Evaluation of Repurposing Archetypal Preventive Radiological/Nuclear Detectors for the Consequence Management Mission.

In the first hours or days after an unplanned release of radioactive material to the environment, the radiation detection instruments most widely available to local first responders may be those currently fielded for interdiction missions. This study investigated how such preventative radiological/nuclear detection instruments could perform if repurposed for consequence management missions. A representative sample of three archetypes (body-worn, human-carried, and other/large-detection-volume equipment) encompassed six categories: personal radiation detector, extended-range personal radiation detector, personal emergency radiation detector, radioisotope identification device, human-portable detector/backpack, and vehicle-mounted large-detection-volume detector. Overall 19 models of equipment were included in the study. Laboratory evaluations were designed to assess the capabilities of the instruments in four consequence management missions: exposure rate, integrated exposure, radiation survey, and contamination screening. As applicable, the evaluations included measurement of exposure rate, integrated exposure, overrange response, and angular response. The results were compared to benchmarks from the American National Standards Institute N42.49A. The performance of the instruments for initial screening for contamination was assessed by an automated radioactive source moving past the detectors at various speeds and distances. The results demonstrate that if the equipment is used in accordance with the mission analysis and categories and within the original equipment manufacturer specifications, it is possible to achieve sufficient accuracy to estimate and document doses to responders, plan entries into contaminated areas, detect contamination, and protect the public until such time as outside resources arrive with sufficient numbers of standard health physics instruments and personnel dosimetry to replace the preventative radiological/nuclear detection instruments. This evaluation campaign was conducted to complement the National Council on Radiation Protection and Measurements Report 179, Guidance for Emergency Response Dosimetry.

External dosimetry in the aftermath of a radiological terrorist event.

This paper reviews external dosimetry in emergency preparedness planning for a potential terrorist release of radioactive material in a densely populated area. The radiation dose received by response workers and members of the public is needed to understand health risks. The existing framework for dosimetry of routinely occupationally exposed workers is not directly applicable to all emergency workers who would respond to a radiological terrorist event. Emergency preparedness plans incorporate various old and new dosimetry technologies, including quartz fibre electrets, electronic dosemeters, personnel badges and wallet cards. Environmental monitoring and dose calculations are the usual methods for determining public dose. However, during the late-phase response, after removable contamination has been eliminated, it may be easier and more straightforward to provide individual dosimetry for members of the public who may be moving through a city with varying contamination areas. Doing so could allow resumption of normal activities earlier and promote confidence in reusing the site.

Establishing remediation levels in response to a radiological dispersal event (or "dirty bomb").

The detonation of a radiological dispersal device (RDD) could produce significant social and economic damage, the extent of which would depend largely on how quickly and effectively cleanup levels were established and on public acceptance of those levels. This paper shows that current radiological cleanup laws and regulations, models for converting dose or risk goals to cleanup concentrations, and existing site-specific criteria were not designed specifically for RDD cleanups but, absent changes, would apply by default. The goals and approaches of these legal and methodological structures often conflict; using them in response to terrorism could undermine public confidence, cause delays, and produce unnecessary costs or unacceptable cleanups. RDD cleanups would involve immediate priorities not envisioned in the existing radiological cleanup framework, such as balancing radiation risks with the health, economic, and other societal impacts associated with access to the infrastructure necessary to sustain society (e.g., hospitals, bridges, utilities). To minimize the achievement of terrorism goals, the elements of an RDD cleanup response--including updating existing legal/regulatory structures to clarify federal authority, goals, and methods for developing RDD cleanup criteria--must be in place soon; given the complexity of the issues and the potential societal impact, this effort should be expedited.

A new tool for analysis of cleanup criteria decisions.

Radionuclides and other hazardous materials resulting from processes used in nuclear weapons production contaminate soil, groundwater, and buildings around the United States. Cleanup criteria for environmental contaminants are agreed on prior to remediation and underpin the scope and legacy of the cleanup process. Analysis of cleanup criteria can be relevant for future agreements and may also provide insight into a complex decision making process where science and policy issues converge. An Internet accessible database has been established to summarize cleanup criteria and related factors involved in U.S. Department of Energy remediation decisions. This paper reports on a new user interface for the database that is designed to integrate related information into graphic displays and tables with interactive features that allow exploratory data analysis of cleanup criteria. Analysis of 137Cs in surface soil is presented as an example.