Design of Individual Monitoring Programs for Internal Dosimetry

DOE-STD-1121-98

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

MONITORING

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:

(1) unavailable;

(2) inadequate; or

(3) internal dose estimates based on air concentration values are demonstrated to be as or more

accurate.

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