Vladimir Kagramanian is doctor of engineering since, assistant of director general of the State Scientific Center of the RF- Institute for Physics and Power Engineering (SSC RF IPPE) for innovation technologies in nuclear power.

Main goal - transition to ²³⁸U

Could you comment the situation with uranium in Russia? Do we have enough uranium for our nuclear power plants?

The question "Is uranium enough or not enough?" is rising from the start of the nuclear power development. I think that the question sounds incorrectly. My point of view is that uranium will be continually found, and natural uranium will be enough for a long period. The main question is: Can we use technology with the smallest part of natural uranium used (less 1%)?

If we look at the resources of natural uranium, when using the smallest part of natural uranium today, mainly, its isotope ²³⁵U, we have to say uranium reserves are less than oil reserves and they are ten times less than natural gas. There is no sense to develop nuclear power on such technology, as this technology, being developed and with uranium resources exhaustion, will leave a problem of spent fuel in contradistinction to power based on organic fuel.

I would say - there is a lot of natural uranium. Our problems are connected with technology, because today we use only the smallest part of uranium reserves. The major part of the mined natural uranium in the kind of isotope ²³⁸U is accumulated mainly in waste as result of uranium enrichment and partially in spent nuclear fuel (SNF). Nuclear power can't develop wide-ragingly on the basis of this technology for a long period and with aim of replacement of organic fuel.

Do you consider that it is necessary to transit to reactors-breeders?

Breeders, fast reactors - they are all technical terms. We must transit to another fuel, namely to ²³⁸U, to begin its intensive use. We should transit to such technologies, which allow in its turn to transit to ²³⁸U. If we can start to use this isotope on large scale, it will be sense in existence of nuclear power, since the resource problem will be fully settled. Transition to ²³⁸U requires a closing of fuel cycle that can simultaneously contribute to solving waste problem.

I wouldn't say certainly about breeders or fast reactors. I would formulate the question like this - we need technologies of transition of nuclear power from preferential use of limited resources of ²³⁵U to preferential use of ²³⁸U, the reserves of which are colossal. These are technologies of SNF reprocessing and multiple recycle of plutonium together with ²³⁸U extracted from SNF in reactors with breeding gain (BG) more than 1. Today it has been demonstrated that such BG is achieved in fast reactors with sodium coolant.

When is it necessary to introduce fast reactors?

I think fast reactor developers make an ideological mistake. They often say like this - when ²³⁵U exhausts or the prices for it increase sharply, then fast reactors will be needed. Under these conditions discovery of new deposits of natural uranium or decrease of the pace of nuclear power development automatically postpones the time of introduction of fast reactors.

However, today in nuclear power development there is a problem of increasing amount of spent nuclear fuel and absence of demonstrated decisions of final handling with it. If you note, now in the world the main goal is to find the answer to SNF problem. While such decision isn't demonstrated and SNF is continued to be accumulated, on the whole it is dangerous to develop nuclear power.

Long-term storage of SNF leads to loss of power potential of plutonium (down to 15%) due to ²⁴¹Pu decay, on the one hand, and to appearance of new ecological problems due to accumulation of high radiotoxicity ²⁴¹Am - product of ²⁴¹Pu decay, on another hand.

It seems that we can develop and commercialize fast reactors, aiming them initially to solve urgent problems connected with accumulation and long-term storage of SNF of thermal reactors.

Commercialization means construction of small series of reactors

Who can consume plutonium as a result of chemical reprocessing of SNF of thermal reactors? It is known that we have only one BN-600 reactor and BN-800 is under construction. Do you suggest using these two reactors for plutonium recycling? But there is a certain situation with 34 tons of weapons- grade plutonium, which is supposed to utilize in BN-800 reactor. How can we combine these two processes?

If the task of BN- reactor development is set up taking into account economy, it is necessary to say about commercialization of BN-reactors. It suggests construction of not one, but of small series of units, as well as of a plant for fuel manufacture.

Now we came to the situation when we are able to commercialize BN- reactor development line, i.e. to complete this reactor to commercial stage. Here we don't need to wait, when the price for uranium will rise or ²³⁵U will be exhausted. Our estimations show that fast reactors in limited quantity already today can fulfill the important mission for nuclear power- to solve the problem of accumulation of SNF of thermal reactors and to minimize the amount of ²⁴¹Am in fuel cycle.

For this purpose it is necessary to construct the small series of BN-reactors - up to 10% of total capacity of nuclear power in Russia. For Russia it is 4-10 GW (el.) till 2030 depending on number of new NPPs with VVER-reactors. Plutonium obtained as a result of SNF reprocessing of all VVER reactors can be fuel for these fast reactors! I repeat, from all VVER-reactors, because plutonium from 10 VVER reactors is enough for loading of one BN-reactor. In this series of fast reactors one BN-800 type fast reactor can fulfill mission on utilization of weapons- grade plutonium.

Can we manage with two task simultaneously - to begin activities on closing fuel cycle and utilization of weapons-grade plutonium?

It isn't a problem. If we solve power task of commercialization of fast reactor development line, in this case the main activity line at the initial stage will be reprocessing of SNF of thermal reactors. We must have power plant of RT-2 type serving the whole fleet of thermal reactors and giving 10-20 tons of Pu a year. Weapons-grade plutonium will be the small part in this balance.

What about plants? Will the plant for manufacturing MOX-fuel be the same for power and weapons-grade plutonium as well?

The plant for manufacturing MOX-fuel for BN-reactor could be one. There is no problem to use its production lines for manufacturing fuel with weapons-grade plutonium. This task will become even easier from the technological viewpoint than manufacture of fuel with power plutonium.

Politicians don't follow scientists

You mentioned MOX-fuel. But from another side there are many disputes about nitride fuel, what's your opinion about this issue?

You know I am researcher, investigator. It is always interesting for me to study something. The more problem is complicated, the more it is interesting to study it. But now I understand that the scientists can be so mad on their particular complicated long-term tasks so, not paying attention to solve more simple but vital problems of nuclear power development.

The politicians are interested in the results most of all, but the researchers are interested in problems. Our problem is that we always thought about problems, but not about the result.

If to go stage by stage, each task has several stages - justification of the theorem of existence, R&D activity, demonstration of serviceability, commercialization. To jump through stages and give promises means to bluff.

Today we can complete the projects for MOX-fuel to commercial level and solve important mission on the basis of this technology - to utilize plutonium extracted from INF of thermal reactors in BN-reactors. As to nitride fuel, it is necessary to continue investigations. If we successfully pass demonstration stage of nitride fuel and all its declared properties are proven, after this we will be able to say consciously whether we need this development line or not.

The largest mistake of the scientist is that if at the initial stage of the project he begins to persuade politicians that new reactor projects are better than existing. As a result, a serious crisis situation has appeared, because the politicians fail to understand the subject of discussion. Such words as MOX-fuel or nitride fuel are abstract for the politicians. It is difficult for them to understand what of directions is the preferable- good or best.

But nitride fuel is better than oxide by its characteristics such as BG.

Yes. It is better. But firstly it is necessary to develop it! It should be developed and tested in reactors; it will prove its serviceability. "Nitride" economic fuel cycle should be appeared. Mastering of nitride fuel includes the answers to many questions - where to manufacture it, where to take it from and what to do with it after its use in reactor? After all these chains would be passed, we will get arguments for choosing.

As to MOX-fuel we should understand that its technologies already exist. MOX-fuel is actively used in the world in thermal reactors. Reprocessing of MOX-fuel has been also verified in France. And today the question is - what parts of this technology must be demonstrated and what parts should be completed to the commercial level.

Advanced activity lines in the field of closed fuel cycle under R&D work stage- nitride fuel, vibropac-fuel, dry methods of SNF reprocessing- for all these, if we have money, fuel cycle should be substantiated at the experimental level and after this to go on to the issues of demonstration and commercialization.

We have a potential improvement of characteristics for new kinds of fuel and technologies on paper. However, there is a question: Do we need these characteristics already today, for example, larger value of BG and how much should we pay for it?

For this purpose it is necessary to consider how the first fast reactors characteristics will effect on the whole system of nuclear power. In this case you will understand that fuel characteristics of the whole nuclear power system will be defined for a long time - till 2050 - by characteristics of thermal reactors rather than fast reactors. The latter should pass the stages of commercialization and intensive growth of capacity in order to equal total capacity of thermal reactors. Economic indexes of the first fast reactors, their safety and reliability will be the key factors of success.

The French and Japanese fell into a trap

You mentioned France. But the French have own approach to use plutonium. They load it into their light water reactors (REP). How do you comment this approach?

I feel pity for the French, fallen into real a trap.

Fast reactor technologies and technologies of SNF reprocessing developed in France. The plant for chemical reprocessing of SNF of thermal reactors and fast reactor SuperPhenix were built. Construction of the new NPP with fast reactors for utilization of plutonium extracted from SNF of thermal reactors was scheduled. Everything went in this direction, but in 80-ies the needs in electricity in Europe began stabilizing due to increasing efficiency of electricity consumption. So the necessity of increasing capacity fell away. As a result, the French faced with the problem what to do with extracted plutonium?

A similar accumulation of extracted plutonium was acknowledged as inexpedient both in the UK and USSR (at RT-2 plant). Then the following idea had been arisen - in order to keep people and technologies, MOX-fuel can be started to use in existing light water reactors, and moreover, the adjacent Belgium has demonstrated this technology.

What did France get using MOX-fuel in thermal reactors? It became possible to decrease the SNF storages several times! Everything is reprocessed and plutonium is immediately used. But the task on reprocessing of irradiated MOX-fuel is now more complicated. There is a degraded isotope composition of plutonium, which is more difficult to recycle in thermal reactors. At the same time this irradiated MOX - fuel contains more minor actinides then irradiated UOX (uranium) fuel.

Take into account - when loading MOX-fuel in thermal reactors, you burn half of accumulated ²³⁹Pu and ²⁴⁰Pu being the valuable fuel for fast reactors and not deteriorating during long storage. At the same time the quantity of ²⁴¹Pu at the beginning and end of cycle doesn't change, it means that ecological problem connected with ²⁴¹Am accumulation for a long-term storage of SNF in the case of MOX-fuel will be the same as in the case of UOX fuel.

If mass of americium is small in "fresh" uranium SNF and it forms only after long storage, in the case of using MOX-fuel a significant amount of americium is formed immediately. Now we face a new problem, what to do with irradiated MOX-fuel? Plutonium can be used in fast reactors. But what to do with significant amount of ²⁴¹Am? Herefrom there is an interest to various ideas of specialized reactors - MA burners.

Now the Japanese fell into the same trap. Today they don't need new reactors, thermal or fast reactors. They shut down tens units for scheduled repair and they are calm passing during this moments. They aren't going to make mass construction of NPPs at the nearest time. They understand that fast reactors are the basis for future. But they like the French launched the reprocessing of SNF of thermal reactors before they have fast reactors.

On the political level Japan always claimed that it won't accumulate plutonium extracted. In this situation natural decision is to use MOX-fuel in thermal reactors. On the question "Why to go to deadlock?", they answer - what we can do in this situation?

The State Department and DoE can't agree

What about the Americans?

The Americans have own "cockroaches". They have another trap ahead. When they understood that the INF problem couldn't be solved by simple ways, they had to find additional variants. They considered all possible ways including accelerators but finally return to fast reactors as the most realistic way.

Today they say in America about the necessity of developing fast reactors for burning mass of plutonium and minor actinides accumulated by thermal reactors because they have enough amount of this accumulated substance.

Excuse me, is it a part of GNEP initiative?

Yes. An idea of fast reactor-burner with transuranium fuel including ²⁴¹Am is appearing. Up to a recent time the Americans didn't consider seriously the subject of INF reprocessing and plutonium recycling in fast reactors.

When USA and Russia only started to negotiate on the agreement for utilization of excess weapons-grade plutonium, the American side supposed to immobilize plutonium- simple to burry it. But Russia and other European states began to prove that there is more pragmatic solution of this problem - energy utilization of plutonium in reactors.

I would like to remind, that the Americans didn't think about recycle at that time. But it was impossible for the Americans to imagine that we could construct new fast reactors because at that time our country was breaking into pieces and we were begging for each penny. As a result, they agreed for utilization of MOX-fuel in light water reactors. As to Russia, luckily for us, the government of our country refused this way.

Today it is "funny and sad" to talk with American specialists. On the one hand, they understood the importance of fast reactors development for solving problem of plutonium and minor actinides, they say about burning, GNEP initiative, fast reactor-burner. On the other hand, they launched the program for utilization of 34 tons of weapons-grade plutonium in light water reactors that will lead to increase of amount of minor actinides in USA and new postponed problems already with MOX-INF.

The problem is that in USA different government departments are dealing with the issues of handling with weapons-grade plutonium and INF. The Americans themselves understand that they look strange today but the process had been started and to overcome thinking conservativeness isn't easy.

Moreover, they are going to increase their quota of plutonium to be utilized.

Yes, this is a result of non-coordination of actions of different USA government departments.

Is that the State department and DoE can't agree?

Exactly, some people consider that the solution of weapons-grade plutonium problem is the most important; other people suspect that nuclear waste is the major problem. And these groups are not connecting to each other in no way!

Lead and bismuth cooled fast reactor SVBR and BREST must prove their significance

If you please, I will ask you several questions on another theme. What's your attitude to such project as lead - bismuth cooled fast reactor SVBR?

I am calm about it. As an engineer I say like this - let's first demonstrate this reactor technology, show its feasibility and advantages of practical use. Only after this we can say if SVBR is promising or not.

What position can these facilities occupy in nuclear power?

SVBR can be the first module reactor, since it is known that lead-bismuth direction started as module direction at once. But other reactors also can be module.

SVBR doesn't close module direction for other reactor types. Just lead-bismuth technologies were developed as module reactors unlike fast sodium reactors. I can say that this reactor can be useful for regional power. But I repeat once more, let's show at first that this technology works and only in the case of success we will say how wonderful it is, but not vice versa.

It is clear. It seems that your opinion on lead development line will be exactly the same, won't it be?

Absolutely the same. Only for lead reactors it is necessary to get experimental justification of the theorem of its existence. The main problem of ENTEK is, in my opinion, that it wants to jump at once to the stage of commercialization without justification, it means to make a jump on empty place for account of "political will" and administration measures".

In my opinion, it would be a big mistake. It should be concentrated initially at experimental justification of lead technologies and build a small reactor. Only in this case lead will have future.

Thank you for interview for AtomInfo.Ru.

SOURCE: AtomInfo.Ru

DATE: August 23, 2007

Topics: Uranium, Russia, MOX-fuel, NFC, Spent Fuel