Jurors spent hours yesterday in U.S. District Court in Toledo reviewing footage of boric acid crystals that encrusted Davis-Besse's old reactor head as far back as 1996.
Government prosecutors are using the evidence to bolster their claim that FirstEnergy Corp. engineers lied in maintenance documents the utility submitted to the Nuclear Regulatory Commission in the fall of 2001.
The trial, which began Monday, is the first of two in which former engineers face up to five years in prison and separate $250,000 fines if convicted of lying to the government.
David Geisen, a former FirstEnergy employee who now lives in Wisconsin, is on trial with Rodney N. Cook, a Tennessee contractor. Both are believed to have had a role in generating data or authoring documents that wound up being presented to the NRC.
So is Andrew Siemaszko, a former FirstEnergy engineer who now lives in Texas. He is to be tried later.
The crystals usually come from boric acid that leaks from reactor-head nozzle flanges of nuclear reactors. Boron residue forms as the reactors, which can operate in excess of 600 degrees, shut down and cool off.
The NRC has tolerated minor flange and valve leakage for years, yet it was taken aback by the amount of boron that had crystallized on Davis-Besse's old reactor head.
Far from being a light dusting, it was dense enough on some spots by 2000 to have the appearance of coral.
Melvin S. Holmberg, an NRC reactor inspector, said he learned after reviewing copied footage that the boron residue built up during three refueling outages before the historic cavity in Davis-Besse's old reactor head was discovered in 2002.
He said it should have tipped off someone that the plant's leakage was not minor.
During the 1996 refueling outage, Davis-Besse's reactor head had so much boron residue on it that only 51 of its 69 nozzles could be properly inspected with a remote-controlled camera, according to Mr. Holmberg's testimony.
By the 1998 refueling outage, the number of viewable nozzles had dropped to 43. During the 2000 outage, it was only 23 - a mere one in three.
Mr. Holmberg said there were so many hard chunks of residue in 2000 that the remote-controlled camera "appeared to bury itself in boric acid deposits" as it was maneuvered into position.
Yet the paperwork that FirstEnergy presented the NRC in the fall of 2001 asserted the head had been cleaned and properly inspected during all three of those outages.
At the time, the agency was deciding whether to execute the first emergency shutdown order it had prepared for a U.S. nuclear plant since 1987.
Davis-Besse was shut down for more than two years beginning Feb. 16, 2002.
Three weeks later, on March 6, 2002, a six-inch cavity from leaking acid exposed all but a stainless steel liner that was no more than three-eighths of an inch thick. In that spot, it was even thinner. And the liner had started to bulge and crack.
If it had ruptured, radioactive steam would have formed in containment for the first time in the United States since 1979, when half of Three Mile Island Unit 2's reactor core melted near Harrisburg, Pa.
Some NRC staffers, suspecting a problem was brewing in the fall of 2001, tried to get Davis-Besse shut down no later than Dec. 31, 2001. FirstEnergy pleaded with the agency to stick to the utility's planned refueling outage date of March 31, 2002, for financial reasons. Nuclear plants generate nearly $1 million a day in power.
Senior NRC officials ultimately agreed to let the plant continue until that Feb. 16. The agency's Office of Inspector General later said they put profits ahead of northern Ohio's safety by agreeing to that compromise.
Nuclear plants are refueled once every 18 months to two years, depending on the grade of uranium they have in their fuel rods.
At Davis-Besse, refuelings have occurred once every two years since the mid 1990s.
Maintenance work for reactors is reserved for refueling outages to minimize worker exposure to radiation.
Ron Lloyd, a retired NRC inspector who was part of the agency's "Lessons Learned Task Force," testified that he vividly recalls details about some FirstEnergy documents because of the number of errors uncovered.
John Bradley Martin, a nuclear safety consultant who spent 26 years with the NRC, including two stints as a regional administrator, said Mr. Geisen made a puzzling comment to him while lifting a mode restraint that had been blocking the plant's restart during the 2000 refueling outage.
"What struck me was [the comment from Mr. Geisen] was made on the basis the [reactor] head would [eventually] be cleaned, not that it was," Mr. Martin said.
At the time, Mr. Martin was a member of FirstEnergy's company review board for Davis-Besse.
He said Mr. Geisen never told that board about the boron that was still on the reactor head.
Andrew Wise, one of Mr. Geisen's attorneys, asked him if plant employees "had become deadened by the boric acid they saw."
"Oh, I think that's true," Mr. Martin said.
The trial resumes at 9 a.m. Tuesday. It has been delayed until then because of scheduling conflicts.
Contact Tom Henry at: firstname.lastname@example.org or 419-724-6079.