Abstract: A modified polyolefin resin having an intended adhesion strength to various substrates even when graft modification may be carried out by using an ?,?-unsaturated carboxylic acid derivative having a cyclic structure. The modified polyolefin resin may be a modified product of a polyolefin resin and satisfies conditions (A) to (C): condition (A)—a modifying component includes an ?,?-unsaturated carboxylic acid derivative having a cyclic structure; condition (B)—a ring-opening degree expressed by formula (1) is 40 or more; and condition (C)—the polyolefin resin includes an ethylene structural unit, ring-opening degree=modification degree K×ring-opening rate R??(1) wherein, in the formula (1), the modification degree K is a grafting weight (wt. %) of the ?,?-unsaturated carboxylic acid derivative, and the ring-opening rate R is a ring-opening rate (%) of the cyclic structure in the ?,?-unsaturated carboxylic acid derivative.

Abstract: A method of assembling a fuel assembly is presented so as to reduce radiation exposure to the assembly workers and to simplify the assembly procedure. Sleeves are pre-attached to an upper nozzle, and the guide pipes are inserted into respective grid cells through the sleeves of the upper nozzle and through the sleeves of the grids. The guide pipes are fixed in place to the sleeves of the upper nozzle and of the grids by bulging. There is no welding step necessary to join any of the assembly components while the assembly is in a semi-assembled condition. Therefore, the method is simple and efficient, and reduces the risk of radiation exposure to the assembly workers.