In early March 2013, Plymouth was hit by a nor’easter whose effects led to the shutdown of Bert’s Restaurant on Warren Ave in Plymouth. Here’s a video that shows the waves smashing into the building, whose elevation is only 6 about feet lower than Pilgrim Nuclear Power Station. The velocity zone (the area subject to wave action) for Bert’s Landing is 14 ft, while PNPS’s velocity zone is 16-18 ft depending on the location on site.
Nor’easters such as this are fairly common in Plymouth, as the history of Bert’s restaurant shows. In 1978, a nor’easter blew a boulder into Bert’s dining room, and in 1991 and 2010 windows and furniture were broken yet again by a nor’easter (Read: Nor’easter lands at Bert’s Landing – Wicked Local). Should weather events like these be of concern to the operation and safety of Pilgrim?
According to Entergy and the NRC, the answer is “no.” Pilgrim is officially designated as a “dry site,” meaning that it’s not considered to be vulnerable to flooding in a design basis event. Any storm with surges below 13.5 feet is not considered to be of concern, and Entergy and the NRC say they’re confident that a surge will never reach this height. However, this is contradictory to FEMA’s 17 foot velocity flood zone designation for Pilgrim. Even this is a conservative estimate when you account for a storm surge, wave height, and tides. Storm surges from a northeast storm are usually 6 to 7 feet. However, hurricane storm surges can be greater, as Hurricane Sandy, for example, caused a storm surge of 14 feet at the southern end of Manhattan, and about 12 feet in Rhode Island. But these figures do not include wave height. The “Perfect Storm” of 1991 generated waves that were up to 30 feet tall along the Massachusetts coast. If you keep in mind that high tide in Plymouth is usually 4.5 to 6 feet above MSL, then you’re looking at flooding that could surely affect such a site as Pilgrim. Sea level rise as a result of climate change is expected to add another 6 feet to the equation by the end of the century. Read more about storm risks →
One of the most concerning implications of all of this is the effect that a nor’easter might have upon Pilgrim’s dry cask storage facility, a permanent structure that will house spent nuclear fuel assemblies in concrete, steel-lined cylinders. These casks have two sets of vents, one at the top of the cask and one at the bottom, which use air circulation to prevent the spent fuel from overheating. However, if one of the vents is blocked, then the circulation will fail and the rods may overheat. Water from a nor’easter could block the bottom vent and cause such a situation. Read more about casks →
Because Entergy doesn’t believe that flooding is a problem, it is not taking every precaution necessary to make sure the casks are built and positioned safely. The pad that Pilgrim is constructing for its dry cask storage facility is being built at 24.5 feet above MSL, which, as we know, is not completely safe from flooding in an extreme weather event. Entergy owns 1,500 acres of property surrounding the power plant, but it chose to position its casks close to the reactor to save money that would have to be spent to build a new access road to the site.
Another area of concern that the video of Bert’s raises is the question of road access during a storm. As you can see in the video, the parking lot of the restaurant is completely flooded. Couldn’t this happen to streets along the shoreline that would have to be used during an emergency evacuation, which would likely occur in sync with a storm? The reason I say “in sync” is because a station blackout, which could be caused by a nor’easter damaging power lines or flooding underground power lines leading into Pilgrim, could cause a meltdown or spent fuel pool fire and explosion. Both the reactor and the spent fuel pool need electricity to cool their respective radioactive fission products from overheating. If electricity was lost, the diesel backup generators were made inoperable from flooding (as they were at Fukushima), and the roads to access backup pumps were made impassable from flooding, then a serious nuclear accident that would call for an evacuation could occur within hours, and the routes to carry out this evacuation would be made impassable, trapping Plymouth residents in the vicinity of radioactive releases. The fact that it would be raining during a nor’easter or hurricane would exacerbate the effect of the radiation release as well.
Entergy and the NRC should be prepared to face the worst-case scenario, not just what is likely to happen or has happened, because next time, it won’t just be Bert’s that shuts down for good – it could be all of Plymouth.
