. and hyditihigic analy ses Spetitisally, the design needs to ensure that retention

1. Gl{Ni{lt AI. Pl. ANNING AND Di{ SIGN d.un tailure w ould not ot t ur. H ntorical records CONSIDI:lt VilONS i Rets. ti m indicate that most t.nlures ass s tated with Hecause the pruns tun < tions of the retention sy s-anh or tailing d.uns are aused by osertoppmg by tem are to store radioacin e sohds and to pro s id e Good u atas, nouon. piping m either the dam or the temporan storace of wnt.umnated w ater for clarifi-toundation couapse of the dew atning t onduit. foun-catli n and es ap TJtlt>II. it is liilpolitant that the sy stCin i

be desiencd and construt ted to rem.un stable f or its mtende[Ihie It must pmside the required storage at 2.1 Ilydrnlogic Analpes 4

any enen tune.md it must pros ide sutt h ient wntrol Ihere w dl alw as s be some cart hment area con-I til sce p.iee It s pres ent unacceptable Omtalnination of tIlbutine rumitt I

! aJpcem land. u aterw ay s, and eroundw aters it must tN f allint' identitm n uem. T his may s ary f rom the area of the sy skm itself to a sub.

.d so pros id, et t ectn e means to pres ent u mJ and Wntial area incorporating the drainace area of s af er citWien.

q7 ggg g g, 7;, the sMI rins w hich a n tentnin

f S' ige construs tion w it h the treeboard W,u nt.uned d'un is t onstrus ted Substantial funott solumes and tlo w s Can result f rom he.n y precipitatien or snow -

sulhclentls a bN lhe storaec les el mas be wnsid_

eied t he use et tearse tail'ings as einbankment 1, melt osa relatnely small catchment areas

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m iterials n not deurable becan w the t.u hnes c ont.un 1he mnunum runott used m the desien is usualls radoat tis e mJterials that ma) cause unJcceptable gllgj gg g jjjg

])gq g g j.lggj g g[)l. y ggjg p

ens ironmental unpacts the largest flood that need be analy /cd. regardless of Iktalled site ciinditiims. includine climate. hs.

u hetkr m M a P lw e is pnniM.1he magnitu&

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d oli'es. cetilt le s. and selunobles, fleed tti be

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u s'ssed an[1 their impact es aluatch Det.uled knowl.

alipNd in the FluNd States for the past 30 years is edge is needeu of suc h phy sical and methanical prop.

equal to that of the Pmbable Mnimum I lood' at the eftles of f oulhlation and enih.inkment materials as

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cilinit it atitill, sbCar strength. tiinsi lidati.m. permea-i w N e we. let trom the w e c cre

+nen oruma bl I s. sC mCnlaIlon, Omlpaktitin. piping alhl (rat k-p

,4 ' c ( Cd hi dri'l T h if!MD' lhd! Jrc TCJv tdNi p s4

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ing suveptibihty, and u ind w ater crosion c hara ter-Ne m lhe re m

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site of thi dam NiethoJology to estunate the l'roba the auilable shCaring resistanse along those surlaces ble N1auniuni i lood is a\\.nlable in Reputatory GuidC

~Ihc rano of the a\\.ulable shear strength to de\\chiped 1 59

' l)e s ig n liasis Iloods f or Nuclear Pow er nia\\inium sheer stress pn es lhe tat tor of saf ely

Plants, and othCr pubht ations (Ref s in a.u! l i k 2.2. ! A1Cthods of Stabihty Analy m I or snull rClention danis built on isolated strcanis in areas where f ailure w ould neither jeopardi/c 2 I I hiarn hiahhts.lnalt m hunian hte nor t reate dama; to propCrty or the en\\ -

it 'nlile nt be) n Mh! t he spt ' fist 'r's ICeJI llJbilitlCN dnd ll-I here.tre tilJn) lilCtIhkls usillp the Ilnlltlnp equl!lb~

n. int ial t apdbt!lllCs. lCW O nnsC r \\ JIl \\ C lbkh! dislyfl rllini dpplti.ls h !)C(dllCd discll'It'n cdn bC b'ulhl lli

( i l t e r l.1 In d) be lised in 'he dCslyn I!t'% e\\ cr. t hC

\\ Jiltills pilbI cd!liins ( R Cis 14 lh)

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seict tion of the daign flood needs to be at l cast n:ay be ton \\ eniently groupCd inoi three categories-t aitllpatiblC u lt h t he.'u h!C!lnC s sCl !s tlth b) t he ('t'rps a /.i n tmn ( ni le E tho.I I his method ainsh!Crs til I npillCeIs (Nel l _, l.

IllJ Clitire s!Idine blot k as a ricid l rec bod \\ and ll decant or other ICt lallll s\\ stellh hJt e not bien niakes assumptions ICyJrding the disIrlbution ol nor-designed specllis.III) til [J n the '!Cslyn lb b'd, l'tflCr nlJl strewes dlL'ng thJ ldlIurC surldte I hls Insthth!

Illc a s tlI C s flced til DC tdkCn I hiWe l't her IllJastf rC s can tin!) bC usCd tti C\\ Jludte t.llluIe sllrlJt es th lt JIe illd\\ b. tine air a t o!HbillJtlon ol the fillbm ing (trtlcs or sing lC stralpht hnes ( he lop.trlthmlC spird!

Sitif t ny the W ht*lC \\ t'lllllie til l h'n 4l Illib il l a

Sullit lC nt treJ bablid sht'uld JIw J) s he.1%dllJble ta) b 1/i f /h q / e./ 3 /is e t. '] })) s incthtu! di\\ iJes the f ree prti\\ ldC the nC(CMJI) sttirJpc cJpds it) W it!h'ut l'\\ C r-beidy in[gi nljn) \\ Crtly Jl dit es, and the Cquilibriuiti ist ttipl11ng thC dd!ll Cash N!]se is colhidCICd. I be bCs! kntM n Jnd nunt u ldCl} used \\ Crsit)ns til lhis nlCl}h'd are thC SW Cdish l

b Pro \\ iJine a spillw ay or dn ersion ch mnCls lo h rcle N1e t ho d. NtoditiCd $u edish \\le t hod.

(t'n\\ c) f untill % dtCr %1lCl} pJst thC ddin Sunphtied linhop NICthod, and N1orgenstCrn-Price lies ause of the louc liiture of the nnpounded ma Nierhod.

tCrld! 1 ls pref erred g,

g, l)CtCImlndlli'M t 'I the IrcCbtidld fles CuJr) at.i n )

the l.lllure surldCC cJn bC %1 tis lJs tt'rl!\\ lpplll\\iniated a se rie s of straight lines usually two or three lime to store flood runott will require inlormation en by pilnd shirage \\ Cisti s Cle \\ dtit'll. allticipated embank-lines filCnt sClllCillent \\ ctsus tlnic Jnd thC CilCt tl\\ C helphl

.l he nlcthod til slices ollCrs thc best appri Jt h It'T i

()! h ind eCnerated w ak es I,ris edures li>r deterniinine the niinlillum lrCCblidrd dfC prCsCntCd in NCICrCn shape of tinluie surtat e (Rets. 17 and ISI h hile the lIl ll Is IIHptif tJllt that the CnthJnkment Construt flon IIiction tircle nlcthod can pro \\ ide siil ti t i.in s in w hCdule Cnsure that this require:! trCChi ard is alw ay s i

htimtipenClius %)ll, it is dlllit ult tli Jppl) these Jp-J\\allJblC proas hes aith tontidence w hen the soil is slr titied or AJequate slope protection is needed to guard the

/oned ~I he w edge method can prm ide reasonable so-CmbJnkWCnt dp unst B lnd Jnd c ater Closmn. weath-lutmns f or situations where ihe tai lure surtates are Cling. Jhd.JC ddnldpe. b Cthilds It'r praiICe ting sb'pe N tiimpt hed L'I st rdlf t !!nCs h

Inc!llde Juniped clprap precast and cast.in-plate tiin

(.(Wiputer u)llltions to the inethi'd of slices hd\\e t rete pd% Cn!Cnts, bittiminous PJ\\ Cinent. sol! Lement.

been de\\ Cloped ( Ret t h. ). fly usmg tomputers. many Midding Jnd planting. I he neces%iry upstream sity'e lihire awun1Cd Cllnditiiins arid tailtire stirlas es can be prtiteClltin depends ini the e\\ pct ted u irh! \\chicity and Irled..I he Clf es ts all pthslb!C \\ arldt iims in nldterld!

dilration and the st/C Jnd contipurdtion of the reser-

[TL'perties can alvt be e\\ aluJted..I he tiniiputed re-

\\ oir at the w ater-surf ace Cle\\ ation Ihe necessary suhs neCd to be t hecked w ith respect to their rea-dow nstrt.un protection depends on the e\\pectCd ero.

Minablenew Jnd clin 1patibillt) W ith the design prise-sitin til sur f dt e runtill Jnd W ind Crinnm. Ref erenses dures Jnd critCIld

10. ml 13 pro \\ ide methods anJ <riteria f or the selec-tion and design of shipe protections.

y y. I, h. iww hiabilu t.lwh sis t

In areas w here embankinents are subjected to seis-3.2 Stability Analys.is nuc dnt urbans e s, analy ses should be made of the Sltipe lJ1lure ticcllrs W hen ;10 (luter peittllin t >l an selsnllJ elletts (in the dJnis. SelslHli \\ lbrdtllins can embJnkment slldes dou nW Jrd and outW Jrd W ith rC-cause hquerition of saturated or nearly saturated spect to the remaining part of the Cmbankment. Tl.c loose -ands and sensitn e sihs (Rel it t he dynamic shde generally oscurs ah ng a f airly well defined shp shearing strcwes indacCd during the seisunC e\\ ents suitace. Stability analy ses in\\ ol\\ e comparing tbc can cause cuewnC def ormation or dntortion of the shearing streues along ptitential t ailure surt' aces w i:h enibankt'iCnt --C\\ en shCar f ailtire ( Ref s l9and D)).

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scisnuc stahihty an.oy ses of embankment dams are supp!cniented by laboratory tests or usine d t.nled

( s in s cilt iiiin all) n!.nle using psCudislatis nlCthiH!s pii'urh! lesghinse analyses tiinibincd u ilh dy n.iniic i

(Nct 21) In t hiN Jppribish. IhC stahllit s i't.1 lh itCntidl labi f ah d) IC st W p l'.ls! C \\pCrlCns e plos Ides the most i

sinhnginass n deternuned as f or static loadmg t onsh usef ul gual.uh e on the probable periorm.nh e et suni t!< in s..tni! lhJ c t f e( t s ill an Carlhquak C.IIC t ak C n i!lli.

IJr Mi'l dC(h hlIs. wilile tIk g raiiind r C s piinsC Incitni !

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.u timnt in the wmputanon by nh luding an equn a-prosnics a means f or considerine the cltctis of the Ic!;t Ih 'rl/i'ntal fiirt J at ting I'n lhe lh'tentl.ll s in!Ing Jnlpilf th!J J!hl t!nle histi r) til t he C,lrt hquake g!tiuihl i

l he hi,r vontal tort e represennng earthquake motioin. the in 4 t u sod t har.h tcristh s. the os cibur-mns e xprc ueil as the proJm t of the w cipht of den prcuure. and the groundw ater t ondno in ettetts is the slutmp m.ns and a scismh t ocii u ecut ihe s aiue 2 2 2 lemhng ('ornhtions and I m tor of halct>

of the seism.s t oct t h ic nt is nor nully sclet ted on the b.nis ut the,cismh ny of the it gmn m winsh the dam

\\ t.uhng dam ant! It s f oundation.nc sub cs ted 'o i

is to be sonstru< ted shcar streues imposed by the w eight of thc dam and

, rg< 6 y che inertia tones arc

- ths filhne of the pool, scepage. or carthquake bs I)urme cartinpiakes lort es l he 'c a se s f or w hh h stabihty an.dy ses are ia indus cJ in cmtunkments In i.criani fones of an em

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bank ment. the mettia tort es may be sutt u rently laree

.nul ruay is t ur a sutth ient inunbcr of times to t ause a /ndolion.

nnon. Analy ses of the upstream lic r !Il a n e ll t displas e nie nt s l'ri N tij u r e s ti r e st!nt.tlin e i

and (. in nstream sh. pes are needed f or the end of ton-the inaemtuile of th< se ihspl.h eme nts bas e been pro-strus tion conditions it the embankment and its foun-pined b) N.ew nlar k f l$ct 22) Jnd b) ( h uldulan Jnd

<!.itliin Jrc tiimpined partiall) tir ciltiIcl} t d impct s i ScCd ( Nct l '))

Ibilti sit thesc pri% ctllites plesunic a iiu s v ill s l he lirkiin stilidated undlained i t I. I shcar k now ledge i,t tt t tune hntury of the inertia tort es s'rC ngt h s hiillld be u sed in t he a naly se s fi >r sliin -

.h tmp en an embankment dur mg the carthquake.

draimng sods. u lule t unuilblated dr.nned H.Ib shcar I hoc appro.ula s.nc m..re inuls ed th.m the, onsen st:Cllelh shalulu,,' used tier tree drJinine vols w herc s

(ninJI nlelhiMts and has e been used sih t eutully tii

' pore pn ssmes w ould not des elop' euess predh t she surl.u c displa cments of embankments of dry tohesmnicss soils How es er tot sods in w hh h b />ar tml p, 'l n ah s r. ads s, ra o Analy ses of pore pressure t hanges as a res uh of the shcar str.uns the upstre.un slope are needed f or ses cral mter-inJu< cd bs the carthquake, determiinitum or apprii-mediate piwil stages w ith ciirrespiinding src ady scep-priate s alues at th. 3 icld.h t eleration bet unes dit -

Je tondnions. i he ana'y ses ascount tiir rcdot tion m t h uh citectise namal stresses w here pore w ater preuures that des cheped during o'nstrlh tlon or tilhng are not in dealing with saturatCd (tiheslidlICss M ill s, thC dissiptM Nline ik subqwm plial poil tidi-dynannt an.dys.

pros ed ures des eloped by Need hm I W ima e m'W Nm MM A mwhd A d

-' ll prm iJe a basn f or aucuing the stabihty undrained 4(.l i shear test or s onsolnlated dr uned IRet JMd i! cit tr niatilin i t the enlb anknlCnt during Carlb-

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[ g g y g g g,,,g y quakes I hn ty pe of analy sn may be uscJ ti pred h t t aW hM be detemd n a tm tmn of the des clopment of the lupact h tion une and the an-d anim t h ipated mos ement s. def ormatnin. and stabihty of the embankment and as f oundation. How es er. good c.

tla u"m m stora n pool n ith sti ads u n pa c.

cugincering tuJgment based im adequate dat.i iniist be l his tiinditiiin riia) des chip and niay be t ritical tii e scrt ned m the elet tion of sod s har.h iernth s for dow nstream lope stahdity A flow net w ou!J be use m the analy ses. in the det.uled steps f ollow ed to helpf ul m dem rnumng the phreatic hne and seepage

i. tind ttc! tih anJ!)sCs. and iii the es altiatum iii the re-ti rt es Shear strength selet ticm shiiuld be the sirne as i

sahs obt.uned ir the partial pool w ith steady scepage condition A detailed dnm ussion and apphcable guidehnes f or d. / a r thivia to In areas sub ected to senmic i

seismic analy sn and Jesign of t.nhng dann tan be shotks, approprute earthquake f orces need to be f ound in Ret'erense 24 added onto the presious loadmp to"Jdoins m the sta-l l 13 I te, ta, tn n />ota nual / s alaarn,n

'lhe use of a tutor of saf ety m stahdity analy ses it is iillptqtant that the pinsibillt) (d Ilquet h inin el shiiuld alhiw sutth ient margm f or s ariations betw een f olindain q. unis be es alliated b) nlcJ n s t)f'

' state tit -

the paranietets used in design and thto. e sisting in the-art, pra edures insols mg senmologhal and geo-

.hc field and c< nideratom iit the limits i t strains.

i higiCal ins eslijatnins. Ibi objectis e i't sihh Ps alua-M J n) stills underpsi r elatis el) 1.irge plastic strains as tions n to estab,. h carthqaake deven parameters for the apphed shear stresses approath the shcar strength m

use in the anal,ses and the dy nannt rating of mate-i>lthe unl.

rials. ProccJurcs urrently used f or n aluating t

!!quet.h tnin potentiJI are basCd on el!her s'Mnparing t he torisequerne tit' a f ailure, the tolerable limits the past experience w it h similar soil depissit s sit strains. and the degree <>t timtiJcncs in engineer-142 256 am

ing parameters used in the analyses all need to be The graphical method o' plottmp thm nets is eco-umsidered in choosing the f actor of safety. T he nouncally and easily perf ormed. and it pises suffi-cient y accurate results for many seepage problems.

,oininium f actor of vfety appested in the regulatory l

position of thn guide presumes that the stability anaksis has been sutticient to locate the critical fail-ure lurf ace and that parameters used in the anabsis

3. CONSTRUCTION METilODS are know n, with reasonable certainty, to be represen-Construction methods f or mill tailine dams are ratise of attual conditions of the dam and its founda-losely related to the plannine and operation of the tion. Otherwise, higher tactors of safety w ould be re-mdl. Where a tailine embankment n constructed in a quired.

single stage of natu'ral borrow materials or merbur-22.3 Settlement Anah ses den and w aste rock, consentional procedures for

~

earth anJ rock-fill dann tai. be used it the foundations beneath an embankment conust l of layers of comprewible soils or weathered rock or it Where a taihng dam is constructed in staces one the bedroc k profile is sery irregular, dif ferential set-of the following three methods is used. (a) upstream tiements could result f rom unesen loading or sariable method. (b) dow nstream method. or (c) centerline thicknesses m the comprewihle site conditions. these methi l ditterential settlements may cause longitudinal or W uma mmmim mthod is the oldest tranuerse cra.ks in the dam that could lead to sub~

MMk Mug ud h a nmA k surface crosion and dam failure by pipir 4 ped procedure f or disposing of the tailing as eco-

't he maenitude of the anticipated se:tionent can be nomically as possible. An initial starter dike is con-estunated f rom the results of laboratory conso!iJation structed at the downstream toe of the ultimate dam tests on samples recosered f rom the compres ible with borrow materials. The crest of the dam is raised f ounda; ion strata and remolded embankment mate-by placing fill materiak in successise dikes located rialv t he rate of settlement can aho ne estimated on the upstream side of the imtial starter dike. The floweser. the potential error in estimating the time centerkne of the embankment crest is shif ted toward f or settlement to occur is appreciable, since settle-the upstream pond area as the height of the dam in-ment is influenceu by soil drainace that i. controlled creaset The dow nstream toe of cath subsequent dike by minute geological details that may not be detected is supported on the top of the presious dike. with the during the f oundation insest;gation. All predictions upstrea'. Fortion of the dike placed oser finer tailings on the rate and maenitude of settlement and the (slimes i within the impoundment. These slimes, t hange in pore w ater pressures need to be checked b) place. hydrauhcally, hase a relatisely low shear field instrumentation. Predictions based on laborator) strene h and remain in a loose and saturated state for data can be modified by actual meamrements to pro-man [ years af ter deposition mef. 25L As the height side reasonably accurate lone-term estimates-of the dam increases, the potential fai3ure is locat if compressible soils are thick, it mas be necessars at an increasingly greater distance t rom tl' to design the dam to absorb the anticipated dif feren1 dow nstream f ace and through the slimes. As a resuh tial settlements. If considerable total settlement is the outside shell contributes less to stability as the espected, the dam must be built hicher to allow for height increases. The retained slimes are sutliciently the settlement.

loose and saturated that they could be liquefied to cause the failure of the dam it subjected to senmic

.2 A Seepage Analyws shock or blasting.

Seepage analyses evaluate the ef fects of seepage With the dow nstream construction method, an ini-on the stability of the tailing dams and the rate of tial starter dike is constructed at the upstream toe of seepage through and beneath the dam and ba,in area.

the altimate dam. The crest of the dam is raised by it is importan: ' hat seepage pressures be controlled so placing till materials in successise dikes located on that quick conditions and piping do not deselop Spe-the dow nstream side of the starter dike. The cen-cial design features such as impervious c o re s.

terline of the dam crest is shittu! downstream as the cutotts, impersious liners, a secondary collection dam is raised. liach subsequent stage of dike con-sy stem, etc. are needed to maintain the quality and struction is supported on the top of the downstream quantity of seepage f rom the retention system within slope of the presious sectio.t All of the embankment tolerable limits of w ater supply and pollution t ontrol ection lies ouside the boundaries of the sediment requirements tailings. Materials incorporated in subsequent stages Seepage analy ses-usually based on the steady of the embankments may consist c! the coarse mine flow of an incompresuble fluid through a porous w aste or borrow materials from nearby pit s.

medium-may use the graphical method of plotting Downstream construction permits controlled place-flow nets, electr ic analogs, model studies, or ment and compaction to achiese higher shear l 9 either finite-element or tinite-dif ference methods.

mathematical solutions by digital computer using strength. It also permits the incorporation of drainage tacilities to control the piezometric pressures within 142 257

.u i.3

the embankment ~l hus the dani can he designed and niethods to ensure the utely function of the taihng subseipiently tonuructed to whateser degree of com-dams, especially in seismically attis e arcat pctency may he required including resist ince to sennuc and bleiing shotkt t he tenterhne method is intermediate between the

4. INSl!ECTION AN D.\\l AINTI'N ANCl;,

pre s iou s t.m omstruction methoJs. T he trest of the embankment is maint.uned in apprintunately the same Di!!crent conditions can deselop throughout the horimntal position as the enihankment is raised to its whole actise hie of the retention sy uem and could final height. The dam is r.used by spreading and include unantimipoted scepage conditions and t hanges c ompacting success.s e lay ers of materials on the m material characteristics. Such thances can drasti-crest, on the upst ream s;ioulder, and on 'he cally thange the conditions goserning the stahihty of ihm nstre un slope. l he centerhne method permits the a dam f rom those prosideo f or in the original design dim nstream half of the taihng dam to be designed t herefore, a continuous program of inspection of the

.md c onstrut ted to c ons entionally acceptable en-retention sy stem is needed. beginning with the start emecemp standards how es er, cert.un portions of up-of construction. through the t.u!ing disposal. and con-stream slopes rest os er the slunes and are therclore tinuing af ter abandonment of the completed system.

s ulnerable to slope tailure and seisnue hquelacton.

.lhe Inain ohjeCttses oI slit h a program are to av lhese three construction methods lead to substan-tially diff erent embankment cross sections and pro-

a. W hether the dam and its f oundation are hchas-dute di!!crent embankment material charatteristics.

ing as anticipated in the design, s hether there are any Con seq ue n tly the embankment stahihty conditions unusual mos ements, settlements, c rac k s, crosions, are Jlletted. In the upstrealn and tenterhne methods sloaghs or leakages and w hether the w aste and bor-(1! ( tinstrut ti m. the stability <>f the ultinnite dam is row materials beiiig placed in the dam have the de pe n d e n t. to a large degree. on the shear strength t harat teristics awumed in the design; t har.u teristic s of raihngs deposited upstream of the d.un..I he shear strength is pos erned by the gradation

h. Whether the tailing pond lesels ar rising as an-ticipated and whether the rate of dam construction is and density of the solid s. the consistency of. the sillrrs, and the dist!!bution td the piire water pres-sutticiently rapid to keep the crest abose rismg pond; smed w ithm the deposit. When initially depmited, the taihngs base sery low shear strength The

c. Whether embankment drainage is adequate.

strength theoretically mt reases w ith time a s drainage w hether tae capacity of diseruon channels is and consolidation take plate under the weight of adequate to pass esperienced and anticipated runolls.

oscrly mg materials. How es er, because of the sery w hether embankment sod is becoming saturated by fine pradation of the taihngs and the random nature scepage. w hether piping or subsurface erosion is oc-of depositmn. laree s ariations ni permeabihty and curring in the taihne dam, and whether there is any pore w ater pressure cust within the t.nlings, and the unusual release o: radioactise materials.

strength inay not incicase adequately to ensure the stability of the final slope (Ret. 2M lt is neceway that mspection be putormed on o recular basis and that it include sisual inspection of the abutmentt A checklist similar to that used in 1)ow n stream c onstruction is the only method w ater retention dams may be used to help the inspec-w herein all embankment sections lie outside the tail-tor in performmg such a sisual inspection.

mg boundariet thereby permittine controlled place-Instrumentation needs to be installed to monitor dam Inent and compactum of till and incorporation of.

and basin perf.ormances at regularly scheduled inter-dialDJee t acilitie s.

I.hus f or a eis en heicht anu, a sals. lustruments comnitml) used include ple/timet-

'eisen 'dow nstre un till slope, a t uhng ' am con-d ers to measure hsdrmtatic and pore prewure lesels; structed using the dow nstream inelhod will hase a u eirs or tiumes v ;neasure seepage flow s w ells to higher tactor of safety than a tailing dam constructed permit momtorm of water qualits; and slope indi-bs cilher the upstream method or the centerhne meth J.

cators, inclin., _ ters, and settlement pomts to meas-

~

ure hori/ontal and sertical mos ements..I.he in-strumentatior should be simple, robust, rugged, reli-I!ccause the most important purpose of the raihng able, and easy to read. repair, and maintain. It is im-dam tructure is to tontain the radioactise waste ma.

portant that recorded data trom instrumentation and teruls and the perf ormance of hydraulically con-mspections be esaluated by competent personnel with structed d.uns and t.nling d,uns has been unsatisf ac-delecated authority to take prompt action if remedial tory t Nefs. b, k and 271 the dow nstream method treatment is needed to maint.un the safe operation of appears to be the best of the stage conuruction the retention sy stem.

142 258 m,

C. ItEGLI AI ORY IN WITION pool eles ation equis alent to the ascrape annual Ihe folhmine uiteria reflect the latest eeneral ap-proaches approsed by NRC Inf ormation related to the insestication, engineering design, proposed con-1 EIE

1. EM strustion, instrumentation, and perf ormance of the re-tention sy stem should be presented in accordance T he pmbable mnimum th od should be deter-m with the apphcable portion of Scuton 256 of Repu' mined in anordance with applitable portions o! Rep-latiir) ($ulde I.3),

'StandJtd I ornlat and ('ontent til ulat<4s (iuiJe 1.91

'I)esien liasis I'loi d s fo r N u -

\\

Saf ety Analy m Reports f or Nuclear Pow er Plantt clear I ower Plants.

If an appbcart w ishe s :o use new information that may be deseloped in the f uture or to use an alterna.

b. ~lhe static stability of the embankment should tne meMod NRC aill resiew the proposal and will be analy /ed using commonly aaepted detailed stabib approse its use, it is found acceptable ity methodt Appmpriate static soil and rock prop-erties estabbshed on tested representatis e samples mer anticipated in-situ and placement conditions

1. IMSIC I)l'. SIGN Cit lII:RI A should be used in the analy ses. Results of a manual chet k on computer stability analy sn results should be Stabihty of the retention system. meluding the presented to illustrate adopted design procedures and a

taihne dam, f oundation. and abutments, should be s ri t e. ri a.

ensured tindeI all conditions of construction and operation

c. Corn entional pseudostatic analy sis may be wn-sidered aacptable if the seisuuc cociticient appro-b.

IhC inagnitude tif liital and dillerCntlJI sC! tie-priately reflects the geologic anJ seismoloeic condi-ment should be withm tolerable lim:ts that w ill not tions of the site anJ it the materials are not subject to reNult in harmf ul crackmu and dam m.stabihis.

sienificant low of streneth under dy namic loads.

c. bCCpJge through the embankment, foundation Liquefaction potential anJ the dy namic stability of ab irm Cnts, and basin area should be Ctmirtilled to the tailing dam and loufklJtitm shtiuld be awessed present excessise uplitt pressures, piping, sloughine, using approprute state-of-the-art methods. lhe extent and crosion et materials by lo w into cras ks. joints, of the required dy nanuc ana!>ses will be determined and cas ities. ~Ihe quality and quantity of seepage in accordance w ith Reference 24. Appropriate j shouhl be limited to the extent that the concentration dy namic materi:d propert., established on represen-of radioAtise materuls and other toxic materials at the ratise materiais throuch adequate tield and laboratory site boundary n within the limits specified in appli.

testing should be used in the analy ses.

cable I ederal and State regulations.

ggy g

g

d. I reeboard should be sutlicient at all times to stability analy ses and corresponding minimum fac-pres ent osertopping by wind-generated w ases and tors of saf ety are:

should include an allowance for settlement of the ItiundJtion and dam. Adequate sliipe priitectiim Slinirn u m Shear should be prosided for the embankment against wind 1.nading (.o n dih.on I at tor of $aftty Strength and w ater erosion. w eathering, and ice damace.

I na ei miewn i3 11 and to

c. liither the surcharge capacity of the retention Parnai r~1 w nh wuds ss stem should be suf ficient to store runof fs oser its

'" P" A i'

Cl' o ' UD sersice hfe or there should be an emereeney div

""""'""IW " "h *3d>

'cerar i>

ci. orCD charge capacits capable of passine the probable 1 arthquake (in wmbinatwn u nh mnimum flood. 'lhe emergency dacharge capacity

,g c,g g,

y may be obtained by constructing a spillway or by other means. The surcharge capacity should be adequate to store a pronable maximum tiood series' preseded or followed by a INycar flood, as.umine,

e The rate and nmnitude of settlement should be

~ ~ - -

estimated on the basis of appropriale laboratory test results.

' i he Nus lear Reg ulatory Conmu ss on announs ed m t he /,.!, ra!

L er m i of rane ( 19 A 141 lR M 4115 Ms inh et to prepare a

[. Scepace anal)Nes may be based on a graphical genem enurennaul impas t sucment icI lsi on uramum null-method. model studiew or mathematical solutions ing operahons M a n a ge rn e n t prasthes fer us anium mill talhny s m.ny be sub;ct t to res nien in au erdans - w nh the c onsluso ns of that statement and any relatcJ rule making

' Probable ma umum flooJ sene s as useJ herem : ompnss two floodv t he Pr Ai'le M.iu ma m f io >J a nd t he flood equn alent to

'I ^ tor of sakty n tid pseuJatath stabilny analy sn in adJun n.

about 4W; et the PMF and about 4 to de s poor to the owur-IN"JI^ U"n and ewwne dciermanon shoulJ be a su ued rens e of the m.u n th >od

'l\\ shear stregth for sase analyzed w ohout caohpake 3.}].7

3. CONS I RITTION NIE'lilOI)S P'd"rmed on a regular basis and supplemented by adequae instrumentation are acceptable

'l he saf ety Cofis Cfll!nnJ! as cCptablC CngmJCring practh Cs inspection guide lInes I Ret. l2) lor carth danw set a

ilt e i)h s t r ut litin tiintrill tier w 8el retelitiiin dams tiutti by ths ('iups iit lingineers in respimse ti, tiie (e g.

tilf) trills iin ltiufldat tilfl preparathin, suitabillt)

Natiiinal 1)ani haf ety At t shi uld be tised tii deseli p a i

i a tt nl.iterials, priipCr place!nenl. flC!d 111olsture. alh!

detailed chet klist tiir perliiriiiilig field irispet' i'n s. In d efi sit ) ) shiluid be tised ! if 1111ll tJilIng d;tfus. W here tiJ ditiiin, r ad iiiinet rie a rid u at e r q tialit y rseys a talling dJnl is ra! sed in stJges, the diiw nstrearn ciin-shinild be tricltiJed in the pringrain strtit tliin illet }hid is pretef red. Prtisishin slhulld be

b. Instrunlentation sllould be illstall J in the dam made to linut the cont entration of radioat tiw and air it s lolllidation to illlinilor t hJnges t hat nught he it!Ilet tilsiC Ill a t e rl a l % releJNett t rillin scepJye and tr!!ical to danl stabillt) tir scepage _ Lindit hlih. (.ICn-wind w ater crosion to within the innits spet itied in

,1 er.dly. instruments should be installed to nwasure

-). Mi ( I'N I, art l dt). Jfld applicable It) (. l' Is, },.i r t pic/ometra les els scepage flow s. w ater quality. and State regulatli)fis enlbanknk nt mos ements l he estent to whnh sut h b Ihe lip st f e a n) a nd Ce nterllile citu st ruction InstIllnle!llJtiof slioulJ be inst.illed will be es aluatcJ lliclhieds w ill be acceptable iinly il estensise espli ra-i on a case by t ase basis tions.nd testing rescal the estent and char.hteristics Rewlts of inspet tii n anJ iristrtinientatiori prii-ist depiisited tailings til hJs c adcquate strength under i

e.

static and dy n ilinc loadmg tenditions for the stability gr.nns should be es aluated by competent and experi-

.ind slippt'It til the added Inaterials enced crigineers w hii has e delegated autin rity tii take prompt ettectne actions w hen necessary inspet tien

4. INSPECIION ANI) NI AINTENANCE and esaluation reports should be kept at the site and A act.uled v stematic inspetti in and mainte-a program should be estabhshed to delett and d. 'I h e in spet tion and maintenance program narh iep ur d.nnage that a ght tend to lessen tht integrity should start at ti e beginnmg of construction and con-iit the Terentii'n sy steln (3elierall). s lNual inspectitlus tillue at ICast thlinigh the i peratiiin.

i O

/ 7

') n/

3.1 1 - h, f

Lv m

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R. Dobre> and L Als arer.

Seisnne f ailures of

15. T.

W. Lambe and R.

V.

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Niet hanh s and I oundations 1)iv. Nos 1967.

1969 16

'l ngmecong and Design Stabiiny of Earth and 2.W A Wahler and D. P Schlick. ' Aline Ref use Rock-Fill Dams.

E NI 1110-2-1902, l' S. Army impoundments in the l'.S.

Proteedmgs of the in.

ternational Congress on lairpe Dams N1exico City.

C"rps of Engineers 1470.

1976

!7 J. Eow e. Ill. 'Stabihty Analy sis of I mbank-t National Dam Saf ets Act. Public l.aw 42-367.

Inents ASUl: Journal of the Soil N1echanics and Au; X.1972 Foundations IM.. July 1967.

~

4 S. R. Ilmrow man and P T. Ilrooks. ' Radium IS. R. V. W lutman and W. A. Itailey.

'l'se of Remos al f rom l'ranium Ores and N1ill Tailings.

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ASCI ILS Itureau of N1ines, l'.S Dept. of Intenor.1975.

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Juh 1967 i

'l'se of l'ranium N1ill 'I.nlings f or Constius tion Purposes.

Hearings before the Subcomnuttee on

19. R. I Goodman and 11.11. Seed.

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1:ncrgy of the lLS. Congress. Os t 2X and 29.1971.

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20. II. IL Seed et al.

The Shdes in the San i er-ing Sy mposium. 'l ueson. An/ona. Nos.1972.

nando Dam During the I arthquake of February 9 1971.

ASCE Journal of the Geotemhmcal Eneineer-

7. F Gruner. ' Classification of Rnk.

Proceed mp s meDn.

~

of the Internanonal Congress on I.arge Dams. N1a-Juh 19 E dnd.1973. Vol 1.

21

11. 11. Seed. ' Slope Stabihty During i arth-quakes.

ASCE Journal of the Soil N1echames and N. A. (). Itabb and T. W. N1ennel. Catalog of Dam g.oundations Dn.. July 19R Di sa st e rs. F.u lu re s and Acudents, llureau of Re-9 clamation, l' S. Dept. of Interior. lohs 22 N. N1 New in ar k. 'Ettects of 1:arthquak s on Dams and Embankments.

Geotechnique. June 9.

A. (.asagrande. ' Notes on Design at Earth g yg '

Dam s.

Contribunons to Soil N1echames. Ilost on Soact) of Unil Engmeers. 1950.

2 3. f l.11. Seed et al.

Dy namic Analy sis of the ShJe in the i ower San Fernando Dam Durme the 10.

. Design of Smail Dams, ilureau of Reclama~

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Engineering and Design-Standard Project 24.

Earthquake Design and An.ilysn for Corps of I-lood Determinations Co rps of Engineers. EN1 Engineer Dams.

ER 1110 2 1506 l'.S. Army l 110 2-1411. l'.S Army Corps of Engineers 1965.

Corps of t uncers. April 1977.

12.

Recommended Guidehnes f or Satdy lospecuon 25.

Summary Report Phase i Study ot inactae N1til o! Dams.

lLS. Army Corps o. Engineers. Dert "I

Sites and T.nhne Pdes.

Unnumbered ERDA EPA the Army.1976 Report. Oct. 1974.

13.

1 arth and Rock-Fill Dams -- General Design 26.

N1onthello Niill Tailings I rosn n Comrol Proj-and Construction Consideranons. E N1 1110? 2300 ect. N1onticello. Cuh. Suppiemental Report, l'.S. Army Corps of Engineers. 1971 CS AEC Apol 1966 14 J i. Sherard et al.

' Earth and Earth-Rock 27.

Lessons f rom Dam incidents US A.

ASCE Dams John Wiley & Sons. Inc New i ork. !963.

l'SCol D Repert.1973.

Illlll.IOGRAPIIY C. D. Kealy and R. I Soderberg. Design of Dams

'Tentatise Design Guide ti r N1me Waste i mbank-l for N!ill Tailings U.S. Ilureau of.N1ines Inf. Cire.

ments in Car,ada.

Dept of Energy. N1ines and Re-8410. 1969 sources.N! arch 1972.

'Engincenng and Design N1anual-Coal Ref use Dh-

.NIanagement of Wastes f rom the.N1imng and N!il-posal Facilities.

U.S. Dept of Intenor. NIES A.

line of l'ranium and Thonum Ores.

I AEA 1976 l Prepared by D' Appolonia Consulting Engineers. Inc.

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142 262