초록 ▼

Nuclear fuel rods are processed to remove moisture in an oven which is evacuated. Measurement of the moisture content in each of a plurality of nuclear fuel rods (typically 44) is carried out by condensing the vapor derived from one randomly-selected control rod in a nitrogen-liquid cooled trap, col

Nuclear fuel rods are processed to remove moisture in an oven which is evacuated. Measurement of the moisture content in each of a plurality of nuclear fuel rods (typically 44) is carried out by condensing the vapor derived from one randomly-selected control rod in a nitrogen-liquid cooled trap, collecting the condensed vapor in magnesium perchlorate, and determining the weight of the collected moisture. Moisture from the one fuel rod is condensed, collected and has its weight determined repeatedly in increments until the difference between the weight of a last increment and of a just preceding increment is less than 1 mg. (The permissible content is 6 mg. or less.) The rods have small perforations through which the vapor can escape. The evacuating system includes a main evacuating channel connected directly to the oven and a branch channel connected to the one fuel rod through the cold trap. The temperature of, and the vacuum in, the one fuel rod is the same as for the other rods and the residual moisture content after processing must be the same.

대표청구항 ▼

A method of determining moisture content within each of a plurality of nuclear fuel rods, each fuel rod including cladding containing therein a plurality of fuel pellets, the cladding of each fuel rod having an opening for escape of air and vapor of moisture from the interior thereof; said method be

A method of determining moisture content within each of a plurality of nuclear fuel rods, each fuel rod including cladding containing therein a plurality of fuel pellets, the cladding of each fuel rod having an opening for escape of air and vapor of moisture from the interior thereof; said method being practiced with apparatus including a drying oven, evacuating means connected to said oven and to at-least one fuel rod randomly selected from said plurality of fuel rods, for evacuating said oven and said at-least one rod, and moisture-vapor condensing means connected to said at-least one rod through said evacuating means; said method including heating said fuel rods in said oven to a predetermined temperature for a predetermined interval of time, while said rods are being heated enabling said evacuating means to evacuate said oven and said at-least one rod, collecting said vapor of moisture from said at least one rod, through said evacuating means, in said moisture-vapor condensing means, condensing said vapor from said at-least one rod in said condensing means, thereafter evaporating said moisture from said at-least one rod condensed in said condensing means, and measuring the quantity of moisture which was condensed from said at-least one rod; the interior of said at-least one rod being maintained through its said opening by said evacuating means and said oven at the same pressure as the interior of the remaining plurality of fuel rods are maintained through their respective openings, whereby the measurement of the moisture within said at-least one rod is used as an equivalent measurement of the moisture within each of the remaining plurality of fuel rods.