ML19296D534
| ML19296D534 | |
| Person / Time | |
|---|---|
| Site: | 07000984 |
| Issue date: | 01/11/1979 |
| From: | Kalkwarf D Battelle Memorial Institute, PACIFIC NORTHWEST NATION |
| To: | Crow W NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 8003050205 | |
| Download: ML19296D534 (2) | |
Text
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@BaTelle 2#
January 11, 1979 942-3809 2
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Mr. William T. Crow 1Cim U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards 7915 Eastern Avenue Silver Springs, Maryland 20906 9
Dear Mr. Crow:
I have assembled solubility classifications in the table below for the various dust samples that we collected last September on the grounds of the Allied Chemi-cal plant at Metropolis, Illinois.
Four samplers operating at 40 cfm were used for a total of 21.0 days at station 11 to collect dust containing 392 pg of 5
uranium from 4.8 x 10 cubic feet of air.
Dust having an equivalent aerodynamic diameter (EAD) 15.5 pm was collected in a cyclone preseparator above the filter and is designated NDil (for nonrespirable dust, station 11) in the tables below.
Dust having an EAD <5.5 pm was collected on a filter and is designated RDll (for respirable dust, station 11) in the tables below.
This resf rable fraction accounted for 52.2% c? the uranium collected at station 11.
Two samplers operat-ing at 40 cfm were used at each of stations 10 and 12 for 2.7 days.
Only the respirable fractions (EAD <5.5 pm) were collected and these were pooled and found to contain 905 pg of uranium.
Dust from this sample is designated RD02 in the sample below.
Portions of these samples were dissolved for 43 days in simulated lung fluid at 37 C; and periodically, the supernatant solution was re oved for uranium analy-sis and replaced with fresh fluid.
At the end of the 13 days, the solid residues were removed and analyzed for uranium by optical fluorescence, X-ray fluorescence and neutron activation analysis. Af ter the first dissolution c;ns were started, smaller portions of the initial samplec were dissolvec in sirJlated lung fluid at 37 C for a shorter total length of time in order tc :sst fc adsorption of dissolved uranium on to other solid material in the si~:les.
- n all cases, results were expressed as the fraction of uranium remii-ing un:issolved as a function of time; and the data were fitted by the co. : er to e:uations of the form:
F=fi exp (-0.693t/1 1) + f exp (-0.693t/T2) * ^ exp (-:.593t/T ) +...
2 3
In each case, an equation with three terns was found :: #i: :-e data within the experimental error in the measurements, indicating t*a: :-ree <anium species with different dissolution half-times, Tj, nad been ir :ne or':4nal sample.
- Also, in each case, these terms indicated two uraniuT species xiMi-ne D solubility classification of the ICRP Task Group Lung "odel anc :.e wi W
- ne Y classifica-tion.
The fractions of uranium components,;ithin these :lassi#ications are shown in the table below, and the fractions and exact dissels:icn rilf-times of the uranium components are shown in the following table.
U j
2
fir. Uilliam T. Crow January ll, 1980 i
Page ?
Solubili_ty_ Classification of Dust Colls::ed '! ear the Allied F ant Sample U in Portion Dissoluti:n.me Classification RDll-1 98.2 pg 43 d 0.350, 0.65Y RDll-2 43.0 lc 0.35D, 0.65Y RDll-3 12.3 14 0.510, 0.49Y f1011 -1 87.4 43 0.32D, 0.68Y flDll-2 39.2 14 0.41D, 0.59Y RD02 385.6 43 0.66D, 0.34Y j
Dissolution Half-Times of Uranium Com_ponents in the Collected Dust Sample f,T1 bl f,L i
3 RDll-1 0.24, 0.09d 0.11, 0.69d 0.65, 1861d RDll-2 0.23, 0.04d 0.12, 0.45d 0.65, 1668d RDll-3 0.30, 0.05d 0.21, 0.99d 0.49, 482d flDll-1 0.28, 0.18d 0.04, 1.53d 0.68, 3082d f1Dll-2 0.24, 0.09d 0.17, 0.41d 0.59, 3855d RD02 0.62, 0.05d 0.04, 1.22d 0.34, 281d Statistically, the 95% confidence limits on tnis data are generally within 15%
but the long half-times are evaluated much less precisely.
For example, for RDll-1, the 95% confidence limits are:
fi = 0.22 -
0.25, Ti = 0.08 - 0.10d f: = 0.09 -
0.13, T
0.59 - 0.83d
=
2 f = 0.649 - 0.654, T
1292 - 3325d
=
3 3
I will try to issue a more complete report c
- .W.is work as rapidly as possible and will look forward to meeting with you ar: ?.ne representatives from Allied Chemical Company within the next few weeks.
Sincerely yours,
'5>ad] S. fb!L !
l Donald R. Ka l kwa r f, Ph. D.
Chemical fiethods and Kinetics Physical Sciences Department
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