FENCING STATION FOR A CORE POWER PLANT AND A PLENUM SPRING DESIGNED FOR PROVIDING IN SUCH A FIRE STATION

摘要

The present invention relates to a fuel rod for a nuclear plant and a plenum spring arranged to be provided in a fuel rod. The fuel rod ( 1 ) comprises a cladding tube ( 2 ) sealed at its ends by end plugs ( 3, 4 ), a plurality of fuel pellets ( 5 ) stacked on each other inside the cladding tube ( 2 ) such that they form a column of pellets and said plenum spring ( 6 ) arranged to hold with a spring force the column of pellets against the lower second end of the cladding tube ( 2 ) during operation. The plenum spring ( 6 ) comprises a first length variable part ( 8 ) which abuts the uppermost located fuel pellet ( 5 ) in the column of pellets with an end portion ( 9 ), a second part ( 10 ) which allows engagement of the plenum spring ( 6 ) against an inner surface of the cladding tube ( 2 ) by a radially outwardly directed pressure and a third part ( 11 ) which allows releasing of the second part ( 10 ) of the plenum spring ( 6 ) in the cladding tube ( 2 ) during operation of the nuclear plant.