A Nuclear Regulatory Commission investigation into a control room electrical fault last fall and other issues at the Palisades nuclear plant has resulted in three formal violations and enhanced scrutiny from the agency.On Tuesday, the NRC announced a yellow finding related to a Sept. 25 electrical fault. Work on an electrical panel caused half of the control room indicators to malfunction and tripped the reactor. According to the NRC, “This made the reactor trip more challenging for the operators and increased the possibility of a serious event occurring.”The agency also issued two white findings related to a service water pump failure last August caused by coupling cracking that the NRC said the plant failed to address after experiencing similar problems in 2009. All of the nation’s power reactors are categorized in the NRC’s “Action Matrix,” and the findings at Palisades prompted the agency to move it into the matrix’s degraded safety cornerstone column. Consequently, the plant will receive more inspections and oversight from the agency.Entergy operates the plant near South Haven, Mich. It uses a single 778 megawatt Combustion Engineering pressurized water reactor first licensed in 1971, according to the NRC.