Review the failure of Monju


Just as the government finally makes a belated decision to decommission the trouble-plagued Monju prototype fast-breeder reactor, it is seeking to pursue a successor project in order to keep alive its bid for a nuclear fuel cycle in Japan. What it should be doing first is conducting a thorough examination of why the Monju project ended in failure and holding an open discussion on whether the nuclear fuel cycle — in which Monju’s technology was supposed to serve as a core component — is still a practical and feasible option for this country.

The formal decision to decommission the nation’s sole prototype fast-breeder reactor in Tsuruga, Fukui Prefecture, was long overdue. Billed as a dream nuclear reactor for resource-scarce Japan because it produces more plutonium than it consumes as fuel, Monju first reached criticality in 1994, but it has been mostly offline after it was hit by a sodium coolant leak and fire in December 2015. Its trouble-prone operator was judged by the Nuclear Regulation Authority as unqualified to run the facility, but the government has been unable to build a new viable regime to restart its operation.

Despite the injection of more than ¥1 trillion in taxpayer money, Monju was in operation for a mere 250 days over the past 22 years, and never reached 100 percent of its output capacity. It is estimated that restarting the reactor under the updated safety regulations will take at least eight years — a process that, including acquisition of necessary data that will require an additional eight years, is calculated to cost at least ¥540 billion. The decision to decommission the reactor — which in itself would require at least ¥375 billion over 30 years — was inevitable.

The problem is that the government seems to be moving headlong to the next project for its stalled nuclear fuel cycle policy without carrying out a proper assessment of Monju’s failure — either from scientific viewpoints or policy perspectives. The government plans to compile by 2018 a road map for the domestic development of a demonstration fast reactor, which also consumes plutonium as fuel.

The government has long pursued a nuclear fuel cycle policy — in which spent fuel from nuclear power plants are reprocessed to extract plutonium for reuse as fuel — due to its efficient use of uranium resources. Monju was a facility in the second stage of development (from experimental to prototype, demonstration and commercial) of fast-breeder reactor technology — which was to be the core component of the policy. Still, the government says it will not review its nuclear fuel cycle policy. It intends to promote the use of plutonium-uranium mixed-oxide (MOX) fuel at conventional nuclear power plants — although MOX fuel is much more costly and its use remains low because the restart of nuclear plants idled since the 2011 meltdowns at Tokyo Electric Power’s Fukushima No. 1 plant has been proceeding at a snail’s pace.

What’s puzzling is the plan to pursue the development of a demonstration fast reactor, even after the failure of the Monju project. The government reportedly says that even without restarting Monju, the same level of technological knowledge and data for development of a demonstration reactor can be obtained through a joint project with France to develop an advanced sodium technological reactor for industrial demonstration (ASTRID) and by using the Joyo experimental fast-breeder reactor. Still, ASTRID remains in its design stage, and it is unclear how much of its cost Japan will be sharing. The government has yet to publicly explain how much the development of a demonstration fast reactor will cost and how it plans to pay for it.

A bigger problem is that the plan to move forward on a fast reactor development was formulated in a closed discussion among a small group of people with stakes in nuclear power. The plan was adopted at the Council on Fast Reactor Development, which was set up by the Ministry of Economy, Trade and Industry and includes as members the economy and trade minister, the education and science minister, the head of the Japan Atomic Energy Agency — which operates Monju — the chairman of the Federation of Electric Power Companies of Japan, and the president of Mitsubishi Heavy Industries, a major nuclear power plant maker. It is unacceptable that the future direction of the nation’s policy on nuclear energy and the decision to launch a costly new project are being made by a closed circle of interested parties without public discussions that reflect on Monju’s failure.

The government clings to its pursuit of the nuclear fuel cycle because if it gives up on the policy, spent fuel at nuclear power plants nationwide will pile up and exceed storage capacity, rendering the operation of those plants difficult. Still, the completion of a nuclear fuel reprocessing plant in Aomori Prefecture continues to be postponed amid a series of technical glitches and massive cost overruns, and the start of its operation remains nowhere in sight. Meanwhile, Japan’s stockpile of plutonium — reprocessed at overseas plants from the nation’s spent fuel and shipped back here — has reached 48 tons without a clear prospect for its consumption, creating concern from the viewpoint of weapons nonproliferation.

The government has yet to give a convincing explanation of why the pursuit of a nuclear fuel cycle is still relevant as it seeks to reduce the nation’s dependency on nuclear power and expand energy supply from renewable sources after the 2011 Fukushima crisis, which made it difficult to proceed with nuclear power generation in the same manner as before. The decision to end the Monju project should serve as a chance for the nation to rethink the policy itself and hold an open discussion on our energy needs and nuclear power.