HPS - ANSI/HPS N13.3
Dosimetry for Criticality Accidents
|Publication Date:||1 January 2013|
This standard is applicable to operations for which there is a potential for a criticality accident involving personnel exposure. This standard provides guidance and requirements using the quantity absorbed dose. The units of absorbed dose are given in SI units of gray (Gy), with the traditional units of rad following in parenthesis. The assessment of quantities other than absorbed dose will not be addressed as these can be determined after a criticality accident by careful spectral analysis and application of conversion coefficients specified by the appropriate regulatory requirements. It should also be noted that the absorbed dose concept is applicable for an acute dose that potentially results in an immediate nonstochastic effect. Therefore, the quantity absorbed dose is used instead of dose equivalent or other dosimetric quantities. The range of personnel absorbed dose covered by this standard is approximately 0.1 to 10 Gy (10 to 1,000 rad).
This standard provides requirements and performance criteria for implementation and maintenance of a dosimetry system capable of providing personnel absorbed doses in the event of a criticality accident. Such an accident is characterized by the release of large amounts of penetrating prompt radiation. The dosimetry system may include: physical detectors such as activation foils and photon dosimeters (e.g., thermoluminescent dosimeters [TLDs], ion chambers, optically stimulated dosimeters, etc.); biological samples such as blood sodium or live cells for cytogenetics; and analysis capabilities based on models, known geometry effects, and information based on eyewitness reports. The resulting individual absorbed dose estimates are intended to:
(1) Aid in prioritizing medical attention for affected personnel appropriate to their level of absorbed dose.
(2) Provide information useful for correlating absorbed doses with biological responses.
(3) Provide information appropriate for reporting to regulatory agencies and for release to the public.
(4) Provide information which, when combined with additional analysis, will result in data useful in deriving information for integrated lifetime exposure records.
In cases where dosimetry services are provided by an outside organization or vendor, it is the responsibility of the procuring organization to ensure criteria in this document are met.