Pressurised heavy water reactor

The successful operation of 500 MWe thermal power plants in India has enabled to fix PFBR reactor power as 500 MWe. Large sized FBR have not indicated any technologic d problems because of reactor size. Specific capital cost is lower for 500 MWe than for a lower power, say 250 MWe. The design and development efforts needed for 500 MWe and 250 MWe plants are comparable. Pressurised Heavy Water Reactors (PHWR) of 500 MWe are under construction in India. Constructability of 500 MWe PFBR components has been assessed and adequate industrial capability exists within the country. 

TABLE H FUEL CYCLE WASTE DATA FOR 1000 MWe (Annual figures) (Pressurised Heavy Water Reactors, INDIA)... 

Boiling Water Reactors (BWR), Pressurised Heavy Water Reactor (PHWR) and Pressurised Water Reactor (PWR)... 

AECL Pressurised Heavy Water Reactors Candu stations, 1979-1984. 

In India, nuclear power stations of the Pressurised Heavy Water Reactor type are in operation in different parts of the country. Two boiling water reactors are in operation at Tarapur. Some of these reactors have completed more than a decade of operating life. Need has been felt to decontaminate the reactor systems and components in order to reduce radiation exposure to operating personnel. A Research and Development programme was therefore undertaken to develop dilute chemical formulations suitable for decontamination of our reactor systems. 

Velmurugan, S., et. al, "Evaluation of a dilute chemical decontaminant for pressurised heavy water reactors". Nuclear Technology, Vol. 96 (Dec 1991),... 

Vijayan et al. (2000)). The same is true for other loop geometries like the figure-of-eight loop used in Pressurised Heavy Water Reactors (PHWRs). For the figure-of-eight loop, the heater power used in the Gr is the total power of both heaters. The equations are also applicable for identical parallel-channel or parallel-loops systems if the parallel channels/loops are replaced by an equivalent path having the same hydraulic diameter and total flow area. 

VUAYAN, P.K. Investigations on the single-phase thermosyphon phenomenon in a figure-of-eight loop relevant to pressurised heavy water reactors, Ph. D. thesis, Indian Institute of Technology, Bombay, 1988. 

The purpose of this section is to compare the features of the RBMK reactor operated at Chernobyl with reactor types pertinent to the UK. It will be recollected that the RBMK covers a large number of reactors and the comparisons made are indeed with Chernobyl No. 4. The UK reactors covered are in three classes the commercial reactors now built and operated or in commission (Magnox and Advanced Gas-cooled Reactor (AGR)) the prototype Steam Generating Heavy Water Reactor (SGHWR) and Prototype Fast Reactor (PFR) that have comparable performance to commercial reactors and the proposed Pressurised Water Reactor (PWR) or Sizewell B design which, it... 

Nuclear reactors are classified by their neutron energy level (thermal or fast reactors), by their coolant (water, gas, liquid metal) and by their neutron moderator (light water, heavy water, graphite). Most existing plants are thermal reactors using pressurised (PWR) or boiling water (BWR) as a coolant and moderator PWR and BWR together represent more than 80% of the commercial nuclear reactors today, of which PWR accounts for 60% alone (Olah et al., 2006). 

This section provides a comparison of power reactors built in the UK with the Soviet RBMK. But it is worth recollecting that, elsewhere in the world, other types of power reactors are in use. The most widely built reactor is the Pressurised Water Reactor (PWR) but the second is the Boiling Water Reactor (BWR), a light water reactor in which, like the RBMK, steam is generated in the core and passed to the turbines in a direct cycle. Light (i.e. ordinary) water is used as coolant and moderator. The Canadian industry has developed the CANDU series of reactors, with limited export to India, etc., which have many pressure tubes to retain the coolant, as in the British SCHWR and Soviet RBMK, but are heavy-water-cooled and moderated. 

The reactor core was housed in a large vessel or tank called a calandria, which contained the heavy water moderator. The pressure tubes containing the fuel elements passed vertically through this tank. The heavy water in the calandria was not pressurised and formed a separate circuit from that of the main coolant in the pressure mbes, which was light water. The light water coolant was pumped up through the pressure tubes past the fuel elements in the tubes. The water then boiled in the core, and the steam produced was separated from the recirculating water in an external... 

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