(Reuters circulated the following story on July 19.)
LOS ANGELES — Pacific Gas & Electric said last week that it had lost track of three pieces of spent nuclear fuel it last used in the late 1960s, although the utility said there was no threat to public safety.
The San Francisco-based utility, a unit of PG&E Corp. said the nuclear fuel was from the now closed Humboldt Bay nuclear plant near Eureka in northern California.
Pacific Gas & Electric said there was a discrepancy in its records related to the movement of the used nuclear fuel more than 34 years ago.
The used nuclear fuel consisted of three, half-inch diameter by 18-inch long segments, weighing a total of about 4 pounds, which were cut from a single, seven-foot fuel rod in 1968.
“You could use that kind of material for a dirty bomb but it was probably lost long before 9/11 and they are just now accounting for it,” said David Lochbaum, nuclear safety engineer for the Union of Concerned Scientists, an environmental advocacy group.
“It is likely it was mistaken for something else and shipped off-site. It is not likely that someone took it off-site either maliciously or inadvertently,” he added, noting it may be have been removed during a site clean-up some years ago.
The Humboldt Bay reactor operated from 1963 to 1976. The utility said no fuel has been shipped off-site since 1974.
MINUTES REVIEWED
The utility said it discovered that the fuel was missing on June 23 when it reviewed minutes of “on-site review committee” meetings dating from 1968. Records provided conflicting accounts about what happened to the pieces.
The review was to prepare for moving used fuel from the pool to dry cask storage and decommissioning the plant.
“The fuel rod segments remain in the used fuel pool, or were shipped off-site to an appropriate controlled facility, either for analysis or reprocessing,” said Greg Rueger, the utility’s Chief Nuclear Officer.
“However, we must ensure that we have accurate records and that entails a meticulous search of the pool itself, to confirm the location of these three used fuel segments,” he added. Lochbaum said the Nuclear Regulatory Commission was making nuclear plant operators physically look at spent fuel after operators of the Millstone nuclear plant in Connecticut lost track of a couple of rods about three years ago.
“When they do inventories they really have to look at it (now),” said Lochbaum, noting that as the plant had not operated for many years there would have been a considerable decay in the radioactivity of the rods.
The utility said the investigation into the location of the rods could take several more weeks to complete.