The fifth international workshop for fast neutron reactor technologies organized by Institute for Physics and Power Engineering (SSC RF IPPE) was held in Obninsk on October10-11, 2007. Atominfo.ru asked IPPE's Director General Anatoly Zrodnikov to comment the results of this important event.

"ABR" can be deciphered in different ways

Please, tell us a few words about the event taken place at IPPE?

At the very beginning of the current millennium International Discussion Club was established under name "Strategic Small Club for fast reactors". An idea of its establishment belongs to famous scientist Mr. Fujio, who headed nuclear department of Japan at that time. The establishers of the Club are the representatives of four countries - Hermann Grunder (USA), Yoshi Fujio (Japan), Jacques Bouchard (France) and your faithful servant.

The work of the Club was initially planned without excessive pomposity. Under the aegis of this club the scientists were to gather for discussion of scientific-technical issues concerning fast neutron reactors development. At the moment of the Club establishment fast reactor direction was not so demanded as today. But if to remember, the fate of the whole nuclear power was under question a few years ago, and moreover, fast neutron reactors (fast reactors) were going through difficult times.

So in USA fast reactor program was closed at all. And the word "breeder" was under a ban there. Now the Americans can't get out of the political trap, into which they fell at that time. In my speech at the end of seminar I reminded to the Americans that the abbreviation ABR (Advanced Burner Reactor), which they use today, was initially deciphered as Advanced Breeder Reactor. Our Russian technologies correspond to the latter wording, and as a result of international cooperation on the basis of our Breeder and their Burner, Advanced Best Reactor could be received.

Within the Club regular seminars are held. This kind of communication gives the chance for specialists to speak freely on all actual issues. It bears its fruits. Our club is debating, and each its participant can tell its viewpoint.

These meetings are very useful for everybody; they give the chance for specialists to "be normalized". Of course, I understand that the participants present not the latest results. Some results are still secret, especially by those, who came ahead. The level achieved by American specialists in fast reactor development is somewhat higher than it was presented at the last seminar. However, it should be admitted that we are also not disclosing far from everything.

Nevertheless, I suppose that we should work together at the conceptual level, where we are talking about "proving existence theorem" for fast reactors. A competition will appear later, when we are talking about technological development.

Everything in ideology starts with definitions

As we suppose, the choice of Obninsk as a place for holding the international seminar for fast reactors wasn't accidental. What position does IPPE occupy in Russian program for fast reactors?

At first let's remember about one, the most important event in nuclear physics, which influenceв on all future program of studies. On October 10, 1932, seventy years ago today, the first artificial splitting of lithium nucleus was realized in USSR, in Kharkov Physical-Technical Institute. It was done by young Alexander Leipunski and his young colleagues (the eldest of them was 27). Thereafter Alexander Leipunski became the scientific director of IPPE and the founder of domestic scientific school for fast reactor issues.

If to tell about the role of Obninsk in nuclear power development, I am sure that almost everybody has heard about the first NPP. But few people know that BR-1 the first fast reactor on the European continent was put into operation in IPPE in the same year, 1954. My predecessors and teachers told that Kurchatov had made a strict division of nuclear studies by "spectra", i.e. Laboratory 2 (now Kurchatov's Institute) had to be engaged in real things - water and reactors with thermal neutron spectrum, but let's Laboratory "V" (now Institute for Physics and Power Engineering) is engaged in any "exoticism" like liquid metals and fast reactors. That's how it began.

Fast reactors and closed fuel cycle are an especial scientific ideology. It is necessary to have carriers (people and organization structure), so that this ideology might live. I can claim that today IPPE is the only organization in our country being a carrier of scientific ideology of fast reactors on federal level.

You know, everything in ideology starts with definitions. One can often hear a term "Fast reactors with closed fuel cycle". But fuel cycle can be only for fuel, but not for reactor! It is more correct to tell about nuclear power, which is based on fuel cycle with fast reactors. Today nuclear power is also based on fuel cycle. It is called "open" fuel cycle, by this reason problems of its "head" and "tails' arise. Problem of "head" - where to take fuel, problem of "tails" - where to put spent nuclear fuel (SNF) and radiation waste (RW).

Today both fuel supply and handling with SNF in Russian and in the world are based on radiochemical technologies. Creation of a new technological platform and conversion to closed fuel cycle should lead to that nuclear technologies will begin serving "head "and "tails" of fuel cycle. Fast reactors will become a key element of this nuclear fuel cycle (NFC), which will close the problems of "head" and "tails".

Hence it is easy to see the fatuity of debates about what reactor is better, thermal or fast reactor? Actually, these are elements of two different systems. In current system with open fuel cycle, properly speaking, fast reactors aren't necessary at all. Yes, they can fulfill such functions, which are inaccessible for thermal reactors, but the current nuclear power system doesn't require these functions. There is no necessity to breed fuel or to burn actinides and high radioactive fission products in open fuel cycle.

What can closing fuel cycle give? If to convert nuclear power to using ²³⁸U and ²³²Th as a primary raw resource, one can obtain very interesting result from philosophy viewpoint - the primary raw resource will be practically exhaustless - it will last for significant period, saying, more than 1000 years. In this case the secondary fuel can be accumulated as many as it will be required. In other words, nuclear power capacities will be defined not by limited raw resource, but technological and intellectual resources, which are reproducible. In its turn, it will mean an accomplished conversion of nuclear power into category of renewable energy sources.

So, let's get back to IPPE. The main mission of our institute is to extend system of knowledge of nuclear science and technology, strengthening ideological positions of A.I. Leipunski's school: the future of nuclear power is closed nuclear fuel cycle with multiple using nuclear materials in fast neutron reactors, able to supply extended breeding of transuranium fuel and utilization of long-lived components of RW. Technologies follow ideology doubtless.

BN-reactors of small series and new generation fast reactors

What projects are realized at IPPE in the area of fast reactors now?

I would like to repeat that our main task is to provide scientifically perspectives not for one-two-three years, but minimum for 10-20 forward. Of course, we also participate in many existing practical projects. Now, for example, we provide scientific maintenance of construction of power unit with BN-800 reactor.

Concerning the future of large-scale nuclear power, we pay constant attention to several problems at once. A part of our employees are engaged in directed fundamental-searching studies of conceptual character. For this purpose it is necessary to analyze a whole set of system questions connected with scientific and technical, ecological, economic and even political problems. All this should be taken into account at the system level already when developing concept of innovation nuclear power development.

Telling about modern nuclear fuel cycle, I have already noted that we are faced the problems of its "head" and "tails", fuel supply and handling of SNF, but today the second problem looks more priority. Actually, we have uranium minimum for 50 years that allows us to increase power capacities on the basis of well-mastered and time-tested "old" power technologies, but today the storages of SNF have been already overfilled.

So now we are developing fast reactors of two types - commercial fast reactors of small series for conversation period and commercial fast reactors of new generation. Early putting into operation of the first type reactors will give an opportunity to stop accumulation of SNF of VVER reactors and to carry out mastering technologies of closing NFC at industrial level. Commercial reactors of the second type will replace VVER reactors, which are under construction today, as they are decommissioned.

It should be admitted that BN-800 project is practically ready reactor of small series. Of course, we should consider all those knowledge, which were accumulated during period of "downtime" of this project and introduce necessary changes and modifications, improve and obtain modern project of fast reactor of small series. To serve own needs of Russian nuclear power in the part of handling of SNF of VVER reactors, up to 5 fast reactors of small series should be constructed and about the same number of reactors for serving those thermal reactors, which Russia construct abroad. At the same time we are developing commercial fast reactor of new generation, designed to provide a full closing of fuel cycle. Their intensive implementation will start after 2030, they should become the key technological element of closed NFC.

First of all, both these tasks are connected with BN-reactors development. By the way, BN abbreviation is deciphered "fast neutrons". Of course, actually these reactors are fast sodium cooled reactors. One more task, which we are traditionally engaged, is fast lead-bismuth cooled reactors. It is not an alternative to sodium. We consider lead-bismuth as addition to the program for sodium cooled reactors.

To take technology from future and to develop it today

Light metal in fast reactor is ideal as coolant, but when it contacts with air or water, famous problems arise. But heavy metal has very beautiful and very important property: heavy liquid metals (for example, lead or lead-bismuth) are very good for organization of direct contact heat exchange "metal-water". It removes the problem of walls that allows to decrease dimensions of heat exchangers from meters down to decimeters if not to centimeters. In other words, to decrease them ten times. It is very important in connection with necessity of mastering hydrogen technologies.

By the way, as to hydrogen production. First of all, it should be ecologically pure. Today we have somewhat simplified imagination - we will make a car powered by hydrogen, Н₂О-steam instead of СО₂ is realized from the exhaust pipe of this car, and ecological problems will be solved. Actually everything is more complicated. If we convert cars to hydrogen, nothing will be changed on the whole. It is necessary to convert to ecologically pure technologies of hydrogen production too. Nuclear technologies satisfy to this requirement. Now we are also working in this area - nuclear hydrogen power.

Our interests are also connected with small and middle power reactors for regional power. For Russia it is very important, if to remember that only 15% of its territory is covered by unified electricity grid. Reactor for regional power should be maximum reliable from the viewpoint of nuclear and radiation safety, fire safety, explosion safety and many others. All these aspects should be investigated. We understood it long ago, when we were developing TES-3 (large unit transportable nuclear power plant). In any case any small NPP is nuclear facility, which requires principally new level of respect than power plant using hydro carbonate fuel.

One of our proposals for regional NPPs is based on those developments, which were fulfilled for nuclear submarines (NS). Tasks for designing reactors for NS are similar to tasks of regional reactors development - for example, there is exactly the same restriction for number of operating personnel, the systems should be maximum automated, absolutely reliable and safe.

Using experience of NS reactors development, now we are taking part in development of fast lead-bismuth cooled reactor SVBR-100. SVBR pilot reactor is suggested to build at IPPE's site. This reactor is sufficiently safe in order to build it in the area of city.

Space nuclear reactor investigation line is reserved for us. Space nuclear installations are also fast neutron reactors. Of course, there nobody says about breeding ratio (BR), breeding of fuel in space isn't required. Other important properties of fast reactors are necessary there - compactness of the core and thermal physics of liquid metals. If you look at P_s (T_s) curve for sodium, you see that its boiling point under pressure of 1 atm is to 900°C. It is impossible to keep this level of temperatures in system with water coolant. But high temperature is necessary because in space heat unused during conversation can be removed only by one way - T to the power four.

It means that heat flow of absolutely blackbody is directly proportional to the forth power of its absolute temperature. - AtomInfo.Ru.

Thus, space nuclear reactors are fast reactors automatically. They are small compact and light, with high temperature coolant and long lifetime, as well as without poisoning effects that is very important. Naturally, IPPE is the ideologist of their development.

As you see, we really think about future. By the way, I am impressed by one of theories of growth, which looks briefly as follows: in order to succeed in business it is necessary to take technology from future and to begin developing it today, so that this technology would be ready to the moment, when future comes. The only thing that is important - technologies should be taken from future, but not from past or present.

SOURCE: AtomInfo.Ru

DATE: November 05, 2007

Topics: Russia, Fast breeders