Sunday, March 9, 2014

TEPCO 2011 - 2014: A Systemic Failure

Tokyo Electric Power Company, or TEPCO for short, is a utility serving roughly 29 million customers. No doubt such behemoth too big to fail provides challenges in organization and governance that are difficult to meet at best.

The company operates Fukushima Daiichi Nuclear Power Station with six reactors on the northeast coast of Japan 150 miles from Tokyo. In the aftermath of the Great Tōhoku Earthquake and Tsunami on March 11, 2011, the three operating reactors lost cooling, their fuel cores melted down, violent explosions devastated three reactor buildings, and vast amounts of radioactivity were released into the air and the Pacific Ocean, including isotopes of transuranic elements scattered as far as Tokyo (Sakaguchi and others, 2014; Yamamoto and others, 2014; Zheng and others, 2012). The ratios of the plutonium isotopes 240 and 239 Zheng and others (2012) determined in soil samples from the region were only slightly lower than those found in soil samples near the location of the 1986 Chernobyl reactor accident (Boulyga and Becker, 2002), providing strong evidence that the samples contained reactor fuel fragments from the stricken power station. Company and government were confronted with the greatest challenges of crisis management since WWII, exposing TEPCO’s crisis management to public scrutiny unprecedented in the company’s history. According to NHK WORLD (post with the title “Fukushima nuclear damage costs are mounting” published online Mar. 11, 2014, local time), the total cost of resolving the crisis will surmount 100 billion dollars.

Aerial view of Fukushima Daiichi Nuclear Power Station on March 24, 2011, after hydrogen explosions devastated the upper floors of the reactor buildings of Units 1 (background), 3 and 4 (foreground) in the wake of the March 11 earthquake and tsunami. Unit 4 was offline for inspection. TEPCO believes that hydrogen seeped into its building from Unit 3 via standby gas treatment system piping. The building of Unit 2 lost a blowout panel on the eastern side and was spared (courtesy

Without doubt TEPCO operators played a significant, heroic role in diminishing the impact of the radiological disaster in the first days and months after the accident. The operators took great personal risks to prevent explosions in the reactor vessels unleashing even more radioactivity rivaled only by the 1986 Chernobyl reactor disaster, despite the plethora obstacles posed by flaws in reactor design, the company’s negligence of safety upgrades and the resulting lack of emergency preparedness as last year's investigative NHK WORLD News video below aptly documents.

NHK portrays impressively how the human condition may fail in epic proportion confronted with the evolution of a complex accident with a multitude of events racing at differing pace on a multitude of levels, particularly because consequences of seemingly isolated incidents interacted and impacts compounded. For example, the ineffectiveness of the fire engines pumping water into the reactors to cool the heated fuel was exacerbated by the hydrogen explosion at one reactor destroying the engines lined up to deliver coolant to another. The siting of multiple reactors in close proximity only aggravated the severity of the crisis.

The documentary reveals accurately that the senior decision-makers at Fukushima were working under sensory overload. Under profoundly adverse conditions, the shift manager in the main control room of units 1 and 2 was challenged to oversee the shutdown of two reactors of different generation with differing emergency core cooling systems. It must have been difficult for even the best trained expert to keep focused on analyzing the progress of the divergent developments at such different systems.

It remains even more difficult to conceive how plant manager Masao Yoshida in the crisis center was able to keep abreast of the simultaneous crisis developments at six reactors, particularly when plant parameters were relayed by word of mouth. Because of a station blackout, including the loss of emergency diesel generators and battery banks, almost no power was available. Accurate plant parameters could not be collected in a timely fashion. Operators had to be sent into the reactor buildings to collect data and work valves  [TEPCO press handout with the title “Appendix 2: List of Documents concerning the Response Status at Fukushima Daiichi Nuclear Power Station and Fukushima Daini Nuclear Power Station (June 2012 version)” dated Jun. 20, 2012]. Ancillary observations like the intensity of the 'pig nose steam' exhausted from unit 1’s isolation condenser could not be adequately evaluated because of a paucity of training and experience.

Despite, the plant manager tried his best to understand the state of affairs based on the scant and, largely indirect, observations available to him. The faults do not lie with the operators on the site. The faults were systemic. TEPCO ill-appreciated instrumental and structural risk a priori, and therefore the company was ill-prepared to reign in this crisis.

When organizing crisis management, more attention ought to be paid to the limits of information processing of our mind. Understanding how the brain works may help implement decision-making in large organizations that enables us to adequately address a crisis like the Fukushima reactor meltdowns.

It may be informative in this context to examine how the brain's nerve cells process afferent input from sensory organs, how they interact and inform our actions. We may identify six fundamental principles of best practices in governance:

  • differentiation of intelligence,
  • redundancy, yet diversification, of lines of reporting,
  • distributed processing,
  • gain control,
  • feedback, and
  • plasticity.

Let us discuss some observations leading to these principles.

Parallel Pathways
During brain development, sensory input instructs form and function of the central nervous system (Melzer and others, 1994). Sensory pathways consist of multiple lanes crossing way stations of differing number that feed information from the sensory receptor cells in the periphery in a redundant, yet differentiated and distributed fashion to the nerve cells in the cerebral cortex, allowing for the parallel processing of diverse aspects of the data (Melzer and others, 2006a; Melzer and others, 2006b).

In addition, nerve cells embedded in our cerebral cortex known as interneurons terminate on other cortical cells that provide output. A subset, representing roughly a quarter of the nerve cells in our cerebral cortex, selectively dampens prolonged, excessive nerve cell excitation. Some, known as chandelier cells (Szentágothai, 1975), may suppress the activation hundred other cells in their immediate vicinity at great energy efficacy. Their output arbors branch into a dense overlapping mesh resembling the manifold arms of a chandelier. The arbors multiply terminate on target nerve cells at the location where the electrical signals that encode output information are generated [Inan and Anderson, 2014; demonstrative depictions of a chandelier cell were shown on the cover of Brain 122 (10), 1999]. Inhibitory interneurons control the gain of information, protecting nerve cell networks from excitatory overload without loss of functionality (Allison and others, 2000).

Feedback and Integration
Eventually, efferent feedback from nerve cells in the cerebral cortex modulate the activity of the nerve cells in subcortical way stations, enhancing some sensory inputs and diminishing others (Llinás and Steriade, 2006). After the comprehensive integration of the inputs, cortical cells arrive at activity-weighted decisions initiating a course of action (Jun and others, 2010; Lo and others, 2009).

Finally, one further strength of our brain is the plasticity of nerve cell connection. Nerve cell networks are able to reorganize their connectivity dependent on changes in input. Though less in maturity (Melzer and Smith, 1995) than in development (Melzer and others, 1993), this ability bestows a dynamic flexibility in response important to learning from failure and success.

Taken together, the intricate interactions between bottom-up feed-forward flow conveying diverse, differentiated aspects of sensory information and top-down feed-back filtering help us create an accurate image of our environment which, combined with the ability to mold nerve cell connectivity according to a changing world, results in the most appropriate actions available to improve our chances of survival. Therefore, redundancy, differentiation, diversification, control and plasticity constitute powerful tools for comprehensive information processing invaluable to adequate risk assessment and decision-making.

Based on the above principles of governance, even a simple creature like a toad performs adequately when confronted with its life’s challenges (see my post with the title "Professor Ewert's Toad" published online Dec. 21, 2011). As prove, amphibians have survived for 370 million years. Our brain may be more complex than the toad's brain. Yet it conforms to the same principles. The best practices that govern the toad’s actions as well as our own ought to apply to any human enterprise.

The Fukushima reactor disaster is entering its fourth year of mitigation. Complete decommissioning of the damaged reactors may take half a century. Roughly 90,000 former residents, who used to live in the vicinity of the stricken still nuclear power station, have not been able to return home permanently. The majority may not be able to move back for years to come (see Tetsuya Kasai's report with the title "About 60 percent of Fukushima evacuees cannot return home by 2017" published online by The Asahi Shimbun Mar.11, 2013). Many elderly abandoned the idea all together (see Sophie Knight and Antoni Slodkowski's report with the title "For many Fukushima evacuees, the truth is they won't be going home" published online by Reuters Nov. 11, 2013). Examining TEPCO’s performance in its efforts of mitigating the consequences of the disaster over the past three years leaves a lot to wish for.

Shadowing TEPCO's efforts at examining the causes of the accident over the past three years has been difficult at best. "Fukushima Ten Essays "compiles my own observations during the first year on the potential causes of the fuel meltdowns and the mishandling of the situation. My insights mainly draw on data collected.

The forensic investigation of the incident has made only little progress, though some crucial insights were quickly gained on the design weakness of the reactor's emergency fuel core cooling systems. It still remains ill-understood whether quake damage played a role in the failure to shut down the three operating reactors safely. A litany of design flaws and glaring operator inexperience and lack of training for emergency shutdowns during a station blackout have come to light, more because of investigative journalism than through the company’s own revelations.

Moreover, TEPCO failed to inform the public accurately about the radioactivity released from the station into air and water and the resulting doses of exposure to the public. TEPCO’s management of radioactively contaminated water has been inadequate.

A newly devised filtration system for radioactively contaminated water does not work. The company has set up a sprawling tank farm storing 13,000 tons, and tons still escape into the ground and the ocean every day.

In addition, the government has failed to provide rigorous oversight, seemingly ignoring the severity of crisis and overtly playing down risks and consequences to public health.

The removal of thousands of spent fuel rods has only begun late last year. To date, contractor Toshiba-General Electric accomplished to remove roughly one third of the fuel rod assemblies stored in the spent fuel pool of only one of the six reactors, that is from unit 4 which was shut down for inspection with the fuel unloaded into the pool at the time of the accident (see TEPCO handout with the title "Progress Status and Future Challenges of Mid-and-Long-Term Roadmap toward the Decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Station Units 1-4 (Outline)" released Jan. 30, 2014).

Clearly, the management of the Fukushima reactor disaster will leave a lasting blemish on Japan because principles of best practice, like those that successfully govern the brain, were not heeded.

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Thursday, March 6, 2014

The Differential & The Mind

Did you ever wonder how your automobile gets around the corner without burning tire rubber on the inside?

My wife found this timeless documentary below entitled “Around the Corner” produced by Jam Handy for General Motors almost 80 years ago. The film delivers the clearest and most wonderful demonstration how the problem can be solved. Our first generation 4Runner still works this way, unless we use the four-wheel drive.