Nuclear reactor developer NuScale Power told investors on July 29 that the U.S. Securities and Exchange Commission had not told the company that it was the target of a current or prospective investigation, and "is unaware of any reason for such an investigation."

Then, just four days later, NuScale revealed in an SEC filing that it had been contacted by the agency seven months earlier and asked to provide information on its employment, severance and confidentiality agreements.