Built in 1972 on the shores of Cape Cod Bay, Pilgrim Nuclear Power Station has been the subject of controversy and concern for decades. Now it’s scheduled to close in the next few months. This is part three of a three-part series on the plant as it heads towards permanent shutdown in mid-2019. Read parts one and two.

Pilgrim Nuclear Power Station is nearly 50 years old. It’s moving toward a permanent shutdown in four months, but there are still concerns about safety. When a nuclear power plant closes, it leaves radioactive waste, and a lot of unanswered questions.

The reactor team practices nuclear shutdown drills regularly, in a mock reactor room. On one particular day, Christina Renaud, who works for the company Entergy, which owns the plant, describes a situation they're practicing for.

"It's the middle of February. We have a large storm, it's heavy snow, and a tree actually gets weighed down enough that it crosses over 345 kv lines," she said to the training crew.

This situation, an event where the nuclear reactor would undergo a scram, or an emergency shutdown, is not very different from what happened last winter, when a storm knocked out power at Pilgrim and took it offline for weeks.

As the plant ages, nuclear opponents are increasingly worried that an accident similar to the one in this drill could lead to a nuclear meltdown. Harwich resident Diane Turco, a longtime critic of the plant, is concerned that the consequences of a nuclear explosion would have far-reaching effects. She has overlaid an image of the radioactive plume generated after the 2011 Fukushima Daiichi plant explosion on a map of New England.

"We superimposed that data over Pilgrim, and you can see where it goes," she said.

The plume she points to would stretch from Long Island to Maine. And though the plant is closing soon, the risk for a nuclear meltdown still remains, even after it’s stopped generating power. One morning, Turco visited the plant to point out what she’s really worried about: the dry cask storage units, a cluster of concrete cylinders sitting next to the plant.

"We should not be able to be here. If somebody had bad intent, there's the dry casks right there," she said.

She's worried that the casks, which contain radioactive material from the reactor, are too easily accessible and unprotected. An attack on the casks could result in a nuclear explosion.

"You could jump over here and be over there in two minutes," she said. She pointed out a lack of security surveillance of the road passing by the storage casks.

To add to existing concerns, Entergy is now looking to sell the power plant to Holtec, a company that specializes in nuclear decommissioning — basically, shutting nuclear power plants down. It’s the same company that manufactured the dry cask storage cylinders that Turco pointed out. The company claims that it can decommission Pilgrim Nuclear in less time and for less money than Entergy is able to.

"Holtec bring decades of experience managing spent nuclear fuel, as well as decommissioning nuclear power plants, so they are much more prepared to do this work, they have the expertise we currently do not have," said Michael Twomey, vice president of external affairs at Entergy.

But whether it’s Entergy or Holtec that will decommission the plant, the town of Plymouth will have to deal with the consequences. Melissa Arrighi is the town manager, and she said the plant’s closing is largely seen as something positive.

"I think there was relief on the mind of many people who had been worried, because the plant had some occurrences in the last few years that made the town worried, and some residents actually scared," Arrighi said.

Plymouth doesn’t depend on a lot of tax revenues from Entergy, so financially, the town feels ready for the closure. But Arrighi is worried about the land the plant sits on, 1,600 acres of valuable real estate overlooking Cape Cod Bay — land that right now is destined to be a holding place for nuclear fuel for 60 years or more.

"I think we're resigned to that long term that we've heard about for so long," Arrighi said.

The decommissioning company Holtec has talked about the possibility of moving the fuel offsite, but Arrighi doesn’t think that’s a future the town can depend on.

"Holtec sounds very confident, but I'm going to reserve judgement until we actually see what happens," she said.