New York’s Indian Point nuclear power plant has just completed replacing about a third of Unit 3’s baffle bolts. This follows the replacement last year of roughly the same number in Unit 2. In both cases, the number of degraded bolts was higher than expected.
On March 13, Buchanan-based Indian Point Unit 3 entered its scheduled refueling and maintenance outage, which included an inspection of bolts on the baffle structure, which surrounds the nuclear fuel inside the reactor. Indian Point parent Entergy conducted this inspection of baffle bolts at Unit 3 two years ahead of schedule after engineers identified and replaced similar bolts on the baffle structure inside Unit 2’s reactor last year.
“We identified about 270 bolts at Unit 3 that needed replacing this year. That took several weeks to complete,” Nappi says. “We just completed that last week, and now we’ll finish up that process of putting new fuel in the reactor and then they can start Unit 3 back up.”
And that restart, Entergy spokesman Jerry Nappi says, will happen in the next two-to-three weeks. Entergy replaced 270 of 832 bolts. Baffle bolts hold in place baffle plates, which channel cooling water to the reactor core. Nuclear Regulatory Commission spokesman Neil Sheehan says the number of degraded baffle bolts at Unit 3 was higher than expected.
“The expectation was that there would be fewer degraded baffle former bolts because it’s a newer reactor and because of some other factors. However, they did find a significant number of bolts that had indications, which doesn’t represent actual degradation, it represents potential degradation,” says Sheehan. “So 256 bolts were found to have these potential flaws and would, therefore, be considered degraded.”
Paul Gallay is president of Riverkeeper, a party along with Entergy and New York Governor Andrew Cuomo to an agreement announced in January to close Indian Point by 2021. Gallay says the number of degraded baffle bolts is unacceptable.
“That’s why we have to vigilant even though there’s a closure order in place. And that’s why these reactors just had to close,” Gallay says. “No matter what your position is on nuclear energy, these reactors are too old, too dangerous and near too many people.”
“In general, we think the condition was better at Unit 3. It has to do with the fact when they were removing these bolts, few of them broke as they were being removed, and that’s a sign that the bolts were actually in better condition. Also, there were fewer missing bolt heads and lockbars, these bars that were used on the previous bolt design to hold them in place,” Sheehan says. “So, on the whole, even though there was a larger number of degraded bolts found at Unit 3, we believe the overall condition was better than that that existed at Unit 2.”
Sheehan says the exact cause for the number of potentially degraded bolts at Unit 3 is not yet known and, as was the case at Unit 2, some of the removed bolts will be sent to a lab for analysis. Riverkeeper’s Gallay says that doesn’t go far enough.
“Sure the reactors are going to close in three and four years from now but we have to make sure that they’re they are safe in the meantime,” says Gallay. “ So reactor 3 should not start up again until the Nuclear Regulatory Commission has done a full public evaluation of the cause of these damaged bolts.”
Here’s Entergy’s Nappi.
“Bolts lose their strength over time due to a number of factors, including heat and the hot water that surrounds them and the radiation from the nuclear fuel,” Nappi says. “And that’s why we do these inspections really so that we can continue to operate safely.”
Inspections uncovered the matter of degraded baffle bolts at Indian Point 2 during a planned refueling and maintenance outage in March 2016. Entergy had found degradation involving about 227 baffle bolts, which amounted to some 25 percent, the highest percentage ever found at a U.S. nuclear plant at that point. Since, says the NRC’s Sheehan, similar numbers have turned up elsewhere, including at the Salem nuclear plant in New Jersey. He says the NRC is considering how the baffle bolt issue could be impacting other nuclear plants and has been in discussion with plant owners on the matter.
“And we are looking towards a communication tool, perhaps some informational letter, that would share the experiences that they’ve now, they’ve seen at Indian Point and Salem in southern New Jersey and other plants to make sure that plant owners take the appropriate steps to ensure this is not an issue for their facilities,” says Sheehan.
Meanwhile, Entergy will perform another inspection of baffle bolts during Unit 2’s next refueling outage in early 2018 and during Unit 3’s final refueling outage in early 2019.