Дата публикации: 29 августа 2021
Автор(ы): Vladimir MAKAROV →
Публикатор: Научная библиотека Порталус
Рубрика: ВОПРОСЫ НАУКИ →
Источник: (c) Science in Russia, №4, 2010, C.35-41 →
Номер публикации: №1630229861
Vladimir MAKAROV, (c)
by Vladimir MAKAROV, laboratory head, the Russian Research Center "Kurchatov Institute"
Russia is the world's only country to have a fleet of civil atomic (nuclear) vessels. More than 50 years have passed since the first of them, the Lenin icebreaker, was built. Overall, nine iceboats of three generations have been built at shipyards of this and other countries to pilot ships all through the Northern Sea Route and keep it open. The Sevmorput, the world's only nuclear-powered cargo vessel, is still in service. What with the expanding hydrocarbon production in the Arctic regions, the role of nuclear vessels increases significantly.
NUCLEAR-POWERED SHIPS GET OLD, TOO
Let us remember the euphoria of the 1970s, and the galloping oil prices. Scores of publications appeared then in the scientific and technical literature suggesting that heavy-tonnage nuclear-powered cargo vessels and tankers should be built. At that time our country started building her first icebreakers*. In a period from the 1970s to 1991 five atomic icebreakers with double -
* See: Zh. Alferov, A. Rodionov, "Naval Might of Russia Was Born Here", Science in Russia, No. 6, 2001; Zh. Alferov et al., "Main Strike Force of Russian Navy", Science in Russia, No. 1, 2006.-Ed.
reactor energy plants came off the building ways of the Baltic Shipyard in Leningrad. They were the Arktika, Rossiya, Soviet Union and Yamal. At the end of the 1980s two atomic vessels, the Taimyr and Vaigach, with a restricted draft and a home-made single reactor plant of 40,000 h.p. capacity, were built for the USSR at Värtsilä shipbuilding ways in Finland. In 1988 the Sevmorput, a unique lighter of the ice category, was put into operation. Three years ago, after a 15-year pause, the 50 Years of Victory* was built, a nuclear ship remarkable for a greater displacement and a modified shape of her hull.
However, giant ships capable of longtime independent navigation and making no port calls for years are on their way out. The first atomic icebreaker the Lenin was withdrawn in 1989 and the Sibir icebreaker, of the second generation of iceboats, in 1993. In October 2008, the Arktika icebreaker was laid up, her reactors serving for 33 years, or above 175,000 hours of the specified and extended lifetime. The lifetime of her "sisters", too, is running out, for all the repairs, upgradings and streamlined safety standards. By the end of the next decade only the 50 Years of Victory icebreaker might be capable of adequate performance. Therefore, shipbuilders are focusing on new atomic vessels capable of operating, by changing their draft, both on the main lines of the Northern Sea Route and in its shallow water areas.
"EXPERIENCE, SON OF TRY AND ERROR..."
The idea of creating such all-purpose icebreakers occurred at the end of the 1970s at the Leningrad Central Research Institute of the Navy in the laboratory headed by Loliy Tsoy, Dr. Sc. (Technol.). In one recent publication (The Atomic Strategy of the 21st Century journal, 2008, No. 36) he explained in detail why shipbuilders had to think of upgrading the performance of such vessels. This problem popped up soon after the Arktika icebreaker was put into service. Up until that time we had no experience in running such powerful leader icebreakers operating jointly with other transportation vessels, still in their cradle. It was essential to know rational correlations between the size and capacity of atomic vessels, and to solve a number of problems related to navigation in shallow waters.
The Arktika icebreaker with its 11-m draft had depth limitations; it could not transport cargoes via the major Siberian seaport of Dudinka in the lower reaches of the Yenisei. In 1978, the Captain Sorokin diesel icebreaker was built for this purpose. In practice, however, it was not quite up to the mark, and a heavier shallow-draft vessel was needed, not depending on the fuel reserve. This fact is very important, as high-power vessels call for more fuelling, which leads inevitably to deeper draft. The problem was solved by the Taimyr and Vaigach icebreakers.
Heavy-tonnage vessels, for which a wide canal had to be laid, as well as the all-year traffic, called for a larger nuclear icebreaker. In addition, an optimal correlation had to be found between its capacity and displacement.
Drawing upon their experience, towards the beginning of the 1980s experts of the Central Research Institute of the Navy saw that a new icebreaker was to have somewhat higher dimensions and to provide for a good icebreaking capability at restricted draft. In the
* See: A. Chechurov, "Champion Among Atomic Giants", Science in Russia, No. 3, 2009.-Ed.
ensuing years it became possible to validate this idea, and today icebreaking fleet further development prospects hinge on such kind of iceboats.
DUAL-DRAFT ICEBREAKER FOR THE ARCTIC
In St. Petersburg engineers at the Central Design Office "Iceberg" suggested a multipurpose vessel, one that was able to change her draft from 8.5 m in shallows to 10.5 m in deep-sea waters. It could do that just within a few hours. To increase the mass of the atomic ship and place her screws to a depth sufficient for navigation in heavy ice conditions, it became necessary to take on board liquid extra ballast, namely, approximately 8-9 thous. tons of seawater could be enough for going 2 m deeper. This way, the vessel could use efficiently its capacity and actually replace the Arktika and Taimyr type atomic vessels.
The icebreaking capability of the suggested all-purpose iceboat had to reach 2.8-2.9 m for piloting heavy-tonnage ships. Besides, thanks to the modified hull form it was enough to have a shaft power of 60 MW (the Arktika had 49 MW).
To ensure an adequate traffic in the Kara Sea three such dual-draft icebreakers could replace five conventional iceboats. This would cut building and repair costs. Besides, the down time of two types of atomic vessels would be cut in the river-sea docking places owing to a through piloting by one vessel.
In the summer-autumn period such vessels can operate also in eastern regions, thereby their capability of overcoming a three-meter ice coat would allow to extend the navigation time.
With its width being 5 m more as compared with the Arktika, the new icebreaker will be able to pilot heavy-tonnage vessels along the Northern Sea Route already in the near future. Experts say larger transportation volumes are to cater the marine export of oil and gas to Europe from the fields of the Yamal Peninsula, the basins of the Ob, Yenisei and Lena, and also the Barents Sea (the Timano-Pechora oil-and-gas province*, the Stokmann gas-condensate field, the Prirazlomnoye oil field**, and
* See: M. Roshchevsky, N. Ladanova, "Komi's Academic Center", Science in Russia, No. 4, 1999.-Ed.
** See: Ye. Velikhov et al., "Gas, Oil and Ice", Science in Russia. No. 3, 1994; N. Bogdanov, "Russia's Shelf, Its Riches", Science in Russia. No. 4, 2003.-Ed.
others). Ship navigation in the Eastern Arctic can be stimulated by exports to countries of the Asia-Pacific Region of polymetals and apatites from the Tomtor deposit in the Republic of Sakha (Yakutia), and tin concentrate and coal mined in Chukotka. Experiments carried out in the ice basin show that 40 m wide vessels with cargoes of minerals can follow an all-purpose icebreaker non stop, breaking thereby the edges of the canal laid in the icefield.
A new generation icebreaker (Project 22220) is being developed at the Central Design Office "Iceberg" (St. Petersburg), specializing in icebreakers and vessels of the similar class, including nuclear-powered ones. Here in 2009 the engineering design of the new icebreaker was completed by the team of Chief Designer Vladimir Vorobyov, Cand. Sc. (Technol.), who had designed the Sevmorput lighter. As a rule, it takes 7-8 years to build a nuclear-powered vessel. Consequently, the new all-purpose iceboat will be commissioned after 2015.
The work on a dual-draft icebreaker gave birth to a reactor of a new generation. The previous OK-900 setup (and its modification KLT-40) designed in the 1960s did not meet modern standards of resource characteristics and endurance. Besides, one had to upgrade the mass and dimensions of variable draft icebreakers.
The engineering design of the innovative reactor RHYTHM-200 developed by the Experimental Design Bureau of Machine-Building named after I. Afrikantov (city of Nizhni Novgorod) was ready in less than two years. In December 2009, it was approved by the Scientific and Technical Council of Rosatom State Atomic Energy Corporation.
Specialists of the Nizhni Novgorod bureau, namely, Chief Designer Yuri Panov, Cand. Sc. (Technol.), Division Head Vitaly Polunichev, Dr. Sc. (Technol.) and their colleagues drew upon their experience of many years in running shipboard nuclear setups; in addition, they applied fresh ideas towards better reliability and safety.
The new reactor integrates the basic equipment of the reactor primary circuit with the reactor core* and
* Reactor core is a reactor's central part, in which a self-sustaining chain fission reaction with release of energy takes place,-Ed.
steam generator cassettes placed in one body, with circulating water pumps out in external hydraulic chambers like those operating today on atomic vessels. Another remarkable feature is the use of a higher-volume cassette core. It reduced considerably energy intensity, cut fuel enrichment down to 20 percent and increased the setup's lifetime.
The monoblock reactor has a slight hydraulic resistance of the main circuit of the heat carrier, and consequently, pumps of much lower capacity can be used. The next scheduled recharging of the reactor fuel assembly can be actually carried out only in 7 years. This is a significant advantage over the icebreakers in service, as at present they are replaced every 2.5-3 years. Besides, RHYTHM-200 has a minimum mass and dimensions.
The Russian Research Center "Kurchatov Institute" supervises the design of a dual-draft atomic icebreaker. Its researchers used mathematical models to study the dynamic characteristics of the reactor, they made neutron-physical calculations of the reactor, assessed the water chemistry conditions and the possibility of a controlled relaunching after a long shutdown; also, they explored the conditions of surface boiling on fuel elements.
RHYTHM-200 is certainly a significant stride in the development of nuclear technology. Integrated arrangement, lower energy intensity of the reactor core and other structural solutions increase the safety, reliability and efficiency of the reactor considerably. Besides, on account of its high modernization potential, this reactor is a trend-setter for decades to come, for it can be installed not only on ships but also at offshore nuclear power plants and desalination complexes; it can become part of local power sources, including offshore drilling platforms and structures for the surface and underwater mining and processing of oil and gas.
ATOMIC POWER PLANT AT SEA
With reference to the future of shipboard atomic power, one should mention offshore (floating) atomic heat power plants (OAHPP). Irrespective of the type of reactor, this one is considered an onboard plant. (Small wonder that the first American OAHPP was built in 1966 on the basis of the Liberty cargo ship.) The design of such a reactor and all its components should meet the rules of the Russian Maritime Register of Shipping, the appropriate normative documents of Rostekhnadzor Inspection and the International Maritime Organi-
zation*. It is not accidental that the Experimental Design Bureau of Machine-Building named after I. Afri-kantov suggested an updated version of the KLT-40C reactor setup designed more than 35 years ago for nuclear icebreakers to be used for the Academician Lomonosov offshore power plant now under construction. The service life of this element was extended to 40 years thanks to measures to bring down the effect of neutrons on the hull material. Changes also affected the design of the reactor core. The problem was to lower the uranium enrichment of 235U isotope to values not exceeding 20 percent, thus meeting the conditions of the International Atomic Energy Agency for non-proliferation of nuclear weapons. For this purpose the channel structure of the reactor core on icebreakers was substituted for a cassette structure, which made it possible to raise the specific loading of uranium by 15 percent. Next, the height of the working part of heat elements was increased by one third. But changing the existing fuel composition in heat elements for a cermet (ceramic-metallic) one proved to be most efficient, as cermet was 2.5 times higher in uranium capacity, while other useful properties of nuclear fuel were still there.
OAHPP is a non-propelled vessel, on which two KLT-40C reactors of 150 MW heat power each are installed. They generate electric energy and heat, and transfer them to a transformer substation and a heat power station, respectively. The complex includes onshore facilities providing for the reception, transfer and distribution of the product to consumers. Likewise in this complex are hydrotechnical objects, protecting the water area of the offshore power plant from natural and technogenic effects. Some of them are providing communications with the seacoast. The rated capacity of OAHPP is 70 MW.
Work on the construction of this setup is already underway at the Baltic Works. Initially it was planned to build it at the Sevmash Production Association in Severodvinsk (Arkhangelsk Region). In April 2007, the Rosenergoatom corporate group signed an agreement of intent for building a flotilla of seven such OAHPP. However, because of business pressure in August 2008 this enterprise handed over the work order to the Baltic Works, a part of the Joint Industrial Corporation.
* International Maritime Organization (IMO) is a UN specialized agency established in 1948 in Geneva, which is responsible for high reliability and safety of navigation in international trade, and prevention of sea pollution.-Ed.
Model of an offshore atomic heat power plant.
Model of the RHYTHM-200 reactor for a universal nuclear icebreaker. Right, a double-reactor setup in section.
The ship is scheduled for launching later in the year (2010). Its all-out tests are planned for 2012. Vilyuchinsk, a town of submariners and a closed administrative-terri-torial entity on Kamchatka, will be her port of registration.
Her navigation will show how good the adopted engineering solutions really are. But one drawback is obvious even now, namely, the short reactor lifetime, which makes it necessary to refuel the reactor in the naval base. During the overhaul period (10-12 years) up to 8 sets of fissile cores are burnt out at the dual-reactor, they are put into onboard spent-fuel storages.
A good OAHPP needs a specialized reactor facility. On closer examination the RHYTHM-200 setup is quite up to the mark in this respect. Equal in capacity to KLT-40C, the RHYTHM-200 reactor can operate without refueling all through the overhaul period, thus ridding OAHPP of spent-fuel storages and, above all, making it do without refueling out at sea.
True, the reactor lifetime should be brought to nominal parameters. This will call for a bit of additional research and development connected primarily with the longtime serviceability of heat elements. Probably, it would be needed to develop a new water-chemistry regime of the primary circuit of the heat transfer agent streamline the industry producing heat elements, and upgrade manu-facturing techniques. All this is necessary not only for OAHPP but also for a new generation of icebreakers.
Are marine nuclear power prospects limited only to one type of reactor, i.e. the water-moderated one, and the reactor being designed now? This will hold on in the coming 10-20 years. It can be upgraded then and, if nec-essary, a new series developed. As to other reactor types (with a liquid-metal or gas coolant) that have such an asset as the higher efficiency coefficient, further research is needed into how expedient their use could be.
Опубликовано на Порталусе 29 августа 2021 года
Ваше мнение ?