Japan is missing its own deadline to find a new operator for a prototype nuclear power program that has failed to succeed in the two decades since it was built, threatening the resource-poor country's support of a technology other nations have abandoned.

The country's nuclear regulator in November demanded that a replacement for the government-backed Japan Atomic Energy Agency be found within six months for the troubled Monju fast-breeder reactor in Fukui Prefecture. Monju, which has functioned for less than a year since its completion more than 20 years ago, now faces the possibility of being scrapped.

The fast-breeder reactor — a cornerstone of Japan's atomic energy strategy dating back to the 1950s — uses spent nuclear fuel from other atomic plants and is designed to produce more fuel that it consumes. The reactor, named after the Buddhist deity of wisdom, has cost the nation more than ¥1 trillion and has barely operated since it first generated electricity in 1995, the year it suffered a sodium leak that led to a fire and subsequent attempted cover-up. Safety problems have continued to plague the facility ever since.