Three Republican members of the Senate Armed Services Committee contend that a case now before the Supreme Court could undermine federal policy about uranium and other assets that are critical to national security and defense.

The justices heard arguments Monday in an environmental case about a three-decades-old Virginia law that prevents mining of the largest deposit of uranium in the United States, in Pittsylvania County, in the southwest region of the state.

The case turns on the regulatory line between state and federal authority over the extraction and then further processing of nuclear materials. A mining company as well as the U.S. government argued Monday that Virginia does not have the authority to ban uranium mining based on radiation safety concerns.

In a brief filed earlier in the case, Sens. Tom Cotton of Arkansas, Ted Cruz of Texas and James M. Inhofe of Oklahoma also urged the justices to side with the mining company, because a decision that allows a state ban to continue would carry “far-reaching and serious risks” at a time when domestic production and development of uranium is at historic lows.

“In this case, local-based preferences threaten the implementation of uniform federal policy over uranium, a strategic national resource, at a critical time,” the senators wrote.

A lawyer for Virginia Uranium, Inc., argued Monday that Congress in a 1954 law established that the Nuclear Regulatory Commission regulates uranium mining for radiation hazards, while the states can regulate for other purposes.

Virginia’s ban on mining is actually motivated by radiation concerns about the next two stages in the mining process — milling the ore and the storage of waste rock called tailings — that are under the NRC’s authority, attorney Charles Cooper argued.

Congress in the law asked the courts to look at the purpose of a state law, Cooper said, so allowing Virginia to ban mining in order to stop milling and tailings would “make a mockery” of the federal regulatory structure.

And Noel Francisco, the solicitor general arguing on behalf of the United States, said allowing the Virginia ban without reviewing the state’s purpose would amount to “giving states a roadmap for undermining a multi-billion-dollar industry.”

But Virginia solicitor general Toby Heytens told the justices that Congress could have given the federal government direct authority over uranium mining — but did not. So, Virginia lawmakers retain the ability to ban mining regardless whether the purpose is radiological safety or something else.

“The Nuclear Regulatory Commission has literally no authority over source material until it leaves the ground,” Heytens said.

A majority of the justices expressed concern Monday about how federal courts would determine the purpose of a state law that banned uranium mining, but it was not clear how the court ultimately might rule.

The court will decide the case before the end of the term at the end of June. 

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