SUSNRDL-TR-631

Cr-ý 13 March 1963

( /[ FRACTIONATION II.ON DEFINING THE SURFACE DENSITY OF CONTAMINATION

-- ... E. C. Freiling

Qz"? S. C. Rainey

SU.S. NAVAL RADIOLOGICALqamDEFENSE LABORATORYS~ A N F RE NCI S C 0 2 4 C A L I O R N Y

SAN FRANCISCO 24, CAL FORNPIA

12ND. P7463

PHYSICAL CHEMISTRY BRANCHE. C. Freiling, Head

CHEMICAL TECHNOLOGY DIVISIONL. H. Gevantman, Head

ADMINISTRATIVE wIOFOMATION

The work reported was requested specifically bythe Fallout Studies Branch, Division of Biology andMedicine, U. S. Atomic Energy Commission. Itis part of a project sponsored under AEC ContractNumber AT(49-7)-1963. The project is describedin USNRDL Technical Pro&[am Summary for Fiscal iYears 1963, 1964, and 1965, 1 November 1962.It is designated as Problem 7, Program A-1.

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

E9e&. P. Cooper E.g. Roth, CAPT USNScientific Director Commandinwg Officer and Direc'tor

ABSTRACT

This report precents a technical basis for defining surface

density of fallout cnUtamination when the contaminating debris is

fractionated. Specifically, it recommends that the exposure dose

rate from fractionnted debris be expressed as a contamination surface

density multiplied by the sum of three terms. The first term is the

exposure dose rate contribution of refractorily behaving fission-

product nuclides per unit contamination surface density. The second

term is a similar quantity for volatilely behaving fission-product

nuclides. The third term expresses the contribution of the induced

activities.

i

PREFACE

This series of reports presents and discusses the effects of

radionuclide fractionation in nuclear-bomb debris. The first part

(Reference 1) defined fractionation as "any alteration of radionuclide

composition occurring between the time of detonation and the time of

radiochemical analysis which causes the debris sample to be non-

representative of the detonation products taken as a whole." It showed

how the radionuclide compositions of fractionated samples could be

correlated empirically by logarithmic relations. The present part

uses these relations as the basis of a technical discussion of contami-

nation density as applied to fractionated nuclear debris. The third

part will present a theoretical foundation for the observed logarithmic

correlationz of Part I. It will use this as a simplified means of

estimating fractionation as a function of particle size and the par-

tition of product radionuclides among local, intermediate, and world-

wide fallout. The fourth part will extend the calculations to show

how fractionation-correlation parameters can be used to estimate the

exposure dose rate from nuclear debris with various degrees of frac-

tionation. It will serve to illustrate the proposals made in the

present part.

DN1UWCTION

Those engaged in the study of fallout contamination from nuclear

debris frequently express the surface density of contamination in

terms of "kiloton-equivalents of debris per square mile." This term

is particularly useful in discussing exposure dose rate, and when

applied to unfractionated debris (1) it is easily defined with

precision (2). However, the presence of unfractionated nuclear debris

is the exception rather than the rule, and the concept of "kiloton-

equivalent of debris" becomes undefined when the debris is fractionated.

That this is so becomes evident when one considers that "kiloton-

equivalent of debris" is actually a variation of the concept, "frac-

tion of the device." As explained in Reference 1, "fraction of the

device" becomes undefined in the presence of fractionation. It is best

replaced with the fraction of some component of the debris, either of

some residual, pre-shot material or of some product of the nuclear

processes which occurred. Because of fractionation, the fraction of

one component per unit area at a given location will not necessarily

equal the fraction of any other. The difficulty is overcome by choos-

ing one component as a reference and relating the abundance of the

other components to it.

2

The purpose of this report is to present the technical back-

ground for modifying the "kiloton-equivalent of debris" concept for

fractionated fallout and to define the modified concept in simple terms.

The material will be presented from the viewpoint of exposure dose

rate. Since the "kiloton-equivalent" is, by definition, 1012 calories

or a "teraca.lorie", we will use.. the latter term throughout the re-

mainder of this report.

TECThNICAL DISCUSSION

Besic Considerations

The radiological hazard from a deposit of fallout is generally.,

expressed as exposure dose rate (D) and arises from the photons pro-

duced by radioactive decay and by various interactions of the radia-

tion with matter. The radionuclides responsible are predoninantly

beta-Gers a emitters. The beta particles can interact with nuclei

to form photons known as Bremestrablen, but these contribute only a

few percent to the total dose rate and will not be considered furthcr.

The gmim.-photons nay be internally converted to characteristic X r'.y,

or they rmy interact with environmental material by elastic scattering,

photoelectric effect, Compton scattering, or pair production. ,legarc-

less of cubceciuent alterations, the primary emissions of radiological

significance are the gomme photons and characteristic X rays, which

are energetically discrete and virtually independent of the environment.

3

Their relation to activity, spectra, and exposure dose rate can be

described as follows. The terminology, symbols and units used are

summarized at the end of the discussion.

Consider a homogeneous source of Nj atoms of type j disintegrating

according to the radioactive decay law

A - -N N W

where A is the disintegration rate (activity) and X is the total

radioactive decay constant. The photons emitted will have discrete

energies (Ei). An average of Nij photons with energy Ei will be

produced per disintegration. The (total) photon emission rate for

these atoms is A r N and the rate of energy emission in the forma i ijof photons is A Z Nij Ei. The distribution as a function of energy

of the fraction o2 the total number of photons emitted which fall into

each energy group is called the photon spectrum.

Now consider the source material as a contaminant distributed

over a soil-air interface. The quantity of radioactive material of

type j per unit area at any location on the interface is the surface

density of contamination (a ) at that location. The exposure dose

rate sensed by a detector at any point in this system will be due to

the photon spectrum at that point and this will differ from the primary

spectrum in several ways: it will no longer be discrete, it will be

degraded in energy, and will depend upon both the environment and the

source-detector geometry. Each photon in this secondary spectr=u will

produce a contribution to the dose which will depend upon its energy.

4i

The calculation of dose rate from the nature of the source and

from the source-detector arrangmnt for even one type of nulide is

very complicated and requires the Introduction of several reasonable

simplifications.

Calculation of Exposure Dose Pte From a Homogeneous. Distributed

Source Composed of a Single Nuclide.

A reasonably accurate simplifying device for calculating exposure

doee rate from a distributed source is found in the dose-rate con-

version factor. Assume that the homogeneous contaxmiat is distributed

on the interface so that the contamination density varies gradul~y

with location and., as far as any given detector position Is concerned.,

may be considered everywhere equal to the contamination density a

at the closest point of the interface. Primary photons of energy Z1

now produce a contribution to the dose rate Di which is proport ioal

to the photon emission rate and therefore to a X. The proportionality

factor (di) is a function of the enerS7 and will be called the photon

dome-rate conversion factor for the given arrangement.

Dim- di N1 3 ajX (2)

A nuclide dose-rate conversion factor (d t) is defined similar3y in

term of the total dose rate (D3 ) from all nuclides of type J.

Whereas Di in proportional to the photon emission rate per unit area,

D will be proportional to the disintegation rate per unit area:

5

D 0 aX E di a di ()

Therefore

dj a E di Nij (14)

To illustrate dose-rate calculations for fallout, it is customary to

specify the following standard set of conditions: the detector in

located 3 feet in air above an infinite, smooth, uniformly contami-

nated plane of unspecified soil material which is impenetrable to the

radioactive fallout; the time is 1 hour after detonation with refer-

ence to radioactive decay, but is an infinite time after detonation

with reference to the amount of material fallen out. An asterisk will

be used to indicate dose rates and dose-rate conversion factors for

standard conditions. Thus

* * c =a *D d a d= d N (5)a a a a a i i ij

Extension to Homogeneous, Representative Sources Composed of a Single

Mass Chain.

As mentioned earlier, the radiologically important radionuclides

produced in nuclear detonations are predominantly beta-gamma emitters,

although some neutron emission occurs at early times. Since the

nuclidic mass does not change in beta-gamma, emission, fission products

and induced activities group into isobaric chains , each with a con-

stant total nvmber of atoms. Although some 90 mass chains result from

fission, only a few of these contribute significantly to the dose rate

at any given time. They can be treated as follows.

*Nuclides with equal mass numbers but different nuclear charge are6alled isobars.

6

Let Yk be the average number of fission-product or induced atoms

of mass k produced per fission. Then the fraction of atoms with mass

k which exist as type j at any given time is a perfectly definite

quantity which we will call Gjk(t). The number of atoms of type j

per fission existing at any time is YkGjk(t). If a total number of

fissions F has occurred, the total number of J-type atoms present at

time t is FYkGjk(t). Let us represent the number of atoms of mass

chain k per unit area by akYk. The number of atoms of type j per

unit area is now a, = ak YkGjk(t). Here ak is the number of fissions

which produced the quantity of chain k present per unit area at the

location considered. Now the total contribution of the kth chain to

the dose rate (Dk is obviously the sum of the contributions of the

individual members.

Dk E D

jJ

makYk i dJjkdj (t) X (6)

The quantity d Gjk(t) X is the dose rate contribution from isobar

j per atom of chain k at time t. Its sum over j is the dose rate

contribution of the k chain per atom of mass k per unit area. It will

be convenient to designate this sum 15k(t) and write

D -k = k (t) (7)

7

The total contribution from all chains in

k kM T ak Bk "k (t) (8)

k kk

If the debris is representative, all akIs are equal and we can write

D E Yk Dk (t). (9)kh

Fractionated Debris

The above formulas can reflect fractionation in two different

vays. The first is by requiring a different value of a for each mass

chain. The second is by requiring a factor for each nuclide to correct

Yk" .The second way reflects the fractionation of isobars from one

another. It is predominant in the early stages, when debris is formed,

and is responsible for much of the fractionation observed. For example,

the fractionation of Xe O and CsllfO from B 140 produces the volatile

behavior observed for the uass-140 chain. However, subsequent growth

and decay convert this intrachain fractionation into intercbain frac-

tionation, so that by one hour after detonation we are Justified in

neglecting intrachain fractionation and concentrating on the variation

of ck.

The variations in ak are most easily handled by taking one mass

chain as a reference and relating ak for all other mass chains to

that for the reference chain. Now in any nuclear event, a large nuber

of mass chains do not fractionate from the mass-95 chain. Abundant

8

date exist for the mss-95 cbsin composition in fallout from previous

nuclear tests. It is one of the most refractorily behaving mass chains

and one least subject to secondary fractionation. It has a high and

relatively constant fission yield which can be determined in two in-

dependent ways by analyzing for either Zr5 or Nb95. The half lives

of these nuclides are such that they can be determined long after

fission. For these reasons the mass-95 chain is chosen as the primary

reference chain. Then 095 becomes the measure of contamination density.

It is the number of mss-95 chain equivalent fissions (i.e., the number

of fissions required to produce the number of nsss-95 atoms found) per

unit area at a given location.

The fractionation of other chains can be expressed by ratios of

the type

rk, 95 m Ok/095 (10)

The total dose can now be written

D = a95 1 Yk rk, 9 5 Dk (t) (11)

Empirical correlations of fractionated debris (1) and theoretical

considerations (3) both lead to relations among the ratios of the type

10910 r k, k + b) 1 (12)

Here r ,95* is the fractionation ratio and is a measure of the degree

*The fractionatio ratio r89 ,9 ~ is the ratio of the number of fissionsrequired to produce the amounz of the mass-89 chain found in a sampleto the number of fissions which votld be required to produce the amountof the nmss-95 chain found In the same sample.

9

of fractionation at the location of interest. fo qutantities ak and

bk are soplrioal2y determnined by the Intercept and slope of a log-log

p rk, . 1/8,9 The qu.antity ak can btheotiQc

determined from bk if the paticle-else distribution is known (4). FM

dose-rate calcu~ationsi its departure from sero can be neglected vhen

the particle site distribution is unknown, and ve can vrite the above

in a more convenient, approzlmate form

'k, 95 ' (89,95) k(33)

For Important contributors to the radiological field, the quantity bk

Is almost alvays between 0 and 1 in value and its imgnitude can be

estimted by an empirical r.le (1). ftmtion (ii) can then be written

1 - b

Du =a95 E Yk (r89.,95) Dk (t) (Ak)

The various mass camins can be d.ivided into three groups. The

first group consists of those sass chains which do not fractionate

significant27 from the sos-95 chain. Examples are the sass 99, 103,

106, and 1i4i through 161 fission-product chains and the activities

induced in the weapon components. For these refractori3y behlving

chains, bkp 1 and their contribution to the dose rate is

DR "95 EYk k (t). (15)

quasi-refractorychains

10

The other fission-product sass chains will exhibit values of bk

which depart appreciably from unity. In local fallout, they vwil be

depleted relative to the mass-95 chain. The contribution of these

volatilely behaving chains can be written

D~ a-95 E (r8 9 ,9 ) k k JDk (t). (16)quasi-volatile

chains

Finally., since they do not have gaseous precursors, and have shown

no evidence of volatile behavior, the induced activities can be assemed

not to fractionate from the refractorily behaving activities (i.e., Ok

can be assumed equal to 095). The induced activity chains can also be

considered to have yields Yk' the yield of the kth chain being simly

the ratio of the number of atoms of that chain produced by the detona-

tion to the total number of fissions in the detonation. (The value,

however, is not easily established with certainty.) Thus we can write

their contribution as

P . 095 E Yk b k (t) (17I)induced

chains

The total exposure dose rate can now be written

D (t) a 9 5[1E Yk k(t) + E Yk rN9,95 ) k Ik(t) + EYk Dk (t)] 1)

quasi-refractory quasi-volatile inducedchains chains chains

l1

This equation says that the exposure dose rate from fractionated

debris can be expressed as a contamination surface density multiplied

by the su of three terms. The first is the exposure dose rate contri-

bution of the refractorily behaving fission-product elements per unit

contamination surface density. The second term is a similar quantity

for the volatilely behaving fission product radionuclides. The third

term expresses the contribution of the induced activities. For

standard conditions the expression is

D*' k +Yk (r89 ,95) k Z k~] (v

Units

This section lists the primary quantities of interest in the

preceding discussion, together with their designations, and a recom-

mended system of units for consistent use of the equations. Care has

been taken to avoid the use of cumbersome units such as "curies" and

"gamma curies".

Symbol Physical Quantity Unite

D (Di, Djp Dk, DR, exposure dose rate roentgens per

DV DI) second

A disintegration rate disintegrations

per second

N number of atoms atoms

* Although the term "chain" is usedp most induced activities decay to

stable nuclides in one step.

12

Sphotcs per Oislategm- photons per dis-tion Inteiation

decay oonstant per second

I I d.4 VeT

a (0, Ok) cotmnto $1rac j sois e =density ok issions per as2

a 1 just as the eombined quantity N. (atow sHec")

in cimnly given the vnit disintepations

per secondL' so the combined qLantity OX

(ato •-2 see-l) bas the Vnit wdimntegpa-

tions se"1 =72.w

d (dis djo Dk (t)) dose rate conversion dk roentgens per

factors (photon/c 2 )

d roentgens per

S(disintegration/cm)

bk(t) (roentgenh/sec),per(atcsi/cm.)

Y total chain yield atoms per flission

G chain fraction dimansionless

r fractionation factor dimensionless

SIMPLE=IF I' P1 N3 fCN

To most effectively dispel isimderstandings about fractionation

and its effoct on dose rates reqires that a tecniLcal exposition of

the OcP1zldties Involved be s nted i diasenination of the infor-

mation.

13

The following presentation attempts to achieve maxiim simplicity

for the general user of such informtion with the minimum loss of rigor.

In this presentation we first recommend use of the following

alternative system of units for large scale considerations. They are

obtained from those in the previous paragraph by simply substituting

teracalorie for fission and square mile for square centimeter. The

only quantities affected, together with their alternate units, are

the following

o teracalorie per square mile

d (roentgens/photon) per ýeracalorie/square mile)

Y. atoms per teracalorie

If these substitutions are made in the treatment, Equation 19 would

still apply, as in the detailed discussion. Again, the units of curies

and of gama curies have been successfully avoided.

With these minor modifications, the considerations of the fore-

going section can be simuarized for a scientific (but non-specialized)

audience as follows:

If, at any time after detonation, all the debris from

a nuclear burst of W teracalories fission yield were uniformly

spread over W square miles, the resulting dose rate three feet

above the plane at one hour can be shown to be of the order of a

roentgen per second. In this situation each radionuclide is said

to be present at the !. contamination surface density of "one

teracalorie equivalent of that nuclide per square mile"

for the burst in question, even though the quantities of

these radionuclides vould differ from nuclide to nuclide

by orders of magnitude when expressed in term of atom

or disintegrations per second. In a real deposit of

debris, say from a land-surface burst, the debris vill be

fractionated, and the individual radionuclides wll be

present at diffarnt "teracalorie equivalents" per square

mile. However, even here a large fraction of the fission-

product nuclides will be present at any location in nearly

the saw nusber a of teracalories per square mile. One of

these nuclides is Zr 9 5 , which we will use for a reference

nuclide, and so we will designate this value of a by '95.

In addition, the activities induced in the weapon com-

ponents and the soil can be considered to be present at

the same number a 95 of teracalorie equivalents per square

mile. Other nuclides will have contamination surface

densities that depart significantly frm a95. For the most

part, these will be fission products, and in local fallout

their contamination surface densities vill be less than 095.

One of tbese, Oro, will be taken as a reference of such

volatile behavior. Its contamination Mrface density at

anY point, `S9P can then be used to define the degme of

fractionation 0 at any point.

15

O slo (UB/119,) (20)It has been found that nuclides of sass chain k have con-

tamInation levels related to a, by xessions such as

10 O.5 10910 095 + Ck 0 (21)

where Ck is a constant depending on k. The values of aW

089 and 0 will all vary from point to point in the fallout

pattern, but at any point their values vill rinin essen-

tially constant vith time if the pattern is not disturbed.

Once the values of Ck are established for each mass chain

of interest7 the resulting exposure dose rate can be ex-

pressed, even for fractionated fallout contaminant, by

saJng the contributions to the exposure dose rate from

all the contributors.

Finally, the adoption of this definition of contamination level

should do much to clarify the effects of fractionation on dose rates

from fallout, to obviate false conclusions arising from a misunder-

standing of fractionation effects, and to provide a sound foundation

for the treatment of associated problems.

1. E. C. Freiling. Fractionation I. High Yield Surface Burst

Correlations. U. S. Nval Radiological Defense laboratory

Technical Report, U=MIHD-TR-385, 29 October 1959. Science,

M~: 1991 (1961).

2. "The Effects of Nuclear Weapons, "Revised edition, U. S. Atomic

Energy Ccission, Washington, D. C., 1962.

3. Theoretical Basi for Logritbmic Correlations of Fractionated

Radionuclide Compositions. E. C. Freiling. Science, M:1058 (1963).

4. E. C. Freiling. Fractionation III. Esitimaton of the Degree of

Fractiontion and Radionuclide Partition for Fractionated Nuclear

Debris. U. S. Naval Radiological Defense laboratory Technical

Report, to be published.

17

INITIAL D -flTI- I X

3 Chiefs Bureau of Mips (Code 335)1 Chief, Bureau of Ships (Code 320)1 Chief, Bureau of Medicine and Surgery1 Chief, Bureau of Naval meapems (NRNL-ll)2 Chief, Seau of Tards and Docks (Code 74)1 Chief, Bureau of lards and Docks (Code C-4,00)1 Chief of Naval Operations (0p-O7T)1 Chief of Naval Research (Code 104)1 Ccmnder, lw York Naval ShiWard (Material Lab.)3 Director, Naval Research Laboratory (Code 2021)2 Director, Naval Research Laboratory (Code 6370)1 Office of Naval Research (Code 422)6 Office of Naval Researeh, MO) New rork1 CO U.S. Naval Civil Engineering Laboratory1 Cosmader, Naval Air Material Center, Philadelphia1 Naval Medical Research Institute1 U.S. Naval Postgraduate School, Monterey1 Office of Patent Coimeel, San Diego1 U.S. Naval Hospital, San Diego

1 Chief of Research and Development (Atomic Div.)1 Chief of Research and Development (Life Science Div.)1 Deputy Chief of Staff for Military Operations (CDR)1 Chief of Engineers (RK(C-D)1 Chief of Engineers (IN1 Chief of egineers (UIOCW)1 MG AraW Materiel Coinand (ANCRD-DE-NI)1 0G, Ballistic Research Laboratories1 CG USA OR Agency1 President, Chemical Corps Board1 COO Chemical Corps Traing Co(Jiand1 Comandant, Chemical Corps Schools (Library)1 00, CheOcal Research and Development LaboratoriesI Comander, Chemical Corps Nuclear Defense Laboratory

19

I Arq' Iviromontsl Ige Agency1 cO, Aberdeen Proving Gromod1 Director, e *.lter Ree AioW Medica Center1 0GC, Comat Developaunts Camnd(CDCU4V)1 Eq., Dogwmy Proving 0row3 The Surg.on General (iERM)1 CG, kgine.r Re@. and Dev. Laboratory1 Ifreeter, Offiee of Special Weapons DevelopmentI CO ArzW Research Office1 00, Watertown Arsenal1 cG, Nobility Comand1 CO, Munitions Comand1 CO, Fraukford Arsenal1 C0, Army Missile Commnd

AIR FORCE

1 Assistant Chief of Staff, Intelligence (AYC]N-3B)6 0,CG Aeronautical Syatems Division (ASAPRD-NS)1 Directorate of Civil Engineering (AFOCE-ES)1 Director, USAF Project RAND1 Commandant, School of Aerospace Medicine, Brooks AFB1 Office of the Surgeon (SUP3.1), Strategic Air Comand1 Office of the Surgeon General1 CG, Special Weapons Center, Kirtland AFB1 Director, Air University Library, Maxwell APB1 Comander, Technical Training IXng, 3415th TTG1 Coalnder, Electronic Systems Division (CRZT)

OTHER DOD ACTIVITIES

3 Chief, Defense Atomic Support Agency (Library)1 CoiAnder, FC/DASA, Sandia Base (FCDV)1 Commander, FC/DASA, Sandia Base (FCTG5, Library)1 Coimander, nC/DASA, Sandia Base (FCW?)2 Office of Civil Defense, Washington2 Civil Defense Unit, Army Library20 Armed Services Technical Information Agency1 Director, Armed Forces Radiobiolog Research Institute

ARO ACTIVITIES AND OTHES

1 Research Analysis Corporation100 Director, Division of Biology and Medicine1 Division of Biology and Medicine Fallout Branch (Knapp)1 Aerojet General, San Ramon1 Aerojet General, Asusa1 Allis-Chalmers Manufacturing Co., Milwaukee1 Allia-Chalmers Manufacturing Co., Washington1 Allison Division - (C32 Argome Cancer Research Hospital

20

Argonne National Laboratory1 Atomic Bo CaeualtCemkeseion

ABC Scientific Representative, FranceAMC Scientifio Representative, Japan

3 Atomic herg Commission, Vasbington4 Atomic bMere of Canada, Limited4 Atomic@ International2 Babcock and Wilcox Company2 Battelle Mamorial Institute1 Beryllim Corporation1 Borden Chemical Company4 Brookhaven National Laboratory1 Bureau of Nines, Albany1 Bureau of Nines, Salt Lake City1 Chance Vought Corporation1 Chicago Patent Group1 Colmbia University (Cropper)1 Combustion Engineering, Ine.1 Combuetion Rigineering, Inc. (NmD)1 Camittee ,on the Effects of Atomic Radiation1 Defence Research Member1 Denver Research Institute1 Division of Raw Materials, Washington1 Dow Chemical Company, Rocky Flats3 duPont Company, Aiken1 duPont Company, Vlmuington1 Edgerton, Germeshausen and Grier, Inc., Goleta1 Edgerton, Germeshausen and Grier, Inc., Las Vegas1 Fundamental Methods Association1 General Atomic Division2 General Dynamics, Fort Worth2 General Electric Company, Cincinnati4 General Electric Company, Richland1 General Electric Company, San JoseI General Electric Company, St. Petersburg1 General Scientific Corporation1 General Telephone and Electronic Laboratories, Inc.1 Goodyear Atomic Corporation1 Grand Junction Office1 Hughes Aircraft Company, Culver City1 Iowa State University1 Jet Propu lion Laboratory2 Knolls Atomic Power Laboratory2 Los Alamos Scientific Laboratory (Library)1 Nallinckrodt Chemical Works1 Maritime AdministrationI Martin-Marietta Corporation1 Massachusetts Institute of Technology1 Monsanto Chemical Company1 Mound Laboratory1 NASA,, Lewis Research Center

21

2 NASA, Scientific and Technical Infomatio. faeility1 National Bureau of Standards (Libary)1 National Bureau of S=tsadz4 (Talor)I National Lead Company of Ohio1 Now Brunewick Area Office1 New Tork Operations Office1 Nuclear Materials and Iquipuent Corporation1 Nuclear Metals, Inc.1 Office of Assistant General Counmel for Patents4 Phillips Petroleum Company1 Power Reactor Development Compay4 Pratt and Whitney Aircraft Division1 Princeton University (Wlite)2 Public Health Service, Washington1 Public Health Service, Las Vegas1 Public Health Service, Montgomery1 Purdue University1 Radiation Applications, Inc.1 Sandia Corporation, Albuquerque1 Sandia Corporation, Livermore1 Teohnical Research Group1 Tracerlab, Inc., Richmond3 Union Carbide Nuclear Copny (ORGDP)4 Union Carbide Nuclear Company (ORNL)1 Union Carbide Nuclear Company (Paducah Plant)1 United Nuclear Corporation (NDA)1 U.S. Geological Survey, Denver1 U.S. Geological Survey, YAmelo Park1 U.S. Geological Survey, Naval Weapons Plant1 U.S. Geological Survey, Washington1 U.S. Geological Survey, UK Division2 University of California Lawrence Radiation Lab., Berkeley2 University of California Lawrence Radiation Lab., Livermore1 University of California, Los Angeles1 University of Hawaii1 University of Puerto Rico1 University of Rochester (Atomic Energ Project)1 University of Utah1 University of Washington (Donaldson)2 Westinghouse Bettis Atomic Power Laboratory1 Westinghouse Electric Corporation (Rahily)1 Westinghouse Electric Corporation (NASA)1 Yankee Atomic Electric Company25 Technical Information Extension, Oak Ridge

UURDL

41 USRMDL, Technical Information Division

DMISR TOR DATE: 19 April 1963

22

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