Routine Radiological Worker Dose Management

DOE-STD-1121-98

8.0 INTERNAL DOSE MANAGEMENT

10 CFR 835 requires internal dose evaluation programs for assessing intakes of radionuclides and

for maintaining adequate worker exposure records. The effective assessment of dose from intakes is

highly dependent on individuals (staff, management, radiation protection, medical, etc.) taking

appropriate action. 10 CFR 835 explicitly requires adding dose equivalent due to external irradiation to

committed effective dose equivalent due to irradiation by internal sources. Optimization principles

should be applied to maintain internal and external doses ALARA (ICRP 1978b, 1989a; DOE 1990c).

This necessitates a close working relationship and cooperation between staff, management, medical, and

radiation protection personnel. Each site should have a plan that documents the dose management

practices.

8.1 ROUTINE RADIOLOGICAL WORKER DOSE MANAGEMENT

Radiological workers should be requested to sign a statement concerning any prior work at a facility

where radioactive materials or radiation generating machines were used. The signed statement should be

available to the internal dosimetry group prior to a worker's being potentially exposed to radioactive

materials. The internal dosimetry group should determine the existence or potential existence of a prior

intake that provides current or future dose (e.g., exposure to short-lived radionuclides during the current

or past exposure year or exposure to long-lived radionuclides). Radiological workers who indicate the

existence or potential existence of an intake during previous work should be prevented from having

additional intakes until their cumulative TEDE, current retained quantities and current radionuclide

excretion rates (if any) have been established. This action should be accomplished either through receipt

of sufficient data from a previous employer(s) or by baseline bioassay measurements. If demands for the

worker's services are immediate and great, the worker's signed estimate of prior dose can be used until

official records are received.

8.1.1 Management of Dose from Previous Intakes (Work Restrictions)

In operation of programs for monitoring and controlling worker doses, consideration should be given

to the reduced effectiveness of bioassay monitoring for workers that have internally deposited

radionuclides (occupationally or medically derived). Special monitoring programs should be

implemented as necessary to ensure that protection of these workers can be provided.

8.1.2 Compliance with Internal Dose Monitoring Requirements

Management should require that radiation workers:

comply with facility contamination control requirements

participate in required bioassay measurements

inform the health physicists, other radiation protection personnel, or their immediate supervisor

as soon as an intake is suspected

Management should adopt additional administrative controls such as work restrictions for workers

who do not meet the above requirements.