4.0 DESIGN OF INDIVIDUAL MONITORING PROGRAMS FOR INTERNAL DOSIMETRY
In the context of internal dosimetry, individual monitoring includes routine bioassay (mentioned in
835.402(c)) and/or personal air sampling (not mentioned in 835.402(c)). The Implementation Guide on
Internal Dosimetry Programs provides general guidance for the design of a bioassay program, but little
guidance for air monitoring programs as a basis for internal dosimetry. In addition to considering all
points in the IDG, DOE sites should strive to comply with ANSI N13.39, "Design of Internal Dosimetry
Programs " (HPS 2000) when that standard is not in conflict with 10 CFR 835, the RadCon Standard, and
the IDG, as appropriate.
There are at least two conflicts between ANSI N13.39 and the IDG where the IDG should prevail.
The first is that the ANSI standard permits "censoring" of data in records, while the IDG forbids it. The
second is in the definition of investigation level (see Section 4.2).
There is a wealth of information on design of bioassay programs in the technical basis
documentation of many DOE sites (Sula et al. 1991; Hill and Strom 1993; Traub 1994; Baker et al. 1994;
Inkret and Miller 1995; Calvo and McLaughlin 1995; Fauth et al. 1996). The reader is advised to consult
this documentation for details of bioassay program design. Additional useful information on design can
be found in works by Skrable (Skrable 1992) and Carbaugh (Carbaugh 1994); in element-specific
standards (HPS 1996e; HPS 1994), in Regulatory Guides of the NRC (NRC 1992a, 1993a), in works of
the ICRP (ICRP 1988) and NCRP (NCRP 1985a), and in the Hanford Internal Dosimetry Project Manual
(Carbaugh et al. 1994).
Less information is available on design of personal air sampling programs as a basis for internal
dosimetry. Readers should consult the DOE's Air Monitoring Guide (DOE 1999d) and documents of the
NRC (NRC 1992a, 1992b, 1993a; Hickey et al. 1993). Guidance is given below on individual monitoring
for the short-lived progeny of radon and thoron. As used in this DOE Standard, personal air monitoring
refers to assigning specific air monitoring results to individual workers, regardless of whether the air
monitoring was accomplished by general area sampling, breathing zone sampling, or individual personal
(lapel) air samplers.
4.1 BIOASSAY COMPARED TO AND CONTRASTED WITH WORKPLACE AIR
DOE's occupational radiation protection system is dose-based. 10 CFR 835.209(b) is the only
requirement that addresses methods of internal dose assessment:
The estimation of internal dose shall be based on bioassay data rather than air concentration values
unless bioassay data are:
(2) inadequate; or
(3) internal dose estimates based on air concentration values are demonstrated to be as or more
10 CFR 835.209(b) does not require sites to use air monitoring data for internal dose assessment, but
permits sites to use air monitoring data under certain conditions. "Inadequate bioassay," for compliance
with 10 CFR 835.209(c), may be taken to pertain to radionuclides with effective half-lives too short to be
feasible for routine or special bioassay. Such radionuclides include radon and thoron and their short-lived