The World Needs to Reconsider the Safety of Nuclear Reactors

IRD: Since in the use of nuclear energy, safety is a very important factor and many safety measures are taken in this regard, can it be claimed that there is no danger in the use of nuclear energy?

AP: Although many studies on safety and facilities planning and simulation are carried out to know how to provide safety for the plant in normal and emergency situations, natural phenomena such as tsunamis and earthquakes may violate everything: the cooling system may stop working, and a disaster occurs. As the disaster may be very small or very big, natural disasters should be taken into account. The G factor (G stands for gravity, acceleration coefficient, and quakes that may occur) in Bushehr is very important. Is the Bushehr nuclear plant built in an appropriate place? Because when the Germans built the plant, they estimated the ratio as 0.5 G. It means that if an earthquake occurs, it approximately accelerates the earth by 0.5 G, but later they learned that it might be greater than this. As in Japan, the earthquake showed us that the prophecies are always true.

IRD: What exactly happened in the nuclear plants in Japan?

AP: A plant has a cooling circuit playing an essential role in the first cycle. The first cycle emits thermal energy produced inside to be used in producing electricity. The amount of produced energy is very considerable in this cycle. For example, in Bushehr it is the three thousand megawatts. In the Japanese nuclear plant, it is almost the same or less. If the transfer of energy is delayed for just one second, three thousand megawatts of energy is stored and when the first circuit is broken and the path is closed, or the water is taken out of the network, the temperature is kept in place until a restart. Perhaps much heat is collected in the reactor, causing a meltdown, which is extremely dangerous. In this case the water gets decomposed and nitrogen is produced—the first explosion will occur due to the accumulation of hydrogen.

IRD: What effect does meltdown have on humans?

AP: Of course, meltdown is not complete yet, but if it occurs and uranium permeates, it will be very complicated. Because radioactive materials, especially those gaseous or emitted into the air by vapor, may cover the land. Of course this depends on the wind direction. This is very dangerous, and can damage human life in long run.

IRD: Did the Chernobyl incident occur in this manner?

AP: Chernobyl was a different situation. The Chernobyl incident occurred due to operator fault and a failure to observe safety tips. The reactor of the Chernobyl nuclear plant was carbonic, containing graphite. Graphite caught fire and the disaster occurred. But the plants in Japan have a retainer or containment, a concrete compact building. The Chernobyl plant did not have any containment and the explosion caused the roof of the building to be destroyed and radioactive materials to escape into the atmosphere as gas. But in this case, this will not happen because the concrete building will keep the materials confined. The incident at the Three Mile Island plant in the U.S. in the 70’s was perhaps worse than that of Chernobyl, but due to the maintenance building, radioactive materials were containment.

IRD: How are safety factors are observed in the Bushehr power plant?

AP: The Bushehr power plant project was designed by Germans and continued by Russians. The probability that such a thing could happen in the Bushehr reactor is low. The problem is not the incident, because we do not know what the next accident will be. The direction and intensity of the wind and many other factors affect the issue. No tsunami threatens the Bushehr plant, but no one can predict what will happen if an eight-Richter or greater earthquake occurs. We witness that in some areas, volcanos have not erupted for many years, and these things are very difficult to predict. I cannot predict anything about the Bushehr nuclear plant, but in general, serious measures should be taken related to the safety of reactors worldwide, which will number more than one thousand in the next 50 years.

IRD: A final question: as a person familiar with the concepts, how urgent is a reconsideration of the safety of reactors?

AP: I think that we cannot omit energy production from our life. An overall international system among all countries can be established first, to save energy. Second, as we cannot stop consuming fossil fuels, due to environmental issues like the increase in unstable weather and lacking any other energy source, we are obliged to have nuclear reactors. The best way is to form an international association for all countries, especially for those that desire nuclear plants, and all plants, whether in Bushehr or Japan, should be under a strong international technical committee, because any incidents will involve the whole world. 

However, the IAEA currently monitors but it is limited to laws and regulations and recommendations, and is not in an executive role. Plants located anywhere in the world should observe some standards including those of personnel training, facilities, etc., and sanctions must not include components required in plants. Impartial considerations should always be made to keep plants in a normal and safe condition. For example, we are obliged to use Russian technology at Bushehr, and if one day we need replacements for the German parts used in initial build of the plant, they will not be sold to us du to the sanctions imposed on Iran. This is unacceptable to us, and in light of the Japan disaster, should be unacceptable to the world.