Abstract: A neutron absorber member is configured to be inserted into a control rod guide tube of a spent fuel assembly. The neutron absorber member includes a first plate and a second plate. The first plate extends along a longitudinal axis between a first end and a second end. The first plate has a slot formed therethrough at the first end. The slot extends from the first end towards the second end. The second plate is disposed within the slot of the first plate. The first plate and the second plate are arranged to have a cross-sectional shape of a cruciform.

Abstract: A neutron absorber member including a tube having a split extending radially completely through a sidewall of said tube throughout the entire axial length thereof such that the absorber member has a C-shaped geometry formed by the split. The sidewall of the tube is resiliently biased radially outwards and comprised of a metal matrix composite that is configured to absorb neutrons emanation from a spent fuel assembly in a sufficient amount to thereby maintain subcriticality of said spent fuel assembly.

Abstract: A neutron absorber member including a tube having a split extending radially completely through a sidewall of said tube throughout the entire axial length thereof such that the absorber member has a C-shaped geometry formed by the split. The sidewall of the tube is resiliently biased radially outwards and comprised of a metal matrix composite that is configured to absorb neutrons emanation from a spent fuel assembly in a sufficient amount to thereby maintain subcriticality of said spent fuel assembly.

Abstract: Neutron absorber members for a control rod guide tube of a spent fuel assembly are provided as a tube split throughout a length thereof. In further examples, an insertion apparatus for inserting a neutron absorber member into a control rod guide tube of a spent fuel assembly includes an insertion tool base and an insertion tool rod. The insertion tool rod is removably secured within and extending from the insertion tool base according to a position of the control rod guide tube into which the neutron absorber is to be inserted. In further examples, a neutron absorber member retainer for a top nozzle of a spent fuel assembly is provided. The retainer includes a plate configured to inhibit a neutron absorber member inserted in a control rod guide tube from removal.