The reliability of pressurized water reactor vessels

Abstract

The mechanical integrity of major engineering structures such as pressure vessels, pipelines, nuclear reactors, aircraft and offshore oil platforms is a matter of great practical importance for both economic and safety reasons. In practice this integrity must be assured by careful attention to many aspects of design, materials, manufacture, inspection, modes of operation and so forth. In the present chapter we are concerned with the pressure vessels of nuclear light-water reactors, particularly those of pressurized water reactors (P.W.R.’s). For an excellent account of light-water reactors (L.W.R.’s) in general we refer the reader to Collier (1983), where it is shown that the integrity of the reactor vessel is one of the principal safety considerations with this type of reactor. In Fig. 6.1 we show the reactor vessel of a typical P.W.R.; in (a) as containing the reactor core and associated equipment, in (b) in relation to the primary coolant circuit including the steam generators which supply the turbines (‘secondary circuit’) and in (c) in relation to the containment. The diversity of the considerations relating to the integrity of such pressure vessels is well illustrated by the reviews and assessments made by a study group in the U.K. chaired by Dr. (now Lord) Walter Marshall (1976, 1982).