Risk communication and radiological/nuclear terrorism: a strategic view

It is now widely recognized that effective communication is a crucial element in radiological/nuclear terrorism preparedness. Whereas in the past, communication and information issues were sometimes viewed as secondary in comparison with technical concerns, today the need to improve risk communication, public information, and emergency messaging is seen as a high priority. The process of improving radiological/nuclear terrorism risk communication can be conceptualized as occurring in four overlapping phases. The first phase involves the recognition that communication and information issues will be pivotal in shaping how a radiological/nuclear terrorism incident unfolds and in determining its outcome. This recognition has helped shape the second phase, in which various research initiatives have been undertaken to provide an empirical basis for improved communication. In the third and most recent phase, government agencies, professional organizations and others have worked to translate research findings into better messages and informational materials. Like the first and second phases, the third phase is still unfolding. The fourth phase in risk communication for radiological/nuclear terrorism-a mature phase-is only now just beginning. Central to this phase is a developing understanding that for radiological/nuclear terrorism risk communication to be fully effective, it must go beyond crafting better messages and materials (as essential as that may be). This emerging fourth phase seeks to anchor radiological/nuclear communication in a broader approach: one that actively engages and partners with the public. In this article, each of the four stages is discussed, and future directions for improving radiological/nuclear terrorism risk communication are explored.     

Lauriston S. Taylor Lecture: Radiation protection in the aftermath of a terrorist attack involving exposure to ionizing radiation

I would like to start this Twenty-Eighth Lauriston S. Taylor Lecture by expressing my gratitude to the National Council on Radiation Protection and Measurements (NCRP) for this unique occasion. I feel particularly honored for this opportunity to address a highly specialized and qualified audience of professionals who are specifically interested in what appears to be a forthcoming worldwide challenge, namely radiological terrorism and managing its potential radiological consequences.     

Managing the disposition of potentially radioactive scrap metal

In 2002, the National Council on Radiation Protection and Measurements (NCRP) issued Report No. 141, Managing Potentially Radioactive Scrap Metal. The report evaluates management policy and related issues regarding scrap metal generated in regulated facilities that have been under radiological control or have radiological concerns. It has been estimated that more than 9 million metric tons of scrap metal of all types that have been associated with the production or use of radioactive materials will be generated during the coming decades at various facilities across the United States. Currently, disposition of such metal has encountered particular obstacles, primarily because of the lack of a consistent disposition policy, systematic regulatory provisions, and, above all, public understanding. Without clarity in the regulatory passage, much of the scrap metal, including metal that has not been contaminated, could be mischaracterized as low-level radioactive waste, resulting in a costly disposition operation. NCRP Report No. 141 identifies this general category of metal as "potentially radioactive scrap metal" (PRSM) and discusses the viable disposition options for facilitating its management. Because much of the PRSM has been found to contain very low residual radioactivity or even none at all, one consideration is to release such metal outside of the radiological control framework. This would require the development and implementation of a set of strict release standards in the United States that would necessarily be risk-based and supported by a comprehensive management scheme. Developing a policy of this kind, however, would entail the resolution of many issues, not the least of which would be public acceptance, including that of the metal industry, of the possible recycling of PRSM in the general commerce.     

The 2000 NCRP Lauriston S. Taylor lecture--administered radioactivity: unde venimus quoque imus. National Council on Radiation Protection and Measurements

In this lecture, which celebrates Lauriston S. Taylor, a pioneer in radiation protection and founding president of the NCRP, I review some features of medically administered radioactivity through the past century and attempt to forecast some aspects of its future. I have used as my guide NCRP Report No. 70, Nuclear Medicine--Factors Influencing the Choice and Use of Radionuclides in Diagnosis and Therapy. The following topics are addressed: (1) decision-making considerations in the choice of radiopharmaceutical drug products, (2) factors in choosing an instrument for nuclear medicine procedures, (3) radiation dose, (4) evaluation of radionuclide procedures and their clinical utility, and (5) guidelines for performing nuclear medicine procedures.     

Panel session on "safety, health and the environment: implications of nuclear power growth"

This paper summarizes the presentations and the insights offered by panelists John P. Winston, Robert Bernero, and Stephen LaMontagne during the Panel on Safety, Health and the Environment: Implications of Nuclear Power Growth that took place during the NCRP 2009 Annual Meeting. The paper describes the opportunities and the challenges faced in the areas of infrastructure development, radiation control, licensing and regulatory issues, and non-proliferation as a consequence of the forecasted growth in nuclear power capacity worldwide.     

Comparison of the CT scatter fractions provided in NCRP Report No. 147 to scanner-specific scatter fractions and the consequences for calculated barrier thickness

The new NCRP Report No. 147 includes methodology to determine x-ray protective shielding for CT scanner rooms. This methodology assumes fixed values of the scatter fraction per centimeter (kappa) for the peripheral axis of the head and body CT phantoms. An investigation was performed to determine kappa for different makes and models of CT scanner and examine the consequences of the differences between these and the fixed NCRP values on a typical shielding calculation. kappa values were calculated using an equation for the scattered air kerma at 1 m from NCRP 147 (Kerma(scatter) = kappa x ScanLength x CTDI(100) x pitch(-1)) and using scattered air kerma data provided by the manufacturers and measured CTDI(100) (periphery) values. Typical barrier calculations, following NCRP 147 methodology, were performed for each CT scanner using the fixed kappa values and, separately, using the calculated scanner-specific values. Ten CT scanner models from three manufacturers were investigated. The calculated scanner-specific kappa values varied from the NCRP fixed values by as much as 82%. However, when these kappa values were used in typical barrier calculations, the final shielding requirements using the NCRP fixed values were 0.5 to 13% less than those using the scanner specific values. It is likely that such small underestimates in the shielding requirement due to using the NCRP fixed kappa values would be more than compensated by the conservative assumptions that are incorporated in a typical barrier calculation.     

A revised schema for performing diagnostic x-ray shielding calculations

This paper presents a method for performing diagnostic x-ray shielding calculations which is somewhat different than that given in NCRP Report No. 49. The method computes exposure at the location to be shielded from multiple sources of radiation in the room and accounts for differences in transmission characteristics of leakage and primary/scatter radiation. Also discussed in the paper is a method for determining shielding credit for existing common structural materials. Methods and results derived in the paper are then discussed and compared with NCRP Report No. 49.     

Warren K. Sinclair Keynote Address: Current challenges in countering radiological terrorism

Terrorism, although perhaps known by other names, is not a new phenomenon. It dates back to Roman times and perhaps even further in world history. Caleb Carr says terrorism "is simply the contemporary name given to, and the modern permutation of, warfare deliberately waged against civilians with the purpose of destroying their will to support either their leaders or policies... " In modern times, in the United States, there have been isolated violent acts of citizens against each other, although these acts often were directed toward symbols of the federal government. In the Middle East and other parts of the world, acts of violence against U.S. citizens and military personnel date back into the early 1960's. Some of these acts seem to be almost random in nature. But these events occurred in distant lands of sometimes uncertain locations to the American public, who soon forgot them and their important message. Even though there had been at least one other attempt on the World Trade Center, it was not until 11 September 2001 that successful, large-scale acts of terrorism came to our shores. In 1998, the National Council on Radiation Protection and Measurements (NCRP) formed a Scientific Committee and charged the committee with the task of providing a report on the state of preparation and the potential use by terrorists of radiation and radioactivity. The draft report of the Committee was produced a year in advance of the events of 11 September 2001 and was published in its final form about a month after these terrible events. The report brought together, in one place, information that existed in a number of areas, not all of which were easily accessible. However, there were a number of gaps in the information and in the planning and preparation for such events. These were reflected in a series of recommendations for organization, planning, and training, as well as for research and development in a number of areas. This brief presentation will address a few selected areas that remain a challenge for those preparing for terrorist events involving radioactive materials. More detailed discussions will be provided by the presentations at this NCRP Annual Meeting.     

Chemical, biological, radiological and nuclear terrorism: an introduction for occupational physicians

BACKGROUND: Chemical, biological, radiological and nuclear terrorism poses considerable threat throughout the world. AIM: To provide occupational physicians with an understanding of this threat and its main forms and what action can be taken to counter this threat. METHODS: Presenters at a conference on chemical, biological, radiological and nuclear terrorism were asked to contribute their evidence-based opinions in order to produce a review article. RESULTS: This paper presents a summary of the different forms of chemical, biological, radiological and nuclear terrorism and the effective counter-measures and also provides a review of current scientific literature. CONCLUSION: The threat of chemical, biological, radiological and nuclear terrorism is present throughout the world and is one that occupational physicians should be aware of, as well as the action that can be taken to counter it.     

Medical resources and requirements for responding to radiological terrorism

Medical planning and response to radiological terrorism is different than planning or responding to an event such as a nuclear power plant accident. The major differences are that now we must plan for multiple simultaneous events, suicide scenarios, and the possibility of biological, chemical, and radiological agents being used at the same time. This demands an "all-hazards" approach and not just a radiological response. An overview of the issues related to diagnosis, treatment, training, and resources is provided. Although the requirements for medical management are clear, the available resources have not been applied in a manner that results in adequate preparedness for radiological events.     

Dose limits for astronauts

Radiation exposures to individuals in space can greatly exceed natural radiation exposure on Earth and possibly normal occupational radiation exposures as well. Consequently, procedures limiting exposures would be necessary. Limitations were proposed by the Radiobiological Advisory Panel of the National Academy of Sciences/National Research Council in 1970. This panel recommended short-term limits to avoid deterministic effects and a single career limit (of 4 Sv) based on a doubling of the cancer risk in men aged 35 to 55. Later, when risk estimates for cancer had increased and were recognized to be age and sex dependent, the NCRP, in Report No. 98 in 1989, recommended a range of career limits based on age and sex from 1 to 4 Sv. NCRP is again in the process of revising recommendations for astronaut exposure, partly because risk estimates have increased further and partly to recognize trends in limiting radiation exposure occupationally on the ground. The result of these considerations is likely to be similar short-term limits for deterministic effects but modified career limits.     

放疗机房设计和防护检测中特殊问题的研究

目的 针对顶层薄弱的放疗机房,对机房周围的天空反射和侧向散射光子辐射进行计算和检测,探讨计算和检测中应注意的问题。方法 依据NCRP第151号报告中给出的计算方法及公式,对两个顶层薄弱的医用直线加速器机房周围天空反射和侧向散射光子辐射进行计算,并对机房周围地面和临近高层建筑的辐射水平进行检测,将计算结果和检测结果进行对比。结果 天空反射的计算结果和检测结果存在一定差异,侧向散射光子辐射计算结果与测量结果处于同一数量级水平。结论 对顶层薄弱的放疗机房,应考虑天空反射和侧向散射光子辐射,NCRP第151号报告中给出的天空反射理论计算公式存在局限性。     

Revised requirements for radiation emergency bioassay techniques for the public and first responders

This technical note reports the required sensitivities for bioassay techniques derived from a 0.1 Sv effective dose incurred in the first year following an emergency (recommended by ICRP) and those derived from a 0.25 Sv committed effective dose (recommended by NCRP) as dose thresholds for possible medical attention. During a large-scale radiological or nuclear emergency, the dose threshold chosen for medical attention may be raised, as available resources may be insufficient for conducting a sensitive contamination assessment and medical treatment of a large population exposed to radioactive contamination.     

Future role of the NCRP in radiation health protection

The predecessor organizations of the National Council on Radiation Protection and Measurements (NCRP) were established in 1929 (the U.S. Advisory Committee on X-Ray and Radium Protection) and in 1946 (the National Committee on Radiation Protection and Measurements). In 1964, the NCRP was formally chartered by the U.S. Congress as a national resource for scientific guidance on issues related to radiation measurements and health protection. In this paper the history and scientific contributions of NCRP are reviewed, followed by a discussion of its evolving mission and future scientific goals.     

A general solution to the shielding of medical x and gamma rays by the NCRP Report No. 49 methods

A general method for extending the principles and techniques of NCRP Report No. 49 of the National Council on Radiation Protection and Measurements has been developed. Equations are derived that determine the photon exposure through a radiation barrier taking into account the primary, scatter and leakage radiation from multiple radiation sources of various beam qualities. Applications of this include a general solution for medical radiation structural shielding and an analysis of commonly used diagnostic radiology shielding tables.     

Nuclear security and radiological preparedness for the olympic games, athens 2004: lessons learned for organizing major public events

In light of the exceptional circumstances that arose from hosting the Olympic Games in Athens in 2004 and from recent terrorist events internationally, Greece attributes the highest priority to security issues. According to its statutory role, the Greek Atomic Energy Commission is responsible for emergency preparedness and response in case of nuclear and radiological events, and advises the Government on the measures and interventions necessary to protect the public. In this context, the Commission participated in the Nuclear, Radiological, Biological, and Chemical Threat National Emergency Plan, specially developed for the Olympic Games, and coordinated by the Olympic Games Security Division. The objective of this paper is to share the experience gained during the organization of the Olympic Games and to present the nuclear security program implemented prior to, during, and beyond the Games, in order to prevent, detect, assess, and respond to the threat of nuclear terrorism. This program adopted a multi-area coverage of nuclear security, including physical protection of nuclear and radiological facilities, prevention of smuggling of radioactive materials through borders, prevention of dispersion of these materials into the Olympic venues, enhancement of emergency preparedness and response to radiological events, upgrading of the technical infrastructure, establishment of new procedures for assessing the threat and responding to radiological incidents, and training personnel belonging to several organizations involved in the National Emergency Response Plan. Finally, the close cooperation of Greek Authorities with the International Atomic Energy Agency and the U.S. Department of Energy, under the coordination of the Greek Atomic Energy Commission, is also discussed.     

International community efforts in prevention of nuclear terrorism

Terrorism is now a global threat, spreading its shadows over regions which were previously regarded as the exclusive domain of the military superpowers. One of the prime threats is nuclear terrorism, using nuclear or radiological agents. To assess the threat, it is important to include all factors that make it possible. A nuclear terrorist attack can be conducted in three basic ways, by detonation of a nuclear weapon, by sabotage or diversion of a nuclear facility or by dispersion of radioactive material into the environment (radiological weapon). Each possibility is specific and with different consequences. Nuclear terrorism can be prevented by establishing a global system which requires from all countries to strictly follow international rules of trading, storing and using nuclear and radioactive materials and to produce an efficient national legislation. The United Nations have provided a basis for such legislation in the form of the International Convention for the Suppression of Acts of Nuclear Terrorism.     

Fukushima nuclear incident: the challenges of risk communication

On March 11, 2011, a magnitude 9.0 earthquake occurred off the Sanriku coast of Japan, which resulted in multiple tsunamis. The earthquake and tsunami damaged several nuclear power stations, with the Fukushima Dai-ichi Nuclear Power Plant being the worst affected, which led Japan to declare a State of Nuclear Emergency. As of November 9, 2011, the National Police Agency of Japan reported a death toll of 15 836 people, with 3664 people still reported missing, following the earthquake and tsunami. Australian radiation health advisers were deployed to Tokyo early in the nuclear emergency to assist the Australian Embassy in assessing the radiological threat, to provide risk advice to Embassy staff and Australian citizens in Japan, and to plan for any further deterioration in the nuclear situation. This article explores the challenges of risk assessment, risk communication, and contingency planning for expatriate staff in the worst nuclear incident since Chernobyl, outlines what measures were successful in addressing heightened perceived risks, and identifies areas where further research is required, particularly in a radiological context.     

The ALARA principle in the context of a radiological or nuclear emergency

Traditionally, the concept of As Low As Reasonably Achievable (ALARA) has been applied to the workplace and to protect the public. The goals are to minimize small incremental exposures on a daily basis or per specific task, and on a yearly basis, thereby to keep the total annual dose equivalent as far below regulatory limits as practical. In an extreme emergency caused by radiological or nuclear terrorism, or a large scale radiological accident, it is proposed that the same principles can be applied to protect First Responders against potentially large exposures.     

Safety and security of radiation sources in the aftermath of 11 September 2001

The attack on the United States on 11 September 2001 resulted in an increased awareness of the need for safety and security measures to protect against terrorism. The potential use of radiation sources in terrorism, in particular radioactive sources, was recognized prior to 11 September 2001, but has taken on new significance since. The planning of security measures for radioactive sources must take greater account of the potential for deliberate acts to attack or use radioactive sources to expose people and cause contamination. The potential consequences of an act of terrorism using radioactive sources can be gauged from the consequences of serious accidents that have occurred involving radioactive sources. These include fatal and injurious radiation exposures, contamination of the environment, and serious economic and psychosocial costs the total effect of which is mass disruption. Steps are being taken to improve security for radioactive sources but strategic approaches that can minimize the threat of radiological terrorism should be considered. When justifying a practice that uses radioactive sources, the potential for diversion or use in terrorism should be considered to be a detriment. In this regard, the consideration and development of alternatives to radioactive sources, such as radiation producing machines, have been recommended by terrorism experts as measures to reduce the threat of radiological terrorism. If a practice using radioactive sources is determined to be justified, the need for special security measures to protect against terrorism should then become part of the safety assessment.