Zirconium cladded pressurized water reactor nuclear fuel element

Claim 2

A pressurized water reactor nuclear fuel element comprising: an elongated sealed tubular cladding container having an inner wall, said container consisting essentially of a cladding material selected from zirconium or a zirconium alloy, said cladding material containing less than four percent by weight of alloying materials including an oxygen content of less than 600 parts per million by weight; a nuclear fuel material sealed within said cladding container with a gap provided between said fuel material and said inner wall; and a helium gas atmosphere in the gap of said sealed container, said helium gas being pressurized to a pressure of between 150 to 500 pounds per square inch at ambient temperature.

Claim 3

A pressurized water reactor nuclear fuel element as defined in claim 1 wherein said cladding material is zirconium metal.

Claim 4

A pressurized water reactor nuclear fuel element as defined in claim 1 wherein said cladding material is a zirconium alloy.

Claim 5

A pressurized water reactor nuclear fuel element as defined in claim 3 wherein said zirconium alloy contains about 2.5 percent by weight niobium.

Claim 6

A pressurized water reactor nuclear fuel element as defined in claim 3 wherein said zirconium alloy containing about 1.2 to 1.7 percent tin, 0.7 to 0.20 percent iron, 0 to 0.8 percent nickel and 0.05 to 0.15 percent chromium.

Claim 7

A pressurized water reactor nuclear fuel element as defined in claim 5 wherein said zirconium alloy is Zircaloy-2.

Claim 8

A pressurized water reactor nuclear fuel element as defined in claim 5 wherein said zirconium alloy is Zircaloy-4.

Claim 9

A pressurized water reactor nuclear fuel element as defined in claim 1 wherein said tubular cladding container has a wall thickness of about 0.022 inch.

Claim 10

A pressurized water reactor nuclear fuel element as defined in claim 8 wherein said nuclear fuel is in the form of cylindrical pellets having a length of about 0.4 to 0.6 inch and a length to diameter ratio of about 1.2:1.

Claim 11

A pressurized water reactor nuclear fuel element as defined in claim 1 wherein said helium gas is pressurized to a pressure of between 200 to 500 pounds per square inch at ambient temperature.

Claim 12

A pressurized water reactor nuclear fuel element comprising: an elongated sealed tubular cladding container having an inner wall, said container consisting essentially of a zirconium alloy containing about 1.2 to 1.7 percent tin, 0.7 to 0.20 percent iron, 0 to 0.8 percent nickel and 0.05 to 0.15 percent chromium, with a total of less than four percent by weight of alloying materials present, including an oxygen content of less than 600 parts per million by weight, said cladding container having a wall thickness of about 0.022 inch; cylindrical pellets of a nuclear fuel material sealed within said cladding container, said pellets having an outer diameter of about 0.008 inch less than the inside diameter of the tubular cladding container to form a gap between said pellets and said inner wall; and a helium gas atmosphere in said gap of said sealed container, said helium gas being pressurized to a pressure of between 150 to 500 pounds per square inch at ambient temperature.

Claim 13

A pressurized water reactor nuclear fuel element comprising: an elongated sealed tubular cladding container having an inner wall, said container consisting essentially of a zirconium alloy containing about 1.2 to 1.7 percent tin, 0.7 to 0.20 percent iron, 0 to 0.8 percent nickel and 0.05 to 0.15 percent chromium, with a total of less than four percent by weight of alloying materials present, including an oxygen content of less than 600 parts per million by weight, said cladding container having a wall thickness of about 0.022 inch; cylindrical pellets of a nuclear fuel material sealed within said cladding container, said pellets having an outer diameter of about 0.008 inch less than the inside diameter of the tubular cladding container to form a gap between said pellets and said inner wall; and a helium gas atmosphere in said gap of said sealed container, said helium gas being pressurized to a pressure of between 150 to 500 pounds per square inch at ambient temperature.