"The lessons of Chernobyl were learned in full": Advisor to the head of Rosatom - on new reactors and prospects for the development of the industry

— Vladimir Grigoryevich, we are talking with you on the next anniversary of the tragedy at the Chernobyl nuclear power plant (April 26, 1986).

What fundamental reasons led to this tragedy?

- The main reason is the human factor, the lack of understanding of the "physics" of the reactor at low power by physicists, the mistakes of the designers, leading to the inefficiency of emergency protection and, finally, the mistakes of the personnel who conducted the experiment.

The experiment was carried out in the most dangerous state of the reactor ("RBMK-1000." -

) at a power of about 10% of the maximum.

At this power level in the reactor, the density of the coolant and, as a consequence, the reactivity change dramatically.

The purpose of the experiment on the night of April 25-26, 1986 was an attempt to use the kinetic energy of turbines for emergency security systems.

The station workers first reduced, and then tried to increase the power of the reactor, turning off the automatic protection system in violation of all the rules.

The reactor was put into an unstable state, and the experiment itself ended in an explosion.

But it was not a nuclear explosion at all.

The power was equivalent to about 9-10 tons of TNT.

For comparison, in Hiroshima and Nagasaki in August 1945, there were explosions with a capacity of tens of thousands of tons of TNT.

In the process of investigating the causes of the disaster, it was proved that the RBMK-1000 uranium-graphite reactors can operate safely.

Yes, the reactor had certain technical flaws.

In particular, it is an emergency protection system.

The defect consisted in the fact that the emergency protection rods entered the reactor for a long time (total time - about 19 seconds) and had structural defects.

Today, the RBMK-1000 has a fast emergency protection installed and the shortcomings of the old one have been eliminated.

• Vladimir Asmolov, Advisor to the General Director of Rosatom State Corporation

• RIA News

• © Vladimir Trefilov

— What can you say about the RBMK-1000 control system in the 1980s?

Atomic scientists who encountered it complained that it was very difficult.

The work was extremely stressful, requiring incredible efforts.

- Yes, at the beginning of the operation of the RBMK-1000, the control system was indeed very complex.

The work of the operator could be compared to the incessant playing of the piano, and so on throughout the entire shift.

But now, of course, there are no such problems on modern RBMK-1000s.

— In general, how much has nuclear energy in our country changed in terms of safety and energy efficiency over more than three decades?

- After the accident at the Chernobyl nuclear power plant, a global analysis of the entire situation in the nuclear industry was carried out.

The lessons of Chernobyl were learned in full.

The knowledge base about processes and phenomena has significantly expanded, on the basis of which detailed calculation codes have been developed.

Strict safety standards and qualitatively new technical means of ensuring them have appeared.

The qualifications of the staff have also risen to a much higher level.

For example, modern power unit control systems are characterized by a high degree of automation and have "fool protection", that is, they insure engineers against erroneous incorrect actions.

The concept of “accident management” has come into use.

At the Chernobyl nuclear power plant, the disaster occurred in a matter of seconds.

It is impossible to control such an accident, it must be excluded by the physics of the reactor.

For accidents with loss of cooling, the situation is different.

Such emergencies must be under the full control of the operator.

If we talk about the security system at modern Russian nuclear power plants, then they are all multi-level.

Moreover, each security barrier is literally the last line of defense.

The newest Russian nuclear power plants are able to withstand a direct hit by an aircraft and an earthquake of up to 8-9 points, and all nuclear power plants built during the Soviet era have undergone a deep modernization.

It is also important that in Russia information about the state of each power unit is transmitted in real time to the industry situation and crisis center, the Ministry of Emergency Situations and other organizations.

— In Russia, RBMK-1000 are gradually being replaced by pressurized water reactors VVER-1200, which are also actively exported (Turkey, Belarus, Hungary, China, Bangladesh).

There are other pressurized water reactors (VVER-1000, VVER-440) with a lower power.

As far as I understand, they have a completely different principle of operation.

What are the main advantages of VVER-1200 over RBMK-1000?

Is it possible to say that it is more compact, safer, and easier to manage?

— Yes, you can.

VVER-1200 belongs to generation III+.

This is a fundamentally different reactor.

The VVER technology uses a double-circuit nuclear steam-producing vessel plant with a thermal neutron reactor.

The coolant and moderator is ordinary pressurized water.

This type of reactor is now dominant in the world.

Abroad, it is called Pressure Water Reactor (PWR).

In the sense of physics, this is one and the same installation, however, between Russian, French and American, of course, there are differences, including qualitative ones.

• Reactor hall of the Russian nuclear power plant

• © Press Service of the Leningrad NPP

In particular, the domestic VVER is superior to Western models in terms of fuel rod cladding materials (fuel elements), and, when compared with Westinghouse products, the quality of Russian materials is much better.

Earlier, a Russian fuel assembly, a French assembly and a Westinghouse assembly operated simultaneously at one of the Swedish NPPs.

According to the results of operation, our assembly showed incomparably better results.

It is also important that the world has accumulated a very large experience in operating pressurized water reactors.

This is a unified knowledge base that allows us to talk only about the residual risk of accidents at such nuclear power plants.

In fact, we guarantee that in the event of failures and other emergency situations, there will be no danger to personnel and the public.

By the way, since the late 1980s, we have been cooperating quite closely with our Western colleagues.

The fruits of these joint efforts were the development of a hydrogen safety system, a system for passive heat removal from a nuclear reactor to the ultimate heat sink, and the so-called "melt trap" - a design for localizing the melt in the core of a nuclear reactor.

It provides isolation of the foundation from the melt, subcriticality and cooling of the melt.

"VVER-1200" were finalized taking into account the "post-Fukushima" requirements.

The probability of a situation occurring at our pressurized water reactor, which was at Fukushima, is approximately the same as a meteorite hitting a person.

Our VVER continues to evolve.

Now it uses boron regulation, when the primary circuit contains a mixture of water and boric acid.

But now we are developing a more advanced spectrally controlled pressurized water reactor.

This is a completely new word in nuclear energy.

If our calculations turn out to be correct, then our improved VVER will become the world's first generation IV reactor.

On the whole, there are still many tasks to be solved in Russia's nuclear power industry.

The main one is the transfer of the country's nuclear energy system to a closed fuel cycle, which will make it possible to introduce uranium-238 (U-238) into the nuclear cycle and transfer nuclear fuel to the category of renewable fuel, like the sun and wind.

— I can't help but ask about fast neutron reactors (FN).

This technology seems to be not new either - for example, the Beloyarsk NPP in the Sverdlovsk region has been operating on fast neutrons since 1980.

However, Rosatom is improving this type of reactor.

The Breakthrough project is currently being implemented - this is the so-called fast reactor BREST, a station for which is already being built in Seversk (Tomsk Region).

What is its difference from the previous BN reactors?

How effective will it be?

- The strategy for the development of nuclear energy in Russia is to form a two-component nuclear structure by the end of the 21st century.

The first component is thermal neutron reactors, the second is fast neutron reactors.

Russia is so far the only country in the world that has two operating "fast" power reactors (BN-600 and BN-800).

Now the design of the BN-1200 reactor with a sodium coolant has passed through all the references, and a low-power apparatus BREST (BREST-OD-300) with a lead coolant has been built. 

In general, BREST has very good "physics".

The power unit will be built approximately in 2027-2028.

For another five years, it will be in trial operation, during which the consumer qualities declared during the design will be tested.

• Russian fast neutron reactor

• © Rosatom

Today, I can say with all confidence that the future of nuclear energy without "fast" reactors is unimaginable.

Yes, while thermal neutron reactors are cheaper to build and operate, mainly due to proven technological solutions.

But there is a possibility that the situation will change in favor of fast neutron reactors.

The specifics of nuclear energy is that investments are long-term, and their positive effect is felt decades later.

— In conclusion, I would like to know your opinion about the future of nuclear energy.

After the accident at the Chernobyl nuclear power plant and Fukushima, multidirectional trends are observed.

In a number of developed countries, under pressure from environmentalists and so-called social activists, the rejection of the atom has become a trend.

Germany ended up in this camp, although neighboring France does not think of closing nuclear power plants, and another neighbor of Germany - Poland - is eager to build a new nuclear power plant.

What, in your opinion, is happening and what role in the field of peaceful atom is prepared for Russia, given the current political circumstances?

— History clearly shows that fluctuations in public sentiment, aggravation of international relations and sanctions often have a negative impact on the development of nuclear energy.

On the other hand, it never developed linearly, there were always ups and downs.

It is quite possible that under the current circumstances, the implementation period of some projects will shift to the right, perhaps some construction projects will be suspended due to disruption of supply chains and refusal to supply this or that equipment.

But, understand, these are subjective short-term factors.

The Russian Federation is the owner of the entire technological chain necessary for the design, construction and maintenance of nuclear power plants.

Therefore, my forecast regarding the future of nuclear energy in our country and in the world is positive.

As for the future of the peaceful atom, we see that in the West the forces that categorically oppose nuclear generation still retain influence.

However, last year and last winter showed how “well” European countries can live off renewable energy sources (RES).

Windmills and solar panels are a good solution, but only on a regional scale.

I think that in the conditions of the energy crisis and the shortage of hydrocarbons, reasonable people in Europe will pursue a policy based on the development of nuclear generation, and Germany, for example, will not be surprised if it restores the operation of a couple of power units.

Now the development of nuclear energy is actually closed on the production of electricity.

As before, such areas as the production of low-grade heat (for heating houses), high-grade heat (for producing hydrogen) and sea water desalination are still poorly developed.

There is no doubt that in the future these areas will receive an incentive for development.