Fukushima events

In France, after the Fukushima event, and as per the L Autorite de surete nucleaire (ASN) or the French Nuclear Safety Authority requirement, Electricity de France (EDF)... 

AHWR design is found to be robust for long station blackout (LSBO) as well as LSBO with partial loss of heat sink based on analysis of postulating several scenarios relevant to the Fukushima event. 

The Fukushima event heightens awareness of black swan or long-tail events, as discussed in Chapter 8. 

German National Academy of Sciences Leopoldina - National Academy of Sciences. Energy- and research-policy recommendations following the events in Fukushima. 2011. Available from http //www.leopoldina.org. 

Fukushima, T., Shirayama, Y. and Kuboki, E. (2000) The characteristics of deep-sea epifaunal megabenthos community two years after an artificial rapid deposition event. Publications of the Seto Marine Biological Laboratory, 39, 17-27. 

He is equally scathing about estimates of consequence. He believes that the consequences of events such as Deepwater Horizon or Fukushima—Daiichi will always be much more serious that estimated in the risk management models. 

In Chapter 1, it was noted that the Fukushima-Daiichi catastrophe provides a good example of Common Cause events the earthquake knocked out the primary cooling pumps, and the tsunami then knocked out the backup pumps. Copies of the Fukushima-Daiichi P IDs (Piping and Instrument Diagrams) are not available. Therefore, for the sake of discussion it is assumed that there are two sets of pumps three operating pumps (Ol, 02, and 03) driven by electricity and two backup pumps (B1 and B2) that are diesel-powered and that do not require electrical power. The Fault Tree for this assumed set up is shown in Figure 15.28. It consists entirely of and Gates. 

The second event was the Fukushima earthquake and tsunami, which forced the decommissioning of four nuclear power stations and halted the operation of almost all 50 other stations in Japan in mid-2012 because of a campaign against nuclear power plants and other antinuclear demonstrations around the world. Therefore, we are forced to depend more on thermal power generation through coal burning, which emits the most CO2 of any method of electric power production. The production of CO2 is expected to increase in the future. 

March 11,2011, Fukushima, Japan. A near-record earthquake with a 9.0 magnitude occurred off the northeast coast of Japan. It produced a nearly 50-foot high tsunami that flowed over protective walls, killed more than 19,000 people and destroyed or collapsed more than one million buildings. The nuclear reactors at Fukushima withstood the earthquake, but not the tsunami. Within three days, three reactor cores had melted. Within a few months, the plant lost other parts also. The event cause a release of large amounts of radiation. Officials evacuated more than 100,000 people from their homes to prevent radiation sickness. The cleanup continued for many months. 

The Institute of Nuclear Power Operations wrote an interesting addendum to their INPO 11-005, Special Report on the Nuclear Accident at the Fukushima Daiichi Nuclear Power Station. They go on to discuss some of the lessons learned from the black swan event. Many of the lessons learned are heavily related to nuclear-specific design and operational issues however, here are some that have more universal application and again are themes that we shall see throughout this book (INPO, 2012) ... 

Behaviors prior to and dnring the Fukushima Daiichi event revealed the need to strengthen several aspects of nuclear safety culture. It would be beneficial for all nnclear operating organizations to examine their own practices and behaviors in light of this event and use case studies or other approaches to heighten awareness of safety culture principles and attributes. 

Emergency response is important for any event. The Fukushima Daiichi disaster is an example of how a natural disaster created a massive safety accident. Chapter 4 details how emergency management is part of the SMS. 

You don t need to be reminded of the most recent nuclear accidents, principally Fukushima Daiichi in Japan in 2011. After the Three Mile Island accident in the late 1970s, the U.S. Atomic Energy Commission developed WASH 1400, The Reactor Safety Study. The WASH 1400 report laid the foundation for the use of probabilistic risk assessments (called probabilistic safety assessments in Europe). According to Henley and Kumamoto (1991), probabilistic risk assessment involves studying accident scenarios and numerically rank[ing] them in order of their probability of occurrence, and then assess[ing] their potential consequence to the public. Event trees, fault trees, and other risk-consequence tools are applied in developing and studying these scenarios. These techniques are extremely useful for the engineer but very expensive. The nuclear industry has been the leader in probabilistic safety analyses. 

One illustration of extended horizontal couplings was provided by the earthquake that hit Japan on 11 March 2011. While the interest for many reasons has focused on the consequences that the earthquake and the following tsunami had for the Fukushima Daiichi nuclear power plant, there were other consequences as well. Japan s leading automaker, Toyota, has a large presence in northern Japan, and was therefore most affected by the quake. The earthquake did not just damage a number of Toyota s own production sites, but also effectively disrupted the supply chain. Modern manufacturing methods require a steady flow of parts and materials from upstream sources to arrive just in time and any disruption of this can be fatal. This dependence makes it necessary to extend the boundary of the system to include events that happen upstream, in order to insure against disruptions as far as possible. It may similarly be necessary to extend to boundary to include what happens downstream, in order to prevent unwanted consequences of the operations. 

To date the world has seen the occurrence of a number of major nuclear reactors accidents (rated 5 and above on the International Nuclear Event Scale by the International Atomic Energy Agency). For Fukushima we consider one accident, although more than one reactor was involved, to ensure the list is made of independent accidents. Assuming seven accidents, the historic world average rate of Scale 5-t accidents is 4.75 x 10 " Scale 5+ acci-dent/annum (Table 37.2). 

Second, the loss of primary coolant at the Fukushima—Daiichi reactors resulted from the use of pressurized water coolant. An LFR with guard vessel would not suffer a loss of primary coolant, even in the event of a failure of the reactor vessel. 

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