Vladimir Shlyomin

T

here
are two events of world significance in the history of the Russian nuclear power industry: Russia constructed the world first nuclear power plant in 1954 and had the most large-scale man-caused catastrophe owing to reactor explosion at Chernobyl NPP in 1986. Up to now these two landmarks, triumphal and tragic, dictate the fate of the industry which, the most successful in the field of high technologies, has to permanently right for further development.

For 50 years of experience the nuclear power industry managed to occupy the same place in the energy balance as the much more ancient hydraulic power industry. Meanwhile the process improvement was not so evident. In spite of new reactor ideas realized in demo and pilot reactor blocks, the industry is still within the bounds of the technologies of the past.
A channel-type reactor was installed at the world first nuclear power plant in the town of Obninsk. According to Head of Federal Agency of Nuclear Energy Alexandr Rumyantsev, this type of reactor has had a special role in the Russian nuclear power industry. It warranted nuclear weapons, then was used in the generation of electricity production, was in the lead of build-up of electric-converting facilities at the time when machinebuilding did not offer a manufacturing process for tank reactor.
High-power channel-type reactor is a nuclear reactor in whose fissile region there is a system of channels with accommodated heat-producing elements. Water is used as a heat-carrier with steam generated during boiling and delivered to turbines. During operation, on-load refueling can be done without reactor shutdown and cooling which improves economic indicators and ensures no-break power supply to consumers. The exploded reactor of Power Unit 4 of the Chernobyl station was of this type.
After the Chernobyl catastrophe the process and equipment applied at FSU NPP stood the fire of ecologic agencies and official institutions of many countries. According to Nikolay Sorokin, First Deputy of General Director of Rosenergoatom Concern, the agreement between EBRD and the Government of Russia is general of this standing: it contains instructions interchangeable with the demand for shutdown of power units of the 1st generation as not meeting security requirements.
In the meantime, channel-type reactors are widely used. They are in successful operation not only in Russia but other countries as well. Romney Duffey, Principal Scientist of Atomic Energy of Canada Ltd. (AECL), reports: "There are over 20 reactors of channel type in Canada and they generate 15 % of electricity in this country, the power being the cheapest one". Reactors of the same type have been also constructed in Argentine, North Korea, Rumania and, quite recently, China. It means that the world assessment and licensing of these units have been carried out. Romney Duffey goes on: "We are now elaborating a new project. Techno-economic parameters have been improved, security raised, cost reduced and construction schedule shortened. The project has been licensed both in Canada and USA".
In the Russian nuclear power industry high-power channel-type reactors account for a half of 22,240 MW of installed capacity. As affirmed by Nikolay Sorokin, during the time of operation these reactors generated 1.5 trillion kW/hr or 54 % of total electric power generated based on nuclear fuel.
According to the data of the Federal Agency of Nuclear Energy, 1000-MW reactors are installed in the power units of Leningradskaya, Kurskaya and Smolenskaya NPP and the most high-power reactor of this type (1500 MW) is installed in Power Units 1 and 2 of Ignalinskaya NPP in Lithuania.
Like any technology, channel-type reactors are being permanently improved and modernized. To close this field would mean a deep uncorrectable gap in the national power system. That is why, in spite of black-and-white demands of the public, the work goes on, with its great part dealing with higher reliability and security level.
Nuclear power specialists persuade that the repeat of the Chernobul catastrophe is impossible. They have done an in-depth situation study and clearly identified the reasons which resulted in the explosion of the reactor. Nowadays it is believed that a fatal coincidence of human incompetence and imperfect equipment has caused the breakdown.
Yuri Cherkashov, Chief Designer of channel-type reactor units, says: "Chernobyl is the result of serious deviations from operating regulations in several parameters. It so happened that at all the nuclear power stations with high-power channel-type reactors (Leningradskaya, Ignalinskaya, Smolenskaya, Kurskaya) the managing link of personnel had a practice of operation with such reactors. They were well acquainted with service regulations that oblige to steadily follow the requirements. As military personnel says, "each record in the army regulation is written down with blood", and it is true for the nuclear power industry. In the meantime not a single specialist with practice of operation at industrial reactor turned out to work at the newest block best in design and material state at Chernobyl NPP! There were skilled electricians, erection people …. anyone but nuclear reactor physicists who are to control the most critical process. It is impossible to explain now how it could have occurred".
"In principle, the control system of the station was not designed for a purposeful breach of order", explains Evgeny Adamov, Former Minister of Nuclear Power Industry. "Fool tolerance was not provided for. However there are no fools at NPP. The people who think to be very clever and therefore able to discover what is dangerous and what is not work there. It is their self-conceit that resulted in going beyond the regulations".
Design engineers acknowledge that during the Chernobyl breakdown the negative consequences of the parameters of the reactor in use at that time were revealed. Yuri Cherkashov says: "I would like to remind that new developments, new mechanisms have been launched since 1989. It gives us any reason to speak about a radical change in the situation in the Russian nuclear power industry".
First Deputy of General Director of Rosenergoatom Nikolay Sorokin affirms that based on the results of the analysis of the Chernobyl breakdown all normative documents have been revised. The requirements for training of personnel were stiffened at any block of nuclear power stations. A compulsory requirement of an available full-scale NPP simulator was included.
The international team assessed the reasons and consequences of Chernobyl as well as the general state of the nuclear power industry. It included Western experts headed by George Tajror whose technical career started with the first serious nuclear breakdown in Windscale in 1957. The team had been working for several years and issued a multi-volume selection of materials completed with the conclusion as follows: "The security level of the units of Soviet design and make conformed to the security level of Western blocks of similar age, that is, constructed at one and the same time".
After the Chernobyl breakdown, a lot of other international examinations had been conducted which involved a list of disadvantages of reactor units from the viewpoint of security and various recommendations on their elimination. In the opinion of Western specialists, by now Russia has done a lot so that there would be no motive to reason even theoretically about the repeat of breakdowns of Chernobyl type. Michel Chouha, a manager of high-power channel-type reactor projects, Institut de Radioprotection et de Surete Nucleaire (IRSN), France, reports:
"From March, 2002 till April, 2004 Russia implemented an international project for full expertise of Block 1 with channel-type reactors of Kurskaya NPP. As a result, a very detailed assessment of the present state of its security was obtained. Specialists noted that the modernization program fulfilled in the power unit was elaborated very well. It can be stated (and it is really true) that the present state of Block 1 of the Kurskaya station greatly differs from its before-Chernobyl state".
It was mentioned that the modernized or new systems afforded an elimination of the disadvantages detected by IAEA previously and a substantial increase of security level.
Michel Chouha goes on: "Improvement of nuclear security is a permanent process that never stops. As far as we know, individual programs for each power unit were made up. If the modernization program is extrapolated to the other units one may presuppose that in the next 7 to 10 years when such programs are implemented the state of these blocks will be as good as that one".
When stressing a constructive nature of relations between Russian and Western specialists, Nikolay Sorokin referred to an in-depth assessment of state of power units at Leningradskaya NPP made with the participation of representatives of Sweden, Finland, USA, UK. The memo, which acknowledged that the valid requirements of security level in Russia are in line with world strategy, was issued based on the results of the expertise
When Head of IAEA Hans Blix came to get acquainted with the post-breakdown situation he claimed that the Chernobyl lesson evidenced not that nuclear power plants should be shutdown but that the implementation of measures to raise security must be speeded up.
Blix said: "Nuclear power industry can work without such breakdowns that demand an evacuation of people. It can operate unweighted by nuclear waste problems when all tasks associated with fusion of this waste are settled during the nuclear fuel cycle and the waste to be buried in the ground does not change the natural radioactivity of the Earth which remains as it was created by the Lord. And the most essential is that there are technological possibilities to divide military and peaceful uses of nuclear fuel".
It is in this last point where, in the opinion of many Russian and world specialists, high-power channel-type reactors have certain advantages against reactors of other types. Moreover, they can use reduced-enrichment fuel and fuel reclaim, permit on-load refueling, that is, continuous operation for a long time. Therefore, when speaking about the future of channel-type reactors, it is important to be guided by not the shock caused among people by Chernobyl but a real evaluation of the presentday security level of this technology and the promise it offers


Shots:
• Block 1 of Kurskaya NPP
• First-born of nuclear power industry: Obninskaya NPP built in 1954 (now closed)