ML19256D248
| ML19256D248 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/16/1971 |
| From: | Burley G US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910170760 | |
| Download: ML19256D248 (2) | |
Text
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AFP 16 r-P. A. Morris, Director, DRL g,,,
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T. R. Wilson, Assistant Director, DRL8 f DOSE CALCULATIOFS FOR T11REE MILE ISLAND 1
We have calculated the thyroid dose for the %ne Mile Island I nuclear reactor, using a number of diffemnt asstasptions sander review for possible use in the DRL revision of spray system effectiveness. Wis review is not complete and the sttached calculations are for your information.
A number of possible variations have been considered. We present here only the assumptions and usults for our current model and for the least conservative model currently under corJideration. For the latter, a numerical value of 5% organic (and other difficult to remove species) is probably appropriate;, but we have not yet developed the justification to defend this number at a public hearing.
We results are presented in tezas of thyroid doses. It should be noted that relatively large differeness in the removal constants (1) lead to smash smaller differences in the calculated doses. Further increases in the removal constaat for inorganic iodine would not substantially reduce these calculated doses. We magnitudes of the removal esastants for organte ledides ar.d for particulate associated iodine are similar to the optimum values suggested by ORNL.
We results presented here are preliminary, but indicative of the variation possible. Our arrent calculational technique introduces cesservatism of less than a factor of two.
it. view of experimental and calculational uncertainties, it seems desirable to maintain a margin sf ry-imately this magnitude in our dose guidelines.
Cordon Burley, Site-Environmental 4 Radiation Safety Group Division of Reactor Licensing Enclosures Droe Mile Island Dese Calculations 1450 0%
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R. DeYoung I* I N DRL zv.'.f.
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Foren AIC.3Ie (Rev. 9.H) AECM 0240 m a a.' san.ast reien as.rers i issa o-se.wi?
7910170 N O A
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111REE MILE ISLAND 1 s
s DOSE CALCULATIONS Meteorology:
Type F 1 meter /sec Leak Rate:
0.2%/ day 1.
Current Model:
85t. inorganic 1 = 4.1 hrs-I
= 0.35 hrs-1 (non-con-10% organic 1
senatin) 5% particulate A = No removal 2 hr thyroid dose = 330 rem 2.
Realistic Reduction Factors (little or no conservatism in calculational model) a.
Same division of iodine into fractions as current model
-I 85% incrganic 1 = 9.5 hrs 10% organic A = 0.17 hrs" 5% particulate A = 0.70 hrs-1 2 hr thyroid dose = 231 rem b.
Smaller fraction of Organic Iodide
~I 90% inorganic 1 = 9.5 hrs 5% organic A = 0.17 hrs ~I
+
5% particulate A = 0.70 hrs-I 2 hr thyroid dose = 174 rem 1450 093
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