RE: H-3 production (follow up to C-14 production)

["Morgan, Ben" <ben.morgan@pgnmail.com>]

Greetings:



American National Standard ANSI/ANS-18.1-1999, "radioactive source term

for normal operation of light water reactors", shows the tritium

concentration in reactor coolant as 1.0E-02 uCi/g for BWRs and 1.0 uCi/g

for PWRs.



Unlike BWRs, PWRs use boric acid in the coolant as a form of reactivity

control. This produces tritium from B10(n,2a)T and B10(n,a)Li7(n,na)T

reactions.



The pH of the PWR coolant is controlled by the addition of LiOH which

contains primarily Li7. This produces tritium by the Li7(n,na)T

reaction.



NOTE: There are also B11 and Li6 reactions that produce T but these are

negligible contributors.



Regards,



Ben



ben.morgan@pgnmail.com

 



Franz Schoenhofer

PhD, MR iR

Habicherg. 31/7

A-1160 Vienna

AUSTRIA

phone -43-0699-1168-1319



Dale,



Thanks for the calculations, how accurate or inaccurate they might be.

They confirm my comment, that production of C-14 (and tritium) is very

low in a reactor and therefore it is clear, that no elevations for those

radionuclides were found in precipitation and aerosols in Europe, not

even in the most affected countries, like Austria was. I know, what I am

talking about, because we have done the measurements in my laboratory

for Austria. Some laboratories reported elevated tritium values, but it

was found, that they misinterpreted I-131 contamination for tritium

and/or C-14. 



I remember from a seminar a long time ago a comparison of C-14 and T in

different reactor types, found in the containment air. They were

significantly different in PWR and BWR, but I do not remember any

numbers. When I asked the presenter for the reason he said that he did

not know. 



I do not believe, that the nitrogen and oxygen reactions are of much

importance - first of all, because there would not be nitrogen present,

secondly I wonder about the isotopic abundance of O-17. 



Best regards,



Franz

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