Resumen
This paper analyzes a reactivity management event at a US NPP (Nuclear Power Plant) which resulted in the unrecognized inadvertent passive shutdown of the reactor. The event was not documented in the NPP?s Corrective Action Program by the operating crew involved and was not reported by the utility to the United States Nuclear Regulatory Commission (NRC, the nuclear regulatory authority) or to the Institute of Nuclear Power Operations (INPO, the industry consortium to which the plant is a member and is expected to report significant operating experience). This paper provides: (1) a description and analysis of the event, (2) analysis of the plant?s response to the event and the shortcomings of relying on corporate self-regulation, (3) analysis of potential shortcomings in the US nuclear industry?s Operating Experience collection efforts, (4) analysis of the regulatory challenges pertaining to the response to events that clearly are adverse to the nuclear Safety Culture yet do not clearly violated any regulations, and (5) the difficulties faced by the regulator with regard to discriminating between and making judgments of ?gross negligence? and ?dereliction of duty?. The description of the event, the organizational responses to it, and the listed references contain valuable examples of shortcomings involving Reactivity Management, nuclear Safety Culture, Nuclear Criticality Safety, Corporate Oversight, and Regulatory Agility.