Currently, nuclear power plays a quite visible role in the world electricity generation (∼11%). However, before the Fukushima Nuclear Power Plant (NPP) severe accident in March of 2011, NPPs generated about 14% of the world’s electricity. Accounting that after, mainly, Chernobyl NPP severe accident a number of power reactors built and put into operation in the world decreased from 120 within 1985–1990 to about 22 per 5 years (within 1995–2015), we might face a significant shortage of operating power reactors within 2030–2040. Therefore, it is important to evaluate current status of nuclear-power industry and to make projections on near (5–10 years) and far away (10–25 years and beyond) future trends in nuclear-power industry. In the current paper statistics on all current nuclear-power reactors were analyzed and based on that future trends were estimated in terms of types of reactors to be left after 10 years, new types of reactors to be put into operation, projections of how many reactors and of which types will be build. To make any projections an average operating term of power reactors should be estimated. In the current paper a nuclear-power-reactor operating term of 45 years was considered. Also, rates of building and putting into operation power reactors worldwide were estimated, and several scenarios of future developments in nuclear-power industry in the world and in selected countries were considered.

Through experience feedback of the Chernobyl and Fukushima nuclear accidents, source term determination including release rates and release curves, becomes a key issue in nuclear accident impact assessment. When faced with monitoring device failure, use of off-site monitoring data and atmospheric dispersion model simulation results to inverse the source term has been proven an effective means in many case studies. In this paper, we have developed a powerful source term inverse system based on constrained least squares algorithm approach and Gaussian atmospheric diffusion model, and we carried out 15 SF 6 field trace experiments at a coastal nuclear power plant site in China from August 22, 2007 to August 31,2007, to validate the source term inversion model. From the 15 simulation results, the 5th,8th and 9th inverse results are the best, and the relative error of inverse source term and true source term is between 10.12% and 16.42%, this is mainly because these three experiments are the most successful, and effective sample points of three experiments are above 25, its distribution is also uniform. It is shown that accuracy, number and distribution of the on-site monitoring will directly affect the inversion source term results. In general, results of source term inversion model are close to the field experiment, within the same magnitude, which shows that constrained least squares algorithm method and Gaussian atmospheric diffusion model can be applied in nuclear accident source term determination. Results of this study show that constrained least squares method is simple and highly efficient and has a high application value.

The design of a nuclear reactor containment building is of key importance in order to enhance the safety of a nuclear power plant. Owing to nuclear accidents such as TMI, Chernobyl and Fukushima, more and more attention is paid to the passive concept in nuclear power development. In order to improve the safety of new generation nuclear power plant, passive systems are widely used, passive containment cooling system in AP1000 is one of the typical example of such kinds of systems. It’s function is to transfer the heat produced in the containment to the atmosphere and keep the pressure in the vessel below the threshold under such accidents as Loss of coolant (LOCA), main steam line break (MSLB), etc. The system operates based on natural circulations inside the steel vessel and in the air baffle outside the containment, and the cooling water is sprayed to the steel surface to enhance the heat transfer process. A proper model simulating the system behavior is needed for system design and safety analysis, and a multivolume lumped parameter approach is employed in order to analyze the containment integrity and to study the long term response of postulated Loss of coolant (LOCA) accidents and Main steam line break (MSLB) accidents. However, the temperature and pressure distributions cannot be described detailed by such model, which is important to study the T-H characteristics in the containment. In this paper LOCA has been simulated on MATLAB using a given pipe break size and the response of containment is analyzed. Furthermore, the results are compared with the results in the Westinghouse Design Control Document 2002. Then the thermal hydraulic performance is studied, the factors such as the air temperature, containment pressure and mass flow rate of the coolant and their effects on the containment are analyzed. This research is done to get further insight on the safety analysis of reactor containment regarding maximum temperature and stress calculation inside the containment.

Fukushima Daiichi NPP accident would be terminated, if sufficient accident countermeasures, such as water proof door, mobile power, etc [1, 2]. In case of Europe, it had already installed the heat removal system and filtered containment venting system (FCVS) from the lessons of TMI and Chernobyl Accidents. The new regulatory standard in Japan, the filtered vent system (FCVS) should be installed, and prevent the radioactive material in case of the severe accident and the overpressure breakage prevention of a primary containment vessel (PCV) and also the robustization of the FCVS. The authors examined the severe accident process in the 2 nd unit of Fukushima Daiichi NPS, and found the vent by FCVS should be done before water injection into the core. The PCV spray and water injection into the pedestal basement should be also the countermeasures to the severe accident. Countermeasures for an intentional aircraft collision should be installed too. Upon occurrence of a severe accident (SA), vent gas with radioactive fission products is blown out to a scrubbing pool through numerous venturi nozzles. Mist in steam moves upward to a metal fiber filter through a multi-hole baffle plate. After the mist is removed by that filter, radioactive methyl iodine (CH 3 I) is captured on the surface of a molecular sieve or AgX, made from zeolite particles with silver coating. A FCVS visualized test facility was installed at Hokkaido University. An AgX filter is used down-stream of the scrubbing pool and metal fiver filter. Thickness of AgX filter is very important parameter to obtain enough decontamination factor (DF). The DF for the radioactive iodine exceeds 10,000 at bed depth (AgX filter thickness) greater than 75mm.

The history of building and operating nuclear power plants (NPPs) in Germany dates back to the late 1950s and will come to an end in 2022. By then all NPPs still in operation will have to shut down in a defined sequence, according to the revisions made to the German Atomic Energy Act as a consequence of the accident at the Fukushima Dai-Ichi NPP. Nine out of 17 NPPs have already been shut down permanently as a consequence. Due to the progress in science and technology, the design of the electrical power supply of German NPPs got more complex and hardened against various scenarios with time. The latest generation of NPPs built in Germany in the late 1980’s — the pressurized water reactor of type Konvoi — was designed with Defence in Depth in mind. They are connected to several voltage levels of the power grid and feature two layers of AC emergency power systems, each of which fulfills the n+2 redundancy criteria. The second of those layers is especially hardened against the influence of certain internal and external events and is part of an emergency control system which can keep the plant in a safe state autonomously for 10 hours under certain conditions. With this being the state of science and technology at that time in Germany, most of the older NPPs in operation had been retrofitted by 2011 with systems that were designed to partially compensate for these plants’ weaker original design. Various events such as the accident at the Chernobyl 4 NPP in 1986 and also the accident at the Fukushima Dai-Ichi NPP in 2011 led to changes in the German regulatory framework and recommendations to the NPPs for further retrofitting activities. In the regime of electrical power supply, the latest changes in requirements and corresponding retrofitting of the NPPs in operation include mobile diesel generators with corresponding, redundant feeding points, an enhanced coping capability for station blackouts with only DC-power left and measures to ensure bringing back AC-power within the available time. In this presentation the author gives an overview over the historic development of the electric design in German NPPs and discuss details of the most recently added requirements on retrofitting — e.g. in the new regulatory framework — to enhance the robustness of the electrical power supply of those NPPs. An update on the progress on the actual retrofitting process of the German NPPs with respect to these new requirements is given.

At the beginning of the French nuclear history, CEA controlled all the nuclear development including its safety. In 1950s, this situation was changed by the participation of many industrial companies, which means industrialization of nuclear technology. This change became clearer when they adopted PWR in 1970. And so they needed and established a system to make safety regulation by putting the multiple actors’ opinions together. After the accident of Chernobyl, antinuclear public opinion has increased. And in 1997, The Greens obtained the post of the Minister of Ecology. These facts required more independent and transparent regulatory system, so in 1998, a report which proposed to establish a new regulatory organization was published. On the basis of this report, they founded ASN in 2006. From this French history, we can say that as the relationship between nuclear technology and the society changed, the regulatory body also changed to meet the necessity.

Although the water radiolysis, decomposition of water by radiation, is a well-known phenomenon the exact mechanism is not well characterized especially for severe accidents. The author first reviewed the water radiolysis phenomena in LWRs during normal operation to severe accidents (e.g., TMI- and Chernobyl accidents) and performed a scoping estimation of the amount of radiological hydrogen generation, accumulation and release for the Fukushima Daiichi accident. The estimation incorporates the decay heat curve after a reactor trip combined with G-values. As much as 450 cubic meters-STP of accumulated hydrogen gas is estimated to be located inside the PCV just prior to the hydrogen explosion which occurred a day after the reactor trip in Unit 1. When a set of radiological chain reactions are incorporated the resultant reverse reactions substantially reduce the hydrogen generation, even when removal of molecular products (i.e., oxygen and hydrogen) is assumed stripped rapidly from boiling water through bubbles. Even in the most favorable configuration a typical amount of hydrogen gas reduces to only several tens of cubic meters. Finally, the author tested a new mechanism, “radiation-induced electrolysis,” which had been applied to his corrosion studies for last several years. His theory has been verified with the published in-pile test data, although he has never tried to apply this to his severe accident study. The predicted results indicated that the total inventory of hydrogen gas inside RPV may reach as much as 1000 cubic meters in just 3 hours during the SBO due to a high decay heat soon after the reactor trip through this process.

The Chernobyl accident and Fukushima 1 Nuclear Power Plant accident are the most serious accidents in the history of the nuclear technology and industry. A large amount of radioactive materials from nuclear power plant were released, leading to huge damage and long-term effect on the environment as well as the human health neighbor to the plant. Therefore, simulating the transport and transformation of radionuclides in the atmosphere is significant for decision makers to take steps at all level. Now, many different dispersion models are widely applied and used to simulate the transport and transformation of radionuclide such as Gaussian model, Lagrangian model and Eulerian model. Though the Eulerian or Lagrangian models have several advantages, such as high spatial resolution, fully 3D descriptions of the meteorological, the simple Gaussian plume model is still widely chosen because of its higher accuracy and faster calculation. In this study, the atmospheric dispersion of leaked radioactive material during nuclear accident is simulated by using Gaussian plume model. The relative concentration distribution of the radionuclides and the trajectory of the distribution centrode are obtained in taking account of different geographical environments, wind direction, wind velocity, and stability category. These results can provide a favorable evidence for the management of nuclear accident emergency.

The most painful lessons that engineers will learn from reviews of the Fukushima disaster relates to the unacknowledged failure of regulators, designers and utilities in better retrofitting existing reactors in a timely manner to better withstand and mitigate known severe accident related challenges to reactor and containment integrity. Commercial nuclear power reactors have operated for over 50 years, and the first severe accident progression studies and understanding of related phenomena began to mature over 30 years ago. However, some very basic accident prevention, mitigation and management measures have not been required by the regulators and hence not initiated by the utilities. In public reviews that inevitably followed, severe accidents in power reactors at Three Mile Island, Chernobyl and Fukushima have been often presented as site specific aberrations in design, operations, safety culture and acts of God beyond mortal imagination. If a sincere soul searching, regulatory overhaul and actual, effective, timely and far reaching measures are not taken for operating reactors, the world is bound to witness recurring severe core damage scenarios followed by series of studies that will predictably conclude that such severe accidents can happen only in other jurisdictions and in other designs and that ‘our’ reactors are ‘safe’ and only minor enhancements are required to placate the anxious public or inquiring regulators. The paper examines the role played by regulators and other Canadian stakeholders in failure to ensure that the so-called residual risk from operating nuclear reactors is minimized in a timely manner. It presents specific examples of known deficiencies in PHWR designs that may degrade a sustained loss of power from a recoverable outcome into significantly more severe consequences. It discusses ideas for potential design retrofits and reiterates the need for more open, concerted and cooperative efforts internationally in accident progression and consequence analyses and supporting experiments. Taking station blackout as example of an instigator of a severe accident, the paper discusses certain elements of the current PHWR designs that accelerate the onset and progression of core damage and present substantially degraded opportunities for mitigation and control. It demonstrates how in many cases, a sustained loss of power in a PHWR may cause a containment bypass with early and unacceptable off-site consequences. Many issues discussed in this paper are common to other reactor designs and regulatory jurisdictions.

The analysis of the radioactive aerosol scavenging by rain after the Chernobyl accident highlights some differences between the modelling studies and the environmental measurements. Part of this gap is due to the uncertainties on the scavenging efficiency of aerosol particles by raindrops, in particular for drops with a diameter larger than one millimeter. The IRSN (Institut de Radioprotection et de Sûreté Nucléaire) has decided to launch an experimental study to measure with a better accuracy the scavenging efficiency of large raindrops. The scavenging efficiency of aerosol has been determined by measuring precisely the mass of aerosol particles collected by a single drop after its path through an atmosphere loaded with particles. The collection efficiencies for drop diameters of 2 mm and 2.6 mm (previously unknown for atmospheric aerosols) are measured. The impact of these new data on modeling of the washout of the atmosphere by the rain is noticed.

The accidents of Chernobyl and Fukushima have shown the necessity to better understand all the mechanisms implied in the scavenging of aerosol particles released to the atmosphere during a nuclear accident. Among all the phenomena involved in the deposition of aerosol particles, we focus here on the aerosol particles scavenging by the raindrops below the clouds, also called washout (as opposed to the rainout, which concerns scavenging inside the clouds). The strategy of IRSN to enhance the knowledge and the modelling of any mechanism involved in the washout of aerosol particles by rain spans from environmental studies, to analytical ones. The semi-analytical approach chosen here is halfway between these two modes of reasoning. A companion paper is also submitted to the conference to present the microphysical approach chosen at IRSN. In order to perform this study, aerosol particles were dispersed in the TOSQAN chamber, which is a large cylindrical enclosure (4.8 m height with 1.5 m internal diameter). The aerosol particles once dispersed, synthetic rains of different kinds (from stratiform to convective rains) can be activated. Finally, the instantaneous spectral scavenging coefficients are determined from the spectral decrease of aerosol particles concentration in the chamber as a function of time. In order to be able to produce synthetic rains representative of any tropospheric events, a special generator has been designed; it is based on a vibro-rotative disk. This generator is able to produce monodispersed rains at the top of the TOSQAN chamber with rainfall rates from 7 to 15 mm/h and drops diameters from 0.5 to 2.5 mm injected at velocities close to their terminal one. During these tests, the spectral aerosol concentration is measured in line with the help of a Welas granulometer. This instrument is based on white light scattering. The results of these experiments highlight the influence of “meteorological” conditions inside the chamber on the washout of the chamber atmosphere, especially when the relative humidity is reaching saturation.

Hydrogen accumulation at the top of the containment or reactor building may occur due to an interaction of molten corium and water followed by a severe accident of a nuclear reactor (TMI, Chernobyl, Fukushima Dai-ichi). Hydrogen accumulates usually in a containment of nuclear reactor as a stratified semi-confined layer of hydrogen-air mixture. Detonation of such mixture may lead to significant damage of the containment structure. A series of large scale experiments on hydrogen combustion and detonation in a semi-confined layer of uniform and non-uniform hydrogen-air mixtures in presence of obstructions or without them was performed at the Karlsruhe Institute of Technology (KIT). Critical conditions for deflagration-to-detonation transition and then for steady state detonation propagation were experimentally evaluated in a flat semi-confined layer. The experiments were performed in a horizontal semi-confined layer with dimensions of 9×3×0.6 m with/without obstacles opened from below. The hydrogen concentration in the mixtures with air was varied in the range of 0–34 vol.% without or with a gradient of 0–1.1 mol. %H 2 /cm. Effects of hydrogen concentration gradient, thickness of the layer, geometry of the obstructions, average and maximum hydrogen concentration on critical conditions for detonation onset and then propagation were investigated with respect to the safety analysis. Blast wave strength and mechanical response of the safety volume was experimentally measured as well.

The necessity of safety analysis methods and probable scenarios of accidents teaching in the education of experts for nuclear industry in Ukraine has been realised only after the Chernobyl accident. We developed the content of the first educational course in probabilistic safety analysis in 1995 based on the experience of the countries having developed nuclear power, the USA first of all, and on the training course of the Idaho National Laboratory. After this in 1996 the new course in probabilistic safety analysis of nuclear power plant (NPP) was adopted at our university. The new educational course in safety for students was developed and adopted in 2009 educational year - “Safety culture at nuclear installations of Ukraine”. Education and training in safety culture in higher educational institutions and in the nuclear power plants is a part of the general modern process of maintenance of safety, it is recommended by IAEA standards. The principles of safety culture are taken as a basis of the modern concept of safety of nuclear power plants. This work has received a positive appreciation from the management of departments of safety and training of the personnel of operating organization National Nuclear Energy Generating Company Energoatom (NNEGC Energoatom) and from other leaders of nuclear industry. The content of this educational course was discussed at the international scientific conferences on safety culture in 2008 and 2010, and was preliminary printed in the professional journal «Nuclear and radiation safety». The purposes of education have been defined as a survey, generalizing course on safety of the NPP with an allocation of safety issues on the foreground. Practical questions of the equipment and NPP systems work, their interaction in emergencies and the role of the human-operator are studied. The procedure of failure analysis at NPP is studied. Students analyze equipment work, root and direct causes of incidents. Methods of estimation of safety conditions based on observable operational indicators are studied. Parameters, variables and indicators of safety culture are studied. As a result of gained experience we have come to the conclusion about high advisability of educational courses in safety for students. Specially formed knowledge and education in the field of safety from a student’s bench are the basis of safety culture of the future nuclear industry expert.

In the entire history of commercial nuclear power so far, only two major accidents leading to damage of reactor core have taken place. One is Three Mile Island (TMT) accident (1979), which is caused by a series of human error, and the other is Chernobyl accident (1986), which is due to the combined reason of design defects and human errors. After TMI and Chernobyl accidents, in order to reduce manpower in operation and maintenance and influence of human errors on reactor safety, consideration is given to utilization of passive safety systems. According to the IAEA definition, passive safety systems are based on natural forces, such as convection and gravity, and stored energy, making safety functions less dependent on active systems and operators’ action. Recently, the technology of passive safety has been adopted in many reactor designs, such as AP1000, developed by Westinghouse and EP1000 developed by European vendor, and so on. AP1000 as the first so-called Generation III+ has received the final design approval from US NRC in September 2004, and now being under construction in Sanmen, China. In this paper, the major passive safety systems of AP1000, including passive safety injection system, automatic depressurization system passive residual heat removal system and passive containment cooling system, are described and their responses to a break loss-of-coolant accident (LOCA) are given. Just due to these passive systems’ adoption, the nuclear plant can be able to require no operator action and offsite or onsite AC power sources for at least 72h when one accident occurs, and the core melt and large release frequencies are significantly below the requirement of operating plants and the NRC safety goals.

Until around 1990 Japanese nuclear power generation maintained the world’s top-level safety and high capacity factors. However, repeated accidents and troubles in the latest decade (including those experienced earlier and newly uncovered) caused the capacity factors decline, and simply the regulatory authorities reinforce their rules. Nevertheless, Japan has maintained its nuclear technologies and knowledge by continued constructions of new nuclear power plants (NPP) and the technology and knowledge were handed down and accumulated., while the construction decreased drastically worldwide after the Chernobyl accident in 1986. It should be meaningful to see how Nuclear Knowledge Management (NKM) worked over this period. All 17 nuclear power stations in Japan were visited from January to September 2007 for field survey of maintenance practices, human resources development programs and quality assurance activities. From the analyses of the collected information, the strengths and weaknesses in nuclear knowledge management have been induced. The lessons we concluded are elaborated in the following subjects. • Pluses (+) and minuses (-) of multi-layered structures of nuclear industry: its correlation with NKM (accumulation, preservation and creation of technologies and knowledge); • Technology improvement and knowledge accumulation in the new quality assurance systems; • “Olds” and “News” in transferring technologies and knowledge, and in developing human resources; • Rebuilding of on the job training (OJT) and off the job training (Off - JT): its contents of lessons and training; • Appropriate use of the manuals: to know its usefulness and limits; • Appropriate deployment of the inspection enforcement: incentives and formalities; • Motivation of active information sharing by the adequate intellectual property management; • Lateral development of best practices, and new value creation by the shared knowledge. The Japanese electric utilities and nuclear industry should further advance their information sharing of valuable experiences such as troubles and good practices, and strengthen their self-management. Thus, they will be able to contribute, with their advanced strengths of accumulated/preserved nuclear technologies and knowledge, to meeting the growing needs of new NPP construction worldwide in the Nuclear Renaissance. NKM will in turn be further advanced on the so-called spiral-up track.

Former studies assumed that, after fission process occurs, the highly ionized new born atoms (20–22 positive charge), ionize the media in which they pass through before becoming stable atoms in a manner similar to 4-MeV-particles. Via ordinary chemical reactions with the surroundings, each stable atom has a probability to form chemical compound. Since there are about 35 different elemental atoms created through fission processes, a large number of chemical species were suggested to be formed. But, these suggested chemical species were not found in the environment after actual releases of FP during accidents like TMI (USA, 1979), and Chernobyl (former USSR, 1986), also the models based on these suggested reactions and species could not interpret the behavior of these actual species. It is assumed here that the ionization states of the new born atoms and the long term high temperature were not dealt with in an appropriate way and they were the reasons of former models failure. Our new approach of DEEP ATOMIC BINDING (DAB) based on the following: 1. The new born atoms which are highly ionized, 10–12 electrons associated with each nucleus, having a large probability to create bonds between them to form molecules. These bonds are at the L, or M shells, and we call it DAB. 2. The molecules stay in the reactor at high temperatures for long periods, so they undergo many stages of composition and decomposition to form giant molecules. By applying DAB approach, field data from Chernobyl, TMI and nuclear detonations could be interpreted with a wide coincidence resulted.

The term ‘ultimate risk’ is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the event of a hypothetical and severe accident situation. The author would like to point out that current source terms which are based on the information from the Windscale accident (1957) through TID-14844 are very outdated and do not incorporate lessons learned from either the Three Miles Island (TMI, 1979) nor Chernobyl accident (1986), two of the most severe accidents ever experienced. As a result of the observations of benign radionuclides released at TMI, the technical community in the US felt that a more realistic evaluation of severe reactor accident source terms was necessary. In this background, the “source term research project” was organized in 1984 to respond to these challenges. Unfortunately, soon after the time of the final report from this project was released, the Chernobyl accident occurred. Due to the enormous consequences induced by then accident, the one time optimistic perspectives in establishing a more realistic source term were completely shattered. The Chernobyl accident, with its human death toll and dispersion of a large part of the fission fragments inventories into the environment, created a significant degradation in the public’s acceptance of nuclear energy throughout the world. In spite of this, nuclear communities have been prudent in responding to the public’s anxiety towards the ultimate safety of nuclear plants, since there still remained many unknown points revolving around the mechanism of the Chernobyl accident. In order to resolve some of these mysteries, the author has performed a scoping study of the dispersion and deposition mechanisms of fuel particles and fission fragments during the initial phase of the Chernobyl accident. Through this study, it is now possible to generally reconstruct the radiological consequences by using a dispersion calculation technique, combined with the meteorological data at the time of the accident and land contamination densities of 137 Cs measured and reported around the Chernobyl area. Although it is challenging to incorporate lessons learned from the Chernobyl accident into the source term issues, the author has already developed an example of safety goals by incorporating the radiological consequences of the accident. The example provides safety goals by specifying source term releases in a graded approach in combination with probabilities, i.e. risks. The author believes that the future source term specification should be directly linked with safety goals.

Between May 28 – June 4, 2005, under the organization of the Hungarian Nuclear Society (HNS) and the Hungarian Young Generation Network (HYGN) — which operates within the framework of the HNS — a scientific expedition visited the Chernobyl Nuclear Power Plant and the surrounding exclusion zone. The participants were young Hungarian nuclear professionals supervised by more experienced experts. The main scientific goals of the expedition were the followings: • Get personal experiences in a direct way about the current status of the Chernobyl Power Plant and its surroundings, the contamination of the environment and about the doses. • Gather information about the state of the shut down power plant and the shelter built above the damaged 4th unit. • Training of young nuclear experts by performing on site measurements. The Hungarian expedition successfully achieved its objectives by performing wide-range of environmental and dosimetric measurements and collecting numerous biological and soil samples. Within the 30-km exclusion zone the influence of the accident occurred 20 years ago still could be measured clearly; however the level of the radioactivity is manageable in most places. The dosimetrical measurements showed that no considerable exposure occurred among the members of the expedition. The analysis of samples has been started at the International Chernobyl Center in Slavutich. During the expedition not only environmental sampling and in-situ measurements were carried out but it was also well documented with photos and video recordings for educational, training and PR purposes. A documentary TV film was recorded during the expedition. The first-hand knowledge acquired during the expedition helps the authentic communication of the accident and its present-day consequences, which is especially important in 2006, 20 years after the Chernobyl accident. Since Ukraine and Hungary are neighbor countries the media constantly discuss the accident, the consequences and the risks of using nuclear energy. In addition in November 2005 Hungary’s parliament approved plans to extend the lifetime of the country’s four-unit nuclear power plant. In order to have the crucial public support for nuclear energy it is very important to dispel unrealistic dismay and misbelieves regarding these questions. Thus it is extremely beneficial to have a film on this topic created by nuclear professionals especially for the public audience. In 2005 a book on the Chernobyl accident was published in Hungary that covers this expedition in a full chapter [2]. We plan to present the film to the audience of the conference.

According to models used to predict health effects of fission products enter the human body, a large number of fatalities, malignancies, thyroid cancer, born (genetic) defects, ...etc.. But the actual data after Chernobyl and TMI accidents, and nuclear detonations in USA and Marshal Islands, were not consistent with these models. According to DAB, these data could be interpreted, and conflicts between former models predictions and actual field data explained.

A large number of studies and models were established to explain the fission products (FP) behavior within terrestrial and water ecosystems, but a number of behaviors were non understandable, which always attributed to unknown reasons. According to DAB hypothesis, almost all fission products behaviors in terrestrial and water ecosystems could be interpreted in a wide coincidence. The gab between former models predictions, and field behavior of fission products after accidents like Chernobyl have been explained. DAB represents a tool to reduce radiophobia as well as radiation protection expenses.