Briefing to the NRC on Fukushima Lessons-Learned

August 8, 2012
Dave Lochbaum
Former contributor

On Tuesday the Nuclear Regulatory Commission (NRC) was briefed by two panels on the implementation of lessons learned from the Fukushima Daiichi nuclear accident. The first panel consisted of James Scarola of Progress Energy, Casey Pfeiffer of the Professional Reactor Operators Society, Christopher Paine of the Natural Resources Defense Council, and me.

The second panel consisted of five NRC senior managers: Michael Johnson, James Wiggins, Brian Sheron, Eric Leeds, and David Skeen.

I pointed out that Fukushima was not a surprise—steps had been taken to address earthquakes, tsunamis, loss of onsite power, severe accident management, and emergency response. Had any one of these steps not been limited by assumptions on the magnitude of the hazard they were intended to handle, there would not have been a Fukushima disaster. But because the same faulty assumption as to the magnitude of the hazard caused each step to come up short, the result was disaster.

I then discussed a number of areas where the NRC’s proposed lessons learned from that disaster fall short of protecting Americans. For example, documents show that the NRC’s top priority five days into the Fukushima disaster—at a time when three reactor cores were presumed to have suffered extensive damage and their containments seriously degraded, i.e., a worse situation than encountered at any time during the Three Mile Island accident—was not the reactor cores but the Unit 4 spent fuel pool.

And yet the NRC proposes doing little to lessen the risk from overcrowded spent fuel pools in the US. UCS advocates transferring the spent fuel from pools to dry storage. More than 400 fuel bundles were in dry storage at Fukushima yet received little attention because they posed no threat to any one during the accident.

Also, the NRC’s proposal to require high capacity makeup water systems for the spent fuel pools in event of loss of cooling or loss of water from a pool for many reactors can result in merely changing the cause of the disaster from a natural tsunami to one caused by human actions. All, not just some, of the emergency pumps needed to cool the reactor core are located in the basement of the same building housing these spent fuel pools. Thus, water that overflows or boils away from the spent fuel pool drains to the basement where it floods and disables the emergency pumps, a Fukushima replay.

The slides from my presentation to the NRC (also shown below) provide additional details on these and other points raised by UCS during the briefing.

20120807 ucs-nrc-fukushima-lessons from Union of Concerned Scientists