Air concentration values (ACV)

DOE-HDBK-1184-2004

converted to actual activity by dividing it by the appropriate SAFβ or by otherwise

determining the total activity in the STPs in the sample. Then use either equation

5-10 or 5-11, to calculate the intake in terms of actual activity.

Next, using a computer code such as LuDEP, the CEDE can be calculated. The

component of the CEDE resulting from exposure to the lung would have to be

corrected for energy absorption using the appropriate SAFe in a manner analogous

to that in equation 5-9.

NOTE: If the base material and particle size are not known, parameters and

associated SAFs for the most conservative material (i.e., HfH2), 1 m

AMAD particle size (s g = 2.5), and Absorption Type S should be used for

dose computations. (See Table 5-7 for default assumptions.) [Absorption

Type S is believed to be sufficiently conservative: the DCFo for 1 m

AMAD polydisperse HfH2 is 4.29 x 10-10 Sv/Bqo (assuming Type S) and

4.85 Η 10-10 Sv/Bqo (assuming dissolution rates determined by Cheng,

1999a). This represents only a 13% increase of Type "Super-S" over

Type S.] Deviations from these parameters should only be allowed in

situations where material and particle size are well known.

As noted above, the variability of CEDE DCFo with material or particle size is not

great (range is factor of 5). Therefore, using a conservative assumption of material

and particle size distribution (1 m AMAD) is accurate within that factor for any

material or particle size distribution; this assumption can be readily implemented

when air monitoring is the method of intake assessment. A factor of dose

overestimation (~ 10 - 100) is further applied when all captured tritiated particulates

are assumed to be Type S and are measured by LSC.

5.2.4.2 ACV's for ITPs

Air concentration values (ACV) can now also be computed; these are

concentrations of tritiated particulate aerosols which, when inhaled, impart

prescribed doses over a given time (i.e. 0.05 Sv in 200hrs).

Derived Air Concentrations (DACs) in 10 CFR Part 835 are derived from EPA

Federal Guidance Report No. 11. Neither EPA Report No. 11 nor 10 CFR Part 835

specifically addresses DACs for ITPs. DOE Radiological Control Technical Position

99-02 addresses development of ACVs for ITPs, which may be used in lieu of

regulatory DAC values until such values are developed and codified. ACVs are

concentrations of tritiated particulate aerosols which, when inhaled, impart

prescribed doses over a given time.

RCTP 01-02 provides an equation for calculating an ACV (Eq. 5-12) using dose

conversion factors (DCFs):

0.05 (Sv )

 Bq 

ACV 

=

⋅

()

(Eq. 5-12)

 Sv  2,400 m 3

 m3 

DCF  

 Bq 

 

If the DCFo is used in place of DCF in Eq. 5-12, then this formula can be used to