July 1944 in the percent of laboratories in June and by swipes) which radioactivity levels (as measured were above 5000 counts per minute or were between 500 and 500Q counts per minute. high nose councs Table II shows the Cover 50 counts per minute) of three chemists in the Recovery Group (other nose counts of these men not included were consistently positive but below 50 counts per minute). In April This group was charged with the following responsibilities: plutonium which had been either left behind in any of the experimental or operational procedures or spilled accidentally or lost as contamination, and (b}) converting the recovered plutonium to the +4 valence state suitable for fluorination and subsequent reduction to plutonium metal. In 1944, the Recovery Group dealt first with 1945, 1243 "hot" (aver 500 counts per minute) spots, mostly detected by portable counters, were decontaminated. In June, July, and August 1945, the {a) recovery of the then priceless milligram and later with gram amounts of plutonium; however, in March 1945, as a result of increased number of decontamination procedures carried out quantities being processed by the Chemistry and were 1980, Metallurgy Division, the Laboratory began to handle 3489 (of which 760 exceeded 30,000 counts per minute), and 5347, respectively. Lest the kilogram quantities of plutonium. During peak work reader think that the operations were lax or care- periods, the staff worked 12-hour shifts 7 days a less, he should be advised that a large, weil- week. Fortunately, by this time new laboratory trained monitoring staff of approximately 41 persons facilities were in use in an annex of the old D worked overtime to maintain the safety standards Building. with the crude methods available. tained under reduced pressure} had replaced the Pressures to A suite of three laboratories (main- build the bomb were so great that work had to pro- single laboratory D-117. ceed using the best, although admittedly unsatis-— open Stainless steel hoods instead of the ordinary These laboratories had factory, safety measures of the times. chemical hoods previously used in D-il?. Although two of these laboratories were equipped with air IfI, PLUTONIUM OPERATIONS CAUSING HEAVY EXPOSURES Twenty-three of the 25 living exposed subkA . . jects worked in four operating groups: Pluto- nium Purification (wet chemistry), Plutonium Fluorination (dry chemistry), Plutonium Reduction (to metal), and Plutonium Recovery. Because the last operation was by far the most hazardous, it will be described first. masks were not entirely satisfactory in protecting personnel from airborne contamination. mitted in 1944 and 1945 (many still classified), as well as references 3 and 5, are the source of much of the material in this section. Extensive interviews with the subjects and their supervisors, as well as with the health monitors, provided sup- Not until July 1945, when a specially made mask (called the . KKKKKEK Kennedy-Hinch mask, after its designers) was developed, was there comparatively good protection against airborne radioactivity. The types of plutonium-containing materials Monthly reports of the Chemistry and Metallurgy Research and Health Divisions sub- submitted to the Recovery Group for processing included analytical residues; washings (supernatant solutions) from various steps in the wet purifica- tion of plutonium; metallic scraps, shavings, and trimmings: crucibles composed of various materials used in the reduction of PuF 4? absorbent materials used to wipe up accidental spills and other con- plementary information. A. lines, the commercially available positive+pressure ‘taminated materials; graphite tubes used in oxygen Recovery Operation analysis; and drybox and chemical hood sweepings. Fourteen af the 25 subjects with measurable body burdens of plutonium worked in the recovery operation between March 1944 and September 1946. After considerable experimentation, the following basic procedure was adapted for recovery opera. KKKKAKKK tions (see Fig. 5) : (a) soluble salts of RRAKKKK RAKKIK These men were the charter members of the UPPU Club formed by Wright Langham when this study began in the early 1950's. In essence, the acronym rep- resents the phrase ''you excrete plutonium." The name was originally IPPU, but Langham decided this Was too personal. The late Joseph W. Kennedy was the leader of CMR Division. KEKREKK EK It should be mentioned that not all of the recovered plutonium went through the entire procedure. Depending upon the chemical nature and purity of the plutonium being recovered, various steps of the total procedure were omitted. :