DNA 4747F 

/qj 6miw 

ANALYSIS OF RADIATION EXPOSURE 

FOR TASK FORCE WARRIOR 

SHOT SMOKY 

EXERCISE DESERT ROCK IZII-SZIU 

OPERATION PLUMBBOB 

Science Applications, Inc. 

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McLean, Virginia 22102 

31 May 1979 

Final Report for Period February 1978-February 1979 

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DNA 4747F 

4.TlTLE (and Strbfirfe) S. TYPE OF REPORT 8 PERlOD COVERED 

ANALYSIS OF RADIATION EXPOSURE FOR TASK FORCE Final Report for Period 

WARRIOR-SHOT SMOKY-EXERCISE DESERT ROCK February 1978-February 197 

PERFORMING ORG. REPORT NUMBER VII-VIII OPERATION PLUMBBOB 6SAI-79-794-WA 

7. AUTHOR(, 8 CONTRACT OR GRANT NUMBER(s) 

J. L. Goetz J. Klemm 

D. Kaul J. T. McGahan DNA 001-78-C-0186 

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Code B325078464 V99QAXNAlOOOl H2590D. 

19. KEY WORDS tConlinue on reverse szde if necessary end identify bv block number) 

SMOKY Plumbbob Infantry Troop Test 

Fallout NTPR Project 50.1 

Desert Rock Task Force WARRIOR 1st BG, i2th Inf. 

Radiation Exposure 

20 ABSTRACT {Continue on w-v~rse side if neressary and idrntrfy by bfock number) 

The radiation exposures to Task Force WARRIOR troops who participated in 

Shot SMOKY are determined and compared with film badge data gathered during 

Exercise Desert Rock VII-VIII. Fallout contours and decay rates are established and used to calculate total exposure, based on estimated stay time for 

various troop activities. Uncertainties are calculated for each parameter. 

Exposures are corrected to a film badge equivalent environment to permit 

DD , ;;,"';3 1473 EDITION OF I NOV 65 15 OBSOLETE UNCLASSIFIED 

SECURITY CLASSIFICATION OF TH,S PAGE (C)‘hen nnrs Entered) 
UNCLASSIFIED 

CURITY CLASSIFICATION OF THIS PAGEWhem Dale Entered) 

!O. ABSTRACT (Continued) 

:omparison with actual film badge readings. Total equivalent exposure is 

:alculated to be 480 mrem as compared with a 575 mrem mean film badge reading 

'or the entire operation. 

UNCLASSIFIED 

SECURITY CLASSIFICATION OF THIS PAGEW’hsn Dete Entered) 

- - _ ._-
- -- 

TABLE OF CONTENTS 

Section Page 

1 INTRODUCTION AND SUMMARY . . . . . . . . , . . . . . . . . 5 

2 OPERATIONS . . . . , . . . . . . . . . . . . . . . . . . , 9 

2.1 SHOTDATA ...................... 9 

2.2 PARTICIPANTS .................... 9 

2.3 TROOP MANEUVER PLAN ................. 10 

2.4 OTHER TROOP PLANS .................. 13 

2.5 PRE-SHOT OPERATIONS ................. 13 

2.6 SHOT SCENARIO .................... 20 

2.7 POST D-DAY OPERATIONS ................ 26 

3 INITIAL RADIATION 

3.1 SMOKY INITIAL RADIATION . . . . . . . . . . . . . . . 27 

3.2 DOPPLER INITIAL RADIATION . . . . . . . . . . . . . . 27 

4 RESIDUAL RADIATION .................... 43 

4.1 SMOKY RESIDUAL RADIATION .............. 43 

4.2 ESTIMATED RESIDUAL RADIATION EXPOSURE ........ 43 

5 UNCERTAINTY ANALYSIS AND DETERMINATION OF TOTAL EXPOSURE . 51 

5.1 RESIDUAL RADIATION EXPOSURE ............. 51 

5.2 INITIAL RADIATION EXPOSURE ............. 54 

5.3 TOTAL EXPOSURE ................... 56 

6 FILM BADGE DOSIMETRY ................... 57 

6.1 EXPOSURE CORRECTIONS TO FILM BADGE EQUIVALENCE ... 57 

6.2 FILM BADGE DATA ................... 57 

6.3 INTERPRETATION OF FILM BADGE DATA .......... 59 

7 CONCLUSIONS ....................... 69 

8 REFERENCES ........................ 73 

1 

I 
APPENDICES 

I FALLOUT PLOTS ..................... 77 

II FALLOUT DECAY ..................... 91 

III FILM BADGE DOSIMETRY ................. 101 

2 

- .-
- - - 

LIST OF FIGURES 

Figure Page 

1 Nevada Test Site ..................... 6 

2 General Scheme of Air Movement, Plans A and 8, Task 

Force WARRIOR ...................... 12 

3 Map of Phase I Defensive Positions ............ 14 

4 Typical Phase I Defensive Position ............ 16 

5 Landing Zone ECHO (looking north) ............ 18 

6 Landing Zone ECHO (looking west) ............. 19 

7 VIP Observers in Objective Area. ............. 23 

8 VIP Observer Area on Objective Pl ............ 24 

9 Task Force WARRIOR Positions, Shot DOPPLER ........ 28 

10 Measured and Calculated Neutron and Gamma Ray Exposure 

as a Function of Slant Range from Plumbbob Shot Doppler. . 31 

11 Best Estimate of Neutron and Gamma Ray Exposure as a 

Function of Slant Range from Plumbbob Shot Doppler 

with Comparison to Measurement .............. 32 

12 Energy Distribution of Quality Factor (QF) ........ 40 

13 Cross Plot of Film Badge Readings, by Period of Issue . . 60 

14 Distribution of Film Badge Readings for Each Period ... 61 

15 Observation of Shot SMOKY from News Nob ......... 63 

I-l BOLTZMANN Fallout .................... 81 

I-2 FRANKLIN Fallout ..................... 82 

I-3 WILSONFallout ...................... 83 

I-4 DIABLO Fallout ...................... 84 

I-5 KEPLER Fallout ...................... 85 

I-6 PASCAL "A" Fallout .................... 86 

I-7 SHASTA Fallout ...................... 87 

I-8 FRANKLIN PRIME Fallout .................. 88 

I-9 SMOKY Fallout ...................... 89 

II-1 Fallout Decay Comparison ................. 98 

III-1 DuPont Type 502 Film, Typical Response Curves. . . . . . . 102 

III-2 Typical Photon Response for Bare DuPont Type 502 Film 

Packet Showing Limits for Two Net Film Densities . . . . . 103 

III-3 Lexington Blue Grass Army Depot Pb-Sn Shielded Type 502 

Film Response Relative to Roentgen Response . . . . . . . 106 

III-4 The Adult Man Phantom . . . . . . . . . . . . . . . . . . 108 

111-5 Relative Spectral Structure of Fission Product Photons . . 110 

3 
- - -- 

LIST OF TABLES 

Table Page 

1 NEUTRON QUALITY FACTORS AS A FUNCTION OF ENERGY . . . . . . 39 

2 SUMMARY OF CALCULATED RESIDUAL RADIATION DOSE (mrem) 

FROM ACTIVITIES CONDUCTED IN CONNECTION WITH SHOT SMOKY . . 55 

3 COMPARISON OF DOSES AND FILM BADGE EQUIVALENCE WITH 

FILM BADGE DATA TASK FORCE WARRIOR TROOPS . . . . . . . . . 71 

I-l OPERATION PLUMBBOB FALLOUT DETERMINATION, 28 MAY to 

1 SEPTEFIBER 1957 . . . . . . . . . . . . . . . . . . . . . 78 

II-1 BOLTZMANN FALLOUT DECAY . . . . . . . . . . . . . . . . . . 92 

II-2 DIABLO FALLOUT DECAY . . . . . . . . . . . . . . . . . . . 93 

II-3 SHASTA FALLOUT DECAY . . . . . . . . . . . . . . . . . . . 94 

II-4 SMOKY FALLOUT DECAY . . . . . . . . . . . . . . . . . . . . 95 

II-5 PLUHBBOB COFIPOSITE FALLOUT DECAY . . . . . . . . . . . . . 96 

II-6 FACTORS TO CONVERT H+12 INTENSITIES TO INTENSITIES 

ore SPECIFIC DATES . . . . . . . . . . . . . . . . . . . . . 99 

4 
Section 1 

INTRODUCTION AND SUMMARY 

The story of Shot SMOKY is more than a chronology of events on 

31 August 1957. SMOKY planning began in the spring of 1957 and evolved 

into a complex troop operation intended to test and, more importantly, 

to demonstrate the ability of the U.S. Army to operate on the atomic 

battlefield. In late July, Camp Desert Rock, Nevada, became the "home 

away from home" for most of the troops who participated in the exercises 

that were planned around the SMOKY event, scheduled for 19 August. The 

briefings, orientations, planning, preparations, and staging were accomplished at the "Rock," over 35 miles from the SMOKY tower where the shot 

was to be detonated (see Figure 1). The major troop element was Task 

Force WARRIOR, a reinforced infantry company from the 1st Battle Group, 

12th Infantry, 4th Infantry Division. Leading up to the actual test, 

Task Force WARRIOR and supporting units engaged in several activities 

that would prepare them for the operation. Due to the shot postponements, 

other activities were added while some scheduled post-shot activities 

were deleted. Contingency planning proved crucial to the completion of 

the operation. 

The thrust of this report centers on the determination of 

Task Force WARRIOR radiation exposure from its activities in contaminated areas of the Nevada Test Site and the comparison of exposure estimates with dosimetry data. A discussion of task force objectives and 

the troop maneuvers planned to attain them provides background for the 

events that transpired. Task force activities are traced from rehearsals 

in early August through the operation on 31 August and follow-up tasks 

in order to provide the time-dependent position data required for an 

exposure analysis. Initial and residual radiation exposures from SMOKY 

and preceding shots are then calculated using both measured and derived 

intensities. The synthesis of decay rate and intensity data for 

fallout fields permits the dose rate at any position and time to 

5 















ground assault on Objective ZA, the southern end of Quartzite Ridge. 

At Objective P3, the platoon was approximately 4700 meters (2.9 miles) 

northwest of ground zero. 

Both the 2nd and 3rd Platoons remained on Objectives P4 and P3 

until they were relieved by the 4th Platoon. The platoons then began 

the ground assault of Objective 2. 

The third serial, consisting of the 1st Platoon, arrived at the 

airhead at 0718. It landed in two elements on high ground of Objective 

P2, overlooking Whiterock Spring, at the approximate elevation of 5100 

feet, and the high ground of Objective Pl, 1200 meters to the south, 

at elevation 4955 feet. The platoon remained at these locations, 5200-

5600 meters west of ground zero, until exercise termination at 0945. 

The fourth serial, the Weapons Platoon, arrived at LZ ECHO in 

two increments. The first increment landed at 0723 and the second increment landed at 0732. It may have moved slightly eastward after landing 

to support the assault of Objective 2, but likely remained in the general 

vicinity of LZ ECHO, 4600 meters from ground zero, until exercise 

termination. 

The Canadian Army Platoon arrived in the fifth serial. It landed 

on LZ HOTEL at 0740, 6000 meters WNW of ground zero. It then occupied 

Objective QUEEN, about 500 meters to the north, and the reconnaissance 

and security (R&S) positions on or near Twin Peaks, 1000-1500 meters 

to the north, at 0800. It remained in these positions, 6000-6600 meters 

NW of ground zero, until exercise termination. 

The sixth serial, consisting of the Reconnaissance Platoon, an 

engineer squad, and Patrols #6 and #7, landed some elements on or near 

the road west of Whiterock Spring at 0745. These units secured the road 

and occupied two southern R&S points overlooking the road, 6500 meters 

west of ground zero, until exercise termination. 

The seventh serial, consisting of the 4th Platoon and the medical detachment, landed at LZ ECHO at 0746. The medical detachment may 

have remained in this vicinity, while the 4th Platoon split into two 

21 
segments to relieve the 3rd Platoon on Objective P3 and the 2nd Platoon on Objective P4. The relief was complete by 0818. The platoon 

remained at these positions while the 2nd and 3rd Platoons assaulted 

Objective 2 on Quartzite Ridge. 

The eighth serial, the Mortar Platoon, arrived at LZ ECHO at 

0757. Three aircraft from this serial did not arrive until 0815, having 

landed initially at LZ HOTEL. It is unlikely that this platoon moved 

any significant distance from the landing site. Rather, it probably 

remained in the general vicinity of task force headquarters near LZ 

ECHO, where it emplaced its 4.2" mortars for the general support of 

the final assault on Objective 2. 

The ninth and last serial brought in the task force headquarters 

and the communications detachment. It landed at ECHO at 0814. Task 

force operations were controlled from this command post, established 

on the northern side of the landing zone, 5000 meters from ground zero, 

until exercise termination at 0945. 

It should be noted that several VIP observers were with TF 

WARRIOR at shot time and flew to the objective area early in the airlift to observe the landing operations and the securing of the airhead. 

Figures 7 and 8 show the observer area as being established near 

Objective Pl, where subsequent operations in LZ ECHO could be observed. 

Although there is no documentation to verify their arrival or their 

stay in the objective area, as many as 40 VIP observers may have 

observed the entire operation from this point, arriving with the first 

serial at 0715 and departing after exercise termination. 

The final assault on Quartzite Ridge (Objective 2) began at 

0830 after the 4th Platoon relieved the 2nd and 3rd Platoons on Objectives P4 and P3, respectively. The assault would have taken the platoons on a northeast azimuth that would have been no closer than 3500 

meters to ground zero for the 2nd Platoon, and 4500 meters for the 

3rd Platoon. The references state that the assault was halted at 

0915 by the authority of accompanying rad-safe personnel before the 

22 


objective was fully secured. The extent of fallout patterns, however, 

(Figure I-9) indicates that rad-safe criterion should not have been a 

factor in halting the advance, if the path of the assault was as 

planned. Because the planned path of direct assault would have encountered some very steep slopes, the assault may have rleviated to the 

south and east. This excursion could have led the 2nd Platoon toward 

the SMOKY fallout field where residual radiation levels !T,ere sufficient 

to cause rad-safe to halt the attack. The significance of this is 

discussed in Section 6.3.1. 

Immediately after transporting the task force to the objective 

area, the H-34 helicopters engaged in an aerial resupply mission from 

the aerial supply distribution point to the objective area. Three 

sling loads, totaling about 2% tons of water and simulated ammunition, 

were delivered between 0757 and 0818 hours on an automatic basis. An 

additional six tons were delivered at the request of the task force 

commander between 0829 and 0940, at which time all requests for additional supplies were denied in anticipation of the termination of the 

exercise. 

The exercise terminated at 0945 on order of the battle group 

commander. Although there is no documentation of the post-termination 

activities, the troops likely returned to the same points at which they 

were landed. Return to Camp Desert Rock could have been by helicopter 

to the truck loading area near the observation point, or the trucks 

could have been brought up to the landing zone. In either case, the 

VIP observers could have been evacuated by helicopter while the main 

elements of the task force reassembled in LZ ECHO and LZ HOTEL. Most 

of the task could have been evacuated by 1100 hours. It is likely that 

the headquarters, comma detachmenl, and medical detachment remained 

at LZ ECHO until the 2nd and 3rd Platoons returned from Objective 2. 

Their return was probably between 1100 and 1115, at which time muster 

25 
and equipment inventory would have been conducted. The entire area 

could have been evacuated by 1130 hours, although some of the supplies 

and slings may have been left for subsequent recovery on D+l. 

2.7 POST D-DAY OPERATIONS 

On D+l, a recovery party consisting of Camp Desert Rock personnel 

and helicopter battalion personnel flew into the objective area for the 

purpose of obtaining the slings and water cans that had been delivered 

to the task force during Phase III of the troop exercise. This effort 

would have required three helicopters and their crews, plus about 15 

troops, to search the objective area, to load the slings, and to accomplish the hook-up. Approximately three hours would have been devoted 

to this exercise, two of which would have been in the objective area. 

A necessary element of the exercise was the inspection of the 

Phase I defensive positions to determine the effects of the shot. This 

inspection was scheduled for D-Day or D+l (Reference 4). There is no 

time or date record of this activity. Because of the possible high 

levels of contamination on these positions, a minimum one-day delay 

would have been required to permit the fallout contamination to decay to 

safe levels. On SMOKY D+2, Shot GALILEO was fired. Its northerly 

fallout would have restricted movement in the northern sector of Yucca 

Flat on 2 September. Film badges were turned in on 2 September. Hence, 

inspection of the defensive positions is assumed to have occurred on 

1 September. The inspecting party, consisting of selected personnel from 

Task Force WARRIOR, likely flew to the general area by helicopter and 

remained on the ground for approximately two hours to record the damage 

to the positions and to recover weapons and equipment. Two helicopters 

and about 15 personnel would have been necessary for this effort. 

26 
Section 3 

INITIAL RADIATION 

3.1 SMOKY INITIAL RADIATION 

Because the expected fallout necessitated the execution of Plan 

B, no observers were in the SMOKY trenches. Observers for Plan A would 

have consisted of the Provisional Company, 82nd Airborne Division 

(TF BIG BANG), plus approximately 50 VIP observers. For Plan B, TF BIG 

BANG witnessed the SMOKY event from News Nob while the VIP observers 

witnessed from the TF WARRIOR area, approximately eight miles from 

ground zero. The limit of 1 roentgen exposure extended to less than 

two miles (Reference 7). Thus, no initial radiation, defined as that 

radiation occurring within the first minute after burst, was received 

by any of the participants in the SMOKY event. 

3.2 DOPPLER INITIAL RADIATION 

Neither observation of SMOKY, nor of other Plumbbob shots from 

News Nob, resulted in accrual of initial radiation exposure. However, 

on 23 August, Task Force WARRIOR observed Shot DOPPLER from a trench 

system constructed on a line normal to a radius from ground zero at 

horizontal ranges between 2800 and 2900 meters. Figure 9 shows the 

shot area as well as the trench area used by the troops. Personnel 

of Task Force WARRIOR were exposed to both neutron and gamma initial 

radiation. This occurred in spite of the protection afforded by the 

trenches and was due primarily to the scattering of the radiation in 

the air above the trenches. 

Estimation of personnel exposure in the trench system has been 

accomplished in two parts. First, the intensity and angular and 

energy-differential character of the neutron and gamma radiation 

immediately above the trench system were determined. Second, the 

radiation field above the trench system was used as a source to determine the exposure within the trenches themselves. 

27 
- - 

! 

i 

I 

I 

PI 

t-cbund 

i 

; 

0 

1 

500 

, 

Meters 

1000 

I ~___.._.._____ _. 

45 

28 

46 

I 

Figure 9. 

Task Force WARRIOS 

Positions, Shot DOPPLER 

23 August 1957 
The character of the neutron and gamma radiation fields produced by Shot DOPPLER was affected by the following parameters: 

Blast Yield 11 kt 

Height of Burst 457 m 

Delta Elevation (GZ-Trench) 30 m 

Effective Air Density 1.009 x 1o-3 g/cc 

(Reference 9, 24) 

Hydrogen Content of Dry Area 7 Soil 1.00 x 10m2 atom/b.cm 

(Reference 25) 

Humidity (Relative) 48% at 22'C 

(Reference 28) 

Radiation field intensity and other characteristics were determined 

from these parameters for a location immediately above the trenches, 

using measured radiation fluence and dose data (Reference 8, 9) and 

the computer codes ATR4 (Reference 20) and ATR4.1 (Reference 26). 

These codes are data handling routines which contain the results of 

state-of-the-art calculations of neutron and gamma ray transport 

through infinite homogeneous dry air. They also contain factors for 

the adjustment of integral quantities, such as free-in-air tissue dose*, 

to correct for the presence of the qround. Gritzner et al. (Reference 27) 

have shown that the qround's hydrogen content has a si9nificant effect on 

the propagation of neutron and neutron-induced gamma free-in-air dose. 

The data base used to prepare the ground correction factors for ATR4 

has been generated using the hydrogen content of average Nevada soil 

(9.77 x lo-3 atom/b.cm), which is very similar to that of Area 7. 

Therefore, ATR4 was used to calculate the neutron and neutron-induced 

dose components for DOPPLER. An adjustment for the small remaining 

difference in soil hydrogen content was made according to the method 

and data presented by Gritzner, et al. (Reference 27). No similar 

* The term free-in-air (FIA) tissue dose refers to the amount of energy 

absorption (in rads) in a small sample of tissue located at the point 

of interest. One rad is the deposition of 109 ergs of energy in one 

gram of the material of interest (tissue in this case). 

29 
compendium exists for adjusting transported neutron free-in-air dose 

values for variations in relative humidity. Omission of such adjustment will cause ATR4 to overpredict such dose values to an undetermined, 

but probably small degree. Prompt gamma ray and debris gamma ray 

fields are not sensitive to soil hydrogen content. Therefore, ATR4.1, 

which contains fully energy differential ground correction factors 

calculated for drier ground (1.75 x 10-j atom/b.cm hydrogen), was 

used to calculate these components. 

Calculated neutron and gamma ray integral intensities 

for Shot DOPPLER are shown in Figure 10, along with the results of 

neutron and gamna ray field measurements made at that event. Qualitatively, the agreement between calculated and measured values is quite 

good. In particular the slopes of calculated and measured neutron FIA 

dose values are well matched, indicating that the source spectra and 

ground hydrogen content used in the calculation are appropriate. 

However, the calculated neutron FIA dose consistently exceeds the 

measured value by approximately 35%. Since the probable uncertainty 

in the total neutron output of the device as used in the calculation 

probably exceeds that of the fluence field measurements, a best estimate of the FIA dose distribution for Shot DOPPLER has been obtained 

by normalizing the calculated neutron and neutron-induced gamma ray 

FIA dose using the neutron FIA dose values as interpreted from the 

measured fluences. The best estimate values are shown in Figure 11. 

Both the gamma ray and neutron calculated FIA dose values agree very 

well with the measured data. The good agreement between measured and 

calculated gamma ray FIA dose lends extra credence to the adjustment 

of neutron values. 

The fully adjusted calculated values for FIA dose 1 meter 

above the trench locations are shown in the following table. 

30 
LEGEND 

Neutron measured A 

Exposure calculated 

Gamma Ray measured @ 

Exposure calculated ----I 

lOI c 1 

500 1 IO - 1 3 1 30

Slant Range (m) 

Figure 10. Measured and Calculated Neutron and Gamma Ray Exposure as 

a Function of Slant Range from Plumbbob Shot DOPPLER. 

31 
I I I 

LEGEND 

Neutron measuredA 

Exposure calculated 

Gamma Ray measured 0 

Exposure calculated I-I-I 

Figure 11. 

----d 

1000 -15 3 2.700 

Slant Range cm) 

Best Estimate of Neutron and Gamma Ray Exposure as a Function 

of Slant Range from Plumbbob Shot DOPPLER with Comparison to 

Measurement 

32 

_ 
Mean 

(Middle Trench) Front Trench Back Trench 

Slant range (m) 2891 2842 2941 

Neutron Rad (FIA) .099 .125 .078 

Gamma Rad (FIA) 1.24 1.40 1.12 

As a check on the neutron values the measured neutron fluences were 

extrapolated using a semi-log fit to the r2 fluence. The dose obtained 

by the approximation is .091 rad, which is in good agreement with the 

calculated value. The calcu lated value has been chosen as the FIA 

dose of record because it is considered to be the result of a more 

physically realistic method of extrapolation than the simple semi-log 

fit. However, the close agreement of the two values indicates that 

the uncertainty in the calculated value is probably on the same order 

as that of the measured data to which it is normalized (+25%). 

The same test cannot be applied to gamma ray dose FIA values 

since it is well known that in the presence of neutrons such values 

do not behave as described by a strict semi-log fit. However, at the 

trench location the dominant gamma ray component is that generated by 

the neutrons. Therefore, it is unlikely that the uncertainty in the 

gamma ray FIA dose value exceeds ?50%, i.e., twice the neutron component 

uncertainty. 

The energy and angle dependence of neutron fluence and gamma 

ray exposure have been estimated using a number of sources. First 

the energy dependence of the neutron fluence was estimated by extrapolating the measured fluences and normalizing the result using the 

integral FIA dose value (.099 rad(tis) @ 2891 m). The spectrum thus 

obtained is: 

33 
Neutron fl uence (n/cm2) 

Neutron Energy Range at slant range = 2891 m 

Thermal (10-l’ to 3.00 x lo-leV) 2.22 x 107 

Epithermal (3.00 x lo-'eV to 10 keV) 6.80 x 107 

Fast (.OlO to .63 FleV) 1.56 x lo7 

(.63 to 1.5 MeV) 8.r35 x lo6 

(1.5 to 3.0 MeV) 5.03 x lo6 

,' 3.0 MeV 1.19 x lo7 

TOTAL 1.31 x lo8 

The epithermal component was taken to be 52% of the total fluence as 

suggested by R. J. Smith et al. (Reference 9). Angular dependence of 

the neutron fluence was estimated using data reported by Straker (Reference 30). These indicate that, 1500 m from a bare fission source placed 

at 15 m above the ground, the downward directed components of the neutron 

fluence 1 meter above the ground are 

Energy % Downward Directed Fluence 

Thermal 35 

Epithermal 50 

Fast (>.63 MeV) 71 

The gamma ray spectrum was approximated by that of the combined 

prompt and neutron-induced components, transported through infinite 

homogeneous air. 

Gama Ray Fl uence (v/cm2) 

Gamma Ray Energy Range (MeV) at slant range = 2891 m 

2 x 1o-2 to 1 x 10-l 1.08 x 10’ 

1 x 10-l to 2 x 10-l 6.26 x lo8 

2 x 10-l to 4 x 10-l 3.18 x 10’ 

4 x 10-l to 8 x 10-l 2.40 x 108 

8 x 10-l to 1.0 5.55 x lo7 

1.0 to 2.0 1.79 x lo8 

2.0 to 4.0 2.19 x lo8 

4.0 to 10.0 3.50 x lo8 

34 
The gamma ray fluence angular dependence has been estimated using the 

DOPPLER geometry and the directional gamma ray dose calculated in 

infinite homogeneous air. Directional dose was used in order to weight 

most heavily that portion of the fluence producing the greatest dose. 

On this basis, approximately 54% of the total fluence was downwarddirected. 

All the above energy spectra and downward-directed components 

are merely estimates. No specific differential measurements or calculations have ever been performed for the combination of source characteristics and geometry of interest here. Consequently it was postulated 

that for both gamma rays and neutrons, the downward-directed component 

was spread uniformly over the lower 2~ steradians. This treatment provides an upper limit for the dose in the trench. Any distribution of 

radiation peaked in the direction away from the shot would reduce the 

fluence into the trench. 

Two methods have been chosen to characterize the radiation 

intensity within the trench. First, film badge reading equivalent 

values were calculated, using the response (energy differential sensitivity) of the SnlPb shielded DuPont Type 502 film badge in use at the 

time (References 13, 15). Calculations were performed using the MORSE 

Monte Carlo radiation transport code (Reference 22) together with a 

man phantom model developed previously for the Defense Nuclear Agency 

(see Appendix III). Troops in trenches are assumed to have remained 

at least 2 ft below the surface, in accordance with the SOP outlined 

in Reference 3. Thus, for the purpose of establishing a representative 

film badge equivalent reading for personnel within the trench the man 

phantom was positioned in a crouching position with its back 2 ft 

below the lip of the trench. This corresponds to a man of the size 

of the phantom bent 90' at the waist and standing in a 5 ft deep trench. 

This depth is consistent with the minimum trench depth cited in 

Reference 3. In order to gain some appreciation for the effect of 

position on the calculated badge reading equivalent value, calculations 

were also performed for the phantom upright, facing the length of the 

35 
trench. In that case the phantom's head extends to within 14 in. of 

the trench lip, which violates the SOP. However, this position does 

allow the badge on the phantom's chest to remain at the same depth 

relative to the lip of the trench (2.6 ft), thereby permitting direct 

comparison of badge readings for body orientation effects. The average 

torso depth within the trench is expected to have been within six inches 

of that specified. Calculated film badge reading equivalents are: 

Representative Film Badge Reading (rem) 

Badge Reading (rem) for for Upright 

Personnel Following SOP Phantom _ 

Gamma Ray .130(.12)* .158(.12) 

Neutron-Induced Gamma Ray .003(.31)) .002( 151 

TOTAL . 133 .160 

* Values in parentheses are fractional deviations of Monte Carlo Calculations. 

Neutron-induced gamma radiation includes that produced in the walls of 

the trench and in the man himself. The contribution from direct neutron 

interaction with the badge is on the order of lr) percent of the neutroninduced gamma ray component and is hence neglected. The total value of 

133 mrem has been chosen as the best estimate of the film badge reading 

equivalent of the Task Force WARRIOR exposure to initial radiation 

while observing Shot DOPPLER. 

Actual exposure to individuals is difficult to characterize 

because of variations in protection afforded by increasing trench 

depth. Therefore, in addition to the film badge reading equivalent 

data presented above, exposure in terms of rad free-in-air for 

both neutrons and gamma rays have been calculated as a function of 

depth in an empty trench (L = 10 ft, W = 2 ft, D = 5 ft). These values 

are: 

36 
Dose (Rad FIA) 

Neutron-Induced 

Depth (ft) Neutron Gamma Gamma 

1.0 .050 (.09)* .004 (.40) .430 (.07) 

2.33 .020 (.lO) .003 (.40) .225 (.09) 

4.0 .012 (.17) .002 (.50) .115 (.12) 

* Values in parentheses are fractional standard deviations of 

Monte Carlo Calculations. 

The 2.33 ft location corresponds to that of the midline of the torso 

of the man phantom in the representative personnel position described 

above. Therefore, the ciose at this depth has been chosen to represent the actual exposure of Task Force WARRIOR personnel. Of course 

extremities extending above this depth would receive a higher dose 

while the lower extremities would receive less. 

Available data, such as those summarized in the report, 

"Radiobiological Factors in Planned Space Flight" (Reference 29) and the 

later "Biological Effects of Ionizing Radiation (BEIR) Report" (Reference 31), indicate that there is a difference in the biological consequences between radiation with high energy transfer per unit path 

length (LETpand that with low LET. The heavy charged particles set 

in motion by neutron interactions are attributed a high LET. The gamma 

rays and the electrons that the neutrons set in motion have relatively 

low LET value. The measure of this overall effect is the relative biological effectiveness (RBE) of the radiation, which uses as a standard 

X-rays of approximately 250 keV energy. The RBE for gamna rays is 

commonly accepted as unity. 

The available data on RBE for neutrons are sparse. However, 

they indicate that RBE values vary with radiation intensity and type 

of effect of interest as well as with LET. Because of this the term 

RBE has come to possess a large degree of ambiguity and even when 

properly defined has an uncertain value. Therefore, for the purpose 

* LET is the abbreviation for "linear energy transfer." 

37 
of radiation protection,the neutron RBE has been replaced with the 

quality factor (QF). The National Comm ittee for Radiation Protect ion 

(NCRP) (Reference 21) defines the QF as follows: 

quality factor (QF): A factor which is used in radiation protection to weight the absorbed dose with regard 

to its presumed biological effectiveness insofar as it 

depends on the LET of the charged particles. The quality 

factor is a function of the LET of the charged particles 

that deliver the absorbed dose. The charged particles 

traversing irradiated matter usually have a range of 

values of LET in which case the term then refers to the 

weighted average quality factor. 

The QF has been calculated as a function of neutron energy and 

is presented in Table 1. Note that for the energies of interest, the 

QF can vary from 2 to 11. For the purpose of this study these point 

energy data have been converted into the energy group average data in 

Figure 12 and collapsed further into the energy groups as follows: 

QF Energy Range 

2.0 Thermal (<.3eV) 

2.1 Epithermal (.3eV < E cl0 keV) -

8.0 Fast (.OlO f. E c 0.63 MeV) 

10.7 (0.63 < E < 1.5 MeV) 

9.7 (1.5 5-E < 3.0 MeV) 

7.9 (1 3.0 MeV) 

Dose equivalent values (in rem) given in this report have been 

calculated as recommended by NCRP, using the above quality factor data 

as follows: 

rem = 

c pi x Ki X QFi 

i 

33 
Table 1. Neutron Quality Factors As A Function of Energy 

Neutron Energy QF 

HeV 

2.5 x 1o-8 

1 x 1o-7 

1 x lo+ 

1 x 1o-5 

1 x 1o-4 

1 x 1o-3 

1 x 1o-3 

1 x lo-* 

1 x 10-l 

5 x 10-l 

1 

2.5 

5 

7 

10 

14 

20 

40 

60 

1 x 102 

2 x lo* 

3 x 102 

4 x lo* 

Source: Reference 21 

2 

2 

2 

2 

2 

2 

2 

2.5 

7.5 

11 

11 

9 

8 

7 

6.5 

7.5 

8 

7 

5.5 

4 

3.5 

3.5 

3.5 

39 
-

N 'm 

z 

. 
where the dose in rem is equal to the sum over all energy groups i of 

the product of the fluence $ (n/cm*), the Kerma factor K (rads/(n/cm*)) 

and the Quality Factor QF (rem/rad) for each energy group. The overall 

average quality factor may be determined as follows: 

For the neutron environment immediately above the mean DOPPLER trench 

location, QF = 8.6. At a depth of 2.33 feet in the trench, the quality 

factor is close to the maximum. These values may be compared with the 

value of 5 given by the BEIR committee as an estimate of the RBE for 

neutron-induced leukemia based on the Japanese atomic bomb survivors. 

The BEIR RBE estimate is based on relatively high neutron doses, 

i.e., between 1 and 100 rads, and reasonably uniform exposure across 

the extremities. In the case of DOPPLER personnel the neutron exposure 

was low, in the range of 10 -* to 10-l rad and extremely nonuniform. 

At these low dose levels the studies of Katz (Reference 32) indicate 

that the neutron RBE for any specific biological effect may be an order 

of magnitude or more greater than it is in the high dose range. However, 

this is postulated on the basis of an apparent decrease in the effectiveness of the gamma rays relative to that of neutrons with decreasing 

dose levels. On the other hand, the nonuniform nature of the exposure 

may serve to reduce the total neutron interactions in the body by a 

large amount, thus offsetting the increase in RBE. Given this uncertainty as well as the interest in mar;y radiation effects attendant to 

the WARRIOR exposure, results reported here are limited to exposure 

values in rad(tis) free-in-air and rem free-in-air, the latter being 

based on the uniquely definable, dose level independent, LET dependent 

approach set forth by NCRP. The in-trench dose in rem is as follows: 

41 
- - _ - 

Dose (rem-FIA) 

Neutron-Induced 

Depth (ft) Neutron Gama Gamma Total 

1 .411(.09)* .004(.40) .430(.07) .845 

2.33 .227(.10) .003(.40) .225(.09) .455 

4.0 .122(.17) .002(.50) .115(.12) .239 

*Values in parentheses are fractional standard deviation of Monte 

Carlo Calculations. 

Note that the film baage reading equivalent value of 133 mrem calculated 

earlier accounts for less than one-third of the 455 mrem exposure at 

nominal trench depth. This is because of body shielding and the fact 

that the film badge is insensitive to direct neutron exposure. 

42 

-
Section 4 

RESIDUAL RADIATION 

4.1 SMOKY RESIDUAL RADIATION 

The SMOKY fallout pattern generally followed the meteorological 

predictions. Lower segments of the cloud were seen to drift slowly to 

the southeast while the cloud top rose to above 35,000 feet and drifted 

due east at about 43 knots. Both the on-site (close-in) and off-site 

radiological measurements confirmed the visual observations. The Plan 

A observer area, the trench line and the infiltration course, none of 

which were used due to the expected fallout drift, were directly in the 

path of the cloud (Figure I-9). The levels of contamination at the 

infiltration course, 3400 meters SSE of ground zero, and the trenches, 

4400 meters from ground zero, were on the order of 100 r/hr at H+l. 

Obviously, any occupation of the trench or infiltration course areas 

would have resulted in extremely high exposures. Thus, the decision 

not to use Plan A and the SMOKY trenches was indeed a sound one. 

4.2 ESTIMATED RESIDUAL RADIATION EXPOSURE 

The 14 shots prior to SMOKY, as well as SMOKY itself, are 

listed in Appendix I, Table I-l. The table notes that five shots 

produced insignificant fallout and one (Priscilla) resulted in fallout 

in the Air Force Gunnery Range to the east. Fallout from all others is 

depicted in the appropriate figures referenced in the table. Ground 

zeros for these shots are shown in Figure 1. It can be assumed that 

virtually any entry into the forward area, particularly the northern 

end of Yucca Flat, would have resulted in residual radiation exposure 

from previous shots. Accordingly, every Task Force WARRIOR activity 

conducted in the forward area is examined. For ease of analysis, the 

activities related to SMOKY are grouped as follows: 

- Rehearsals of Phase II and Phase II Operational Plans, 

5-9 August 

43 
- Preparation and inspection of Phase I Defensive Positions, 

12-14 August 

- Observation of Shot SMOKY, 31 August 

- Execution of Phase II and Phase III exercises, 31 August 

- Resupply equipment recovery, 1 September 

- Post-shot inspection of Phase I Defensive Positions, 

1 September 

For each of the above activities, the radiation fields encountered 

during the activity are now examined. 

4.2.1 Rehearsals 

The rehearsals of operational plans for Phase II and Phase III 

of the Infantry Troop Test were accomplished during the week of 5-9 

August 1957 (discussed in Section 2.5). The loading areas for both 

Plan A and Plan B were used in the airlift of Task Force WARRIOR to 

both the primary and alternate objective areas. Of the four possible 

variations of the airlift maneuver, two would have included the ground 

assault field exercise in the primary objective area. The Phase III 

resupply rehearsals were conducted in conjunction with the first two 

troop operation rehearsals. For the rehearsals, Task Force WARRIOR 

would have spent one to two hours (depending on the serial) in each 

helicopter loading area before boarding the helicopters for the lift 

to the objective area. Some four hours would have been required for a 

full-scale rehearsal in the primary objective area before evacuation 

back to the loading area, where ground transportation was waiting. Two 

hours in the alternate objective area for each rehearsal would have 

sufficed for this variation. 

Fallout patterns from the following six shots could have impacted 

the rehearsal areas. They are now examined to determine their possible 

contribution to the radiation dose received during all the rehearsals 

of operational plans. 

BOLTZMANN (28 May) 

FRANKLIN (2 June) 

44 
WILSON (18 June) 

DIABLO (15 July) 

KEPLER (24 July) 

PASCAL "A" (26 July) 

The fallout patterns for these shots are shown in Figures I-l through 

I-6, Appendix I. 

The BOLTZMANN fallout (Figure I-l) impacted in the Plan A 

loading area, used for two task force rehearsals during 5 to 9 August. 

It also impacted on the primary objective area. From the decay conversion factors shown in Table 11-6, the BOLTZMANN fallout intensities, 

adjusted to 7 August, were approximately .04 mr/hr (10 x .004) in the 

Plan A loading area and in the primary objective area. This is considered insignificant and need not be evaluated further. 

The FRANKLIN fallout (Figure I-2) may have impacted on the Plan 

A loading area. Because this shot was a misfire, however, the H+12 

intensity at Balloon Hill was probably no higher than 1 mr/hr. The 

decay conversion factor shown in Table II-6 is .004. The FRANKLIN 

fallout intensity at Balloon Hill, adjusted to 7 August, is insignificant and need not be considered further. 

The WILSON fallout (Figure I-3) impacted on the helicopter 

loading areas for both Plan A and Plan B. From the decay conversion 

factors shown in Table 11-6, the WILSON fallout intensities, adjusted 

to 7 August, were approximately .03 mr/hr (5 x .006) in the Plan A 

loading area and .06 mr/hr (10 x .006) in the Plan B loading area. 

These intensities are insignificant for the stay times involved and 

need not be considered further. 

The DIABLO fallout pattern (Figure I-4) impacted on both the 

primary and alternate objective areas for the troop maneuver. From 

the decay conversion factors shown in Table 11-6, the DIABLO intensities around 7 August were less than 1 mr/hr (cl0 x .Oll) and about 3 

mr/hr (300 x .Oll) in the primary and alternate objective areas, respectively, during exercise rehearsals. For the assumed stay time of two 

hours on each occasion in the alternate objective area, the estimated 

accrued exposure is 12 mrem. 

45 
KEPLER produced a fallout pattern (Figure I-5) that impacted on 

the troop loading area for Plan B, used for two rehearsals. From the 

decay conversion factors shown in Table 11-6, the KEPLER fallout intensity, adjusted to 7 August, was approximately 5 mr/hr (ZOO x .027). 

Assuming a total stay time in the loading area of 2 hours for each 

rehearsal, the task force would have accrued an exposure of 20 mrem 

during 5 to 9 August in the KEPLER fallout field. 

PASCAL "A" was a safety shot with some nuclear yield. The fallout was in the direction of Balloon Hill, but was sufficiently localized 

that it is extremely doubtful that any significant fallout reached the 

Plan A loading area. This is evidenced by inspection of Figure I-6. 

No further evaluation of this dose is necessary. 

4.2.2 Defensive Positions 

The Phase I defensive positions were prepared on 12 and 13 

August, and inspected on 14 August. The task force spent 12 hours in 

the preparation and inspection of these positions, as well as in moving 

to and from the specific positions and the ground transport vehicles. 

The total exposure is determined by the technique described previously. 

Inspection of dose rate contours shows that Shots BOLTZPIANN and DIABLO 

contributed to the fallout intensity in the defensive position area. 

The following chart shows the factor used to convert each intensity 

(D in mr/hr) to 13 August, as well as the estimated exposure of the 

task force for the period 12-14 August: 

. 

Shot D12 f D (13 August) Dose (mrem) -

BOLTZMANN 300 .004 1.2 14 

DIABLO 2400* .009 22 260 

* 

For those positions prepared closer to the hot line, 

this rate could have been 30 percent higher. 

This would apply particularly to positions l-22 

(Figure 3). 

46 
4.2.3 Shot SMOKY 

Task Force WARRIOR witnessed Shot SMOKY from the Plan B observation area on 31 August. They arrived at the observer area at approximately 0330. The stay time, until the troops boarded the helicopters for 

airlift to the objective area, was 34 to 4% hours. Inspection of all 

significant fallout contours shows that Shots WILSON and KEPLER contributed to the residual intensities in the observer area. The earlier 

discussion of the WILSON contribution showed it to be insignificant 

for the exercise rehearsals; hence, at times subsequent to the rehearsals, 

the intensity remains insignificant. The KEPLER fallout, shown in 

Figure I-5, had an H+12 intensity of 1000 mr/hr at the observation 

location on the north slope of the high ground, coordinates 760046. 

Using the conversion method described previously, the KEPLER H+12 

intensity corresponds to an intensity of 8 mr/hr (1000 x .OOS) on 

31 August. A stay time of approximately 4 hours yields a total estimated exposure of 32 mrem to Task Force WARRIOR personnel while observing Shot SMOKY. The troops received no radiation exposure from SMOKY 

itself during the observation phase. 

4.2.4 Troop Maneuvers 

The troop maneuver in the primary objective area on 31 August 

was discussed in detail in Section 2.6. The fallout from Shots BOLTZMANN, 

DIABLO, and SHASTA impacted on the primary objective area. The wind 

patterns on 31 August were such that fallout from SMOKY itself did not 

impact the maneuver area, as can be seen from Figure I-9. The fallout 

patterns from BOLTZMANN and DIABLO (Figures I-l and I-4) were examined 

previously to determine the dose accumulated during the exercise 

rehearsals. SHASTA occurred on 18 August and FRANKLIN PRIME on 30 

August, subsequent to the rehearsals. Their fallout plots are shown 

in Figures I-7 and I-8. Using the decay rates shown in Table 11-6, 

the H+12 intensities are converted to 31 August. The following chart 

shows the conversion factors as well as the total estimated exposure 

of the maneuver elements for the period of the exercise. 

47 
. Task Force nose 

Shot 

D12 

f 

-

0 (31 Aug) 

- (mrem) 

BOLTZllANN 10-100 .003 .3 r\legl. 

DIABLO 10 .005 .05 Negl. 

SHASTA 1000 .033 33 116 

FRANKLIN PRIME Negl. - - Negl. 

The above exposures are based on an averaqe stay time in the objective 

area of 3.5 hours for the task force. The calculations could be refined 

to provide exposures for each platoon-sized element, but such refinement is beyond the scope of the data reliability. The two platoons 

that assaulted Quartzite Ridge were moving toward the SHASTA hot line 

as well as that of the older DIABLO field. Their exposures could have 

been some 20 percent higher than the 116 mrem received by the main 

body of troops. 

4.2.5 Equipment Recovery 

The equipment recovery, assumed to have been accomplished on 

1 September, is not documented. As discussed earlier, only a few 

helicopters and accompanying task force personnel would have been 

required to recover slings, water cans, and related matter. Because 

there is no way to identify the personnel involved in this activity, 

the exposure is not ascribed to the task force as a whole. The estimated exposure of 56 mram is obtained from the H+12 SHASTA plot 

(Figure I-7), the conversion factor from Table 11-6, and a stay time 

of two hours (1000 x .028 x 2). SMOKY itself did not contribute to 

this exposure. 

4.2.6 Defensive Positions 

The inspection of the Phase I defensive positions by selected 

personnel is assumed to have occurred on 1 September 1957, as described 

previously. The stay time of two hours is applied to the fallout 

fields of the four shots that contributed to the residual radiation 

in the area of the defensive positions, using the decay conversion 

48 

-
factors from Table 11-6. Of the four shots, SHASTA and SMOKY occurred 

subsequent to the preparation of the positions. Their H+12 intensities 

are 700 and 50 mr, respectively (Figures I-7 and I-9). The chart 

below shows the estimated exposure of selected task force personnel 

during this activity. 

. 

Shot D12 f- D (1 Sept) Jose (mrem) 

BOLTZMANN 300 .003 1 2 

DIABLO 2400 .005 12 24 

SHASTA 700 .028 20 40 

SMOKY 50 .50 25 50 

49 
50 
Section 5 

UNCERTAINTY ANALYSIS AND DETERMINATION OF TOTAL EXPOSURE 

Because of the uncertainties of the parameters used in calculating the partial exposures in Sections 3.2 and 4.2, a rigorous treatmetit of all the sources of error is required. After the uncertainties 

are determined, the total exposure of Task Force !;IARRIORcan be assessed. 

5.1 RESIDUAL RADIATION EXPOSURE 

Determination of the residual radiation exposure for Task Force 

WARRIOR (made independently of film badge data) has the following sources 

of error: (1) fallout plot intensities, (2) location of a troop activity, (3) fallout decay rates, (4) troop arrival time at an activity, 

and (5) duration of an activity. These arise because residual radiation exposure, as calculated for each troop location or activity, is 

the product of the exposure rate (normalized to H+12) as a function of 

position; decay (since H+12) as a function of time; and duration (stay 

time) at a given position. 

For purposes of comparison and calculation, errors are expressed 

as multiplicative factors which arise from the exponential character of 

decay rates and fallout field intensity variations. All are expressed 

in terms of a 90 percent confidence limit. 

As discussed in Appendix I, the fallout plot intensities have 

an error factor of 1.46 in the region in which data was collected. Error 

in the interpolated region between on-site and off-site data points cannot be as precisely assessed. There, error estimates are based on what 

variation in fallout level would result from shifting the interpolated 

(dashed) contours to the estimated limit of consistency with on-site and 

Program 37 contours. Fallout intensities between contours are computed 

by logarithmic interpolation, except across the hot line, where the 

Gaussian fit of Appendix I is applied. 

51 
The position of an activity may be imprecisely known owing to a 

dearth of documentation or because of troop movement during the activity. 

For most activities, troop elements were located in a set of discrete 

positions. In these cases, a distribution of exposure around the mean 

exists, rather than an error of the mean. The exposure is computed 

for troops in the hottest positions as well as that for the "average" 

troops. 

The decay curve for a particular shot may be treated as exact 

to the extent that the measured fallout decay is representative of the 

entire fallout field for that shot. Because insufficient information 

exists to evaluate the assumed independence of decay rate with oosition 

and the accuracy of the decay plots of Reference 11, the presumably small 

errors associated with these will be neglected. All decay curves except 

for Shot SHASTA have at least partial reliance on Plumbbob Composite 

decay. Therefore, all other shots have an associated decay error that 

arises from that mean decay. An assessment of the variation in decay 

of the shots comprising Plumbbob Composite, together with the observation 

that the variation is minimally dependent on the duration of Plumbbob 

Composite decay utilization, yields an error factor of 1.3. This applies 

to all shots except SHASTA for the fallout intensity on the dates of 

troop activities. 

Error resulting from impreciseness of troop arrival time in a 

fallout field is minimal. Because the activities were conducted some 

two weeks or more after shots yielding the fallout, even the day-to-day 

decay during extended exercises never exceeded 10 percent. Consequently, 

error from this source can be disregarded. 

The error in duration of an activity can range from zero for 

precisely logged events to a substantial value for inferred activities. 

!Jhen durations are not precisely known, their uncertainties are estimated in accordance with sound military judgment. 

52 
As may be seen from Section 4.2, exercises in the DIABLO 

fallout field on 12-14 August and in the SHASTA field on 31 August 

resulted in nearly all the residual gamma exposure of the troops. The 

error factors for each are displayed below: 

Fallout Field on Dates 

DIABLO Sl-!ASTA 

Source of Error 12-14 Aug 31 Aug 

Fallout plot intensities 1.46 1.46 

Fallout plot interpolation 1.3 1.3 

PIean troop position 1.0 1.9 

Decay rate 1.3 1.0 

Duration of activity 1.25 1.15 

COMBINED ERROR FACTOR 1.78 1.62 

The error factor providing 90 percent confidence limits for 

the geometric mean of the DIABLO exposure is computed as follows: 

s 

error factor = antilog [(log l.46)2 + 2(1og l.3)2 + (log l.25)2] 

= 1.78. 

For the smaller contributions to the total exposure, the error factors 

are not far from the above and need not be displayed. 

In order to sum the estimated exposures from separate activities, 

the geometric (lognormal) error distributions are approximated by 

arithmetic (normal) distributions. For the magnitude of the error 

factors calculated, the arithmetic mean is slightly greater than the 

geometric mean. In addition, symmetric error bands are approximated 

to assist in the error determination of the total exposure. For DIABLO 

and SHASTA this yields approximately 280 + 159 mrem and 130 k 60 mrem, 

respectively. For the smaller contributions to the total dose, 

the correction to the mean is insignificant. 

53 
The arithmetic mean dose (to the nearest 10 mrem) from 

each activity and the totals are summarized in Table 2. For the troops, 

total 

dose = (28Ok150) •t (130+60) + (30215) + (2OklO) + (2OklO) + (lOk5) 

= 490 k (1502 + 602 + 152 + lo2 + lo2 + 52)4 

= 490 k 160 mrem. 

Those troops in the hottest areas of the DIABLO and SHASTA fields would 

have been subject to an estimated additional 30 percent from 

DIABLO and 20 percent from SHASTA, for a total of 600 + 220 mrem. 

5.2 INITIAL RADIATION EXPOSURE 

The sources of error in the determination of the initial radiation exposure in the DOPPLER trenches include: (1) the calculation of 

the radiation field above the trenches, (2) the downward-directed fraction of that field, (3) the assumed angular independence of that downdirected component, (4) the statistical uncertainty of the Monte Carlo 

calculation, (5) the assumed torso depth within the trench, (6) the 

specified torso orientation, and (7) the truncation of the trench at a 

ten-foot length. The magnitude of the uncertainties in these quantities 

is stated or implied in Section 3.2. 

Error factors, expressed in terms of 90% confidence limits, are 

displayed below for y (film badge equivalent), y (free-in-air), and 

n (free-in-air). 

Source of Error v(badge) y(free) n(free) 

Field above trenches 1.5 1.5 1.25 

Downward-directed fraction 1.1 1.1 1.1 

Angular independence 1 upper 1.0 1.0 1.0 

lower ----------undetermined 

Monte Carlo calculation 1.20 1.15 1.17 

Torso orientation (upper ally) 1.1 1.0 1.0 

Truncated trench (upper only) 1.1 1.1 1.1 

COMB1 NED ERROR FACTOR 1.69 1.65 1.46 

(upper only) 

54 
- - 

- - - - - - 

- - - - - - 

- - 

- - - - - - 

- - - 

- - 

- - - 

- - - - - 

TABLE 2. SUMMARY OF CALCULATED RESIDUAL RADIATION DOSE (mrem) FROM 

ACTIVITIES CONDUCTED IN CONNECTION WITH SHOT SMOKY 

ACTIVITY 

a C e f TOTALS 

RESIDUAL DOSE Rehearsals Phase I Witness Phase II, III Equip. Phase I 

(mrem) (5-9 Aug) Preparation SMOKY Exercises Recovery Inspect 

(12-14 Aug) (31 Aug) (31 Aug) (1 Sep) (1 Sep) 

SHOT 

BOLTZMANN 20 20 

FRANKLIN 

WILSON 

DIABLO 10 280 (30)* 290 

!i - s! - -

-

KEPLER 20 30 50 

PASCAL "A" 

SHASTA 130 (60)* (40)* 130 

FRANKLIN PRIME 

SMOKY (50)* 

GALILEO 

TOTALS TF Troops 30 300 30 130 (oO)* (120)* 490 

*(doses in parentheses are ascribed to an unidentifiable subgroup). 
The error factors on the lower side are at least as great as 

the above values of combined error factor. Therefore the lower error 

bands stated below are underestimated. 

In order to combine the estimated initial radiation dose 

(455 mrem free-in-air, 133 mrem film badge equivalent) with other 

exposures accrued by Task Force WARRIOR, the geometric error distributions are converted to arithmetic distributions. The resultant 

adjusted mean values and associated symmetric 90 percent confidence 

limits for the initial radiation dose are 480 + 220 mrem for total 

free-in-air dose and 140 + 75 mrem for the film badge equivalent. 

5.3 TOTAL EXPOSURE 

The total free-in-air dose estimate for Task Force WARRIOR 

is 970 + 270 mrem, determined from summing the above initial dose of 

480 2 220 mrem and the residual contribution of 490 _+ 160 mrem calculated in Section 5.1. The film badge equivalent, determined in part 

by the conversion factor of .70 for residual gamma radiation (discussed 

in Section 6 and Appendix III), is 480 -t 135 mrem. 

56 
Section 6 

FILCl BADGE DOSIMETRY 

6.1 EXPOSURE CORRECTIONS TO FILH BADGE EQUIVALENCE 

Traditionally, film badge readings have been assumed to 

nearly approximate whole body radiation exposures. More specifically, 

a film badge worn on the front of the upper body had been assumed to 

indicate a 5 cm depth dose to the wearer; that is, the body shielding 

of radiation from the rear is offset by the lack of body shielding of 

radiation from in front of the wearer. Because of the potential importance of all traditional assumptions, the above approximations were 

analyzed specifically for the SMOKY study. The results of the analysis 

are provided in Appendix III. 

The residual radiation intensities calculated in Sections 4.2 

and 5.1 are given in terms of rem, a measure of free-field tissue dose. 

The exposures so obtained, therefore, cannot be compared directly 

to film badge readings where body shielding affects the exposure recorded 

by the wearer's film badge. A correction factor of 0.70, obtained from 

Appendix III, is applied to the calculated doses to permit direct 

comparison with film badge readings. 

For the initial radiation intensities calculated in Section 3.2, 

there is no generally applicable correction factor. An independent 

calculation of film badge equivalent was required. The ratio of dose 

to its film badge equivalent is dependent on the neutron/gamma 

ratio, anisotropy of the radiation field, and geometry of the body-intrench configuration. As mentioned in Section 3.2, the film badge is 

very insensitive to neutrons. 

6.2 FILM BADGE DATA 

The data set for Task Force I*IARRIORwas obtained by direct 

examination of the Lexington-Blue Grass Army Depot film badge records. 

Not only was a complete and accurate set obtained thereby, but a critical 

57 
evaluation of the data was also afforded. Some difficulties were noted 

in categorization of the film badge records. For 22 badges which were 

lost, an "integrated reading" was assigned as a dose. It appears that 

these doses were assigned on some basis other than the task force 

average for the badge period, for they almost invariably exceed it 

substantially. Consequently, these doses were disregarded in the 

statistical analysis. Another incongruity among the film badges was 

the lack of a uniform badge period. Only equivalent badge periods 

warranted direct comparison of the readings. Some task force subgroups 

had differing periods generally, and several individuals had anomalous 

badge periods, sometimes including overlaps, for such reasons as late 

arrival at Camp Desert Rock or early departure therefrom, a lost 

previous badge, a suspected significant exposure, and absence during 

regular film badge exchanges. 

Most of the 603 individuals in Task Force WARRIOR were issued 

two film badges. The predominant periods were from 25 or 26 July to 

27 August 1957 and from 27 August to 2 September 1957. Subgroups with 

differing intervals were task force headquarters personnel (24 July to 

14 August and 14 August to 2 September) and the Canadian platoon (25 July 

to 20 August and 20 August to 2 September). In all cases, the second 

period included SMOKY. More than 90 percent of the periods shown on 

the film badge records correspond to one of the above periods. 

As discussed in Section 4.2, the dose estimates for Task 

Force WARRIOR were made assuming no distinction among the subelements 

(such as platoons). Other than as noted above, the film badge records 

do not contain subelement affiliation, and at this time there appears 

to be no means to identify such affiliation. The film badge data 

therefore are presented as a single group within a particular badge 

period. It is apparent from the distribution of readings, however, 

that distinct components may be present. 

58 
Shown in Figure 13 is a two-dimensional plot for those cases 

having records for at least one of the predominant periods (ending or 

starting on 27 August). The first row and column of the plot correspond to zero readings and disqualified film badges. The zeroes include 

those readings which are not above the film badge threshold (about 25 

mrem). Disqualified records include those badges described as blank, 

lost, not turned in, light struck, damaged, or opened. Badges not 

closely corresponding to the other period fall into this group as 

well. Two clusters are evident in this plot. Their statistical 

characteristics are as follows: 

No. of Mean* and Standard Deviation of Readings 

Cluster Cases 25 July - 27 Aug. 27 Aug.- 2 Sept. 

1 387 390 f 150 185 + 60 

2 20 405 + 130 1140 f 150 

* In determining the mean, any case with a disqualified badge or a subthreshold reading was disregarded. 

Figure 14 depicts the distribution of readings for each period 

separately. The figure clearly shows that, for the majority of cases, 

the first period readings were usually about double those for the 

second period covering the SMOKY maneuvers. There are exceptions to 

this, the most prominent of which is the cluster of 20 cases referred 

to above for which the second period reading was about three times 

the first period reading. 

6.3 INTERPRETATION OF FILM BADGE DATA 

Several conclusions can be drawn from the film badge data 

independently of a quantitative comparison with exposure estimates. 

The presence or absence of accrued doses in various film badge periods 

can help supplement the knowledge of what activities transpired in 

Yucca Flat. Furthermore, the distribution of readings permits inferrences to be drawn concerning the uniformity of troop movements. 

59 
60 
-- 

I

120 

1 . 

105 I 25 July - 27 August 

4 Total Number = 523 

15 one reading 

of 1040 

I I a 1 I I . I I 

0, 200 400 600 800 11 3 

I

p35q. 210 

180 ’ I 27 August - 2 September

Total Number = 502 

’ I . 

60 

30 

1 22 readings over 800 

1 I I 1 I a I I . 0 

0, 200 430 600 800 1000 

Film Badge Reading (mrem)

Dis:Calified 

Figure 14. Distribution of Film Badge 

Readings for Each Period 

61 
The absence of gamma doses for an appreciable minority of Task 

Force WARRIOR troops is inconsistent with the record of events on the 

day of Shot SMOKY. For the main body of troops (who exchanged badges 

27 August), only 3 had zero or subthreshold film badge readings for the 

first period, whereas 89 did for the second period. Apparently these 

89 neither observed SMOKY from the location specified in Plan B 

(Reference 4) nor participated in the subsequent airlift exercise, for 

in either event gamma radiation would have been measured. The photographic evidence demonstrates that the remaining task force personnel 

may have witnessed SMOKY from News Nob, where no measurable radiation 

was present. In Figure 15, the rightmost of the nine troops shown 

"observing" Shot SMOKY from News Nob was identified by the Army as PFC 

McGinnis of Task Force WARRIOR. Unfortunately, his film badge is 

reported to have been lost, so verification from his film badge reading 

is impossible. The troops' evident lack of field gear suggests that 

they did not plan to later join the SMOKY exercise. 

A comparison of film badge readings from different overlapping 

periods is useful in temporal resolution of the doses that were accrued. 

Three groups that permit such resolution are the Canadian platoon, the 

task force headquarters personnel, and the main body of troops. All 

received their first film badges in late July (the exact date is not 

important), and all turned in badges on 2 September. Assuming that the 

personnel in each group performed the same activities (which appears to 

be true owing to similar total dose levels), the various badge exchange 

dates permit sub-period information to be extracted. In the chart below, 

the statistical information for each group is presented, disregarding 

outliers which will be discussed later. 

62 

Standard Standard 

Group Period Number of Cases Mean (mrem) Deviation Error 

Main before 27 Aug 470 392 153 7 

Canadian before 20 Aug 38 271 106 17 

Ho before 14 Aug 28 250 150 29 

Main after 27 Aug 387 186 59 3 

Canadian after 20 Aug 38 338 53 9 

Hg after 14 Aug 15 365 88 22 

Any two groups may be compared by differencing both their badge 

periods and readings. Two values of net dose result for a sub-period so 

determined (unless the total doses are identical). For example, a comparison of the main and Canadian groups indicates that for the period 

20 to 27 August, the dose differences are 121 ? 18 (standard error, or 

standard deviation of the mean) mrem and 152 5 9 mrem. Similar analysis 

for all pairs of groups provides the following information: 

Mean Dose and Standard Error 

Period [mrem) for Each Possibility) Approx. Net Mean Dose (mrem) 

20-27 Aug 121 ? 18, 152 2 9 140 ? 20 

14-20 Aug 21 + 34, 27 F 24 25 * 30 

14-27 Aug 142 + 30, 179 + 22 165 ? 35 

Between 14 and 20 August, as seen above, it is not certain that 

Task Force WARRIOR received any dose. Any possible dose would have been 

small. Documentation of Task Force WARRIOR activities does not indicate 

any training in areas contaminated with residual gamma radiation. For 

the week of 20 to 27 August, the inferred 140 + 20 mrem film badge dose 

is clear indication of a task force activity in the forward area. On 

the 23rd, it is known that Task Force WARRIOR observed Shot DOPPLER from 

trenches. No other dose-yielding activity for the task force is reported 

for that week. Two visiting general officers with film badge periods of 

22 to 23 August and 19 to 23 August had readings of 119 and 156 mrem, 

respectively. Observation of DOPPLER from the trenches would have been 

64 
their most logical activity in the forward area. Seven soldiers had a 

film badge period of 14 to 30 August. Given that no dose was accrued 

between 27 and 30 August, their mean dose of 164 ? 34 compares well 

with the value for 14 to 27 August obtained above from larger sample 

spaces. 

By yielding film badge values that can be associated with 

smaller time intervals and thus more likely with single exercises, a 

more detailed comparison will be possible between exposure estimates 

and film badge readings. 

6.3.1 Outliers 

The principal departure from the main film badge distributions 

of Task Force WARRIOR is the group of 20 troops who received between 

800 and 1400 mrem during the period 27 August to 2 September. Not 

only are their doses far above all readings in the main distribution 

but reasonably similar as well. The spectrum of the radiation is 

similar for all 20 film badges, as judged by similar attenuation ratios 

between pairs of filtered elements of the film badge described in 

Appendix III. That all beta radiation doses in this group are similar 

(under 100 mrem) is evidence of the spectral similarity. 

From the above, it may be presumed that the group of 20 was 

indeed together. If the high dose was, as presumed, accumulated on 

the day of SMOKY, it follows that the group would have been closer to 

SMOKY GZ than the task force as a whole. Nowhere else on 31 August 

could the 800 to 1400 mrem dose level have been achieved unless the 

group was subjected to the radiation field of SMOKY itself. It 

could be postulated from the film badge evidence, together with the 

structure of the group (one LT, one M/Sgt, one SFC, one Sgt, one Cpl, 

and 15 other EM) that a platoon section, or like patrol or task group, 

could have proceeded due east from the objective area toward Smoky Hill 

and the Phase I positions instead of assaulting Quartzite Ridge to the 

northeast. Whether such an excursion was by oversight or design is 

65 
imnaterial. In either case, it is undocumented, The excursion would 

explain, however, why the assault was halted due to rad-safe considerations, presumably at the 500 mr/hr level. An examination of the SMOKY 

residual contamination contours would support this hypothesis--the 

group would have halted short of Smoky Hill near the Phase I defensive 

positions, having proceeded less than two miles in about 45 minutes. 

Although halted, they could have remained in the vicinity of the 500 

mr/hr line until exercise termination at 0945, inspecting the post-shot 

damage to the defensive positions they had prepared more than two weeks 

previously. If they had adhered to the 500 mr/hr limit, had not 

encountered any hot spots, and had departed promptly at exercise termination, their total -dose from this excursion would have been about 

300 mrem. They may have encountered hot spots, however. It is also 

possible that they ventured toward the close-in positions where intensities were greater, or stayed long enough to view all the positions. 

Given the uncertainties of this excursion, doses on the order of 

1000 mrem cannot be ruled out. 

There are also individual outliers that deserve mention. One 

dose of 2500 mrem, accrued between 27 August and 2 September, was accompanied by a beta reading of 2600 mrem. Another gamma dose of 2000 mrem 

during the same period was accompanied by 920 mrem-beta. Very few film 

badges for Task Force WARRIOR had these large beta/gamma ratios. As 

distinguished from the group of 20, the high beta readings would indicate that the film badges were on the ground for considerable periods, 

possibly having been lost during the SMOKY exercise and found during 

the subsequent equipment recovery on 1 September. 

The highest single reading of 2740 mrem was obtained between 

27 and 30 August by a master sergeant, yet no known troop activity 

transpired in that interval. The badge record was initially labeled 

"lost," then altered to record the dose. It is likely that this badge 

had indeed been left for a substantial time in a gamma field of some 

intensity. 

66 
Of the task force headquarters group, the task force commander 

and a lieutenant accrued 920 and 695 mrem gamma, respectively, between 

14 August and 2 September. It is reasonable to assume that these individuals would have spent considerable extra time in the forward area, 

accounting for considerably higher doses. A few other troops had 

readings in this range on single film badges from early August to 

2 September. Since this period probably encompassed almost all radiological activities of the task force, these troops' doses may be 

regarded as high-average. 

Some qualitative account may be given to the spread of the 

film badge readings. In addition to the approximate 10 percent inaccuracy of individual film badges (see Appendix III), the data spread 

is influenced by the distribution of troops throughout the exercise 

area (as discussed in Sections 2.6 and 4.2), possible incomplete 

attendance by troops at all rehearsals, extra activities requiring few 

personnel (such as equipment recovery and Phase I inspection), differing 

arrival times (as documented for the SMOKY exercise), and local variations in the residual radiation intensity. 

67 
- . 

68 
Section 7 

CONCLUSIONS 

There were nine shots during Operation Plumbbob which could 

have contributed to the residual radiation exposure of Task Force WARRIOR 

and related units which participated in the Infantry Troop Test conducted in conjunction with Shot SMOKY. Additionally, Shot DOPPLER 

contributed an initial radiation component to the total. Of the nine 

shots with possible contribution to exposure from residual radiation, 

four were of little or no significance. The other five contributed in 

varying degrees to the total exposure, as shown in Table 2. It should 

be noted that Shot SMOKY contributed little if any dose to the 

troop units discussed. It is apparent from the GALILEO report (Reference 23), however, that the SMOKY fallout was a major contributor to 

the radiation exposure of Task Force BIG BANG in conjunction with the 

HumRRO troop test. The discussion of this activity and the exposure 

associated therewith is contained in the GALILEO report (to be published). 

A comparison of the film badge readings with the calculated 

dose for Task Force WARRIOR is made by applying the correction 

factor of 0.70, obtained in Section 6.1, to the doses calculated 

in Sections 4.2 and 5.1. This adjustment yields a total film badge 

equivalent value of 340 mrem from residual radiation. To this value, 

the calculated and adjusted initial contribution from DOPPLER (about 

140 mrem) is added, yielding a total of 480 mrem. This is comparable 

to the combined mean reading of 575 mrem obtained from the film badges. 

Except for the group of 20 (discussed in Section 6.3), the 

calculated (and adjusted) doses correlate reasonably well with the 

two primary film badge issue periods. For the first period, up to 

27 August, the calculated dose of 330 mrem is adjusted to 230 mrem, 

to which the DOPPLER contribution is again added for a total of 370 mrem. 

This compares to the first period mean film badge reading of 390 mrem. 

For the second period, the calculated dose, after adjustment to film 

badge equivalence, is 110 mrem, which compares to the mean film badge 

reading of 185 mrem. 

69 
Table 3 summarizes free-in-air doses and inferred film 

badge exposure-equivalent values, and lists film badge readings for 

comparison. The data result from all efforts to reconcile the available information on the history and magnitude of test personnel radiation exposure. It is evident the data indicate that film badge records 

compare well with equivalent values inferred from radiation field 

measurements and troop movement records. The mean total film badge 

reading is within the 90 percent confidence limits of the adjusted total 

dose estimate. 

In the same manner that film badge readings were compared to 

the adjusted dose estimates, a reasonable upper limit of troop 

exposure is deduced and compared to the highest film badge readings. 

For this purpose, mean dose values ascribed to various events 

are cons dered correct, but the distribution of position and stay time 

among the troops causes calculable exposure variation. The former, as 

discussed in Section 5.1, permits the estimated residual dose to be 

as much as 600 mrem. Stay times might have been as much as 25 percent 

higher than the mean for some troops because of extended arrival and 

departure intervals, especially when helicopters were used. Those few 

troops participating in the equipment recovery and post-shot inspection 

of Phase I defensive positions would have accrued 180 mrem more than the 

task force as a whole (see Table 2). Thus, some individuals could have 

been exposed to 930 mrem (650 mrem film badge equivalent) of residual 

radiation. 

The initial radiation dose from Shot DOPPLER may have been considerably greater than the mean in some cases. The following might represent an extreme: a soldier misestimates his depth in the trench so 

that his head, which is bent over a nearly erect torso, is only 1 foot 

below surface level. His film badge, worn on his collar (as some 

personnel did) and essentially unshielded, is at about the same 1 foot 

depth. This individual would have accrued about 400 mrem on his film 

badge. The free-in-air dose at mid-torso depth would have been 

70 
TABLE 3 

COMPARISON OF DOSES AND FILM BADGE 

EQUIVALENCE WITH FILM BADGE DATA 

TASK FORCE WARRIOR TROOPS 

Period 

25 July - 14 August 

Free-In-Air 

Exposure {a} 

(mrem) _ 

33Ok 150 

Film Badge Film Badge Inferred Mean 

Exposure Equivalence {a} Readings {b} Film Badge Doses {al 

(mrem) (mrem) (mrem) 

230 +105 I 250+ 50 

14 August - 20 August 0 0 390+ 240 25+ 50 

20 August - 27 August 480t220 {dl I.4.40! + 75 14Ok 35 

27 August - 2 September 160 k 60 110 5 40 185 + 95 

TOTALS 9"/?'+ 270 Id) 480t 135 575 +250 {cl 

a With 90 percent confidence limits. 

b With 90 percent data range. 

c Includes all troops with full participation in TF WARRIOR. 

d The lower error bands are underestimated. 

The unit of exposure is independent of specific biological effects. 
about 500 mrem (including neutrons), which, like this individual's 

mid-torso position, would have been near the mean. If this individual 

were in the front trench rather than the middle trench, his dose 

would have been 13 percent greater for gamma and 26 percent greater for 

neutrons. 

Combining residual and initial doses, the upper limit of 

dose is estimated to have been 930 + 600 = 1530 mrem, with a film 

badge equivalent of 650 + 450 = 1100 mrem. If the group of 20 and 

the three outliers exceeding 2000 mrem (discussed in Section 6.3) are 

excluded due to evident incompatibility with the troop movements as 

known, the film badge equivalent of the upper exposure limit compares 

favorably with the highest combined film badge readings for any individual (1235 mrem; 1090 mrem is next highest). 

72 
Section 8 

REFERENCES 

1. Reynolds Electrical Engineering Co., Inc.,Nevada Test Site, 

Mercury, Nevada, "Plumbbob On-Site Rad-Safety Report," 

undated (OTO-57-2). 

2. Nevada Test Site,"Report of the Test Manager, AEC/NTO, 

Operation PLUMBBOB," December 1957. (S) 

3. Headquarters, Sixth US Army, Presidio of San Francisco, 

California, "Exercise Desert Rock VII and VIII, Final 

Report of Operations," January 1958 (AG-S-9531). 

4. Headquarters, Sixth US Army, Presidio of San Francisco, 

California, "Report of Test, Infantry Troop Test, Exercises 

Desert Rock VII and VIII," 11 Dee 1957 (AMCDR-S-3). 

5. WT-1444, "Operational Sumnary," Operation Plumbbob, February 23, 

1960, Hq., Field Command, DASA. 

6. Camp Desert Rock, Nevada, "Operation Order 17, SMOKY, Desert 

Rock VII and VIII," undated. 

7. S. Glasstone and P.J. Dolan, "The Effects of Nuclear Weapons," 

1977, United States Department of Defense and United States 

Dept. of Energy, Washington, D.C. 

8. D.L. Rigotti et al, WT-1412, "Neutron Flux from Selected 

Nuclear Devices," April, 1960, Edgewood Arsenal, MD. (SRD). 

9. R.J. Smith et al, NDL-TR-53, "Initial Gamma Data from Nuclear 

Weapon Tests 1948-1962," July 1965, Edgewood Arsenal, MD. (SRD). 

10. DASA 1251, "Local Fallout from Nuclear Test Detonations," Vol. II, 

Part 2, US Army Nuclear Defense Laboratory (NDL), Aug. 1963. (SRD). 

11. K.H. Larsen, et al., WT-1488, "Distribution Characteristics 

and Biotic Availability of Fallout Operation PLUMBBOB," 

Projects 37.1, 37.2, 37.2A, 37.3, and 37.6. 

73 
12. DuPont pamphlet, "Dosimeter Films," E.I. DuPont De Nemours and 

Co. (Inc.), Photo Product Department, Wilmington, Delaware, 

circa 1950's. 

13. Ehrlich, M., "A Photographic Personnel Dosimeter for X-Radiation 

in the Range from 30 keV to Beyond 1 MeV," Radiology, Vol. 68, 

No. 4, pp. 549-554, April 1957. 

14. William J. Brady, REECO, Las Vegas, Nevada, private communication, 27 April 1978. 

15. Lexington Blue Grass Army Depot (SDSRR-LQCP) letter to JAYCOR, 

Subject: Film Badge Information, 16 June 1978. 

16. Kaul, 0. and Jarka, R., "Radiation Dose Deposition in the Active 

Marrow of Reference Man," DNA 4442F, October 1977. 

17. Spencer, L.V., "Structure Shielding Against Fallout Radiation 

from Nuclear Weapons," National Bureau of Standards Monograph 42, 

1962. 

18. French, R.L., et al, "Gamma Ray Energy and Angular Distributions 

Near the Air-Ground Interface From Plane Fallout and Point Co 60 

Sources,' AFRRI Report RRAM42, 1 June 1964. 

19. Huddleston, C.M., et al, "Ground Roughness Effects on the Energy 

and Angular Distribution of Gamma Radiation From Fallout," AEC 

Report CEX-62.81, July 1964. 

20. Huszar, L., et al, "Version 4 of ATR (Air Transport of Radiation)," 

DNA 3995, January 1976. 

21. NCRP Report No. 38, "Protection Against Neutron Radiation," 

4 January 1971. 

22. Straker, E.A., et al, "The Morse Code with Combinatorial 

Geometry," DNA 2860T, May 1972. 

23. Science Applications, Inc., Draft Report for Director, DNA, 

"Analysis of Radiation Exposure for Task Force BIG BANG, Shot 

GALILEO, Exercise Desert Rock VII-VIII, Operation Plumbbob," 

November 1978. 

74 
24. WT 1445, Operation Plumbbob, Technical Summary of Military 

Effects, Programs 1 through 9, August 15, 1962. (SRD) 

25. Cook, C. S., et al, WT 1411, Operation Plumbbob, NeutronInduced Activities in Soil Elements, Project 2.2, July 31, 

1959. ( SRD) 

26. Huszar, L., et al, "Energy Dependent Air/Ground Correction 

Factors for the ATR (Air Transport of Radiation) Code," BRL 

Report No. 345, August 1977. 

27. Gritzner, M. L., et al, "Radiation Environments from Tactica 1 

Nuclear Weapons," DNA 4267F, July 1976. 

28. Hurst, G. S., et al, "Radiation Dosimetry for Human Exposure s ) ” 

CEX 39.5, March 1958, (SRD). 

29. Langham, W. H., et al., "Radiobiological Factors in Manned 

Space Flight," NAS 1487, 1967. 

30. Straker, E. A., "Time-Dependent Neutron and Secondary GammaRay Transport in an Air-Over-Ground Geometry," ORNL-4289, 

Sept. 1968. 

31. "The Effects on Population of Exposure to Low Levels of 

Ionizing Radiation," NAS, Nov. 1972. 

32. Katz and Sharma, "RBE - Dose Relations for Neutrons and Pions," 

Phys. Med. Biol., 1975, Vol. 20, No. 3, 410-419. 

75 

- A - -~ - -_ --_ 
_-

- I._-. --- L -

76 
APPENDIX I 

FALLOUT PLOTS 

Because the radiation dose accrued by individuals at the Nevada 

Test Site in 1957 was caused, to a significant extent, by the exposure 

to fallout from several shots, it is imperative that all Plumbbob shots 

be examined and, where appropriate, the fallout plotted. Table I-l 

lists the shots that were examined and identifies those for which 

fallout plots are produced in the figures following. For those not 

plotted, the reason is primarily that the height of burst was sufficient for that yield to reduce local fallout, beyond the immediate 

area around ground zero, to insignificant levels. This is verified 

through inspection of post-shot rad-safe surveys by Reynolds Electrical 

Engineering Company (REECO) and the Civil Effects Test Group (CETG), 

Program 37 (References 1 and 11). 

The fallout plots shown in Figures I-l through I-9 were 

derived from the information contained in the above references. Plots 

of actual radiation levels, measured at specific times after each 

shot, were normalized to H+12 hours by using the decay schemes described 

in Appendix II. A single composite fallout plot was obtained from the 

survey data through averaging the normalized values. The REECO dose 

rate plots were not used in their entirety; only actual data points 

were considered (where the REECO iso-intensity contours intersect 

roads). Because the roads depicted in the REECO plots were sufficiently straight, sets of collinear data values were obtained which 

could be processed mathematically. 

Because dose rates tended to vary exponentially with distance, 

the data were fit to an exponential form. The simplest, after taking 

logarithms, is 

log b = ax + b 

77 
TABLE I-l 

OPERATION PLUMBBOB FALLOUT DETERMINATION 

28 MAY TO 2 SEPTEMBER 1957 

SHOT YIELD DATE & TIME BURST HEIGHT AREA COORD FALLOUT 

BOLTZMANN 12KT 28 May, 0455 500' Tower 7 867056 Fig. I-1 

FRANKLIN 140T 2 Jun, 0455 300' Tower 3 870004 Fig. I-2 

LASSEN .5T 5 Jun, 0455 500' Balloon 9b 852100 Insig. 

WILSON 1OKT 18 Jun, 0455 500' Balloon 9b 852100 Fig. I-3 

PRISCILLA 37KT 24 Jun, 0630 700' Balloon FF 956729 Offsite East 

HOOD 74KT 5 Jul, 0440 1500' Balloon 9b 852100 Insig. 

DIABLO 17KT 15 Jul , 0430 500' Tower 2b 792118 Fig. I-4 

KEPLER 1OKT 24 Jul, 0450 500' Tower 4 797057 Fig. I-5 

OWENS 9.7KT 25 Jul, 0630 500' Balloon 9b 852100 Insig. 

PASCAL "A" S(N) 26 Jul , 0100 Underground 3j 858009 Fig. I-6 

STOKES 19KT 7 Aug, 0525 1500' Balloon 7b 867047 Insig. 

SHASTA 17KT 18 Aug, 0500 500' Tower 2a 794093 Fig. I-7 

DOPPLER 1lKT 23 Aug, 0530 1500' Balloon 7b 867047 Insig. 

FRANKLIN 

PRIME 4.7KT 30 Aug, 0540 750' Balloon 7b 867047 Fig. I-8 

SMOKY 44KT 31 Aug, 0530 700' Tower 8(2c) 828159 Fig. I-9 

S(N) - Safety shot with some nuclear yield 

78 
A least squares linear regression was performed on log D. The locations . 

of D=lO, 100, and 1000 mr/hr were obtained according to the fit. Usually, 

the data, when normalized to H+lZ, spanned these values. If not, no 

extrapolation was performed. 

The log-linear fit is clearly inappropriate across GZ or the 

hot line. A higher order fit, akin to a Gaussian, was tried in order 

to permit a functional maximum: 

log D = ax2 tbxtc 

While this form was useful in obtaining gamma intensity on hot lines, it 

underestimated GZ values. When used on data not crossing GZ, there 

was a tendency toward unrestrained exponential growth (i.e., positive a), 

just_ as for the log-linear fit. So long as the data lines did 

not cross GZ or the hot line, the difference in 10, 100, and 1000 mr/hr 

locations from the first order to second order fit was well within the 

standard deviation of the data. For these reasons, the log-linear fit 

was used to construct composite plots. 

The consistency of the data was assessed from log D(x). The 

standard deviation, o, of log D from the best linear fit was computed 

along all lines used. A markedly similar scatter in the data was observed 

not only from line to line, but also from shot to shot. For all lines 

used on all plots, the error factor, defined as 101*650/dX , where n 

is the number of data points along a line, averages 1.46. Its own standard deviation is 0.05. The consistency of the error factor supports 

the disregarding of isolated data far outside reasonable confidence limits. 

Thus, all the composite plots may be regarded as depicting exposure along the roads within a factor of 1.46, with 90 percent reliability. Where the contours have been interpolated between roads, the error 

factor would be slightly greater. The on-site composite plots were 

reasonably consistent with the off-site surveys from Program 37 (Reference 11). For most shots, interpolation was necessary in the gap between 

the composite contours obtained from on-site surveys and off-site surveys. 

In those cases, azimuthal consistency as well as magnitude determined the 

79 
overall correlation. Where the contours have been interpolated (dashed 

lines), the error factor grows considerably, particularly where contours 

are closely spaced. 

In general, available data was used or interpolated for all areas 

of interest. One obvious exception is evident for SMOKY, where the upwind 

radiation intensity is crucial to determine the dose received by Task 

Force WARRIOR and supporting elements operating in the upwind area. The 

steep terrain obviously prevented post-shot ground or aerial rad-safe 

surveys immediately upwind. The upwind contours were therefore estimated 

as being virtually circular, under the conservative assumption that upwind 

fallout would have carried no farther from ground zero than crosswind fallout, particularly in the face of rising terrain. In this case, as well as 

others, both estimated and interpolated contours are dotted. 

It should be noted that the fallout plots shown in the figures differ from earlier estimates of fallout, such as that provided by the DASA 

1251 report (Reference 10). Because the plots are all derived from the 

same data (References 1 and ll), some explanation for the difference is 

in order. First, presumed actual survey points along roads were used as 

data points rather than the entire sketched contours. Second, DASA 1251 

ascribed more reliability to the contours than could have possibly existed. 

For instance, the northwest quadrant of SMOKY fallout should be considered 

highly suspect simply on the basis that the steep terrain would have precluded surveys in that area. Third, the influence of previous shots on 

subsequent surveys was apparently not considered in DASA 1251. This is 

particularly evident for SMOKY, where the REECO surveys were biased by the 

northerly SHASTA fallout of two weeks previous and DIABLO fallout of seven 

weeks previous. Thus, any composite SMOKY fallout plot, using REECO data, 

would reflect higher intensities on the western side than actually resulted 

from shot SMOKY itself. Finally, the DASA 1251 fallout contours were nor-

-1.2 malized (to H+l) using a decay rate of t . The plots contained herein 

are normalized to H+12 through the use of actual shot decay rates where 

available from Program 37. Where the actual data are not available, the 

composite Plumbbob decay is used. In either case, significant variations 

from the traditional t-ls2 "rule" are evident. This is discussed in Appendix 11 where actual decay rates and schemes used to derive the composite 

plots are described in greater detail. 

80 
1 

.~ I ..A -_ I , ^ 

.” I 1. \v \\ : I . 

BOLTZMANN Fallout 

: _,--.1 Derived from References 1, 11 
FRANKLIN Fallout _ 

H + 12 (mr/hr) 

I 
y 0 2000 ; 

WILSON Fallout 1 4 7'02

Meters 

- _.- - A 
- - 

I I 

-_. Figure I-4. DIABLO Fallout , 6. H ;:~,m;-/hr) \ 

- -. 
_ _-

- --a 

/ ‘.’ ’ _, 1 -; . . _ 

, i 1, 

[

c. \ \I 1 

i H + 12 (mr/hr) 

I 18 August 

-,j 

1 

Derived from References 1, 11 1 87 

T_._ C___- Figure I-7. SHASTA Fallout f _ ! 
PRIME Fallout O- 2000~~-- Meters 

- a_-- -
.:_ _-___(-L 

i ; H t 12 (mr/hr)

I 31 August :“ ._J Derived from References , ?\, i _;_ ,_ ~___“~.T--‘__j, -. I _-. 

- A----
90 

L -_ -_--

-
APPENDIX II 

FALLOUT DECAY 

The decay of fallout contamination was examined in detail for 

two specific reasons. First, the rate was used to normalize all survey data to H+lZ. From these reduced data, the fallout plots shown 

in Appendix I were constructed. Second, precise decay rates were 

needed to facilitate evaluation of the actual intensity of each fallout field at various times after the shot when troop units were 

operating therein. 

Several decay curves were examined, particularly the actual 

decay rates for specific shots as measured by Program 37 (Reference 

11) whenever they were available. For the other shots where no decay 

data was available, the Plumbbob composite decay, as compiled by 

Program 37, was examined. It was noted that these decay rates vary 

considerably from the traditional t-1.2 "rule". They also vary from 

the decay rate used in the DELFIC code (DOD Standard fallout model), 

which determines a composite decay from the decay of each fission 

product. While DELFIC agrees quite well with the t-1*2 "rule", it 

does not consider the case of tower shots where substantial amounts 

of extraneous material, such as iron, may be in the fireball. 

The actual decay rates were used for Shots BOLTZMANN, DIABLO, 

SHASTA, and SMOKY. These are shown in Tables 11-l through 11-J. 

For all other shots, the overall Plumbbob composite decay was used, 

as shown in Table 11-5. 

Although the differences in decay rates are not significant 

for some time intervals, it should be noted that the actual decay 

-1.2 rates are generally more consistent with each other than with t . 

9.1 
TABLE II-1 

BOLTZMANN FALLOUT DECAY 

H+ (hours) Decay Rate, x* 

(2 Plumbbob Composite 

2-3 -0.65 

3-5 -0.89 

5-8 -1.00 

8-13 -1.33 

13-900 Plumbbob Composite 

900-1400 -1.17 

1400-4000 -1.20 

* 

as used in the expression, tX 

Source: Reference 11 

Conversion of REECO Survey DaWto H+12 

Survey H+ Factor 

Initial (0551) 0.927 .030 

H+8 (1319) 8.4 .622 

D+l (0648) 25.9 1.90 

D+3 (0550) 72.9 4.46 

D+7 (1352) 177 11.8 

* Reference 1 

92 
TABLE II-2 

DIABLO FALLOUT DECAY 

H+ (hours) Decay Rate, x* 

1-2 Plumbbob Composite 

2-5 -1.30 

5-6 -1.71 

6-15 -1.13 

15-25 -0.50 

25-30 -2.38 

30-80 Plumbbob Composite 

80-180 -1.06 

180-300 -1.84 

300-400 -1.64 

400-600 -1.33 

600-2300 -1.21 

* 

as used in the expression, tX 

Source: Reference 11 

Conversion of REECO Survey Data*to H+12 

Survey H+ Factor -

Initial (0551) 1.35 .043 

H+7 (1118) 6.8 .526 

D+l (0645) 26.25 1.87 

D+2 (0652) 50.4 3.74 

D+3 (0642) 74.2 5.45 

D+4 (0755) 99.4 7,33 

* Reference 1 

93 

- _ - PA - -
TABLE II-3 

SHASTA FALLOUT DECAY 

H+ (hours) Decay Rate, x* 

<3 Plumbbob Composite 

3-5 -1.21 

5-8 -0.92 

8-10 -0.65 

10-70 -0.76 

70-180 -1.21 

180-400 -1.67 

400-1500 -1.28 

1500-3000 -1.19 

* 

as used in the expression, tX 

Source: Reference 11 

Conversion of REECO Survey Dat$to H+12 

Survey H+ Factor -

Initial (0740) 2.7 0.21 

H+6 (1124) 6.4 0.61 

D+l (0729) 26.5 1.83 

D+2 (0650) 49.8 2.95 

D+3 (0625) 73.4 4.05 

* Reference 1 

94 
TABLE II-4 

SMOKY FALLOUT DECAY 

H+ (hours) Decay Rate, x* 

3-6 Plumbbob Composite 

6-8 -1.34 

8-19 -0.74 

19-42 -0.83 

42-85 -0.95 

85-650 Plumbbob Composite** 

650-800 -2.39 

800-900 -1.23 

900-1400 -1.00 

1400-3000 -1.17 

* 

as used in the expression, tX 

**The reference does not portray Plumbbob Composite decay in 

this interval. 

Source: Reference 11 

Conversion of REECO Survey Data*to H+12 

Survey H+ Factor -

H+8 (1309) 7.65 .698 

D+l (0628) 24.97 1.76 

D+3 (1415) 80.75 5.02 

D+5 (1318) 127.8 8.95 

* Reference 1 

95 
TABLE II-5 

PLUMBBOB COMPOSITE FALLOUT DECAY 

H+ (hours) Decay Rate, x* 

<2 -2.18 

2-3 -0.70 

3-6 -1.30 

6-14 -1.03 

14-50 -0.78 

50-1oil -0.90 

loo-180 -1.20 

180-400 -1.58 

400-60C -1.29 

600-1600 -1.34 

1600-3000 -1.45 

3000-4000 -1.68 

4000-5000 -1.76 

* 

as used in the expression tX 

Source: Reference 11 

96 
Figure II-1 is a plot of each specific decay for the shots named, 

together with the Plumbbob composite, compared with the traditional 

decay, all normalized to H+12 hours. 

Thus, to find the dose rate at a time H+t, given the dose rate 

at time H+to, the following expression is used: 

X 

4 = 

60 

where x is the slope of the decay curve, obtained from Tables II-1 

through 11-5, for successive time intervals. In this manner, all 

radiological survey data were normalized to H+12 hours to aid in deriving the fallout plots shown in Appendix I. The iso-intensity 

contours so reconstructed were then used for all subsequent analyses 

of personnel exposures. The analyses required that the actual fallout 

intensities be determined at various times after each shot for specific 

troop locations. Table II-6 shows the factors used in the analyses. 

These factors were derived from the above expression to aid in converting H+12 intensities to any subsequent time. For precise conversions, particularly within one to two days after a given event, 

the above expression should be used. 

97 
7 1111111 

T 

TA 

OIABLO 

BOLTZMANN -

Plumbbob 

10 102 103 

Time After Burst (hours) 

Figure II-l. Fallout Decay Comparison 

98 
TABLE II-6 

FACTORS TO CONVERT H+lZ INTENSITIES TO INTENSITIES ON SPECIFIC DATES 

Date * 1 JULY AUGUST SEPTD1BER 

Shot 15 17 19 21 23 25 27 29 31 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 1 3 

.004 .004 

.005 .004 

.007 .007 

.022 .018 

.12 ,084 II .20 .12

,003 .003 .003 ,003 .0031 

.003 .003 .003 .003 

.004 .004 .004 .004 

.007 .006 ,006 .005 

.012 .Oll .OlO .009 

,014 .012 .Oll .OlO 

.29 .15 .lO ,068 

NOTE: Dates shown are based on 24-hour increments after Ht12. For more precise conversions, use the method described in the text. 
100 
APPENDIX III 

FILM BADGE DOSIFIETRY 

X-ray or photographic film, after exposure to ionizing radiation, 

shows an increased optical density upon development, The sensitivity of 

the film to such radiation is a function of the exposure intensity up to 

the saturation level of the film. Greater intensities serve only to 

reduce the developed optical density, a process called solarization. The 

degree of sensitivity depends on radiation type, radiation energy, and 

film type. 

Film is quite sensitive to incident electrons and photons but 

essentially insensitive to incident neutrons. Figure III -1 shows the 

response to saturation of DuPont Type 502 film for three different incident photon energies. It is possible to develop a series of such curves 

for various energies and, normalizing to the response of a particular 

energy radiation (usually that of Co 60 at 1.25 MeV), obtain the relationship of film response to an exposure in roentgens for the entire 

useful photon spectrum. This relationship is not unique but is instead 

an envelope of values, since the shape of the film sensitivity curve is 

not quite the same for all energies. The film response to roentgen 

exposure as a function of energy is given in Figure 111-2. Note that the 

film is much more sensitive than the roentgen measure to photons below 

a few hundred keV. This is because the film contains higher Z materials 

than air and, thus, possesses a much higher photoelectric cross section. 

On the other hand, in the region of dominance of the Compton cross 

section, the ratio of film response to roentgen response is at or near 

unity. 

Because of non-uniform sensitivity among film types, film 

badges usually contain two or more film types, one for low exposures, one 

for high exposures, and, sometimes, one for mid-range exposures. The 

exact sens itivity range of each film type determines the quality of the 

101 
-- 

6 

1.0 

Exposure (Roentgens) 

Figure III-l. DuPont Type 502 Film, Typical Response Curves. 

(Reference 12) 

102 

I 
Photon Energy (MeV) 

Figure III-Z. Typical Photon Kesponse for Bare DuPont Type 502 Film Packet 

Showing Limits for Two Net Film Densities. (Reference 13) 
reading in the region of overlap between film types. The films are enclosed 

in a paper container similar to that used for dental x-rays. This is further 

contained in a thin plastic case, usually with an opening on one side. The 

badge is usually worn on the chest with the opening facing away from the 

body. 

Because of the film's proclivity to over-respond to low-energy photons, a metallic shield is usually placed on the outside of the paper container before it is placed in the plastic case. This shield is so thin that 

it has little effect on high energy photons but is capable of making a substantial reduction of the low-energy photon response of the film badge. 

Two types of badges were employed during Operation Plumbbob and 

Exercise Desert Rock VII and VIII (Reference 14); one by Reynolds Electrical Engineering Co. (REECO) and the other by Lexington-Blue Grass 

Army Depot. REECO badges were issued to military and civilian scientific teams, and to AEC and AEC-contractor personnel. Lexington badges 

were issued to Desert Rock units participating in the tests. Both badges 

were based on the DuPont Type 559 film pack, the low and high dose film 

components of which were Types 502 and 606, respectively. The REECO film 

pack was shielded with a lead clip of dimensions l/2 x 1 x 0.0283 in. 

thick, covering opposing sides (Reference 14). Photon exposure was 

determined from film density recorded under the lead clip. 

The Lexington-Blue Grass Army Depot film packet was produced with 

four regions of dosimetric interest (Reference 15). The first was unshielded; the second and third were shielded front and back with aluminum 

and copper disks respectively, each 9/16 in. diameter and 0.040 in. thick; 

and the fourth region was shielded front and back with a lead-tin laminate 

disk 9/16 in. diameter with 0.042 in. Sn and 0.012 in. Pb, the lead being 

closest to the film. In the complex reading scheme used by Lexington, 

opacity readings from the four regions were recast as ratios to one of 

the four. By simultaneous analysis of these ratios, exposures from photons 

of descending energy were effectively "peeled off" until the lowest energy 

104 
x-rays and beta particles were accounted for. In general, the highest 

density filter (Pb/Sn) dominated the measurement of photons in the 

region above ~30 keV. The response relative to Roentgen exposure of 

the lead shielded low range (Type 502) film under the Pb/Sn shield is 

shown in Figure 111-3. 

Each batch of film was calibrated separately to establish density 

versus exposure in a fully assembled badge configuration. Badges were 

exposed to known intensities of normally incident photons from Co 60 

(1.25 MeV) and, in the case of Lexington Depot, other photon energy 

sources. Development chemistry, duration and temperature used to process film exposed in the field duplicated that used in the calibration. 

According to Lexington Depot (Reference I5), the probable 

accuracy to which the film density could be read in 1957 was about 50 

percent for exposures near the density crossover of the low and high 

range film components, while accuracy as good as ten percent in the 

low density range of each film could be expected. For exposure to gamma 

radiation, this crossover occurred between 8 and 10 roentgens. 

According to REECO (Reference 14), during the period from 17 

January 1957 to 17 October 1957, the process used for the analysis of 

the film components gave an exposure range of 20 mr to 10 r for the 

Type 502 film and 5 r and up for the Type 606. REECO agrees with the 

10 percent reading accuracy given by Lexington for the nonoverlap region, 

but asserts that any reading error in the overlap region could not be 

greater than about 2 r, or between 20 and 40 percent. 

Film badges were calibrated by exposure to normally incident 

radiation from known sources in the absence of the body mass in close 

proximity to which they are normally employed, This neglects the shielding provided by the body to radiation incident over approximately half 

the available angles of approach to the badge (assuming that the film 

badge is worn on the chest) and the contribution from backscattered 

radiation from the body. Because badge shielding brings the low energy 

(30 - 300 KeV) into line with the roentgen response, one can surmise 

that the dominant effect from the presence of the body would be that of 

105 
0.001 0.01 0.1 1.0 10 

Photon Energy (MeV) 

Figure 111-3. Lexington Blue Grass Army Depot Pb-Sn Shielded Type 502 

Film Response Relative to Roentgen Response (Reference 13) 
shielding; hence, the badge reading would indicate a lower exposure 

than the free-in-air tissue dose under the same exposure conditions. 

To assess the in-situ response of the film badges of interest, 

radiation transport calculations were performed using an adjoint Monte 

Carlo technique (Reference 22) and a man phantom model previously developed for Defense Nuclear Agency (Reference 16). The man phantom model 

represents an average Western male, 5 ft 8-l/2 in. in height and 

weighing 154 lbs. In this technique photons are started in a region of 

interest (in this case the film badge), sampled from a given energy 

distribution (the bare film badge response), and followed as they move 

backward in time and space and upward in energy until they escape the 

film badge-phantom region entirely. As they escape they are tallied 

by energy and angle. The result is a weighting of the sample response 

of the film badge due to the presence of the transport medium, the man 

phantom. That man phantom model is shown in Figure 111-4. The film 

badge was not modeled explicitly but was taken to be a point 0.09 cm 

from the surface of the chest, 20 cm down from the top of the torso, 

and 10 cm to the right of midline. 

The results of the radiation transport calculations are shown 

below for the Lexington Blue Grass Army Depot film badges. Response 

factors are given for the photon energy bands used in the calculation. 

Film Badge In-Situ Response/Roentgen Exposure 

Normalized to Co 60 (1.25 MeV) at Normal Incidence 

.70 , .64 , .67 , .71 , .66 , .77 , .78 , .@ , 

.l .15 .3 .45 .7 1.0 1.5 2.0 3.0 

Photon Energy (MeV) 

These results apply specifically to readings from the low range film at 

low opacity readings (~0.5). Such readings are typical of those recorded 

for members of military units participating in the Desert Rock VII-VIII 

exercise. No calculations have been performed on the REECO configuration. 

107 
Figure 111-4. The Adult Man Phantom 

108 
There are some uncertainties associated with the response 

factors. Each is accurate to an estimated 5 percent based on the 

statistical nature of the transport calculations. Some angular dependence of esponse results from the variation of effective filter 

thickness with angle of photon incidence. For typical gamma ray 

energies, this effect is minimal. There is no angular dependence for 

the film tself because the increased photon path length in the film 

at grazing incidence is exactly offset by the loss of projected badge 

area. 

Precise use of the in-situ response factors required knowledge 

of the energy distribution of the incident gamma rays. The fallout 

gamma spectrum is weapon- and time-dependent. A sample fission product 

spectrum is shown in Figure 111-5. Scattering of the gamma radiation 

occurs in air and as dependent on ground roughness. The scattered 

photon flux may be of the same order as the uncollided photon flux. 

Therefore the spectrum as detected by the film badge will have a significant component down into the low 100 keV range (References 18 and 19). 

In.order to utilize the in-situ response factors in the absence 

of spectral information , an average value must be determined. For any 

realistic gamma spectrum, a response factor of .70 is accurate to 

within 10 percent. Therefore .70 will be used to transpose between 

free field and film badge exposure. This conversion factor is applicable to the gamma radiation incident on a film badge worn on the chest 

of a person standing upright in a uniform fallout field. 

109 
0.3 

6

w 

& 

2 

LL 0.2 

2 t 

;z

=t 

LA

a: 

0.1 r 

0 I I I I I I 

.Ol .03 .1 .3 1 3 

PHOTON ENERGY (MeV) 

FIGURE 111-5. Relative Spectral Structure of Fission Product 

Photons (Reference 17) 

110 
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.