The head of the Nuclear Regulatory Commission told lawmakers Tuesday that it was too early to tell whether her agency could finish a safety review of Yucca Mountain, frustrating Republicans who hoped the analysis would help push the nuclear-waste project forward.

NRC Chairman Allison Macfarlane, testifying before the House Energy and Commerce Committee, said the NRC was trying to determine whether it had enough money to complete the safety analysis, which was suspended amid uncertainty about Yucca Mountain's fate.

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