ORNL-TM-2677 by Jon Morrow

ORNL- TM-2677

Contract NO. W-74-05-en%-26

CI€ENICAL TECHnrOLOGY D D I S I O N

MANAGEMEUT OF NOBLE- GAS F I S S I O N - PRODUCT WASTES FROM REPROCESSING SPENT FUELS J 0. Blomeke J, J. PeronaX

Consultant, University of Tennessee

OAK RIDGE NATIONAL W O R A T O R Y

Oak Ridge, Tennessee operated by UNJOi\J CARBIDE CORPORATION for the U.S ATONIC EXERGY C O M ~ I S S L O N

3 4456 0513220 0

ABSTRACT Ln a n expacdirig n u c l e a r power economy, i t may become d e s i r able t o remove noble-gas f h s i o n products fro111s p e n t - f u e l processing p l a n t of-i'-gai;es Technology i s presently available f'or removal of krypton arid xeriori, and a f t e r t h e y have been separabed, it is proposed that, t h e krypton b e compl-essed En standard gas cyiindercs ( e i t h e r rutxeti w i t h xenon, or a f t w h a v i n g been s e p a r a t e d from i t ) : and shipped 'to a sal%-mine r e p o s i t o r y I'or permanent s t o r a g e .

A plant r e p r o c e s s i n g ~3810t c r i s l y e a r OL' r u e ? would produce o n l y 28 5 0 - l i t e r gas cylinders pe yeTr ut krypton, each cfmt a i n i n g a b o d d m i l L i m curies ol' '5Kr and generating about Bxu oi h e a t p e r hour. If t h e krypt,on and xenon were not s e p a r a t e d from each other, 160 cy1 d e r e l y e a r would !)e produced, each contairilrig lf%l,OCO c u r i e s of and g e n e r a t i n g h e a t a t h rate of l0OC I3tu./hr.

D i e p r e s s u r i z e d gas cyliiders could be s t o r e d i;empo-r.nriLy at tfie p l a n t i n w a t e r - f t l i e d c a n a l s , and t h e n shippcd t o a s a l t mine i n s p e c i a l l y - d e s i g n e d casks cont;aining fr(7111 oiie t o f i v e c y l i n d e r s each. Rr, t h e mine, t h e c y l i n d e r s could be sT;ored above the L'loor in moms l a t e r s e a l e d t o i s o l a t c them from the remairlder of the mine. Under t h e s e conditions, the c a r b o n - s t e e l c y l i n d e r s should l a s t many decadcs, and t h e mine space r e q u i r e d woiild be o n l y about 1 - t o - 2 p e r c e n t o f t h a t r e q u i r e d for s t o r a g e of soli-rlified high-l e v e l wastes

The cost, o f noble-gas management by- this rneLhod, exclusive of t h e cost 01' s e p a r a t i n g the p x c s f ~ o mthe p l a r i t ' s process off-gas, i s est'*rcatoed to range from $130,090 T O &22O,UOG per year ' a i s r c r r - e s p n d s t o $J.C)(JO 3 to o .OGO j> mill;/kwi.ir of From the s t a n d elec1,rleitjr origioaily prod~ccd i ' u . 0 ~t h e f'uel point of' t h e p r o j w w d s c a i e of' a p e r a t ? m s , t*rieir estimated cos t : ~ ,and comiderat.Lons 01' safety, t h e proposed method appears r e a s o n a b l e and manageable over t h e next sever31 tlec-ddes

I n t h e p r o c e s s i n g of spent f u e l s , t h e noble-gas . f i s s i o n prod-iicts a r e

sepai-ated from 'die f u e l during t h e cladd jhg- removal and. core-di.ss o l u t i.on steps,

A t p o s t - i r r a d . i a t i n n &cay

8?Kr c o n t r i b u t e s @-eater t h a n

times of 1-50 days and I-onger, lO08-y

99.5% of

t h e total. a c t i v i t y present, i n

t h e s e gases, and i n t h e c a s e of p l a n t s p r o c e s s i n g on1.y a few tons per

day o f l50-day-decayed fliel, t h e y can g e n e r a l l y be r e l e a s e d through a

s t-ack t o t h e atmosphere without exceeding c u r r e u t di-scharge l i m i t s

Recent

s t u d i e s have shown, however, that t o av0i.d. exceeding t h e c u r r e n t g u i d e l i n e s

for r a d i a t i o n exposure of t h e publ.ic

a-L a s i t e boundary .that i.s 2 - t o - 3 k1~1

d i s t a n t , removal of noble gases may be required. i f t h e pI.ant c a p a c i t y exceeds about

tons/day of 150-day-decayed fuel.'

i f t h e fuel i s processed.

aftel. o n l y 30 days decay, as might, be t h e c a s e i n a f a s t - b r e e d e r economy,

removal mag be r e q u i r e d f o r plank capacit-ies of o n l y about 0 . 5 tons/day. Reprocessing cosi;s s c a l e so as t o f a v o r l a r g e r p l a n t s , and s i n c e t h e c o s t

of r a r e - g a s removal i s expec-ted t o be l e s s t h a n t h a t otherwise r e q u i r e d t o extend i h e site boundaries, t h e i r removal. can probably be j u s t i f i e d

economically as w e l l as from Lhe s Landpoint o f improved. pu'olic r e l a t i o n s . There a r e a number o f processes for s e p a r a t i n g t h e noble gases from

process o f f - g a s which are eitherr p r e s e n t l y a v a i l a b l e o r under development. 2 O f these, t h e jilost a t t r a c t i v e appear

in a f l u o r o c a r b o n s o l v e n t

'LO

be a process based- on a b s o r p t i o n

and. t h e cryogen7.c distil.l.at,ion process cur-

r e n i l y i n use a t t h e Idaho Chemical Processing P l a n t .

The absorptli.on

process has beern t e s t e d e x t e n s i v e l y on a p i l o t - p l a n t s c a l e , while t h e

cryogenic d i s LillaLion process has been s u c c e s s f u l l y a p p l i e d i n ac-Laal

plant operations.

99$

Each has t h e p o t e n t i a l f o r r e c o v e r i n g g r e a t e r t h a n

of t h e gases w i t h o n l y a p e r c e n t ,

o r jess, of n i t r o g e n and oxygen

impuribies i n t h e f i n a l product Once t h e noble p s e ~have been c o l l e c t e d , however, t h e r e i s less

ccrLainty how best to c o a t a i n them f o r t h e s c o r e s of yeRrs t h a t are req u i r e d f o r decay ol" rnost of +,he 85Kr t o s t a b l e 85Kb. One p o s s i b i l i t y might be t o i n j e c t Lhe gases i n i o porous nrdPrground Eormations. 596, I An aeccpiablc formation f o r t h i s purpose would have t o be o v e r l a i n w i t h

a capping formation of' v e r y low p e r m e a b i l i t y , b e f r e e ol' crszcks o r f'rac-

Lures, and be Located i n a zGne oi' lowest s e i s m i c r i s k .

Thess considera-

t i o n s appear to be t o o r e s t r i c t i v e i n deterrnii1in.g f u t l r e p r o c e s s i n g p l a n t s i t i n g requirements f o r t h i s method t o s e r v e as a geileraLly a p p l i c a b l e s o l u t i o n t o t h e prob.lem. Other possibilities wh1cl.i nave been suggested, arid i n ~ o m ec a s e s

investigates to 1ica"lted exLents, include d i s p e r s i o n oi' t r i e gases in glasses

or r e s i n s , arid entrapment in molecular s i e v e s , c l a t h r a t e s , w s n 3 a Z l press i l r i z e d s t e e l b ~ l ' n a which a r e i n

zux-n erieased i n eyoxy resin.

8 In oar

view, some of' t h e s e metliods may possi'oly have long-range a p p l i c a t i o n s , b u t t h e i r t e c h n i c a l . and economic p r a c t i c a l i t y can n o t be essat)lished imt 11

they have 1,eceived cons icieralbly more experimenffal doveloprzent On the other hand, we b e l i e v e t h a t a v a l i d and g e n e r a l l y a p p l i c a b l e

method f o r manageroent oâ&#x201A;Ź these g a s e s , reqisir-irg l i t t l e o r no a d d i t i o n a l

experimental development, i s t o e n c a p s u l a t e them in k i g h - p r e s s u r e c y l i n d e r s

and t h e n s h i p t h e c y l i n d e r s t o a s a l t - m i n e r e p o s i t o r y where they would be s t o r e d pemnanent,ly with the s o l i d i f i e d high-level wastes a l s o g e n e r a t e d

a t she reprocessing p l a n t s

T h i s proposed schedule of rriariagpment operations,

i n c l u d i n g handlirig and temporary storage or" zhe gases at the r e p r o c e s s i n g

pla~ts,shipment of the pressuxxized cyLlnclerS in s p c c i a l l y - d e s i ~ n c dcasks of high i n t e g r i i - y , and emplacement of the c y l i n d e r s i n r o o m mined i n a

s a l t formation, is examined below.

Y'hc aui;hors g r a t e c u i i y acknowledge the h e l p of

C. Ti. St;oddarS in

the concept.im-1 desieri of' a shipping cask f o r p.ess:irized

cyLinders of noble

gases, and of W. G . S t o r k d a l e in est,imatir& T . h e capital c o s t of' the gas

pac kaging f ac 1lit7

TTie charactel-istic:; oi' %he ribljle-gas f i s s i o n p r o d ~ i c t spresent i n n ton

o f spent, f u e l fYom a "ty-pical" light-water r e a c t o r (LWP), decayed 150 days, and- a liquid-metal-cooled

f a s t - b r e e d e r r e a c t o r (UGBR)

decayed 30 days and

150 days, are g i v e n i n T n L l c 1. Tnere a r e no s l g n i f i e a c L d i f f e r e n c e s i n the

c h a r a c t e r i s t i c s 01: niixtures from fuels havir*g equivalent exposures

Table 1. C l a r a c t e r i s t i c s of Noble Gases from One M e t r i c Ton of Spent F c e l

30 Lays Decay KT

Total

L;gnt-weter r e a c t o r a Gra;n- a t o m Czwies 0.514-Mev gamma d i s i n t e g r a t i o n s / s e c Seat g e n e r a t i o n r a t e , watts J1u;lbe-r of c y l i n d e r s r e q u i r e d b P a s t breeder r e a c t 3 r c Gram- atoim Curies Gama d i s i n t e g r a t i o n s / s e c 0.514 Mev 0.08i Mev Heat g e n e r a t i o n r a t e , sratcs Nm'oer of c y l i n d e r s required'

a.4

3.3

c.003

o .0516 31.9

330,700 3.0 x 1015

86.1

0 .O4l5

3 .?

35.6

31.9

7.4

10,200

90,900

i.5 x 1012

1.5 x 1012 3.0 1015 292.8 0.0515

16.4

3 .e100

3.007 0 .Oh15

LwEi f u e l exposed t o 33,000 h u / t o n a t 30 &/tor,. bGas contalned in 5 3 - l i t e r c y i i n d e r s , pressurizea to 2200 psig st 7 0'F. C U F B R n i x e 5 c o r e aria 5 l a i K e t s w i t h an a v e r a g e exposure of 33,000 &&/ton at

58 Piw/con.

150 2ays Decay

4 .4

I1,23G 1.7 x loi2 18.0 0.0105

3.7

Total

44.8

E, 20C 1.7 x 10l2 18.0

o .0621 35.6

10,000

10,00s

1.5 x io12

1.5 x 10~2

16.1

0.0;00

16.1

0.0515

5 Although f a s t - b r e e d e r fuels may b e processed w i t h cooling

and decay t i m e s

t i m e s OD o n l y 30 days, as compared w i t h 150 days for LWR i ' u e l s , the o n l y r a d j o i s o t o p e of consequence remaining a f t e r 3-50 days "in e i t h e r c a s e is

05Kr

A l l subsequeni; c o n s i d e r a t i o n s r e fer tcomixtures oi' this age o b t a i n e d

from the

f1Lel.s

d e f i n e d En Table 1.

The noble gases can b e h e l d i n s t a n d a r d 5 0 - L i t e r c y l i n d e r s ,

diam by 52 i n . h i g h .

Those conyorming t o ICC: S p e c i f i c a t i o n

w a l l t h i c k n e s s s l i g h t l y less t h a n l / l t i n . , weigh

135

in, in

have a

are normally

lb,

f i l l e d t o 2200 psig in n i t r o g e n s e r v i c e o Xenon and krypton are f a i r l y

compressible a t ambient temperat-wes, w i t h c o m p r e s s i b i l i t y i'acbors ( Z = PV/riRT) reachring m i n i m a o f 0 021for xenor: st

kl-ypton a t 2831 p s i a ,

880 psia,

and of '3 #72 Yor

G a s volumes p e r t o n o f f u e l processed a r e siinwn i n

F i g . 1 as f u n c t i o n s o f s t o r a g e pressure, A t 22OG p s i a f'or LWR r'uela, chese

valces a r e 0.1 i't,3/ t .o n i f bokn xenon and krypton a r e s t o r e d , o r 0,018 Ct3/ t o n i f t h e xenon i s s e p a r a t e d from t h e kry-pton and r e l e a s e d .

VoPmes

f o r LMFBR f u e l arc about 19% lower, A 2600-ton/ycar

(10tons/day) p l a n t p r o c e s s i n g LMR fuel wo~fidproduce

16C c y l i n d e r s p e r y e a r if both xenon and kry-pton are encapsulated, o r 28 c y l i n d e r s per y e a r if o n l y k r y p t o n i s s t o r e d .

11,200 c u r i e s / t o n , or abour, s t o r e d alone.

6 10

The krypton a c t i v i t y i ~ ,

c u r i e s p e r c y l i n d e r if the krypbon is

On t h e o t h e r hand, t h e a c t i v i t y of a c y l i n d e r e o n t a i n i m

both xenon and krypton i s l . @ J , O 0 0 c u r i e s .

ACCPDENI'AL REZEASE

The cmseq-.x?nees of an a c c i d e n t a l r e l e a s e were st,?ldied u s i n g- t h e

10 t o detcrmirle t h e n o o l e gas eoncen-

Gaussian plume formula ot' Ciffoid

t r a t i o n as a finnctlon of d i s t a n c e from Lhe source, and t i m e .

Damage would

occur by p e r s o n n e l exposure alone, s i n c e the g a s e s would n o t remain as contamination t o cause property damage

The xenon a c t i v i t y i s n e g l i g i b l e

and t h e most importarits exposu.re would be th? e x t e r n a l whole-body beta dose f r o m t h e krypton.

Fol.howing tthe forrnuLaticjn of Bicford,

the c o n c e n t r a t i o n i s g i v e n by

Barisl?, and Kam, LL

r--I

4 .o

-..

ORNL DWG 69-12143

___. -.-T

--.._.. ~

XENON C KRYPTON

v, Q

0.4

..-

0 w

KRYPTON

-I

0.W

. _ I . . . . .

fOO

{ bl:BR

1._..___L_I_L_LLLL_I I

4000

STORAGE PRESSURE (psi)

I l l 4 0,000

Frig. 1. Volwne of Noble Gases as a Func'clion of Pixssllrre i n a Ton of Spent; Fuel from Light-Water and Fast Breeder R e a c t o r s

where X = coneenLraLion, curies/m 3

= source StrengLh,

€ 5 ’

curies/min

= s t a c k f a c t o r , min/m 3 g The dose rate, D, i s d i r e c t l y p r o p o r t i o n a l t o t h e c o n c e n t r a t i o n . 12

where D

dose rate, rern/mi_n

85Kr)

CE = e f f e c t i v e energy p e r f3 d i s i n t e g r a t i o n , rnev ( O P 2 3 l o r

’a = d e n s i t y oP a i r (0.0012 g/cm3) Pa/Pt = s t o p p i n g power of a i r r e l a t i v e t o tissue (0,885for p p a r t i c l e s ) . The total dose is

l m D dT = 3.89(ZE)

X dT = 3.89(ZE)S

gJ0

Q dT.

According to Binl’ord e t al.,

wkiese

a = fraction A

Y;: ?I,

decay c o n s t a n t , min

-1

t o t a l moiunt of r e l e a s e , c u r i e s

wind v e l o c i t y , meters/min

x = dist,anee Assuming

o f a c t i v i t y r e l e a s e d p e r rnin

>>A

11-i

d i r e c t i o n of w i n d , meterss

and ( h x / u ) -0,

f a c t o r is

where y

5J7

Equation (L) reduces t o

horizontal d i s t a n c e p e r p e n d i c u l a r to wind d i r e c t i on3 meters

z = v e r t i c a l dfstance r e l a t i v e t o release p o i n t , meters

The s t a c k

= 4is p e r s i o n paramelxr 6, meters = stack

height, meters.

(3)

8 The c o n c e n t r a i i o n a t g r o m d l e v e l (z (y

0 ) reduces to

- h ) ; o t h e d i r e c t i o n of t h e wind

2 2 -h /20z e 'Tu0 u

Y Z

- 0_u 11

Tne e x p r e s s i o n f o r t h e toial dose ( E q . 3) car? be w r i t t e n i n t h e form

Values o f 0 a s f u n c t i o n s o f d i s t a n c e , x, and weather c o n d i t i o n s a r e p l o t -

ted f o r a s t a c k height, In, of 100 meters by Ililsmeier and Gi-fford. The -5 -2 maximum v a l u e of 0 i s 6.41 x 10 rn and O C C U ~ S a i a disidiice of 1400 meters wi.t,h

extremely u n s t a b l e weather c o n d i t i o n s ( c o n d i t i o n A )

c u r i e release and

a wind v e l o c i s y o f 100 meters/min,

ground l e v e l i s about 200 mrern.

At a s i t e boundary

For a l-rriillion-

Lhe maximum dose a t 1

km d i s t a n t ,

hi'

h i g h e s t value of 8 occurs w i t h s l i g h t l y u i s t a b l e c o n d i i i o n s ( c o n d i t i o n C ) a n d yields a t o t a l d o s e o f 120 mrerfl.

For a -release a t a h e i g h t of 30

meters, t h e maximum dose with any Iweaiher c o n d i t i o n s and a wind v e l o c i t y o f 100 m/sec is l e s s t h a n

1 5 rem.

Present r e g u l a t i o n s (10 C'FX 20 a n d 10

CVLI 100) s p e c i f y ihat c'flroii i c exposures of average popiil a t i o n groups s h a l l

not exceed an annual whole-body dose o f 7-70 mem, and suggest t h a t a c u t e

whole-body exposures r e s u l t i rig from a c c i d e n t s should riot r e s u l t i n a dose g r e a t e r than 25 rem.

Although Lhere i s I _ i + , t l e i n c e n t i v e Lo keep the gases o n - s i t e Cor any

Lime longer than n e c e s s a r y io f i l l a shipping cask, a s t o r a g e f a c i l i t y f o r

a 2i;OO-ton/year p l a n t w o u l d n o t be l a r g e o r Expensive, even if tlie gases

were s t o r e d for 10-to-20 y e a r s . either air or waier,

Ihe cyl-inders could be s',ored s a f e l y i n

provided t h e y were s e c u r e l y anchored i n comparLments

or e n c l o s u r e s Ynat afforcjed p r o i e c t i o n against impact by an a c c i d e n t a l l y r u p t c e d cy1 I n d e r .

However, t h e requiremenis f o r b i o l o g i c a l s h i e l d i n g aiid

heat d i s s i p a t i o n would tend to f a v o r t h e use of w a t e r - f i l l e d canals for i n t e r i m s t o r a g e whether kl-ypton was store3 s e p s r a t e l y , o r mixed

i t ' n xenon.

9 If tne c y l i n d e r s a r e Silied with krypton alone, an3 st30reli011 2-Yt

cencers, a 1itLl.e inore t h a n 100 Yt

y e a r ' s p r o d u c t i o n of 28 c y l i n d e r s is

5820 Etu/hr, and iE

of' f l o o r area i s r e q u i r e d f o r one

The h e a t - g e n e r a t i o n rate of

cylinder

i t i s conled i n air by n a t u r a l convection and

radiation, t h e c y l i n d e r would reach a temperatwe af s h o u t 315째F.

Yqese c y l i n d e r s woiild i-equire aboixt 2 6 inches of l e a d shielding for t h e dose I

rate t o be reduced tto 10 mrern/hr a t 1 meter.

Ii' lrrypton and xenon &re not separated, the 160 c y l i n d e r s produced

a y e a r would r 3 : q u i r s about

2 f t of si:,oruc<e floor area,.

t h e h e a t - g e n e r a t i o n r a t e p e r cylillder i s 9W Btu/hr,

i.n

Srz this case,

and t h e shielding

requirement i s 0.8 i n . oP l e a d .

The s h i p p i r g cask i s b a s i c a l l y a t a n k f i l l e d with w a t e r (Figo 2 ) .

i s a m o d i f i c a t d o c of' one which has been shown t o m e e t t h e impact, punctu.re,

and r " i ~ er e s i s t a n c e s p e e i f i e a t i o n s of t h e AEC Mknual, Chapter '3j29,and

which has been l i c e n s e d f o r s h i p p i n g c a p s u l e s of curium oxide.14 'The eahk is 5 f't. i n diarneber, i s made oi' 1 - i n , - t h i c k , is

t y p e 3Ol+ st2inless styel., and

equipped w i t h exteriial f i n s t o enhance h e a t d i s s i p a t i o n ,

The .tJater

provides shielding, serves as a heat t r a n s f e r medFilnl, and provides t h e heat, c a p a c i t y needed t o w i t h s t a n d a

14750F

f i r e f o r 30 rriinutes.

p s i g r u p t x r e disc i s provided as a s a f e t y measure i n a d d i k i o n to i ~ l u g k , ,

A ?GO

16 fusLbLe

which are designed t o allow s t e m to escape in cas? of a f i r e ,

a d d i + i o n , a vapor space is provided s u f f i c i e n t l y lar-ge to .hold t h e eonTents 01' a l e a k y c y l i r i d e r without causing t h e riApture disc t o v e n t .

Iii

tLc dirneris ions chiiwn, Lhc e y l i r d e r cempcraturc w o u l d be a o o u t 29

u. cask of

at-o~e

tine ambient, and t h e r a t e of h e a t d i s s i p a t i o n wouLd b e suft'f'icicnt i"or o m

cylinder of krypton, o r abol-st 5 c y l i n d e r s of krypton-xenon mixt,ilre.

7 tons and we esttmate it would c o s l about cars, 40 to '(0F ' t i n l e n g t h , c o u l d CRITY

'loaded c a s k would t7eigh a'ooiit $k),CJOO

S t,aridur.d r a i l r o a d

s e v e r a l casks,

z W > >

..J

0 ..d

U Lld

r1 >-

0 v)

6 (3

Ill

3 v)

-=I

w J m U o_

LI.

-1

w v)

6. PmmNm

STORAGE

The cylllnders could be stored pe-rmanently i n a zalc m i n e o p e r a t e d f o r

d i s p o s a l oi' s o l i d i r i e d k i i g h - l e v e l l'uel- reprocessing waste^ T ' O ~h i g h - l e v e l

wastes a r e to p l a c e them i-n h o l e s

il?

Current p l a n s

t h e f l o o r 07 roans

mined i n s a l t and, a f t e r f i l l i n g , t h e rooifis would be b a c k f i l l e d w i t h crushed ?-!j

s a l t and sealedo

Disposal ic t h e f l o o r i n this manner w a s conceived

p r i m a r i l y because of t h e s h i e l d i n g requirements fol- p e r s o m e 1 protecti-on. Cylinders of compressed gases, requiring only light, s h i e l d i n g , could be

placed i n racks above t h e i n h e f l o o r and t h e rooms sealed withonti bhckâ&#x201A;Ź i l l i r i g w i t h saltJ

'Tke c a r b o n - s t e e l c o n t a i n e r s ,

i n contact only w i t h d r y

air on t h e outsiile and noble gases on t h e i n F i d e , and i s o l a t e d from

short-term teuiperature Yluctuat,ions, should l a s t many decades arid perhaps

c e n t u r ? es

Lf t h e c y l i n d e r s were stoTed i n t h e imrnediatc v i c i n i t y of the h i g h - l e v e l ri

wastes, t h e y w o i ~ l devent,ually r e a c h a tempel-ature of' 200 C and a p r e s s u r e

of 3>00 p s i g .

'IhcseL'ore, i t might b e d e s i r a b l e t o f n c r e a s e t h e c y l i n d e r

w a l l t h i c k n e s s by 1/8 i n c h .

Zke a l l o w a b l e h e a t - g e n e r a t i o n r a t e p e r u n i t 7

area oP mine i'loor trolild be about 15-to-20 Stu/hr-ftJ-;

t h e r e f o r e , t h e space

reqiiirements for a 2600-ton/year p l a n t a r e about L / h acre p e r y e a r f o r t h e

g a s e s as opposed t o about h i g h - l e v e l wastes,

16 ames p e r year f o r 6-year-old s o l i d i f i e d

'!ke econorriie i'easikJfli1dy of' t A e scheme wzder cor.!sideration i s indl-

c a t e d 'oy a cost, esti.mat,e based on t h e r e y u i r e n e n t s for a 26OO-ton/year

reprocessing planl, s t a g e s ::

The sequence of o p e r a t i o n s is d i v i d e d i n t o three

(1) f i I P i i ; g , t e s t i n g ,

temporary s t o r a g e of cylinder;;

(2)

shipinerlt~ o f ' talle eyL2riler-o t o a s a l t mine; and ( 3 ) permanent storage i n t h e

mine

A cell equipped f o r rilling and t e s t i n g cyl~nderswould. be contiguous

t o Lhu fuel r e p r o c e s s i n g plant, t o f a c i l i t . a t o t h e t r a n s f e r of t h e P o b l e g a s e s

afker t h e y have been s e p a r a t e d Prom t h e process off-gas; t h e r e f o r e ,

the

same c a n a l used t o s t o r e s p e n t f u e l and/or cans of s o l i d i f i e d h i g h - l e v e l

wasies can also b e used t o s t o r e t h e gas c y l i n d e r s (F'ig.

3).

The c y l i n d e r s

are ninved from one s t a t i o n t o zhe next by a d o l l y equipped with a

motor-driven chain d r i v e , and t h e y a r e unloaded and placed i n a c o r n e r of t h e s t o r a g e c a n a l w i t "

a hand-operated chain h o i s t suspended P r o m a

A compressor t r a n s f e r s t h e noble g a s e s from a gas h o l d e r (not

xcnorail,

shown i n F i g o

3) and comprPsses ihem i n t h e c y l i n d e r s .

After a cylinder

i s f i l l e d , a vacuum pump i s used t o evacuate t h e l i n e s and r e t u r n t h e

r e s i d u a l gases t o t h e h o l d e r , i s

During t h e f i l l i n g opern,tion, t h e equipneat

o p e r a t c d from o u t s i d e t h e c e l l , and a l e a d - g l a s s window i s provided f o r

"he c e l l c o n t a i n s a shadow-shiel-d, however, t o enable many oper-

viewing.

a i i o n s such as g a s - l i n e connections t o t h e c y l i n d e r s , removal of t h e f i l l e d c y l i r d e r s from i h e d o l l y , and maintenance of t h e compressor and vaciiixn pimp t o be per-fomed by personnel i n t h e c e l l .

'I%e v e n t i l a t i o n a i r i n the

c e l l i s monitored continuously f o r 85K~,and p r o v i s i o n s a r e made t o seal t h e c e l l a u t o m t i c a l l y and c o n t a i n t h e 2 i r i f r a d i o a c t i v i t y i s d e t e c t e d . Pn such a c a s e , the a l r I n t h e c e l l could be r e c y c l e d t o t h e noble-gas s e p a r a t i o n p l a n t f u r decontamination. jng either the

T h i s f a c i l i t y i s capable of packag-

160 e y l i n d e r s / y e a r of krypton-xenon mixtures, or t h e 28

c y l i n d e r s / y e a r t h a i would be r e q u i r e d i f krypton, alone, were t o b e encapsulated.

The t o t a l c a p i t a l c o s t of t h e f a c i l i t y i s est-imat,ed to b e $230,000 (Uable 2 ) .

T f t h e equipment i s amortiLed over 10 years, and Gbr s t , r u c t u r e

over 20 years, a t

$?4,000 (Table 3)*

based

+, c a p i t a l cost is i n t e r e s t , iiie e c p ~ i v a ~ e nannual The cost, o f t h e c y l i n d e r s should not exceed $100 ezch,

t h e cost, o f o r d i n a r y n i t r o g r q r y l i n d e r s of aboL,i $50.

Therefore,

t h e anfilial c y l i n d e r c o s t Is $16,000 f o r krypton-xenon mixtrures, o r $2800 f o y krypfon, a l o n e .

Annual o p e r a t i n g c o s t s , based on an estimated r e q u i r e -

menL of 1 man y e a r Tor mixtures and 1/? man y e a r for krypton are $20,000 and $10,000,

respectively.

Shipping costs c o n s i s t o f t h e cask c a p i t a l c o s t s , f r e i g h t , and l a b o r

cosis.

For r o u n d - t r i p shiprients of 1000, 2000, and 3000 m i l e s , i r a m i t ,

times ( f . e . , Lhe

'Limes

cask) are e s t i m a t e d a t

r e q u i r e d between s u c c e s s i v e shipments in the same

7 , 9, and 11 days.

Therefore, even f o r t h e l o n g e s t

ORNL DWG 69-12(54 WATER-Fl STORQGE

SCALE IN FEET

Table 2 - Eszimateil Costs of a Krypton Packaging F a c i l i t y

---_--_..-

I -

Equipment Modjfied H

2000 p s i g ,

&-stage compressor

Remote welder

$ 12,000 50 ,ooo

Chain h o i s t , monorail, hand-operated

Uol1 y, r a i l s

500 I., 000

motor-driven c h a i n d r i v e

1,000

Vacivm punp Sub iotal

$ 6k,500

Contaim-en t structurc:

$ 26,000

Concret e

15,000

Door ( l e a d a n d s t e e l ) and window

4,000

V e n i i l a t i o n sys icm Painting

2,000

E l e c t r i c a l , lighting

I,000

Flooi- d r a i n and normal w a t e r p i p i n g

1,000

$ k9,000

Subt o t a l "R I'

$ 3,000

Piping, process

Electrical, process Subt ot a1

2,500

$ 5,500

Radiation d e t e c t i o n

j nstruments

Construciion overhead

(subtotal "D")

35% o f "A, R,

C, D"

Contingency

254 of above

P r e l i m i n a r y budget e s t i m a t e

5% of

2,000

42,000

$l53,000

Subt c i a 1 "E"

A r c h i t P c t e n g i c e e r ajiocat I o n , 12

I'Ii''

$i20,000

46,

000 -.-._sl_l__

$230,000

Table 3 .

Estimated Annual Costs of Noble Gas Waste Management

for a 2600-ton/year Reprocessing Plant (Exclusive of

as Separations

Krypton and Xenon

Cost)

K r y i , ton

1 Gas encapsulation Capital cost

C y l i n d e r cost

Operating cost

Subtotal.

$ 24,000

16,000

20,000

$ 24,000 2 , &io

10,000

$ 60,000

$ 35330

$ 10,400

9; 10,400

Shiprrient Cask

Freight Iabor

Su b t ota1

Salt mine storage Total

23,600

29?000

$ 63,000

$ 959 300 $218,300

700

25,000

$ 56,100

9; 95,300

$I 88,2uo

16 d i s t a n c e considered, one cask could make t h e reqiiired 32 t r i p s p e r y e a r . A s p a r e cask i s supplied, however, a t $40,000 p e r cask, and a m o r t i z a t i o n

over I O y e a r s a t

of $10,400.

j n t e r e s t r e s u l t s i.n an e q u i v a l e n t annual c a p i t a l c o s t

Erei-ght r a t e s a r e e s t i m a t e d a t 29, 53, and 78 d o l l a r s per

toil

for

one-way shipments of 500, 1000, a,nd l 5 O O m i l e s , w i t h rates 3O$ lower f o r r e t u r n of einpty c a s k s .

'The casks weigh about

7 tons, loaded, and 3-1-/2

i o n s w i t k h t h e c y l i n d e r s and water removed; and t h e f r e i g h t c o s t f o r 32 l500-mile shipments, with each shipment c o n s i s t i n g of w i t h krypton and xenon, i s $23,600.

5 cylinders f i l l e d

For 28 shfpments p e r year, with each

shipment c o n s i s t i . n g of one c y l i n d e r f i l l e d with krypton, t h e c o s t i s $20,700.

Labor requirements f o r loading, u-nloading, and maintaining the casks a.re e s t i m a t e d t o be 9 man-days p e r t r i p , and a t $1.00 p e r man-day ( i n c l u d i n g overhead), l a b o r c o s t s of $29,000 p e r y e a r are es-timated t o r shipping krypton-xenon mixtures and $25,000 p e r y e a r for shi-pping krypton a l o n e . A s a l t - m i n e r e p o s i t o r y f o r h i g h l y a c t i v e s o l i d i f i e d wastes has been

e s t i m a t e d i o c o s t $381,000 p e r a c r e o f mine area, i n c l u d i n g a l l c a p i t a l and o p e r a t i n g expenses

14 A s d i s c u s s e d previousl-y, t h e noble gases, w i t h

a n e f f e c t i v e h a l f - l i f e of about 10 y e a r s , ?an h e s t o r e d s o t h a t t h e y r e l e a s e

about

1-5 B t u / h r - f t 2 of mine f l o o r .

'Therefore, about 0.25 a c r e s / y e a r of mine

space a r e r e q u i r e d â&#x201A;Ź o r e i t h e r t h e mixed noble g a s e s o r f o r krypton a l o n e . The permanent s t o r a g e c o s t i s $95,300 p e r y e a r . 'lhe t o t a l e o s i of t h e packaging f a c i l i t y , f r e i g h t , and permaneni s%orage fs about $218,000 p e r y e a r f o r krypton-xenon mixtures, and about $188,000 per y e a r f o r krypton.

r e p r e s e n t s 'ihe production of

Considering t h a t i'lie 2600 tons of f u e l

6.6 x

7.0'

kwhr of e l e c t r i c i t y , t h e s e c o s t s

correspond t o 0 .OOO3 and 0.00035 mills/kwhr,

respectively.

8. -_YEOJECTED SCALE OF OPERATIONS CIVILIAN

irL

Table

4, each

NUCLEAR POWER

FOR 'TEE

PROGREIM

a s p e c t of t h i s proposed managemelit scheme i s pro-

j e c t c i l f o r a nuclear ccononiy which r i s e s from an i n s t a l l e d c a p a c i t y OP 14,000 Mw i n 19'[0, t o 1.53,000 Mw i n

1980, and t o 735,000 Mw i n

2000.

Table 'I-. Pr,i,jected Nsiblc Gn:, bknsgernent i'or C i v i l i a n Nuclear Puwer Program

aHuseci c3ri an average expo:,lu'e of 33,000 Mwd/ton, ami a delay OS ?: yeam between power bgeneration and fuel p r ~ c Assimes ga:;er; are s h i p p e g t h e year f'uel i s processed, and that 5 casks p e r ra. car c o r l s t i t i i t c 1. shipment. 'A:;sumes gases a r e b u i e d d w i n g the year f u e l i s pr'oces:;ed at?d t h a t h i g h - l e v e l : ; o l i d i t'ied waaLes a r e decayed 6 year:: before b u r i a l .

Reasonable numbers of pressiu'i.zed cylinders, casks, and shipmenis per year

If a shipment consists of a single railroad car carryir,g 5 casks, only about 30 shipments per year would be required in the year

c m be anticipated.

2000, and on the average, there will never be more than one loaded shipment

in transit at the same time.

Only

1-7acres

of salt mine area would be

occupied by the gas cyl-inders, compared with more than 600 acres devoted

to high-level s o l i d i f i e d wastes. None of these considerations are of a

magnitude as to cause concerfl with respect to their technical feasibility.

1. Oak Ridge N a t i o n a l LaboraLory S t a f f , e t al

Siting of Fuel Reprocessin6

" )

Plants and Waste Management F a c i l i L i e s , ORNL-4451 ( t o b e published)

C . 14. Slansky, H. K O Peterson, and Vernon G. Johnson, "R~clearPower

Growth Spurs I n t e r e s t in Fuel P l a n t Wastes,

-3,

hbviron. S c i . Technol.

446 (1969>..

3. J. R. Merriman, J. H.

Pashley, K. E. Habiger, M. J . Stevenson, and

I,. W. Anderson, "Concentration and C o l l e c t i m of' Krypton and Xenon by S e l e c t i v e Absorption in Fluorocarbon S o l v e n t s ,

Synposilun on O p e r a i i n g

and Developmental. W p e r i ence in t h e Treatmenr, of' Airborne R a d i c a c t i v e

26-30, 19681,

Wastes, Uait<ed Nations Headquarters, New York (August,

SM-110.

L. Bendixen and G. F. Offutt, Rare G a s Recovery F a c i l i t y a t t h e

Idaho C'nemicai P r o c e s s i n g P l a n t , I N - 1 2 2 1 (Apr5.l

5. P.

C e Reis:,,

Media,

"Disposal of Waste R a d i o a c t i v e Gases i n Porous Ufldergroland

Nucl. A p p l .

6, J e Tadmor

1969)

and K.

& 4-75 (1967) I

Cowser, "Undergrour~d Disposal ol' Kry-ptan-85 from

NQclear Fuel Reprocessing P l a n t s , " Milcl. b g . Design 6,

J. F

243 (1967).

Robertson, Benavior of Xenon-133 Gas Afzer :InJe@tion Undergrcurld,

IDO-22051 (July 1969)

W., E. C l a r k and X , E, Blanco, Encapsulation of Noble F i s s i o n - P r o d u c t

Gases in Sol i d M e d i a P r i o r t o T r a n s p o r t a t i o n and Storage, ORNL-4473 ( i n press)

Pa-ragraph '78,3T9 "Spee;fiea?,lon '%A,"

T a r i i ' i Nc

19:

187 in Agent T.

George's

I C C R e g u l a t i o n s f o r T r a n s p o r t a t i o n of' Explosives and

O t h e r Dangerous Ar-zirles by harid and Water i n Rail Freight. S e r v i c e and

I _

by 34oLor Vehj r l e (Highway) and Water, I n c l u d i n g S p e c i f i c a t i o n s for Shipping Containers, New York,

1966,

LG- F. A , Gifl'ord, The Probiem of F o r e c a s t i n g D i s p e r s i o n in t h e Lower A+,mosphere, - DI'IE, USAEC,

Oak Ridge, Tennessee,

1961

20 11. F.

T. Binford, J . B a r i s h , arid F. B o K. Kam,

ESiilIldtiOil

of Radiation

Doses Fo7 lowing a Reactor Accident, ORNL-4086 (February 1968)

L n t e r n a t i o n a l Commission on R a d i o l o g i c a l P r o t e c t i o n , Reconmendations of

the Inlerna.t:'olial Comnissi on on R a d i o l o g i c a l P r o t e c t i o n (Report of

I _ -

I-____

Coiuraittee 2 on P e n i i i s s l b l e Dose f o r I n t e r n a l R a d i a t i o n) , XHP f3Ablo 2, Pergalnan, London, 1959; Health Phys. 3 (June 1960) I

13.

W . F. Hilsmeier and F. A. G l f f o r d ,

Dispersi on, ~-~

ORO-

Graphs f o r Estimating Atmospheric I

545 ( J u l y 1962,)

14. G. A . Wilkins, R. 1). Kelsch, F. H. D. King, D. 5. Stoddard, J, Pe F a r a c i , ar,d ,To W. Langhaar, "Design and T e s t i n g o f C u r i u m Shipping Capsole and

Cask," Proreedings of t h e Second i n t e r n a t i o n a l Symposium on Packaging I_____

I _

and T m a s p o r i a t i o n of R a d i o a c t i v e Materials, October 14-18,

I_______I_

1968,

cow- 681001 l > o 13. L. Aradshaw, J. J. Pcrona, J. 0 . Blomeke, and W. J . Boegly, Jr.,

Evaluation o f Ultiiiiate Uisposal Methods for Liquid and Solid R a d i o a c t i v e Wastes. VI. Disposal of S o l i d Wastes i n S a l t Formations, ORNL-3358 1 1 1

I__-______

(Rev.) (-%rch

16*

1969)

R. L. Bradshaw and W. I.,. McClain, Oak Ridge N a t i o n a l Laboratory,

p r i v a t e communication, June 2'7, 1969.

tâ&#x20AC;&#x2122;

EXTERNAL DISTWIRUTION

88,. 81 *

83 84 85 86-100 181 102 103 104 105 106 107 108 109 110, 111. 112, 113, 4

C.B, Bartlett, MC, Washington Beltear, AEC, Washington

W.G. A.G, J.A.

B l . a s e w i t z , PNL Buckham, Idaho Nuelear C a r p , , 1dlah0 Pails, Idaho COB. Cosley, PNL D.F. cope, Site Office, ORNL D%visRon o f Technical Information Extension Laboratory SS UnFversfty Dbviofon, OR0 L . P , Hatch, BNL s. Lawroski, M L $.A. Mason, M4T J.A, Nc3r%de9 AEC, Washington AA,P* Perge, k%C, WaShingtQn A0M, B 1 H l t t 9 PNL ?delie Regan, AEC, Washington B O B . Richard$, GE, San Jose, California B.L, Sehmalz, AEC, Idaho Palls, Idaho K . E , Scbsaaider, PNE C,M. Slansky, IMA, Vienna E,J, Ifu&hiill, BNL