Patent Number: 
Section: claims

1. A method of protecting a uranium chloride fuel salt comprising:creating a protected fuel salt including UCl3, NaCl or KCl, and an initial mass of chloride salts of activation dopants, wherein the protected fuel salt has an FOM of greater than 1.0; andfissioning the protected fuel salt in a nuclear reactor to obtain a fissioned fuel salt having an FOM of less than 1.0;wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 300 days of fission due to the conversion of activation dopants into protecting isotopes. 2. The method of claim 1 wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 200 days of fission due to the conversion of activation dopants into protecting isotopes. 3. The method of claim 1 wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 100 days of fission due to the conversion of activation dopants into protecting isotopes. 4. The method of claim 1 wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 60 days of fission due to the conversion of activation dopants into protecting isotopes. 5. The method of claim 1 wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 45 days of fission due to the conversion of activation dopants into protecting isotopes. 6. The method of claim 1 wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 30 days of fission due to the conversion of activation dopants into protecting isotopes. 7. The method of claim 1 wherein the initial mass of chloride salts of activation dopants is sufficient to cause the FOM of the fissioned fuel salt to fall below 1.0 within 10 days of fission due to the conversion of activation dopants into protecting isotopes. 8. The method of claim 1 wherein the protected fuel salt consists of:UCl3;one or more chloride salts selected from NaCl, MgCl2, CaCl2, or KCl; andone or more chloride salts of activation dopants wherein the activation dopants are selected from stable isotopes of Co, Cs, Ce, La, Pr, Nd, Bi, Ir, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Ra;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes. 9. The method of claim 8 wherein the one or more chloride salts of activation dopants are selected from CoCl3, CsCl, CeCl3, BiCl3, IrCl3, LaCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, TbCl3, DyCl3, HoCl3, ErCl3, TmCl3, YbCl3, LuCl3, or RaCl2. 10. The method of claim 1 wherein the protected fuel salt consists of:UCl3;UCl4;one or more chloride salts selected from NaCl, MgCl2, CaCl2, or KCl; andone or more chloride salts of activation dopants wherein the activation dopants are selected from stable isotopes of Co, Cs, Ce, La, Pr, Nd, Bi, Ir, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Ra;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes. 11. The method of claim 10 wherein the one or more chloride salts of activation dopants are selected from CoCl3, CsCl, CeCl3, BiCl3, IrCl3, LaCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, TbCl3, DyCl3, HoCl3, ErCl3, TmCl3, YbCl3, LuCl3, or RaCl2. 12. The method of claim 1 wherein the protected fuel salt consists of:UCl3;NaCl;one or more chloride salts of activation dopants wherein the activation dopants are selected from stable isotopes of Co, Cs, Ce, La, Pr, Nd, Bi, Ir, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Ra;and no more than 10 wt. % of any other component;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes. 13. The method of claim 1 wherein the protected fuel salt consists of:UCl3;UCl4;NaCl;one or more chloride salts of activation dopants wherein the activation dopants are selected from stable isotopes of Co, Cs, Ce, La, Pr, Nd, Bi, Ir, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Ra; andand no more than 10 wt. % of any other component;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes. 14. The method of claim 1 wherein the protected fuel salt consists of:UCl3;KCl;one or more chloride salts of activation dopants wherein the activation dopants are selected from stable isotopes of Co, Cs, Ce, La, Pr, Nd, Bi, Ir, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Ra;and no more than 10 wt. % of any other component;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes. 15. The method of claim 1 wherein the protected fuel salt consists of:UCl3;UCl4;KCl;one or more chloride salts of activation dopants wherein the activation dopants are selected from stable isotopes of Co, Cs, Ce, La, Pr, Nd, Bi, Ir, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Ra;and no more than 10 wt. % of any other component;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes. 16. The method of claim 1 wherein the protected fuel salt consists of:UCl3;KCl;one or more chloride salts of activation dopants selected from CoCl3, CsCl, CeCl3, BiCl3, IrCl3, LaCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, TbCl3, DyCl3, HoCl3, ErCl3, TmCl3, YbCl3, LuCl3, or RaCl2;and no more than 10 wt. % of any other component;wherein the protected fuel salt has an FOM greater than 1.0 prior to fissioning and, after no more than 300 days of fissioning, the fissioned fuel salt has an FOM of less than 1.0 due to the conversion of the activation dopants into protecting isotopes.