公开(公告)号：US3904048A

公开(公告)日：1975-09-09

申请号：US18217171

申请日：1971-09-20

Applicant: ASEA AB

Inventor： VAN SANTEN AART ,  ELOFSSON KJELL

IPC: G21C3/326 ,  G21C3/335 ,  G21C19/10 ,  G21C19/20

CPC classification number: G21C19/10 ,  G21C3/326 ,  G21C3/335 ,  G21C19/205 ,  Y02E30/38

Abstract: A nuclear reactor formed of fuel assemblies each including a plurality of parallel fuel rods arranged in a predetermined fuel rod lattice, which rods are freely extractable and insertable at one end of the fuel assembly, is refueled by extracting from one of the fuel assemblies a number of fuel rods substantially less than the total number of fuel rods and replacing these by inserting new fuel rods into the vacated positions. This is done for a majority of fuel assemblies of the reactor. At the next refueling operation different fuel rods from those previously replaced are removed and replaced. The removal and return of the rods is produced by a tool having a plurality of gripping members capable of engaging shoulders beneath heads formed on the upper ends of the fuel rods. This may be accomplished by providing a tool having a number of gripping members attached to the tool body corresponding to the lattice positions of the fuel rods to be extracted, having gripping members which can be pushed together to grip beneath shoulders on the upper ends of the fuel rods.