Heavy water reactors vessel

PRESSURIZED HEAVY WATER REACTORS (VESSEL TYPE)... 

The PHWR 300 of KWU is a pressurized heavy water reactor of the pressure vessel type with the following main characteristics ... 

The variety of heavy water reactors which exist may be classified on the basis of coolant (D2O, H2O, organic liquid, or CO2 gas) and of basic design (pressure tube or pressure vessel). The subdivisions of reactor types constructed to date, with examples of each, are illustrated in Fig. 10.1. 

Fig. 10.2. Comparison of pressure tube and pressure vessel designs of heavy water reactor (courtesy of Atomic Energy of Canada Limited).

The heavy water pressure vessel reactor MZFR, the prototype of the plant ordered for the Argentine, has been on power since March, 1966 (ref. 1). The reactor went critical in September, 1965 and commenced power production 6 months later. Its gross electrical output is... 

Fig. 1 Pressure vessels for heavy water reactors with natural uranium...

THE EVOLUTION OF THE HEAVY WATER PRESSURE VESSEL REACTORS... 

A. STUGER R.A. and FREI G. The primary cooling system of an Integrated heavy water reactor with concrete pressure vessel. EN-l/18 presented at Symposium on the Technology of Integrated Primary Circuits for Power Reactors, Paris, 20-2 2nd May,... 

Performance of Insulation for prestressed concrete pressure vessels for boiling heavy water reactors. Nuclear Engineering and Design 1, 1967. 

The HFBR at Brookhaven National Laboratory is a heavy water moderated and cooled reactor designed to provide an intense beam of neutrons to the experimental area. In addition using thimbles i oiitaincd within the vessel, it provides isotopic production, neutron activation analysis, ami muiemi irradiations. It began operation in 1965 at a power of 40 MW to be upgraded to 60 MW m 19S2. 

To slow down and control the rate of reaction, a moderator is also required. Typically, the moderator is boric acid, graphite, or heavy water (D20) and is present in the high-purity water, which also serves as a primary coolant for the fuel and the reactor vessel. The tremendous heat generated by nuclear fission is transferred to this closed-loop coolant, which is contained within a reactor primary-coolant circulation system. The high-purity water coolant also contains a suitable pH buffer such as lithium hydroxide, which has the additional effect of limiting the corrosion of fuel-cladding and other components. 

Two-circuit heat removal system with steam-water cycle of supercritical parameters is very difficult for realization, because super high pressure steam generator ( 250 atm) should be located inside the reactor vessel (BREST concept), and there is a real possibility of the core blockage by the products of water and heavy coolant interaction resulting in the core melt- down. Such incident took place in the propulsion reactor cooled by PbBi [7.11],... 

Pressure vessel heavy water-cooled, HWM reactor... 

The reactor core is approximately cylindrical and consists of vertical fuel assemblies located in the same number of fuel channels. The coolant channels are arranged on a triangular lattice pitch and penetrate the top and bottom plenums located inside a cylindrical pressure vessel containing the moderator heavy water at a similar pressure to the HTS. 

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