US 4,229,255 A · Method and apparatus for positioning and ejecting fuel element bundles in and from a downstream end of a horizontally extending fuel channel

Abstract

A fuel bundle positioning and ejecting apparatus comprising two piston members, one slidable along a stem on the other piston member, and a compression spring urging the pistons apart, is secured in a horizontally extending fuel channel upstream of the coolant flow therealong. The downstream one of the piston members has a shield plug attached thereto and the piston members are urged together in a fuel channel with he compression spring compressed, by a series of fuel element bundles along the fuel channel. When the downstream end of the fuel channel is opened using a fuelling machine, with pressurized coolant therein and continued circulation of coolant along the fuel channel, the compression spring expands causing the piston members to become entrained in the coolant and urge the fuel element bundles out of the fuel channel and into the fuelling machine. The positioning and ejecting device avoids the trailing fuel element bundle from becoming trapped in a downstream end of the fuel channel through which there is no coolant flow. The apparatus includes variable flow restriction means to prevent the flow in the channel from increasing beyond acceptable limits to the fuel since the flow inherently tends to increase as fuel bundles are being removed and the flow resistance in the channel is reduced.

Claims6

Dependent claims

A nuclear fuel bundle assembly positioning and ejecting apparatus using pressurized coolant flow entrainment to eject fuel bundles from a downstream end of a horizontally extending fuel channel, beyond the coolant flow therein, comprising:

(a) a first piston member slidable along the bore of the fuel channel,
(b) a stem integral with the first piston member and extending therefrom in a sliding direction thereof,
(c) a second piston member slidable along the bore of the fuel channel and slidably located on the stem,
(d) a compression spring between the first and second piston members for compression therebetween, and whereby,
(e) with the positioning and ejecting apparatus in a portion of the fuel channel which is upstream of pressurized coolant flow therethrough, and with the compression spring held compressed at the upstream end by the fuel channel and at the downstream end by a series of fuel bundles, in a shielded portion of the fuel channel, opening the downstream end of the fuel channel with a fuelling machine connected thereto will cause the compression spring to move the piston members apart and the positioning and ejecting apparatus will become entrained in the coolant flow and eject the fuel bundles from the downstream end of the fuel channel into the fuelling machine.

2 more elements

A method of positioning and ejecting nuclear fuel bundles in and from a horizontally extending nuclear fuel channel using pressurized coolant flow entrainment to eject the fuel bundles beyond the downstream end of the coolant flow therein, wherein:

(a) the fuel channel is loaded with a series of fuel element bundles, a downstream shield plug and a positioning and ejecting apparatus in the upstream end of the fuel channel, the positioning and ejecting device comprising:
(i) a first piston and shielding member slidable along the bore of the fuel channel,
(ii) a stem integral with th first piston member and extending therefrom in a sliding direction thereof,
(iii) a second piston member slidable along the bore of the fuel channel and slidably located on the stem,
(iv) a compression spring between the first and second piston members for compression therebetween, and
(b) an upstream one of the piston members of the positioning and ejecting apparatus is engaged with the fuel channel to locate the ejecting device in a portion of the fuel channel which is upstream of pressurized coolant flow therethrough, and then urging the first piston member upstream by means of the series of fuel element bundles so that the compression spring is compressed between the first and second piston members with the series of fuel bundles located in a shielded portion of the fuel channel and held therein by the downstream shield plug and a closure plug which is secured to the downstream end of the fuel channel, whereby
(c) the fuel element bundles may be ejected from the fuel channel by removing the closure plug from the downstream end of the fuel channel with a fuelling machine attached thereto and pressurized coolant circulating through the fuel channel, so that;
(d) the compression spring of the positioning and ejecting apparatus moves the piston members apart and entrains the loading and ejecting apparatus in the coolant flow, and
(e) the entrainment of the positioning and ejecting apparatus in the coolant flow causes the downstream shield plug and the fuel element bundles to be ejected from the downstream end of the fuel channel into the fuelling machine.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for positioning and ejecting fuel element bundles in and from a downstream end of a horizontally extending fuel channel

Life of this patent

Method and apparatus for positioning and ejecting fuel element bundles in and from a downstream end of a horizontally extending fuel channel

Life of this patent

Abstract

Claims6