The Monju nuclear reactor, a fast neutron reactor cooled with liquid sodium, was built in Japan between 1985 and 1991 and achieved criticality, or the start of nuclear reactions, in 1994. Designed to be a model for the future of atomic energy, Monju aimed to recycle spent nuclear fuel and generate more fissile material than it consumed. However, despite its completion, the reactor operated for only 250 days over a 22-year period due to repeated technical and management failures. These included a sodium leak, a doctored video, an accidental drop of equipment, and thousands of uninspected components. Located in Tsuruga, Fukui prefecture, the reactor became a symbol of the difficulties in managing complex and high-stakes technological projects. In December 1995, shortly after its commissioning, Monju faced its first major accident when a leak of liquid sodium caused a fire. Sodium is highly reactive with air and water, which makes it a dangerous coolant. Although the fire was eventually controlled, the site operator was accused of hiding the true scale of the incident by showing a shortened video to authorities and the media. This led to a one-year suspension of operations in 1997. The Japanese government later stated that the project’s failure was due to "management issues" rather than a flaw in the reactor’s design itself. After a restart in May 2010, Monju stopped again in August 2010 when a fuel-handling device accidentally fell into the reactor’s vessel. In 2012, it was revealed that about 10,000 pieces of equipment had not been inspected as required, a number that later rose to 14,000 out of a total of 47,500. This prompted the Nuclear Regulation Authority to conclude that the safety culture at the Japan Atomic Energy Agency was lacking. No other industrial company was willing to take over the operation, indicating a loss of confidence in the project. In December 2016, after 22 years and only 250 days of actual operation, Monju was officially abandoned. The total cost of the project was approximately 9.5 billion dollars, with some estimates suggesting up to 8.6 billion euros were spent by the Japanese government. The decommissioning of the site, approved in March 2018, is expected to take 30 years and cost an additional 2.86 billion euros. The Monju story underscores the challenges of managing large-scale technological projects and highlights the critical role of organizational competence in ensuring their success.