Protection of the containment of the twin BWR KRB II plant against overpressure failure during severe accidents Original Research Article

The 2 × 1310 MWel plant KRB II as the newest design BWR plant in Germany (with prestressed concrete containment) had to go, with respect to the other BWRs, slightly different ways in solving the problem of containment overpressure protection during severe accidents. The basic concept of the plant and the special boundary conditions of the twin unit concept required modified solutions for the realized containment filtered venting system and the measures against energy release due to HZ reactions. The paper reports on the objectives, design, arrangement and installation of the equipment provided hereto. Special emphasis is layed upon the operation experience with the equipment installed. Furthermore, an outlook is given on possible complementary installations such as HZ-igniters and -recombiners and containment atmosphere monitoring and sampling.