22 Ноября 2019 | пятница | 14:17
Energoterra

The World's Leading Uranium Producer

Февраля 20, 2014

The paradox of Kazakhstan is that being one of the global leaders in explored uranium reserves, the country has no domestic nuclear power plant. However, if we go back in time, it is worth to say that the world’s first commercial fast reactor was manufactured in Kazakhstan. And in the long view, there is promising background for development of domestic nuclear power industry.

Pioneer
As of today, Russia is the worldwide leader in the fast reactor technology thanks to Beloyraskaya NPP power unit with BN-600 reactor which has been fully functional for more than 30 years. However, it is worth to mention that this success was encouraged by its predecessor – primary sodium fast reactor BN-350 commissioned in the city of Shevchenko, Kazakh SSR (now the city of Aktau, Republic of Kazakhstan) which was a part of Mangyshlak (Mangistau) Nuclear Power Complex (MNPC). Having been designed for 20-years lifetime, the reactor had been in service for 25 years free of any nuclear emergencies or radiation accidents, and could have been operated for a longer time had it not been for external reasons.

Back in the 1950s, Alexander Leipunsky, the “father” of the fast reactors development program and a member of the Academy of Sciences of the Ukraine SSR, prepared a then infant nuclear industry of the Soviet Union for construction of a pilot NPP based on a fast reactor. Initially, a BN-50 reactor was considered. Then, a bold move was made to BN-250 project which finally transformed into BN-350. In 1959, Yefim Slavsky, the legendary director of MinSredmash, has made a decision to locate the construction site for the pilot fast reactor in Shevchenko, Kazakhstan, on the territory of Mangyshlak peninsula (now Mangistau region).
In 1962, a Decree of the Central Committee of the Communist Party of the USSR and the Council of Ministers of the USSR ‘On construction of a commercial dual-purpose fast reactor BN-350 as part of the CHP plant construction program’ was issued, followed by the respective Minister’s order.
Later, the term “dual-purpose” afforded grounds for rumors saying that BN-350 was all but the center of plutonium production for the Soviet nuclear weapon. However, specialists affirm that in the materials produced by BN-350, “the content of high isotopes of plutonium was lower than in the weapon-grade plutonium so using it in military purposes would be really complicated; but it was suitable for preparation of uranium-and-plutonium fuel blend for nuclear power plants”. Thus, the term “dual-purpose” is interpreted by the specialists as being used not only for power generation but also for production of water vapor with high parameters for a seawater desalination plant. There is also the third opinion: it was not only the power industry program but production of new fuel for NPP. Then again, considering the historical aspect of those years, all the above opinions are acceptable.
Initially, the reactor was scheduled to be commissioned in 1970. However, due to difficulties of manufacturing of non-standard equipment, it was postponed to 1972. For the first time ever, in the process of loading fuel assembly to the reactor, the chain-reacting amount was achieved on November 28, 1972. Then, the reactor was shut off, and the first demonstration physical start-up was made on November 29 in the presence of the Central Committee. So, that date is considered as the date of birth of BN-350 reactor. And the power start-up (start of electric power generation) was effectuated on July 16, 1973. For reference: the French fast reactor FENIX 250 MW was connected to the power system 6 months later, in December 1973. 
However, traditional interpretation of a “power unit” (reactor-generator-turbine complex) may not be used for BN-350 due to its second function (desalination of sea water). Especially for that, back pressure turbines were designed that are usually used at regional CHP plants compared to condensing turbines utilized at large thermal power plants (GRES). Superheated steam from VN-350 reactor was fed via steam generators to the steam bypass common for all three turbines 50MW(el). After having travelled through the turbines and after the power was generated, the underused vapor was fed to desalination plant able to produce up to 120 000 cubic meters of fresh water per day. That is why “350MW(el.)” in the reactor’s name means NPP rated electrical capacity, as if its heat was not used for the needs of the desalination plant.
 
Research and production
A three-loop cycle for heat transportation from the reactor to the turbine (sodium-sodium-water) was used on BN-350 reactor system. Later, such three-loop cycle has become traditional for primary sodium fast reactors but the reactor design itself remained unique: loop-type. It means that in the reactor vessel (which even back then was already double as a Russian nested doll, i.e. primary tank and guard tank were placed one inside the other), there were only the reactor core, coolant pressure chamber, control and protection system, and refueling system. Intermediate heat exchangers, main circulation pumps, and other equipment of the primary cooling circuit were located outside of the reactor vessel. There were six primary circulation loops (five operational loops and one standby loop) that could be blocked off with the help of special gate valves. Each sodium pipeline had its own guard vessel for leakage protection.
Even then, such bulky and complex arrangement of the sodium-filled equipment and pipelines received criticism from specialists due to potential leakage of inflammable sodium which on top of all would be exposed to radiation in the reactor core. So it is for a good reason that without waiting for a BN-350 start-up, development of another new-generation fast reactor BN-600 was commenced in the USSR. BN-600 was an integrated reactor where all primary coolant equipment including pumps and heat exchangers was laid inside the reactor vessel. At the same time, there were practically no outside sodium pipes of large diameter, which significantly improved fire and radiation safety of the reactor system.
Taking into account specific characteristics of fast-neutron nuclear reaction, initially the reactor core with two degrees of U-235 fuel enrichment (17% and 26%) was used at BN-350. Thereafter, with due account of operating experience, the reactor core was divided into three degrees of fuel enrichment: 17%, 21%, and 26%. This exact ratio was inherited by BN-600.
Over the time of operating BN-350, lots of researches were made that served as background for further development of the Soviet (Russian) fast reactor technology. There were tests performed for the neutron field effect on different metals used to manufacture fuel assembly shells and on other structural materials. There was justification provided for the use of fast reactors for effective combustion of actinoids being the most troubled long-life radioactive waste of other NPPs, i.e. a solution was provided for the critical problem of burning accumulated radioactive waste of nuclear power industry. A few different types of the uranium-and-plutonium fuel blend were tested, and it was experimentally proved that nuclear fuel cycle may be closed on such reactors and with such type of fuel.
Finally, with the help of BN-350, an isotope production technology was developed for medicine and industry. In the fast-neutron spectrum, Co-60 isotope was produced which does not occur in nature but is widely used in radiosurgery, non-destructive testing, activation of seed grain of cereal and green crops, food and medical supplies sterilization, neutralization of industrial effluents, etc. Also, other much-in-demand isotopes were produced such as iridium, cesium-30, chrome-51.
A retired reactor
Since there was no experience in operating such type of reactor systems, designers have calculated the design service life of BN-350 hypothetically, based on minimum design capacity of the equipment – 20 years.  According to the results of the actual operation, this term was extended to 25 years. The reactor could have been operated for a longer time but it was brought to a stop by the Decree of the Government of Kazakhstan in April, 1999. Why did that happen? 
As always, there are a few reasons. Global recession in the end of the 1990s resulting in output decline and decrease in demand for products produced by BN-350 (electric power, heat, desalinated water). Political pressure of super powers (first of all, the United States) that were interested in elimination of potential sources of dissemination of nuclear materials. Refusal of Russian enterprises to provide scientific and technical support for the nuclear plant of a now foreign country without commercially reasonable pay level. Lack of other NPPs in Kazakhstan, thus no sense to establish a nuclear fuel cycle. And last but not least, as critics assume, -emigration of some key nuclear specialists that could not see any perspective for further application of their skills and experience in Russia and in Kazakhstan in the 1990s.
On the other hand, the world’s first commercial fast reactor BN-350 has become the global leader once again, talking about its decommissioning.
Spent nuclear fuel was unloaded from the reactor and packed in special casings. Russia was quite able to process the spent fuel using own resources since the technology of dealing with similar fuel assemblies of BN-600 was up and running there for a long time already, and the standard sizes of BN-600 and BN-350 fuel assemblies were the same. However, that was not done for some transnational reasons. The United States insisted on BN-350 shutdown and on long-term preservation (in effect, burial) of spent fuel under a specious excuse – so it does not fall into terrorists’ hands. A well-known Internet resource WikiLeaks has posted a memorandum of the US ambassador to Kazakhstan called ‘To the Management for the CENTCOM Commander General Petraeus’ which confirms special interest of the American official authorities to BN-350 and related matters. With the participation of the Sandia National Laboratories (USA), in the course of a meticulously developed covert operation, spent nuclear fuel of BN-350 containing 11 tons or uranium and 3.3 tons of plutonium (which hypothetically is enough to produce 775 nuclear warheads) was took out from Aktau by rail. It was transported for almost three thousand kilometers to the East Kazakhstan and disposed in a special repository of the National Nuclear Center (former Semipalatinsk proving ground), on “Baikal” site. However, Russia was able to participate in this project as well: packages for storage and shipping of spent fuel were manufactured by Sevmash plant. 
Eventually, spent fuel of fast reactor suitable for effective processing and production of fresh fuel for NPPs was in fact withdrawn from economic circulation.
Works related to decommissioning of BN-350 were performed by Kazakhstan along with American, British, European and Japanese companies. 
Liquid-metal coolant (sodium) was pumped from the reactor system to special tanks for further disposal. The remaining sodium was removed from the reactor vessel and its loops by hydrocarbonization method. Then, sodium was processed into 30% alkali with further processing it into geocement compound which is characterized by properties close to natural stone.
The reactor system will be put into long-term safe storage under observation for 50 years. Afterwards, the equipment will be disassembled and disposed. 
 
World's leading fuel supplier
Today, the nuclear industry of Kazakhstan is basically focused on production of ore and fuel for other countries. Kazatomprom is the national exporter of uranium, rare metals, nuclear fuel for NPPs, special-purpose equipment, double-purpose technologies and materials. There are explored reserves of natural uranium in Kazakhstan which amount to 20-25% of the global reserves. Actually, Kazakhstan may be called the world’s leading international supplier of uranium.
Nevertheless, the nuclear industry of Kazakhstan aims to change its activity, from raw materials to high-tech product supplies – fuel production for NPPs.
Kazatomprom is determined to become a vertically integrated transnational company of a full nuclear fuel cycle.
First of all, we are talking about conversion – pre-enrichment fluorination of uranium, i.e. production of gaseous uranium hexafluoride. In this field, Kazatomprom has been working together with Cameo Corporation that owns a conversion plant in Canada. A joint venture Ulba Conversion LLP was established for that purpose.
Second of all, enrichment, i.e. increase of U-235 isotope content from natural 0.7% to 3-4% suitable for thermal-neutron reactors. Here, Kazakhstan cooperates with Russia: a Russian- Kazakhstani joint venture Uranium Enrichment Center was established in the city of Angarsk (Irkutsk region, Russia). The energy-saving gas centrifuge technology will be used for uranium enrichment.
Third of all, production of uranium dioxide fuel pellets. This type of production was set up at Ulba smelter in the city of Ust-Kamenogorsk. For many years, the plant has produced uranium pellets for reactors designed in the Soviet Union (Russia) and operated abroad. In the future, it is planned to enter into fuel market for light-water and boiling-water reactors manufactured in Europe and US.
And finally, production of fuel assemblies for NPPs. An agreement was signed with AREVA (France) to develop a fuel assembly production line at the abovementioned Ulba smelter for French reactors. Besides, Kazakhstan came forward with an initiative to host an international nuclear fuel bank in the Kazakh territory under the aegis of IAEA. The banks provides for storage of low enriched uranium used for production of gaseous fuel elements for NPPs. Preparation of internationally recognized documents is scheduled for completion by the end of 2013.
Holding a course for NPP
They started talking about a need to construct a domestic NPP in Kazakhstan back in 2006.  In 2011, the President of Kazakhstan Nursultan Nazarbayev confirmed that initiative. The grounds are obvious: the Republic owns a quarter of the worldwide uranium  reserves, has required scientific resources, infrastructure and qualified staff experienced in operation of former nuclear power plant in Aktau. Besides, projected growth of energy consumption by the population, and industrial expansion will require up to 173 billion kWh of power by 2030, and the existing capacities are only able to generate 80 billion kWh. It is assumed that the new NPP will pay off in 15-20 years, and its lifetime will be 50 years.
Five sites are being considered for the NPP: Aktau, Bolke (Balkhash), Kurchatov (Semipalatinsk proving ground), Torgay (Kustanay region), and Zhambyl region in the South Kazakhstan.
Aktau certainly has the best shot: there is BN-350 infrastructure available, and a Caspian seaport is scheduled for development in the future which would require electric power as well. 
Also, apart from the site, Kazakhstan has to settle upon the required capacity of NPP power units: would medium-powered reactors (300 MW) be all right, or would the plant require popular high-powered reactors (1000-1200 MW), or should two plants be constructed each using a different type? Most probably, a medium-powered reactor will be chosen since it would not require additional expenses related to increase of transmission capacity of the existing Kazakhstani networks.
It is obvious that once the site and the NPP power class are selected, a call for an international tender will be made. Besides Russia, such countries as France, USA, Japan, China, Korea, and India might participate in it. As of today, there is ongoing cooperation with many of them already. For example, Kazakhstan is engaged in fuel production together with AREVA (France); Kazatomprom owns a 10% share in Westinghouse (USA); Japan Atomic Power Company and Marubeni Utility Services Ltd. have already discussed with Kazakhstan their participation in the NPP project (at this point, in terms of preparatory works and staff training only).
Truly speaking, not all of the abovementioned countries will be able to offer to Kazakhstan the reference medium-powered reactor. For this point, the main competitor of Russia is India that has already manifested its intention to participate in construction of Kazakh NPP. The Indians have set up their own production of pressurized heavy water reactors (PHWRs) (similar to Canadian CANDU) with small or medium power (from 100 to 540 MW) and are ready to export them to the neighboring countries.
As of today, Russia may only offer a water lumped power reactor VBER-300 which is designed on the basis of the well-reputed reactor of Antey nuclear submarines. It is quite possible that the VVER-640 project may be revived as well (it was developed to replace VVER-40 reactors and may be updated and brought back to life if necessary).
For Russia, construction of a nuclear power plant in Kazakhstan is not a vital project. Rosatom has quite an extensive portfolio of projects for construction of commercial high-capacity power units abroad, and development of a new high-powered reactor would require diversion of funds and human resources. At the same time, Russia is interested in Kazakhstan being a uranium supplier, and establishment of a Russian-designed NPP would strengthen the ties between the two countries. Besides, by launching a reference power unit of a medium-capacity nuclear power plant in Kazakhstan, Russia will get a pretty good credit in promoting such type of reactors on the global market. And the global market is really huge: power networks in many small or developing countries are rather weak and are not able to ensure power transmission from a large NPP.
Keeping that interest in mind, Russia even considers granting a loan to Kazakhstan for NPP construction. However, it will be only possible to make any detailed plans after Kazakhstan choses the site location and the capacity class and proceeds from intention to action.
 
Ruslan Novoreftov

Translated by Vladimir Alekseev

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