China
Africa
Explore chapters and articles related to this topic
Nuclear Fission Reactor
Published in C. K. Gupta, Materials in Nuclear Energy Applications, 1989
As the coolant water flows upward through the core, it removes the fission heat from the fuel rods. The system pressure is about 7 MPa at which water boils at 285°C. Of course, not all the water flowing up the core is converted to steam, and the steam water mixture leaving the top of the core contains about 14% by weight of steam. The two-phase core outlet flow passes through a bank of water separators. The separated water is recirculated and the wet steam then enters steam dryers in the upper part of the reactor vessel. In the separators and dryers, most of the water is removed so that saturated steam of at least 99.6% quality leaves the reactor vessel and flows through steam lines to the turbogenerator. The turbine condensate is returned to the reactor as feed water. The water from the dryers and the separated water from the bank of water separators, representing essentially the water which has not been converted into steam in its passage through the core, together with the feed water mix in a pool surrounding the standpipes is recirculated by means of two recirculating pumps. These pumps withdraw water from the annulus between the core shroud and the reactor vessel wall and force it through several jet pumps mounted internally in this region. The water jets draw in additional surrounding water and expel it into the valve at the bottom of the reactor vessel. The water is thus forced to circulate continuously through the core. The core shroud serves to provide a barrier to separate the upward flow through the core from the downward flow in the annulus between the reactor vessel wall and the shroud.
Evaluation of the structural integrity of a BWR core shroud with non-regular locations of circumferential cracks. Part I fracture analysis
Published in Journal of Nuclear Science and Technology, 2021
Pablo Ruiz López, Luis Héctor Hernández Gómez, Yunuén López Grijalba, Alejandra Armenta Molina, Salatiel Pérez Montejo, Juan Alfonso Beltrán Fernández
The core shroud is a reactor internal of a BWR with an important safety function for a nuclear power plant. For life extension or license renewal reasons, its structural integrity was evaluated after 30 and 60 years of operation. Table 6 summarizes the results after thirty years of operation under normal and failure conditions of operation.