Vt. Yankee permitted to reduce safety tests
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By SUSAN SMALLHEER Staff Writer - Published: January 11, 2009
BRATTLEBORO – The Nuclear Regulatory Commission has given Entergy Nuclear permission to reduce the number of times it conducts tests on control rods, a key safety system at Vermont Yankee plant.
In a decision released earlier this week, the NRC granted a license amendment to Entergy that will allow it to test the control rods on a monthly basis. The control rods are now tested weekly. Entergy filed the request in February 2008.
The control rods are inserted in the reactor core in the event of an emergency or a power reduction to reduce the amount of nuclear reaction in the plant.
Entergy Nuclear spokesman Laurence Smith said Friday that the plant had requested the reduction in order to put less stress on a "sensitive" component at the plant by needlessly testing it.
Smith said Vermont Yankee was one of the last nuclear reactors in the country to get permission from the NRC to change the standards for control rod testing, but according to the NRC only a handful of the 100 commercial reactors in the country have received such permission.
"We're taking advantage of industry experience," Smith said. "It's good for us. It's a better way to do things."
"The change streamlines the actions and surveillances for the control rod system in areas such as scram time surveillance testing, where for instance, a small sampling of the control rods are tested at a slightly more frequent interval," Smith said. "This is allowed by the very good VY and industry performance of this equipment. A further benefit is less reactivity manipulations are necessary, which minimizes the opportunity for errors to occur and less wear on the equipment."
Smith said that Vermont Yankee would not implement the changes to its technical specifications until procedures and programs are revised and any training necessary is conducted.
According to Sarah Hofmann, the director of public advocacy for the Department of Public Service, the state remained neutral on Entergy's control rod request. She stressed that the control rod testing issue was not a license renewal issue.
"The state didn't take a stand on the recently approved change to testing of the control rods. It reduces the frequency of control rod testing to present industry practices. Some of the benefits are less impact to control room operators and a reduction in the likelihood of errors while not sacrificing quality. The DPS was aware of the change but did not object to this change," Hofmann said.
Neil Sheehan, spokesman for the Nuclear Regulatory Commission, said the following plants have either requested or obtained approval of the same change: Susquehanna, Grand Gulf, Browns Ferry, River Bend, Brunswick, Nine Mile Point, Fermi and Duane Arnold.
Of those plants, only Grand Gulf in Mississippi and River Bend in Louisiana are owned by Entergy Nuclear or its associated companies.
Sheehan said the technical specifications for Vermont Yankee currently require that the plant's control rods be tested weekly. He said that Entergy control room operators move the rods one notch, with the purpose to confirm control rod insertion capability.
He said that the basis for Entergy seeking a revision of the surveillance testing requirements "is it will prevent unnecessary control rod manipulations. More specifically, it will reduce wear and tear on the system. It will also reduce the number of potential reactivity control errors, including mispositioning events, that could occur because it reduces the number of operator actions."
"The change has been determined by the NRC staff to be acceptable because of the demonstrated historic reliability of the control rod drive mechanisms. Also, the monthly tests will continue to provide a large number of tests to provide confidence that any problems with the system would be identified," he said.
Contact Susan Smallheer at susan.smallheer@rutlandherald.com.
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