End fitting retainer for nuclear fuel assembly

Claim 2

In a nuclear reactor fuel assembly having a plurality of upstanding fuel rods, an end fitting extending across the tops of said fuel rods to retain the same in position, and support means holding said end fitting in position, the improvement comprising: an opening through said end fitting in vertical alignment with said support means; said support means having a neck portion extending upwardly in said opening; a circumferential groove around said neck portion; and a radially flexible resilient annular member in said groove having its radially inner portion in said groove and an outer portion overlying and engaging an upwardly facing surface portion of said end fitting, said resilient member being flexibly distortable to a diameter to substantially disengage from one of said end fitting and support means for removal of said end fitting from said support means.

Claim 3

A nuclear reactor fuel assembly defined in claim 1 wherein said annular member comprises a split ring of spring metal having upper and lower end surfaces slidably engaging the axial ends of said groove.

Claim 4

A nuclear reactor fuel assembly as defined in claim 2 wherein said lower end surfaces comprises the lower end of a portion of said ring extending within said opening.

Claim 5

A nuclear reactor fuel assembly as defined in claim 2 wherein at least the upper portion of said annular member extends above said end fitting and is of generally conical, upwardly tapering, shape whereby a sleeve member may be forced downwardly over said annular member and cam the same inwardly into said groove.

Claim 6

A nuclear reactor fuel assembly as defined in claim 4 wherein the lower end of said opening is chamfered whereby said end fitting, when separated from said support means, may be lowered over said neck portion to cause said chamfered end to cam said annular member into said groove for passage through said opening and subsequent expansion into retaining engagement with said upper surface portion of said end fitting.

Claim 7

A nuclear reactor fuel assembly as defined in claim 1 wherein said support means is provided with an upwardly facing shoulder below and engageable with said end fitting to limit downward movement Thereof on said neck portion.

Claim 8

A nuclear reactor fuel assembly as defined in claim 2 wherein said ring normally expands to an outer diameter greater than that of said neck portion and is contractible to an outer diameter no greater than that of said neck portion.

Claim 9

A nuclear reactor fuel assembly as defined in claim 2 wherein said ring normally contracts to an inner diameter less than and an outer diameter greater than said neck portion, said upwardly facing surface portion of said end fitting being defined by a side of an internal groove between the ends of said opening, the depth of said internal groove being sufficient for said ring to be radially expanded therein to an internal diameter at least as large as the diameter of said neck portion.

Claim 10

A nuclear reactor fuel assembly as defined in claim 8 wherein at least said neck portion is provided with passageway, from its upper end, communicating with the groove in said neck portion whereby to render said ring accessible for applying a radial expanding force thereto.

Claim 11

In a nuclear reactor fuel assembly having a plurality of upstanding fuel rods, support means, an end fitting on said support means and extending across the tops of said fuel rods, and cooperating means between said end fitting and support means for holding said end fitting seated on said support means, the improvement comprising: resiliently movable means on one of said end fitting and support means, biased to engage the other to hold said end fitting seated on said support means, said resiliently movable means being aceessible from above said end fitting forcible flexure to a release position to permit upward removal of said end fitting from said support means; and cooperating camming surfaces on said resiliently movable means and said other one of said end fitting and support means whereby said end fitting may be lowered toward said supoort means and thereby cause said surfaces to move said resiliently movable means to release position until said end fitting substantially seats on said support means.

Claim 12

In a nuclear reactor fuel assembly having a plurality of upstanding fuel rods, support means, an end fitting on said support means and extending across the tops of said fuel rods, and cooperating means between said end fitting and support means for holding said end fitting seated on said support means, the improvement comprising: resiliently movable means on one of said end fitting and support means, biased to engage the other to hold said end fitting seated on said support means, said resiliently movable means being aceessible from above said end fitting forcible flexure to a release position to permit upward removal of said end fitting from said support means; and cooperating camming surfaces on said resiliently movable means and said other one of said end fitting and support means whereby said end fitting may be lowered toward said supoort means and thereby cause said surfaces to move said resiliently movable means to release position until said end fitting substantially seats on said support means.