Complex suspends acceptance of nuclear fuel rods
A sprawling nuclear-fuel storage complex near Misawa Air Base has suspended acceptance of spent nuclear fuel rods until storage tanks can be inspected for possible faulty welds.
According to Japanese news reports, Japan Nuclear Fuel Ltd. officials said a subcontractor has admitted that the welding of seams may have not been done properly inside several water tanks that keep uranium-235 and uranium-238 fuel rods from overheating.
In January 2002, one of three stainless-steel storage tanks measuring 89 feet by 40 feet developed a leak that allowed 1,056 gallons of radioactive cooling water to escape.
Workers had to remove 165 tons of radioactive fuel rods, then drain the tank to search for the leakage, a process that took nearly 10 months.
Several tiny holes measuring less than 0.1mm in diameter were found where seams had been welded.
Because a portion of the tank being mated with another segment was shorter than what engineering plans called for, workmen extended the length of the gap at a seam by expanding the welded area, NFL officials explained.
It was along that extended weld where the leakage was detected.
Plant officials have said at no time did radioactive water escape from the Rokkasho facility, 25 miles north of Misawa.
Spent fuel rods are brought to the facility for storage from nuclear-power plants throughout Japan.
Japan’s first commercial nuclear-fuel reprocessing facility is under construction at the site and should be completed in 2005, according to an English-language company brochure.
Until seam welds in the other two storage tanks can be inspected, plant officials said they would not accept additional fuel rods for storage until April.
An estimated 90 tons of fuel rods was set for delivery to the plant during the first three months of 2003, officials said.