1. Structural materials and water chemistries in BWRs

1.1 BWR vs. PWR systems

The controlled fission reaction of the ²³⁵ U into two smaller nuclei in the fuel elements in the reactor core of LWRs produces ~ 200 MeV heat per fission event. This heat is used to produce steam that drives a steam turbine connected to a generator that produces electricity. The steam cycle of LWRs is thus similar as in a conventional coal-fired thermal power plant. The peculiarities of the LWRs are mainly related to the nuclear parts and the radioactivity and various radiation effects as well as to the related specific nuclear risks and necessary protection and precautions measures. There are two different basic types of LWRs, PWRs and BWRs.

PWR reactors are closed systems that operate...