A landmark transmission project in the Northeast is stalled, once again.

PJM Interconnection, the mid-Atlantic wholesale grid operator, has been trying to relieve congestion at Artificial Island, the cul-de-sac home of two nuclear power plants on the New Jersey side of the Delaware River.

When PJM launched the project in April 2013, it was the first “merchant” transmission project bid via a competitive solicitation under a 2010 federal rule. Delaware and Maryland quickly objected to PJM’s cost-allocation methodologies, and then participants cried foul over PJM’s selection process. The cost-allocation dispute was resolved and, eventually, LS Power was selected to build a 230-kV transmission line under the Delaware River to Delaware by offering to cap its bid at $146 million.

But in New Jersey, controversy continued as to where the new lines would connect to one of the nuclear plants. Public Service Electric & Gas was selected to upgrade the substations, but that work was not put out to bid. PJM chose PSE&G in part because the nuclear-related work involves high levels of security clearance.

PSE&G’s portion of the project originally involved expanding the substation at the Salem nuclear plant on Artificial Island. PJM came up with a cost of $137 million for the job, but PSE&G came up with a much higher number, $272 million. PJM and PSE&G planned to cut costs by shifting the job to the Hope Creek nuclear plant, which is farther from the water but offers less cramped working conditions.

PSE&G’s calculations for breaker clearing times were incorrect, however. Using inaccurate numbers could jeopardize the expected benefits of the project, so PJM earlier this month hit the pause button and embarked on “a comprehensive analysis” of the project, with a February due date.