A)

COLLOID NATURAL ANALOG STUDIES

AT

CIGAR LAKE

By

Peter Vilks, Jan Cramerand Don Bachinski

AECL ReseachWbiteshell Laboratories

Pinawa, Manitoba

YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECTCOLLOID WORKSHOP

1993 MAY 03 - 05

K\1

. _ _ . _ = _ .

9311010116 931021WPDR WASTE.WM-1 I PDR 1)1

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PARTCLE SIZE CLASSIFICATION

Diameter (m)

10-9

10I

104IT-7

10I I

o t410 0 12

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Molecules'rnr __-.

£ imC

Vol

mm

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WATER FILTRATION SCHEME

DissolvedSpecies(c I am)

composition

Enriched in Enriched inColloids Colloids

(1 - lo am) (10 - 450 nm)composition composition

size analysisSEM

Enriched InParticles

(> 450 am)compositionsize analysisSEM/EXXRD

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PARTICLE SIZE DISTRIBUTIONSANDSTONES

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SIZE CLASS (nm)

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- MICROTRAQC -- ULTRAFINE PARTICLE ANALYZER -

Progression: standard Date:09/16/92Sample ID 1: 67 GRAB 21 Above Residual:Sample ID 2: 92-9-16 7:45 1368 L Below Residual:

Time: 08:080.000.00

100

90

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80

70

60

50

40

30

20

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PARTICLE SIZE FROM COUNTINGBOREHOLE 67

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

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1000000

100000

10000

1000

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10.45 0.95 5.5 10.5 15.5 20.5 25.5 30

PARTICLE SIZE (MICRONS)

C mg/L - countslmL

PARTICLE SURFACE AREA SIZE DISTRIBUTIONBOREHOLE 67

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PARTICLE SIZE (MICRONS)

0 SURFACE AREA - counts/mL

PARTICLE SIZE DISTRIBUTIONBOREHOLE 67

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PARTICLE SIZE (MICRONS)

F GRAVIMETRIC E UPA 0 COUNTING

PIEZOMETER 139_2 20 1 susp. particlesC -

E 15 ~~~~~~~~~oi~~~~~L ~~ 2.02L 2/

O~~~~~ S

AO 10 _

m as 1.0LU

0-2

cm

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SMPLE PFEOD

bUtEHOLE 671000000

100000I

r.

F~

10000

1000

100

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1

1000000

100000

10000

1000

100

8--a. . . . . . � I . . . . .

0.45 0.65 0.85 15 3.5 S 7.5 9. 115 13.5 155 175 195PARTICLE SIZE

. GRAB 22 + GRAB 23 . GRAB 24

- GRAB 25 + GRAB 26 A GRAB 1

BOREHOLE 91.05

-I

g.J

Up

10

I I I I . I I I I I I I I I I I I I I I I

0.45 0.6S 0.85 15 3.5 55 7.5 9.S 11.5 13.5 15. 17.5 19PARTICLE SIZE (MICRONS)

-s- 48 L +0- 176LA RESTART PUMPING 190 L - 5S04 L

- 28 -

TABLE 3

AVERAGE PARTICLE CONCENTRATIONS IN CIGAR LAKE GROUNDVATERS (1986-1991)

Suspended SampledHole Particles Colloids Zone Depth Comment

(mg/L) (mg/L) (u)

75 0.63 ± 0.14 0.83 ± 0.26 154-159 upper sandstone71 1.76 ± 0.42 0.73 * 0.16 243-245 lover sandstone80 1.42 0.77 203-205 lover sandstone67 1.90 ± 0.21 1.33 ± 0.30 346-348 altered sandstone81 9.20 ± 2.48 1.77 * 0.63 438 altered sandstone *

211 1.89 ± 0.49 0.81 ± 0.17 416-418 altered sandstone91 4.92 ± 1.48 0.60 ± 0.09 407 clay zone **

134 0.61 0.94 415-417 clay zone197 0.64 ± 0.13 0.72 i 0.19 416421 ore/clay contact79 2.23 ± 0.67 0.78 * 0.15 432 ore

198 2.86 ± 0.98 1.52 ± 0.29 424-426 ore220 1.87 ± 0.41 1.44 ± 0.38 433-439 ore128 0.74 2.21 463-465 basement137 0.81 0.03 473-475 basement199 106 ± 2.3 7.78 ± 4.14 446-452 altered basement139 1.73 ± 0.60 0.65 ± 0.16 437 inflow south, ***219 0.83 ± 0.15 0.95 ± 0.15 414-426 outflow north ****83 1.27 ± 0.41 1.11 ± 0.36 18-477 artesian (uncased)

122 1.00 ± 0.19 1.37 ± 0.35 0-200 artesian (uncased)P3.12 1.75 ± 0.08 0.91 ± 0.24 4-7 overburdenP3.8 18.1 ± 1.4 .13.0 i 4.9 10-22 overburdenP3.7 20.5 ± 3.8 10.3 ± 2.7 10-23 overburden

* Located just above the unconformity, near the clay zone. Fromthe core log, the piezometer Is set in altered sandstone, near afracture. I-

** Based on hydrologic observationi,-this piezometer appears to beset near a major fracture zone.

*** Located just above the unconformity.**** Located just above the unconformity, beyond the quartz cap.

The error values are given for boreholes for which more than onesample vas taken, and are given by the standard deviation dividedby the square root of the number of data points.

PIEZOMETER 139INFLOW FROM SOUTH ABOVE UNCOMFORMITY

I

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Is :

4,

as:

0

OXIDE a°

PlEZOUETER 7rUPPER SANDSTONE

la

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PIEZOUETER 21tOUTFLOW NORTH ABOVE UNCONFORMITY

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PIEZOMETER 57ALTERED SANDSTONE

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PIEZOMETER 17,.. CLAYIORE CONTACT

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PIEZOMETER 70ORE

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lTO10nm *1lOTO45Onm ,4SOnm

S4

c

40a

DISSOLVED AND PARTICULATE URANIUM

_ PARTICULATE03 DISSOLVED

10.00

0.01 i,,, _ _ + a o ,, , c 3

DISSOLVED AND PARTICULATE RADIUM

-J

ma-

C4m~

10.000

1.0000

0.1000

0.0100

0.0010

0.0001

DISSOLVED AND PARTICULATE THORIUMI.- .

-J

0

0.7

0.6

0.5

0.4

0.3

0.2

0.1

a

SS CLAY ORE BASE. ARTESIAN

SAMPLE

URAN-UM AND RADIUMARE SORBED FROM GROUNDWATER

- ( 23U/238U )pankcuhate = 1.99 ± 036

(2UP/23SU )di=oWed = 1.93 + 0.15

(2UI/238U )ro = 0.8 to 1.0

2. ( 2 26Ra12 )panT )d ei 4 100

(2 26 R 2 30 Th )o2a < 2.5

IF IT IS ASSUMED THLAT ALL 'le

230Th ON PARTICLES HAS INGROWN

FROM 2U, THEN THE OLDEST AGE

OF ANY PARTICLE MAY BE 8000 a

SUMMARY OF FIELD DERIVED DISTRIBUTIONCOEFFCIENTS (Rd)

Cigar Lake Rd (mdg)

uranium 2 z 103 to 2 x 107thorium 3 x 103 to 9 x 10 5

radium 2 X 103 t o I s 106

WRA Rd (ML g)

uranium 4 s 103 to 2 x 10thorium 3 x 104 to 7 x 10Sradium 3 s 103 to 3 x 10

The wide range In Rd values in groundwatersfrom agiven formation suggests that Us Thand Ra associated with particlesi mn t be,.---In equilibrium bndwaer_ .1

.lm water.~-.

9--~~~~~~~~~~~

PA . : w

. s

Average a 0Ur a A I vr**A Conven ,,of

&roundMailer Pr. fe/les (,VI

L.otv, r

Ump 0, c $

.A. ! ft e cGSd

S. S. IV3 dp"14.

SS. 4 .

S' S I0 +

A le, t va A Mu-VI

s! /.Oer S,. )

if. I W-

Ow;l ! 'W'

am o- -- t ,@ 'f2

*~~~~~~~~~~~~ -. ,.A

I. ,

C /iV. .*. _ 7

, .- ..

: WI

c 1h7 /ore. --covni&.-C l#l'pf

Ore

,-' ,, CONCLUSIONS

- F RADIOCOLLOD N IS REVERSIBLE,THE NATURAL COLLOlD CONCENTRATIONS ATCIGAR LAKE WOULD RAVE A MINIMUM IMPACI' ONRn TRANSPORT

- HOW1VR S41 N Ol' SOME Rn IS NOTREVESIBR IT IS NECESSARY TOUNDERSTAND FARCLE KMIGRATION

PARTICLE TRANSPORT FROM THE ORE AND CLAYTO THE SURROUNDING SANDSTONE HAS BEEN.NEGLIGIBLE

)

l~rt lritl:i

MICROBIAL MOBILITY ID METAL UPTAKE PHENOMENA

J.H. Wolfram, INE.L.Representative to MSU

,. J.W. C t4tn, IVSU - ERC

rrsentation for the Colloid Conference

May 8-10, 1993 in Santa Fe, New Mexico* sar i ,,. r!; '!, 1xtj.

K>

i6:

4 Al&�M kq.IdJWVS-i --

ft - -

Figure 1. Microbial metabolism

A wide diversity of metabolic capabilities exists between species ofmicroorganisms. This figure also shows some of the extreme environ-mental conditions in which microorganisms can survive.

K)

Figure 2. Microbial capacity to leach metals from ores

This figure shows the metal content of the effluent stream from abiomining'operation. Specific species of microorganisms are usedcommercially to leach copper and uranium from ore deposits. Themajority of the solubilized metal content of this effluent is a resultof microbial metabolic activity on sulphide ore.

,

KJ

Figure 3. Biosorptions capacity of a microbial species

Microorganisms can also accumulate metal ions many fold above the liquidgradient in which they live. Some organisms have been shown to accumu-late uranium and other radionuclide Isotopes of metall-ic elements. Themetals then migrate with the organism.

''.i dl if Y * '..

Figure 4. Hetallothioneins

The biomolecules involved in biosorption are either polysaccharides orproteins. Hetallothionein proteins are unique in this regard and eachpeptide can bind 7-10 atoms of a variety of transition metals. Poly-saccharide molecules Have been shown to accumulate actinides.

. . A� .. . :11 . IL I . :,. . I -, , ". .,. - .. . ... %.. .. -.. . .. .. .:.. M --- .". . . -.. 4 -

Itie,

g .

I

Figure 5. Petri plate containing colonies oforganisms isolated from vadose zones 65 feetbelow the surface.

Similiar isolations have been seen from sampleshundreds of feet below the surface. Thisdemonstrates the subsurface is not sterile asonce thought.

K)

Idl. . 1' , . '"

Figure 6. Laboratory demonstration

The petroleum industry in their attempt to use secondary recoverymethods needed ways to plug thief zones and channels. Berea sandstonehas good porousity but traps and holds large quanities-of crude oil.

Figure 7. Lab' demonsttation (;ot;DWell nourished organisms plugged areas close to the well casing.Pressurization from the water injection system would overcome theshallow plugs and very little oil recovery would result.

K)

Figure 8. Lab demonstration (Cont.)

By starving organisms and forming ultramicro bacteria (UMB), theorganisms could be made to move great distances. Adding nutrientswould then allow the organisms to grow, multiply and execrete exopoly-meric substances which forms a plug in the channels sufficient toprevent flow.

,-, !f �,.. 4�i.r� -,; -.): IM *Rhj .. :.11 , . . . . . . .: 1 , .9I 0. VA�, --i

xU---

Figure 9. A sem photo of berea sandstone

Side A, berea sandstone without any microorganisms attached.Side BP crushed berea sandstone with a covering of microorganisms.The covering is extensive and completely covering the poresbetween the particles.

v)

Figure 10. Lab'r :6ry column containing glass beads

Glass beads we~rUsed to pack a column. The pore diameters averaged 26micron. The average diameter of a microorganism is 1 micron. Expecta-

tion was that mictqbes would quickly move through the pore-spaces andexist the column.

K)j

Figure 11. Subsequent time interval following Figure 10

Sequence of events on the glass beads shortly after the organisms wereintroduced to the column cells began to stick and form a biofilm on thesurfaces of the beads.

Figure 12. Subsequent time interval following Figure 11

The biofilm continued to develop covering the surfaces of the beads andspanning the pore spaces.

I,.)

Figure 13. Final SEH picture of the well developed biofilm

The actively growing cells, although small in size, on contact with asurface, demonstrate their ability to adhere and form an extensive bio-film at least on the initial surfaces. This prevents the movement oforganisms extensively through the matrix.

K)11 v)

a I

*.

I I

* *' .d

.

0~~~

. T

. ,. If

Figure 14. Microbial presence in ocean waters

Previous research has shown a vigorous microbial population exists inshallow waters both as planktonic (free) and sessile (attached) cells.However, at great depths, no cells could be found using microscopictechniques. If nutrients were supplied, bacterial growth would beobserved. This was an Initial observation that bacteria when starveddid not die but shrunk in size from 1.0 micron to 0.3 micron. Thissize is below the resolving power of the light microscope and thereforethe UMBs went undetected.

.I -i: le. ..j: ? .. ;. .. I - .

-

I~~ - ,

Figure 15. Nourished cells under going sizereduction

This special series of slides shows the bacteriaunder starvation conditions becoming UM~s. Thetime sequence is about 24-48 hours.

. Figure 16. UMB'Techno.ogy

The petroleum industrkrusing UNBs can pump them down the well. Thesmall UHBs will not stick to surfaces and move through the pores ofthe berea sandstone. Pulsing nutrients after the UHBs have traveled,will cause a revival to a full size bacterium followed by populationincreases and adsorption to surfaces causing a deep plug.

U.S. PATENT #4.8 59

JANUARY 31, 1989

MICROBIAL PROCEXOR SELECTIVELY PLUGGING A

SUBTERRANEAN FOR ATION.

INVENTORS: J.W. cERTONFRANCtENE CUSACKF.A. MA^,CLEODT.J. CYR.

.ASSIGNtrE: ' AOS

gure 17. This technique was' pa;,:ted'2UMB technology receive4*i vj.' patent in 1989.The

I

K-

* * JYBIOB RR- -

RIER

Figure 18. Another ,sdbteranean UMB technique

An advancing plume of metal/radionuclide ions or hazardous organicscould be detained by placing a biobarrier ahead of it. This couldprevent the harmful affects of the plume contaminants in reaching theaccessible environment.

?

COLLOID DISTRIBUTIONAT THE KOONGARRA

URANIUM DEPOSIT

Tim Payne

Australian Nuclear Scienceand Technology Organisation

--..

Yucca Mountain Colloid Workshop(May 3-5,-1993)

OUTLINE OF PRESENTATION

1. KOONGARRA SITE DESCRIPTION

2. ALLIGATOR RIVERS ANALOGUEPROJECT (ARAP)

3. GEOCHEMISTRY OF KOONGARRA

4. COLLOIDS

- sampling p- elemental content- mineralogy- radionuclide transport

5. SIGNIFICANCE OF COLLOIDS

- - -

I.

.4

* i*�

* 'I-,

* *a'* �.

A

I

THE ALLIGATOR RIVERSANALOGUE PROJECT (ARAP)

An international project sponsored bythe OECD/NEA. Participants inagreement:

ANSTO (Australia)JAERI (Japan)PNC (Japan)SKI (Sweden)UKDoE (U.K.)USNRC (U.S.A)

Work was carried out by theseorganisations, together withuniversities, national researchinstitutions, and other laboratories.

A series of 16 reports covering theproject (1987-1993) will soon beavailable.

THE BASIS OF THE KOONGARRAANALOGUE

* uranium transport started whenthe weathering front (which ismoving downwards) intersected theorebody

* the rate of downward movementof the weathering front is estimatedto be 15 - 30m / million years

* groundwater moving in theweathered zone has re-distributeduranium in the system

* a uranium "dispersion fan"extending for 200 m has developedover about 1.5 million years

THE KOONGARRA ANALOGUE

Cmoundwaterri o -

I U 4 U-

We"thezed Zone

^ I I a*u! sne

am, GD

SV=!A=

~ W-Mu=

PRnOMORE Z=c

Fault

A. PRIOR TO WEATHERING OFPRIMARY ORE

Crcndvate _ D DSPZ P5O0 q CrFow It F rAN

=OTxm=rpszs

Fault

B. PRESENT DAY

c C C

S :mW

i

URANIUM MARRALOGY

Im Utomo WHI P" S.W*O

Iku wylp Pfft g"ofe

-- * G&ewndw-leffe

ALTERATION

:. 0 =

Um"q fleft\( NqyVM *tg e~ t I- g~w,,q am. " M et*)

le o m .h oe u.

x \ gn .mI"." no ,,,llA " d I tt

Pi eUm usfp 1o hmm.a~

talun . A pBn

.... ;.;. ::.:.. \-

GEOLOGY

vft"M. owlRose of .mwoovmg~

M~UI POTROU"ole

LOW"" PNQT!ROOi

C tE Ot st-"lt . 16me i

H1 *.e wh~~oot

E *,ptws-en - eobden

Mac3 Owettarnems doWe

m tw emn iB.. ash

6 is

eA61he.

1000-.

100:

10

a EC I

zano __

' o? Za

a

- in

1:

a

C~~~C

C

: t:A< C_ , _~~~~

-.3

ED I¶'3 00 :OSO ~ 300 MO 400 JR)3

i ID~~~~~~~Chsanoe a)

Uranium concentrations in groundwater (pGRlj as a function ofdistance from KD1

MAIN CHARACTERISTICS OFPH49 GROUNDWATER:

. pH near neutral• low conductivity• Mg2+ is the dominant cation. HC0 3 is the main anion. elevated concentrations of U and

U-series radionuclides• low levels of TOC;::. slightly oxidising with respect to

U(V)I/U(VI). Si is present at significant levels

GROUNDWATER CHEMISTRY ATKOONGARRA AND YUCCA MOUNTAIN

___ KOONGARRA YUCCApH 6.5 - 7.4 6.7 - 7.7

Eh (mV) +100 - +300 +000 - +400(mmol/L)

Mg2+ 1.09 0.07Ca2 + 0.10 0.29K+ 0.02 0.14

Na+ 0.06. 1.96Si 0.32 1.07

HCO3- 2.52 2.34Cl 0.10 0.18F 0.01 0.11

Po 43 - 0.003:_ -

S042 0.021 0.19(meq/L)

X Cations 2.48 2.82X Anions 2.63 2.82

The range of pH and Eh are for typical samples.Other data are for Koongarra PH49 andYucca J-13 (from LA-1088-MS [1984]).Charge balance only includes major ions.

"l Fr

*.W Ct.,, 200j All

10,

-0 to 5.00 6.00 7.00 8.00pH

* depth >16m a depth <16m* creek a rmin

pAh cfiagram for Koongarra groundwater showing the fieldoccupied by shalow groundwaters.

OBJECTIVES OF KOONGARRACOLLOID STUDY

1. To sample colloids (< 1.0 jim)and particles in groundwater

2. Physical and chemical'am racterisation '

3. Determine size distribution ofradionuclides (p"rticularly Uand Th)

4. Evaluate significance of colloidsin radionuclide transport

Can results from Koongarra help us'to evaluate whether colloids willsignificantly increase radionucliderelease to the accessibleenvironment at Yucca Mountain?'

*. Have colloids played a significantrole at Koongarra;?

* To what extent are results- fromKoongarra transferable to YuccaMountain?

* Is Koongarra a worst casescenario?

MAJOR SAMPLING PROBLEMS

1. TRANSFORMATIONS OFSAMPLES

Strategy adopted:* In-field separation of colloids - no

time elapsed prior to-ultrafiltrationstep

* Closed system ultrafiltration withoxygen free atmosphere(N 2 / COO

* samples sealed from atmosphereuntil analysis

2. ACCURATE PARTICLE SIZECUT-OFF OF FILTERS

Strategy adopted:* selected Nuclepore filters with

well-defined pore size of 1.0 gmas upper size limit of colloids

* electron microscope examinationof filters subsequent to samplecollection

Hollow fibre ultrafiltration sytem

(10000 M.W.5pLm and

ultrafilter membrane1.0[tm pre-filters)

(1= mm

a"al

a"u

i:

Stirred cell ultrafiltration system

NITROGEN ATMOSPHERE BOX

C c C

!

JIP4 l V,

r -~~~~r

T v -;- S

1;@- '4.w e

tifBo; - . >:

po:.-@ ** - ~ * h.*

.

.1.I

I

01ol 0 - .Qw. 'f -;A.e. - ;W�

: via . '-%0-000 II.-k :L� -f

Iu V-

.1 vl

(

Ij , . tr

PARTITIONING OF CATIONS. IN IJ-FILTERED GROUNDWATER BETWEENCOLLOID CONCENTRATE (CC) LILTRAFILTRATE (UF) AND ULTRAFILTER

BXAC1FLUSH (BF)(Hollow Fibre Ulttfitltration Experiments)

'S;- -:n"

Hole Fraclon K Na Mg Ca Al Fe Mn Si

K02 UF (mg/I) 0.65 1.69 15.5 0.92 c0.02 1.14 0.037 12.5CC (mg" 0.63 1.63 %ti 0.70 0.02 1.06 0.027 9.8BF* - . (O.1o) 0.8% .

PH55 UF (mg/)l 1.07 , ,.58 17.1 1.28 <0.02 0.77 0.067 12.5CC (mgL) 1.11 , '1.62 18.2 1.38 0.02 0.80 0.070 12.6BF* , . . (0.05%) 0.5% .

PH14a UF (mgIL) 0.71 1.49 21.7 2.29 0.04 0.43 0.36 9.2CC (mg/I 0.74 1.44 22.2 2.38 <0.02 0.46 0.37 9.0BF* - . _ (0.15%) 1.4%

PH14b UF (mg/L) 0.65 1.36 19.8 1.50 0.02 0.14 0.20 9.5CC (mg/) 0.69 1.37 18.2 1.43 <0.02 0.13 0.17 9.0BF* . . (0.2%) 1.1% .

PH49 UF (mg9) 0.58 1.12 24 1.60 0.02 0.40 0.13 8.3CC (mg/I) 0.60 1.09 23 1.60 <0.02 0.46 0.13 8.0OF* - - - (0.4%) 1.1%O

C('

* Percentage of total found in ultrafilter backflush. In cases not assigned a numeric value,ultrafilter retention was below 0.03%. Data for Al in BF fraction are bracketed because theAl values were close to detection limits.

Figure 3.5.23. Uraniumconcentrate (bar = 0.2 um).

ok .*-....

particles (U(Fe)) from PH49 28-30 m colloid

Figure 3.5.19. Kaolinite-like particles (crystalline, Al, Si). a) PH96 colloidconcentrate (bar = 0.2 pm), b) PH49 < 28 m colloid concentrate (bar = 0.2 jlm).

iI_L I

I

i

Figure 3.5.20. Chlorite-like particle (Si, Al, Mg, (Fe)), PH49 28-30 m colloidconcentrate (bar = 0.5 gm).

tKaI

ask

9 B~~~~IKMe

i~~~j a KSK kw

c ' (~~~~~~~~~~~~~~~~c

FmTrxcJ CO ON L _ O

Ic rc lw : L aI C'oili c _ zl l

c C C

P"49 W P119WI m VA M2 PH;6 C9 M3 Ws PtJ96

k~Weathered zone

k kaoliniteokc . C chlorite

. # ~uh uranium50m u/s uranyl silicate

pb lead

DISTRIBUTION OF SOME COLLOIDS DETECTEDIN KOONGARRA GREOUNWATERS

C

PARTITIONING OF 238U AND "'Th IN I ,urn-FILTERED GROUNDWATER

(Hollow fibre ultrafiltration experiments)

C

Borehole Mu Th

UF (ppb) Colloid UF (mBq/L) Colloid

K132 0.079 1.8% <0.007PH55 0:40 2.5% 0.073 33%PH14(a)* 87'7' 1.4% 0.160 12%PH14(b)* 205 1.1% 0.062 27%PH49 178 1.4% 0.053 82%

* There were two colloid sampling experiments at PH14.

i M A d -Iw -

Ii~~~~~~~

.1

I

Comparison of U concentratidns and mineralabundances. Uranium concentrations (ppm) alongthe DDH 3 core are shown with a schematic repre-sentation of the relative abundances of chlorite,vermiculite, and kaolinite (and smeftt).

.

s. Huzakami, IL Isobe R.Edis,

Hiat Res Soc Symp Broc 212, 1991

i

C C

URANIUM ASSOCIATED WITH COLLOIDS

(Stirred Cell Experiments)

(

Hole Sampling Depth U. U. % of U on(m) ppb ppb Colloid

WI 23-25 m 0.24 61 0.4W4 13-15 m 2.6 470 0.5W4 23-25 m 1.0 300 0.3Ml 27-29 in 0.52 620 0.1PH49 18-20 m 0.60 110 0.5M2 42-44 m 0.12 46 0.3W5 23-25 m 0.21 3.0 6.5

U. - uranium on collolid.U. - uranium in ultrafiltrate.

If the b.f. includes adsorbedspecies then the calculatedcolloidal 238U and 230Th should beconsidered to be upper limits.

If this material is excluded from thecalculation, then:

colloidal 230Th is 5 - 35%colloidal 238U is 0.1 - 0.4%

Whilst these figures aresignificantly lower, the colloidal23 Th is significant and remainsgreater than is the case for 238U.

v

DISTRIBUTIONS OF 3U AND 23Th AMONGST COLLOIDS, PARTICLES (>1 tim)AND ULTRAFILTRATES

Ultrafiltrate Collold asas Percentage

Experiment Percentage of Total*of Total*

=au

PH14(a) 87.4 1.26-PH14(b) 70.2 0.76PH49 64.8 0.91

=0Th

PH14(a) 0.48 0.07PH14(b) 0.08 0.03PH49 0.007 0.032

l Tbe'total -includes ultrafirate and particles in allsize ranges,angs ......nWI

I

c

DISTRIBUTIONS OF 23U AND 2Th AMONGST COLLOIDS, PARTICLES (>1 lim)AND ULTRAFILTRATES

(Hollow Fibre Ultrafiltration Experiments)

C

Partilcles Particles Colloids Ultrafiltrate Ultraffitrale Colloid as>5 Jim 1-5 PM < Ji tm as Percentage

Experiment (mBq/L) (mBqCI4 (mBlq/) (mBw Percentage of Total. of Total*

PH14(a) 60.7 81.0 , 15.7 1090 87.4 1.26PH14(b) 547 507 27.5 2550 70.2 0.76PH49 722 452 31.0 2220. 64.8 0.91

"rh

PH14(a) 12.8 20.5 0.022 0.160 0.48 0.07PH14(b) 64.3 16.0 0.023 0.062 0.08 0.03PH49 445 348 0.250 0.053 0.007 0.032

* The total Includes ultrafiltrate and particles in all size ranges.

a) 238u

0.J

b) 230Th

CIj210

5Lm 1pn 10000 MW

filter pore size

unfifternd

50

40-

30 -

20 -

10

P.

I-- ..

ulftafitered

__~~~ / I

5Am 1p 100'M

fiter pore size

Effect of filtration on radionuclide levels in groundwater

Potrf"It MesS I. .JinjS

(Borekoltes l uarseort -6oJ7)

S s a 150 - 20oOnsLa

U

4 OOo0Mw

e 3 m h

A)

0

C-B

B)

01

0

C.)

5 2 2 Th1 64

2 3 8Th

a i Rn

72221.R22 a Ra

227t*. hi

, T.3h

,I-.. I Ii 'I

2hIs

| 2.1 |I

allSi-

tAn

. ,,_ .! _- U ________ -

4ltergy(MeV)

_ _

7

Thoriuma)b)

alpha-spectrum for PH14 samples retained by:1 pm Nuclepore filtercolloid filter

I.-

TEWORXL ALaPK& SPECTRUM

KOONGARRA CORE: SA;PE

iwTh

's V.Ii r Xt , X- -i .r t . .-K. ....~~~a

4

I

m -Th.A1 I

Lq..asTh

A_1 Thl

.- _ -.Aia

4I I_ U. *

-

5 '6

Energy (MNeV)

CONCLUSIONS

* Uranium migrates mostly asdissolved species

* Thorium and actinium are mostlyassociated with larger particles(> 1.0 gm)

* Only a small amount of colloidalmaterial is present

* Colloids reflect the mineralogy ofthe solid phase

* Colloids carry measurableamounts"d 6ThI 238U 227Ac, andFe

* In 1.0[im-filtered groundwater,5-82% of 230Th and 0.1-2.5% of231U are associated with colloids

* Colloidal transport is of greatestsignificance for Ac and Th

* Colloids are relatively unimportantin transporting radionuclides atKoongarra

Formation ana Physicc-chnemicafProperties of Radiocoaloids

David E. MorrisSpectroscopy and Biochemistry GroupLos Alamos National Laboratory

I-- .

Yucca Mountain SiteColloidMay 3

Santa Fe,

Characterization ProjectWorkshop.5, 1993

New Mexico

Operational Definition

* Radiocolloidsexclusively ofradionuclides

are composedhydrolyzed

-~ ~ .; ., -- V^

9.

* There is no sorbing substrateinvolved

RADIOCOLLOID FORMATION PROCESS

Hydrolysis:

M 4 + + 3H2 0 40 �-

mm4p- M(OH)3 + +3H+

Condensation:/OH

2+

.iH 2 02 M(OH)3+ -4 �--0-

Oligomerization: 4- ..

1sCOLLOIDS - n H 2 CI

Maii et at. Nuci. Tech. 84, 82 (1989)

Candidate RadionuclidesConsiderations:

1) Part of PA's inventory2) High charge/radius ratio for accessible

oxidation state3) Concentration in Inventory

I. Plutonium

II. Americium, Thorium,Protactinium

I I I . Uranium,Lead, Tin

Neptunium, Actinium,

IV. Radium, Nickel, Strontium

Philosophy forRadiocolloid Studies

Studies are comparable to otherradionuclide speciation studies

_ Howe _~dd t 3on h--~~~ - xe -

characterization a're d-* to assess tranfsport potential* to- understand and correlate

reactivity

I , -%, � -

S Oz. L I PICT I �- VA - ~~~~~~1-

I II \F-T hA C

I - I.71#rflQ

)"A oE ~tj C-6M E I -7 � e � -I - rz

I--.

Philosophy forRadiocolloid Studies

Chemical Properties

* Synthetic Conditions* Stoichiometry &

Molecular Structure* Trends in Reactivity

Physical Properties

* Particle Size* Particle Density* Bulk Particle Charge

FORMATION, CHARACTERIZATION, AND STABIITYOF PLUTONIUM(IV)-COLLOIDt

David E. Hobart, David E. Morris, and Phillip D. Palmer

Isotope and Nuclear Chemistry DivisionLos Alamos National Laboratory

Los Alamos, New Mexico 87545 USA

ABSTRACT

Several actinide elements are known to form colloids under environmental groundwaterconditions. It is imperative to study the physico-chemical properties of these colloids(particularly plutonium colloid) as pertains to high level nuclear waste isolation andstorage. In the event that a nuclear repository containing plutonium is breached by near-neutral pH groundwater, it is most likely that, as discussed in this report, the plutoniumwill form colloidal Pu(MV).

This report provides a thorough literature review (to June 1987) relevant to pertinentaspects of the chemistry and physics of Pu(IV)-colloid. In addition, the results of anumber of experimeta performed in our laboratories are presented which provide newdata to characerie further the physico-chemical properties of Pu(1V)-colloid. Thesenew experimental data include a detailed comparison of the electronic spectra (abSorptionand diffuse reflectance) of Pu(M1-colloid and numerous other Pu(MV) complexes. On thebasis of this spectral comparison, it is concluded that Pu(IV)-colloid is structurally verysimilar to finely divided crystulline PuO2 . -This is in agreement with conclusions drawnfrom other experimental rrnita Including X-ray and electron diffraction studies. Recentresults are also presented concerning the rqdox reactivity of Pu(IV)-colloid. It has beendetermined that the colloid can be reduced to aquated Pu(ffl) by either zinc amalgam orelectrochemically at a mercury electrode. The electrochemical reduction shows a strongpotential dependence with an abrupt increase in the rate of colloid reduction at - -1.0V v SCE. The colloid can also be oxidized electrochemically to PuOs+ at a platinuelectrode. In this cae, significant oxidation rates do not occur until - +1.4 V vs SCE.Finally, this report concludes with a brief summary of the proposed future direction of thePu(V)-coloid Investigation.

t Nevada Nuclear Waste Storage Investigation Interim Report No. R718

1

Some Pu(IV) ColloidFormation Reactions

* Dilution of acidic solutions of[Pu4+]aq[Ockenden and Welch J. Chem. Soc. 3350 (1956)]

* Precipitation of Pu(IV) hydrousoxide and peptization in diluteacid(CoeanZo et at. J. lnorg. Nuci. Chem. 35, 609 (1973)]

* Extraction of nitric acid fromPu(lV) solution with n-hexanol[Uoyd and Haire Radlochim. Acts 25, 139 (1978)1

* Auto-oxidation of Pu(IIl) stock indilute acid[Morris et al. YMIP Milestone Report M367]

K>

I

9 9 9

C

Drip tests done with spent fuel show surprising radionuclidedistribution patterns (compared to saturated tests) and alsoREE and actinide-bearing colloids.

(

DW Tests (of L) Saturaed Tests (oIL)

Filtered(50 nm)Unfiltered

Am-241Cm-244Cs-1 37pH

2E-44E-42E-44-6

4 T

I . ,1E-61E-6

Unfiltered

lE-10

2E-3. 8

0m

(a) Micrograph of agglomerated colloids from spentfuel leachate. The individual particles are around 50-100 nm in diameter and (b) SAED analysis suggestedthe phase was the uranium hydrate schoepite.

The compositional analysis: U, 0, Si, and REE

EELS was used to identify the REEs; La, Ce, Pr, Nd, and Sm In theschoepite colloid

bazan PEELSI JUVP..Un

Bank:rnllMemorg:Ia)b c d e I Y 2

cursor. 1020 Width: 0.48547 Counts: -17

2000,

Ce- M4,5

1hI I

-4 . ........

1500,Nd-M4,5

I'/non,

5001

La-M4,5

'L.L ..

Pr-M4,5

L I.. .....j Sm-M4,5

..

........ ..... .. . .. . .. .I. .

..... .................................................

nl L_ _ . .

_, . . __

y.... i.*5001 ....

rVr F, - r -

-_00o0................-- ---I..... - ------- 1-................ I-- --------.......... ............ ..... .. ...

900 900 1000 1190 1290 1BOB -goo -loon 1100 1 200 I

K>

As the waste form reacts, It strongly influences thedistribution of radionuclides to solution. It is possible toIdentify the colloidal species, the size distribution, and theradionuclide content.

* Primary colloids - form directly from glass and U02due to spallation of material from the glass, contain,concentration Pu/Am phases, remain suspended Insolution.

* Pseudocolloids - form as glass and spent fueldissolution products nucleate in solution (J-13 > DIW) -the distribution in solution depends on the ionicstrength of the leachate.

COLLOID FORMATION FROM SPENT FUEL DISSOLUTION

Walter J. GraySenior ScientistPacific Northwest Laboratory (PNL)Richland, Washington

.I

Yucca Mountain SiteColloid

Characterization ProjectWorkshop

May 3-5, 1993

Santa Fe, New Mexico

K)

INFORMATION SOURCES

* C. N. Wilson, Results from NNWSI Series 2 Bare Fuel Dissolution Tests,PNL-7169, 1990.

* C. N. Wilson, Results from NNWSI Series 3 Spent Fuel Dissolution Tests,PNL-7170, 1990.

MAJOR TEST DIFFERENCES

* Series 2 tests employed' fused silica vessels, 250C

* Series 3 tests employed stainless steel vessels, 25CC and 85°C

* Test results were similar at 25°C

* Generally lower releases and fewer colloids were observed at 850C

.FUSED SILICABASKET WITH BAIL

FIGURE 2.1. Series 2 Bare Fuel Test Configuration

2.2

Composition of J-1

Component

Ca

K

3 Well Water

Concentration (mg/L)

13

4.9

Mg

Na

2.0

44.

Si 30

Cl 6.7

F

NO3

so4I- .

f . .,. 2.3

9.0

19

126

1.8

HCO3

Organic Carbon

pH 8.4

SAMPLING SCHEDULE

* Periodically (every few weeks) collect water sample (10 to 30 mL)

* Filter and analyze

* Replenish water

* Approx. every 8 months Jroplace entire water volume and begin new cycle

K)l

239 + 240pU In Solution Samples

b0o2I 1,wCD

1000 60 100 160 200 0 50 100 160 200 0 60 100 160 200 0 50 100 150 200 0

Days60 100 150 200260

2807012.4

FIGURE32. Activities of 239+240Pu Measured in Solution Samples

K)

241Am In Solution Samples104 _ .

'aa

102

SO I 1 200 0 _________________ ~~~~~~~~~Cycle 6

0 60 t00 160 200 0 60 100 160 200 0 60 100 150 200 0 60 100 160 200 0 60 100 150 200 260Days aus0o0o2.2

IURE3.3. Activities of 241Am Measured in Solution Samples

2 "Cm In Solution Samples

mv 0.10g

Cycle 51 0-1 I I l _ __ _ __ _ _ _ _ l__ ___ l _ l0 60 100 160 200 0 60 100 150 200 0 60 100 150 200 0 60 100 150 200 0 50 100 150 200 250

Days ,,0,0,3,

FIGURE 3.4. Activities of 244Cm Measured in Solution Samples

K)

2371p In Solution Samples

2

1.8

1.6

1.4

1.2

w

co

r 1.0

0.8

0.6

0.4

0.2

0

INV-

0 60 100 160 200 0 60 100 160 200 0 60 100 160 200 0 60 100 160 200 0Days

60 100 150 200 260U8307012.9

FIGURE 3.5. Activities of 237Np Measured in Solution Samples

Annual Release Rates (including "colloids") at 250C in J-1 3 Wateras Fraction of: 1,000-Year Inventories

Actinide

U

Np

lop(Release Rate)

-8.6

% Colloids

-0

-0-8.8

Pu -9.0 20 to 60

Am -9.1 >90. T

I .,

Cm -8.0 >90

-

* Assumes water flow rate of 20 L/Yr per waste package containing 3140 kgof 33 MWd/kgM PWR fuel.

.-

a jV-DodA a 'I 4c0rrVJ5 G4rid-dior ,.S , Kkd in -kkr'''Dtn-c FAk , L

Organic Materials(continued) LiThe formation and stability depends on:

* Type of adsorbed ions

* Type of organic matter

* Ion concentration

* Organic concentration

. pH

* Ionic strength :

* Temperature

* Oxidation state

Note that characterization of immiscible organic liquids is lacking.

Are the consequences of Introduced Materials Significant?

CONSIDER:

* SCP DESIGN INCLUDES 560,000 m 3 of shotcrete in theemplacement drifts alone.

* ESF North Portal Facility estimated usage for FY 1993 includes:

- 6,o000,000 gal. water

- 250,000 gal. diesel fuel.1.

- 10,000 lbs. of rockbolt resin

- 180 ft.2 extruded polystyrene

- 50 yd.3 bentonite clay

- 250 gal. cable lubricant

v~~~~~~~~~~K

Organic MaterialsCOLLOID FORMATION:

* Degradation of greases, wood, other introduced organic matter

* Degradation of less soluble materials as a result of elevatedtemperature and chemical, microbial and/or radiolytic attack of:

- Plastics

- PVC

- Cellulose

- Rubber

- Polyethene

OxyhydroxidesSources are not only container materials, but also other introduced

materials such as stainless steel fixtures and rebar.Adsorption and transport effects are specific to the metal

and oxyhydroxide species.Potential aspects of introduced materials involvement.

* Fulvic acid and,Si concentration

* Elevated pH

* Reaction path

* Increasing adsorbate concentration

* Increasing ionic strengths

* S04 concentration

* Sorption of organic acids on goethite varies

wsqA4-U"

K)

Cementitious Materials 'Grouts, cements and shotcrete are sources ofcalcium silicate hydrate (CSH). colloidal gels:

* Known effects:

- Ash and silica fume can produce pseudocolloids at high pH

- Low concentrations of salts, aliphatic aromatics andsaccharides can influence transformation rate

* Unknowns:

- Cement additives (superplasticizers, curing compounds...)Presence of other ions

- Presence of organic material within or close to the cement- Aggregate and pozzolan chemistries- Effect of Eh gradient- Effect of pH gradient

Possible colloids derived from introduced materialsCOMPOSITION:

* Oxy(hydr)oxides

* Clays

* Organic particles

* Polysilicates

SIZE:

* Very small (< 10 rqm), eg. hydrated metal ions, small organicparticles, polyhydroxo-complexes, polysilicates, fulvic acids...

* Medium sized (10 -100 nm), eg. clays, metal-hydroxides

* Large (> 1pm), eg. inorganic and organic particles

K)

Examples of introduced materials that may affect adsorption and transport:

0

* Inorganic complexants (acid, batteries)

* Organic complexants and nutrients for microbes (e.g. alcohol,, antifreeze, bituminous materials, diesel fuel, diesel soot,I some gases, clothes, lubricants, plastic, wood...)

* Groundwater pH modifiers (acids, concrete, grout, lime, plaster...). ?

III

K>

Expected Gradients Caused by Intdduced Materials

* pH

* Ionic composition

* Eh

* C0 2 partial pressure,

* Temperature

* Radiation

* Bacterial activity!

i.e. The repository cannot be viewed as a homogeneous system

A_i" S

Waste Packages and the Cement IssueK)j

Lai_ .

4,A tO00E

_~~~~~~ 1Q0

_rj~~~~~~~~C

E

0 ~ ~ ~

, To far fieldand accessibleenvironment?

Time

Phase 2

10,000 yrsTime

Influences on formation, transport and stability ELCOLLOID CHARACTERISTICS:

* Physical size* Bulk charge* Density* Chemical reactivity* Chemical structure* Sorption potential

ENVIRONMENTAL CHARACTERISTICS: ,

* pH (cement)* Redox potential (cement, metal)* Ionic strength* Competing ions* Organic matter (peanut butter and jelly sandwiches)* Temperature* Microbial activity* Radiolysis

GRADIENTS in environmental chacteristics (space, time)

1 - 164 - j

* Colloid transport

* 'Adsorption mechanisms

* Formation of naturally occuring colloids

m 693- 1"w1

Goal of ioiaoid studies within theMan-made materials Task

Identify introduced material sources and their significancewith respect to:

* Colloid formation

* Adsorptive capacity modification

* Natural colloid enhancement

OBJECTIVE: Provide information for the development of policieswith regard to Introduced materials:

* Removal

* Minimized usage

* Special measures during emplacement and use

( ( CGoal of Man-made materials Task

DETERMINE THE CHEMICAL CONSEQUENCES OF INTRODUCEDMATERIALS IN THE POST-EMPLACEMENT ENVIRONMENTExamples

* WATER (drilling fluids, dust control, emplacement of cement)

* Insoluble metals (stainless steel): measurement devices,electrical accessories...

* Insoluble organic solids (neoprene, plastic): packer, rubber...

* Soluble inorganic solids (LiBr, LiCI, NaBr): tracers

* Inorganic liquid (water with tracers)

* Miscible organic liquids (ethylene-glycol): antifreeze,fluorescein dye.....

* Immiscible organic liquids (petroleum based oils): brake fluids,lubricants, oils, paints, grease, fuels...

* Organic gases: H 2, N 2, 02, CO, C02, C 2H 2

S

K)j

Other Introduced Materials:Considerations for Colloid Formation

M.a

I .

Annemarie MelkeTask Leader, Man-made Materials

Lawrence Livennore National Laboratory

May 3, 1993

_ i ~

K>

)IO *d hare I A & '4 - o7ma wonecessar 1 A b&umass 5

7eV Y'Ad AV ? I/Ai 0Ma7 looowo4d /? S

~~~~~~2.~~~~~~~~~1-1- %.-//

;.

* 7ho coors romaln sr>;n00r

uneons6 fAricv ?or

�*e.rd unkwo "Oovs*he 16*1 P