Nuclear Safety Impossible Even With Advanced Reactors

The Nuclear Power Corporation of India and Atomic Energy officials are taking a anti national stand by propagating that the large sized advanced nuclear plants with passive nuclear safety reactors are absolutely safe. In fact they are propagating that the Kudankulam nuclear plant is indeed one of the safest nuclear plants built in the world. The reactor contains multiple overlapping safety features including passive safety systems like passive heat removal systems, hydrogen recombines and core catchers which make it a unique Engineering feat which can withstand the most stressful condition and avoid catastrophic events like the Fukushima reactor explosions. The above false claims being made by the officials of the Atomic Energy establishment for the proposed multiple unit reactors at Kudankulam, Jaitapur, Kovvada and Bhavnagar may one day cause Fukushima type accidents due to several causes including Bombing by terrorists] [] and missile attacks, sabotage, meteor-hits, electrical, mechanical and human failures. Russian Reactors are known to be prone to accidents of different grades [ ] and the VVER reactors from Russia are likely to have similar accident –prone components in the Kudankulam Reactors Even most of the existing nuclear plants in India are CANDU reactors using high pressure heavy water are located in Tamilnadu, Gujarat and Rajasthan and these reactors have already proved that they are not at all safe reactors to ensure public health and welfare and their pollution levels in the environment are highly under-estimated by the Indian Nuclear Authorities and the same may be verified by browsing through the following websites to find out the true emissions from similar reactors in other countries abroad: here and here.

Thus the claims of Indian Atomic Energy experts on safety of existing reactors are unbelievable.


The Government authorities are violating the regulations under the Environmental Protection Act and also the Atomic Energy regulation Acts in preparing the relevant reports on nuclear safety, nuclear plant explosion scenarios, risk analysis, Emergency Response Plans including disaster management. Even while considering nuclear reactor safety problems they are ignoring the potential pathways for causation of small accidents, medium accidents and large scale accidents which may lead to large scale explosions that cause national economic losses estimated at Rs.5 lakh crores and such failures may make the Indian states and the nation to become not only economically bankrupt but also convert the healthy and prosperous land into nuclear burial ground. In order to avoid this man-made disaster the millions of Indian people must understand how even the advanced nuclear reactors may fail in the long run.


It must be understood that passive nuclear safety is merely a safety feature of a nuclear reactor that does not depend upon operator actions or electronic feed back to shut it down safely in case of an accident usually caused by overheating consequent to a loss of coolant accident. These modern reactors rely on engineered components so that the anticipated behavior according to laws of physics will be slow rather than accelerate the nuclear reaction in those circumstances. But in the case of older reactor designs the natural tendency for the reaction is to get accelerated rapidly due to increased temperatures so that either operator triggered intervention or electronic feedback was needed to prevent damage to the reactor. In considering the safety aspects of an advanced reactor the words “Passively Safe Reactor” is to be considered more as a description of the methods and strategy employed to maintain a degree of safety rather than it is a description of the level of safety as clarified in the following examples.

Whether a passive safety reactor is really safe or dangerous depends upon the criteria used to evaluate the safety level. Advanced designs use both active and passive safety systems to make them more safer than older designs. Reactor manufacturers brand them as “Passively safe” but this term causes confusion as compared with “inherently safe reactors” in the public view. Actually there are no “Passive safe rectors or passively safe systems but only passively safe components of safety systems exist. Such safety systems are employed to control the reactor when it goes outside normal working conditions due to anticipated operational small scale failure occurrences or accidents while the control systems are used to operate the reactor under the normal working conditions. A system sometimes combines both features. Passive safety refers to various components of the safety system whereas inherent safety refers to control system processes irrespective of the presence or absence of safety specific subsystems. In an advanced reactor the passively safe reactors are the concrete walls and the steel liner while active systems operate by use of components like valves for prompt closure of the piping leading outside the containment, feed back of the reactor status to the external instrumentation and control systems both of which need external power to function.

The degree of passive safety of components are classified into 4 categories namely, A,B,C and D depending upon what the system does not make use of the parameters;

1. No moving working fluid, 2. No moving mechanical part

3. No signal inputs of intelligence, 4. No external power plant

Under Category A (1+2+3+4) falls the fuel cladding that uses none of these four parameters and the fuel cladding is always closed and maintains the fuel and fission products inside and is not open before it reaches the reprocessing plant.

Under category B (2+3+4) comes the surge line that connects the hot leg with the pressurizer and helps to control the pressure in the primary loop of a pressurized water reactor and it uses a moving working fluid to fulfill its mission.

Under category C (3+4) comes the accumulator which does not require signal output of intelligence or external power. When the pressure in the primary circuit drops below the set of point of the spring loaded accumulator valves, the valves open and the water is injected into the primary circuit by compressed nitrogen.

Under category D (4 only) comes the scram which uses moving working fluids, moving mechanical parts and the signal inputs of intelligence but not the external power or forces. The control rods drop by being driven by gravity once they have been released from the magnetic clamp.

Unfortunately nuclear safety engineering is never that simple. Even when the rod is thus released it may not fulfill its function because it may get stuck up due to earthquake conditions or due to deformed core structure. This clearly shows that though it is a passively safe system and has been properly actuated it may not fulfill its mission and nuclear engineers have considered this aspect. Infact only a fraction of the rods dropped are enough to shut down the reactor. Passive safety components are seen in almost all nuclear power plants like the containment, hydro-accumulators in the pressurized water reactors or pressure suppression systems in boiling water reactors. The important issue is that no pumps are required to fulfill the function of a safety system and all the active components like valves and other components of the systems work with electric power from the batteries.

Passive safety is not synonymous with reliability or availability and even less with assured adequacy of safety features although several factors potentially adverse to anticipated performance can be more easily counter acted through passive design as per public perception. But active designs using variable controls do permit much more precise fulfillment of safety functions and this may be particularly useful under accident management conditions. Many water cooled and moderated reactors when scramed cannot remove residual production and decay heat without either process heat transfer or the active cooling system. In other words while the inherently safe heat transfer process provides a passive safety component and prevents excess heat in operational mode “ON” the same process does not provide a passive safe component in operational mode “OFF SCRAM”. The accident at Three Mile Island nuclear plant exposed this design deficiency. The reactor and steam generator were “OFF” but with loss of coolant it still suffered a partial melt down. In the case of Kudankulam reactors although passive core cooling system provides some extra additional degree of safety components it has still a minor flaw of possible rusting related to containment structure liner. When the dome rusts through the shell and if it remains unattended for sometime in the highly corrosive coastal atmosphere at Kudankulam there is a definite possibility of expulsion of poisonous radioactive pollutants into the atmosphere. These new technologies do not take it into full consideration their design basis for handling the Tsunami type scenarios as underestimated in the case of Fukushima where multiple safety systems failed simultaneously. Similar failures occurred in Bhopal industrial plant disaster. Reactors with a few centimeters thick iron shell first and many inches thick concrete shell on top of it can perhaps withstand the impact of only light airplane crashes or other moving objects but cannot withstand serious missile attacks or meteorite crashes, particularly when the reactor contains several soft pockets in and around the nuclear containment shell. Infact about 15 to 25 pipeline penetrations in the containment shell allow process fluids to move from containment to turbine building and back. Further more penetrations for compressed air system, instrumentation and control systems and power supply cable connections are provided and the designers must analyse the risk problems associated with the failure of these penetration plants. During the pipe rupture analysis certain assumptions that breakages will occur in these penetrations are made. The reactors are located at lower level in the containment shell and if the containment is exposed to tsunami waves these penetrations may fail due to the impact of debris and other floating materials and consequently the containment gets flooded and the failure of critical components and systems become inevitable.


The western countries like United states and Germany do not believe that nuclear power is safe. The proof is provided by a few illustrations. In Germany the Chancellor Ms.Angela Merkel discussed nuclear safety with the experts in the aftermath of the Fukushima nuclear reactor explosion and concluded that nuclear safety is a myth and hence decided to phase out nuclear power plants in Germany. Germans are taking steps to provide energy to the people by means of alternative sources like wind, solar power, hydro-power and other fossil fuels which are safer and cheaper. Infact the people in the United States and the nuclear power industry itself does not believe in the safety and economy of the nuclear power. Consequently after Three Mile Island accident US has not promoted nuclear power for 3 decades . That American contractors do not believe in nuclear safety is proved by the enactment of the Price-Anderson Nuclear industries indemnity Act of 1957 which was expected to expire in 1967 but was recently extended to be in operation upto 2025. This Act was passed in USA because no private Insurance company was willing to come forward to grant insurance policy for nuclear plants to cover the true costs of the risks of nuclear reactor accidents. If the American nuclear power industrialists plan to convince the public that nuclear power is absolutely safe they must actively campaign to repeal the Price-Anderson Act and express their willingness to pay the real costs of compensation to the victims of the accident caused by the risky behavior of the plant. It was originally expected that within 10 years from 1957 the reactor manufacturers would be able to overcome all the problems connected with nuclear safety and thereby demonstrate the insurance companies about the safety of the reactors and purchase the required private insurance policies at market rate without depending upon any Government subsidies or interventions to protect the hazardous nuclear industry at the cost of the public health welfare and national economy.


The concept of absolute safety of a nuclear reactor verges on the idealistic level while the achievement of a relatively safer reactor will always be possible. Any system process or product is only as safe as our current knowledge of how to test for safety is balanced against our need to make it economically viable, ecologically sound and socially useful and acceptable.

Even destructive testing is limited to “known unknowns” because one cannot test for what one has not anticipated. There will be always “unknown unknowns” to challenge the state of art in safety design and engineering. For instance in the case of reactors nobody is going to design a reactor to withstand even the remote chances of a direct hit by a large meteorite or a freak powerful lightening strike that disables all electronics or an aerial bombing directly over the reactor that is powerful enough to rip most of the structures of a nuclear plant.

The question on safety of reactors is not whether the present designs are safer and if so to what degree because any measures taken will only just reduce the risk but do not eliminate it. The actual danger with the nuclear reactors is not the likelihood of an accident but the potentially catastrophic consequences of the problem and thus truly safe reactor can never be achieved. Even if the reactor failure occurs once in 1000 years for a Fukushima like accident it is still far too high because affected area due to radioactive contamination becomes uninhabitable in case of plutonium contamination for the next 2.5 lakh years. Unlike most other forms of disaster like a dam collapse, a fire accident or an aeroplane crash there is no second chance after nuclear accident.

No technology can be made 100% safe and accidents happen at anytime and anywhere. Nothing can never be truly safe and the risks associated with nuclear plant failure can be reduced and mitigated. Moreover the risks associated with nuclear waste disposal will last for such a long time extending over decades and centuries that any other alternative energy sources must be used even if they are costly. No sane people living in present society have the right to take such a risk in order to protect future generations because the Indian constitution provides guarantee to the right to life and the right to livelihood as well.

If the experts of the Nuclear Power Corporation of India and the Atomic Energy Commission, the Union Cabinet and the members of Parliament and state legislature honestly believe that nuclear plants are absolutely safe let them agitate for cancellation of the Civil Liability for Nuclear Damage Act 2010 and prove to be millions of Indians that they are truly known as patriotic in serving the cause of the nation as Mahatma Gandhi and other leaders who laid their lives in fighting for securing the freedom of India from the tyrannical rule of the imperialistic Britishers for ushering in a true welfare state that uphold the traditional Indian slogan “SARVE JANA SUKHINO BHAVANTHU”

Prof.T.Shivaji Rao,
Director, Center for Environemntal Studies,
GITAM University, Visakhapatnam-530045
Phone: 0891-2504902
Mobile: 9949319038
Mobile of Personal Assistant: 9885324013
for Biodata: contributor/Shivaji.rao (website on Inexpensive cloud seeding by farmers)





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