Health Physics Questions and Answers - Question 99

Question 99: The following questions concern the relationship of emergency plans for nuclear power plants to 10 CFR 20.1001 ("Purpose") and 10 CFR 20.1101 )"Radiation Protection Programs"). (a) To what extent do radiation protection programs need to be established such that during emergency conditions, the revised Part 20 can be complied with? (b) For example, in order to comply with the new EPA "Manual of Protective Actions For Nuclear Incidents" October 15, 1991, do germanium counting systems need to be established to analyze air samples for iodines and particulates, and computer programs to calculate CEDE, so that CEDE can be added to external dose to get TEDE? (c) Do emergency survey / plume chase teams need to wear breathing zone air samplers?

Answer: (a) In general, the revised Part 20 contains no new requirements that would make changes necessary in existing radiation protection programs as they relate to emergency conditions. 10 CFR 20.1001 includes the sentence, "However nothing in this part shall be construed as limiting actions that may be necessary to protect public health and safety," and the intent of this sentence is discussed in the statement of considerations (56 FR 23365, first column). NRC requirements concerning emergencies at NRC-licensed facilities (i.e., nuclear power plants and fuel-cycle licensees) are contained in 10 CFR Parts 30, 40, 50, and 70, and no conforming changes to these requirements were needed as a result of the revised Part 20. (b) and (c) See answer to (a). With regard to the offsite emergency workers such as fire fighters, law enforcement officers, civil defense workers and environmental field team members, the EPA manual provides guidance given in Table 2-2 titled "Guidance on Dose Limits for Workers Performing Emergency Services." In addition to the refinements in the dose limits, the revised EPA Manual uses the CEDE and the TEDE concept. There are no changes necessary with respect to the monitoring of the external exposure levels of these workers in the early phase of an accident except as noted in the referenced table. The question is, therefore, how to account for the inhalation dose of offsite emergency workers to prevent them from exceeding their limits. Due to the urgency of offsite response in the early phase of an accident, it will not be practical to set up air samplers at numerous locations and analyze those samples in a timely manner. Air samples and radiation measurements taken by the field monitoring teams will be valuable to determine the dose to emergency workers after the fact, but will be of little value during the actual performance of emergency tasks, since some form of real time exposure rate indication is needed. To create this real time indication, a correction factor can be developed that when multiplied by the emergency worker's dosimeter reading can provide a conservative estimate of the inhalation dose. The NRC and FEMA are currently investigating this issue. After appropriate review the NRC and FEMA will provide guidance for offsite agencies to use.

(References: 10 CFR 20.1001, 10 CFR 20.1101)