BRATTLEBORO -- Sixteen months after shutdown of the reactor at Vermont Yankee nuclear power plant, offsite emergency planning will no longer be needed, according to documents filed by Entergy with the Nuclear Regulatory Commission.
"Within 15.4 months after shutdown, no credible accident at VY will result in radiological releases requiring offsite protective actions," states the request for exemption from federal regulations related to the emergency planning zone around nuclear power plants. "The potential for a release of a large radiological source term to the environment from the high pressures and the temperatures associated with reactor operation will no longer exist."
Entergy has notified the state and the federal government that it plans to permanently cease operations at Yankee in December of this year.
Neil Sheehan, spokesman for the NRC, said staffers are evaluating Entergy's request for exemption, which includes the mathematical formulas used to support its conclusions.
"They show that the spent fuel will have decayed to the extent that the requested exemption can be implemented without compensatory actions," he said. "The heat load starts to drop off pretty dramatically after it's moved into the spent fuel pool."
Sheehan said the NRC has not yet received Entergy's timetable for removing all of the fuel from the reactor and placing it in the spent fuel pool.
"Before any fuel could be moved, plant personnel would have to let the reactor cool for at least a brief period of time," he said. "They would then have to flood up the reactor cavity and remove the reactor vessel head. Typically, the fuel can be moved from the vessel to the pool, underwater and via the transfer canal, over the course of several days, but this is not a refueling and maintenance outage so there are not the kind of time constraints that exist during those activities.
According to Entergy's review, "Seventeen days after shutdown, radiological consequences of design basis accidents will not exceed the limits of the Environmental Protection Agency Protective Action Guides ... Therefore, offsite emergency response plans will no longer be needed for protection of the public ..."
Sheehan said there are a pair of key notifications to the NRC once a plant has permanently ceased operations: Notification of the permanent cessation of operations and notification that all of the fuel has been removed from the vessel.
The exemption requested by Entergy is permitted under the NRC's regulations and is consistent with exemption requests submitted by the operators of other nuclear power plants that have been shutdown, said Sheehan.
Entergy is requesting an approval of its submission by Dec. 1, 2015, with an effective date of April 2016, said Sheehan.
Chris Recchia, the commissioner of the Department of Public Service, said the state of Vermont doesn't really have a say in the regulation exemption process.
"The NRC does provide for public comment, but they don't have to respond to it," he said. "We are looking for a constructive way to engage with the NRC and Entergy on this issue."
"The state will express its interests regarding the decommissioning process but, admittedly, the EPZ will look different than the current EPZ looks today," said Joe Flynn, the director of Vermont's Division of Emergency Management and Homeland Security. "I can't say exactly what it will look like because that would be pure speculation."
Flynn said if the NRC approves the license exemption, there would be no further regulations that require Entergy to provide emergency planning funding to the EPZ.
"There is currently nothing in the regulations that requires a company thereafter that resembles the current radioactive emergency response plan funding stream."
Even if the NRC approves the exemption, said Flynn, Vermont agencies will still play an active role in monitoring the plant's status and its decommissioning process. Those agencies include the Department of Public Service, the Agency of Natural Resources and the Department of Health.
According to Entergy, if the spent fuel cooling system failed, it would take 74 hours for the water to reach a boiling point and then another 16 days for the water to boil off to within three feet of the top of the fuel assemblies.
"Due to the slow rate of spent fuel pool water boil-off, adequate time will be available to restore cooling or makeup ..." stated the documents.
The cooling system has redundant pumping capabilities and power supplies, which include both electric-driven and diesel-driven fire pumps. In addition, Yankee has an engine driven pump that can withdraw water from the basin beneath the cooling towers as a source of makeup water.
Entergy's exemption request won't affect emergency shelter funding negotiated between the state, Entergy and the Vermont & New Hampshire Upper Valley Red Cross, said Flynn.
"The fiscal year 2015 budget is still working toward a capacity of sheltering 6,000 Vermonters," said Flynn. "After the reactor has cooled, we will have a greater shelter capability because of the efforts we have undertaken. The capacity will still be there, but what might cause people to evacuate will change over time."
Bob Audette can be reached at email@example.com, or at 802-254-2311, ext. 160. Follow Bob on Twitter @audette.reformer.