Appendix A: Category 2 Threshold Quantities of Radionuclides

DOE-STD-6003-96

APPENDIX A

CATEGORY 2 THRESHOLD QUANTITIES OF RADIONUCLIDES

Following is a list of radionuclides and their associated Category 2 threshold quantities as

defined in DOE 1992. This list was taken from RSAC-5f, a modified version of the Radiological

Safety Analysis Computer Program (Wenzel 1993). The RSAC-5 program was modified to cal-

culate doses for airborne releases of International Thermonuclear Experimental Reactor (ITER)

activation products (Abbott and Wenzel 1994). RSAC-5f used external dose conversion factors

from DOE 1988a and internal dose conversion factors from DOE 1988b. Some internal dose

conversion factors were taken from Fetter 1988 and 1991 for those radionuclides not covered in

DOE 1988b.

These threshold quantities were calculated in accordance with guidance in Attachment 1

of DOE 1992. Specifically, the following equation, taken from page A-6 of DOE 1992, was used:

Q = (1 rem)/[RF*SA*χ/Q*(CEDE*RR + CSDE)] ,

where

Q = quantity of material used as threshold (grams)

RF = Airborne release fraction of material averaged over an entire facility (unitless)

SA = Specific activity of radionuclide released (Ci/gm)

χ/Q = Expression accounting for dilution of release at a point under given meteorologi-

cal conditions (Specific Concentration) (sec/m3)

CEDE = Committed effective dose equivalent for a given radionuclide

(inhalation)(rem/Ci). Note: The CEDE for tritium (H-3) includes a 50% addi-

tion for direct skin absorption in addition to the inhalation pathway.

RR = Respiration rate, which is assumed equal to the standard value used for an

active man (3.5E-4 m3/sec)

CSDE = Cloud shine (immersion) dose equivalent (rem*m3/Ci*sec)

A χ/Q of E-4 was used as indicated in Attachment 1 to DOE 1992.

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