Nuclear Regulation Authority probes faults beneath Monju reactor


A team of experts from the Nuclear Regulation Authority on Wednesday began a two-day inspection of faults beneath the Monju fast-breeder nuclear reactor in Tsuruga, Fukui Prefecture.

The team will assess whether the eight crush zones are active faults. Under Japanese law, reactors are not permitted to be built above active faultlines.

The Monju reactor’s future has been in limbo for some time. In late May, the Nuclear Regulation Authority ordered the Japan Atomic Energy Agency not to restart the reactor and instructed the company to improve its safety measures. The trouble-plagued next-generation test reactor has been cited for numerous safety violations.

Monju uses plutonium fuel instead of conventional uranium and produces radioactive substances that can be reused as fuel. After nearly 50 years in the works, the reactor is still struggling to get online.

The previous government tried to terminate Monju under its nuclear phase-out plan, but Prime Minister Shinzo Abe’s government quickly reversed course as it pushed to restart commercial reactors that have been idle since a March 2011 earthquake and tsunami triggered a nuclear disaster at the Fukushima Daiichi plant.

Nuclear Regulation Authority chairman Shunichi Tanaka has said that Monju’s operator lacked a “safety culture” and deserved severe action.

Japan built Monju as a “dream reactor” to fulfill its energy needs, with the reactor meant to be a centerpiece of a self-sustainable fuel cycle. To complete the cycle, Japan has been building the Rokkasho fuel recycling plant in northern Japan to extract uranium and plutonium from spent fuel and fabricate hybrid fuel made from the two radioactive elements.

But with both Monju and Rokkasho having technical problems, Japan has built up a large stockpile of plutonium extracted overseas and at home, causing international proliferation concerns.

Monju successfully generated power using MOX — mixed oxide fuel, a mix of uranium and plutonium — in 1995, but months later, a massive leakage of cooling sodium caused a fire. Monju had another test run in 2010 but stopped again after a fuel exchanger fell into the reactor vessel.

Wednesday’s inspection by the Nuclear Regulation Authority is the fourth at a nuclear power plant in Japan this summer.

Only two of Japan’s 50 reactors are currently online, but four utilities—-Kyushu Electric Power Co, Hokkaido Electric Power Co, Shikoku Electric Power Co and Kansai Electric Power Co—have applied to restart 10, subject to approval by the Authority.

Japan Today/Reuters

  • -2

    Jeff Ogrisseg

    The NRA will find something, then Japan Atomic Power will come around later and dispute the findings. The University of Tokyo screwup that was revealed this spring -- Ooops! Turned out it was a concrete pillar! -- shows you how much these whiz-bang "experts" don't know.

    This is just the NRA trying to justify its own existence.

  • 6


    The reactor is a massive very expensive failure which has only managed to generate about one hour of power. A massive lack of safety standards and safety inspections including essential items. Way pass it sell by date and should now be decommissioned which several gov't's have stated they will but never do.

  • 1


    what does a Nuclear Regulation Authority know about geology?

  • 0


    @gogogo Maybe they have geologists working with them?

  • 2


    "The team will assess whether the eight crush zones are active faults. Under Japanese law, reactors are not permitted to be built above active faultlines."

    No, Japanese law, or at least the system, allow you to build above fault lines so you as you don't willingly admit they are there to begin with. You can admit it after a plant has already been built, claiming you don't recognize your own signature on the map showing the fault line, and/or you can admit it after a disaster... just not BEFORE. Oh, and you need the proper bribes.

    In any case, why are they still flogging this dead horse? What, do they want to spend a few trillion more for 6 more minutes or so of power?

  • 3


    Well, back in May of this year, seismologists said the plant was built on an active fault line, so I guess it now depends on how much it costs to see the data differently. It's a good time to be a seismologist, I guess.

  • 0


    Who is actually worried about the stockpile of Japanese plutonium and nuclear proliferation? Other than pro-Monju voices from the nuclear village? India/ Pakistan, Iran and some other countries are the main worries.

  • 0


    Who is actually worried about the stockpile of Japanese plutonium and nuclear proliferation?

    With Abe in control who wouldn't be worried about the stockpile of Japanese plutonium and nuclear proliferation?

  • 1


    Crazy days ! ! ! I just hope a major earthquake doesn't take out another Nuclear Plant.

  • 0


    I think the trouble started when the named the plant after the fuel. The name is too close to Mondai (problem) and been a mondaiji (問題児) (problem child) every since. Maybe the name is more appropriate than PNC knew.

Login to leave a comment

Law School: Information Session with Mock Class

Law School: Information Session with Mock Class

Temple University, Japan CampusContinuing Education / MBA

March Live Music Schedule at Dubliners'

March Live Music Schedule at Dubliners'

The Dubliners Irish PubBars

Special Offers

in Japan

Search the Largest English Job Board in Japan.

Find a Job Now!

More in National

View all

View all

Japan Investment

Listings Updated Daily