Article by David Shaffer for the Star Tribune. May 19, 2011
A former engineer at the Monticello nuclear power plant says he raised concerns six years ago about safety vents like the ones that may have worsened Japan’s nuclear accident, but the industry didn’t want to hear his concerns.
Anthony Sarrack, working with another Monticello engineer, wrote a white paper in 2005 raising concerns about a venting system designed to rid boiling water reactor containment vessels of excessive pressure during accidents by releasing it outside. The system is designed to prevent a rupture of the containment vessel, as experts fear happened at the Fukushima Daiichi nuclear plant.
But Sarrack says he left the industry in 2006 after spending a frustrating 19 months trying to persuade the regulators and industry officials to consider his proposed solution.
“As an industry, they don’t want to make changes,” he said.
U.S. Sen. Al Franken, D-Minn., cited the white paper in a letter to the Nuclear Regulatory Commission on Wednesday, saying it “raises serious concerns about the capacity of the venting systems at Monticello and the other U.S. boiling water reactors to withstand major shocks and function effectively in an emergency.”
The white paper was discovered in the NRC’s electronic library by David Lochbaum, director of the nuclear safety project for the Union of Concerned Scientists. He turned it over to Franken after a member of the senator’s staff contacted him about a New York Times report on the venting concerns at the Japanese plant.
In 2005 and 2006, Sarrack urged the industry to consider a venting system that would automatically release excessive pressure from the containment vessel, avoiding the need for operators to act or the need for backup power. Japan’s power plant lacked electricity after the earthquake and tsunami in March. The plants are similar in design to Monticello.
The Monticello plant has a backup system powered by compressed nitrogen that officials said would power the vents if the plant lost all power. The venting system has never needed to be used, the utility said.
Sarrack’s paper did not predict explosions, which experts say likely happened in Japan when hydrogen built up from an overheated core. But Sarrack said in an interview Thursday that automatic, or passive vents, might have prevented the blasts.
Nuclear Management Corp., which operated Xcel Energy Inc.’s two Minnesota power plants from 2000 to 2008, disagreed with Sarrack’s idea in 2005, and rejected the modification. That was partly because managers were concerned that once an automatic vent was opened, it would release radioactive gases until it was closed manually, according to an Xcel Energy official who worked at Nuclear Management at the time.
Terry Pickens, director of nuclear regulatory policy for Xcel Energy, said plant officials encouraged Sarrack to raise the issue within the nuclear industry and paid his travel expenses to a conference to give a presentation.
“They encourage people to ask questions like this, so he brought it forward,” Pickens said.
Sarrack, who now works in Texas, agreed that the plant operators never tried to silence him. But he said managers gave him a poor performance review and he left the company in frustration. Xcel, which now operates the plants, declined to comment on Sarrack’s job performance.
Doug True, president of Erin Engineering and Research, a Walnut Creek, Calif., nuclear consulting firm, said Sarrack’s proposal “never got any traction” in the industry because many people disagreed with its merits.
“There was lot of consideration on how to use these vents, and on balance people generally felt the way they were installed was the preferred way,” he said.
An NRC spokeswoman said the vents will be reviewed as the agency studies the lessons from the Fukushima disaster.
“I can’t speculate on what will come out from the agency’s review,” Prema Chandrathil of the NRC’s Chicago office said in an e-mail. She also said the NRC will respond to Franken’s letter.