as the peroxide by addition of H,9,- FLOW SHEET FOR RECOVERY & PURIFICATION OF PLUTONIUM oxide was converted to nitrate (4 valence state) Cobia kK Be Mg CaS BatCeEe| WU Me FeCu ag Zn Me Sa E570 Or APnm Soin and was given to the Dry Chemistry Group for flu- NaOH in Ercess eee Sol'n of haMaK, Beery BO, 395 CAs Mots, WOEZn0gS035 4.P.S.F 51 Br,| oa Pee of Rs Bro on ed af 419 CaSe det ry lau areFeCags ede 7, Cp Ge solutions were reduced with so, and precipitated by NH,OH fo Prt of 4-6 treatment with A1(0H), Sel'n of MoCo, Sr, 84 Py of Purch Br rrendes af Ce.Ld.Te, Some Pu. Cb Ta,U,Ma Fe CoM MC. 4g,M5, ZF, In retrospect, it may be reasoned that the greatest exposures occurred in step e when H,0, was aq oe NH,0H in Excess Sofn of Co,Ni,Cu, Ag PUORLG Hydrondes of Cala, Tau Mn fa, Wg fe Th added (with vigorous stirring) to high concentra- Same Pu 4 wt OO, Sol'n cf Above Hydrandes _SOatHE Secret TageTri) b,Ta,U,'dn, Fea) Some Pu st Put ftem tions of plutonyl nitrate (1 to 40 grams per liter). Meth * He Oy Ke MF == Sarnot Th vial [son t eti, Ti,“ VKaPurey Gata, UbnnaCh (Kalinadsre, Zr. th Some Pu Some {| Pu 1 bm Hy 504 HNO, FUME yO NeBrOs Cela, 2e,Tr Cein7,Cp, | Although this procedure was carried out in an open Pul, Ta Mo,Fe, HRD Sol'n of Sulghates of Pu.CeLad ZATA) NH,OH hood in 3-liter cooled beakers, there was consider- Peticten RIOs ("AngmzeJ Sol'n of v.CeLe(Zr,Th) hNO,* Nabro, Pu(OH}, 17 the recovery procedure, but this also coincided in onAF] i* [Sone a KO, Ped, time with the increasing amounts of plutonium being noted, NaPyO,45,, Ce LaTazr) HNO, ] a { (Ceo ta2r} Soma Put, {Ce Lathzry handled.) ] a amar Extract on ‘ y to Puntieaton—— (The number of high nose counts in- creased sharply when the peroxide step was added to 2 Zr,Th) oo (Ce.LaTh zr} Nad > SHO ae ew Seedae ean + respirators. PuOy CrileGh29 POT CTR ara rH OH In April and May 1945, this pro- cedure was often carried out by workers wearing Wa, $3, , Heal Sucernatont Some Pu able fizzing and discharge of droplets into the air outside the hood. HNO, ( In December 1944, this process was turned over to another group (CM-10). HNO, Cato, . HNOS Late in 1944, the dilute supernatant orination. Some Pu nN, The plutonium MgO, 5Le) bale HNO, of dilute supernatant solution (0.1 to 1.0 gram per liter) also caused heavy fogging and occasionally Spattering. or ——te Purification The addition of NaOH to the large vats Because of the size of the 50-liter containers, this procedure was carried out in the open laboratories without benefit of hoods. Fig. 5. 3 Flow sheet for the recovery operation. This gives the general outline of the procedures used, but each individual recovery operation required special conditions. Other chemical steps which caused airborme contamination were concentrating dilute solutions by boiling; ashing combustible materials; and fusion procedures, especially those involving sodium peroxide plus earbon or persulfate. eee As might be expected, in the atmosphere of plutonium were dissolved directly in HCl; insoluble excitement, tension, and fatigue that prevailed salts during the closing days of the war, the Recovery (oxides or carbides) also were dissolved in acid after persulfate or carbonate fusion; (b) plutonium was precipitated with NaOH or NHOH; (c) pluto- nium hydroxide was dissolved in HNO, and precip- Group had its share of accidents which undoubtedly contributed to the exposures. The most dramatic of these occurred in May 1944 when the first 8-gram itated as the oxalate in the presence of reducing batch (the world's entire supply at that time) of agents; purified plutonium was being processed. (d)} plutonium oxalate was redissolved in An initial HNO, and oxidized to the hexavalent state by treat- 3.6-gram aliquot of plutonyl nitrate in solution, ment with NaBrO,; placed in a glass thimble prior to Soxhlet extrac- (e) ether extraction similar to that used in the purification process described tion, was heated in an oven. later (steps d and e), which involved extraction moved, the glass tray supporting the thimble broke from acid solution (in the presence of ammonium nitrate) and subsequent reduction with iodide and precipitation as the oxalate; and (f}) after April and the concentrated solution spilled on the floor. 1945, the plutonium was extracted into ether and reduced to the tetravalent state and precipi tated As it was being re- The spilled material was aspirated by mechanical suction, and the remaining plutonium was recovered from the contaminated asphalt tile slabs tom up from the floor. When recovered and purified, this