Skin Response To A Point Source Of Fissioned U-235 Carbide

Development of nuclear rocket propulsion engines poses a potential skin exposure problem. Presently, fuel elements in these engines are composed of about 1012235UC2 microspheres 100–200 μ in diameter. Fuel element pieces (a few microns to full size particles) may be ejected from the engine during operation in or reentry into the atmosphere. Such particles may have undergone 108-1013 fissions and have surface dose rates of 103-108 rads/hr. This paper presents results of several experiments performed to evaluate immediate or short-term skin response to fissioned 235UC2 particles. Particles delivering integrated surface doses of 6600 to 2,500,000 rads with exposure times of 3–6 hr have been placed on the back of monkeys, and the progress of the lesions has been observed clinically and histologically. Skin lesions produced by integrated surface doses of 97,000 to 215,000 rads have been observed on one human subject. Responses ranging from mild erythema to ulceration of monkey skin and from mild erythema to questionable or slight dry desquamation of human skin have been observed.