Enhanced oxidative decladding technology for recovery of used nuclear fuel

A system for oxidative decladding for recovery of used nuclear fuel (UNF) comprising:

• a vessel composed of a material that is compatible with oxidative and reductive atmospheres up to 800° C. and overpressure conditions of up to 2 atm, wherein the vessel comprises:
• a main vessel unit having an open top;
• and
• a lid coupled to the main vessel unit and enclosing the open top to form a gas tight seal;
• a coating formed in an interior of the main vessel, the coating being one of:
• high-purity alumina (Al2O3) or fused quartz/silica (SiO2);
• a first inlet port for injecting the oxygen enriched gas into the vessel;
• a second inlet port for injecting hydrogen gas into the vessel:
• at least one gas outlet port discharging off gases and waste gases out of the vessel;
• at least one fuel basket removably positioned within the vessel, the at least one fuel basket comprises a container divided into a plurality of compartments, each compartment configured to hold a portion of a plurality of UNF rods in an upright manner, the container having a bottom surface and side walls extending up from the bottom surface, wherein the bottom surface and side walls have a meshed configuration allowing for decladding and separation of UNF meat in pulverized form to fall through the meshed configuration;
• a basket support formed within the vessel, the basket support securing the at least one basketed within the vessel in an upright manner and for distributing a weight of the at least one basket to a load bearing structure;
• a plurality of heating elements flanking the at least one fuel basket;
• and
• a funnel formed on a bottom area of the main vessel;
• wherein the oxygen enriched gas is injected into the first inlet port, the plurality of heating elements converting UO2 matrix in the UNF rods to U3O8 and comminuting the fuel meat from claddings of the plurality of UNF rods, wherein the hydrogen gas injected from the second inlet port is used for hydrogen reduction of the fuel meat.

A method for recovering used nuclear fuel (UNF) from UNF rods, comprising:

• debunding UNF rods from a light water reactor (LWR) fuel assembly;
• perforating each UNF rod down a length of each UNF rod;
• placing each UNF rod in a fuel basket, the fuel basket comprising a container divided into a plurality of compartments, each compartment configured to hold a plurality of the UNF rods in an upright manner, the container having a bottom surface and side walls extending up from the bottom surface, wherein the bottom surface and side walls have a meshed configuration allowing for decladding and separation of UNF meat in pulverized form to fall through the meshed configuration;
• placing the fuel basket into a vessel composed of a material that is compatible with oxidative and reductive atmospheres up to 800° C. and overpressure conditions of up to 2 atm, wherein the vessel comprises:
• a main vessel unit having an open top;
• and
• a lid coupled to the main vessel unit and enclosing the open top to form a gas tight seal;
• injecting oxidizing reagents into the vessel, wherein the oxidizing reagents is an oxygen enriched gas;
• and
• heating an interior of the vessel with a plurality of heating elements flanking the fuel basket to a temperature between 300° C. and below 700° C.;
• wherein the plurality of heating elements convert UO2 matrix in the UNF rods to U3O8 and comminuting the fuel meat from claddings of the plurality of UNF rods, wherein a hydrogen gas injected into the vessel is used for hydrogen reduction of the fuel meat.