**The Project Gutenberg Etext of U. S. Project
Trinity Report**
by Carl Maag and Steve Rohrer
(Click here for original, unabridged source.)
by Carl Maag and Steve Rohrer
for the U. S. Defense Nuclear Agency, Department of Defense
June, 1996 [Etext #548]
/.../
CHAPTER 1
INTRODUCTION
Project TRINITY was the name given to the war-time effort to produce
the first nuclear detonation. A plutonium-fueled implosion device was
detonated on 16 July 1945 at the Alamogordo Bombing Range in
south-central New Mexico.
Three weeks later, on 6 August, the first uranium-fueled nuclear bomb,
a gun-type weapon code-named LITTLE BOY, was detonated over the
Japanese city of Hiroshima. On 9 August, the FAT MAN nuclear bomb, a
plutonium-fueled implosion weapon identical to the TRINITY device, was
detonated over another Japanese city, Nagasaki. Two days later, the
Japanese Government informed the United States of its decision to end
the war. On 2 September 1945, the Japanese Empire officially
surrendered to the Allied Governments, bringing World War II to an
end.
In the years devoted to the development and construction of a nuclear
weapon, scientists and technicians expanded their knowledge of nuclear
fission and developed both the gun-type and the implosion mechanisms
to release the energy of a nuclear chain reaction. Their knowledge,
however, was only theoretical. They could be certain neither of the
extent and effects of such a nuclear chain reaction, nor of the
hazards of the resulting blast and radiation. Protective measures
could be based only on estimates and calculations. Furthermore,
scientists were reasonably confident that the gun-type uranium-fueled
device could be successfully detonated, but they did not know if the
more complex firing technology required in an implosion device would
work. Successful detonation of the TRINITY device showed that
implosion would work, that a nuclear chain reaction would result in a
powerful detonation, and that effective means exist to guard against
the blast and radiation produced.
1.1 HISTORICAL BACKGROUND OF PROJECT TRINITY
The development of a nuclear weapon was a low priority for the United
States before the outbreak of World War II. However, scientists
exiled from Germany had expressed concern that the Germans were
developing a nuclear weapon. Confirming these fears, in 1939 the
Germans stopped all sales of uranium ore from the mines of occupied
Czechoslovakia. In a letter sponsored by group of concerned
scientists, Albert Einstein informed President Roosevelt that German
experiments had shown that an induced nuclear chain reaction was
possible and could be used to construct extremely powerful bombs (7;
12)*.
* All sources cited in the text are listed alphabetically in the
reference list at the end of this volume. The number given in the
text corresponds to the number of the source document in the reference
list.
In response to the potential threat of a German nuclear weapon, the
United States sought a source of uranium to use in determining the
feasibility of a nuclear chain reaction. After Germany occupied
Belgium in May 1940, the Belgians turned over uranium ore from their
holdings in the Belgian Congo to the United States. Then, in March
1941, the element plutonium was isolated, and the plutonium-239
isotope was found to fission as readily as the scarce uranium isotope,
uranium-235. The plutonium, produced in a uranium-fueled nuclear
reactor, provided the United States with an additional source of
material for nuclear weapons (7; 12).
In the summer of 1941, the British Government published a report
written by the Committee for Military Application of Uranium
Detonation (MAUD). This report stated that a nuclear weapon was
possible and concluded that its construction should begin immediately.
The MAUD report, and to a lesser degree the discovery of plutonium,
encouraged American leaders to think more seriously about developing a
nuclear weapon. On 6 December 1941, President Roosevelt appointed the
S-1 Committee to determine if the United States could construct a
nuclear weapon. Six months later, the S-1 Committee gave the
President its report, recommending a fast-paced program that would
cost up to $100 million and that might produce the weapon by July 1944
(12).
The President accepted the S-1 Committee's recommendations. The
effort to construct the weapon was turned over to the War Department,
which assigned the task to the Army Corps of Engineers. In September
1942, the Corps of Engineers established the Manhattan Engineer
District to oversee the development of a nuclear weapon. This effort
was code-named the "Manhattan Project" (12).
Within the next two years, the MED built laboratories and production
plants throughout the United States. The three principal centers of
the Manhattan Project were the Hanford, Washington, Plutonium
Production Plant; the Oak Ridge, Tennessee, U-235 Production Plant;
and the Los Alamos Scientific Laboratory in northern New Mexico. At
LASL, Manhattan Project scientists and technicians, directed by Dr. J.
Robert Oppenheimer,* investigated the theoretical problems that had to
be solved before a nuclear weapon could be developed (12).
* This report identifies by name only those LASL and MED personnel who
are well-known historical figures.
During the first two years of the Manhattan Project, work proceeded at
a slow but steady pace. Significant technical problems had to be
solved, and difficulties in the production of plutonium, particularly
the inability to process large amounts, often frustrated the
scientists. Nonetheless, by 1944 sufficient progress had been made to
persuade the scientists that their efforts might succeed. A test of
the plutonium implosion device was necessary to determine if it would
work and what its effects would be. In addition, the scientists were
concerned about the possible effects if the conventional explosives in
a nuclear device, particularly the more complex implosion-type device,
failed to trigger the nuclear reaction when detonated over enemy
territory. Not only would the psychological impact of the weapon be
lost, but the enemy might recover large amounts of fissionable
material.
In March 1944, planning began to test-fire a plutonium-fueled
implosion device. At LASL, an organization designated the X-2 Group
was formed within the Explosives Division. Its duties were "to make
preparations for a field test in which blast, earth shock, neutron and
gamma radiation would be studied and complete photographic records
made of the explosion and any atmospheric phenomena connected with the
explosion" (13). Dr. Oppenheimer chose the name TRINITY for the
project in September 1944 (12).
/,,,/
REFERENCE LIST
The following list of references represents the documents consulted in
preparation of the Project TRINITY volume.
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.**
End of The Project Gutenberg Etext of U. S. Project Trinity Report