NRC grants extension on vent system, risk assessment requirements.
Apr 17, 2017, by Christine Legere
PLYMOUTH — Entergy Corp. will not be required to install upgrades to a heavy-duty vent system at Pilgrim Nuclear Power Station capable of operating and preventing explosions in meltdown conditions, under an extension granted Monday by the Nuclear Regulatory Commission.
Federal regulators also gave Entergy a pass on requirements to re-evaluate risk of earthquakes and floods.
The “reliable hardened containment vents capable of operation under severe accident conditions,” as they are called by the NRC, would prevent over-pressurization in the reactor and containment building, which can lead to gas explosions and radioactive releases such as those at the Fukushima Dai-ichi plant in Japan in 2011.
Pilgrim’s reactor is the same GE Mark I design as the reactors at Fukushima.
The installation of the vent system became mandatory in all GE Mark I and II boiling water reactors via an order issued by the NRC in 2013.
Plant licensees were given until June 2018 to complete installation of a hardened vent system on the torus, a reservoir at the base of the reactor.
In June, plant owner-operator Entergy asked to have an extension on the requirement until December 2019. Since the reactor is set to close permanently in June 2019, the extension is, in essence, an exemption.
David Lochbaum, director of the Nuclear Safety Program for the Union of Concerned Scientists, said hardened vents have been required since the 1990s. The beefed-up systems after Fukushima added the requirement for compressed air or nitrogen near the vent and a power source like a battery to take over and run for 24 hours straight in a station blackout.
“What Fukushima proves is the system only works if you can open the valves,” Lochbaum said. “At Fukushima, they were out in the parking lots looking for car batteries.”
Lochbaum said all components of the system would have to be designed by engineers to handle high temperatures. “It’s not like you can go down to Sears to get it,” he said.
NRC spokesman Neil Sheehan said Pilgrim several years ago installed a vent on the torus that has been found to comply with post-Fukushima requirements. What the system lacks is the dedicated power supply for the vent system that can operate for 24 hours straight. Pilgrim will use the plant’s safety-related batteries, which can have their chargers repowered within eight hours of extended power loss by one of the plant’s generators.
Entergy spokesman Patrick O’Brien said the nitrogen tanks were positioned within 25 feet of the torus, behind a 3-foot wall. The valves can be opened by electricity or gas, he said.
The plant also will use existing radiation monitors rather than adding a dedicated monitoring system contained in the NRC order.
Heather Lightner, a Plymouth resident and member of Concerned Neighbors of Pilgrim, said she was not surprised the extension on the vents was granted. “The NRC has lost its credibility by continually reneging on regulations and requirements they themselves have set,” Lightner wrote in an email. “Shame on the NRC for giving Entergy a free pass on this one.”
Pilgrim Watch, a citizens group that had petitioned the Nuclear Regulatory Commission for a public hearing on Entergy’s extension request, was told last week its petition was denied. “When it’s economic health of the industry versus public safety, economic interests will trump,” Pilgrim Watch President Mary Lampert said Monday. “It is obviously clear lessons were learned at Fukushima, and Pilgrim is the same design. The capability of blowing up is the same.”
Federal overseers should require all components of the hardened vent system for the safety of the region, despite Entergy’s intent to shutter the reactor in two years, Lampert said.
Pine duBois, executive director of the Jones River Watershed Association, has been particularly critical of the location of the massive dry casks, which hold hundreds of radioactive fuel rods and sit within 150 feet of the shore.
“Based on the study we did, I think Pilgrim has been incorrect regarding storms and flooding and should be required to do the study over or move their stuff out of there,” duBois said. “Regulators shouldn’t be putting the public and the environment at risk. If they aren’t going to be required to do all that stuff, then there’s something rotten, and it’s not in Denmark.”
Sheehan said the NRC staff approved deferral of the seismic and flooding requirements “in light of the plant’s remaining operational life span.”
“The time to complete remaining flooding and seismic evaluations is insufficient to complete the assessments, the design and approval of changes to the plant,” Sheehan said.
The state’s two U.S. senators blasted the NRC for granting the exemptions.
“In making this decision, the NRC continues to ignore the concerned voices of Massachusetts communities,” Sen. Elizabeth Warren said in a statement. “Pilgrim may be shutting down in 2019, but that date should have no bearing on Entergy’s — and the NRC’s — responsibility to ensure safe plant operations, each and every day. The risks are too high to allow Entergy to stumble forward for the next two years and disregard investment in critical safety upgrades.”
Sen. Edward Markey also issued a statement Monday, saying the decision on the extensions “undermines the safety of Massachusetts communities living in the shadow of Pilgrim.”
“I urge the NRC to rescind its decision and to hold Pilgrim to the highest safety standard,” Markey said. “Anything less represents an abdication of its role as a safety regulator.”
— Follow Christine Legere on Twitter: @ChrisLegereCCT.