X-822

OAK RIDGE NATIONAL LABORATORY Operated by

UNION CARBIDE NUCLEAR COMPANY Division of Union Carbide Corporation

Post Office Box X Oak Ridge, Tennessee

ORNL CENTRAL FILES NUMBER

60-6-52

DATE: June.lQ, I960 External Distribution Authorized

COPY NO. £~3* SUBJECT: Actiyity in the HFIR Primary Coolant System after a

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

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Introduction

Shielding is being planned for the HFIR primary coolant system to provide protection against radiation in case of a meltdown of the fuel element in the reactor. Fission products are released from the fuel in varying amounts during the meltdown, and some of them may adhere to the walls of the cooling system. Demineralizer and off-gas facilities are being planned to provide cleanup of the primary coolant water. This report is a summary of the work of estimating the activity in the cooling system after such a meltdown.

?§I?§§§_°f_l'i55l2D_?E2£jy£:ts_from_Meltd̂

On the basis of the melting of several irradiated aluminum clad fuel plate specimens, •*• Parker and Creek2 stated at a meeting of interested persons that the release of the following percentages of fission products during the melting of the HFIR fuel would be conservative:

Element Krypton Xenon Bromine Iodine Selenium Molybdenum Tellurium Technicium Ruthenium Rubidium Cesium Strontium Barium All others

% Released 100 100 10 10

< 1 for oxide fuels ~ 0 for alloy fuels

< 0.1 < 0.1 < 0.1 < 0.1

0

These values are based on experiments on the melting of the fuel specimen in air.l Melting these specimens in a pool of water would result in the escape of less than 1% of the halogens and l̂ ss than 50% of the rare gases to the air.2 The other fission products are retained in the water. For the purposes of these calculations, it is assumed that all of the fission produces released from the fuel are kept within the water system immediately after the meltdown of the fuel.

3-

The buildup of the fission products in the HFIR fuel can be estimated from charts prepared by Blomeke and Todd.3 For the purposes of these calculations, it is assumed that the HFIR core contains 6 kg of U-235 which has operated for 10 days at 100 Mw.^ The charts prepared by Blomeke and Todd are based on a fission cross section for uranism-of 580 barns. An "effective neutron flux" which was used for these calculations was computed using this cross section and it is 3.U8 x 1 0 ^ neuts/cm2-sec. Table I shows the amount of fission products mentioned above in the HFIR core after 10 days operation at 100 Mw. Using the above valuesusf the percentagesiof fission products released into the coolant during the meltdown, the amounts of fission products in the cooling system immediately after the meltdown of the HFIR core were calculated and are shown in Table I.

^§2EP£i°B_2f_the_Fission_Produc^s^on_the_Coolant_Syst

Little is known regarding the adsorption of the fission products released during the meltdown on the walls of the coolant system, particularly at the HFIR conditions.5 The effect of temperature and pH on this deposition, is not well known, and quantitative information is limited. Edwards, et al, ran tests in a mild steel loop at 180 psi and 6t)°C. This loop was pretreate'd with a sodium silicate solution to provide a protective layer against the corrosion of the mild steel. The inpile section of this loop was aluminum and it con-tained an unclad piece of enriched uraniiinl-zircaloy alloy. The pH of the water in this loop was usually 5.5 to 6»5, but it occasionally had risen to 8.5. On the basis of the information presented in this report," the following atom ratios of fission products deposited'-on'the'walls to those'dispersed in the coolant are assumed:

atoms fission product on surface Element atoms fission product in coolant

pH = 7.0 pH = 5.0

Kr, Xe 0 0 I, Br 2.0 3.0 x 102 Se, Mo, Tc, Ru 1.0 1.3 x 103 Te 15.0 1.5 x 103 Ba, Sr 2.5 5.0 x 101 Rb, Cs 0 0

Since the values at a water pH of 5.0 are higher and since the reactor probabjy will be operated at this condition,7 the ratios at this pH are used. Assuming that the deposition of the fission products on the cooling system surface is runiform, a system volume of 30,000 gal, and a surface area of 35>000 ft2,8 the fission product activities immediately after meltdown are shown in Table I.

TABLE I Fission Product Activity in the HFIR Primary Coolant System

after Meltdown

Isotope Half-Life

Kr-83m Kr-85m Kr-85 Kr-87 Kr-88 Kr-89 Kr-90 Kr-92 Xe-131m Xe-133m Xe-133 Xe=135m Xe-135 Xe-137 Xe-138 Xe-139 Xe~l40 Br-82 Br-83 Br-84 Br-85 Br-87 Br-88

1-130 1-131 1-132 1-133 1-134 1-135 1-136 1-138 1-139

ll4m 4.36h 10.27y 78m 2.77h 3.18m ~ 33s 3-0s 12. Od 2.3d 5-27d 15.6m 9.13n 3.9m 17m 4ls l6s

35.87h 2.4h 30m 3-Cm 55.6s 15.5s 12.6h 8.05d 2.4h 20.8h 52.5m 6.68h 86s 5.9s 2.7s

Core Content After 10 Days Operation, Atoms

1.46 x 1020 1.02 x 1021 8.0 x 1021 5.7 x 1020 I.65 x 1021 4.1 x lO1^ 6.2 x IO18 3.5 x IO1? 2.5 x 1020 1.25 x 10 2 1 9.1 x 1022 7.7 x 1019 1.97 x 1020 6.16 x IO1? 2.5 x 1020 8.8 x IO18 2.7 x IO18

7.1 x IO1? 1.82 x IO20 9.1 x lO1^ 1.22 x 10j9 8.5 x iois 1.97 x 10xo 6.0 x IO18 U x IO22 1.53 x 1021 2.2 x IO22 1.08 x 1021 6.5 x 1021 1.22 x IO1?

Isotope in Coolant System After Meltdown

Atoms

1.46 x IO20 1.02 x 1021 8.0 x 1021 5.7 x IO20 1.65 x 10 2 1 4.1 x IO1? 6.2 x 10 l t t 3.5 x IO3-?

2.5 x IO20 1.25 x IO21 9.1 x IO22 7.7 x 10l9 1.97 x 10^u 6.16 x 109 2.5 x IO20/ 8.8 x IO18 2.7 x IO18

7.1 x IO16 1.82 x 10±y 9.1 x lOl8 1.22 x IO18 8.5 x ION 1.97 x IO1?

6.0 x lO^ 4.8 x 102J 1.53 x IO20 -21 2.2 x 10' 20 1.08 x 10' 6.5 x IO20 1.22 x 10j°

9.1 x lÔ -J 9.1 x IO16 5.5 x 10 16

Coolant Activity Immediately

After Meltdown dis/ml sec

1.30 x IO8 4.0 x IO8 1.54 x IO5 7.4 x 10° 1.01 x 109 1.31 x lo9 1.15 x IO9 7.1 x IO8

1.47 x IO6 3.8 x 107 1.22 x 109 5.0 x IO8 3.7 x 107 1.6l x 10° 1.50 x K>9 1.31 x io° 1.03 x 109 1.12 x 10 4.3 x IO1*-1.03 x 105 1.38 x 105 3.1 x 105 2.6 x IO5

2.7 x IO2 1.41 x 105 3.6 5.0 7.0 5-5 2.9 8.4

105 105 105 io5 102 id*

Surface Activity Immediately

After Meltdown dis/cm2 sec

1,16 x IO4 4.5 x IO7 1.07 x IO8 1.44 x 1J 3.2 x IO; 2.7 x 10'

8 8

,8 x 105 ,46 •"• i n 8

3-7 5.2 7.2 5.7

x 1] x 10! x x x

10fl IO8

5-5 x lO^ I.89 x IO2*"

3.0 x io5 8.8 x 107 1.97 x IO7

Coolant Activity 24 hours

After Meltdown dis/ml sec

1.21 x K A 4.2 x IO"2 7-3 x 10' 9.7 x 10' 1.12 x 10

4 6 -2

1.09 x IO3 3.0 x 1& 5.2 x 10§ 3.1 x 10° 1.21 x IO6 1.88 x IO" 1 1

6.7 4.0 x 10 3-3 x 10

6.7 x 10 1.21 x 105 3-5 x 10J 2.5 x IO5 5.2 x 10-3 4.4 x 10^ I.36 x IO2

Surface Activity 24 hours

After Meltdown dis/ cmc sec

6.9 x IO3 4.1 x 107 3.4 x XT

7.0 x 10* 1.25 x 10° 3-7 x lOl 2.6 x 10° 5 ^ 4.6 x 107 1.42 x IO5

TABLE I (continued)

Isotope Half-Life

Se-77m Se-79ra. Se-79 Se-8lm Se-8l Se-83 Se-84 Mo-99 Mo-101 Mo-102 Te=125m Te-127m Te-127 Te-129m Te-129 Te~131m Te-131 Te-132 Te-133m Te-134 Te-135 Tc-99m Tc-101 Tc-102 Tc-107 Ru-103 Ru-105 Ru-106 Ru-107 Rb-86 Rb-88

17.5s 3.9m ,

.5 x 10V 56.5m 17m 25m ~ 2m 67h l4.6m 12m 58a 90a 9-3h 33d 72m 30h 24.8m TJh 63m 44m < 2m 6.04h l4.0m < 25s < 1.5m 4ld 4.5h l.Oy 4m 19.5d 17.8m

Core Content After 10 Days Operation,, Atoms

1.40 x 10^ 3.7 x 1017 1.06 x 102J 1.20 x IO 1 8 9.4 x 1017 -1.20 x 10^9 6.0 x IO 1 8

6.0 x IO 2 2 1.93 x IO 2 0 1.34 x 1Q20 6.0 x IO 1 6 8.0 x IO 2 0 2.4 x IO 2 0 8.3 x 1021 1.40 x IO 2 0 2.2 x IO 2 0 1.94 x IP 2 0 4.9 x 10 1.03 x 10' 7-9 x lOfO 2.3 x IO1*

,21

5.5 x 102° I.85 x IO 2 0 4.6 x IO 1 8 6.3 x 1017 6.9 x IO 2 2 6.3 x IO 2 0 1.05 x IO 2 2 2.2 x IQ 1 8

4.5 x 10l8 1.73 x 10 ,20

Isotope in Coolant System After Meltdown

Atoms 1.40 x IO 1 2 3.7 x 1015 1.06 x IO 1 9 1.20 x IO 1 6 9.4 x 1015 1.20 x 10j7 6.0 x IO 1 6

6.0 x 102°ft 1.93 x 10?-° 1.34 x IO 1 0

6.0 x lp1^ 8.0 x IO 1 8 2.4 x IO18 8.3x 10l9 1.40 x 10J8 2.2 x IO 1 8 1.94 x IO 1 8 4.9 x IO 2 0 1.03 x 10l9 7.9 x IO 1 8 2.3 x IO1? 5.5 x IO 1 8 I.85 x lOj 8 4.6 x IO 1 6 6.3 x 10!5 6.9 x loJ-9 6.3 x IO1' 1.05 x IO19 2.2 x lO3^ 4.5 x 1015 1.73 x IO1?

Coolant Activity Immediately After Meltdown dis/ml sec 3.8 x 10=1 3-1 x 10 3.4 x 10=5 1.66 x 10 4.3 x 10 3.8 x IO2 2.4 x 103 1.17 x loj1" 1.04 x IO4 8.7 x 103

10" 4.9 x ^ 2 2.9 x icr 1.18 x IO2 I.32 x 103 8.3 x IO2 5-3 x 10| 7.2 x 103 1.11 x IO4 1.22 x 10* 7.8 x IO3

1.19 x IO3 1.04 x IO4 8.6 x 103 3.3 x IO2

9.2 x 10 I.83 x IO2 1.57 4.3 x 10 I.63 x 10 9.9 x 10?

Surface Activity Coolant Activity Immediately 24 hours

After Meltdown After Meltdown dis/cm sec dis/ml sec

I.69 x 103 1.34 x 105 1.10 x lp-1 8.8 x IO1* 1.95 x 105 I.69 x 10° 1.06 x 10' 5.3 x 107 4.7 x 107 3.9 x 107 2.5 2.2 x XT 1.52 x 10L 6.2 x 10§ 6.8 x 10° 4.3 x 10° 2.8 x 3.7 * 5.8 x 6.3 x 4.1 x

107 io? 107 107 lo7

5.4 x 10° 4.7 x 107 3.9 x 107 1.48 x 10° 4.1 x 105 8.2 x 10? 7.1 x IO3 I.94 x lo5

2.4 x 10-5 3.6 x IO"6

8.9 x IO3

4.7 x IO"1* 4.0 5.1 x 10 1.14 x IO2 1.14 x IO2 3-2 3.9 7.1 x 103 , 1.52 x 10"j I.67 x 10"*

9.3 x IO3

8.8 x 10* 8.3 x 10 1.55 x 10

7.5 x IO"8 1.26 x 10"1

Surface Activity 24 hours

After Meltdown dis/cm2 sec

1.08 x 10-1 1.62 x IO"2

4.0 x 10'

2.4 2.0 x IO4 2.7 x 105 5.9 x 105 5.9 x 10\ I.65 x 10, 1.92 x IO4 3.7 x 107 7-9 -1 8.7 x 10

4.1 x IO 7

4.0 x 10° 3.8 x IO4 7.0 x IO 4

Oi

TABLE I (continued)

Kb =89 Kb=90 Kb =91 Kb~92

Cs-134 Cs~136 Cs=137 Cs=138 Cs-139 Cs=l40

Sr=89 Sr=90 Sr-91 Sr-92 Sr=93 Sr~94

Ba=137m Ba-139 Ba=l40 Ba-l4l Ba=l42 Ba-l43

Half-Life

15.4m 2.74m l4 m 80s

2.0y 13d 26.6y 32m 9,5m 66s

54d 28y 9.7h 2,7h 7m 20m

2.60m 85m 12,80d 18m 6m 30s

Core Content After 10 Days

Operation, Atoms

1.96 x IO 2 0 4.3 x 10 1 Q 1,46 x IO 2 0 1.97 x 1010

1,32 x IO18 1,34 x 102° 1,56 x IO23 4.8 x 102° 1,48 x IO20 1,79 x 101Q

1.25 x IO23 1.54 x 10^ 9.2 x 10|1 2,7 x lO^1 1.20 X 10^u 3.2 x lO1^ 2.9 x 10l6 1.39 x IO21 1.32 x IO23 2.9 x 102° 8.9 x 101Q 6.6 x IO18

Isotope in Coolant System After Meltdown

Atoms 1.96 x 10J7 4.3 x IO 1 6 1.46 x IO1? 1.97 x IO16

1.32 x IO1?" 1.34 x 10JJ 1.56 x IO 2 0 4.8 x IO1? 1.48 x IO1] 1,79 x IO16

1,25 x IO20 1.54 x IO20 9.2 x lOlg 2.7 x 10ia 1.20 x IO1' 3.2 x IO16

2.9 x IO13 1.39 x IO18 1.32 x IO20 2.9 x IO1! 8,9 x 1010 6.6 x IO1?

Coolant Activity Immediately

After Meltdown dis/ml sec

1.30 x 106 1.60 x 10° 1.06 x 10° 1.50 x IO6

1.28 x 10=1 7.3 x IO2 1.14 x 10-* 1.53 x 10° 1.59 x 10° 1.66 x 10° 3.2 x IO3 2.1 x 10, 3.2 x IO4 3.3 x IO4 3.4 x IO4 3.2 x IO11

2.2 x 10 3.3 x IO4. 1.43 x lp4 3.2 x IO4 3.0 x IO4 2.6 x IO4

Surface Activity Coolant Activity Immediately 24 hours

After Meltdown After Meltdown dis/cm2 sec dis/ml sec

105 103

5.5 x IO6. ,8 -9

x 10° x 10°

5.5 x 10° 3.9 5.7 2,5

IO3 10" 10( ,6

5.6 x 10^

-10 6.0 x 10' 3.1 x 10" 7.1 x 10=

2.2 x 103 1.45 x 10 3.9 x IO3 4.8 x 10

1.25 x IO"2 1.04 x 10 9.3 x 103

Surface Activity 24 hours

After Meltdown dis/cm sec

3-7 x 10? 2.4 x 103 6.5 x 105 8.2 x 103

2.1 1.73 x 10-1.57 x 10̂ -

5.1 4.6

x 10^ x 10e

7-

Removal_of_Fission_Products_fro^^

The active fission products released into the HFIR primary coolant system upon the meltdown of the fuel are removed by either decay or by the cleanup system. The cleanup system has provisions for removing the dissolved materials from the coolant water.

For the purposes of calculations^ it is assumed that the isotopes deposited on the cooling system walls are in equilibrium with the cooling water at all times. Also it is assumed that the cleanup system removes all of the fission products from the water passing through it. A material balance may be written for the first number of a fission product decay chain as follows:

dN. dN. — i £ + — l i = _ X.N, - \-.N. - BN. dt dt 1 iw x 1 S l w

where

N, = quantity of isotope |.n the water

N. = quantity of isotope on the coolant system surfaces

A,. = decay constant , ,_ (flow rate to the cleanup system) 8 = cleanup constant = ■ * -■■ .—, — — — \ * -(volume of system)

t = time

Letting,

N _ is _ atoms of isotope on cooling system surfaces i N. ~ atoms of isotope in cooling system water iw

therefore,

dN. dN. f is _ iw dt ~ i dt

8.

and

dN. iw , „ ,. = - U.N. dt 1 iw

where

U. = X. + i , g l i 1 + 6,

Writing a similar material balance for the second member of a fission product decay chain,

dN,, dt w + Aitlis = ̂ + ̂ _ A. + 1N (. f l ) w - X i + 1N (. + 1 ) s - BN ( i + 1 ) w

Letting,

R _ (i+1)s i+l N,. ... ' (i+l)w

therefore,

(i+l)s _ (H-l)w dt " ~ i+l dt '

and

dN dt l iw l+l (i+l)w

where

1 + 8c . i i - .

1 1 + 6 . , , 1 1+1

U , , i = X , + ^ - 4 i+ l i + l 1 + 8 i + l

Solving these equations for N. and N,. 1X , ° iw (i+l)w

N . = N ? . e * iw iw

- U . , n t e .N . XT *T 0 1 + 1 1 1W N , , , n = N , , . . e + —

( i + l ) w ( i + l ) w u L - [1±

- ^ t -u i + 1 t e - e

where

N. = N. immediately after the meltdown iw iw J

N,. ,. = N.. 1S immediately after the meltdown (i+l)w (i+l)w J

t = time after meltdown

The removal of most of the isotopes released during the meltdown of the fuel from the primary coolant system can be represented by the above equations. However, there are some specific cases where the released isotope must be considered as a third or a higher number member of a decay chain. Specific decay chains considered for these special cases are as follows:

10.

131m 131m

133m

6s 1 3 3 (stable)

I13^ 30y° » Xe 1 3 5 m Cs 1 3 5 (half-life = 3.0 x 10 yrs

Ba 137m

4 " ^ Ba 1 3 7 (stable)

Xe 139 -**- Cs 139 Ba 1 3 9 «-r La 1 3 9 (stable)

Material balances in the form of differential equations similar to those shown above can be written for each member in the above chains. These equations then can be solved for the quantity of each isotope in the system by the use of Laplace transformation methods.

11.

The cleanup bypass stream flow rate is 400 gpm which gives a value of the cleanup constant B Of'i400/30,000.or 0.0133 min"1. Using this value and the above relations, the concentrations of the fission product activities in the water and on the surfaces 24 hours after the meltdown were calculated. These values are shown in Table I.

Gamma_Sources_in_Coolant_System

The number and energy of gamma photons given off from the disintegrating isotopes are given by Blomeke and Todd.3 For convenience, the photons are listed in four energy ranges.3 Table II shows the gamma sources in the HFIR primary coolant system immediately following the meltdown of the fuel element. Table III shows the gamma sources in the coolant system 24 hours after the meltdown.

Discussion Many assumptions were made in obtaining the coolant system activity following the meltdown of the HFIR fuel. In particular, the values used for the amount of fission products deposited on the coolant system surfaces are a very rough estimate based on some semi-quantitative data^obtained by Edwards, et al.°. It was assumed that the deposition of fission products on the coolant system is uniform which probably is not actually true. The system volume to surface ratio was ignored in considering the wall deposition. Also particles of uranium oxide which contain fission products may be suspended in the water following the meltdown. These were ignored in these computations.

Inspection of Tables II and III shows that the halogens and the rare gases constribute to most of the gamma activity in the coolant system. After 24 hours, iodine appears to be the major source of activity. This occurs because iodine and its precursor, tellurium, are very readily deposited on the coolant system surfaces. These results appear to be consistent with the data obtained at the Westinghouse Testing Reactor during the period following the meltdown of a fuel element in this reactor. Binford peeled the decay curves of the WTR head tank activitylO and obtained depay constants approximately equal to those of il^ , Br^4^ an(i Kr°°. These isotopes also appear to a major source of activity in the HFIR coolant following the meltdown of the fuel in the reactor.

Conclusions

An estimate has been made of the fission product activity in the HFIR primary coolant system immediately following and 24 hours following the melting of the fuel within the reactor. Many assumptions were made in making this estimate, particularly the one regarding the amount of isotopes adsorbed on the cooling

12.

system surfaces. The rare gases and the halogens appear to be the main contribution to the gamma activity in the coolant system immediately after the meltdown, and iodine appears to be the main contribution ̂ ihburs after the meltdown. These results seem to be consistent with the data obtained at the Westinghouse Testing Reactor following the fuel element meltdown in that reactor.

Bibliography

1. G. E. Creek, W. J. Martin, and G. W. Parker, Experiments on the Release of Fission Products from Molten Reactor Fuels, 0RNL-2616 (July 7, 1959).

2. T. E. Cole, HFIR — Release of Fission Products from Meltdown of the Core, Memo to HFIR File (Feb. 15, I960).

3. J. 0. Blomeke and M. F„ Todd, Uranium-235 Fission-Product Production as a Function of Thermal Neutron Flux, Irradiation, Time, and Decay Time, ORNL-2127 (Aug. 19, 1957).

4. R. D. Cheverton, Personal Communication (Dec. 1959).

5. J. C. Mailen, Reactor Coolant Decontamination; A Literature Survey, ORNL CF-59-10-124 (Oct. 30, 1959).

6. M„ P. Edwards, et al, The Behavior of Fission Products in Circulating Pressurized Water, AERE-R3047 (AuigV-r9:59~)~—--.

7. J. C. Griess, Personal Communication (Mar. I960).

8. R. E, Schappe'l, Personal Communication (Apr. I960).

9. F. T. Binford, Personal Communication (Apr. I960).

10„ He A. McLain, Trip Report to the Westinghouse Testing Reactor, April 18, -I960, ORNL CF-6O-4-IO7 (Apr„ 27, I960).

' ^ ^ W l t ^ L ^ cuJL Tut Hifu^

Table II Gamma Sources in the HFIR Primary Coolant System

Immediately after Meltdown JO.

Isotope

_..___ Kr-83m Kr-85m Kr-85 Kr-87 Kr-88 Kr-89 Kr-90 Kr-92

Xe-131m Xe-133M Xe-133 Xe-135m Xe-135 Xe-137 Xe-138 Xe-139 Xe-140

Br-82 Br-83 Br-84 Br-85 Br-87 Br-88

1-130 1-131 1-132 1-133 1-134 1-135 1-136 1-138 1-139

Group I E < 0.25 Mev photons sec ml

2.6 x 10S 3.2 x IO8

5.0 x 108

1.5 x 106 3.8 x 107 1.2 x 109

3.6 x 107

4 4.3 x 10H

1.4 x IO5

Coolant Group II

'0.26, 1.71 Mev photons sec ml

1.9 x IO8 6.9 x IO8

i 1 ! !

5.2 x 104

2.2 x 105

2.5 x 104

2.5 x lof 2.8 x IO5

Surface Group I

E ̂ 0.25 Mev photons

2 sec cm

4.5 x 107

1.5 x IO8

Group II .0.26 ̂ E ̂ ,1.00 Mev

photons 2 sec cm

1.2 x 104

1.6 x IO8

1.4 x IO8 8.4 x 10° 6.1 x IO8 3.2 x 107

Group III 1.01

Table I I contd 14.

Isotope

Se-77m Se-79m Se~79 ' Se-81tp Se-81 Se-83 Se-84

Mo-99 Mo-101 Mo-102

Te-125m Te-127m Te-127 Te-129m Te-129 Te-131m Te-131 Te-132 Te-133m Te-134 Te-135

Tc-99m Tc-101 Tc-102 Tc-107

Ru-103 Ru-105 Ru-106 Ru-IO7

Coolant Group I

E , I.7I Mev photons sec ml

Surface Group I

E < 0.25 Mev photons

2 sec cm 1.7 x 103 1.4 x 105

8.8 x 104

3.4 x 106

4.8 x 107 4.7 x 107

2.5 k 2.2 x 10

6.2 x 105

4.3 x 10^ 2.8 x 10J 3-7 x 10'

5.4 x 106

Group II 0.26 4 E < 1.00 MevC

photons 2 sec cm 111

3.4 x IO8

5.3 x 106 3-3 x 103

1.4 x IO7

1.3 x 10^

5.8 x IO7

4.7 x IO7

3-9 x 10* 8.2 x 10

Group III "K01 ̂ E.^ L7O Mev'

photons 2 sec cm

Group IV E ̂ 1.71 Mev photons e„„ „ 2 sec cm

Table I I contd 15.

j Isotope

Rb-86 Rb-88 Rb-89 Rb-90 Rb-91

jRb-92

; c s - i 34 : ,Cs-l36 ;Cs-i37 •Cs-138 !Cs-139 Cs-l40

Sr-89 Sr-90

.Sr-91 :Sr-92 '■Sr-93 Sr-94

Ba-137m Ba-139 Ba-l40 B a - l 4 l Ba-l42 Ba-l43

Tota l

2 .2 x 10 1.6 x 10 4

2.4 ioJ

Coolant

E < 0„25 Mev photons sec ml

0o26 ^ E

Table III 16. Gamma Sources in the HFIR Primary Coolant System

24 hours after Meltdown

1

Isotope

iKr-83m !Kr-85m 'Kr-85 Kr-87 Kr-88

Xe-131m Xe-133m Xe-133 Xe-135m Xe-135 Xe-137

Br-82 'Br-83 Br-84

1-130 1-131 1-132 1-133 1-134 1-135 1-136

Se-79 Se-81m

Mo-99

Coolant Group I

E

Table I I I contd 17.

Isotope

Te-125 Te-127m Te-127 Te-129m Te-129 Te-131m Te-131 Te-132 Te-133m Te-134

Tc-99m

Rb-86 I Rb-88

,Cs-134 Cs-136 Cs-137

Sr-89 Sr-90 Sr-91 Sr-92

Ba-137m Ba-139 Ba-l40

Total

Group I E < 0.25 Mev photons sec ml

-4 4.7 x 10 * 4.0

1.1 x IO2

3.2 3.9 7.1 x 103

1

9.3 x 103

6-9 h 1.0 x 10

1.8 x 106

Cool Group II

0,26. I.7I Mev photons sec ml

2.8 x 10"2

4 2.5 x 10

Group I E

18.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23-24. 25. 26. 27-28. 29.

30-34. 35-36. 37-u8.

h9'. 50-51-

52. 53-6?.

Distribution

E. G. R. B. C. A.

tT. G. R. D. H. C. T. E. C. W. J. A. E. P. W. R. W. R. J. P. L. A. N. Hi P. R. J. A. M. I. R. N. H. A. J. R. R. L. L. C. R. C. R. E. R. S.

Bohlmann Briggs Burchsted Chapman Cheverton Claiborne Cole Collins Cox Epler Gall Gambill Griess Haack lvety Kasten Lane Lundin Lyon McLain McWherter Moore Oakes Robertson Schappel Stone

A. Taboada M. Tobias D. R. C. E. REED

Vondy Winters Library

Laboratory Records Document Reference Section Central Research Library 'M. J. TISE,

Skinner AEG