Fukushima Five Years Later: EPRI Software Helps Improve Accident Response Guidelines

Neil Wilmshurst

This week is the fifth anniversary of the accident at Fukushima Daiichi nuclear power plant. To mark the event, we'll be sharing observations from leaders around the nuclear energy industry all week long on how the U.S. has absorbed lessons learned from the accident to make safe nuclear plants even safer. Today's contribution comes from Neil Wilmshurst, Vice President and Chief Nuclear Officer at the Electric Power Research Institute (EPRI).

Even as the events at Japan’s Fukushima Daiichi nuclear plant were unfolding, the U.S. industry began analyzing the situation and compiling data that would inform the industry’s lessons learned.

The Electric Power Research Institute’s Modular Accident Analysis Program (MAAP) software analyzes the progression of events during an accident. It captures many possible outcomes in a short timeframe. Unlike other codes, MAAP runs faster than accidents progress so it can actually guide emergency responders. Now in its fifth version, the tool has informed changes to industry guidelines that plant operators use to respond to accidents.

Because of Fukushima Daiichi’s rapid power loss, there is virtually no plant data from the accident’s early hours, data critical to understand the incident’s progression. MAAP filled in many data gaps, leading to critical lessons to help the global nuclear industry improve plant design and accident response guidelines.

One lesson from MAAP: Plant operators need a detailed strategy for using portable equipment, such as pumps to inject cooling water into reactors. Portable equipment strategies should buy time for plant operators to retrieve the equipment. For boiling water reactor nuclear plants such as Fukushima, this might involve devising a way for the plant’s existing reactor core isolation cooling system to function temporarily after a loss of power.

Nearly all U.S. companies that operate nuclear plants use MAAP analyses to develop the portable equipment plans they submit to regulators. Lessons from the MAAP Fukushima analyses have been incorporated into the industry’s severe accident management guidelines. That helps reactor operators prepare for and navigate potential accidents.

Comments

Activists' Claims Distort Facts about Advanced Reactor Design

Below is from our rapid response team . Yesterday, regional anti-nuclear organizations asked federal nuclear energy regulators to launch an investigation into what it claims are “newly identified flaws” in Westinghouse’s advanced reactor design, the AP1000. During a teleconference releasing a report on the subject, participants urged the Nuclear Regulatory Commission to suspend license reviews of proposed AP1000 reactors. In its news release, even the groups making these allegations provide conflicting information on its findings. In one instance, the groups cite “dozens of corrosion holes” at reactor vessels and in another says that eight holes have been documented. In all cases, there is another containment mechanism that would provide a barrier to radiation release. Below, we examine why these claims are unwarranted and why the AP1000 design certification process should continue as designated by the NRC. Myth: In the AP1000 reactor design, the gap between the shield bu...

What Happens During a Refueling Outage?

You may have noticed over the past few weeks that a number of nuclear plants are shut down for refueling outages or are resuming operations after just returning from one. This type of routine outage usually occurs in the spring or fall when electricity demand is low so that nuclear reactors can replace about one-third of the spent fuel rods with new fuel and conduct other routine maintenance and repairs at the plant. To get a better sense of how refueling works at a nuclear energy facility, I spoke with Marcus Nichol, NEI’s senior project manager for used fuel storage and transportation, and asked him to explain the basics. Why does a nuclear plant need to replace one-third of its fuel? Nichol: The main purpose of a refueling outage is to replace older fuel that is depleted—meaning it can no longer efficiently produce energy from nuclear fission reactions—with new fuel. This “used fuel” has typically been used in the reactor for four-and-a-half to six years before it is pe...

How Much Land Does Nuclear, Wind and Solar Really Need?

Not too long ago, we reviewed a report that looked at nuclear energy (and other energy sources) as biodiversity agents. This had to do, in part, with the amount of land a facility needs to function. Nuclear energy and fossil fuel plants use relatively little, wind farms and solar arrays quite a lot of land . Based on an objective and transparent analysis of our sustainable energy choices, we have come to the evidence-based conclusion that nuclear energy is a good option for biodiversity conservation (and society in general) and that other alternatives to fossil fuels should be subjected to the same cost–benefit analyses (in terms of biodiversity and climate outcomes, as well as sociopolitical imperatives) before accepting or dismissing them. Writer Barry Brook, who collected 75 scientists to endorse his paper, is interested in land use as it impacts flora and fauna. Biodiversity concerns do not get as much play as they might – and, when they do, it annoys many when land is withdraw...

NEI Nuclear Notes

Search This Blog