Patent Number: 
Section: claims

1. A passive spent fuel cooling system operable to remove decay heat from a fuel handling area of a nuclear reactor plant, comprising:a spent fuel pool,wherein the spent fuel pool contains water,wherein the spent fuel pool contains spent fuel removed from a core of a nuclear reactor of the nuclear reactor plant,wherein the spent fuel generates decay heat, andwherein the spent fuel pool is located in the fuel handling area and,wherein in a boiling event, the water boils to generate steam that mixes with air in the fuel handling area to form a mixture,the mixture containing particulates;a filtration system configured to at least partially remove the particulates, comprising:a discharge path having a first end connected to the fuel handling area and a second end connected to atmosphere;a first vent mechanism positioned in the fuel handling area at an interface of the fuel handling area and the first end of the discharge path,the first vent mechanism comprising at least one temperature-actuated damper that is operable to release the mixture from the fuel handling area into the discharge path;an air filtration unit located in the discharge path,the air filtration unit comprising at least one passive particulate air filter,the at least one passive particulate air filter comprising at least one fiber-containing mat, the at least one fiber-containing mat is structured to trap at least a portion of the particulates from the mixture in the at least one fiber-containing mat to produce a filtered mixture, responsive to the mixture being forced through the at least one passive particulate air filter due to a differential pressure generated in the fuel handling area; anda second vent mechanism located downstream of the at least one passive particulate air filter,the second vent mechanism is structured to release the filtered mixture to the atmosphere. 2. The passive spent fuel cooling system of claim 1 further comprisingat least one drain connected to the air filtration unit,the at least one drain is structured to return to the fuel handling area or other discharge point, condensate generated from the steam and air mixture in the air filtration unit. 3. The passive spent fuel cooling system of claim 2 wherein the at least one drain is two drains. 4. The passive spent fuel cooling system of claim 3wherein one drain of the two drains is located upstream of the at least one passive filter, andwherein the other drain of the two drains is located downstream of the at least one passive filter. 5. The passive spent fuel cooling system of claim 1 wherein the second vent mechanism comprises at least one fail open or gravity operated damper. 6. The passive spent fuel cooling system of claim 1 wherein the first and second vent mechanisms each comprise two dampers. 7. The passive spent fuel cooling system of claim 1 wherein the mixture released from the first vent mechanism has a higher level of particulates as compared to the filtered mixture released from the second vent mechanism. 8. The passive spent fuel cooling system of claim 1 wherein the nuclear reactor is eithera pressurized water nuclear reactor, ora boiling water nuclear reactor. 9. The passive spent fuel cooling system of claim 1 wherein the particulates comprises radioactive particulates.