On February 16, 2021, the NRC issued a Notice of Violation to Purdue University for a Severity Level III problem involving two violations. The first violation involves the Purdue University Research Reactor operating at steady state power levels in excess of 12 kilowatts (thermal) on several occasions between October 31, 2019, and September 15, 2020, contrary to Purdue University Research Reactor License Condition 2.C.1. Specifically, the reactor was inadvertently operated at power levels greater than 12 kW(t) during this time due to nuclear instrument (NI) calibration calculation errors that caused the NIs to indicate reactor power levels that were approximately three times lower than actual reactor power. Therefore, when the licensee operated the reactor above 4 kW(t) (indicated power) several times between October 31, 2019, and September 15, 2020, the actual reactor power exceeded the maximum authorized power level of 12 kW(t). The second violation involves Purdue University’s failure to perform appropriate surveillance testing before considering the NI system operable following replacement of the NI system and detectors in 2019, contrary to Purdue University Research Reactor Technical Specification 4.2.g.