DOSIMETRY ANALYSIS OF PARTICIPANTS IN PROJECT TRINITY
This chapter summarizes the radiation doses received by participants
in various activities during Project TRINITY. The sources of this
dosimetry information are the safety and monitoring report for
personnel at TRINITY, which includes a compilation of film badge
readings for all participants up to 1 January 1946, and film badge
data from the records of the Reynolds Electrical and Engineering
Company, which contain readings through 1946 (1; 16). These sources
list individual participants with their cumulative gamma radiation
exposures.
4.1 FILM BADGE RECORDS
During TRINITY, the film badge was the primary device used to measure
the radiation dose received by individual participants. The site
monitoring plan indicates that film badges were to be issued to
participants. The film badge was normally worn at chest level on the
outside of clothing and was designed to measure the wearer's exposure
to gamma radiation from external sources. These film badges were
insensitive to neutron radiation and did not measure the amount of
radioactive material that might have been inhaled or ingested (1).
Personnel from the Medical Group had responsibility for issuing,
receiving, processing, and interpreting film badges for Project
TRINITY. The Site Monitoring Group compiled the film badge records
for both onsite and offsite personnel. Radiological safety personnel
and military police recorded the names and identification numbers of
individuals as they entered the test area. This information was
recorded in an entry logbook and on a personal exposure data card.
Upon leaving the test area, individuals returned their film badges to
the check station. When the film badges were processed and
interpreted, the reading was entered on the individuals exposure data
card. In this manner, the number of times an individual entered the
test area and his cumulative exposure history were recorded and
maintained (1).
4.2 GAMMA RADIATION EXPOSURE
The safety and monitoring report lists film badge readings for about
700 individuals who participated in Project TRINITY from 16 July 1945
to 1 January 1946 (1). This list includes both military and
nonmilitary personnel who were involved with the TRINITY operation and
postshot activities. However, records are available for only 44 of
the 144 to 160 members of the evacuation detachment (1). In addition,
some of these film badge listings may be for personnel who were only
peripherally involved with TRINITY activities, such as family members
and official guests who visited the site.
According to the safety and monitoring report, by 1 January 1946, 23
individuals had received cumulative gamma exposures greater than 2 but
less than 4 roentgens. An additional 22 individuals received gamma
exposures between 4 and 15 roentgens. Personnel who received gamma
exposures exceeding 2 roentgens represent less than six percent of the
Project TRINITY participants with recorded exposures. As described
below, these exposures generally resulted when personnel approached
ground zero several times (1).
Information is available regarding the activities of some of these
personnel. One of the drivers of the earth-sampling group's
lead-lined tank, an Army sergeant who traveled three times to ground
zero, received an exposure of 15 roentgens. A second tank driver,
also an Army sergeant, received an exposure of 3.3 roentgens. Three
members of the earth-sampling group, all of whom traveled in the tank
to ground zero, received exposures of 10, 7.5, and 5 roentgens. An
Army photographer who entered the test area six times between 23 July
and 20 October received 12.2 roentgens (1).
Four individuals involved with excavating the buried supports of the
TRINITY tower from 8 October to 10 October 1945 received gamma
exposures ranging from 3.4 to 4.7 roentgens. Film badge readings for
this three-day period indicate that the two individuals who operated
mechanical shovels received 3.4 and 4.3 roentgens, while the two who
supervised and monitored the excavation received exposures of 4.2 and
4.7 roentgens. The individual receiving 4.7 roentgens during the
excavation operation had received 1.3 roentgens from a previous
exposure, making his total exposure 6 roentgens (1).
An Army captain who accompanied all test and observer parties into the
ground zero area between 1 September and 11 October 1945 received a
total gamma exposure of 2.6 roentgens (1). The activities and times
of exposure are not known for other personnel with exposures over 2
roentgens.
According to the dosimetry records for 1946, about 115 people visited
the test site that year. No one ventured inside the fence surrounding
ground zero, and no one received an exposure greater than 1 roentgen
(1; 16).
REFERENCE LIST
The following list of references represents the documents consulted in
preparation of the Project TRINITY volume.
AVAILABILITY INFORMATION
An availability statement has been included at the end of the
reference citation for those readers who wish to read or obtain copies
of source documents. Availability statements were correct at the time
the bibliography was prepared. It is anticipated that many of the
documents marked unavailable may become available during the
declassification review process. The Coordination and Information
Center (CIC) and the National Technical Information Service (NTIS)
will be provided future DNA-WT documents bearing an EX after the
report number.
Source documents bearing an availability statement of CIC may be
reviewed at the following address:
Department of Energy
Coordination and Information Center
(Operated by Reynolds Electrical & Engineering Co., Inc.)
ATTN: Mr. Richard V. Nutley
2753 S. Highland
P.O. Box 14100
Las Vegas, Nevada 89114
Phone: (702) 734-3194
FTS: 598-3194
Source documents bearing an availability statement of NTIS may be
purchased from the National Technical Information Service. When
ordering by mail or phone, please include both the price code and the
NTIS number. The price code appears in parentheses before the NTIS
order number.
National Technical Information Service
5285 Port Royal Road
Springfield, Virginia 22161
Phone: (703) 487-4650
(Sales Office)
Additional ordering information or assistance may be obtained by
writing to the NTIS, Attention: Customer Service, or by calling (703)
487-4660.
PROJECT TRINITY REFERENCES
*Available from NTIS; order number appears before the asterisk.
**Available at CIC.
***Not available, see Availability Information page.
****Requests subject to Privacy Act restrictions.
1. Aebersold, Paul. July 16th Nuclear Explosion-Safety and
Monitoring of Personnel (U). Los Alamos Scientific Laboratory, Atomic
Energy Commission. Los Alamos, NM.: LASL. LA-616. January 9, 1947.
170 Pages.***
2. Bainbridge, K. T. Memorandum to All Concerned, Subject: TR
Circular No. 18--Total Personnel at TR. [Base Camp, Trinity Site:
NM.] July 3, 1945. 1 Page.**
3. Bainbridge, K. T. TRINITY. Los Alamos Scientific Laboratory.
Los Alamos, NM.: LASL, LA-6300-H and Washington, D. C.: GPO. May
1976. 82 Pages.**
4. Bramlet, Walt. Memorandum for Thomas J. Hirons, Subject: DOD
Participants in Atmospheric Tests, wo/encl. Los Alamos Scientific
Laboratory. Los Alamos, NM. ISD-5. February 20, 1979. 4 Pages.**
5. General Electric Company--TEMPO. Compilation of Local Fallout
Data from Test Detonations 1945-1962. Vol. 1: "Continental US Tests."
Washington, D. C.: Defense Nuclear Agency. DNA 1251-1(EX.). 1979.
619 Pages. (A99) AD/AO79 309.*
6. Groves, Leslie R., LTG, USA. Memorandum for Secretary of War,
[Subject: TRINITY]. [Washington, D.C.] 18 July 1945. 13 Pages.**
7. Groves, Leslie R., LTG, USA (Ret.). Now It Can Be Told: The Story
of the Manhattan Project. New York, NY.: Harper and Row. 1962. 444
Pages.
8. Headquarters, 9812th Technical Service Unit, Provisional
Detachment No. I (Company "B"). [Extract from: Daily Diary,
Provisional Detachment No. 1 (Company "B"), 9812th Technical Service
Unit.] Army Corps of Engineers, Department of War. [Santa Fe, NM.]
14 July 1945. 2 Pages.**
9. Headquarters, Special Service Detachment. Supplemental Special
Guard Orders, with Appendix. Los Alamos Scientific Laboratory,
Manhattan Engineer District. [Alamogordo, NM.] 14 July 1945. 4
Pages.**
10. Hempelmann, L. H., M.D. [Extracts from: "Preparation and
Operational Plan of Medical Group (TR-7) for Nuclear Explosion 16 July
1945."] Los Alamos Scientific Laboratory, Atomic Energy Commission.
Los Alamos, NM.: LASL. LA-631(Deleted). June 13, 1947. 32 Pages.***
11. Hoffman, J. G. [Extracts from "Health Physics Report on
Radioactive Contamination throughout New Mexico Following the Nuclear
Explosion, Part A--Physics."] Los Alamos Scientific Laboratory,
Manhattan Engineer District. [Los Alamos, NM.] [1945.] 31 Pages.**
12. Lamont, Lansing. Day of TRINITY. New York, NY.: Atheneum.
1965. 331 Pages.
13. Los Alamos Scientific Laboratory, Public Relations Office. "Los
Alamos: Beginning of an Era, 1943-1945." Atomic Energy Commission.
Los Alamos, NM.: LASL. 1967. 65 Pages.**
14. Oppenheimer, J. R. Memorandum for Group Leaders, Subject:
TRINITY Test. Los Alamos Scientific Laboratory. Los Alamos, NM.
June 14, 1945. 2 Pages.**
15. Palmer, T. O., Maj., USA. Evacuation Detachment at TRINITY.
[Manhattan Engineer District, Army Corps of Engineers.] [Los Alamos,
NM.] [18 July 1945.] 2 Pages.**
16. Reynolds Electrical & Engineering Company, Inc. [Personnel
Radiation Exposures, 1945, 1946] Las Vegas, NV. Microfilm.****
17. Warren, S. L., COL., USA. Directions for Personnel at Base Camp
at Time of Shot. Los Alamos Scientific Laboratory, Manhattan Engineer
District. [Alamogordo, NM.] 15 July 1945. 1 Page.**
18. Warren, S. L., COL, USA; Hempelmann, L. H., M.D. Extracts from:
Personal Notes, Subject: Events in Camp Immediately Following
Shot--July 16, 1945. 1945. 2 Pages.**
19. Weisskopf, V.; Hoffman, J.; Aebersold, Paul; Hempelmann, L. H.
Memorandum for George Kistiakowsky, Subject: Measurement of Blast,
Radiation, Heat and Light and Radioactivity at Trinity. [Los Alamos,
NM.] 5 September 1945. 2 Pages.**