Control Blades for the High Flux Beam Reactor

The High Flux Beam Reactor at Brookhaven is controlled by neutron absorbing blades that contain 30 vol% Eu₂O₃ or Dy₂O₃ dispersed in stainless steel. The europium oxide is used in areas of high burn-up. The rare-earth compacts are rolled into 0.132-in.-thick plates that are clad with ≥0.20-in. stainless steel. Four such plates are electron beam welded to form an angle-shaped blade with a central cooling channel. After ∼11 000 MWd of service and exposure to almost 2 × 10²¹ n cm⁻², the blades continue to perform satisfactorily in this D₂O-cooled and -moderated research reactor.