PLYMOUTH, Mass. — Massachusetts Land Court recently ruled in favor of Entergy Corp. in a lawsuit brought by local residents seeking to overturn a zoning permit issued by the town in 2013 for a new nuclear waste storage facility at the Louisiana-based company’s Pilgrim Nuclear Power Station.

The lawsuit claimed the town’s zoning permit for Pilgrim’s independent spent fuel storage installation (ISFSI) violated local zoning laws that required the issuance of a special permit and a public hearing. Pilgrim’s ISFSI consists of a concrete pad and dry casks to store 40 years’ worth of nuclear waste indefinitely, out in the open, about 150 feet from Cape Cod Bay.

“Pilgrim’s poor operating record and the risks this failing nuclear reactor poses has been a long-term concern,” said plaintiff Diane Buckbee, an abutter. “Making sure that the nuclear waste is properly stored and that local residents have every opportunity to have a say in the permitting process would help us protect our property values. The court’s decision denying us this opportunity is very disappointing.”

The Cape Cod Bay Watch has kept a close eye on the power plant for years.

The case arose because community activists discovered that in 2012, Entergy had begun construction of the ISFSI without any zoning approval. Entergy was running out of storage space in its inside spent-fuel pool, which was designed to store 880 spent nuclear-fuel assemblies, but was storing more than 3,000.

To address the storage problem, Entergy built the ISFSI and began moving waste from inside the reactor building to the outside ISFSI in 2014.

There were two issues in the case: whether the plaintiffs who live within 2 miles of Pilgrim had established legal standing; and whether the multimillion-dollar ISFSI is an “accessory” to Pilgrim or whether it’s a new project requiring a new special permit.

On the issue of legal standing, the court found that the plaintiffs established the right to bring the case, because Plymouth zoning law is designed to protect property values. Two of the four plaintiffs’ homes abut Pilgrim, and the other two live within 2 miles of the power plant. Plaintiffs filed the lawsuit to protect the value of their homes from the negative impact of the ISFSI. They argued that the special-permit process would allow residents to request permit conditions, such as those recommended by the Union of Concerned Scientists, to minimize potential harm from a radiological accident at the site.

Three of the four plaintiffs testified at trial that the ISFSI decreased their property value in relation to other properties farther away from Pilgrim. The plaintiffs’ expert witness, an economics professor from Williams College, also testified that there would be a negative impact on plaintiffs’ property values.

However, the court found that the plaintiffs didn’t offer “credible evidence to support their claim that the presence of the ISFSI project, as opposed to the presence of Pilgrim generally, negatively affects their property values,” according to its April 4 ruling.

On the second part of the case, whether the ISFSI required a new special permit, the court ruled that a 40-year-old permit issued by the town in 1967 to Entergy’s predecessor, Boston Edison, for the construction of Pilgrim allowed Entergy to expand and add the multimillion-dollar ISFSI for outside storage.

The court acknowledged that ISFSI technology didn’t exist in 1967 and that the industry plan was to ship all of Pilgrim’s nuclear waste to a deep geologic repository offsite, or to reprocess it. The court relied in part on the town building inspector’s testimony that the concrete pad for the ISFSI is “accessory” to Pilgrim, and “comparable to installation of a driveway.”

The building inspector compared the nuclear-waste storage facility to other accessory uses allowed under the bylaw, such as swimming pools being accessory to a residential home.

Once Pilgrim’s operations cease, the court said it’s up to the town to “decide whether the principal use of the property has changed and whether the ISFSI project remains accessory to Pilgrim.”

The plaintiffs retain the right to challenge whether the ISFSI goes beyond the scope of the 1967 special permit.

The plaintiffs’ legal team, Kevin Cassidy, Margaret Sheehan and Genevieve Byrne, expressed disappointment with the decision, and noted that no decision has been made on a potential appeal.

“We believe our evidence established standing and that the 40-year-old zoning permit does not authorize this new multimillion-dollar project,” Sheehan said. “We applaud the plaintiffs’ courage and determination in following this case through to trial after three years of Entergy’s efforts to get the case dismissed.”

Pilgrim is scheduled to close by May 31, 2019, after which decommissioning the reactor and cleaning up radiological and other contamination will begin.