Cleanup & Mitigation Work Group
Restoration of contaminated areas and equipment to safe condition
The detonation of a radiological dispersal device (RDD) or a nuclear weapon will distribute radioactive materials over a wide area. Depending upon the type of radioactive materials, the area of dispersal, the intensity of deposition, the response of the population to the event, and a number of other factors, it may become necessary to encourage residents to remain in their homes or places of business for several hours or days ("shelter in place") or to evacuate an affected area. Various types of actions may be taken to quickly remove more troublesome deposits of radioactive materials ("decontamination"). These actions are taken to quickly reduce the potential for exposures to radiation and radioactivity ("mitigation").
People living in an are with higher than normal levels of radioactivity will receive higher than usual radiation doses. Low doses of radiation are generally not harmful. High doses can be harmful. The potential for harm can be estimated and related to the amount of radioactivity that is present in an affected area. Thus, by limiting access to an affected area based upon the concentration of deposited radioactivity, one can control the dose to people. Limiting this dose then reduces the chances of any potential harm to an exposed person.
Cleanup techniques vary from the very simple (soap and water) to the very complex (robotic systems that can access highly contaminated areas and buildings). Although a technique is simple, it can be very effective in reducing radiation exposures; the more complex techniques are generally reserved for specialized work in very radioactive areas. Good housekeeping and personal hygiene is a very effective countermeasure to harm from the radioactivity of an RDD or nuclear weapon.
"How clean is clean" is an issue that requires much discussion. It is very simple to model the behavior of radioactivity in the environment, and it is very simple to calculate the amount of radiation dose that one would receive from such an exposure. These approaches, although useful, are highly speculative and very dependent upon the initial assumptions regarding the effects of radiation and the behavior of radioactivity. Speculative assertions regarding these effects must be validated by reference to scientific studies and other sources of reliable information. The establishment of limits for these situations must balance the potential for radiation effects against the (not insignificant) costs (personal, social, and economic) of an inappropriate application.
The Cleanup & Mitigation Work Group members are:
Individual members of the Society have suggested these websites as useful references for additional information on the subject of mitigation and cleanup of terrorist attack areas:
Environmental Protection Agency presentation on the upcoming Liberty RadEx Exercise to be conducted the week of April 26, 2010. The Exercise is sponsored by EPA, Pennsylvania Department of Environmental Protection, and City of Philadelphia Office of Emergency Management. This will be the first full-scale exercise dedicated to the post-emergency response to a radiological dispersion devise (RDD). NEW!
From the Health Protection Agency: UK Recovery Handbook for Radiation Incidents
The Emergency Operations Training Academy (EOTA) is recognized as the model technical training provider for DOE emergency operations personnel, while expanding its customer base to include other designated government and private-sector national and international organizations that require professional training, education, and vocational services. In this expanded role, the Academy is a vital training asset for DOE and the nation. Quality training is available on many topics pertinent to all aspects incident response, from planning to clean-up. Courses are available in several configurations, web-based training (WBT), videotape, CD-ROM, and classroom. The site offers links to State emergency management websites and a link to the Emergency Management Network. Once you register, you can access the resources section that contains many useful documents, from the FRMAC Manual, to the Homeland Security Act, to the Atomic Energy Act, and much more.
Guidance regarding safe limits of radioactivity and radiation in the environment following a nuclear accident or terrorist event ("protective action guides" or PAGS) are described in EPA 400-R92-001, Manual of Protective Action Guides and Protective Actions for Nuclear Incidents. [This manual is currently being reviewed and updated.] Additional information regarding emergency mitigation and cleanup are available at the website of the US Environmental Protection Agency (USEPA).
The Health Physics Society has published a position paper regarding acceptable levels of radioactivity following a terrorist attack. See Guidance for Protective Actions Following a Radiological Terrorist Event and Background Information on "Guidance for Protective Actions Following a Radiological Terrorist Event."
If limits for residual radioactivity are too high, there is a risk that, over time, people would become ill from excessive radiation exposure. If the limits are too low, the cost of performing a cleanup to an area may be so prohibitive that no cleanup could be performed as it would be too expensive. In these situations, people would lose their homes and places of business due to the limits. In the case of terrorist attack, these losses are generally not insured, thus economic disruption brought about by inappropriately low limits could actually be more stressful and damaging to health than the potential harm presented by the radiation exposure itself. These factors are balanced in determining limits through a process known as "risk assessment." See What is Risk Assessment for a discussion of the issues and links to EPA web-based radiological risk and dose calculators. NEW!
Establishing Remediation Levels in Response to a Radiological Dispersal Event (or "Dirty Bomb") summarizes a journal article in the May 1, 2004, issue of Environmental Science and Technology by EurekAlert, of the American Association for the Advancement of Science, "New Efforts Needed to Address Cleanup After 'Dirty Bomb' Attack."
The IAEA document "Remediation of Sites with Mixed Contamination of Radioactive and Other Hazardous Substances" Technical Reports Series No. 442 has a lot of good basic information on how mixed waste may be handled.
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