nuclear undone
  • blog
  • about
  • contact

undo your thinking

listen to the facts

absorb new ideas

Should Japan Move to Probabilistic Analysis Methods for Nuclear Industry?

6/18/2014

0 Comments

 
Picture
An employee measures using a dosimeter at the central operating control room of the No. 1 and No. 2 reactors at Fukushima Daiichi nuclear power plant in Fukushima.
By Wes Deason

Three years after the tsunami that caused the meltdown at Fukushima Daichii, Japanese academics shared concern over the continued use of “absolute safety” measures in the country. The methods used by the Japanese Nuclear Regulatory Authority (NRA) rely upon the concept, where historical earthquake data is used to establish a standard which all nuclear plants are required to meet. However, these methods are considered to be excessively conservative, and may put several nuclear plants at risk of shutting down if they prevail.

Professor Koji Okumura of Hiroshima University explained that the NRA seismic activity standards do not allow for the use of probabilistic analysis methods, even following the accident at Fukushima Daichii. This differs from the United States, where probabilistic analysis methods have been used by the U.S. Nuclear Regulatory Commission (NRC) for characterizing seismic behavior since 1997.

The benefit of probabilistic analysis methods is that they allow for a technical judgment to be made on the effect of an uncommon hypothetical situation, such as an earthquake, on nuclear plant operation. Characterization of these uncertainties allow for regulators and plant operators to distinguish between real plant safety issues and issues which just appear to be unsafe. They may also allow for more economic operation of plants, as safety features can be applied where they are needed most.

Much of the panel discussion, which took place at the 2014 American Nuclear Society (ANS) Annual Meeting, focused on the technical aspects of characterizing the uncertainty of seismic behavior in regions which lack detectable faults, also called diffuse or background seismicity regions. Experts from the NRC encouraged Japanese regulators to embrace probabilistic analysis methods in order to prevent getting blindsided by more likely but smaller scale incidents that may occur.

They also recommended Japanese regulators to pursue establishing a committee of global experts. These experts could then assist in interpreting seismic analysis results and their effect on the design and operation of nuclear plants. This committee would follow the example of the Senior Seismic Hazard Analysis Committee, established by the NRC in the 1980’s.

0 Comments



Leave a Reply.

    Picture

    Archives

    January 2017
    December 2016
    November 2016
    October 2016
    August 2016
    June 2016
    May 2016
    February 2016
    January 2016
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013

    Categories

    All
    American Nuclear Society
    Climate Change
    Diversity In Stem
    Energy
    Environmentalists
    Fuel Cycle
    I'm A Nuke
    International
    IYNC
    Navy
    Nonproliferation
    Nuclear Energy
    Nuclear Energy
    Nuclear Engineers
    Nuclear Technology
    Policy
    Radiation
    Reactors
    Science Education
    Sustainability
    UAE
    Women In Engineering

    RSS Feed


    Follow on Bloglovin
Powered by Create your own unique website with customizable templates.
Photos used under Creative Commons from Idaho National Laboratory, Jim.Richmond, Idaho National Laboratory, IAEA Imagebank