Patent Number: 
Section: claims

1. A system for installing and operating a control rod blade in a Nordic reactor pressure vessel (RPV) of a nuclear powerplant, the system comprising:a control rod blade (CRB), wherein the CRB extends in an axial direction and includes a neutron absorber section and a single-piece lower fin joined directly below the neutron absorber section, wherein the lower fin includes a bottom terminal edge with a receptor, and wherein the entire control rod blade is shaped and sized to fit between a plurality of fuel bundles in the RPV;a control rod drive system configured for linearly moving the CRB in the axial direction; andan adapter having a single-piece construction, wherein,the single-piece adapter includes a top axial end shaped to directly mate with the receptor,the single-piece adapter includes a bottom axial end with a fastener that removably connects directly to the control rod drive,the single-piece adapter has an axial length spanning an entire distance between the receptor in the bottom terminal edge of the CRB and at least the top of the control rod drive, andthe single-piece adapter is configured to connect the single-piece lower fin of the CRB and the control rod drive system via only the single-piece adapter. 2. The system of claim 1, wherein the CRB is cruciform and is configured to fit between the fuel bundles in to perpendicular transverse directions. 3. The system of claim 1, wherein the top axial end of the single-piece adapter is configured to be welded with the receptor in the bottom terminal edge of the control rod blade, and wherein the adapter supports a weight of the control rod blade as the control rod blade is moved in a linear motion. 4. The system of claim 3, wherein the single-piece adapter is cylindrical. 5. The system of claim 4, wherein the axial length of the single-piece adapter is about 95 inches to about 105 inches. 6. The system of claim 5, wherein the single-piece adapter has an outside cylindrical diameter of about 2.5 inches to about 3.5 inches. 7. A method of using the system of claim 1, the method comprising:lowering the CRB through the fuel bundles so that the receptor of the bottom terminal edge of the single-piece lower fin of the CRB is accessible below the fuel bundles;connecting the single-piece adaptor to the CRB by mating the top axial end of the single-piece adaptor directly to the receptor of the bottom terminal edge of the single-piece lower fin of the CRB; andremovably attaching the bottom axial end of the single-piece adaptor directly to the control rod drive system. 8. The method of claim 7, wherein the mating includes welding the top axial end of the single-piece adaptor directly to the receptor of the bottom terminal edge of the single-piece lower fin of the CRB. 9. The method of claim 7, wherein the removably attaching includes fastening the bottom axial end of the single-piece adaptor directly to the control rod drive system. 10. The method of claim 7, further comprising:driving the control rod drive system to move the CRB in the axial direction.