BRATTLEBORO -- Due to changes in how New England's power grid will be restored to service following a blackout, Vermont Yankee nuclear power plant will soon be asking the Vermont Public Service Board for permission to install a new diesel generator for back-up power.
ISO New England, the independent, not-for-profit organization responsible for overseeing the wholesale side of the electricity industry in New England, recently announced it was shifting its system restoration from a "bottom up" to a "top down" hierarchy.
The process, formerly known as System Restoration and Planning Service and now called Blackstart Service, designates specific generators that will be called upon to re-energize the transmission system after a system-wide blackout.
Approved Blackstart generating units are able to start without an outside electrical supply. The current plan calls for smaller generators, such as the Vernon Hydro Dam, to go online first. The new plan calls for the biggest generators to startup first.
"Vermont Yankee currently credits the Vernon Hydro Dam as its NRC-required Station Blackout AC power source because the dam is a Blackstart facility," said Neil Sheehan, spokesman for the Nuclear Regulatory Commission. "After the end of the year, the Vernon Hydro Dam will no longer be maintained as a Blackstart facility."
Sheehan said Station Blackout refers to the loss of all off-site power sources, which is what occurred
ISO New England and TransCanada, which owns the Vernon Hydro Dam, have decided not to maintain the dam as a Blackstart facility.
"Therefore, Vermont Yankee will need a new AC power source in order to continue to meet the NRC requirements for coping with a Station Blackout condition," he said.
Though the Vernon Hydro Dam will no longer be a formal power source of back-up power, said Williams, the hard-wire tie-in between it and Yankee will remain.
TransCanada did not return a phone call for comment on the new procedure.
The diesel generator is designed to produce 3,000 kilowatts of power, which would be used to safely cool down the reactor during a blackout, said Rob Williams, spokesman for Entergy Vermont Yankee.
"We filed a notice with the Windham Regional Commission and the town of Vernon regarding our intent to install a diesel-powered generator to replace one of the plant's three back-up power sources," he said.
According to the notice, Entergy plans to file a petition to the PSB for a certificate of public good by Friday, Sept. 7.
Chris Campany, the executive director of the Windham Regional Commission, said any utility is required by law to notify the commission when it intends to install a power generating source.
Because upon first look at the letter it doesn't appear the installation of the generator is a matter of regional significance, the WRC has not yet decided whether it will become an intervenor in the PSB proceedings.
The generator and its associated equipment, which includes a diesel fuel tank, will be located inside the plant's protected fence area, said Williams.
"NRC safety requirements address the need for nuclear power plants to have a source of power when the normal power supply is lost," he said.
Because back-up power is needed for safety, the construction and operation of the generator is under the exclusive jurisdiction of the NRC, he said.
"Even though a state can't impose any regulations that conflict with NRC requirements, we respect the process of the PSB so we are petitioning the board for the issuance of a CPG," said Williams.
However, because a new concrete pad and building to house the generator will need to be built, a CPG is required, he said.
Ray Shadis, spokesman for the New England Coalition, which has opposed Yankee's operation for the past 40 years, said only operations directly related to nuclear safety are entirely preempted from state regulation.
"Further, the state even today regulates certain aspects of existing emergency generators -- such as exhaust emissions, petroleum leaks and noise," he said.
Shadis said NEC believes the affected soil area must be radiologically surveyed before pouring a concrete slab as it will be more costly to conduct preliminary decommissioning surveys through and under a slab when the time comes.
"Vermonters are entitled to a return on surplus decommissioning funds and therefore would be financially affected by unnecessarily more expensive decommissioning processes," said Shadis. "The Vermont PSB has a right to investigate this project's affect on those interests."
"We believe the PSB will recognize that the project is essential to Yankee's continued ability to operate safely and in accordance with federal law and will approve this project without undue delay," said Williams.
The diesels actually drive the cooling systems needed to safely shut down and cool the reactor, he said.
Yankee currently has two diesel generators on site.
"If they're unavailable, the third source for station blackout is the Vernon Hydro Dam," said Williams.
In addition, the plant has battery backup to power other safety related components.
Sheehan said the installation of the new diesel generator is not related to the post-Fukushima requirements.
"Plants were already required to maintain Station Blackout power capabilities," he said.
However, he added, Entergy will need a license amendment from the NRC in order to make this change.
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