RADIOACTIVE SUBSTANCE STORAGE CONTAINER MANUFACTURING METHOD, AND RADIOACTIVE SUBSTANCE STORAGE CONTAINER

To provide a radioactive substance storage container manufacturing method that can make a streaming pass possible upon assembling a block-like neutron shield body to a radioactive substance storage container small as much as possible.SOLUTION: A radioactive substance storage container manufacturing method comprises: making the temperature of a block-like neutron shield body (10a) lower than an ambient temperature to thereby shrink the neutron shield body (10a) (a cooling step); and installing the shrunk neutron shield body (10a) in a prescribed closed space of at least any of a lateral part, bottom part and lid part of a radioactive substance storage container 100, for example, between adjacent neutron shield bodies (10) on an inner side of an exterior cylinder (7) constituting a container body (1) (a neutron shield body installation step).SELECTED DRAWING: Figure 3 【課題】ブロック状の中性子遮蔽体を放射性物質収納容器に組み込む際に生じ得る隙間を極力小さくすることができる放射性物質収納容器の製造方法を提供すること。【解決手段】ブロック状の中性子遮蔽体（１０ａ）を室温よりも低温の状態にすることで当該中性子遮蔽体（１０ａ）を収縮させる（冷却工程）。収縮した中性子遮蔽体（１０ａ）を、放射性物質収納容器（１００）の側部、底部、および蓋部のうちの少なくともいずれかの所定の閉空間、例えば、容器本体（１）を構成する外筒（７）の内側の隣り合う中性子遮蔽体（１０）の間に設置する（中性子遮蔽体設置工程）。【選択図】図３