Reactor boiling light water

FIG. 20.2. Russian graphite-moderated boiling light water cooled power reactor, RBMK. 

Channel tubes (88 mm o.d. and 4 mm thick) are of welded design and contain fuel assemblies which are cooled by boiling light water. The upper and lower parts of the channel are made of stainless steel and the central part, located in the active zone, is made from a zirconium/2% niobium alloy. The central part is joined to the upper and lower parts by vacuum diffusion-welded stainless steel/zirconium transition joints. The channel tube is attached to the upper duct by a welded joint, and to the lower one by a compensator unit, which is necessary to compensate for the difference in thermal expansion of the channels and ducts without destroying the leak-tightness of the reactor cavity. This type of joint makes it possible to replace a channel during reactor shutdown. 

Pressure tube boiling light water, HWM reactor... 

Pressure Tube Boiling Light Water Coolant, HWM Reactors... 

Typical circuit for a boiling light water cooled heavy water moderated reactor. 

The Gentilly-1 pressure tube reactor was a 250-MWe HWM and boiling light water-cooled design fueled with natural uranium dioxide. The reactor concept had been developed in the early 1960s, and in 1966 the reactor was committed for construction. First, power was produced in 1971 and full power attained in May 1972. It was shut down in April 1979, and by 1984 had been decommissioned. 

CIRENE Is a pressure tube heavy water reactor cooled by boiling light water. A 40 MW(e) demonstration plant is under construction at the Latina site. The completion of the plant is scheduled for 1985. The realization of the Latina plant is carried out jointly by ENEA (the National Commission for Nuclear and Alternative Energy Sources) and ENEL (the National Electricity Generating Board) NIRA is the main contractor for the nuclear island. 

This group of characteristics identifies the components designed to generate non-nuclear steam or to separate moisture from the steam produced in the reactor. These characteristics do not apply to boiling light water reactors (BWRs) accordingly, for all characteristics concerning SGs at BWRs, data providers should enter "N/A". 

The MHT system transports heat from fuel rods to a steam drum using boiling light water as a coolant. The MHT system consists of a common circular reactor inlet header from which inlet feeders branch out to the fuel channels in the core. The outlets of the fuel channels are connected to tail pipes. The tail pipes carry steam-water mixture from the individual coolant channels to four steam drums. From each steam drum, four down-comers are connected to the inlet header. 

Let us consider the Canadian reactors of the CANDU-PWR type presently being built at Pickering. The Canadian General Electric has proposed a vertical version for these reactors, with the same channel and the same fuel (ref. 6). Let us see what would happen if pressurized heavy water was replaced by boiling light water in the channel. 

We believe that this is the best line to go along with, when thinking of boiling light water cooling in heavy water reactors. 

CIRENE is a reactor concept belonging to the family of the heavy water moderated and boiling light water cooled systems. 

This appendix provides additional materials (schematics, layouts, T—s diagrams, basic parameters, and photos) on advanced thermal (combined cycle and supercritical pressure Rankine steam turbine cycle) power plants and nuclear power plants with modern nuclear power reactors [pressurized water reactors (PWRs), boiling water reactors (BWRs), pressurized heavy water reactors (PHWRs), advanced gas-cooled reactors (AGRs), gas-cooled reactors (OCRs), light water-cooled graphitemoderated reactors (LGRs) (RBMKs and EGPs), and liquid metal fast-breeder reactors (LMFBRs) (BN-600 and BN-800)]. 

Decommissioning in Sweden will involve twelve nuclear power plants located at four different sites (fig. 1). Nine are of the boiling light water reactor type designed and delivered by the ABB-Atom company and three are of pressuriz light water reactor type delivered by Westinghouse (Table I). 

There are various types of nuclear power reactors, including boiling water reactors (BWR) and pressurized water reactors (PLWR or LWR), which are both light-water reactor (LWR) designs and are cooled and moderated by water. There also are pressurized heavy-water reactor (PHWR or HWR) designs. 

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). 

All over the world, 432 nuclear power reactors are under operation and more than 36 GW of electricity could be produced as of December 31, 2001. There are several types of reactors such as boiling water reactor (BWR), pressurized water reactor (PWR), Canada deuterium uranium (CANDU), and others. In these reactors, light water is normally used not only as a coolant, but also as a moderator. On the contrary, in CANDU reactors, heavy water is taken. It is widely known that the quality control of coolant water, the so-called water chemistry, is inevitably important for keeping the integrity of the plant. 

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