The Magnitude 9.1 Meltdown at Fukushima

by Nickolas Means

In the talk titled "The Magnitude 9.1 Meltdown at Fukushima," Nickolas Means recounts the catastrophic events surrounding the Fukushima Daiichi nuclear power plant during the March 11, 2011 earthquake and tsunami. The presentation highlights the sequence of technical challenges, decision-making processes, and the remarkable human elements in crisis management surrounding this nuclear disaster. Here are the main points discussed throughout the video:

Seismic Vulnerability: Japan's location on the Pacific Ring of Fire makes it prone to seismic activity. Historical warnings about tsunamis emphasize the risks faced by coastal constructions, including nuclear reactors.
Background of Fukushima Daiichi: Overview of the nuclear facility, its reactors, and the initial operating conditions before the earthquake struck.
The Earthquake: A comprehensive account of how the 9.1 magnitude earthquake triggered the crisis, highlighting the automatic safety measures that initially seemed effective.
The Tsunami and Equipment Failures: Following the earthquake, a tsunami wave much larger than anticipated inundated the plant, leading to the failure of backup systems that were supposed to maintain reactor cooling.
Emergency Response: The desperate measures undertaken by plant operators, including using fire engines to inject water into the reactors, showcasing remarkable bravery despite grave dangers.
Decision-Making Under Pressure: Detailed accounts of how plant director Masao Yoshida navigated the crisis, in contrast to Prime Minister Naoto Kan's challenging interference during the emergency.
Impact of Trust and Leadership: Emphasizes how trust in leadership influenced team dynamics and decision-making during the disaster response, with Masao Yoshida's staunch leadership style exemplifying effective crisis management.
Long-term Consequences: Discussion of the radiation released and the lengthy decommissioning process, highlighting that Fukushima involves one of the most significant nuclear events in history, dwarfing previous incidents in terms of radiation release despite not reaching Chernobyl's catastrophic levels.

The presentation concludes with critical lessons about leadership dynamics in crisis situations, particularly the importance of fostering trust and empowering operational teams to make crucial decisions in high-pressure environments. Means encourages re-evaluation of traditional organizational structures to support frontline workers better, underscoring that successful disaster management often depends on those closest to the action, not just those at the top of organizational hierarchies.

00:00:00 Ready for takeoff.

00:00:16 Thank you so much for being here. My name is Nickolas Means, and I am the lead of the engineering team at Sim. We are building tools to create and orchestrate slack-based access and authorization workflows. So, if you've got production system access challenges, come find me; we should talk.

00:00:30 I also co-host a podcast called 'Managing Up.' If you're into management stuff, you might be interested in it. Check it out at managingup.show. Today though, I'm here to tell you a story.

00:00:49 Dotted along the coast of Japan, usually a significant distance from the water, are stones like this one. These were left there by anonymous members of previous generations, and they all say something very similar: 'A home built high is children's relief. Remember the disastrous giant tsunami. Do not build homes below here.'

00:01:13 Japan is one of the most seismically active countries on Earth, built on the Pacific Ring of Fire. These stones make it obvious that they are also no strangers to tsunamis—massive ocean waves driven by earthquakes under the sea.

00:01:28 So, given the risk of tsunamis, you might be surprised by this map of nuclear power plants in Japan.

00:01:31 Every single one of them is right on the coast. Why is that? Well, when you picture a nuclear power plant, what pops to mind? It's probably something like this.

00:01:43 Credit to The Simpsons, this actually is a fairly accurate rendering of a two-unit pressurized water nuclear power plant. But the thing in this picture that you probably most closely identify with nuclear power is the two hyperboloid cooling towers standing tall over the rest of the plant.

00:02:01 Now, the funny thing about this is that there's nothing inherently nuclear about them. Every thermal power plant, whether nuclear or fossil fuel, needs a source of cooling. There are plenty of non-nuclear power plants that use hyperboloid towers and plenty of nuclear plants that use other kinds of cooling, such as mechanical draft arrays.

00:02:26 The post-war economic boom in Japan meant that by the 1970s, Japan was starving for electricity. They needed to build a bunch of nuclear power plants in a hurry and on a budget. One of the best ways to reduce time and cost was to build them on large bodies of water, to use the ocean as a giant heat sink so you don't need cooling towers at all.

00:02:41 And that's what Japan did over and over again. One of those plants on the sea with no cooling towers is Fukushima Daiichi, a six-unit boiling water nuclear power plant with a generating capacity of 5.3 gigawatts, owned and operated by the Tokyo Electric Power Company, or TEPCO. It's located right on the Pacific coast in Northeast Japan.

00:03:01 The reactors at Fukushima Daiichi went online between 1971 and 1979. All of them are boiling water reactors designed by General Electric in the United States. Unit 1 is a slightly smaller, older design than the rest of the fleet, while Unit 6 is a slightly larger, newer design.

00:03:15 March 11, 2011, started like any other day at the plant. Units 1, 2, and 3 were all running, as they say in the nuclear industry, hot, straight, and normal—running at full power, generating electricity. Unit 4 was offline, being refueled; Units 5 and 6 had both just finished being refueled and were undergoing testing in preparation for restarting.

00:03:35 But off the coast of Japan and the Earth's crust, trouble had been brewing for more than a thousand years. As the Pacific Plate continually subducts under the Okhotsk Plate that Tōhoku and the rest of Northeastern Japan sit on, potential energy builds up like a spring being compressed.

00:03:58 On March 11, 2011, at about 2:46 in the afternoon, that potential energy finally overcame the friction between the plates holding it back and became kinetic energy in the form of a magnitude 9.1 earthquake. The epicenter was about 45 miles off the coast, but subduction zone megathrust quakes like this one typically involve a rupture along hundreds of miles of fault line.

00:04:19 In this case, the fault line that ruptured roughly parallels the northern coast of Japan. The force of this rupture was such that northern Japan moved about eight feet closer to North America, and the tilt of the Earth's axis shifted somewhere between six and ten inches. We're not really sure. It was the most powerful quake to ever strike earthquake-prone Japan.

00:04:44 When the shaking started, Masao Yoshida, the director of Fukushima Daiichi, was in his office processing some of the paperwork that was ubiquitous in the TEPCO bureaucracy. Yoshida kept expecting the shaking to taper off, but it just got stronger.

00:05:05 For six long minutes, the ground shook. When it finally stopped, he knew there would be much to be done, so he threw on his hard hat, ran out of his office, fought his way through the mess right outside his door, and headed towards the plant's earthquake-proof Emergency Response Center.

00:05:24 The control room for Units 1 and 2 was in disarray right after the quake. As the shaking stopped, the operators immediately ran to the panels to start figuring out the state of the plant, calling out various measurements to Akua Azawa, the shift supervisor in charge of Units 1 and 2 that day. They were able to quickly see that the plant's automated emergency systems had done exactly what they were supposed to do.

00:05:49 Now, to understand what happens next, you need to know a little bit about how nuclear reactors work. So, let's do a crash course. The heart of any thermal power plant is the heat source—in a nuclear reactor, it's the uranium fuel rods that create the heat, generating a nuclear chain reaction. The fuel rods are contained in a pressure vessel and surrounded by water.

00:06:12 In a boiling water reactor, the water boils to steam at the top of that pressure vessel, and there are also neutron-absorbing control rods that can be inserted into the core to slow or stop the chain reaction. As water boils to steam at the top of the reactor vessel, it expands, and the energy from that expansion turns a turbine connected to a generator. This is how the plant generates electricity.

00:06:46 After the steam turns the turbine, it's directed into a condenser, where it turns back into liquid water, and then a circulation pump pumps that liquid water back into the reactor core. This is crucial because water that is constantly boiling to steam at the top of the reactor pressure vessel has to be continually replaced to keep the fuel rods from overheating.

00:07:09 At Fukushima Daiichi, like most nuclear plants, there are sensors to detect earth movement. When there's an earthquake, the reactor control system automatically scrams the reactor, putting the control rods all the way into the core and instantly halting the nuclear chain reaction. This happened exactly as it was supposed to in all three active reactors.

00:07:34 But the fuel in the core of a nuclear reactor gets so hot that cooling circulation must be maintained for days after shutdown to continue carrying this decay heat away from the fuel, so the fuel rods don't melt. Only once that cooldown has happened has the plant reached a safe state of cold shutdown.

00:08:00 That means the reactor's circulation pumps must be kept running, even though the core is shut down. That's a problem when a giant earthquake has severed your plant's connection to the electrical grid. Thankfully, the plant had redundant answers to this situation. First, each reactor has two enormous diesel backup generators, just one of which provides adequate energy to maintain circulation through the core.

00:08:20 These generators had all started automatically as soon as the plant lost its grid connection. In case the generators failed, each control room also had a bank of lead-acid batteries to power instrumentation and control valves for several hours.

00:08:34 Second, each reactor had a passive cooling mechanism that would function without any external power at all. In Unit 1, that took the form of an isolation condenser—it was a large tank of water open to the atmosphere. Steam from the reactor pressure vessel could be directed through a heat exchanger in the isolation condenser, where it would turn back into water and flow by gravity back into the pressure vessel.

00:08:56 With the water in the isolation condenser boiling off to steam in the atmosphere to release the heat, the isolation condenser could passively cool Unit 1 for three days before requiring more water to be added, without any human intervention at all. The slightly newer Units 2 and 3, because they're larger, have a different passive cooling system: the Reactor Core Isolation Cooling System, or RIC system for short.

00:09:29 The RIC system is a more complicated system but the basics are that steam from the reactor pressure vessel drives a pump that replenishes the water in the Reactor Core. It can be topped up from an external tank if the water level drops. When the backup generators kicked on at Fukushima Daiichi, these passive cooling systems all kicked into gear as well.

00:09:59 At this point, despite being without power from the electric grid, the plant was well on its way to a controlled shutdown. Everything was well in hand when the first tsunami warning went out a few minutes after the quake.

00:10:19 The initial prediction for the Fukushima area was just around 50 centimeters (18 inches). That would later be revised several times but never beyond the plant's 19-foot tall seawall. They made a precautionary announcement over the plant's PA system that there was a tsunami warning and that workers should move to higher ground just in case.

00:10:35 But that was the extent of their preparations. In reality, the largest of the three tsunamis heading towards the plant was more than 40 feet high and it was moving at 100 miles an hour when it arrived.

00:10:52 The operators in the windowless control room had no idea. They were shocked when one of the operators announced a new critical alarm at 3:37 PM: the diesel generators had tripped. A few seconds later, the overhead lights in the control room went out.

00:11:11 Then, slowly, randomly, panel by panel, their instruments all went dark. The constant warbling of alarms from the unhappy plant was replaced by an eerie silence. A few seconds later, Azawa broke the silence by shouting, 'Station blackout!'

00:11:37 They had no electricity at all—a situation never considered realistically possible in all of their emergency preparations. The reactors at Fukushima Daiichi are located on the 10-meter level, 10 meters above sea level.

00:11:56 The huge diesel backup generators, along with the power switching equipment and lead-acid backup batteries, were all in the basement of the auxiliary building on the 4-meter level. When the tsunami arrived and inundated their seawall, they were all destroyed.

00:12:19 The operators found themselves trying to operate three nuclear reactors that just minutes before had been generating over two gigawatts of power, with no instrumentation and no remote valve controls. Their immediate concern was Unit 1.

00:12:38 The operating manual for Unit 1 said that to protect the reactor's pressure vessel, the reactor's cooldown rate couldn't exceed 55 degrees Celsius per hour. About 20 minutes after the quake, the operators realized that it was cooling too fast, so they began cycling the isolation condenser in and out of service.

00:12:56 They had just cycled the condenser back off at 3:34 PM, three minutes before they lost power. The RIC systems in Units 2 and 3 would keep them under control for the time being, but Unit 1, because of unlucky timing, was completely without cooling.

00:13:18 Without coolant circulating to carry heat away, all of the water in the core would boil into steam. This causes a couple of problems. First, without cooling, the nuclear fuel rods will eventually get hot enough to melt.

00:13:42 Second, because water expands when it turns to steam, the pressure in the pressure vessel rises. If pressure gets high enough, it will eventually turn into a giant steam bomb and explode, spraying radiation into the environment.

00:14:02 Now, given Fukushima's location, that could make Tokyo uninhabitable for decades. That fact was in the back of everybody's mind. There were a few things they needed to do to get Unit 1 back under control, and they started working on them all at the same time.

00:14:28 First, they knew the instruments in the control room would work under DC power. So while one team began looking at wiring diagrams to figure out how to hook up electricity to all their instrumentation, another team went out and began harvesting car batteries from the cars parked around the site.

00:14:53 While they worked on that, another team began figuring out how to get water into the core of Unit 1. One of the first things plant director Yoshida did when the tsunami hit was to request fire engines from two nearby Japan Self-Defense Forces.

00:15:16 Now, this wasn't in the plant's emergency operations manual, but Yoshida predicted, correctly, that they would need some way to pump water, and fire engines were the first thing that came to mind.

00:15:33 Meanwhile, Katsuaki Hirano had just arrived at the Unit 1 control room. He was a shift supervisor from a different team. He wasn't scheduled to work that day at all, but he had made his way to the plant to help as quickly as he could after the earthquake.

00:15:56 He had the idea of using Unit 1's firefighting pipe network to route water to the core. He led multiple expeditions into the dark reactor building to manually turn the five valves necessary to route water from the fire pipes into the core.

00:16:18 Hirano and a partner returned from their final expedition around 9 PM. By 11 PM, radiation levels at the reactor building airlock were so high that further entry was prohibited by Yoshida, so it was fortunate that Hirano's expeditions were one of the first things the operating crew did.

00:16:39 The plant had three fire engines on site. One of them had been destroyed by the tsunami; a second couldn't get to Unit 1 because of tsunami damage to the roads. However, the third was just behind an electronic security gate at Unit 3.

00:16:56 But electronic gates don't work with the power out. By around two in the morning, they had finally broken the lock on the security gate, moved the fire truck into place, and had begun injecting water into the core of Unit 1.

00:17:14 Unfortunately, the water injection they were able to accomplish was very slow because of the pressure in the reactor vessel. Once they worked out how to hook up the scavenged car batteries to the instrumentation and control room, they found that pressure in the pressure vessel was significantly elevated—around two atmospheres.

00:17:36 The only way pressure this high would have been possible was if the fuel had begun melting down. So relieving the pressure and getting more water in was absolutely critical.

00:17:54 Thankfully, Yoshida had anticipated this as well and was already working on the necessary permissions to conduct venting. Now, this is exactly what it sounds like: venting likely radioactive steam from the pressure vessel of the reactor into the open atmosphere.

00:18:10 It was a worst-case measure to try to save the plant. Any atmospheric release of radiation required government permission, and that permission needed to come from this man—Naoto Kan, the Prime Minister of Japan.

00:18:37 As soon as an emergency had been declared at the plant, TEPCO sent a liaison to Kan's office, so he had already been briefed on the rising pressure at Unit 1. He readily gave permission for the vent.

00:19:02 As soon as the five-kilometer evacuation zone around the plant was evacuated—a process that was already underway at the plant—Azawa and his team had been working feverishly in rapidly deteriorating conditions to figure out how to vent the reactor.

00:19:23 Radiation levels were now high enough in the control room that being there required wearing full face masks with charcoal filters. If radiation was this bad in the control room, it would be terrible and dangerous in the reactor building.

00:19:50 They needed to figure out a way to vent the plant that would have staff in and out as quickly as possible. Back in Tokyo, Kan had finished his middle-of-the-night emergency press conference to announce the vent, and he was livid.

00:20:11 It was four in the morning. He'd given them permission to vent hours ago. 'Why the hell haven't they vented Unit 1 yet?' he exclaimed. Did they not know what was at stake? The TEPCO liaison in his office had explained the challenges the staff of the plant were facing.

00:20:30 But Kan decided he needed to find out for himself what was going on, so by 5:30 in the morning, the day after the earthquake, the Prime Minister and his entourage ran a helicopter on their way to Fukushima Daiichi.

00:21:02 At the Fukushima Emergency Response Center, there was panic and frustration over Kan's visit. Yoshida and his staff were now working feverishly to vent Unit 1, and now they had this to deal with.

00:21:21 On top of that, they had another problem to solve: they were running short of protective equipment. Now that the Prime Minister and his entourage were coming, they had to outfit them as well with their dwindling stocks.

00:21:45 Every time someone entered the radiation-shielded ERC, the face masks that they were wearing had to be discarded because as soon as the seal with their face was broken, it was contaminated.

00:22:05 It was decided that Kan would land at a nearby sports field, and that he and his entourage would be brought as close to the door of the ERC as possible in a mini bus, so that they wouldn't need to waste emergency equipment on them.

00:22:26 This was a clever solution. TEPCO VP Takami Muto was among the party to greet Kan's helicopter when it landed in Fukushima. Muto remembers offering Kan the standard Japanese greetings, very formal along the lines of, 'It's very kind of you to come, sir.'

00:22:42 Now, I'm sure he didn't feel this way, but that's what Japanese etiquette dictated that you say to the Prime Minister in a situation like this. Kan quickly responded, 'Why the hell haven't you vented yet?'

00:22:56 He proceeded to yell at Muto for the entire bus ride to the Emergency Response Center, remembering Kan saying repeatedly that he just wanted to know what the problem was, but then not listening at all. He seemed to only want to complain that staff weren't doing their jobs.

00:23:23 When Yoshida and Kan met in the ERC, Kan's first words to him were, 'What the hell is going on?' Rather than fight fire with fire, Yoshida calmly explained the situation in detail, and as he talked, Kan seemed to settle.

00:23:39 Finally, Kan asked, 'Well, when are you going to get the vent done? More than anything else, you must get the vent done.' Yoshida responded calmly again, 'We are, of course, doing everything we can. We have a suicide squad preparing to enter the radiation field now.'

00:24:02 Hearing that there were people willing to risk their lives to conduct the dangerous venting operation seemed to end the discussion. The actual meeting had lasted 20 minutes.

00:24:28 Azawa's crew had identified a pathway to venting that would require only opening two valves.

00:24:39 The valves were in two different areas of the reactor building, so they would send two teams of two into the radiation field. Under Japanese law, workers are allowed a maximum of 100 millisieverts of radiation exposure during an emergency, so everyone put on a personal dosimeter alarm.

00:25:01 They set it to go off at 80 millisieverts, agreeing to turn back immediately if it went off.

00:25:10 The first crew made their way to their valve on the second floor of the reactor building. It was huge, awkwardly placed at the end of a catwalk, hard to turn.

00:25:32 But they got it done and were back in the control room in 11 minutes without coming close to the 80 millisievert alarm. The second crew's valve was in a much more precarious position.

00:25:50 To help us understand, here's a photo of an under-construction Mark 1 containment structure. The valve was in the basement of the reactor building; if there had been core damage, it was likely that melted fuel would be sitting at the bottom of the pressure vessel, creating an intense radiation field at the bottom of primary containment.

00:26:10 As they made their way into the basement, the handheld radiation meter they carried was bouncing between 900 and 1000 millisieverts per hour—roughly enough to give them their max dose in about 10 minutes.

00:26:32 When they saw the meter stick at a thousand millisieverts per hour, the max it could read, they had to turn back. There was no way to know how strong the radiation fields they were walking into were with their meter maxed out.

00:26:52 When they got back to the control room, they found that they had received doses of 89 and 95 millisieverts, respectively. They were the first two workers to dose out and have to be evacuated from the site.

00:27:43 At nearly 10 in the morning, and the vent still hadn't been carried out, the operators had gone from elated at the success of the first crew to despondent at the situation the second crew encountered. But they didn't give up.

00:28:02 There had to be a way to vent. One group worked to see if a portable air compressor could remotely operate the pneumatic valve, while another tried to find a different route to the valve. At two in the afternoon, the reactor pressure vessel was up to eight atmospheres of pressure—about two times its rated strength.

00:28:23 Things were getting desperate. The second crew was just getting ready to make a run for the valve, determined to open it no matter what the cost, when they got a call from the ERC: white smoke was coming out of the top of the Unit 1 and 2 shared vent stack.

00:28:43 Slowly, pressures in the reactor pressure vessels started to drop. They must be venting. There was no way they could know for sure without instrumentation, but the attempt to open the valve pneumatically must have worked.

00:29:07 They felt a tremendous sense of relief, but that relief would last for about an hour.

00:29:30 This is what an off-site monitoring camera saw at 3:36 PM on Saturday, March 12th. Workers scrambled upon protective gear to figure out what had happened. Their initial fear was that venting the reactor was too little, too late, and that the reactor pressure vessel had just exploded. But thankfully, that wasn't what had happened.

00:30:01 This is what a fuel bundle looks like for a boiling water reactor. A given reactor would have several of these bundles arranged in its core for optimal reactivity. Most of the tubes you see here are the actual fuel rods made of zirconium alloy and filled with uranium fuel pellets.

00:30:19 Now, zirconium is the metal of choice for this because it's very corrosion and heat resistant while also being essentially transparent to the neutrons that sustain the nuclear chain reaction. As the core gets hot enough to melt, though, its corrosion resistance runs out and it starts rapidly oxidizing.

00:30:37 In a reactor pressure vessel filled with steam, the sudden oxidation reaction rips the surrounding water molecules apart, forming zirconium oxide and hydrogen gas, which is very flammable. As the smoke and debris settled, this is what they saw.

00:30:59 Given the shaking of the earthquake and the significant over-pressurization of the reactor's primary containment, it's likely there were plenty of places the hydrogen created by the meltdown could have slipped through. It accumulated at the top of Unit 1's containment building, and all it took was one spark.

00:31:41 The explosion blew radioactive debris across the site. It also caved in a door and an air conditioning intake at the Emergency Response Center, contaminating the one relatively radiation-free space remaining on the site. The work of keeping Units 2 and 3 from melting down got that much harder.

00:32:13 Meanwhile, the situation at Unit 3 was getting pretty critical. The RIC had been passively cooling the reactor since the power loss, but heat was starting to build as they were running out of fresh water on site. Yoshida made the call to use fire trucks to begin injecting seawater.

00:32:36 They had been trying to avoid this because they were still hoping to restart their reactors someday, and the salt in the seawater would ruin the reactor, meaning it could never generate power again. But they had to keep it from exploding—that was the priority.

00:32:58 Back in Tokyo, Prime Minister Kan heard that they were considering seawater injection and demanded that they not do it. One of his small group of technical advisors had mentioned a non-zero chance that the salt in the seawater might cause the reactor to start reacting again to become critical.

00:33:19 In reality, the chance was minuscule and an exponentially smaller risk than a reactor explosion. Masao Yoshida had no intent of complying. Before a video conference with TEPCO execs in Tokyo, he told his staff, 'If they order me to halt seawater injection, I will relay the order to you so they can hear me. You are not to respond and you are not to stop seawater injection. It's our only chance.'

00:33:39 Unbeknownst to them, core damage at Unit 3 had already occurred, and if they had stopped the seawater injection, it might well have exploded. The next day, Unit 3 would experience a hydrogen explosion just like Unit 1.

00:34:01 Unit 4, which wasn't even running at the time of the earthquake, would go on to explode as well from hydrogen gas suspected to have leaked in from Unit 3 via their shared vent stack. They later learned that Unit 2 had experienced core damage as well, and it likely avoided a hydrogen explosion only because its reactor building was damaged enough from the other two explosions to vent the hydrogen instead of letting it accumulate.

00:34:32 You can see Units 1 through 4 in this photo. Three of the four exploded; three of the four are in a state of partial meltdown. At this point, radiation levels at the site were making it hazardous to walk from building to building, with staff running everywhere they needed to go wearing heavy protective gear.

00:35:06 So late in the evening of the 14th, Yoshida made the difficult decision to evacuate most of the staff to Fukushima Daini, Daiichi's sibling plant a few miles away, and only keep a volunteer skeleton crew on site.

00:35:41 Yoshida didn't allow anyone under 45 years old to stay because people under 45 might still have children, and radiation poses more danger to them. Those over 45 were free to leave as well if they wanted.

00:36:02 Nobody was forced to stay. Everyone who chose to stay knew there was a significant chance they'd suffer dangerous radiation exposure, possibly even die. But they felt the responsibility of the rest of Japan to ensure that the plant didn't cause wider contamination.

00:36:25 In the end, there were 68 plus Yoshida left at the plant. This group would be referred to by the media as the Fukushima 50.

00:36:39 Back in Tokyo, Prime Minister Kan heard that conditions at the plant were deteriorating, and shockingly, the TEPCO planned to abandon the plant. 'They can't do that! It would surely explode!' Furious at the news, Kan called a middle-of-the-night meeting.

00:36:58 The TEPCO liaison at Kan's office quickly clarified the misunderstanding—that there was no intention of abandoning the plant, just evacuating non-essential personnel. But it didn't matter; Kan was finished.

00:37:22 'At this point, he uses his authority to create a joint response office, with himself as the lead, taking over control of the response at Fukushima from TEPCO.'

00:37:46 Despite knowing there was never any intention to abandon the plant, Kan carries on like there was. In the internal video conference announcing the change, Kan says, 'If things go on like this, Japan is done for. Abandoning the plant is unthinkable. You must risk your lives on it if necessary. If you abandon the plant, TEPCO will be destroyed.'

00:38:06 These were his words to a room full of people who had just decided to sacrifice their lives if necessary to save this plant. At this point, Masao Yoshida had had enough.

00:38:30 At the front of the room, video conference cameras still running, Yoshida stands up, turns his back on the Prime Minister, and lowers his pants. He makes it look like he's just tucking his shirt back in, but everyone in the room knows what he's really doing. In Japan's formal business culture, turning your back on a superior is a huge etiquette faux pas.

00:39:02 But Yoshida took it exponentially further than that. Now, as the plant slowly came further and further under control, and danger became less, evacuated workers came trickling back in to help. It would take the better part of the year, but finally on December 16th, TEPCO declared cold shutdown at Fukushima.

00:39:43 All reactors were below 100 degrees Celsius and all radiation leaks had been substantially contained. This photo from earlier this year shows the condition of the plant today.

00:40:00 A tank farm sprang up around the plant to contain all the contaminated water. Unit 1 and 2's buildings were able to be repaired, but new containment structures had to be built around Units 3 and 4. Decommissioning work has begun and will likely take the next 30 to 40 years to complete.

00:40:36 In the history of new commercial nuclear power generation, there have only been five reactor meltdowns; three of these were at Fukushima.

00:41:01 To fully understand the severity of the accident, let's put it into context by comparing the amount of radiation it released into the environment. The first commercial reactor to partially melt down was at Three Mile Island in Susquehanna, Pennsylvania.

00:41:20 Three Mile Island's containment hydrogen explosion and subsequent venting released approximately 626 gigabecquerels of radiation into the atmosphere. Fukushima Daiichi, with its three partial meltdowns and three uncontained hydrogen explosions, is estimated to have released 780 petabecquerels of harmful radiation.

00:41:41 Three Mile Island is represented as a one pixel dot here. I promise it's there, but the correct size on this slide would actually be a circle 6.10 millionths of a pixel across. That's how much larger Fukushima was compared to Three Mile Island.

00:42:08 But compared to the largest nuclear accident of all time, Fukushima looks pretty small. Chernobyl, a Soviet RBMK reactor designed famously with no containment of any kind, had exploded and there was nothing to keep it from going straight up into the atmosphere to the tune of 5.2 exabecquerels—around seven times as much radiation as Fukushima.

00:42:36 It was a huge accident, but let's say that the operators at Fukushima had failed to establish cooling and relieve the growing pressure in their containment vessels, and all three running units at Fukushima experience steam explosions. An uncontained failure at all three Fukushima Daiichi units would have released at least 7.5 exabecquerels.

00:43:04 But because Fukushima's reactors had pressure vessels, it’s likely that would have amplified the explosions compared to what happened at Chernobyl. It's almost impossible to guess how bad the accident at Fukushima could have been if not for the heroic actions of Masao Yoshida, Iko Azawa, and all of the other brave operators who risked their personal safety at Fukushima to mitigate the accident.

00:43:24 The only way to have prevented this disaster would have been to move the backup generators to higher ground—something that TEPCO was studying but hadn't yet committed to do at the time of the accident.

00:43:48 It’s almost impossible to improve upon the actions the operators took in the minutes, hours, and days after the accident, so there's nothing the operators could have done differently to get a better outcome.

00:44:05 What should we learn from the accident at Fukushima? Let's talk about Naoto Kan.

00:44:25 Kan resigned on September 2, 2011, in no small part because of the situation at Fukushima Daiichi—not just that it happened, but his handling of it. His distracting visit the morning after the earthquake, his attempted delay of seawater injection, his demoralizing pep talk insulting the very people Japan was depending on to keep the crisis from escalating.

00:44:44 In each case, there was one man that countered Kan: Masao Yoshida. He countered by shielding operators from Kan's interference and rallying them past it; when it was unavoidable, he deftly handled Kan's site visit. He ignored Kan's order to pause seawater injection, and he very tangibly showed the Fukushima 50 that he would not stand for Kan's disrespect.

00:45:27 And he did all of this in a culture where seniority and hierarchy are sacrosanct. A really interesting paper published by Dr. Ruth Ann Heising has some insight for us.

00:45:49 Dr. Heising interviewed several employees who were participating in business process redesign teams at large companies. These teams were working to make fundamental changes about how their organizations worked. Part of the process each of these teams went through was process mapping.

00:46:09 Documenting the steps, conversations, tools, and other activities required to complete a core business activity, like processing an insurance claim or launching a new product, these maps were always surprising for the teams that created them, and they often raised existential questions about employees' roles in the organization.

00:46:33 The reason was that they revealed the actual structure of the organization—the relationships, the information pathways that were responsible for the organization actually being able to get work done. They learned that the actual structure of the organization was an organic, emergent phenomenon, constantly shifting and changing based on the work to be done.

00:46:51 This often bore little resemblance to the formal hierarchy of the organization. Observing the organization is continuously in the making, gave employees an overwhelming sense of possibility, sparking ambition.

00:47:11 Their experience with the mapping exercise shook them out of their well-known helplessness towards the bureaucracy and the way that their companies worked. We've all trained ourselves over the course of our careers to think that the folks at the top of the org chart know more than we do, and they often do have a helpful holistic perspective about the company and the industry in which it operates.

00:47:35 But all the actual work of an organization, all of its output, happens at the bottom of the org chart and the teams at the edge of the organization. Leaders at the top may have a wide perspective, but the edges are where an organization's detailed knowledge lives.

00:47:58 And because of that, the edges are where the majority of an organization's decisions ought to be made. This is where the organic emergent structure that lets an organization actually get work done takes shape.

00:48:16 Which brings us back to Yoshida-san. Ryushu Kadoda, the author of one of the books I read researching this presentation, asks several Fukushima workers how the accident would have been different without Yoshida, and most of them answered with some variant of, 'We'd have been lost without him.'

00:48:36 Several said something like, 'With Yoshida in the lead, we were prepared to die together if we had to.' When asked why, it came down to trust.

00:48:53 Yoshida made it clear over his years of leading Fukushima Daiichi that he trusted his operators and their decisions. They were able to make decisions and work in such harmony during the accident because of the trust he placed in them.

00:49:14 Yoshida continually re-earned and reinforced their trust by doing things like standing up to the Prime Minister.

00:49:30 So what's the takeaway? Well, it depends on who you work for.

00:49:46 If your management resembles Naoto Kan, you're going to have to lean into what the participants in Dr. Heising's business process mapping exercise learned. I'm now focused on inventing the board and not just playing the game.

00:50:06 Trying to see what's really out there and not arguing too much for the limitations that maybe aren't so real. You can see this in the way that Yoshida responds to Kan.

00:50:31 The rules of the game, especially in Japan, are extreme deference to hierarchy and superiors. But the possibility Yoshida was fighting for was not blowing up the plant.

00:50:47 It's not all rebellion all the time, but it might mean knocking your deference for your leaders down a notch or two and trusting yourself a little bit more so that you can get work done.

00:51:11 But if your management is more like Masao Yoshida, your job is to lean into the trust that they give you—to try things, to use the safety that they create, and the guidance they offer to learn, to grow, and to push the business forward.

00:51:32 You likely still have some learned helplessness built up from your career, and even with high-trust leadership, you're still going to have to learn how to create the game rather than play it.

00:51:51 And if you're a leader, I hope the lesson here is obvious. I can chart my career by the talks that I've given, because they're always around what I'm learning in the moment that I write them.

00:52:09 My focus right now in leading the engineering team at Sim is to see what happens when a company's whole leadership team leans into the idea that everything important happens at the edge of the company.

00:52:34 And the rest of us are there to support that— to really trust, empower, support, and guide, not dictate and lead by road.

00:52:54 Our engineering team has grown more and taken on more leadership responsibility than I would have ever thought possible, and we're moving remarkably fast because of it. Because of that autonomy, it's been one of the biggest privileges of my career to be there for it.

00:53:16 I hope everyone in this room gets a chance to experience or maybe even create a team like that at some point in your career. Good things like this—they're worth fighting for. Thank you.