The TR-7 or Medical Group, shown in the figure 1-5 organizational
chart, was responsible for radiological safety at Project TRINITY.
Many of the physicians and scientists in the Medical Group had worked
with radioactive materials before and were trained in radiological
safety procedures. The Chief of the Medical Group supervised the
radiological safety operations and reported to the TRINITY director.
In addition to providing medical care to TRINITY personnel, this group
established radiological safety programs to:

o Minimize radiation exposure of personnel on the test site and in
offsite areas

o Provide monitors to conduct radiological surveys onsite and offsite

o Provide and maintain radiation detection instruments

o Provide protective clothing and equipment.

An exposure limit of 5 roentgens during a two-month period was
established. Personnel were provided with radiation detection
instruments to determine their exposures (1).


3.1 ORGANIZATION

The Medical Group consisted of physicians, scientists, and
administrators, as well as radiological monitors. Many of these
personnel were nonmilitary, but all worked on the Manhattan Project
under the administration of the Army Corps of Engineers Manhattan
Engineer District.