Criticality accident detectors are required for all operations involving fissile materials in which a criticality accident can occur and cause personnel to receive unacceptable exposure to radiation (ANSI/ANS 8.3‐R2012). Recently, the U.S. Department of Energy Y‐12 National Security Complex tested six criticality accident detectors and eight Portable Radiation Detection Instruments (PRDIs) to verify their performance under actual criticality conditions. The tests were performed by Los Alamos National Laboratory using the Godiva critical assembly located at the National Criticality Experiments Research Center at the U.S. Department of Energy Nevada National Security Site. All six criticality accident detectors and eight Portable Radiation Detection Instruments passed the performance tests. The test results provide reasonable assurance that the Y-12 criticality accident detectors and PRDIs will detect a criticality accident and warn workers to evacuate the area to minimize their exposure to this life-threatening hazard.