Production of neutron shielding material

Claim 1

The method of making rigid neutron absorbing sheet material which comprises forming an open-ended rectangular metal box by continuously welding together the edges of rectangular top and bottom forming plates, side forming strips, and one end forming strip, mixing together finely divided neutron absorbing boron compound and a finely divided metal powder to produce a substantially uniformly dispersed mixture thereof, positioning the box with its open end up, completely filling the box with material from the uniform mixture, jarring the filled box repeatedly to cause the finely divided mixture to settle to eliminate voids or air pockets in the box, adding material from the mixture as required to ensure that the box is filled, applying the other end forming strip to the box in solid abutment against the powdered material and providing a continuous weld around its edges to the adjacent end edges of said top and bottom forming plates and side forming strips to produce a composite ingot suitable for rolling, soaking the ingot to bring it to an elevated temperature of 800°-850° F., and hot rolling the ingot at substantially the aforesaid temperature in repeated passes to reduce its thickness to form a thin rigid neutron absorbing sheet material in which the particles of finely divided neutron absorbing material and metal powder are molecularly bonded together and to the inner surfaces of the thin metal outer plies produced from the top and bottom forming plates.

Claim 2

The method of making rigid neutron absorbing sheet material which comprises forming an open-ended rectangular metal box by continuously welding together the edges of rectangular top and bottom forming plates, side forming strips, and one end forming strip, mixing together finely divided neutron absorbing boron compound and a finely divided metal powder to produce a substantially uniformly dispersed mixture thereof, positioning the box with its open end up, completely filling the box with material from the uniform mixture, jarring the filled box repeatedly to cause the finely divided mixture to settle to eliminate voids or air pockets in the box, adding material from the mixture as required to ensure that the box is filled, applying the other end forming strip to the box in solid abutment against the powdered material and providing a continuous weld around its edges to the adjacent end edges of said top and bottom forming plates and side forming strips to produce a composite ingot suitable for rolling, soaking the ingot to bring it to an elevated temperature of 800°-850° F., and hot rolling the ingot at substantially the aforesaid temperature in repeated passes to reduce its thickness to form a thin rigid neutron absorbing sheet material in which the particles of finely divided neutron absorbing material and metal powder are molecularly bonded together and to the inner surfaces of the thin metal outer plies produced from the top and bottom forming plates.