초록 ▼

A reconstitutable fuel assembly includes an improved attaching structure which has a plurality of coupling sleeves interfitting the upper hold-down plate, lower adapter plate and a plurality of hold-down springs of the top nozzle of the assembly. The coupling sleeves insert over a plurality of exten

A reconstitutable fuel assembly includes an improved attaching structure which has a plurality of coupling sleeves interfitting the upper hold-down plate, lower adapter plate and a plurality of hold-down springs of the top nozzle of the assembly. The coupling sleeves insert over a plurality of extensions extending upwardly from the main bodies of the guide thimbles. The sleeves rest on annular ledges formed on the bottom portions of the respective extensions. A removable cap is attached to the top portion of each of the thimbles extensions and applied to the upper portion of each of the coupling sleeves to releasably lock the coupling sleeves on the guide thimble extensions. In view that the coupling sleeves are fixed to the adapter plate at their lower portions, the sleeves and hold-down plate, adapter plate and hold-down springs disposed between the plates and encircling individual sleeves can be removed together from the fuel assembly as a unitary subassembly upon removal of the removable caps.

대표청구항 ▼

In a reconstitutable fuel assembly having at least one control rod guide thimble and a top nozzle, said guide thimble including an upper extension, said top nozzle including at least one hold-down spring, an upper hold-down plate and a lower adapter plate, an improved attaching structure removably m

In a reconstitutable fuel assembly having at least one control rod guide thimble and a top nozzle, said guide thimble including an upper extension, said top nozzle including at least one hold-down spring, an upper hold-down plate and a lower adapter plate, an improved attaching structure removably mounting said top nozzle as a unitary subassembly on said guide thimble, said attaching structure comprising: (a) a coupling member interfitting said lower adapter plate, said upper hold-down plate and said hold-down spring disposed between said plates so as to capture and retain said plates and spring together as a unitary subassembly in which said upper plate is slidably movable along said coupling member relative to said lower plate with said spring biasing said upper plate away from said lower plate, said coupling member having spaced apart upper and lower portions with a central passageway extending therebetween for slidably receiving said upper extension of said guide thimble therein in a nonattached relationship in which said coupling member is slidably movable relative to said guide thimble extension for respectively inserting and removing said coupling member on and from said guide thimble extension; (b) means on said upper extension of said guide thimble supporting said coupling member at its lower portion so as to limit downward movement of said coupling member relative to said guide thimble extension and thereby insertion of said coupling member thereon without limiting upward movement of said coupling member relative to said guide thimble extension and thereby removal of said coupling member therefrom; and (c) a detachable member releasably applied to said upper portion of said coupling member and disengagably engaged with said upper extension of said guide thimble so as to removably lock said coupling member to said guide thimble extension such that removal of said detachable member from both said coupling member and said guide thimble extension is required before said coupling member and said upper hold-down plate, said hold-down spring and said lower adapter plate retained thereon can be removed therewith as a unitary subassembly from said upper extension of said guide thimble.