PURPOSE: To provide a spring and spacer assembly for holding the fuel rod of a reactor fuel assembly at suitable upright position.

CONSTITUTION: Springs 92a, 92b, 92c have legs 106, and two loops 116, 118 at the ends of the legs 106, respectively. The loops are engaged with the lugs formed at the ferrule of a spacer. The loops 116, 118 have recesses 122, 124 in contact with the lugs 132, 134 of the ferrule 136. The recess or protrusion is provided at the central leg 106 to press a fuel rod to a stop in contact with fuel rods 82a, 82b, 82c. Spring load is transmitted to the lugs 132, 134 via the recesses 122, 124 of the loops 116, 118. The spring is rotated at the recess as a center at the time of deflecting to enhance the flexibility of the spring. Since the flexibility of the spring is high, the spring can be used together with the fuel assembly of narrow interval of the rods. With the structure, the spring of small mass and surface area can be provided to reduce the disturbance of the flow of neutron absorption.