Fuel assembly hold-up device

Claim 1

In a nuclear reactor core, means defining lower core support structure; means defining upper core alignment structure; a plurality of fuel assemblies vertically disposed between said lower core support structure and said upper core alignment structure, each of said assemblies comprising an upper end fitting, a lower end fitting, structural means attached to each of said end fittings and supporting said fittings in parallel spaced relationship, a plurality of elongated fuel elements disposed in a generally parallel array, and support structures connected to said structural means and receiving therein said fuel elements to maintain them in a vertically extending position between said end fittings; means associated with said upper core alignment structure and said upper end fittings for laterally restraining each of said fuel assemblies while allowing limited axial movement thereof: a plurality of alignment posts affixed to each of said lower end fittings and extending downwardly therefrom; a post engaging means, associated with each of said alignment posts, affixed to and extending upwardly from said lower core support structure for slidably receiving and laterally restraining said alignment posts, said post engaging means including a spring containment section having spring retaining means at its lower end and means for transmitting downward force on said spring retaining means to said lower core support structure; and coil spring means in partial compression disposed within said spring receiving section, reacting downwardly against said lower core support structure and reacting upwardly through said lower end fittings to urge said fuel assemblies in engagement with said upper core alignment structure.