TABLE 11 RECOVERY OF KNOWN . Sumber oo AMOUNTS OF PLUTONIUM FROM REGULAR AND MOCK URINE SAMPLES ) Determinations Nature of Samples 94 88-100 Mock urine solucion 93 85-101 ra Regular urine 88 73-104 } Regular urine 95 81-105 ‘ Mock urine solution 11 MPLE 29. In a fur- Health Pass Ward for sample collection. eogae art. 4 2.2 4.3 to reduce costs, the Health Pass Ward ther «tfort wan abolished to collect in 1951, and employees were asked at home 2 morming and 2 evening void- These samples were pooled and considered inys. 3.4 the “equivalent' 24-hour urine sample. O.1 2.2 A reusable . exposures ), and this able IT) nformation of fore, The metal kits proved eventually to be There- a disposable cardboard kit containing four ay health ted to the ote = AEERa cage© procedure tion per minute. In 1955, an alkaline earth phos- phate precipitation was used directly on urine samples to concentrate plutonium, eliminating the Need to evaporate large volumes of urine. This recoveries or blanks. ysis of samples collected by this means suggests The desire for greater sensitivity resulted that a “true'�� 24-hour sample is not necessarily in adoption in 1957 of the Hanford procedure. collected. this method, plutonium is separated by TTA extrac- The pooled samples represent the urine In voided over a period of 22 + 4 hours when collected tion, and the final radiometric measurement is made correctly. by NTA (nuclear track alpha) This collection procedure is used today. film counting. The Hanford procedure afforded plutonium recoveries of been collected in special containers with time marks 70 + 17 percent with blanks of 0.007 + 0.005 dis- on the lids in an effort to learn more about the integration per minute. constancy of plutonium urinary excretion. chemical separation procedure utilizing anion ex- Informa- A somewhat simpler radio- tion gained from analysis of such timed samples has change was substituted in 1963. made it possible to apply corrections by volume and electronic equipment capable of pulse-height dis- Introduction of specific gravity so that results expressed in dis- crimination made it possible in 1967 to include a integrations per minute per sample can be realis- step utilizing 2365, as a tracer or yield-determiner. 2 In June 1972, feo was substituted for 23654 to 23854 and 239-240), | reduce the background in the corrected to disintegrations per minute per regions. ami ¥ ap- phosphate-lanthanum fluoride co-precipitation tech- l-pint bottles was introduced in January 1958; a dav, ANCES counter By 1949, the serial bismuth statistical review of the results obtained by anal- the early per min~ tion per minute. change in procedure did not alter the measured tically ecovery Suggest that plutonium recovery was 82 + 19 percent associated with blanks of 0.69 + 0.53 disintegra- 20 percent with blanks of 0.15 + 0.1 disintegra- l-pint bottles, which were discarded Since 1969, occasional nonroutine samples have em of Existing data from that time tained three ings in three bottles proved unacceptable. is been cupferride complex. nique was in use, affording recoveries of 67 + after use. our samples an after a plutonium separated by co-extraction with an iron- metal kit was furnished the employee; each kit con- unsanitary, and the concept of collecting 4 void- ght voidings zh bathing (O-1.2 cpm) (average 0.5 cpm) Blanks (regular urine) le (cpm ospital Spread : (4) Recovery ; (A) Amount of Spike (cpm) f The procedure, in use today, affords an RALTOCHEMICAL SEPARATION METHOD OF URINARY ASSAY overall recovery of 80 + 20 percent as determined FOR PLUTONIUM by internal spiking with To the best of our knowledge, as of January 1944, urine samples were ashed and the alpha activity of the ash was measured directly.” However, we knuw that in 1945 urine samples were ashed and the RADIOMETRIC MEASUREMENT The measuring device used in 1944 was a gas flow proportional alpha counter of unknown efficiency 25