DE3416620

1. Underwater crushing unit for activated or contaminated components from the core of nuclear reactors such as poison strips, in core measuring lances, absorber rods, water guide tanks, consisting substantially of a pressing and cutting unit which is fixed on a frame, wherein the pressing and cutting unit is made up of a part (1) which is fixed directly on the frame (8) and consists of a guide funnel member (7), a pressing jaw (10) and a cutting blade (12) and also of a part (2) which can be moved via a driveable hydraulic cylinder (19) and consists of a guide funnel member (6) and a pressing jaw (9) and also of a cutting blade (11) which can be moved separately via a driveable cylinder (20), characterised in that rollers (17, 18) with parallel shafts which are mounted opposite one another in guides (3) are located both in the directly fixed part (1) and in the moving part (2) between the respective guide funnel member (6, 7) and the respective pressing jaw (9, 10), wherein the roller (18) allocated to the directly fixed part (1) is connected via a driveable hydraulic cylinder (24), a piston rod (30) and a ratchet (25) with return stop to the frame (8) and the two rollers (17, 18) are connected by means of pinions (31, 32) fixed on them via a chain (27), the chain (27) additionally being guided via a compensating wheel (26) and a chain wheel clamping pinion (28) which is also fixed on the frame (8) by means of a chain tension spring (29).