DTRA / NTPR - Standard Operating Procedures Manual 

ID01 –Doses to Organs from Intake of Radioactive Materials 

Revision No.: 2.0 

Date: April 30, 2021 

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DEFENSE THREAT REDUCTION AGENCY

NUCLEAR TEST PERSONNEL REVIEW PROGRAM

RADIATION DOSE ASSESSMENT

STANDARD METHOD

ID01 – Doses to Organs from Intake of Radioactive Materials

Revision 2.0

Cleared for Release 

Key to SOP ID Codes 

RA (Radiation Assessment - SOP) 

ED (External Dose - Standard Methods) 

ID (Internal Dose - Standard Methods) 

UA (Uncertainty Analysis - Standard Methods)
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ID01 –Doses to Organs from Intake of Radioactive Materials

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Date: April 30, 2021

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Revision Control

Revision Revision Description Revision 

Date

Authorization 

Official

1.0 Original 10/31/2007 Paul K. Blake

1.1 - Section 5.2.1: Added a paragraph on the treatment of mission badges 

and related uncertainty.

- Section 5.3.2: Added a discussion about the daily rate of incidental 

ingestion of soil and dust. 

- Attachment 1: Added a new table for resuspension factors as Table 2 

(Resuspension factors for typical participant activities in contaminated 

areas).

- Attachment 1: Added the time-variable resuspension factor function 

for land-based exposures and related references. 

- Attachment 2: The “List of Surrogate Organs” is moved to this SM 

from RA01 and RA02. 

03/31/2008 Paul K. Blake

1.2 Editorial revisions to improve clarity of presentation. 10/31/2008 Paul K. Blake

1.3 - Section 5.2.1: Expanded section on resuspension factors to include 

probabilistic models.

- Section 5.2.2: Added section on blast-driven resuspension of fallout.

- Section 5.2.3: Expanded section on descending fallout to include 

probabilistic methods. 

- Section 5.2.4: Expanded section on neutron activation products.

- Attachment 1: Added table on model parameters, default values and 

distributions.

- Renamed Attachments 1 and 2 to Attachments 2 and 3.

- Updated References and made other editorial changes.

01/31/2010 Paul K. Blake

1.3a - Added the list of standard NTPR organs and tissues

- Moved Attachment 3 to Attachment 1.

03/31/2010 Paul K. Blake

2.0 - Added text in Section 5.2.1 explicitly stating the duration of 

exposure limit of 100 hours from inhalation of resuspended fallout 

deposited on the desk of ships and small boats. 

- Added new Section 5.2.1.1 and Table 2 to define, describe and 

provide values for GSMF.

- Revised Section 5.2.1.4 to clarify use of film badge readings to 

reconstruct internal doses for long-term exposures.

- Revised Section 5.2.2 to clarify that deterministic blast wave 

resuspension factors are upper bounds.

- Modified Section 5.2.3 to provide a discussion of inhalation of 

descending fallout for land-based and shipboard personnel and 

clarified use of a simplified deterministic equation.

- Revised Section 5.3.1 to clarify food ingestion scenarios impacted by 

descending fallout.

- Added resuspension factors to Attachment 3 for troops in 

helicopters, armored vehicles, and tank movements, personnel 

involved in decontaminating aircraft, and separate resuspension 

factors for support and target ships.

- Updated Attachment 1 for consistency with RA02.

- Updated Table A3-1 in Attachment 3 and added small transport 

boats. 

- Updated references and made other editorial changes as needed.

04/30/2021 James D. Franks
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Table of Contents

Table of Contents............................................................................................................................ 3

List of Tables .................................................................................................................................. 4

Purpose/Summary............................................................................................................... 5

Scope................................................................................................................................... 5

Responsibilities................................................................................................................... 5

Definitions........................................................................................................................... 5

Method Description ............................................................................................................ 6

5.1 Introduction............................................................................................................. 6

5.2 Inhalation Intakes.................................................................................................... 6

5.2.1. Inhalation of Fallout Resuspended from Surfaces...................................... 8

5.2.2. Inhalation of Blast-Driven Resuspended Fallout from Previous 

Depositions ............................................................................................... 13

5.2.3. Inhalation of Descending Fallout.............................................................. 16

5.2.4. Inhalation of Suspended Soil Activation Products ................................... 20

5.2.5. Inhalation in an Atmospheric Cloud ......................................................... 23

5.3 Ingestion Intakes................................................................................................... 24

5.3.1. Ingestion of Fallout Deposited on Food.................................................... 25

5.3.2. Incidental Ingestion of Contaminated Soil and Dust ................................ 26

5.4 Use of FIIDOS in Dose Reconstructions.............................................................. 28

Data and Input................................................................................................................... 30

Referenced SOPs and Standard Methods from this Manual............................................. 30

References......................................................................................................................... 30

Attachment 1. Cross Reference of Organs, Tissues, and Diseases for Internal Dose Assessment33

Attachment 2. Distributions and Deterministic Values of Model Parameters for Internal Dose 

Assessments...................................................................................................................... 37

Attachment 3. Resuspension Factors for Typical Participant Activities in Contaminated Areas 42
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List of Tables

Table 1. NTPR Standard Organs and Tissues used in Internal Dose Models................................ 7

Table 2. Average GSMF for Various Ship Types........................................................................ 11

Table 3. Breathing Rate Distributions by Activity Level for NTPR Test Participants................ 12

Table 4. Ratio of Intensity Due to Na-24 to Intensity Due to all Neutron Activation Products

[IR,Na(tm)]........................................................................................................................ 22

Table 5. Relative Surface Radioactivity of Neutron Activation Products to Na-24 Intensity, 

[SAi(0)]........................................................................................................................... 22

Table 6. Organ-Specific Inhalation DCF Bias Adjustment Factors, BF ..................................... 29

Table A1-1. Cross Reference of Diseased Organs, Tissues and Diseases and Corresponding 

NTPR Standard Organs*................................................................................................ 34

Table A2-1. Distributions and Deterministic Values for Model Parameters for Internal Dose 

Assessments................................................................................................................... 38

Table A3-1. Resuspension Factors for Typical Participant Activities in Contaminated Areas... 43
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Standard Method

ID01 – Doses to Organs from Intake of Radioactive Materials

Purpose/Summary

Standard Method (SM) ID01, Doses to Organs from Intake of Radioactive Materials, 

provides general technical and computational methods for assessing dose to internal 

organs and tissues from the ingestion and inhalation of radioactive materials (principally 

fallout) by nuclear test participants for the Nuclear Test Personnel Review (NTPR) 

Program. This standard method is used in support of the procedures specified in 

SOP RA01.

Scope

This standard method provides technical guidance for reconstructing internal organ doses 

due to alpha, beta, and gamma ionizing radiation as a result of the ingestion or inhalation 

of radioactive material produced during nuclear testing. This standard method is not to be 

used to estimate any external radiation doses such as to the skin or lens of the eye

because those dose assessments are addressed in other standard methods of this SOP

Manual. This standard method is used in conjunction with other standard methods for 

assessing radiation doses to organs and tissues from internally-deposited radionuclides in 

accordance with the requirements described in DoD (2020).

Responsibilities 

Qualified radiation dose analysis staff members use the methods described below for 

assessing the radiation doses for exposed individuals. If situations arise where these 

methods and techniques are inadequate to address a specific exposure scenario, it is the 

responsibility of the analyst encountering this deficiency to bring it to the attention of the 

RDA SOP Task Manager so that the methodology can be extended as required to provide 

adequate estimates of organ doses. It is the responsibility of the analyst executing and 

implementing this extension to document such extension in a revision to this standard 

method. 

Definitions

Aerodynamic diameter: The diameter of a sphere of density 1 g cm−3that exhibits the 

same settling velocity as the particle in question. 

Committed Equivalent Dose (50-year CED): The time integral of the equivalent dose rate 

over the time in years following the intake. The implied value for adults is 50 years, from 

age 20 to 70 years. (ICRP, 1990)
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Dose Conversion Factor (DCF): The ratio of 50-year CED to a tissue or organ to a unit 

film badge equivalent dose (rem) or curie intake of radioactive material given by the 

computer code FIIDOS (Fallout Inhalation and Ingestion Dose to Organs) and calculated 

using published specific dose coefficients for each radionuclide in the assumed inventory 

(Raine et al., 2007). 

Equivalent Dose: The product of the absorbed dose in an organ or tissue and a radiation 

weighting factor that accounts for the variation in the biological damage of the various 

types of radiation.

Internal Dose: In the NTPR program, “internal dose” means 50-year CED.

Method Description

5.1 Introduction

NTPR participants, whether at the Nevada Test Site (NTS), the Pacific Proving 

Ground (PPG) or in Japan, could have accrued internal doses as a result of intakes of 

radionuclides by inhalation, ingestion, or absorption through the skin or open wounds. 

Intakes by inhalation are the most common pathway for the majority of participants in 

atmospheric nuclear tests. Most exposure scenarios involve inhalation of descending 

fallout or fallout that was deposited on the ground or other surfaces and subsequently 

resuspended into the air. Additional pathways of internal exposure involve the

consumption of food or water that has been contaminated by fallout and the incidental 

ingestion of contaminated soil and dust. Absorption of radionuclides through the skin or 

an open wound is uncommon in exposures of atomic veterans and is not considered here. 

Unlike external doses, internal doses cannot be measured directly but must be estimated 

based on other available data and models. Because no relevant air monitoring data and 

very little bioassay data are available for atmospheric nuclear test participants, dose 

estimates are performed with indirect methods using internal dose models for 23 standard 

organs and tissues listed in Table 1 (Raine et al., 2007). These models use available data 

such as gamma intensity measurements in conjunction with various assumptions. For 

organs or tissues not listed, a surrogate organ or tissue should be selected from Table 1

using the guidelines provided in Attachment 1 (DNA, 1986). 

The values of the input parameters for the deterministic models and parameter 

distributions used in the probabilistically-based analyses are given in Attachment 2.

5.2 Inhalation Intakes

There are four basic pathways for the inhalation of radioactive material by nuclear test 

participants: 1) inhalation of fallout particles deposited on the ground or other surfaces 

and resuspended by mechanical or natural disturbances, 2) inhalation of radioactive 

material contained in descending fallout, 3) inhalation of neutron-induced radioactive 

material in the soil (or other material) lofted into the air by mechanical or natural 
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disturbances, and 4) inhalation of radioactive material in an atmospheric cloud (DNA,

1986).

Table 1. NTPR Standard Organs and Tissues used in Internal Dose Models

Organ Name

Adrenals Kidneys Skin*

Bone Surfaces Liver Spleen

Brain Extra-Thoracic Region Testes

Breast Lung Thymus

Stomach Wall Muscle Thyroid

Small Intestine Wall Ovaries Uterus

Upper Large Intestine Wall Pancreas Urinary Bladder Wall

Lower Large Intestine Wall Red Marrow

* Skin cancers are presumptive per SOP RA02.

Estimates of dose from an inhalation of the combined radionuclides in a mixture 

produced by alpha particles and by beta particles plus gamma rays are based on the 

following equation:

D(t )  AA(t )BRDCF(t )t

(1)

where

δD(t) = Increment in 50-year CED at time t to the organ or tissue (rem)

AA(t) =

Time-dependent airborne activity concentration of radioactive material 

(Ci m−3)

BR = Breathing rate (m3h

−1)

δt = Duration of exposure (h)

DCF(t) =

Time-dependent inhalation dose conversion factors for the composite 

radionuclides for the organ or tissue of interest (rem Ci−1)

Equation 1 gives the dose from inhalation of airborne radionuclides. Because most 

inhalation exposure scenarios associated with nuclear testing involve intakes of mixtures 

of radionuclides, the dose to an organ or tissue of concern is the sum of the doses from 

intakes of all of the radionuclides. Composite dose conversion factors (DCF) that apply to 

mixtures of radionuclides are used in most assessments. The radionuclide composition of 
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the mixture is based on shot-specific radiochemistry data. The concentration of 

radionuclides in fallout on the ground and in air and the associated DCFs are timedependent due to radioactive decay and in-growth. Operation-, shot-, and unit-specific 

assumptions, parameters, dose tables, and other relevant data for the calculation of 

internal doses are found in SOP Appendices A–C, and H.

There is little history of respiratory protection being used during nuclear tests at either the 

Nevada Test Site or the Pacific Proving Grounds. However, there is some indication that 

respiratory protection was used during cloud sampling operations (Martin and 

Rowland, 1982) and during Task Force RAZOR maneuver operations (Ponton et al., 

1981). 

5.2.1. Inhalation of Fallout Resuspended from Surfaces

Equation 2 is a generalized expression for the calculation of organ doses from the 

inhalation of resuspended fallout (DNA, 1986). 

 





end

start

t

t

Dinh GSMF I(t )FR(t )K t' BR DCFinh(t )dt

(2)

where

Dinh = 50-year CED to an organ from inhalation (rem)

GSMF = Gamma source modification factor1(See details in Section 5.2.1.1)

tstart = Time after detonation that veteran’s exposure started (h)

tend = Time after detonation that veteran’s exposure ended (h)

I(t) = Time-dependent gamma radiation intensity measured or estimated 

(R h

−1

)

FR(t) = Time-dependent, shot-specific ratio of surface activity density to 

radiation intensity (“FIIDOS Ratio”) for an infinite plane estimated 

using FIIDOS; historically designated SA/I (t) (Ci m−2per R h

−1

)

K(t') = Resuspension factor (m−1)

t' = Time after end of fallout deposition event (h)

BR = Breathing rate (m3h

−1

)

DCFinh(t) = Time-dependent, shot-specific inhalation DCF for an organ for the 

mixture of radionuclides in the fallout estimated using FIIDOS

(rem Ci−1)

 

1 The GSMF corrects the conversion ratios between the exposure rate and surface activity for contaminated surfaces 

that cannot be assumed infinite in spatial extent (see details in Section 5.2.1.1).
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The values of the input parameters for the deterministic models and parameter 

distributions used in the probabilistically-based analyses are given in Attachment 2.

When dose factors are not available for an affected organ or tissue, a surrogate organ or 

tissue is selected from the list provided in Attachment 1.

The FR(t) and DCFinh(t) are calculated using the FIIDOS computer code for shot-specific 

radionuclides inventories. The DCFs are discussed in further detail in Section 5.4.

The duration of exposure, tend − tstart, is based on the individual’s exposure scenario. 

Typically, the veteran’s external and internal doses are integrated over the period of 

exposure and are modified to account for shielding factors, e.g., when below deck on a 

ship or when indoors inside a tent or a building. It is also assumed that inhalation of 

resuspended contaminants only occurred when the participant was outdoors on land or 

topside on a ship. For inhalation of fallout resuspended from the deck of a ship or small 

boat, in addition to accounting for the fraction of time spent topside, tend is set to 

100 hours after the end of deposition; this is because any resuspendable fallout would 

have been washed out within 4 days of deposition (Goetz et al, 1991). 

In practice, the veteran’s inhalation dose from resuspended fallout is calculated using a 

modified version of Equation 2, with the DCFinh(t) replaced with values of DCF′inh(t) 

calculated using FIIDOS, that are specific to the shot(s) and organ(s) of interest, and that 

are normalized to 1 rem of dose to the whole body from a film badge reading or filmbadge equivalent calculation. For use in assessments of inhalation of resuspended fallout, 

DCFinh(t) and DCF′inh(t) are related by the following equation:

' ( ) ( )

0 0 0 DCF t

F

BR FR K

DCF t

inh

B

inh 

(3)

where

DCF′inh(t) = Time-dependent, shot-specific inhalation dose conversion factor (rem 

CED rem−1 i.e., CED in rem to organ of interest per rem of dose to the 

whole body from a film badge reading)

BR0 = Default breathing rate of 1.2 m3h

−1 used in FIIDOS to generate 

DCF′inh (t)

FR0 = Shot-independent constant value of the ratio of surface activity density 

to radiation intensity for an infinite plane (0.16 Ci m−2 per R h−1), 

derived in DNA (1986) and used in the development of FIIDOS DCFs

K0 = Default resuspension factor used in FIIDOS to generate DCF′inh (t), 

and equals 10−4 m−1
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FB = Film badge conversion factor2(rem R−1)

Combining Equation 2 and Equation 3 yields the following equation, which is typically 

used to calculate inhalation doses from resuspended fallout: 

 





end

start

t

t

inh

B

inh I t K t DCF t dt

K BR

GSMFBR F

D ( ) ' ' ( )

0 0

(4)

5.2.1.1 Gamma Source Modification Factor (GSMF)

To calculate internal doses at a location where no exposure rate data are available, use the 

value of GSMF that is applicable for the location where the measurement was taken with 

consideration of superstructure in the case of ships (Weitz, 2010a). It is incorrect to use 

the GSMF for the location where exposure occurred. Use of surrogate data from a nearby 

location is based on the assumption of similarity of the surface activity density at the 

location of the measurement and the location where a dose needs to be assessed. The 

exposure rates at the two locations should not be assumed to be similar. For example, the 

reconstructed internal dose for a destroyer that uses exposure rate measurements from a 

nearby aircraft carrier should be based on the GSMF for the aircraft carrier, not the 

destroyer. Similarly, the reconstructed internal dose for a ship that uses measurements of 

exposure rates at a nearby island should be based on the GSMF of an island rather than 

that of the ship. The mean values of GSMF for the deterministic models for various types 

of ships are given in (Weitz, 2010a, Table 2). 

5.2.1.2 Resuspension Factor

The resuspension factor, K(t'), adopted for use in deterministic land-based calculations is 

given by the time-dependent expression (Till and Meyer, 1983):

24 9

0 01 5

10 10









 

t

.

K(t ) e

(5)

The K(t') adopted for central estimates in probabilistically-based analyses for land-based 

calculations is given by the time-dependent expression (Anspaugh et al., 2002):

 

2 The film badge conversion factor (FB) is the ratio of dose recorded on a properly worn film badge to free-in-air 

integrated intensity. This factor, which accounts for body shielding of the film badge to gamma radiation, has been 

assigned the deterministic values of 0.7 for the standing position in a planar fallout field and 1.0 for one facing the 

source of radiation (e.g. a contaminated aircraft during engine maintenance).
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24 9

0.003

24 9

0.07 5

( ) 10 6 10 10















   

t t

K t e e

(6)

In addition, resuspension factors for specific short duration activities of test participants,

such as troop maneuvers involving helicopter operations in contaminated areas, aircraft 

decontamination, trucking, digging trenches, etc., are provided in Attachment 3. These 

resuspension factors should be used in lieu of Equations 5 and 6 for the periods of time 

relevant to those specific activities.

Table 2. Average GSMF for Various Ship Types

Ship Type Designation Example Length

(m)

Width

(m)

SuperStructure

Fraction

(SS)

Average 

GSMF

w/SS

Aircraft Carrier, ASW CVS USS BOXER 271 45 0

* 1.6

Aircraft Carrier, Escort CVE USS BAIROKO 203 32 0

* 1.7

Amphibious Force Flagship AGC USS ESTES 140 19 0.40 3.0

Attack Transport APA USS GENEVA 139 19 0.50 3.2

Battleship BB USS NEW YORK 175 29 0.50 2.6

Cruiser CA USS PENSACOLA 179 20 0.50 3.0

Destroyer DD USS MANSFIELD 115 12 0.50 4.0

Destroyer Escort DE USS SILVERSTEIN 93 11 0.50 4.3

Dock Landing Ship LSD USS BELLE GROVE 140 22 0.40 2.8

Fleet Oiler AO USS CACAPON 169 23 0.30 2.6

Fleet Tug ATF USS TAKELMA 62 12 0.35 3.8

Infantry Landing Craft LCI LCI-327 48 7 0.30 5.0

Salvage Ship ARS USS BOLSTER 65 12 0.50 4.2

Store Ship AF USS MERAPI 103 15 0.30 3.2

Submarine Rescue Ship ASR USS CHANTICLEER 77 13 0.60 4.4

Tank Landing Craft LCT LCT-1013 36 10 0

† 2.8

Tank Landing Ship LST USS LAWRENCE CO. 100 15 0.30 3.2

* As a first approximation, the superstructure of an aircraft carrier was neglected in this assessment because it is located on 

the extreme starboard side of the flight deck and therefore provides little shielding to those crewmembers who worked on 

the flight deck.

† LCT has a nearly rectangular deck with modest superstructure at far aft end.

5.2.1.3 Breathing Rate

The deterministic default breathing rate value is 1.2 m3h

−1

and applies to an adult male 

performing light activity comparable to walking at a rate of 3 miles per hour on a flat 

firm surface (ICRP, 1975). 
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For the probabilistic method, a triangular probability distribution function is used to 

characterize the variability of breathing rates for each activity level. The lower limit, 

mean, and upper limit of breathing rate distributions for each activity level are shown in

Table 3. They are used as the minimum, mode, and maximum values, respectively, for 

the triangular probability distribution function corresponding to each activity level. 

Samples for the triangular distributions are then multiplied by the average activity level 

fractions for each level of activity (Weitz et al., 2009). The fractions of time performing 

at each activity level can be adjusted based upon the veteran specific scenario and must

sum to 1. 

Table 3. Breathing Rate Distributions by Activity Level for NTPR Test Participants

Activity Level

Fraction of Time 

for each 

Level of Activity*

Breathing Rate Distributions (m3 h

−1)

Low Mean High

Rest 0.25 0.1 0.7 1.1

Light 0.60 0.2 1.4 2.7

Moderate 0.08 0.9 2.5 4.7

Heavy 0.07 1.4 3.3 7.6

* Example that should be changed as needed for other specific exposure scenarios.

5.2.1.4 Use of Film Badge Doses for Internal Dose Estimation

The internal dose commitment to an organ or tissue can be related to an external film 

badge dose or to a measured radiation intensity specific to a veteran’s location and 

exposure conditions. Use of film badge readings for internal dose reconstruction is 

subdivided into short-term exposures and long-term exposures. Short-term exposures are 

those for which the duration is short enough to justify use of an average value for the 

radiation intensity over the period of exposure. Long-term exposures are those for which 

variations in radiation intensity are such that an average value cannot be justified. For all 

uses of a film badge reading for calculation of internal dose due to inhalation of 

resuspended fallout, the film badge reading must be due primarily to the grounddeposited fallout. 

5.2.1.4.1 Short-Term Exposures

For short-term exposures, the reported dose for a film badge or badges worn by an 

individual can be used to estimate an average radiation intensity (Iaverage) via Equation 7, 

which can be substituted for I(t) and taken out of the integral in Equation 2 or 4 to 

estimate the inhalation dose, Dinh, accrued concurrently with the external gamma 

exposure recorded by the film badge(s). 
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(7)

where

DFB = Film badge dose (rem)

FB = Film badge conversion factor (rem R−1)

Δt = Time period of exposure corresponding to film badge (h)

5.2.1.4.2 Long-Term Exposures

For long-term exposures, Equation 2 or 4 can be used to estimate an inhalation dose, Dinh. 

However, the result should be multiplied by the ratio of the total film badge dose (see 

SM ED01) to the corresponding reconstructed whole body external dose estimated using 

a generic scenario of activities of the veteran’s unit, if available. However, to be 

conservative, the ratio should not be used if less than 1, i.e., when the total film badge 

dose is lower than the reconstructed external dose.

5.2.1.4.3 Period of Coverage of Film Badge Readings

For badge readings from continuous exposure over the period of coverage, e.g.,

permanent film badge or cohort film badge, the period of time integration used in 

Equation 2 or 4 to estimate an inhalation dose is defined by the issue and return dates of 

the badge. For mission film badges, the integration period is assumed to be 8 hours on the 

day of issue or as specified from scenario information. For mission film badges that 

exceed 1 day, an additional uncertainty due to the lack of knowledge of when the 

exposure occurred in this case is discussed in SM UA01.

5.2.2. Inhalation of Blast-Driven Resuspended Fallout from Previous Depositions

In response to the findings of a National Research Council review of the NTPR Program

(NRC, 2003), a special study was undertaken to characterize potential internal dose 

accrual to NTS participants from blast wave-driven resuspension of fallout deposited 

from previous detonations. A total of 16 exposure scenarios for which previously 

deposited fallout had the potential to contribute to internal doses of Exercise Desert Rock 

(EDR) participants were identified for the period 1952 to 1955. The 16 scenarios, the 

approach and methodologies employed, and the internal dose estimates are discussed in 

Dancz (2006). Internal dose estimates for the 16 specific scenarios during Operations 

TUMBLER-SNAPPER (1952), UPSHOT-KNOTHOLE (1953), and TEAPOT (1955) are 

included in SOP Appendices C-4 through C-6. For non-EDR scenarios, and scenarios 

after 1955, refer to the general methodology described below. The doses resulting from 

the use of the deterministic resuspension factors in Attachment 2 for the inhalation of 

blast wave-driven resuspended fallout are upper bounds.

F t

D

I

B

FB

average 


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Resuspension of previously deposited fallout by a nuclear detonation can occur in two 

regions near ground zero (GZ): the thermal-pulse (previously precursor) region and the 

blast-wave region (Kocher et al., 2009). The thermal-pulse region extends from GZ 

outward to the distance at which the peak overpressure at ground level associated with 

the blast wave is 6 pounds per square inch (psi) (Glasstone and Dolan, 1977). The 

blast-wave region extends from the outer limits of the thermal-pulse region to the 

distance at which the peak overpressure at ground level associated with the blast wave is 

2 psi. The method for determining the distances from GZ of the thermal-pulse region and 

the blast-wave region is based upon yield and height of burst of a detonation and is given 

in Kocher et al. (2009).

For deterministic analyses of blast-driven resuspension scenarios, the inhalation dose in 

each region is given by the following general equations:

Dinh,tp = BR ∫ I(t) FR(t) Ktp DCFinh

(t) dt

tendtp

tstarttp

(8)

Dinh,bw = BR ∫ I(t) FR(t) Kbw DCFinh

(t) dt

tendbw

tstartbw

(9)

where

Dinh,tp = 50-year CED to the organ from inhalation of blast-driven, resuspended 

fallout in the thermal-pulse region (rem)

tp start t = Start time of veteran’s exposure in the thermal-pulse region (h after shot 

H+0 that is the source of previously deposited fallout)

tp end t = End time of veteran’s exposure in the thermal-pulse region (h after shot 

H+0 that is the source of previously deposited fallout)

Ktp = Resuspension factor for the thermal-pulse region (m−1)

Dinh,bw = 50-year CED to the organ from inhalation of blast-driven, resuspended 

fallout in the blast-wave region (rem)

startbw

t = Start time of veteran’s exposure in the blast-wave region (h after shot 

H+0 that is the source of previously deposited fallout)

endbw

t = End time of veteran’s exposure in the blast-wave region (h after shot 

H+0 that is the source of previously deposited fallout)

Kbw = Resuspension factor for the blast-wave region (m−1)

Other variables as defined above, with I(t), FR(t), and DCFinh(t) specific to the shot that 

is the source of the previously deposited fallout. Similar to Equations 2–4 used for fallout 

resuspended by typical mechanical disturbances, the general equations shown above for 
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blast-driven resuspension can be modified to include DCF′inh(t). The resulting sum of the 

organ doses from each region are to be treated as both the best estimates and as the 

upper-bound doses (Kocher et al., 2009). The resuspension factors for blast-driven 

resuspension are listed in Attachment 2. These resuspension factors are to be applied for 

the 24 hours post detonation for resuspension in the thermal-pulse region and for 5 hours 

post detonation in the blast-wave region (Kocher et al., 2009).

For probabilistic analyses of blast-driven resuspension scenarios, resuspension factors for 

respirable and non-respirable fractions of resuspended fallout are available, as shown in 

Attachment 2 (Kocher et al., 2009). These resuspension factors are used as shown in the 

following equations:

Dinh,tp = BR

[

 

 

 

 

 KRtp ∫ I(t) FR(t)

tendtp

tstarttp

DCFinh

(t) dt

+ KNRtp ∫ I(t) FR(t)

tendtp

tstarttp

DCFing(t) dt ]

 

 

 

 

 

(10)

Dinh,bw = BR

[

 

 

 

 KRbw ∫ I(t) FR(t)

tendbw

tstartbw

DCFinh

(t) dt

+ KNRbw ∫ I(t) FR(t)

tendbw

tstartbw

DCFing(t) dt ]

 

 

 

 

(11)

where

Rtp

K = Resuspension factor for respirable particles (<10 m) in the thermalpulse region (m−1)

NRtp

K = Resuspension factor for non-respirable particles (10–100 m) in the 

thermal-pulse region (m−1)

Rbw

K = Resuspension factor for respirable particles (<10 m) in the blastwave region (m−1)

NRbw

K = Resuspension factor for non-respirable particles (10–100 m) in the 

blast-wave region (m−1)

DCFing(t) = Time-dependent shot-specific ingestion DCF for an organ for the 

mixture of radionuclides in the fallout estimated using 

FIIDOS (rem Ci−1)

Other variables are defined above as I(t), FR(t), DCFinh(t) and DCFing(t) specific to the 

shot that is the source of the previously deposited fallout. The resuspension factors for 

blast-driven resuspension of fallout are listed in Attachment 2. Similar to the 
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deterministic assessment of blast-driven resuspended fallout, the equations above can be 

modified to use DCF′inh(t), and the pathway should be assessed for the time periods 

indicated for the deterministic analysis. When using the above equations for inhalation of 

blast-driven resuspended fallout, it must be recognized that only a fraction of the nonrespirable taken in by inhalation are swallowed and cleared directly to the gastrointestinal (GI) tract. This fraction is currently under study, which is expected to produce 

an additional factor of about 0.3. Until this factor is included, doses will be 

overestimated.

5.2.3. Inhalation of Descending Fallout

The inhalation of descending fallout is a pathway for internal dose to a test participant 

who was outside (for land-based personnel) or topside (for shipboard personnel) during a 

fallout event. The fraction of time spent outside during descending fallout events is 

assumed to be 100 percent for land-based exposures regardless of the time during the day 

of fallout events. This is based on documented statements that additional precautions 

were not taken during fallout episodes on residence islands as described, for example, in 

the white book for CASTLE Naval Personnel (Thomas et al., 1984). For ship-based 

personnel, it is assumed that participants were inside/below deck during periods of 

descending fallout unless they had specific topside duties such as deck decontamination 

or operation of washdown systems (for example Thomas et al., 1984; Martin and 

Rowland, 1982). 

Conceptually, the fallout particles that descended at a participant’s location can be sorted 

into n particle size classes (denoted by index i = 1,..., n) according to their aerodynamic 

diameters. The most general equation for the internal dose accrued through this route of 

entry is then given by:







n

i

t

t

inh i inh i

end

start

D AA t BR t DCF t dt

1

,

( ) ( ) ( )

(12)

where the summation is over the particle size classes and

Dinh = 50-year CED to an organ from inhalation (rem)

tstart = Time from detonation to start of fallout (h)

tend = Time from detonation to end of fallout (h)

AAi (t) = Airborne activity density of particles in the i

th size class at time t

(Ci m−3)

BR(t) = Breathing rate at time t (m3h

−1

)

DCFinh,i (t) = Shot-specific dose conversion factor at t for CED to the organ of 

interest from inhalation of particles in the i

th size class (rem Ci−1

)
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The following assumptions are typically applied in deterministic assessments.

1. All fallout particles have aerodynamic diameters in the range of 1–10 μm.

2. The dose conversion factor DCFinh(t) is calculated with the computer code FIIDOS 

using the maximum of the values of the dose coefficients for particles with activity 

median aerodynamic diameters (AMADs) of 1, 3, 5, and 10 μm tabulated in 

ICRP (1996).

3. The duration of fallout deposition at the site of interest is much smaller than the time 

(after detonation) at which it occurred, that is, 

e s s

t  t  t .

4. The time of the peak intensity, tp, coincides with the end of fallout, te.

5. The deposition velocity is equal to the height of the stabilized cloud, H0 = 104 m, 

divided by tp.

6. The breathing rate BR(t) is constant with a default value (BR0) of 1.2 m3h

−1

.

7. The ratio of surface activity density to radiation intensity [(FR(t)], generated via the 

FIIDOS code and generally shot- and time-dependent, has a shot-independent, 

constant value of FR0 = 0.16 Ci m−2per R h

−1

, which was derived in DNA (1986) and 

used in the development of the DCF. 

Given these assumptions, Equation 12 reduces to the form used in deterministic 

assessments:

( ) ( )

0

inh B p p inh p

t I t DCF t

BR

BR D  GSMF F 

(13)

where, in addition to the parameters defined above, 

GSMF = Gamma source modification factor (See details in Section 5.2.1.1)

FB = Film badge conversion factor (0.7 or 1.0 rem R−1, see 

Section 5.2.1)

BR = Constant breathing rate appropriate for the exposure scenario

(m3h

−1

)

I(tp) = Peak gamma radiation intensity from the fallout (R h

−1

)

( ) inh p DCF t = Shot-specific inhalation dose conversion factor at tp with units 

rem CED rem−1i.e., CED (rem) to organ of interest per rem of 

dose to the whole body from a film badge reading

As used in assessments of descending fallout, DCF′inh(tp) and DCFinh(tp) are related by
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

 

 

( )[ ] ( )[ ]

1

0

1 0 0 DCF t rem Ci

F H

BR FR DCF t rem rem inh p

B

inh p

(14)

The values of the input parameters for the deterministic calculations are given in 

Attachment 2.

If Assumption 3 above is not valid, i.e., the duration of fallout deposition at the site of 

interest is not much smaller than the time (after detonation) at which it occurred, the 

simplified deterministic model represented by Equation (13) above for inhalation doses 

from descending fallout should not be used. Instead, use the following equation 

(Weitz, 2010b):

DCF t dt

t

I t FR t

dt

d

t t

H

GSMF BR D

e

s

t

t

inh

o

 

















   



 ( )

( )

( ) ( )

( )

1

(15)

where Λ(t) is a dimensionless function that represents the time dependence of FR(t) due 

to radioactive decay of fallout already deposited on the ground, and other variables are 

defined previously. The function Λ(t) can be derived empirically with the FIIDOS code 

(Raine et al., 2007) as the time scaling factors, or more generally approximated as 

(t/to)

−1.2

, to being a reference time usually 1. It is implicitly assumed in Equation 15 that 

there is no fractionation of fallout material with particle size, for otherwise Λ(t) must be 

indexed according to size bin. While some fractionation is likely, its inclusion is beyond 

the scope of the present analysis. Also, DCFinh1(t) is the shot-specific DCF at time t in the 

1-10 μm (i = 1) size class.

The decay factor for the integral of the derivative descending fallout model is assumed to 

be 1.2 (2.2 after six months) as indicated in Weitz (2010b) unless there are specific decay 

factors such as those for Shots BRAVO and ROMEO during Operation CASTLE. 

A more general formulation was developed for probabilistic applications (Weitz, 2010b). 

Assumption 1 above was removed through the use of three particle size classes and 

associated activity fractions and internal deposition fractions. Class 1 consists of particles 

with aerodynamic diameters between 1 and 10 μm, Class 2 between 10 and 20 μm, and

Class 3 between 20 and 100 μm; particles larger than 100 μm are considered noninhalable and therefore do not contribute to internal dose through the inhalation route of 

entry. The high-sided bias introduced by Assumption 2 was removed through the use of a 

bias factor as discussed in Section 5.4 (McKenzie-Carter and Stiver, 2009a), and 

Assumption 5 was mitigated through more rigorous modeling of the fallout deposition 

process (Weitz, 2009).
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To develop the probabilistic formulation, the fraction of total activity carried by all 

particles with aerodynamic diameters less than 100 μm is first calculated. Then the 

activity fractions AF1, AF2, and AF3 are calculated for the aerodynamic diameter ranges

1–10 μm (Class 1), 10–20 μm (Class 2), and 20–100 μm (Class 3), respectively. These 

particle size class activity fractions are calculated using the following equations:

AF1 = f1 AF100

AF2 = f2 AF100 (16)

AF3 = (1 − f1 − f2) AF100

where 

AF1 = Activity fraction for size Class 1 particles (1–10 μm)

f1 = Fraction of AF100 that is attributable to particles in size Class 1

AF100 = Fraction of total activity carried by all particles with diameters less 

than 100 μm

AF2 = Activity fraction for size Class 2 particles (10–20 μm)

f2 = Fraction of AF100 that is attributable to particles in size Class 2

AF3 = Activity fraction for size Class 3 particles (20–100 μm)

For a given fallout event, values of these parameters AF100, f1, and f2 are randomly 

sampled from their assigned triangular distributions. 

Settling velocities for particles of each size class are estimated as described in 

Weitz (2009). Log-triangular distributions are estimated for the velocity of descending 

fallout particles in each size class in the breathing zone, defined as the 1.6 m layer of air 

immediately above the Earth’s surface.

Respiratory tract deposition fractions are then defined for each particle size class as the 

fractions of inhaled particles in a given size class that deposit in a defined portion of the 

human respiratory tract. For use in the NTPR probabilistic methodology, deposition 

fractions for two regions are defined, the posterior extra-thoracic (ET2) region and 

thoracic (TH) airway (bronchial, bronchiolar, and alveolar-interstitial regions). Fractions 

that deposit in the ET2 region are treated as an ingestion intake. All activity associated 

with particles of size Class 1 (1–10 μm) has deposition fractions as defined in the 

underlying ICRP 66 human respiratory tract model. Lognormal distributions of 

deposition fractions for size Classes 2 (10–20 μm) and 3 (20–100 μm) are derived in 

McKenzie-Carter and Stiver (2009b). The values and distributions of these deposition 

fractions, designated by their Mathcad representations R1, R2 and R3 for the respective 

deposition of size Classes 1, 2 and 3 in the TH airway, and by NR1, NR2 and NR3 for the 

respective particle-size class deposition in ET2 region, are provided in Attachment 2. 
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The equation used for probabilistic assessments of internal dose from the inhalation of 

descending fallout is given by:





























































 





























( ) ( )

( )

( )

3

1 1

1

1

3

0 1

0

p ing p

i

i

i

i

i

i

inh p

i

i

i

B

inh p

FR t DCF t

R

R

NR NR

V

AF BR

BF

DCF t

R

R

V

AF

BR

BR F H

D GSMF I t

(17)

where

Ri = Fraction of i

th size class particles depositing in the thoracic airways of the 

respiratory tract (bronchial, bronchiolar, and alveolar-interstitial regions).

R1 = Fraction of particles in the 1–10 μm (i = 1) size class depositing in the 

thoracic airways of the respiratory tract

NRi = Fraction of i

th size class particles depositing in the posterior extra-thoracic 

(ET2) region of the respiratory tract and cleared to the GI tract

NR1 = Fraction of particles in the 1–10 μm (i = 1) size class depositing in the ET2

region of the respiratory tract and cleared to the gastro-intestinal tract

Vi = Deposition velocity (m h

−1

), or average velocity of descent in the 

breathing zone (nominally up to 1.6 meters above the surface) for i

th

-sized 

particles

H0 = The height of the stabilized cloud (104 m)

BF = Bias factor, to remove the bias introduced by Assumption 2 above (also 

see Section 5.4, Table 6).

FR(tp) = FIIDOS-generated time-and shot-dependent ratio of surface activity 

density to intensity at time tp, referred to as the “FIIDOS ratio”

(Ci m−2per R h

−1

)

The input parameter value distributions used in the probabilistic methods of analysis are 

given in Attachment 2.

5.2.4. Inhalation of Suspended Soil Activation Products

The method for estimating airborne concentrations of radionuclides due to suspension of 

radioactive material produced by neutron activation in soil at the NTS is similar to the 

method used in Section 5.2.1 involving resuspension of deposited fallout. However, 

FIIDOS DCFs are not used. See SOP Appendix A-1 for methodologies to be used for 

locations in Japan. 
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Relative activities of activation products in soil are estimated on the basis of the 

following inputs:

 Field radiation measurements from known activation products 

 Known elemental compositions of soil 

 Neutron transport in air and soil 

 Neutron capture in nuclei of stable elements in soil

 Known decay characteristics of the activation product radioisotopes. 

Activities of radionuclides per unit volume of soil (Ci m−3) are then estimated by scaling 

the estimated relative activities to a calculated photon exposure in air above ground or 

exposure rate at a particular time that matches available measurements with film badges 

or field instruments, taking radioactive decay into account. The intensity INa(t) due to 

Na-24 is estimated as a percentage of the total exposure rate by using the table of 

fractions listed in Table 4 for the appropriate location. The intensity from Na-24 at time 

equals zero INa(0) is then calculated using the half-life of Na-24. The activities per square 

meter of the radionuclides of interest are then calculated using the appropriate conversion 

factor in Table 5 (Goetz, et al., 1981). Radionuclide activities per unit volume of surface 

soil are converted to equivalent surface activity concentrations (Ci m−2) by assuming the 

top 1 cm of soil can be suspended in the air and contains the total activity in the soil 

profile. Finally, a resuspension factor is applied to the estimated surface activity 

concentrations of radionuclides in surface soil to obtain an estimate of the concentrations 

in air. 

Resuspension factors applied to activation products in surface soil are the same as those 

applied to deposited fallout (see Section 5.2.1). As with resuspension of deposited fallout, 

an important condition in using this method is that the film badge or instrument readings 

must be due primarily to activation products in soil (DNA, 1986; NRC, 2003).
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Table 4. Ratio of Intensity Due to Na-24 to Intensity

Due to all Neutron Activation Products [IR,Na(tm)]

Time after 

Shot (h)

Area 7 

NTS

Frenchman Flat 

NTS

0 0.002 0.001

1 0.323 0.196

2 0.374 0.233

3 0.426 0.273

4 0.481 0.317

5 0.535 0.364

6 0.589 0.414

7 0.640 0.464

8 0.688 0.514

9 0.732 0.562

10 0.772 0.608

11 0.806 0.651

12 0.837 0.690

13 0.862 0.725

14 0.884 0.755

15 0.903 0.782

16 0.918 0.805

17 0.931 0.824

18 0.941 0.840

19 0.950 0.854

20 0.957 0.865

21 0.962 0.874

22 0.967 0.882

23 0.971 0.889

24 0.974 0.894

Table 5. Relative Surface Radioactivity of Neutron Activation Products to

Na-24 Intensity, [SAi(0)]

Radioisotope SAi(0)

* Half Life of Radioisotope

Na-24 1.7 × 10−3 15.0 hours

P-32 4.0 × 10−7 14.3 days

K-40 3.5 × 10−4 12.4 hours

Ca-45 5.5 × 10−7 163 days

Mn-56 3.7 × 10−3 2.58 hours

*

 The surface density of radioactivity (Ci m−2) per R h

−1 of radiation intensity from Na-24 at time t = 0.
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Based on the previous discussion, the inhalation dose from activation products in 

suspended soil is estimated using the following equations: 

Dinh = INa(0)BR∑SAi

(0)

i

DFi ∫ K(t)

tend

tstart

e

−

0.693 t

HLi dt (18)

INa(0) = I(tm) IRNa(tm) e

0.693 tm

HLNa (19)

where

Dinh = 50-year CED to an organ from activation products in suspended soil 

(rem)

INa(0) = Intensity due to Na-24 at time equal zero (R h

−1

)

tm = Time of intensity measurement after detonation (h)

I(tm) = Measured intensity at time tm (R h

−1

)

IR,Na(tm) = Ratio of intensity due to Na-24 to total measured intensity at time tm

SAi(0) = Ratio of surface activity for the i

th isotope to intensity due to Na-24 at 

time equals zero (Ci m−2per R h

−1

)

DFi = Inhalation dose coefficient for the organ of interest from ICRP-72 

(ICRP, 1996) for the i

th isotope (rem Ci−1

).

HLi = Half-life of the i

th neutron activation product (h)

HLNa = Half-life of Na-24 (h)

The time-dependent ratios of intensity due to Na-24 to total measured intensity IRNa(tm) at 

time tm are included in Table 4. Table 5 lists the intensity to surface activity conversion 

factors (SAi(0)) for neutron-activated products at NTS at time equals zero for neutroninduced radioactivity that can lead to significant internal doses. Values of other input 

parameters for the deterministic models and parameter distributions used in the 

probabilistically-based analyses are given in Attachment 2.

5.2.5. Inhalation in an Atmospheric Cloud

The scenario involving inhalation of radionuclides in an atmospheric cloud is applied 

only for individuals who flew through nuclear cloud debris in an airplane or helicopter. 

For this scenario, the inhalation dose is calculated as follows:

D =

1

RPF ∫ I(t) (

AA

I

(t)) BR DCFinh

tend

tstart

(t) dt (20)
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where

t

I

AA = Time-dependent, shot-specific airborne activity concentration–to–

intensity ratio estimated using FIIDOS (Ci m−3per R h

−1

)

RPF = Respiratory Protection Factor from any respiratory protection used 

during the flight (USNRC, 1999) (dimensionless)

Values of 

t

I

AA

are shot-specific and are included in SOP Appendix H. They are 

calculated using FIIDOS based on an assumption that the atmospheric cloud is uniformly 

contaminated and infinite in extent since the aircraft were submerged in the radioactive 

cloud. The quantities, I(t), t

I

AA

, and DCFinh(t) are time-dependent, and 

t

I

AA

and 

DCFinh(t) are based on an assumed mixture of radionuclides in air (DNA, 1986; 

NRC, 2003).

For the inadvertent exposure of a person in an aircraft to a radioactive cloud, it is 

assumed that no respiratory protection was used. However, in cases of expected 

exposure, such as during cloud sampling, it is assumed that respiratory protection was 

used and that the equipment provided complete protection against inhalation of airborne 

contamination unless otherwise indicated in historical documents and reports. Thus, the 

inhalation dose in cases of expected exposures is typically zero (NRC, 2003).

5.3 Ingestion Intakes

Two principal models are employed for the evaluation of internal dose to nuclear test 

participants from the ingestion of radioactive contamination:

 Direct deposition of contaminants on consumed food and beverages during fallout 

events, and 

 Incidental ingestion of contaminated soil and dust during routine daily activities. 

The direct deposition model requires the characterization of the radiation environment 

and the participant’s activities therein, and is described in Section 5.3.1. Because data for 

such characterization are not generally available, the direct deposition model requires that 

the analyst assume scenario elements and parameter values, most of which are based on 

experience and consensus judgment among radiation assessment analysts rather than 

published, peer-reviewed data. The incidental daily ingestion model (Section 5.3.2) 

requires fewer assumed parameter estimates, no assumptions regarding the mode of 

intake, and ingestion rates that are based on published technical guidance from the U.S. 

Environmental Protection Agency (USEPA) and the U.S. Army Center for Health 

Promotion and Preventive Medicine (USACHPPM). Because the incidental daily 
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ingestion model uses the highest estimated intake rate for an adult carrying out strenuous 

activities for the entire period of presence in a soil/dust-contaminated environment, 

resultant doses are credible estimates of upper bound doses for the deterministic method. 

5.3.1. Ingestion of Fallout Deposited on Food

The ingestion of descending fallout deposited on consumed food will be included as an 

internal dose pathway only if after a careful review of the Scenario of Participation and 

Radiation Exposure (SPARE) and other relevant information in the case file or historical 

documents, the analyst concludes that the participant could have been exposed to 

descending fallout while eating a meal outdoors or topside on a ship. This determination 

should be based on statements made by the participant and contemporaneous records and 

reports. 

The model is based on the amount of fallout that would have fallen on the participant’s 

food during the meal at the average rate of deposition as determined from intensity 

buildup data and the geometric properties (size and shape) of the food consumed. The 

model for estimating internal dose from the ingestion of food contaminated by 

descending fallout requires the following types of information: 

 A set of well-characterized measurements of intensity buildup during the period of 

deposition, typically at least three or more time-intensity data pairs

 A description of the veteran’s activities and conditions of exposure during fallout 

deposition, including:

- Periods of fallout occurring when meals would have been consumed

- Participant involvement in activities that would have precluded the consumption 

of food during the period of deposition; e.g., topside decontamination crew

- If the participant was in a ship during fallout deposition, whether the ventilation 

system was opened or closed.

 A description of the type of food consumed, its geometric properties (size, shape),

and those of the plate or tray, if used

- Lacking such information, a 15-minute deposition on a 9-inch diameter plate at 

the average rate of deposition is assumed. A period of 15 minutes (0.25 hours) is 

based on the approximate time needed to consume a meal.

If data are not sufficient to characterize the potential intake as described above, in landbased scenarios the incidental ingestion of soil and dust model described in Section 5.3.2

should be used.

Since sealed food stores prevent primary contamination of foodstuff, such contamination

is not considered a viable route of entry of fallout material into the body. Additionally, 

routine mess hall cleaning precludes repeated exposures at the initial level. 
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Contamination deposited on surfaces such as the ground is ingested only if it enters the 

food chain. Since routine meals were prepared from imported foodstuff and drinking 

water, ground contamination is not considered to be a significant source of internal dose 

from ingestion (NRC, 2003).

5.3.2. Incidental Ingestion of Contaminated Soil and Dust

Based on past studies and guidelines of the USEPA and USACHPPM, routine daily 

activities by nuclear test participants may have involved the inadvertent ingestion of 

small quantities of soil and dust particles that adhered to food, beverages, cigarettes, or

hands (USEPA, 1996, 1997 and 2002; USACHPPM, 2003). Therefore, nuclear test 

participants at land locations had the potential for the incidental ingestion of 

contaminated soil and dust in the course of their regular daily activities. NTS participants 

were principally involved in routine activities at their temporary-duty stations in the 

vicinity of the NTS, mainly Camp Desert Rock (CDR), Camp Mercury and Indian 

Springs Air Force Base (ISAFB). PPG participants were primarily land-based garrison 

force personnel and others stationed at residence islands for extended periods as well as 

ship-board personnel. The incidental ingestion of soil and dust is not a potential pathway 

for ship-based personnel, except for extended periods of time spent on ashore; this does 

not apply for time spent on liberty ashore for recreation. 

The incidental ingestion pathway is a chronic type of exposure that involves the daily 

intake of relatively small quantities of contaminated soil and dust. The source of the 

ingested contamination includes direct contact and airborne soil and dust due to walking, 

vehicular traffic, and wind-driven lofting of contaminated particles in areas where 

military personnel were stationed during nuclear testing operations.

The ingestion dose for the incidental intake of soil and dust is calculated as 

follows (Chehata and Stiver, 2009):





end

start

t

t

ing

soil soil

ing

ing I t FR t DCF t dt

b

q

D GSMF ( ) ( ) ( )



(21)

where

Ding = 50-y CED to an organ due to ingestion of radioactive materials (rem)

ρsoil = Bulk density of soil (g m−3)

qing = Average incidental ingestion rate (g h

−1

)

DCFing(t) = Time-dependent activity-weighted average (composite) ingestion 

DCF (rem Ci−1)

bsoil = Thickness of soil layer available for intake, generally assumed to be 

1 centimeter (0.01 meter)
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The values of the input parameters for the deterministic models and parameter 

distributions used in the probabilistically-based analyses are given in Attachment 2.

This pathway is applicable only to land-based personnel. The GSMF is equal to 1 if I(t) 

are land-based intensity measurements, and is equal to a value applicable to a nearby ship 

if the I(t) measurement was made on that ship.

Further information concerning the calculation and application of the average GSMF is 

found in Section 5.2.1.1. Average GSMFs for various ship types are provided in Table 2.

Given the considerations detailed in Chehata and Stiver (2009), it was recommended that 

the NTPR adopt an incidental ingestion model using a soil/dust ingestion rate of 

500 mg day−1as an upper-bound value for the entire period of residence. This 

upper-bound rate should be used for personnel who were stationed at NTS facilities while 

carrying out routine daily activities at CDR, Camp Mercury, ISAFB, and other similar 

locations, where dusty conditions were prevalent. The incidental ingestion model is also 

applicable to personnel located on shore at the PPG. The upper-bound rate is consistent 

with the highest value recommended in USEPA screening level guidance and 

USACHPPM exposure guidance for deployed military personnel (USEPA, 1996, 1997 

and 2002; USACHPPM, 2003). 

For the probabilistically-based approach, several types of distributions have been utilized 

in past studies or cited as examples in USEPA guidance (e.g., USEPA, 2001). However, 

due to the limited information on this parameter, a skewed triangular distribution is 

recommended unless better data are available. Ranges of the parameters of the triangular 

distribution are given in Attachment 2 and are based on the data compilation cited above. 

The estimation of internal doses using measurements of activity on the ground requires 

knowledge of the bulk density of soil. At NTS, surface soils are characterized as being 

moderately- to poorly-sorted sand to silty loam. These soils have a bulk density that 

ranges from 1.3 to 1.6 g cm−3 with an average of 1.45 g cm−3(Hillel, 1980). A 

symmetrical triangular or a uniform probability distribution can be used unless sitespecific data supports another type of distribution (Chehata and Stiver, 2009). Soil 

density at the PPG residence islands would be slightly higher but within a similar range. 

For the deterministic model, the lower value of 1.3 g cm−3leads to the more conservative

result in the dose (See Equation 21). Distributions and deterministic (high-sided) 

parameter values are given in Attachment 2.

As with resuspension of deposited fallout, an important condition in using the incidental

ingestion model is that the film badge or instrument readings must be due primarily to 

ground-deposited fallout. 

The method described here does not apply to the assessment of doses in acute exposure 

situations such as event-driven ingestion of descending fallout deposited on food (see 

Section 5.3.1), when parameters, such as time and deposited quantities, are well-known 

or can be estimated with a relatively higher degree of confidence. 
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5.4 Use of FIIDOS in Dose Reconstructions

FIIDOS is a computer code developed for internal dose calculations that is used to 

generate DCFs for the calculation of internal dose from intakes of radioactive materials. 

For most radiation dose assessments involving inhalation, FIIDOS has been used to 

generate shot-specific, time-dependent DCF tables (Raine et al., 2007; ICRP, 1994 and 

1995). The analyst should be aware of three aspects of the methodology that impose 

limitations on the application of FIIDOS. All three relate to the use of a radiological 

measurement to characterize a radiological environment. (Raine et al., 2007)

 First, the radiological measurement represents the radioactive contamination at a 

specific location only. The radiological environment that FIIDOS calculates is 

referenced to that same location. FIIDOS does not provide a mechanism for 

translating a radiological measurement at one location to another location. 

 Second, when a radiological measurement made at one time is used to determine the 

radiological environment at a different time, the only effect that FIIDOS considers is 

radioactive decay. Decontamination and other effects that alter the distribution of the 

radioactive material, such as wind and rain, are not included in the FIIDOS

methodology. 

 Third, the association of the radiological hazard with the radiological measurement is 

valid only as long as the fallout debris emits sufficient gamma-ray radiation to give 

meaningful measurements. This condition exists in a fresh fallout field and can 

continue for several years; however, after some time, the fallout radiation level will 

become indistinguishable from the prevailing background radiation level. At these 

late times, the fallout material could still contain some radionuclides, such as certain 

actinides that contribute significantly to an internal dose, even though the gamma-ray

radiation emission rate from the fallout material is low.

Separate sets of tables are generated for DCFinh(t) and DCF′inh(t) as follows:

 Tabulated values for DCFinh(t) are calculated to produce the CED to an organ, in rem,

from the intake of 1 curie of a mixture of fallout radioactivity calculated by FIIDOS

(rem CED Ci-1).

 Tabulated values for DCF′inh(t) are calculated to produce the CED to an organ, in

rem, per rem of dose to the whole body from a film badge reading (rem CED rem-1).

DCF′inh(t) uses reference values for the resuspension factor and the breathing rate as 

follows:

- The reference resuspension factor used is K0 =10−4 m−1

- The reference breathing rate used is BR0 = 1.2 m3h

−1

 In deterministic (high-sided) models, maximum inhalation DCFs are selected from 

those calculated for particle size distributions of 1, 3, 5, and 10 m AMAD using the 
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ICRP 72 dose coefficients for the recommended absorption type of the oxide form of 

each radioactive material.

For both inhalation and ingestion, separate DCF tables have been generated for the 

calculation of doses from alpha particles, and from beta particles and gamma rays 

combined for each organ at various times following a detonation. For inhalation intakes, 

separate tables are provided for both radiation types for the doses normalized to 1 rem 

film badge equivalent dose (DCF′inh(t)) and also to 1 curie of total radioactivity inhaled

(DCFinh(t)). For ingestion intakes, tables are provided for both radiation types only for 

doses normalized to 1 curie of total radioactivity ingested (DCFing(t)). SOP Appendix H

contains the tables for each shot for each test series for which radiochemistry data are 

available.

To use the deterministic inhalation DCFs in a probabilistically-based analysis, bias 

factors, BF (Table 6), are used to estimate adjusted central values of the inhalation DCFs

(McKenzie-Carter and Stiver, 2009a). Incorporating the bias factor into a 

probabilistically-based analysis is accomplished as follows: 

BF

DCF DCFadj 

(22)

where

DCFadj = Adjusted (unbiased) shot-specific, time-dependent inhalation DCF

(rem CED per rem film badge dose, or rem CED Ci−1)

BF = Organ-specific bias adjustment factor for inhalation DCFs (Also see 

BF definition following Equation (17))

Table 6. Organ-Specific Inhalation DCF Bias Adjustment Factors, BF

Organ(s) Alpha Radiation

Beta-plusGamma 

Radiation

Lung, breast, thymus, adrenals, 

spleen, liver, and pancreas 1.3 1.35

Extra-thoracic region 1.15 1.2

All FIIDOS organs not listed 

elsewhere in table 1.3 1.2
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Data and Input

Operation- and shot-specific data are compiled in SOP Appendices A–C). The values of 

the input parameters for both the deterministic and probabilistic models are given in 

Attachment 2. Values for the time-dependent surface activity–intensity ratio, FR(t),

t

I

AA

, DCFinh(t), DCF′inh(t) and DCFing(t) are provided in SOP Appendix H.

Referenced SOPs and Standard Methods from this Manual

(1) SOP RA01 - Radiation Dose Assessment for Cases Requiring Detailed Analysis

(2) SOP RA02 - Expedited Processing of Radiation Dose Assessments for Atmospheric 

Nuclear Weapons Testing Veterans

(3) SM ED01 - Film Badge Dose Assessment

(4) SM UA01 - Dose Uncertainty and Upper-Bound Dose Determinations

References

Anspaugh, L.R., Simon, S.L., Gordeev, K.I., Likhtarev, I.A., Maxwell, R.M., and Shinkarev, 

S.M., 2002. “Movement of Radionuclides in Terrestrial Ecosystems by Physical 

Processes,” Health Physics, 82:669–679.

Chehata, M. and Stiver, J.H., 2009. Evaluation of Internal Doses from Incidental Ingestion of 

Contaminated Soil and Dust for NTPR Participants. NTPR-TM-09-03, Defense Threat 

Reduction Agency, Fort Belvoir, VA.

Dancz, J., 2006. Upper-Bound Internal Dose Calculations for Highly-Resuspended EDR 

Exposures to NTS Fallout through 1955. Draft Report, Science Applications International 

Corporation, McLean, VA. December 28.

DNA (Defense Nuclear Agency), 1986. Low Level Internal Dose Screen – CONUS Tests. DNATR-85-317, Defense Nuclear Agency, Washington, DC. 

DoD (Department of Defense), 2020. “Guidance for the Determination and Reporting of Nuclear 

Radiation Dose for DoD Participants in the Atmospheric Nuclear Test Program (1945-

1962).” Title 32, Code of Federal Regulations, Part 218. Washington, DC. July 1.

Glasstone, S. and Dolan, P.J., 1977. The Effects of Nuclear Weapons. Third Edition. U.S. 

Department of Defense and U.S. Department of Energy, Washington, DC.

Goetz, J., Klemm, J., McRaney, W., Barrett, M., 1991. Low Level Internal Dose Screen-Oceanic 

Tests. DNA-TR-88-260, Defense Nuclear Agency, Alexandria, VA. October 1. 

Goetz, J., McGahan, J., Kaul, D., Weitz, R., Klemm, J., 1981. Analysis of Radiation Exposure 

for Troop Observers Exercise Desert Rock V, Operation Upshot-KNOTHOLE. 

DNA 5742F, Defense Nuclear Agency, Washington, DC. 

Hillel, D., 1980. Fundamentals of Soil Physics. 413 p. Academic Press, New York, NY.
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ID01 –Doses to Organs from Intake of Radioactive Materials

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Page 31 of 43

ICRP (International Commission on Radiological Protection), 1990. 1990 Recommendations of 

the International Commission on Radiological Protection. ICRP Publication 60, Ann. 

ICRP 21(1-3), Pergamon Press, Elmsford, NY.

ICRP (International Commission on Radiological Protection), 1994. Human Respiratory Tract 

Model for Radiological Protection. ICRP Publication 66, Ann. ICRP 24(1-3), Pergamon 

Press, Elmsford, NY.

ICRP (International Commission on Radiological Protection), 1995. Dose Coefficients for 

Intakes of Radionuclides by Workers. ICRP Publication 68, Ann. ICRP 24/4, Pergamon 

Press, Elmsford, NY.

ICRP (International Commission on Radiological Protection), 1975. Report of the Task Group on 

Reference Man. ICRP Publication 23, International Commission on Radiological 

Protection, Pergamon Press, Elmsford, NY. Accessed on April 29, 2021 at: 

https://www.icrp.org/publication.asp?id=ICRP%20Publication%2023. 

ICRP (International Commission on Radiological Protection), 1996. Age-Dependent Doses to the 

Members of the Public from Intake of Radionuclides Part 5, Compilation of Ingestion and 

Inhalation Coefficients. ICRP Publication 72, Ann. ICRP 26/1, Pergamon Press, 

Elmsford, NY.

Kocher, D.C., Trabalka, J.R., Apostoaei, A.I., 2009. Derivation of Effective Resuspension 

Factors in Scenarios for Inhalation Exposure Involving Resuspension of PreviouslyDeposited Fallout by Nuclear Detonations at Nevada Test Site. DTRA-TR-09-15, 

Defense Threat Reduction Agency, Fort Belvoir, Virginia.

Martin, E., and Rowland, R., 1982. Castle Series, 1954. DNA 6035F, Defense Nuclear Agency, 

Washington, DC. 

McKenzie-Carter, M., and Stiver, J.H., 2009a. Bias Adjustments for use with FIIDOS Inhalation 

Dose Conversion Factors. NTPR-TM-09-08, Defense Threat Reduction Agency, Fort 

Belvoir, VA.

McKenzie-Carter, M. and Stiver, J., 2009b. Deposition Fraction Modifications for 

Inhalation of Descending Fallout. NTPR-TM-09-08, Defense Threat Reduction Agency, 

Fort Belvoir, VA.

NRC (National Research Council), 2003. A Review of the Dose Reconstruction Program of the 

Defense Threat Reduction Agency. The National Academies Press, Washington, DC. 

Ponton, J., Wilkinson, M., and Rorher, S., 1981. Shot Apple 2, A Test of the Teapot Series 5 May 

1955. DNA 6012F, Defense Nuclear Agency, Washington, DC.

Raine, D.A. III, Egbert, S.D., Stiver, J.H., and Case, D.R., 2007. FIIDOS - A Computer Code for 

the Computation of Fallout Inhalation and Ingestion Dose to Organs, Computer User’s 

Guide (Revision 4). DTRA-TR-07-11, Defense Threat Reduction Agency, Fort Belvoir, 

VA.
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Thomas, C., Goetz, J., Klemm, J., and Weitz, R., 1984. Analysis of Radiation Exposure for Naval 

Personnel at Operation CASTLE. DNA-TR-84-6, Defense Nuclear Agency, Washington, 

DC. February 28.

Till, J.E., and Meyer, H.R., 1983. Radiological Assessment – A Textbook on Environmental Dose 

Analysis. NUREG/CR-3332, USNRC, Washington, DC.

USACHPPM (U.S. Army Center for Health Promotion and Preventive Medicine), 2003. 

Reference Document (RD) 230, Exposure Guidelines for Deployed Military, a

Companion Document to Technical Guide (TG) 230, Chemical Exposure Guidelines for 

Deployed Military Personnel, Version 1.3. Edgewood Proving Ground, MD. May.

USEPA (U.S. Environmental Protection Agency), 1996. Soil Screening Guidance: Technical 

Background Document. EPA/540/R-95/128.

USEPA (U.S. Environmental Protection Agency), 1997. Exposure Factors Handbook. Office of 

Research and Development, Washington, D.C., EPA/600/P-95/002Fa-c.

USEPA (U.S. Environmental Protection Agency), 2001. Risk Assessment Guidance for 

Superfund (RAGS) Volume III - Part A: Process for Conducting Probabilistic Risk 

Assessment. EPA 540-R-02-002, OSWER 9285.7-45, PB2002 963302.

USEPA (U.S. Environmental Protection Agency), 2002. Supplemental Guidance for Developing 

Soil Screening Levels for Superfund Sites. OSWER 9355.4-24.

USNRC (U.S. Nuclear Regulatory Commission), 1975. Reactor Safety Study – An Assessment of 

Accident Risks in Commercial Nuclear Power Plants. NUREG-75/014, Appendix VI.

USNRC (U.S. Nuclear Regulatory Commission), 2020. “Assigned Protection Factors for 

Respirators,” Title 10, Part 20, Appendix A, Code of Federal Regulations. January 1.

Weitz, R., 2009. Characterization of Descending Fallout. NTPR-TM-09-06, Defense Threat 

Reduction Agency, Fort Belvoir, VA.

Weitz, R., 2010a. Formulation of the Gamma Source Modification Factor for Ship-based 

Applications, Revision 1. NTPR-TM-09-04(R1), Defense Threat Reduction Agency, Fort 

Belvoir, VA. November 30.

Weitz, R.L, 2010b. Internal Dose from Inhalation of Descending Fallout, Revision 1. NTPRTM-09-07 (R1), Defense Threat Reduction Agency, Fort Belvoir, VA. November 30.

Weitz, R. Case, D., Chehata, M., Egbert, S., Mason, C., Singer, H., Martinez, D., McKenzieCarter, M., Shaw, R., and Stiver, J., 2009. Probabilistic Approach to Uncertainty 

Analysis in NTPR Radiation Dose Assessments. DTRA-TR-09-13, Defense Threat 

Reduction Agency, Fort Belvoir, VA. 
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Attachment 1.

Cross Reference of Organs, Tissues, and Diseases

for Internal Dose Assessment

This attachment consists of Table A1-1 that lists potentially diseased organs and tissues,

cross referenced to NTPR Standard Organs3for use in NTPR internal dose calculations. 

Some of the organs and tissues listed in the first column of the table correspond directly 

to NTPR standard organs (e.g., adrenal glands), for which FIIDOS DCFs are available. 

For other organs and tissues or diseases (e.g., arthritic tissue), FIIDOS DCFs are not 

available and surrogate organs have been determined. The surrogate organs or tissues 

were determined based on similarity to the anatomy, physiology, and biokinetics of the 

organs, tissues, and diseases for which there are no NTPR standard organs. Entries in the 

“NTPR Standard Organ Type” column of the table indicate whether the assignment in the 

NTPR Standard Organ column is an actual NTPR Standard Organ used in FIIDOS 

calculations (“FIIDOS”), or if it is an NTPR Standard Organ selected as a surrogate for 

the diseased organ (“Surrogate”). When conducting a dose assessment for an organ, 

tissue or disease listed in the first column, the DCFs for the identified NTPR standard 

organ should be used. More detailed rationale describing the technical association 

between the individual organs or diseases and the surrogate organs will be documented 

elsewhere in the future. 

 

3 A complete list of NTPR Standard Organs is listed in Table 1 of this SM.
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Table A1-1. Cross Reference of Diseased Organs, Tissues and Diseases

and Corresponding NTPR Standard Organs*

Organ, Tissue, or Disease NTPR Standard 

Organ

NTPR Standard 

Organ Type†

Acute lymphocytic leukemia (ALL) Red Marrow Surrogate

Acute myeloid leukemia (AML) Red Marrow Surrogate

Adrenal glands Adrenals FIIDOS

Arthritic Tissue Bone Surface Surrogate

Bladder Urinary Bladder Wall FIIDOS

Blood, bone marrow, red marrow, yellow 

marrow, leukemia (excluding ALL, AML, 

CLL, and CML)‡

Red Marrow FIIDOS, Surrogate

Bone, bone surface, endosteum, joints, and 

all other bones (e.g., ankle, elbow, femur, 

hand, jaw, pelvis, shoulder, spine, 

vertebrae)

Bone Surface FIIDOS, Surrogate

Brain, anterior commissure, brain stem, 

cranial nerve

Brain FIIDOS, Surrogate

Breast Breast FIIDOS

Cervix Uterus Surrogate

Chronic lymphocytic leukemia (CLL) Spleen Surrogate

Chronic myeloid leukemia (CML) Red Marrow Surrogate

Connective tissue Muscle Surrogate

Endocrine glands (endocrine glands not 

included elsewhere)

Specific diseased organ 

must be known.

Surrogate

Esophagus ET Region‡ FIIDOS

Eye, choroid, retina Brain Surrogate

Gallbladder, bile duct Liver Surrogate

Heart, aorta, atrial sarcoma Muscle Surrogate

Kidney Kidney FIIDOS

Larynx, including glottis, vocal cords ET Region‡ Surrogate

Lipoma Muscle Surrogate

Liver Liver FIIDOS

Lower large intestine, colon, large 

intestine 

LLI Wall‡ FIIDOS, Surrogate

Lung, trachea Lung FIIDOS, Surrogate
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Table A1-1. Cross Reference of Diseased Organs, Tissues and Diseases

and Corresponding NTPR Standard Organs*(cont.)

Organ, Tissue, or Disease NTPR Standard Organ NTPR Standard 

Organ Type†

Lymph system, including lymph glands, 

lymph nodes, lymphatic tissue, lymphoma

Thymus (If this is 

primary disease)

Surrogate

Middle ear Brain Surrogate

Muscle, including, thigh muscle, eye 

muscle, eyelid muscle, neuro-muscular

Muscle FIIDOS, Surrogate

Nasal cavities, including sinus (maxillary), 

sinus (nasal), nasal tip

ET Region‡ Surrogate

Nervous system, spinal cord, spine nerves Brain Surrogate

Neuroendocrine system, including 

hypothalamus, pituitary gland, pineal gland

Brain Surrogate

Oral cavity and pharynx, including 

epiglottis, gum, hypopharynx, lip, mouth, 

nasopharynx, oropharynx, palate, parotid 

gland, pharynx, salivary gland, throat, 

tongue, tonsil, uvula, and nasolabial fold 

(specific disease needed if not skin cancer) 

ET Region‡ Surrogate

Ovary Ovary FIIDOS

Pancreas Pancreas FIIDOS

Parathyroid Thyroid Surrogate

Peritoneum, peritoneal cavity muscle Muscle Surrogate

Pleura Lung Surrogate

Rectum, anus, anal canal LLI Wall‡ Surrogate

Respiratory other than Lung ET Region‡ Surrogate

Small intestine, duodenum SI Wall‡ FIIDOS, Surrogate

Soft tissue, e.g., hip, shoulder, thigh, upper 

arm

Muscle Surrogate

Spleen Spleen (Use only if solid 

cancer of spleen is the 

primary disease)

FIIDOS

Stomach Stomach Wall FIIDOS

Testes and other male genitalia, including 

penis prostate, scrotum

Testes FIIDOS, Surrogate
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Table A1-1. Cross Reference of Diseased Organs, Tissues and Diseases

and Corresponding NTPR Standard Organs*(cont.)

Organ, Tissue, or Disease NTPR Standard Organ NTPR Standard 

Organ Type†

Thymus Thymus FIIDOS

Thyroid Thyroid FIIDOS

Upper large intestine, including appendix, 

cecum 

ULI Wall‡ FIIDOS, Surrogate

Urinary tract, urethra, ureter Urinary Bladder Wall Surrogate

* Based on Table Att 2-1 of SOP RA02.

† FIIDOS (in bold) means there are FIIDOS dose conversion factors (DCFs) for the organ(s) in bold. Surrogate 

means that DCFs for the NTPR Standard Organ are used for the non-bolded diseased organ(s).

‡ ET=extra-thoracic, ALL = Acute lymphocytic leukemia, AML = Acute myeloid leukemia, CLL=chronic 

lymphocytic leukemia, CML = chronic myeloid leukemia, LLI=lower large intestine, SI=small intestine, 

ULI = upper large intestine.
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Attachment 2.

Distributions and Deterministic Values of Model Parameters

for Internal Dose Assessments

The values of input parameters to the internal dose models provided in Table A2-1 of this 

attachment are default numbers that are applicable in most cases. They should be adjusted 

or replaced for cases where veteran-specific data is available. These default parameter 

values were estimated or derived in Weitz et al. (2009) and other technical basis 

documents listed in the references section of that document.

The column labeled “Nominal Value for Central Estimation” contains model input values 

that can be used to calculate the central (best) estimate of a dose. These values are usually 

based on documented observed data or best estimates, and were used in building the 

statistical distributions for each uncertain parameter. For numerically-generated 

distributions, such as GSMF, BR, f1, f2, AF100, etc., nominal values are the central 

estimates of those distributions, which are based on physical and mathematical models 

that characterize input parameters and their uncertainty and variability. Calculations of 

nominal doses provide point estimates using a dose reconstruction model with nominal 

values for all of its input parameters. In addition, nominal values are used as input 

parameters for model sensitivity analyses (Weitz et al., 2009). 
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Table A2-1. Distributions and Deterministic Values for Model Parameters

for Internal Dose Assessments

Parameter Definition Distribution for 

Probabilistic Analysis

Nominal Value for 

Central Estimation Deterministic*

SCENARIO PARAMETERS

Dates and Times of Arrival and Departure from Assigned Location

DateArrived Start date[time]

Triangular 

Example

min = Jun 19 [0000]

mode = Jun 19 [1200]

max = Jun 19 [2400]

Jun 19 [1200] Jun 19 [0800]

DateDeparted End date[time]

Triangular

Example

min = Jul 5 [0000]

mode = Jul 5 [1200]

max = Jul 5 [2400]

Jul 5 [1200] Jul 5 [2400]

INTERNAL DOSE (GENERAL)

Biasα Bias factors to adjust highsided inhalation DCF values

Assigned Constant

(see Weitz et al. [2009] 

Table 14)

ET region = 1.15

All other organs = 1.3 

Assigned Constant

(see Weitz et al. [2009] 

Table 14)

ET region = 1.15

All other organs = 1.3

1.0

Biasβγ Bias factors to adjust highsided inhalation DCF values

Assigned Constant

(see Weitz et al. [2009] 

Table 14)

1.35 for lung, breast, 

thymus, adrenals, spleen, 

liver, and pancreas

1.2 for all other organs 

Assigned Constant

(see Weitz et al. [2009] 

Table 14)

1.35 for lung, breast, 

thymus, adrenals, 

spleen, liver, and 

pancreas

1.2 for all other organs 

1.0

BR Breathing rate

Triangular distribution 

derived from USEPA 

(1997) data 

(see Weitz et al. [2009])

min = 0.33 m3 h

−1

mode = 1.53 m3 h

−1

max = 2.79 m3 h

−1

Mean of Distribution

~1.5 m3 h

−1 1.2 m3 h

−1

DCFInhα

DCFIngα

Uncertainty in inhalation and 

ingestion dose conversion 

factors for fallout α emitters

DCFs calculated with 

FIIDOS multiplied by 

Lognormal 

GM = 1.0 [Weitz et al. 

(2009)]

GSD = 7.91 (Kocher et 

al., [2009])

DCFs calculated with 

FIIDOS

(see Weitz et al. 

[2009])

DCFs calculated 

with FIIDOS

(see Weitz et al. 

[2009])
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Table A2-1. Distributions and Deterministic Values for Model Parameters

for Internal Dose Assessments (cont.)

Parameter Definition Distribution for 

Probabilistic Analysis

Nominal Value for 

Central Estimation Deterministic*

DCFInhβγ

DCFIngβγ

Uncertainty in inhalation and 

ingestion dose conversion 

factors for fallout β+γ 

radiation

DCFs calculated with 

FIIDOS multiplied by 

Lognormal 

GM = 1.0 (Weitz et al. 

[2009])

GSD = 4.05 (Kocher et 

al., [2009])

DCFs calculated with 

FIIDOS

(see Weitz et al. 

[2009])

DCFs calculated 

with FIIDOS (see 

Weitz et al. [2009])

FB

Film Badge Conversion 

Factor n/a 0.7 for planar source1.0 for facing a source

0.7 for planar source

1.0 for facing a 

source

INHALATION DOSE ABOARD SHIP

GSMF

Topside-averaged gamma 

source modification factor to 

adjust radiation intensity for 

sources that are not infinite 

planes

Calculated distribution 

based on ship type and 

dimensions.

(See Weitz [2010b])

Mode of Distribution

from probabilistic 

analysis

2

DESCENDING INHALATION DOSE†

AF100

Fraction of total airborne 

activity in fallout for 

particles less than 100 μm 

aerodynamic diameter

Triangular

(min, mode, max)

Calculate for Series and 

Shot

(See Weitz [2009])

Mode of Distribution 

from probabilistic 

analysis

1.0

f1

Faction of AF100 in Class 1 

sized (1–10 μm) particles

Triangular

min = 0

mode = 0.00136

max = 0.01

Mode of Distribution

0.00136 n/a

f2

Faction of AF100 in Class 2

sized (10–20 μm) particles

Triangular

min = 0

mode = 0.025

max = 0.1

Mode of Distribution

0.025 n/a

f3

Faction of AF100 in Class 3 

sized (20–100 μm) particles 1−(f1+f2) 1−(f1+f2) n/a

NR1

Fraction of Class 1 sized 

(1–10 μm) particles 

deposited in Region ET2 and 

cleared to digestive tract

n/a 0.4 n/a

NR2

Fraction of Class 2 sized 

(10–20 μm) particles 

deposited in Region ET2 and 

cleared to digestive tract

Lognormal

GM = 0.363

GSD = 1.106

Geometric Mean

0.363 n/a

NR3

Fraction of Class 3 sized 

(20–100 μm) particles 

deposited in Region ET2 and 

cleared to digestive tract

Lognormal

GM = 0.285

GSD = 1.139

Geometric Mean

0.285

n/a
DTRA / NTPR - Standard Operating Procedures Manual

ID01 –Doses to Organs from Intake of Radioactive Materials

Revision No.: 2.0

Date: April 30, 2021

Page 40 of 43

Table A2-1. Distributions and Deterministic Values for Model Parameters

for Internal Dose Assessments (cont.)

Parameter Definition Distribution for 

Probabilistic Analysis

Nominal Value for 

Central Estimation Deterministic*

R1

Fraction of Class 1 sized 

(1–10 μm) particles 

deposited in Regions BB, bb 

and AI

n/a 0.1 n/a

R2

Fraction of Class 2 sized 

(10–20 μm) particles 

deposited in Regions BB, bb 

and AI

Lognormal

GM = 0.0056

GSD = 1.744

Geometric Mean

0.0056 n/a

R3

Fraction of Class 3 sized 

(20–100 μm) particles 

deposited in Regions BB, bb 

and AI

Lognormal

GM = 0.001

GSD = 1.754

Geometric Mean

0.001 n/a

H0 Bottom of fallout cloud n/a 10,000 m 10,000 m

V1

Settling velocities for Class 1

sized (1–10 μm) particles

Logtriangular

min = 3.96 m h

−1

mode = 7.92 m h

−1

max = 1000 m h

−1

7.92 m h

−1 H0/time of arrival 

(m h

−1

)

V2

Settling velocities for Class 2

sized (10–20 μm) particles 

Logtriangular

min = 14.94 m h

−1

mode = 29.88 m h

−1

max = 1000 m h

−11

29.88 m h

−1 H0/time of arrival 

(m h

−1

)

V3

Settling velocities for Class 3

sized (20–100 μm) particles

Logtriangular

min = 234 m h

−1

mode = 468 m h

−1

max = 1000 m h

−1

468 m h

−1 H0/time of arrival 

(m h

−1

)

RESUSPENDED INHALATION DOSE (LAND-BASED PERSONNEL)

Fos

Fraction of time spent 

outside

Triangular 

min = 5/24

mode = 12/24

max = 18/24

0.5 (or 12/24) 0.6 

(or 14.4/24)

Ii

Relative intensity 

distribution of fallout while 

outdoors (i = 1) and indoors 

(i = 2) normalized to average 

intensity at the location

Log-normal

GM = 1.0

GSD = 1.5

(used with Fos)

1.0 1.0

K(t) Time-dependent 

resuspension factor

Lognormal multiplier of 

Equation 6

GM = 1

GSD = 4.05

Equation 6, or see 

Attachment 3 for 

values for surface

activities

Equation 5, or see 

Attachment 3 for 

values for specific 

activities
DTRA / NTPR - Standard Operating Procedures Manual

ID01 –Doses to Organs from Intake of Radioactive Materials

Revision No.: 2.0

Date: April 30, 2021

Page 41 of 43

Table A2-1. Distributions and Deterministic Values for Model Parameters

for Internal Dose Assessments (cont.)

Parameter Definition Distribution for 

Probabilistic Analysis

Nominal Value for 

Central Estimation Deterministic*

Kbw

Resuspension factor for 

fallout in blast wave region 

due to detonation effects

Log-normal

Respirable:

GM = 1.4 × 10−8

GSD = 25.6

Non-Respirable:

GM = 6.3 × 10−8

GSD = 21.7

Respirable:

Kbw = 1.410−8

Non-Respirable:

Kbw = 6.310−8

Respirable & NonRespirable:

Kbw = 110−4

Ktp

Resuspension factor for 

fallout in thermal-pulse 

region due to detonation 

effects

Log-normal

Respirable:

GM = 1.6 × 10−6

GSD = 9.23

Non-Respirable:

GM = 7.8 × 10−6

GSD = 7.22

Respirable:

Ktp = 1.610−6

Non-Respirable:

Ktp = 7.810−6

Respirable & NonRespirable:

Ktp = 110−3

INCIDENTAL INGESTION DOSE (LAND-BASED PERSONNEL)

qing Soil ingestion rate

Triangular

min = 0 to 10 mg d−1

mode = 50 to 100 mg d−1

Max = 400–500 mg d−1

100 mg d−1 500 mg d−1

ρsoil Soil bulk density

Triangular

min = 1.3 g cm−3

mode = 1.45 g cm−3

max = 1.6 g cm−3

1.45 g cm−3 1.3 g cm−3

* For deterministic dose models, high-sided (conservative) parameter values are selected to obtain upper-bound 

doses at least equal to the 95th percentile of a probability distribution. 

† AMAD particle size classes: Class 1 = 1–10 μm, Class 2 = 10–20 μm, Class 3 = 20–100 μm.
DTRA / NTPR - Standard Operating Procedures Manual

ID01 –Doses to Organs from Intake of Radioactive Materials

Revision No.: 2.0

Date: April 30, 2021

Page 42 of 43

Attachment 3.

Resuspension Factors for Typical Participant Activities in

Contaminated Areas

Table A3-1 of this attachment provides specific resuspension factors as a function of 

work activity used by NTPR for NTS- and PPG-based activities. These activity-specific 

resuspension factors are adapted from the Reactor Safety Study (USNRC, 1975) and 

listed in DNA (1986, Table 5).
DTRA / NTPR - Standard Operating Procedures Manual

ID01 –Doses to Organs from Intake of Radioactive Materials

Revision No.: 2.0

Date: April 30, 2021

Page 43 of 43

Table A3-1. Resuspension Factors for Typical Participant Activities in

Contaminated Areas

Participant

Category Activity ResuspensionFactor (m−l)

Observers & Maneuver Troops Touring display area after shot (on foot, or inside 

vehicle)

10−5

Troops involved in Helicopter, 

Armored Vehicles, and Tank 

Maneuvers and Operations in 

Contaminated Areas

Assaults or marches involving armored

vehicles, including tank occupants.

10−3

Maneuver Troops Involving

Helicopter Operations

Maneuvers involving helicopter

landings/take off

10−3

Assaults or marches involving armored

vehicles, including tank occupants

10−3

Crawl through open terrain 10−4

Dig foxholes, etc. 10−4

Ground assaults (no vehicle) 10−5

Trucking 10−5

Project Troops Dig out buried instrumentation/ equipment 10−4

Equipment/data recovery 10−4 –10−5

Decontamination projects (Bulldozing, etc.) 10−4

Visit project area (on foot or vehicle) 10−5

Support Troops

- Engineers/Ordinance Dig trenches, install/dismantle displays 10−4

- Communications Lay wire (communications network) 10−4

- Decontamination Equipment/personnel decontamination 10−4

- Transportation Trucking 10−5

- MP’s Traffic control, security sweep 10−5

- Rad-Safe Survey area on foot or from vehicle 10−5

Support Ships

Small Transport Boats

Normal operations for the first 100 hours 

following the end of fallout deposition 10−5

Decontamination (SOP Appendix B-5 and Case 

Number 341533) 10−4

CROSSROADS target ships Decontamination; disposal 10−5

Aircraft decontamination

personnel

Decontamination of active operations; aircraft 

returning from cloud sampling and tracking; and 

other aircraft decontamination

10−4