material was combined with more newly purified tion of the air lines was suspected, but an im plutonium, and the 8-gram sample, in the form of tigation by CM-12 has failed to show appreciab: the hydroxide, was placed in a centrifuge tube. contamination. While being centrifuged, the tube broke, ** Better respirators must be obtained quickly. The air pressure is being incre spilling the sample into the centrifuge cup and Improvements in the handling of product are be into the centrifuge itself. made, but it will be some time before the haza The plutonium was recovered once again by repeatedly washing the in- be appreciably reduced except by the use of be side of the centrifuge with a dilute acid soiu- protective devices. tion ene e** of improvements such as installation of a new Surprisingly, very little pluto- nium was lost in these two accidents. CM-1 has helped with a nu studies on improving the ventilation, installa In addition to these spectacular accidents, there were also occasional spills of large volumes of foot-pedal sinks, etc. The situation is st critical, however." (up to 50 liters) of dilute plutonium solution (5 to 10 mg) onto the floor. trated solutions were handled in stainless steel hoods.) Four of the 14 subjects cut their hands with contaminated objects; fortunately, in each case, the excised activity. tissues All 14 subjects were removed in the summe (The smaller concen- contained little radio- One other man burned his hand while carrying out the carbon-sodium peroxide fusion procedure. 1945 from this type of work because urine assz indicated that their body burdens were approac or had exceeded the then maximum permissible = (7 counts per minute per 24-hour urine specime suggesting a body burden of 1 Ug or 0.06 Ui). B. Three of our subjects worked in the Puri- As might be expected, exposures during the late spring and summer caused great concern about the health of these workers. The following excerpt is taken from the Monthly Progress Report of the Chemistry and Metallurgy Division for May 1945 (issued Purification Operation tion Group in the Chemistry and Metallurpy Re: Division. of purifying by wet chemical methods the plut: Produced by the piles in Oak Ridge and later Hanford. June 1, 1945): This group was given the responsib: Because it was believed that nonmet impurities could best be removed by subsequen "The health situation in the recovery laboratories has become much worse in the past month due chemistry procedures (see next section), this concentrated on removing contaminating metals The flow sheet used in the purification to the great increase in amount of product which is being processed. The trend in 24-hour urine counts is definitely upward. Because of this situation and because shutdown of recovery will essentially shut down purification, as well as increase holdup of product, every effort is being made toa improve the health situation. Forced air respira- tion? until July 1945 is shown in Fig. 6, Pl nium nitrate slurry received in 160-gram lots metal containers from Hanford was dissolved, diluted (cut), assayed, and transferred (some with considerable difficulty) into a closed s On the average, these preliminary steps took tors have been put into use, although they have not 3.3 days. The following procedures were then materially altered the nose counts yet. ried out: (a) reducing pul (or Pur) nitrat Contamina- iodide; REREKKERK The reason for the accidents presumably was the unsuspected radiation-induced fragility of the glass vessels used in these procedures. It was believed that alpha particles alone would not affect the glass, but irradiation by neutrons arising from interaction of alpha particles with boron in Pyrex glass had not been anticipated. ka RKRAK There is a story that great difficulty was encountered in the fluorination of this ill-fated batch of plutonium. We have not been able to verify this. (b) precipitating py ltl oxalate and d solving as put with bromate and nitric acid; (c) precipitating plutonium as sodium plutony acetate and dissolving in HNO 5 (d) ether ext ing plutonyl nitrate from the acid solution c ing ammonium nitrate; and (e) reducing pluton nitrate with lodide and precipitating as the late. This product, recovered in about 97 pe yield, was given to the Fluorination Group. rification of plutonium in this form continue