Dose Limitation

DOE-STD-1121-98

8.2 DOSE LIMITATION

One acceptable method of limiting doses to workers involves the concept of administrative control

levels as described in the RadCon Standard (DOE 1999e). The establishment of such dose levels below

the limits provides reasonable assurance that limits will not be exceeded.

8.2.1 Interface and Coordination with the External Dosimetry Program and the

Radiological Control Organization

Since the DOE limits TEDE, a two-way communication system is needed between the internal and

external dosimetry programs. The two programs should develop a mechanism whereby the internal

dosimetry program receives, in a timely fashion, notification of external doses received by workers that

are a significant fraction of the applicable limits. Similarly, the external dosimetry program should be

informed, by the internal dosimetry program, of workers who have experienced significant intakes.

Together, the two programs must coordinate with the radiological control organization to prevent such

workers from exceeding administrative control levels and dose limits.

In addition, when planning radiological work, workers who may be likely to receive both external

irradiation and intakes of radioactive material should be identified by the radiological control

organization, and this information communicated to the internal and external programs so that checks can

be made of the dose status of workers for whom not all dose information is in the central records system.

For example, workers for whom an intake is suspected but not yet confirmed should be permitted to

engage in additional radiological work with significant potential for doses only if there is no indication

that additional work would put the worker in danger of exceeding an administrative control level.

8.2.2 Lifetime Dose Control

Lifetime dose control has been recommended by the EPA, the ICRP, and the NCRP, and described

in the RadCon Standard. However, lifetime dose control is not required by 10 CFR 835 in any explicit

way, and, in any case, is suggested only for radiological workers by the RadCon Standard and DOE

Technical Positions (DOE 1999e; Office of Worker Protection Programs and Hazards Management

1995b). Because of differing practices in the past, it is problematic to determine doses adequate for

today's dose quantities from historical bioassay and workplace monitoring data. Methods developed for

epidemiological studies, such as of Oak Ridge Associated Universities, may be of some help

(Crawford-Brown et al. 1989).

8.2.3 Doses due to Intakes Prior to January 1, 1989

Prior to January 1, 1989, regulations in the DOE did not require computation of HE,50 and HT,50

values from bioassay and workplace monitoring data. From January 1, 1989, sites were required to assess

and record these values. Prior to 1989, records of intakes, if they exist, were likely to be expressed in

fractions of a maximum permissible body burden (MPBB). There is no simple and straightforward

general method to convert MPBB values to HE,50 values. Sites should consider whether it is feasible and

cost-effective to attempt to historically reassess doses prior to 1989. The DOE position on prior years'

exposures records does not address doses due to intakes prior to 1989 or intakes at non-DOE facilities

(Office of Worker Protection Programs and Hazards Management 1995b).