Ship reactor

There are many different types of reactors. In the United States, the majority of the reactors are pressurized water reactors with graphite moderators. The Canadians built the CANDU reactor using heavy water as both moderator and coolant. Naval ship reactors are graphite moderated liquid metal cooled reactors. The detailed differences between the reactor types will not be examined, but the operating principal common to all will be discussed. 

First civilian ship reactor used in the ice-breaker Lenin, launched in the USSR. 

The first nuclear ice breaker was laid in 1956 and commissioned in 1959. This year (1999) becomes the 40 in the history of the Russian civil nuclear powered fleet, which consists of seven nuclear ice breakers and one transport (lighter carrier) ship. Nuclear powered ship reactor characteristics are presented in Table I. 

USE OF RUSSIAN TECHNOLOGY OF SHIP REACTORS WITH LEAD-BISMUTH COOLANT IN NUCLEAR POWER... 

An advantage of the Pb-Bi eutectic over Pb is its lower crystallization temperature of 125°C, which allows operation in a lower temperature range, where the corrosion problems of structural materials may be fairly easily solved (and, in fact, have been solved already). The Pb-Bi eutectic was considered as a coolant option for fast reactors back in the 1950s, but preference was given to Na, mainly for the reason of its better thermal properties. Pb-Bi was used for cooling ships reactors, and Russia - as the only country to have operated such facilities - has unique technologies for working with this coolant. 

LM. Ball and A. L. MacKinney, Nuclear Merchant Ship Reactor Zero Power Test—Core T," BAW-1202 (July 1060). 

XIX-7] GROMOV, B.F., et al.. Use of the technology of ship reactors with liquid metal coolant for construction of the high safety regional NHPP, Innovative Development Scientists of the Kaluga Region for the National Economy, (Proc. of Conf.) p. 83, Obninsk, Russia, 2000. 

Uranium Enrichment. Enrichment of uranium-235, from 0.711 percent as present in natural uranium, is essential to the economical operation of the light water reactors. The fuel life for these reactors is a function of the enrichment. With 3.4 percent U-235 fuel, the pressurized light water reactors produce 33,000 megawatt-days of energy/ metric ton during the three years the fuel is in the reactors. In the naval submarine and ship reactors using highly enriched U-235, the fuel life exceeds ten years. 

The complete integration of the primary circuit into the pressure vessel makes any appreciable leakage of radioactive water in the case of fuel can failures unlikely, which from the safety point of view is another advantage for the FDR as a ship reactor. Since to date no service station exists for nuclear merchant ships in Europe, a service station had to be... 

The technical feasibility of the nuclear ship propulsion for merchant vessels has been demonstrated by the nuclear ships Savannah and Otto Hahn. However, these first demonstration ships have not been economical. For the second generation of nuclear merchant ships an economical advantage compared to conventional vessels has to be proven. It is well-known that the higher investment for the nuclear steam generators has to be compensated for by lower fuel costs. Therefore in the design of future ship reactors efforts have to be made to reduce the fuel costs. But it is also possible to realize lower investment of the engine by further optimization of all components. 

The reduction of fuel costs can be realized by a higher power density, higher burnup values, and an optimal fuel management, as stationary nuclear power plants have shown in the past. But the experience with these large power plants cannot be applied without modifications to nuclear ship reactors mainly because of the relatively small power requirements of ship units. 

Another disadvantage for nuclear ship reactors is the high fabrication cost of the fuel elements which are implied by the short elements and the low number of fuel assemblies fabricated in one run. By using a standard fuel element or part of it, it is possible to reduce these costs. An important reduction would be realized by building several ship reactors of the same type. 

---