On Monday the Vermont Yankee nuclear power plant started producing power at full capacity again, after technicians repaired one of two motor generators, which control the flow of reactor cooling water.
On June 18 an electrical failure in one of the motor generators caused the reactor to reduce power output to 38 percent. Technicians removed the electric motor and sent it offsite, reinstalling a repaired motor on July 2.
“About two weeks is a reasonable time considering the motor had not been removed before,” said plant spokesman Rob Williams. “It’s really a credit to the technicians and engineers who were able to rig that motor successfully out and back into place.”
The problem was not safety related, said Williams. Even with this problem, he added, the plant has been on line and producing electricity for 247 days straight.
Although one critic agreed that the repair had been made reasonably fast, he said that the failure “indicates that they have not fully addressed their mechanical problems at the plant.”
“Back in September, if they had done a thorough check of all similar equipment in the plant, they may well have avoided the problem this time,” said Ray Shadis, a technical consultant for the New England Coalition, an anti-nuclear advocacy group. In September 2011, the other generator suffered a different problem, which resulted in a reduced 46 percent power output.
Shadis also criticized the plant’s track record with equipment repairs and reduced power output, comparing the plant’s maintenance method to “whipping an old tired horse and trying to make it into a racehorse.”
Williams added that the warm summer weather reduces plant efficiency, by an estimated 21 to 26 megawatts. This is because cooling towers need to be used, he said, and added: “That’s just the nature of how steam-generating plants operate.”
