Environmental groups in Florida and North Carolina want utility regulators to reopen public hearings about a series of Duke Energy actions, from its failed nuclear projects to the merger with Progress Energy.

On Tuesday, a coalition led by Greenpeace and Florida Public Interest Research Group sent a petition to the Public Service Commission asking regulators to reconsider a settlement agreement with Duke.

That agreement has left the utility's 1.7 million Florida customers on the hook for $3.2 billion related to the broken and shuttered Crystal River nuclear plant and the canceled Levy County nuclear project.

And NC WARN, an environmental group in North Carolina, will ask during oral arguments Wednesday that North Carolina's Court of Appeals reopen hearings into the 2012 Duke/Progress merger. A large part of the concern in that case also focuses on the handling of the Crystal River and Levy nuclear projects.

The "two highly publicized nuclear project failures in Florida were among the billion-dollar-plus mistakes NC WARN urged the Commission to consider," said Jim Warren, NC WARN executive director. "Both of those have created upward pressure for the Duke holding company to maintain market value by bolstering profits in the Carolinas and other monopoly-captive states."

The Tampa Bay Times documented the troubles with the Crystal River plant and the failed Levy project in a series of reports for more than two years.

In February, Duke announced it would permanently close the Crystal River nuclear plant after the reactor's concrete containment building cracked during an upgrade project in 2009.

Then in August, the utility canceled the $24.7 billion Levy project as part of a settlement agreement regarding Crystal River.

The state PSC has approved the settlement, which resolves issues of who will pay for about $5 billion in costs related to the two nuclear projects. The settlement agreement puts most of the burden, about $3.2 billion, on customers. Insurance covered $835 million and Duke's shareholders will absorb the rest.

"It is time to stop taking advantage of consumers in Duke service areas," Dalyn Houser, of Florida PIRG. "The settlement was unjust and enraged many residents."

Kate Melges, of Greenpeace, said the PSC had not yet responded to their petition.

Cindy Muir, a PSC spokeswoman, said every Duke customer was represented and "after hearing from all parties … the commission agreed that the settlement agreement is in the public's best interest."

Ivan Penn can be reached at ipenn@tampabay.com or (727) 892-2332.