Pressure MZFR reactor

HWRs of the pressure vessel type have been designed and constructed in Sweden, Germany, and Argentina. The main references of this line are the Agesta reactor in Sweden (shutdown), the MZFR reactor in Germany, and the Atucha-1 and Atucha-2 reactors in Argentina. 

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... 

The experience gained with the MZFR and the most remarkable success of H2O pressurized water reactors provided a strong Inducement to develop the MZFR concept of a natural uranium fuelled D2O-PWR up to an economic size. This had been achieved when we tendered for the 320 MW Atucha unit in the Argentine last year. 

Arranging the control rod drives above the reactor vessel offers important technical advantages. The design principle, which proved successful with the MZFR, has therefore been retained without alteration. Twenty-nine control and shutdown rods are inserted at an angle into the pressure vessel from its periphery. It has been verified by calculations that undamped local power oscillations cannot occur in the core of the size of a 300 MW reactor, so that the reactor can be kept under control by two rods when operating at full power. 

The core dimensions characteristic of natural uranium reactors require pressure vessels of large diameter. Six years ago, when the design of the MZFR vessel was established, Its parameters corresponded to the production capabilities at that time. Those limitations have meanwhile been transgressed and are no longer valid. The Steel vessel for the Atucha power plant corresponds to an electrical output of... 

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