Officials hope nuclear rods are in pool
- Keay Davidson, Chronicle Science Writer
Saturday, July 17, 2004
PG&E Co. officials are seeking three missing radioactive portions of a used nuclear fuel rod from the long-defunct Humboldt Bay nuclear power reactor near Eureka.
Each fragment -- 18 inches long and about a half-inch thick -- contains used uranium fuel inside a stainless-steel cladding, Pacific Gas and Electric officials said in a statement Friday.
For now, utility officials' working hypothesis is that the rod fragments will eventually be found somewhere inside the cluttered reactor pool at the plant. Still, while "very confident" that all will turn out well in the end, they can't yet totally rule out an unsettling possibility -- that at some time over the last third of a century, the rods somehow left the plant for points uncertain.
PG&E analysts noticed "the first indication of a discrepancy" in their records on June 23, the statement says. Since July 7, they have used robotic arms to search for the rod fragments inside the reactor pool.
It's a slow search, because the pool is a watery jungle of metal and radioactive leftovers. The pool is 22 feet wide, 28 feet long, and up to 36 feet deep; it contains 390 "fuel assemblies," each of which is a bundle of a few dozen multiple used fuel rods.
The seventh commercial nuclear reactor to be operated in the United States, the 65-megawatt Humboldt Bay reactor generated energy for consumers along the Northern California coast and points inland from 1963 to 1976. Afterward the reactor was shut down, but the used nuclear fuel is still stored in the pool.
On Friday, PG&E spokesman John Nelson said the utility was "very confident" the three rod fragments would eventually be found in the pool, perhaps within a few weeks.
The reason for their optimism is that searchers this week found fragments of the original, 7-foot-long fuel rod -- from which the three 18-inch pieces were taken -- in the pool. That verified old records that indicated the original section was placed inside the pool after the three segments had been excised.
Hence, Nelson said, utility officials are confident that the three shorter rod segments -- which were originally destined to be shipped to an Ohio laboratory for analysis, but probably were never sent -- will also turn up in the pool, sooner or later.
E-mail Keay Davidson at kdavidson@sfchronicle.com.
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