Spent nuclear fuel storage rack system with reactivity controls

A neutron absorber insert for a fuel rack used for wet storage of nuclear fuel, the neutron absorber insert comprising:

• a neutron absorber plate including a top end and a bottom end, the neutron absorber plate configured for insertion in a fuel storage cell of the fuel rack which is configured for receiving a nuclear fuel assembly therein;
• the neutron absorber plate comprising boron and a rectilinear attachment plate coupled to a lower end of the neutron absorber plate, the attachment plate comprising a central aperture configured to receive a raised support ring at least partially therein disposed at a bottom of the fuel storage cell;
• a plurality of resiliently deformable radial locking protrusions disposed on the attachment plate which project radially inwards into the central aperture of the attachment plate to frictionally engage an outward facing annular side surface of the support ring;
• the support ring defining a central flow hole extending completely through the support ring and circumscribed by an annular angled seating surface which is configured to engage a complementary configured angled conical lower end of the fuel assembly;
• and
• a plurality of resiliently deformable locking protrusions disposed on the bottom end of the neutron absorber plate, the locking protrusions projecting radially inwards into the central aperture of the attachment plate and operable to frictionally engage the raised fuel assembly support ring disposed on the fuel rack at a bottom of the fuel storage cell.

A fuel rack with reactivity control for storing spent nuclear fuel, the fuel rack comprising:

• a baseplate comprising at least one flow hole;
• a cellular body extending from the baseplate and comprising a plurality of cell walls, the cell walls defining a plurality of open cells each configured to store a nuclear fuel assembly therein;
• a support ring disposed at a bottom of at least one of the open cells and affixed to the baseplate, the support ring comprising a flow hole aligned with the at least one flow hole of the baseplate;
• and
• a neutron absorber insert disposed in the at least one of the open cells, the neutron absorber insert comprising a top end and a bottom end configured to frictionally engage the support ring in the at least one of the open cells to secure the neutron absorber insert therein.