Radiological Preparedness: A Short Primer

The devastating tsunami and subsequent meltdown of four reactors at Japan’s Fukushima Power Plant last year served as a reminder of the changing and expanding arena of emergency management in the field of radiological preparedness. The meltdown, the evacuation, and the public reaction that followed all provided real-world examples of some of the difficult issues and concerns that might well be encountered in a terrorist-based radiological event. However, most previous real-world disasters requiring terrorist-related emergency planning and response operations have involved explosives, chemicals, and biological agents, rather than radiological hazards.

Fortunately, the Fukushima meltdown had no terrorist involvement exacerbating the release of radioactive material. Even so, the incident drew widespread reaction – curiosity, concern, and response – from the public at large and visibly demonstrated that there is little knowledge of important radiological issues, including the response capabilities of the general population.

The incident itself, and subsequent release of dangerous radioactive materials, certainly raised levels of concern. However, it also provided a measured opportunity for response operations and for determining current weaknesses that should be studied to improve future event management capabilities not only in Japan but elsewhere.

The Initial Priorities: Education & Detection 

It has been obvious for some time that there is a compelling need for public education on radiation terminology and radiological dangers. In addition to explaining the details of nuclear plant operations and conditions during last year’s crisis, many news reports tried, without too much success, to: (a) define radiation in terms understandable to the non-expert; (b) fully and accurately describe the health hazards posed by radiation; and (c) explain the potential worst-case impact of radiation leaks (and/or incidents, whether deliberate or accidental).

The difficulty of addressing such a technically challenging topic became evident during the early stages of reaction and response operations. The close “relationship” between radiation itself and the source carrier materials was not discussed, and that important omission led to numerous problems in the public’s understanding of both contamination itself and of decontamination techniques. At least one televised Fukushima report showed the use of incorrect decontamination procedures, which further exacerbated the problem of understanding how people could become contaminated and exposed.

The dangers posed by radiological “debris” were also difficult to explain, leading many citizens to be understandably concerned about even extremely low levels of detection in the United States because there was no risk analysis to put the information into a proper context. For that and other reasons, there is now a demonstrable need to develop relatively simple and easy to understand guidelines – and provide the training materials needed therein – for educating the public. The development and use of such guidelines should clearly be carried out well before the onset of an actual radiological event.

Radiation: Detection and Dangers 

Another area of concern in any discussion of radiological preparedness involves the use of radiation detectors. There are four major types of ionizing radiation: alpha, beta, gamma, and neutron. Three of these – alpha, beta, and neutron – deal with the emission of subatomic particles from an atom; gamma radiation consists only of energy. Regardless of the type or form of radiation, human senses are not able to detect radiation on their own, so determining whether or not radiation is present requires the use of a radiation detector. Primarily for that reason, a response plan for any potential radiological event should include some form of radiation detection, along with information on the proper use of a detector to spell out, in significant detail, the actions required to deal with the presence of radiation if and when it is detected.

However, the immediate availability of a detector is not sufficient in itself. It is equally important that responders fully understand the functions and capabilities of the instrument to be able to cope effectively with the hazards being encountered. The best and most reliable detectors are specialized in nature – i.e., sensitive both to the type of radiation (alpha, beta, gamma, neutron) encountered and to the radiation energy being emitted.

In layman’s terms, this means that a device that detects gamma radiation, for example, may not necessarily detect neutrons as well and vice versa. Recognition of this limitation is critically important in responding to any radioactive release, particularly from unknown sources.

In general, gamma radiation detectors are both more rugged and more useful than other detectors because almost all types of radioactive materials give off at least some gamma radiation – even if the principal emissions are of another type. This operational characteristic allows a gamma detector to be a reasonably accurate key indicator, in virtually all event scenarios, of the presence or absence of radiation – even if there is some degree of uncertainty about either the total amount of radiation that might be present and/or the other (non-gamma) types of radiation in any given area.

The detectors also possess sensitivities that reflect the energy of the radiation. An instrument that can detect gamma within a specific energy range may not be useful, though, if the gamma energy of a source is lower or higher than the range capabilities of the detector used.

Protecting Both Responders & the General Public 

After the presence of radiation has been confirmed by a detector, the protection of responders and the local population immediately becomes the highest priority. It should be remembered, though, that the protection needed after a terrorist event is different in several ways from the protection required in an industrial or occupational setting. This distinction in priorities is due primarily to differences in duration of the exposure. For example, in a controlled occupational setting, the potential for contact and exposure might continue over a longer period of time. Alternatively, in an emergency-response situation, such as an attack or industrial accident, the immediate and most important goals are to remove people as quickly as possible from the scene and decontaminate them to shorten the duration of exposure.

In all radiation situations, another very important goal is to minimize the level of exposure as well as its duration, with a critical need to prevent the accumulation of radioactive material actually within the human body. The advantage of dealing with external radiation sources is that the person exposed can move away, or be taken away, from the radiation source and some, or all of it, can be washed off. This reduces exposure to the person.

Of much greater concern is an internal source of radiation, because removing material from inside the human body is almost impossible, particularly if there is more than just a minor amount of debris in a wound. The highest concern in the spectrum of internal radiation is respiratory protection, because the inhalation of radioactive material results in the permanent embedding of material within the inner recesses of the body, which increases long-term exposure of sensitive organs.

In preparing for any emergency or other dangerous event, the guidelines and other information provided should be set forth as clearly and simply as possible. Developing and disseminating easily understood descriptions of potential hazards, and the various protective procedures needed to cope with such hazards, is imperative. Those highest-priority guidelines may be even more critical in dealing with radiological issues, as was demonstrated at Fukushima, because of the more complex nature of the information provided. Applying the lessons learned from that disaster and from other incidents can help to mount more effective responses to similar events in the future.

Jeffrey Williams

Jeffrey Williams has served over the last 20 years as an environmental engineer in the U.S. Department of Defense. He also has served on two different emergency response teams, during which assignments he became an expert on radiological dispersal devices and various related topics. He has been a speaker at a number of public and private forums on topics ranging from environmental regulations to radiological preparedness. Prior to assuming his DoD post, he worked on the design and construction of hazardous-waste disposal sites for industrial facilities. He holds a Bachelor's degree in Nuclear Engineering and a Master's degree in Environmental Engineering from the University of Maryland as well as a Master's degree in Legal Studies from the University of Baltimore. He also has studied at the Massachusetts Institute of Technology’s Center for Advanced Engineering Studies.



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