A PCPV with elastic hot liner

A hot liner in direct contact with the coolant has been developed to improve the operational safety of prestressed concrete pressure vessels (PCPV). The liner is accessible for inspection, leak detection and repair, leading to an increased availability of the plant. High strength liner materials combined with a simple temperature control system to adjust the vessel wall temperature in relation to the liner temperature keep the liner in the elastic compression eliminating the danger of plastification. The liner is also an effective control of possible leakages. Comparisons with existing vessels have been made and the experiments to verify the concept are outlined. The PCPV concept can be applied to gas cooled thermal and fast reactors and light and heavy water-cooled reactors. Many shapes are possible including mono-cavern, multicavern and satellite designs and the feasibility studies which have been carried out are discussed. (U.K.)