Freestanding Liners

1 The demolition and removal of a liner for a PCRV would be considerably simplified if it was possible to have a liner that was largely detached from the concrete vessel. 

2 Free standing liners have been considered In the past. Major problems with this concept are the liner being able to withstand vessel pressure and to accommodate movements across penetrations attached to both the liner and the concrete vessel. The first of these problems could be overcome by pressurising the space between the liner and the vessel concrete. 

3 A PCRV for a commercial nuclear Installation Is fundamentally an Immensely strong and massive structure. It was therefore natural for design engineers to utilise the strength of such a structure to carry the forces on the liner rather than provide an alternative comprehensive support system. 

4 Perhaps the design philosophy for future Installations should be to continue using the PCRV as a means of support for the liner but In some way free the liner to allow Independent movement and subsequent easier dismantling on decommissioning. 

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Preliminary work on the grouted liner concept has identified the likely main problems, typically, construction methods, connecting up cooling pipes and standpipes, assessment of degree of liner anchorage required and so on. It Is recommended that further work on this concept should be carried out to determine whether or not It Is feasible. It Is also recommended that the previous work on the freestanding liner concept be followed up. 

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