Nuclear plant

Abstract

This invention relates to a nuclear plant having a reactor vessel and a fluid circuit including flow path defining means, defining a flow path for circulating a reactor coolant fluid from and to the reactor vessel. The nuclear plant includes a particle collection zone defined along at least part of the length of the flow path, and particle deflection means arranged in particle deflecting relationship with the flow path to deflect particles from a fluid stream in the flow path into or toward the particle collection zone.

1 . A nuclear plant including a reactor vessel, a fluid circuit which includes flow path defining means defining a flow path for circulating a reactor coolant fluid from and to the reactor vessel, a particle collection zone defined along at least part of the length of the flow path, and particle deflection means arranged in particle deflecting relationship with the flow path to deflect charged particles from a reactor coolant fluid stream in the flow path into or towards the particle collection zone, characterized in that (i) the particle deflection means is provided by a magnetic deflection arrangement for generating a magnetic field in the flow path; and (ii) the particle collection zone comprises a deposition material in which the deflected charged particles can be embedded. 
     
     
         2 . A nuclear plant as claimed in  claim 1 , which includes particle ionisation means disposed in the flow path upstream of the particle deflection means for ionising particles in the fluid stream. 
     
     
         3 . A nuclear plant as claimed in  claim 2 , in which the particle ionisation means includes at least one ioniser selected from the group consisting of a neutron source, photon source, heat source and an electromagnetic radiation source. 
     
     
         4 . A nuclear plant as claimed in  claim 1 , in which the magnetic deflection arrangement is adapted to generate a magnetic field of generally constant magnetic flux across a cross-sectional area transverse to a direction of flow of the fluid stream. 
     
     
         5 . A nuclear plant as claimed in  claim 1 , in which the magnetic deflection arrangement includes at least two pairs of opposed magnets arranged adjacent the flow path defining means, the magnets of a pair having inwardly disposed poles of opposite polarity and the pairs being arranged so as to have angularly off-set poles of like polarity. 
     
     
         6 . A nuclear plant as claimed in  claim 5 , in which the poles of like polarity of the pairs of opposed magnets are angularly off-set by between 0 degrees and 90 degrees. 
     
     
         7 . A nuclear plant as claimed in  claim 6 , in which the poles of like polarity of the pairs of opposed magnets are off-set by 45 degrees. 
     
     
         8 . A nuclear plant as claimed in  claim 6 , in which the poles of like polarity of the pairs of opposed magnets are off-set by 90 degrees. 
     
     
         9 . A nuclear plant as claimed in  claim 1 , in which the magnetic deflection arrangement includes at least one toroidal magnet arranged around the flow path defining means. 
     
     
         10 . A nuclear plant as claimed in  claim 1 , in which the magnetic deflection arrangement includes at least one permanent magnet. 
     
     
         11 . A nuclear plant as claimed in  claim 1 , in which the magnetic deflection arrangement includes at least one electromagnet. 
     
     
         12 . A nuclear plant as claimed in  claim 1 , in which the deposition material forms part of at least one particle deposition bed defined on an internal surface of the flow path defining means. 
     
     
         13 . A nuclear plant as claimed in  claim 12 , in which at least part of a wall of the flow path defining means provides the at least one particle deposition bed. 
     
     
         14 . A nuclear plant as claimed in  claim 12 , in which the at least one particle deposition bed is provided by a deposition lining on an internal surface of the flow path defining means. 
     
     
         15 . A nuclear plant as claimed in  claim 12 , in which the deposition bed comprises a plurality of layers of particle diffusion-resistant material. 
     
     
         16 . A nuclear plant as claimed in  claim 15 , in which at least one layer of the deposition bed is comprised of a fluid material. 
     
     
         17 . A nuclear plant as claimed in  claim 16 , which includes fluid material circulation means for circulating the fluid material such that fluid material can be removed from and replaced to the deposition bed. 
     
     
         18 . A nuclear plant as claimed in  claim 17 , in which the fluid circulation means includes secondary particle removal means for removing particles collected in the fluid material therefrom, after removal of the fluid material from and prior to replacement of the fluid material to the deposition bed. 
     
     
         19 . A method of removing charged particles from a coolant fluid in a nuclear plant having a reactor vessel and a fluid circuit which includes flow path defining means defining a flow path for circulating the coolant fluid from and to the reactor vessel, the method including:
 directing a stream of the coolant fluid and which contains charged particles along the flow path;   applying a magnetic field across the flow path such that charged particles are deflected in the flow path; and   embedding the deflected charged particles in a deposition material.   
     
     
         20 . A method as claimed in  claim 19 , wherein the deposition material forms part of at least one particle deposition bed defined on an internal surface of the flow path defining means. 
     
     
         21 . A method as claimed in  claim 20 , wherein the deposition bed comprises a plurality of layers of particle diffusion-resistant material. 
     
     
         22 . A method as claimed in  claim 19 , which includes, where the deposition material is a fluid material, removing and replacing fluid material in which particles have been collected. 
     
     
         23 . A method as claimed in  claim 22 , which includes circulating the fluid material through secondary particle removal means to remove particles collected in the fluid material from the fluid material. 
     
     
         24 . A method as claimed in  claim 19 , in which applying the magnetic field across the flow path includes arranging at least one permanent magnet in magnetic deflecting relationship with the flow path. 
     
     
         25 . A method as claimed in  claim 19 , wherein a magnetic field of generally constant magnetic flux across a cross-sectional area transverse to a direction of flow of fluid stream, is generated. 
     
     
         26 . A method as claimed in  claim 19 , in which applying the magnetic field across the flow path includes arranging at least one electromagnet in magnetic deflecting relationship with the flow path. 
     
     
         27 . A method as claimed in  claim 26 , in which applying the magnetic field includes pulsating the magnetic field.