CNO Summit Diary: Peter Sena of First Energy Reflects on Lessons of Fukushima After Attending US-Japan CNO Summit

While the U.S.-Japan CNO Summit has ended and the American delegation has returned home, we're still seeing reports come in from their time in Japan. The latest is this video diary from Peter Sena, President and Chief Nuclear Officer of First Energy. In this video vignette, Sena reflect on the lessons he learned after visiting Fukushima Daiichi and meeting face to face with TEPCO employees who are working to clean up the site:



As always, please keep up to date with the latest content by following #CNOSummit on Twitter.

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CNO Summit Diary: Why FLEX Is The Right Response to Fukushima

Maria Korsnick

Constellation Energy Chief Nuclear Officer Maria Korsnick was in Japan last week touring the country’s nuclear facilities with a prominent group of U.S. chief nuclear officers. 

This is the second in a series of travel logs that Maria recorded. You can read an earlier diary entry from Maria, here. Additional coverage of the CNO Summit is on Twitter at #CNOSummit.

Earlier this week I toured Fukushima Daiichi and Fukushima Daini. The stations are only 7.5 miles apart but the contrast is remarkable. When approaching Daiichi, we were stopped at a village 12 miles from the station. The area was previously used as a training facility for Japan's soccer team, but today it serves as temporary housing for site workers and a plant access checkpoint. Each of us received a whole body count before boarding a bus to Daiichi.

The view from the bus window will stay with me forever. It looked like a war zone. The earthquake and the force of the tsunami were evident everywhere. The town was empty, the houses are decaying and the storefronts are damaged. You are surrounded by broken glass, twisted metal and overturned vehicles. Large storage tanks have been torn from their mounting plates and pushed aside. Pieces of the reactor building serve as constant reminders of the hydrogen explosion.

When we arrived at the site we were issued paper face masks, anti-contamination clothing and shoe covers. We dressed out and boarded another bus to tour the station grounds. The seats are covered in pink plastic herculite sheets to further protect us from contamination. As we drove the site, I could see that many buildings were still uninhabitable. Others had been converted to shift worker resting areas or additional checkpoints.

There are six reactors on this site. Units 1, 2 and 3 have damaged cores. Units 4, 5 and 6 do not, but they will never operate again. Decommissioning the entire site will take 30+ years. The biggest challenge right now is water: too much of it in the wrong place to be exact. Rows and rows of large tanks, similar to our condensate storage tanks, are being used to hold contaminated groundwater. The earthquake collapsed the underground drainage system, so the groundwater is collecting around the buildings and leaking in. The reactor building is contaminated from the accident, so the water becomes contaminated, too. They pump the water into the tanks to clean it, but keeping up with the volume of water is very challenging and they can't discharge anything. Even water clean enough to meet U.S. EPA standards cannot be discharged.

Currently they are clearing more land and installing more tanks, but a better solution is needed. Making matters worse, many of the original tanks were bolted together, not welded, and prone to leakage. Cleaning up water and fixing leaks continues 24/7 while they seek a viable long-term solution. It's a massive challenge but it’s evident that they are working very hard to get their arms around it.

The following day we toured Fukushima Daini and its four reactors. The station is only 7.5 miles from Daiichi, so it experienced the same earthquake and tsunami. They also lost power and their emergency diesels and electrical cabinets were affected by flooding. Damage is evident in a few places but, for the most part, the station has been cleaned up and repaired. They fought the same storm, but with the benefit of a few design and response differences, they won.

Unlike Daiichi, Daini retained power to some of the instrumentation in the control room, so they could assess the status of key systems. They were able to rally their site team and find creative solutions. They ran over six miles of heavy electrical cable, in about a day, to bring in offsite power to support their safety systems. Over 500 employees stayed for weeks to support the site. It's an amazing story of an engaged team, under extreme stress, with strong leadership that brought amazing results.

It's clear that the negative outcome of Daiichi overshadowed Daini's remarkable performance. As nuclear professionals, we can learn as much from what went right as we can from what didn't. They proved that our portable, diverse equipment strategy know as FLEX can be successful in protecting their plant and their people. Back home, we need to continue to prepare for and defend against beyond design events. With pre-staged, portable equipment, we can give our team options. The equipment is in place now, but additional training and procedural guidance over the next several months will make us even better prepared for the unimaginable.

Standing here at Fukushima Daini, I'm confident that our FLEX strategy is the right approach for our stations and the industry as a whole. I'm comforted to know that it worked here, and very thankful to our Japanese colleagues for their dedication, hard work and many successes.

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CNO Summit Diary: PG&E's Ed Halpin on the Lessons From Fukushima

Ed Halpin, SVP & CNO of PG&E

Ed Halpin, Senior Vice President and Chief Nuclear Officer at PG&E, was in Japan this week with virtually all of his American colleagues as part of the U.S.-Japan CNO Summit. He shared this diary entry with us after reflecting on what he saw at Fukushima Daiichi earlier this week. Be sure to follow all the updates from Japan on Twitter using the #CNOSummit hash tag.

As nuclear operators, we have earned a special trust from the communities we serve. My time here reaffirms my belief that the U.S. nuclear industry must always maintain its strong focus on safe operations, intensive training programs, effective peer-review processes, and the continued sharing of lessons-learned across the nation and throughout the world. The U.S. industry has always relied on redundant layers of safety in operating its facilities and is making exceptional gains in implementing a program known as "FLEX" to further enhance safety in the face of extreme natural events.

"FLEX" addresses the major challenges encountered at the Fukushima Daiichi power station following the March 11, 2011, earthquake and tsunami: the loss of power to maintain effective reactor fuel cooling. The strategy focuses on providing an uninterrupted supply of electricity and cooling water to protect critical plant safety systems at all times and ensuring that every U.S. nuclear energy facility can respond safely to extreme events, no matter what the cause.

My belief is that mandating more modifications or changing our design requirements based on the worst potential natural disasters and assuming conditions that are highly improbable will only complicate our response to such an event. Certainly we need to close out the more important issues that are currently on the table and in keeping with our industry "Path to Excellence." Even more importantly, we need to continue to emphasize a strong operational focus with rigorous, realistic training. We must be able to implement our FLEX strategies blindfolded across every operating crew and our emergency response teams and training have got to be exemplary. These actions honor the trust we have earned from our communities and customers and keep us focused on our primary goal - safety.

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CNO Summit Diary: Indelibile Impressions From a Historic Week

Editor's Note: For the past week, NEI's John Keeley has been accompanying a delegation of American chief nuclear officers on a tour of Japan. This is his last blog entry he'll make before returning home to the U.S. 

To find all of the content related to this week's trip from NEI Nuclear Notes, click here. And for all of the chatter about the trip on Twitter, check out the #CNOSummit hash tag. Thanks to John for a job well done. 

(Tokyo, September 13) I won't miss jet-lag-induced risings at 3 a.m.each and every day -- and apparently I was joined in those by each and every American chief nuclear officer and communicator -- but just about everything else on this trip created a once-in-a-lifetime experience for me. So I thought I'd share those moments that stood out most to me: 

• At every formal engagement between U.S. and Japanese nuclear officers this week our hosts started the proceedings with a formal apology "for the concern and difficulty and confusion we have caused."  

• Takeyuki Inagaki had the closest and worst seat to the history made at Fukushima Daiichi, stationed in the unit 1 control room and later in the site's Emergency Response Center during the first 100 hours of the accident. The reflections he offered our CNOs about his experience were subdued, poignant, and commendably frank. If you asked him I'm sure he'd tell you he regards his English as poor, but he held our room in rapt attention -- and empathy -- while he spoke. I also thought he was surprisingly composed. My eyes teared up each and every time he uttered this haunting refrain, which he said accompanied each and every instance he had to order one of the Fukushima 50 back into harm's way for inspections: 'Am I [going to be] a murderer?'   

• We toured the Daini and Daiichi sites in the Fukushima prefecture because, while they endured virtually identical trauma circumstances on March 11, 2011, the outcomes between the sites were dramatically different, and the way the sites responded to the conditions offered a stark contrast as well -- particularly from the vantage of leadership.  

• Daini had recovery tools at its disposal that Daiichi did not, but there was a spirit of innovation, too, that guided Daini personnel. It's fair and accurate to say that U.S. CNOs very much applied learnings from the Daini experience into their formulation for the U.S. FLEX strategy. 

• Pete Sena, CNO for FirstEnergy, to the Wall Street Journal on Thursday: "Daini's story hasn't been told. The workers at Daini are national heroes." In the Journal he was quoted thusly: “The takeaway for me personally is internalizing what I saw with my own eyes to make sure this never, ever, ever happens within the U.S.,” he said. “That’s the message I want to get across to my entire workforce, and to the folks on the outside: What we do — it’s not a business; it’s personal.”  

• Naohiro Masuda, Vice Head, TEPCO Nuclear Safety Oversight Office, and Daini station leader on 3/11, very early in his briefing remarks to the U.S. CNOs: "As children, we were always told to hide under our desks at the arrival of an earthquake, but we never did. On 3/11, for the first time in my life, I did."  

• Some 500 employees remained at the Daini station for upwards of a month, returning not once to their homes -- if they even had homes to return to -- and working as a trauma team in circumstances our industry had never even considered, let alone encountered. Many slept on floors, subsisted on rudimentary nutrition, and went weeks without changing clothing.  

• Busing through the ghost towns of Fukushima, wherein storefronts bore the identical staples they did on March 11, 2011. 

• Chief Nuclear Officers in the United States are First Safety Officers at their sites. It's a designation they hold sacred.     

• They are also a special fraternity. They are, in Randy Edington's words, "Hostages of each other." One need only be in their company a few hours to notice the special bond they've forged. They are collegial and clique-free, and quietly and discretely they adhere to a rigid honor code: one which promulgates a culture demanding that they lead in a manner that ever serves the best interests of the nuclear industry, even, if need be, at the expense of their own utility. That code is neither theory nor supposition.   

• Working in the nuclear industry is a source of immense pride for me. I'm returning home bearing a good deal more.

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CNO Summit Diary: Dressing Out to be Witnesses to History

At one point Wednesday, while within a few hundred yards of the three melted down reactors at Fukushima Daiichi, I was outfitted in three layers of gloves (two rubber, one cotton), plastic covers over my shoes, a very hot and very insulating Tyvek jumpsuit, and a respirator mask. The interior of our tour bus was fantastically shielded in plastic, and when, while maneuvering on a road between the ocean that sent the monstrous March 2011 tsunami and Daiichi's turbine buildings, our driver dramatically increased our speed as we arrived in front of unit 3, where the dose rate was highest on the site, to limit our exposure.

Storefront in an abandoned village.

All week the chief nuclear officers on this trip have regularly referenced their collective need to experience, first-hand, conditions in Japan that all but only a few have only read about. Our bus' movements, and our in-person engagements with shift managers and control room operators on duty the afternoon of March 11, 2011, at both Daini and Daiichi have ensured that they have.  

One of the many things I've learned this week is how marvelously our industry manages radiological protection. Each day our tour groups were on the Daiichi site (Tuesday and Wednesday) for upwards of 5 hours; our total dose each day, with negligible variation, was 2 millirem -- nothing compared to the 300 millirem we Americans naturally receive in background radiation each and every year.

Randy Edington, CNO at Palo Verde, has made a point of distinguishing the conditions he encountered on a visit he made to Daiichi in December 2012 with those our group is witnessing this week. Last December, Edington told me, his tour bus couldn't even approach the access road in back of unit 4, as we did Wednesday. There was late last year an enormous debris field still blocking access, and the dose was too high.

This week Edington has observed the removal of a dramatic volume of debris from numerous areas around the site, most particularly a massive mass of twisted steel that ominously cluttered the top of units 3 and 4. Additionally, there's a new building constructed next to and over unit 4 so that used fuel can be offloaded, perhaps later this year. Significant progress is being made here, without question, but of course one can't ignore some small practical matters whose disposition serves as an exclamation point for the consequences of what happened here 30 months ago: Every plastic bottle of water consumed by site workers and visitors necessarily will never leave the site -- it's radiological waste.

"Three-eleven is not over," one CNO told our assembly Thursday morning, while meeting in downtown Tokyo. "And it won't be for a long time." Another lesson necessarily learned from our visit. 

* * * * *

We were on Tuesday and Wednesday witnesses to history. There are memorial markers about Daiichi's turbine buildings chronicling the levels the tsunami water rose within. One set of floodlights in one turbine building corner still had tsunami water within its glass facings.

A field used to store contaminated soil.

A tsunami is a marvel of malevolent nature, a wall of water wider than our eyes' periphery, moving at times faster than 500 miles per hour. At Daiichi it took industrial strength steel -- and concrete -- and twisted it like Twizzler sticks. We saw just offshore a fantastically reconstituted and fortified seawall-breaker, but within the repaired line of defense a sobering reminder of the force that struck: pickup truck-sized chunks of concrete churned into a wide debris field. Daiichi's seawall was shredded by this monster.

"Nature, sometimes without mercy, comes and attacks us," one Daiichi reactor operator told our CNO's at a briefing Wednesday afternoon.           

* * * * *

The American CNOs have been changed this week by their engagements with site supervisers, shift managers and operators who were on duty that fateful 2011 afternoon. It's freshly searing to hear first-hand accounts from TEPCO personnel of how little they knew -- sometimes for weeks -- of the fate of their families, as first a 9.0 magnitude earthquake and then a historic 15-meter wall of water ravaged their land. The CNOs are having robust discussions trying to figure out protocols by which American nuclear utilities can communicate family status to site personnel who are on duty during notably destructive, but not adequately forecast, events. Industry already has such a protocol for hurricane conditions, for instance, but almost always sophisticated meteorological capabilities assure us of enough advance warning with which to account for family. As a consequence of what happened in Japan, and hearing of its impact first-hand, our CNOs want even more protective measures in place for our site personnel.        

And if the horror of March 2011 wasn't enough for Daini and Daiichi families, some relayed this to the American CNOs this week: in some communities, the children and spouses of some Fukushima personnel are regularly harassed and bullied by their embittered neighbors. 

* * * * *

At both Daini and Daiichi officers, operators and managers desperately wanted to know what more in safety strategy they ought to consider, and they looked to the Americans to tell them. In an especially poignant moment, Randy Edington stood up in a crowded conference room, held up his smart phone, pointed to the entirety of his traveling CNO contingency, and said, "In a crisis, I have each and every one of them on speed-dial." There aren't merely two Emergency Response Centers now in the United States, Edington added. There have long been 63 -- the location of every commercial nuclear power plant -- and at every one a CNO poised to aid when most needed to.    
   

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CNO Summit Diary: Entergy Nuclear CNO Calls Visiting Fukushima Daiichi 'Life-Altering'

The past two days in Japan, U.S. chief nuclear officers have toured Fukushima Daini and Daiichi, and with respect to the latter, left the experience appreciably changed. We've made a point each day of inviting the CNOs to the very back of our tour bus and asking them to share their experiences on camera with us.

It's true that every CNO we spoke with identified the Daiichi visit as life-altering, but no reaction seemed better representative of the CNOs than that of Jeff Forbes, Executive Vice President and Chief Nuclear Officer for Entergy Nuclear. Just watch.

Please remember to follow our updates on Twitter using the #CNOSummit hash tag.

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CNO Summit Diary: Maria Korsnick's Reflections from Japan

Maria Korsnick

Maria Korsnick is Chief Nuclear Offiicer (CNO) of Constellation Energy. In the aftermath of Fukushima, Maria appeared in a series of videos for NEI explaining exactly what changes the industry was effecting in the wake of Fukushima. 

She's in Japan this week as part of a delegation of American CNOs touring the country’s nuclear facilities as part of the U.S.-Japan CNO Summit. This is the first in a series of travel logs that Maria recorded to share her experiences. Please remember to follow our updates on Twitter using the #CNOSummit hash tag.

As I boarded the plane for Japan, I wondered what it was going to be like to experience our business in a completely different culture. Once I arrived, it didn’t take long to generate some first impressions. My hosts were welcoming and polite, surroundings were neat and orderly and properties were well-cared for. It’s abundantly clear that the Japanese people take pride in their surroundings.

Japan has only one-third the population of the United States; however the entire country is roughly the size of California and only 27% of their land is habitable. That means lots of people in a small space. For perspective, greater Tokyo is home to a staggering 30 million people. Despite its population density, Japan doesn't exude the chaos of a crowd. Trains arrive and depart precisely on schedule, the cars are clean and you better be in line to board or it will leave without you. Thousands of people move around quietly and in orderly fashion. There’s no trace of graffiti, trash or cigarette butts anywhere.  It’s quite unlike anything you would see in any large American city.

Tokyo at night.

On our first day, we took a train and a bus to a plant known as “KK”, three hours outside Tokyo. There are seven reactors on the site but none are currently operating. They are in the process of updating their tsunami counter measures. We were warmly welcomed by our hosts. American and Japanese flags were displayed side by side. We had a good discussion on their learnings from the 2007 NCO earthquake. They have since built upon their already strong design and made enhancements to add margin.

The plant tour was quite impressive. Inside the Unit 7 control room (it’s an advanced BWR design) operators use digital controls and operate plant equipment from computer screens. A member of the Japanese regulatory body was present in the control room, much like NRC residents tour our plants and ask us follow up questions. A banner in the room read, “World Class Nuclear Plant: Resilient to Natural Disasters.” I wish them well on their journey to re-start the units. 

At the end of day one, I remember thinking that the world of nuclear translates well. Regardless of what language was being spoken, attentive operators worked in pristine conditions and focused intently on effective communications and procedure adherence to ensure safety. Sounds like us!

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CNO Summit Diary: Chasing lessons in safety at Fukushima by chasing the sun

The following post was sent to us via email by John Keeley, who is travelling with a delegation of American chief nuclear officers in Japan this week. You can follow John's observations on Twitter by following @nei_media and the #CNOSummit hash tag.

In summer, in morning or early afternoon, when a traveler moves by air many thousands of miles from east to west, he never quite escapes the bright sun of day. My communicator colleagues here in Japan all noted the difficulty we had securing substantive rest on our flights over the Pacific during this novel journey. We were ever chasing the sun, they said.

The American chief nuclear officers we're following with our cameras and electronica this week have been, ever since their arrival here, in perpetual motion in pursuit of safety lessons. In making the unprecedented and extraordinary commitment to "put eyes on the problem" created by the 3/11 Fukushima tragedy, our CNOs, it occurs to me, are following a global commitment to safety much as we communicators were following the sun.

Remember: this is a trip undertaken *after* U.S. CNOs had unanimously adopted significant safety enhancements at all 63 operating stations in response to the Fukushima accident.

The CNOs I ran into late on Sunday night were every bit as bleary-eyed and time-zone tortured as we communicators, but about 15 of them awoke at the crack of dawn Monday morning in order to board buses and trains to Kashiwazaki Kariwa, the largest nuclear generating station in the world with a capacity of 8200 MWs and 5400 employees.  Since 2007 the station has invested almost $2 billion dollars fixing earthquake damage and installing post-Fukushima modifications. There were significant safety lessons to be learned in seismic and flooding space at Kashiwazaki, and so our CNOs bused hours across this island to learn them.

They returned from that site about an hour before meeting their Japanese CNO counterparts at Monday night's welcoming reception. There's no rest for the safety-lesson-craving weary on this trip, and well before a new workday had started in Tokyo on Tuesday every American CNO was back on a tour bus, this time headed for site visits at both Fukushima Daini and Daiichi. We'll have a lot more to say and illustrate about those two extraordinary site visits in the days ahead, but at the end of a hot Tuesday of touring the CNOs were still very much in motion, still very much  in learning mode.

Darkness was fast setting upon our tour, but instead of heading to our new hotel and a badly needed hot meal our buses trudged slowly through a town called Tomioka. It's a seaside town quite near both Fukushima plant sites, and on March 11, 2011, it knew 16,000 residents. It was a community known in summer for festivals and parades.

Tomioka. Photo used under Create Commons License through Wikipedia

Today it's devoid of human existence, devastated by the tsunami and uninhabitable by radiological fallout. Unchecked nature is overgrowing much of what had been developed and thriving little more than two years ago.

Fallout from the Daiichi accident delivers 1-3 millisieverts microsieverts an hour in Tomioka. The Japanese government has begun decontamination efforts for the town, and there is a plan to have is habitable by 2017, but today it is a sobering wreck of abandonment. Our CNOs wanted to see with their very own eyes the ultimate consequences of a day gone very wrong at a plant.

I wish them all some early and deep shuteye tonight. They're off to freshly pursue safety lessons through the total  sun again of tomorrow.

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CNO Summit Diary: Randy Edington of Arizona Public Service Reports from the US-Japan CNO Summit

Following on John Keeley's message from earlier this morning, here's the first video message we've received out of Japan regarding the #CNOSummit that's taking place there this week. It's from Randy Edington, Executive Vice President and Chief Nuclear Officer of Arizona Public Service. Though the video is intended for Randy's team back in Arizona, we think the message about the trip is universal:



Look for more content from the #CNOSummit all week both here at NEI Nuclear Notes and on Twitter.

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CNO Summit Diary: Dateline, Japan: Following history in the advance of safe nuclear operations

Often, I travel most modestly on behalf of the U.S. nuclear industry -- like say up and back to the Nuclear Regulatory Commission for public meetings, some 7 miles from NEI's offices in Northwest Washington. But about a month ago, as word began circulating in the office about a sizable contingent (almost all) of our nation's chief nuclear officers traveling to Japan to meet with their Japanese CNO counterparts, NEI communications leadership saw a clear role to try and capture the historic visit in words and images. And tweets, of course.

My bosses picked me to tag along with the CNOs (almost 30 of them), as a bit of an embedded reporter. I've a daunting task in that regard. 

To be sure, this is a historic visit; nothing of its kind has been undertaken before in the history of commercial nuclear operations in the U.S. For the first time, the chief nuclear officers from the U.S. and Japan will meet together to discuss lessons learned from a severe accident: specifically, actions at Japanese plants during the 2011 earthquake and tsunami as well as steps companies in both countries are taking to enhance safety at nearly 150 reactors total.

And of course, we've a remarkable backdrop for this trip: news reports the past few weeks have been voluminous -- and, in must be noted, hyperbolic -- related to accounts of TEPCO's management of contaminated water at the Fukushima site. What is actually true is that one water tank on the site developed a leak, it was subsequently stopped, and the remaining water in the leaking tank was transferred. Additionally, the contaminated areas around the affected tanks have been treated, and radiation and tank water levels are being continuously monitored. There has been no threat to public safety. I'm confident the American traveling contingent will return home in a week's time with a great deal more information about conditions at Fukushima Daiichi and Daini.        

The idea for this spectacular summit really goes to Randy Edington, the chief nuclear officer of Arizona Public Service's Palo Verde nuclear plant. Randy visited Fukushima back in January, and he was so moved by the implications of the accident that he made it his mission to persuade his CNO colleagues to come over to Japan together, to experience what he experienced. It's a powerful statement I think of the U.S. nuclear industry's commitment to safety and continuous learning that we have just about every American CNO on this trip. 

Tokyo at night.

Credit for the enormous logistics necessary to pull off such a visit goes to the Atlanta-based Institute of Nuclear Power Operations. INPO shared Randy's view of the imperative of seeing, firsthand, the consequences of the Fukushima accident, discussing the U.S. response to the event, and interacting with the Japanese CNOs to convey, quite personally, our ongoing commitment to helping. INPO has dispatched an impressive team of talented videographers to chronicle the trip as a legacy and teaching moment. I'll be working closely with them.      

I feel most fortunate to have been selected to travel to Japan with our CNOs, and to aggregate as much content on the ground here as possible, and share it with you. We have plans to publish still and video images, on Facebook and the blog here, and on Twitter (@NEI_media and @N_E_I) I'll share my experience with the hashtag #CNOsummit. But the communications product I'm most excited about is a series of digital diaries I've asked a handful of my companion CNOs to keep for me. A fair number of them are traveling with iPads, and I thought it could be terrifically illuminating to have them construct something akin to digital postcards of their experience, and share them with you. Look for those in the days ahead.

A part of me is intimidated by a communications challenge obviously unlike anything I've ever attempted before, one which seems massive in scope and technical care and delicacy. But I'm keeping the best possible company, working alongside men and women of marvelous commitment and ability. I'm looking forward to bringing you their story.      

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Japanese Government: No Plans to Re-Start Fukushima Daini

Earlier this week, a Japanese government official said that there were no plans to restart any of the reactors at the Fukushima Daini nuclear power plant.

Fukushima Daini was a textbook example of how things can go right at a nuclear power plant in the face of an extreme event, something we noted at our SafetyFirst microsite in December:

When the earthquake struck, the Fukushima Daini facility automatically shut down safely as designed. However, it went into a state of emergency following the tsunami when water damage disrupted heat removal systems in three of the four reactors.

TEPCO reactor operators were able to quickly bring reactor 3, which had retained its heat removal function, into stable condition in a matter of hours. Meanwhile, other employees worked feverishly around-the-clock to reestablish heat removal capability in the other three reactors and finished stabilizing them by March 15.

A key distinction between the post-disaster conditions at Fukushima Daini and Fukushima Daiichi was that off-site power was available at the Daini facility, whereas the Daiichi plant suffered a complete loss of electricity, including backup generators and, eventually, emergency batteries needed to power reactor cooling systems. Fukushima Daini workers were able to tap into electricity from a 500-kilovolt-transmission line – a key lifeline – to power a water injection system that helped cool the reactors as they shut down.

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