The stakes are $4 billion in nuclear fiasco costs.

On one side are Mid-Carolina Electric and 19 other coops who argue that Santee Cooper can’t legally charge their member owners for a nuclear power plant that never produced electricity.

On the other is their electricity supplier, Santee Cooper, which claims state law allows it to charge co-ops for its $4 billion nuclear debt.

If a judge rules against taxpayer-owned Santee Cooper, it could leave it no way to pay off the debt.

State lawmakers are seeking ways to sell or transfer management of Santee Cooper to protect ratepayers from nuclear debt they had no voice in running up.

The co-ops are suing with email, letters and memos of Santee Cooper executives obtained through discovery.

Santee Cooper spokeswoman Mollie Gore said a response to the lawsuit will be filed in 15 days.

The State newspaper reported their lawsuit alleges Santee Cooper executives:

• Publicly lied about nuclear completion dates that they privately considered unrealistic and unreliable due to lead contractor Westinghouse and other contractors’ failures to meet deadlines and control costs.

• Poured billions of dollars – many of them from co-op members – into the project while privately complaining about costs and delays, poor nuclear engineering and contractors who inaccurately reported performance and projections.

• Hid problems including harsh critical findings of a Bechtel Corp. analysis of the project while paying 70% of the construction costs.

• Signed a new 2016 contract to shift financial risk to Westinghouse even though Santee Cooper officials were aware this could force Westinghouse into bankruptcy and kill the project.

Bechtel analysts found that Santee Cooper and SCE&G officials knew in 2015 the project was failing and lied about it.

Other documents have revealed that both utilities executives knew about major problems 2 years earlier.

The co-ops say they found out about the Bechtel report only in 2016, months after utility executives hid a final, watered-down version.

Santee Cooper denied requests for the report in late 2016, the co-ops allege.