Fast-breeder said realistic no more

Kyodo

A panel of experts reviewing the nuclear fuel cycle policy in light of the Fukushima crisis has agreed that while a fast-breeder reactor has advantages, from a technology viewpoint it can’t be considered a realistic option for the next 20 to 30 years.

The nuclear fuel policy involves reprocessing spent fuel to produce plutonium that can be reused to produce electricity.

The subcommittee of the Japan Atomic Energy Commission said in a draft document summarizing its discussions that two viable options during the next few decades would be to not reprocess spent nuclear fuel, and to recycle plutonium-uranium mixed oxide fuel, or MOX fuel.

The former option is called the “once-through” cycle, in which uranium fuel is used in nuclear reactors just one time and disposed of by burying it in the ground. In the latter option, MOX fuel is manufactured from plutonium recovered from spent nuclear fuel and used in ordinary reactors.

Japan has used MOX fuel in reactors, and the government has said the commercialization of a fast-breeder reactor would be expected to drastically improve the efficiency of nuclear fuel resource utilization. At present, the only such reactor, the accident- and scandal-prone Monju prototype in Fukui Prefecture, remains shut down and facing a bleak future amid mounting safety fears and budgetary concerns.

Tatsujiro Suzuki, chairman of the subcommittee, told a news conference Thursday that he thinks a fast-breeder reactor has “extremely advantageous characteristics from a long-term viewpoint.”

But he added there are uncertainties about the reactor’s development, and the draft document said other technologies could serve as alternatives.

The document also said the “once-through” cycle has high economic efficiency, while MOX recycling has high efficiency of uranium use.

The subcommittee plans to come up with policy options on nuclear fuel cycles that are expected to be reflected in discussions to decide the country’s overall energy policy.