Sputtering process burnable poison coating

A method for coating the inside surface of a zircaloy fuel rod cladding tube with burnable poison material, comprising:

• supporting the cladding tube in a fixture;
• supporting a source tube of burnable poison material coaxially within the cladding tube, thereby defining a cylindrical annular space between the tubes;
• evacuating the annular space and backfilling the annular space with an inert working gas to a pressure sufficient to sustain a plasma discharge;
• connecting a power supply to the cladding tube with a positive bias as an anode and to the source tube with a negative bias as a cathode, such that a plasma of the working gas is established in the annular space;
• establishing a circumferential magnetic field around the source tube to confine and shape the plasma;
• whereby the source tube is bombarded with ions from the plasma and burnable poison material is thereby sputtered from the source tube onto the inside surface of the cladding tube to form a burnable poison coating thereon.

A method for coating the inside surface of a zircaloy fuel rod cladding tube with getter material, comprising:

• supporting the cladding tube in a fixture;
• supporting a source tube of getter material coaxially within the cladding tube, thereby defining a cylindrical annular shape between the tubes;
• evacuating the annular space and backfilling the annular space with an inert working gas to a pressure sufficient to sustain a plasma discharge;
• connecting a power supply to the cladding tube with a positive bias as an anode and to the source tube with a negative bias as a cathode, such that a plasma of the working gas is established in the annular space;
• establishing a circumferential magnetic field around the source tube to confine and shape the plasma;
• whereby the source tube is bombarded with ions from the plasma and getter material is thereby sputtered from the source tube onto the inside surface of the cladding tube to form a getter material coating thereon.