epr-method (2003) - IAEA Publications - International Atomic Energy ...

A7 - ASSESSING THE INITIAL PHASE Threat category Responsibility
Elements I II III IV V O L N
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Those responsible for assessments and management should be aware that dose projections are very
uncertain and that for severe emergencies making accurate projections of off-site doses may be
impossible. They should expect differences in results from models run by different organizations and
should not use these projections as the sole basis for protective actions.
Arrange for monitoring and sampling by teams consistent with Appendix 15, response in times consistent
with Appendix 10 and a strategy consistent with Refs. [18] and [27].
Provide precalculated default OILs for assessing environmental data following a release, and techniques
to revise OILs according to the actual radionuclide mix of the release consistent with Ref. [18]. Preclude
frequent changes to OILs in order to maintain confidence and stability in the decision making process.
Plans should identify responsibilities for deciding whether or not to revise OILs and the criteria to be
used to decide on whether a change is required.
Arrange to conduct monitoring of people within the emergency zones to determine if decontamination or
medical follow-up is warranted. Include criteria for initiation of decontamination and medical follow-up.
The criteria should be tied to potential health effects (e.g. doses approaching deterministic effect
thresholds) and be consistent with other criteria (e.g. criteria for relocation). For facilities such as
nuclear power plants with the potential for large radioiodine releases, establish a means of measuring
thyroid radioiodine intake (e.g. by direct gamma measurement next to the thyroid).
Arrange to analyse the environmental monitoring data and produce information useful for decision
making (e.g. maps). Ensure that the results of different monitoring organizations are comparable,
including those in other States. As soon as possible, all organizations (facility, local, national, and
international) conducting environmental monitoring and analysis should consolidate their efforts and
form a single organization co-located at a radiation monitoring and assessment centre- RMAC (see
Appendix 14).
The assessment staff should be aware of the great uncertainties in assessment early in an emergency and
the need to make best estimate assessments, and of the problems that can arise from inappropriate
pessimistic assumptions.