Nuclear chimney

On the safe design of nuclear reactors and the nuclear chimneys.

Dmitrii Kouznetsov.

The design of the nuclear plants is considered. The role of the decay heat is discussed. The basic concept of а safe nuclear reactor is suggested.

Introduction

The most of nuclear reactors are built not only above the sea level, but also above the ground level. In the case of an accident, the wide area is exposed to the neutrons (giving the secondary radiation), all the buildings of the plant (even those that are not directly connected to the radioactive materials and the turbines) are exposed also to the gamma-radiation. If a problem with a cooling system, even after to release the pressure, the coolant (usually, water) should be delivered to the high altitude of the reactor; this requires the pump and, at the failure, implies the human sacrifices. As an alternative, the reactor becomes a nuclear chimney that evaporates into the atmosphere its nuclear fuel, together with the coolant and the sand delivered by the suicide "liquidators" as it took place in Chernobyl; the decay heat is more than sufficient for this, even if the chain reaction is successfully stopped.

Past century, the Nobel laureate Andrei Sakharov has expressed his opinion about the nuclear reactors above the ground: such reactors are dangerous and should be prohibited by the international law .

The Chernobyl disaster happened not only due to the criminal government of the soviet veterans in the USSR, but also due to the wrong, dangerous concept of the architecture of the reactors of 20th century. Such reactors are unsafe, as unsafe were the steam vehicles of century 19.

The reactor built up above the level of ground is designed to melt and to evaporate into the stratosphere the most of its nuclear fuel at any disfunction of the cooling system; only the continuous forced delivery the coolant (and the good will of the operators) prevent the nuclear reactors from the automatic conversion to the nuclear chimneys.

At the present level of technology, the human civilization cannot maintain the culture without the energy of the nuclear fission. Yet, the quantum technologies are far from realization of the quantum processes that would allow the use of the unclear energy without the chain reaction, without the nuclear pots. Therefore, it is difficut to insist on the total closure of the nuclear industry. But the citizen and scientists and the governments should insist on the safe design and the safe operation of the nuclear reactors.

About the specialists

Some of the specialists, who work in the nuclear industry, have deep knowledge in this area; much deeper than that of the researchers who work on other problems. But the nuclear specialists are involved; so they cannot be considered as independent experts, therefore, the people and the governments should consider all their reports very critically. The explosions of the nuclear reactors at Chernobyl and Fukushima should be considered as illustrations to this general statement. For this reason, being no nuclear specialist, I dare to share with the colleagues my opinion about the development of the world-wide nuclear industry.

The control from the side of neutral non-specialists is essential. In the USSR, the development of the nuclear industry was covered by the KGB; these mafiosi had carefully excluded any possibility of the control from the side of the society. As the result, the slavery was used to force the nuclear workers to perform deadly–dangerous job; the absence of any ecological control leaded to the nuclear contamination of the significant part of the USSR: even after the extensive and successful exploration of the new (still not contaminated) lands (called "tselina" or "целина" ), the USSR, having huge territories, had to import large amounts of grain and other food form the USA, Canada and Europe . Even the huge reserve of territory does not save the society from the uncontrolled activity of the nuclear companies.

The control from the side of non-specialists is especially important for Japan. Having no reserves of territories (as Russia still has), the only few nuclear chimneys of the Chernobyl style could convert the Japan islands to the place unusable for life, industry, research. The safe design of the reactors and the appropriate laws to provide the realization are necessary condition for the survival and prosperity of Japan.

Good luck and "avos"

The hope for some "good luck" has the Russian national equivalent "avos" ("авось"). The Chernobyl is a strong illustration of the results of such an "avos". The "avos" has deep reasons and benefits for the designers of the reactors, the manufacturers and the owners; it is not the only the Russian specifics.

If someone or some company own some under-safe reactor, then, in the most of cases (say, 90%), nothing happens with namely this reactor. Then the benefits can be considered as income of the administrators. They look innocent.

If the reactor undergoes some serious catastrophe, the expenses cannot be covered by the owners, and they look innocent; they tried to do their best, but the unfortunate coincidence of bad circumstances happened: poorly trained operator happened to be on duty just at the moment of the earthquake, and (just by the unfortunate coincidence), the power electric line and the roads happened to be damaged just after the earthquake, and (again, the third coincidence), the strong earthquake was followed by a big tsunami, and so on.. However, the workers of the plant had demonstrated the exceptional heroism, and only due to their self-sacrifices, the reactors did not become the nuclear chimney.

The law should explicitly exclude such justifications. Any "avos" in the nuclear industry should be considered as crime and reported and punished (preferably, before the disasters, but late is better than never).

Only underground reactors

The minimization of the construction expenses seems to be the main reason against the underground reactors. The legislation should be adjusted: in addition to the prohibition, the above–ground radioactive objects (for example, the nuclear waste storage, or the recycling factories) should be subjects of high taxes.

The core of reactor should be placed deeply under ground, below the level of see or the nearby lake. The cover should protect the building for the case of tsunami of amplitude that correspond to the centuries–age marks "do not build any homes below this point".

Each reactor should be equipped with the passive emergency cooling system. The vessel of the reactor should be connected to the emergency cooling water reservoir large enough to absorb all the decay heat by the passive convection. In the safe case, the vaporized cooling water should be condensed below the emergency reservoir, excluding the release of the radioactive vapor into the atmosphere. And even in the worst case (total destruction of all the mechanisms of the nuclear plant), the merged into water reactor cannot delver the nuclear fuel to the stratosphere.

The filling of the containment vessel with water should be performed automatically at the failure of the conventional cooling system. Such a design should imply no labor of any suicide workers nor firefighters. At the radiation emergency, the personal should be able just to leave the plant without to worry that it converts to a Chernobyl–like nuclear chimney. Such a chimney should be excluded by the construction of the reactor, not by the heroic efforts of the liquidators-kamikaze.

The storage of the used active rods in the open pools should be also prohibited. The spent fuel that cannot be recycled immediately should be stored in underground caves filled with water. The utilization of the small amount of vapor produced by the residual heat should be prescribed by Law, whenever it is economically justified or not.

The modern reactors shut-down at the strong earthquakes. The advantage of such automatic shut–down is not obvious. The shutting down of the nuclear reactor is long–term and complicated and dangerous procedure. Perhaps, it should not begin at the strong earthquake. The underground reactors should be designed for the normal operation even while the Richter-10 earthquake, followed by a tsunami that reaches the ancient memorial rocks that mark the edges the tsunami–floodings happened centuries ago. (Perhaps, even some correction could be made for the centurial raise of the level of the oceans.)

The reactors above the ground and nuclear waste storages above the ground should be prohibited by the Law. (In the similar way, in the century 20, the tests of the nuclear weapon in the atmosphere were prohibited). The underground reactor should be designed in such a way, that it cannot be concerted into a nuclear chimney neither by the earthquake, not by tsunami, nor by an error of the operator, not by a hit of an enemy missile. Such a resistance is key of the safety of Japan.

Not panacea

The total prohibition of the reactors placed above the ground should be followed by the updates in the Law.

Roboting

According to the news, no robots could help the humans in cooling of the reactor during the Fukushima disaster. (some attempts to use robots for measurement of the radioactivity were reported, but their role does not look very high.) 25 years ago, the same happened at Chernobyl: robots were not able to work long in the condition of high radiation; so, the soviet veterans used to send soldiers, devastating the demographic resources of the country. The robots are still too expensive; they cannot be used in the regime "for use once only" and the human workers are sent instead.

The civilized way to stimulate the development of robots would be the law, that specifies that the minimum insurance for the nuclear workers should be still higher than the price of the radiation–resistant robot than could perform the same operation (wether such a robot is already manufactured or not yet). Such payments would force the nuclear companies to develop the cheap and efficient robots.

More about insurance policy

The underground placement of the reactors is not a panacea. It is necessary, but not sufficient condition for the safe operation. The prohibition of the above-ground reactors should be accompanied by the modernization of the legislation and, in particular, the insurance policy.

The hiding of information about the contamination levels at the spreading of the dangerous ionizing radiation should be considered as serious crime, similar to the murderer: the consequences (deaths) are similar.

The total compensation of the material losses (harvest, cattle, homes, business, etc.) should be realized by the insurance companies in a short time (say, within a week) since the refugees get the indication to escape. Such indication may be official warning, or just luck of the up-to-date information about the smoke above the nuclear plant and delay with publication of the map of the lines of level of radiation. The delays with the transferring of the compensation should be considered as a sufficient reason for the significant increase (for example, doubling) of the amount. The insurance companies should be punished for any delay with the promised compensation in a way, similar to that a poorly-designed nuclear reactor punish the humans for any delay with delivery of the next portion of the coolant.

The Law should force the operators of the nuclear plants to make contracts with the insurance companies at the conditions mentioned above. Then, there are hopes, that the insurance companies will force the owners of the nuclear plants to build up the safe reactors and to dismount the old ones. This should be a necessary additional reinforcement to the total prohibition of building of nuclear reactors above the ground.

Let the reactors be insured for the earthquake of magnitude 10 by Richter scale; id set, it is assumed that even if all the stuff around felt down, but the nuclear plant still works and is ready to provide the electric power supply as soon as the electric power lines are recovered. Then, the nuclear companies will have to explain to the insurance companies (not to citizen not to the governments) that the Richter 10 earthquake will never appear. This should be problems of the nuclear companies and the insurance companies, not problems of the government and even less – problem of the citizen.

P.S.: Recent updates

It seems, there was no precedent to merge the problematic reactor into a water, although such projects are under discussion .

2011 April 28, the nuclear reactors at the Tennessee Valley Authority were shut down due to the weather conditions and left without external power supply; the emergency diesel generators are expected to save Tennessee from the the nuclear disaster. Hope for the gool look; avos the diesel generators will not fail.

With the delay of two months, the official map of contamination is published (and shown at the article Fukushima disaster). While the weather agencies do not post daily at their sites the map of isolines of the density of the ionizing radiation (as they do with isotherms and isobars), the humanity is not ready to use the nuclear energy. If they cannot provide such a map even without the nuclear accidents, there is no hope that they provide it if an accident. Is this ignorance, laziness or sabotage? Perhaps, there is black market of such maps among land owners who deal with properties in vicinity of the contaminated regions... This may indicate to the strong corruption of the administration, that is not compatible with the safe use of the nuclear energy.

References

http://www.guardian.co.uk/environment/blog/2013/mar/11/nuclear-reactor-operators-financially-liable-disasters Antony Froggatt. Nuclear reactor operators must be financially liable for disasters. Monday 11 March 2013 15.18 GMT.