At least one nuclear power plant in the U.S. has had its computer systems breached in a cyberattack, ABC News reports. Federal authorities are investigating the hack, which is said to have not compromised any operational systems at the plant. The report does not identify which U.S. nuclear facility was involved in the breach. Authorities say only the business-associated side of the plant’s systems were compromised. According to the report, it’s not yet clear who was behind the attack or if the breach was associated with any other recent worldwide incidents.