Small, fast neutron spectrum nuclear power plant with a long refueling interval

Abstract

Nuclear reactor systems and methods are described having many unique features tailored to address the special conditions and needs of emerging markets. The fast neutron spectrum nuclear reactor system may include a reactor having a reactor tank. A reactor core may be located within the reactor tank. The reactor core may include a fuel column of metal or cermet fuel using liquid sodium as a heat transfer medium. A pump may circulate the liquid sodium through a heat exchanger. The system may include a balance of plant with no nuclear safety function. The reactor may be modular, and may produce approximately 100 MW e .

1 .- 24 . (canceled) 
     
     
         25 . A wedge for a core clamping system, the wedge comprising:
 a first end and a second end wherein the first end has less surface area than the surface area of the second end;   a driveline coupled to a vertical positioning mechanism connected to a reactor deck;   wherein the wedge is vertically adjustable; and   said wedge is configured to loosen a nuclear fuel core assembly for fuel handling.   
     
     
         26 . The wedge of  claim 25 , wherein the wedge is at a lower end of the drive line. 
     
     
         27 . The wedge of  claim 25 , wherein the wedge is inserted into the nuclear fuel core assembly 
     
     
         28 . The wedge of  claim 27 , wherein the wedge is capable of re-insertion to clamp the nuclear core fuel assembly. 
     
     
         29 . The wedge of  claim 25 , wherein the wedge can be inserted to clamp the nuclear core fuel assembly and top load pads outward against a core former ring at a top pad elevation. 
     
     
         30 . The wedge of  claim 29 , wherein the top load pads surround a ducted fuel assembly. 
     
     
         31 . The wedge of  claim 30 , wherein the top load pads surround the ducted fuel assembly above a fuel elevation and below the top load pads. 
     
     
         32 . The wedge of  claim 25 , wherein a vertical position of the wedge is adjusted throughout the nuclear core fuel assembly's life to adjust the core reactivity values. 
     
     
         33 . The wedge of  claim 25 , wherein the vertical position of the wedge is adjusted to loosen the nuclear core fuel assembly. 
     
     
         34 . The wedge of  claim 25 , wherein the vertical position of the wedge is used to adjust nuclear core fuel assembly radial expansion. 
     
     
         35 . The wedge of  claim 25 , wherein the vertical position of the wedge may be in response to increased core coolant temperature. 
     
     
         36 . The wedge of  claim 35 , wherein the wedge's vertical position is moved downward from the wedge's initial vertical position in response to the increased core coolant temperature. 
     
     
         37 . The wedge of  claim 36 , wherein the downward position of the wedge causes increased axial leakage and reduced reactivity of the nuclear core fuel assembly.