0:00:07 > 0:00:11Last year, seven days after the tsunami that devastated Japan,
0:00:11 > 0:00:17firefighters headed into the critically damaged Fukushima nuclear complex.
0:00:20 > 0:00:22Three reactors were in meltdown.
0:00:24 > 0:00:27The mission was to navigate through radioactive debris
0:00:27 > 0:00:30and spray water onto lethal nuclear fuel.
0:00:32 > 0:00:36If they failed, the government feared that radiation would
0:00:36 > 0:00:39leave a vast area of Japan uninhabitable.
0:00:53 > 0:00:57This film uses unique video from the front line of the disaster
0:00:57 > 0:01:02and footage we filmed later with the men who fought to save the reactors.
0:01:02 > 0:01:06It's the inside story of the Fukushima meltdowns -
0:01:06 > 0:01:10told by those who were there.
0:01:19 > 0:01:23It's the story of lives upended by the radioactive fallout.
0:01:29 > 0:01:34And the story of a prime minister who gambled with lives
0:01:34 > 0:01:37to avert even greater catastrophe.
0:02:52 > 0:02:56The earthquake that shook the Fukushima Dai-ichi nuclear power plant
0:02:56 > 0:03:00was the most powerful to strike Japan since records began.
0:03:02 > 0:03:05The corporation that operates the plant, TEPCO,
0:03:05 > 0:03:09has forbidden its workers from speaking publicly.
0:03:10 > 0:03:13But, one year on, some are telling their stories.
0:03:47 > 0:03:50Japanese power plants are designed to withstand earthquakes,
0:03:50 > 0:03:54and the reactors automatically shut down within seconds.
0:03:54 > 0:03:59But the high radioactivity of nuclear fuel rods
0:03:59 > 0:04:02means they generate intense heat even after a shutdown.
0:04:04 > 0:04:08So backup generators kicked in to power the cooling systems,
0:04:08 > 0:04:10and stop the fuel rods from melting.
0:04:18 > 0:04:21Takashi Sato, a reactor inspector who no longer
0:04:21 > 0:04:25works at the plant, kept a detailed log of what happened that day.
0:04:51 > 0:04:56Just up the coast, the fishermen of Fukushima knew what was coming next.
0:05:14 > 0:05:17Yoshio Ichida wanted to save his boat.
0:05:17 > 0:05:20He was gunning straight into the biggest tsunami waves
0:05:20 > 0:05:23to strike Japan in hundreds of years,
0:05:23 > 0:05:26hoping to crest them before they broke.
0:05:53 > 0:05:57The highest of the waves was more than twice the size of the sea wall
0:05:57 > 0:06:00guarding the nuclear power plant.
0:06:25 > 0:06:26At the nuclear plant,
0:06:26 > 0:06:31a worker was filming as his colleagues fled to higher ground.
0:06:44 > 0:06:48At 3.35pm, the biggest of the waves struck.
0:06:53 > 0:06:56TEPCO had been warned by scientists
0:06:56 > 0:06:59that its tsunami defences were inadequate,
0:06:59 > 0:07:01but had taken no action.
0:07:01 > 0:07:05The company says it was still reviewing the matter.
0:07:09 > 0:07:13Now the tsunami overwhelmed the sea wall
0:07:13 > 0:07:15and began to swamp the nuclear plant.
0:07:34 > 0:07:39Yukio Murakami - not his real name - is a senior TEPCO nuclear engineer,
0:07:39 > 0:07:42who still works at the plant.
0:07:42 > 0:07:45He's asked for his identity to be hidden
0:07:45 > 0:07:48because of the company's ban on interviews.
0:08:10 > 0:08:17Most of the backup diesel generators - needed to power the cooling systems - were located in basements.
0:08:17 > 0:08:19If they were no longer working,
0:08:19 > 0:08:23the nuclear fuel could eventually melt down into the ground
0:08:23 > 0:08:27and release catastrophic amounts of radiation.
0:08:50 > 0:08:52This is the frantically scribbled log
0:08:52 > 0:08:55the engineers kept in the control room,
0:08:55 > 0:08:58as the nuclear plant slid towards disaster.
0:08:59 > 0:09:02"15.42 - nuclear emergency declared.
0:09:04 > 0:09:08"15.58 - loss of water-level readings.
0:09:09 > 0:09:15"16.36 - emergency core cooling system malfunction.
0:09:15 > 0:09:17"No water is being injected."
0:09:23 > 0:09:29The executives of TEPCO - one of Japan's biggest and most powerful corporations -
0:09:29 > 0:09:33had never imagined that one of their nuclear plants could lose all power.
0:09:35 > 0:09:37They had no plan for what to do next.
0:10:06 > 0:10:10In the 90 minutes since the tsunami,
0:10:10 > 0:10:12Japan's government had been scrambling to deal with
0:10:12 > 0:10:17one of the biggest natural disasters in the country's history.
0:10:17 > 0:10:20Now, the prime minister was informed that the cooling systems
0:10:20 > 0:10:23had failed at Fukushima.
0:10:55 > 0:10:59The government sent out emergency generator trucks to the stricken plant.
0:10:59 > 0:11:02To avoid a meltdown, every minute mattered.
0:11:05 > 0:11:11But the trucks were soon snarled in traffic caused by the earthquake.
0:11:22 > 0:11:25Two hours had now passed since the tsunami.
0:11:27 > 0:11:29The coastline was devastated.
0:11:30 > 0:11:35Around 20,000 people were dead or missing.
0:11:40 > 0:11:43Norio Kimura, a farmer from Fukushima,
0:11:43 > 0:11:46lived just two miles from the nuclear plant.
0:11:48 > 0:11:51He'd been out working when the waves struck.
0:11:51 > 0:11:54Now he was searching for his family.
0:11:55 > 0:11:59Survivors were gathering at the local sports centre,
0:11:59 > 0:12:02unaware of the unfolding nuclear crisis.
0:12:30 > 0:12:33Norio's father was missing.
0:12:33 > 0:12:37So was his wife, and his youngest daughter, Yuna.
0:13:03 > 0:13:05As night fell,
0:13:05 > 0:13:08the Japanese government ordered a precautionary evacuation
0:13:08 > 0:13:11of everyone within two miles of Fukushima Dai-ichi.
0:13:11 > 0:13:15But Norio and others ignored the order
0:13:15 > 0:13:20and kept searching for their families in the shadow of the nuclear plant.
0:13:28 > 0:13:33The first generator trucks arrived at the plant as midnight approached.
0:13:33 > 0:13:38The reactors had now been without power for more than seven hours.
0:13:50 > 0:13:53But the generators needed to plug into a distribution board,
0:13:53 > 0:13:56which was in a basement.
0:14:05 > 0:14:07The relief plan had failed.
0:14:08 > 0:14:12The engineers now faced a full-blown nuclear disaster,
0:14:12 > 0:14:15and had no working instruments to reveal what was
0:14:15 > 0:14:18happening inside the reactor cores.
0:14:19 > 0:14:22They resorted to desperate measures.
0:14:39 > 0:14:43The scavenged batteries allowed vital monitoring instruments
0:14:43 > 0:14:45in the Reactor One control room to work again.
0:14:47 > 0:14:52Just before midnight, the workers restored power to the pressure gauge.
0:14:53 > 0:14:55The readout caused panic.
0:15:08 > 0:15:10The engineers realised the rising heat
0:15:10 > 0:15:13of the fuel rods in the reactor core
0:15:13 > 0:15:17was creating massive amounts of radioactive steam and hydrogen.
0:15:17 > 0:15:19The resulting pressure
0:15:19 > 0:15:22meant the workers could not get water onto the fuel.
0:15:22 > 0:15:27Even worse, it meant the containment vessel might explode,
0:15:27 > 0:15:30a disaster that could leave parts of northern Japan
0:15:30 > 0:15:33uninhabitable for centuries.
0:15:45 > 0:15:49In Tokyo, the prime minister received a chilling message.
0:15:49 > 0:15:56The workers in Fukushima urgently needed to release the radioactive gases into the atmosphere
0:15:56 > 0:15:58before the reactor exploded.
0:16:13 > 0:16:17Radiation has long been a sensitive subject in Japan.
0:16:25 > 0:16:31After America dropped atomic bombs on Hiroshima and Nagasaki in 1945,
0:16:31 > 0:16:35tens of thousands died of radiation sickness and cancers.
0:16:37 > 0:16:41Yet now Japan's prime minister felt he had no choice
0:16:41 > 0:16:45but to authorise the deliberate release of radioactivity.
0:16:58 > 0:17:02But there was something TEPCO wasn't telling the government.
0:17:02 > 0:17:04The company had never envisaged
0:17:04 > 0:17:08they might have to vent a reactor without electricity.
0:17:09 > 0:17:11They didn't know how to do it.
0:17:29 > 0:17:33In the darkness of the Reactor One control room,
0:17:33 > 0:17:35the workers pored over blueprints
0:17:35 > 0:17:38to try to work out how to open the vents.
0:17:41 > 0:17:46The handwritten plant logs show that radiation levels were now rising.
0:18:05 > 0:18:09The engineers suspected something that the government and TEPCO
0:18:09 > 0:18:13would not acknowledge for months - nuclear meltdown had begun.
0:18:33 > 0:18:36Back in Tokyo, six hours after the order to vent the reactors,
0:18:36 > 0:18:40there was still no news from the plant.
0:18:40 > 0:18:43The government was starting to suspect
0:18:43 > 0:18:46that TEPCO was hiding the truth from them.
0:18:48 > 0:18:51The prime minister made a sudden decision.
0:18:51 > 0:18:54He would go to Fukushima Dai-ichi himself.
0:19:24 > 0:19:26At Fukushima Dai-ichi,
0:19:26 > 0:19:30the prime minister met directly with the TEPCO engineers.
0:19:30 > 0:19:33He insisted they vent the reactors.
0:19:58 > 0:20:04The plant manager, Masao Yoshida, was known for his straight-talking.
0:20:04 > 0:20:08He knew the radiation near the vents was at potentially fatal levels
0:20:08 > 0:20:13but he told the prime minister he'd send in a suicide squad if necessary.
0:20:22 > 0:20:24The prime minister returned to Tokyo.
0:20:26 > 0:20:31He knew his orders might condemn the men who went into the reactors to death,
0:20:31 > 0:20:35but he felt Japan's future was at stake.
0:20:54 > 0:20:57But still the venting did not happen.
0:20:59 > 0:21:03News had reached TEPCO that the evacuation of the surrounding villages
0:21:03 > 0:21:05was not yet complete.
0:21:08 > 0:21:11People were still searching for missing family members
0:21:11 > 0:21:14in the devastation of the tsunami.
0:21:14 > 0:21:16If the reactors were vented,
0:21:16 > 0:21:21they could be exposed to dangerous levels of radiation.
0:21:21 > 0:21:24One of them was Norio Kimura.
0:21:40 > 0:21:43Norio had found one of his daughters, Mayu.
0:21:46 > 0:21:50But he was still searching for his youngest daughter,
0:21:50 > 0:21:52his wife, and his father.
0:21:52 > 0:21:56Now he faced a choice - abandon the search,
0:21:56 > 0:22:00or risk exposing his surviving daughter to radiation.
0:22:48 > 0:22:52By just after nine o'clock on the morning of March the 12th,
0:22:52 > 0:22:55the villages around the plant had been evacuated.
0:22:57 > 0:23:01TEPCO ordered the venting teams to go in.
0:23:07 > 0:23:11The plant logs show the first team of two workers set off at 9.04am.
0:23:27 > 0:23:31This footage was filmed by TEPCO seven months later,
0:23:31 > 0:23:33when radiation levels remained dangerous.
0:23:35 > 0:23:39It shows the reactor building where the venting team had to operate.
0:24:15 > 0:24:19Each worker was limited to 17 minutes in the reactor building.
0:24:27 > 0:24:33After nine minutes, the workers found the wheel for opening the vent.
0:24:33 > 0:24:39They inched it open, then pulled back when time ran out.
0:24:39 > 0:24:45More teams followed, each spending just minutes in the reactors.
0:24:45 > 0:24:50One of the workers received a dose of radiation greater than
0:24:50 > 0:24:53the usual limit for five years of work at the plant.
0:25:12 > 0:25:16That afternoon, a thin plume of gas signalled that
0:25:16 > 0:25:19the pressure in the reactor core was falling.
0:25:19 > 0:25:22The venting teams appeared to have saved north-eastern Japan
0:25:22 > 0:25:24from a catastrophic explosion.
0:25:27 > 0:25:32The Fukushima workers now had some power back in the control centre.
0:25:32 > 0:25:35They began to think the worst might be over.
0:25:51 > 0:25:54With the venting complete, the workers could focus on
0:25:54 > 0:25:59getting vitally needed water into the reactor cores.
0:26:00 > 0:26:02Suddenly the ground shook.
0:26:49 > 0:26:53The engineers feared that the reactor core itself had exploded,
0:26:53 > 0:26:55scattering radioactive fuel over the plant.
0:26:58 > 0:27:01In the control centre, they watched the radiation levels
0:27:01 > 0:27:05and waited to learn if they would live.
0:27:29 > 0:27:33Later, in his only authorised comments to the press,
0:27:33 > 0:27:37the plant manager Masao Yoshida revealed that he feared the worst.
0:28:05 > 0:28:09After an hour, the radiation levels stabilised.
0:28:09 > 0:28:12The engineers worked out what had happened.
0:28:12 > 0:28:16Leaking hydrogen had exploded in the roof of the reactor building
0:28:16 > 0:28:19but the reactor core itself was intact.
0:28:35 > 0:28:39In Tokyo, the prime minister's chief cabinet secretary
0:28:39 > 0:28:41was playing down the crisis.
0:28:46 > 0:28:49But behind the scenes, the Japanese government
0:28:49 > 0:28:53knew that the situation was sliding out of control.
0:28:54 > 0:29:00The explosion had halted efforts to get water onto the reactor cores.
0:29:00 > 0:29:03It was now only a matter of time
0:29:03 > 0:29:06before the fuel would melt through into the open,
0:29:06 > 0:29:10spewing out much worse levels of radiation.
0:29:53 > 0:29:58Already a plume of radiation from the gas released in the explosion
0:29:58 > 0:30:00was drifting across Japan.
0:30:01 > 0:30:04The government widened the evacuation zone,
0:30:04 > 0:30:08ordering everyone within 12 miles of the plant to flee.
0:30:10 > 0:30:14Norio Kimura and his surviving daughter were in that danger zone
0:30:14 > 0:30:16when they got the news.
0:30:58 > 0:31:03On the afternoon of March the 12th, a mass exodus began.
0:31:03 > 0:31:09The world started to realise that things were going badly wrong in Fukushima.
0:31:10 > 0:31:15More than 100,000 residents evacuated from the villages around the plant.
0:31:15 > 0:31:19What they didn't know then was that some were fleeing into
0:31:19 > 0:31:23even greater danger, straight into the fallout.
0:31:24 > 0:31:30To this day, what happened remains a source of anger for the evacuees.
0:31:50 > 0:31:57Nozomi Hirouchi and her young family fled their village on the day of the explosion.
0:31:57 > 0:32:03The previous day, her father had been killed in the tsunami.
0:32:24 > 0:32:28That day, a government computer system known as SPEEDI
0:32:28 > 0:32:31predicted that the radioactive fallout would settle
0:32:31 > 0:32:34exactly where some of the evacuees were heading.
0:32:34 > 0:32:38But officials at the nuclear safety agency, NISA,
0:32:38 > 0:32:43say they were unwilling to give the data to the prime minister
0:32:43 > 0:32:46because they weren't sure it was accurate.
0:33:10 > 0:33:13In the district of Tsushima, 20 miles north-west of the plant,
0:33:13 > 0:33:18thousands took shelter, thinking they'd reached safety.
0:33:19 > 0:33:25In fact, radiation levels were higher than at some parts of the nuclear plant itself.
0:33:25 > 0:33:28These doses were not life-threatening
0:33:28 > 0:33:32but have left evacuees desperately worried about their health.
0:33:36 > 0:33:41The Hirouchis' third child was born just after the evacuation.
0:34:07 > 0:34:1165 hours had now passed since the tsunami.
0:34:11 > 0:34:14At the Fukushima plant, the workers faced a new crisis.
0:34:16 > 0:34:20The explosion had set back efforts to get water into the melting cores
0:34:20 > 0:34:22of Reactors One and Two.
0:34:23 > 0:34:26Now Reactor Three was also in meltdown.
0:34:28 > 0:34:31TEPCO needed help.
0:34:31 > 0:34:35A specialist team of soldiers was ordered to the site.
0:34:35 > 0:34:38Another hydrogen build-up meant the Reactor Three housing
0:34:38 > 0:34:41could explode at any moment.
0:35:03 > 0:35:07Colonel Shinji Iwakuma and his team wore suits
0:35:07 > 0:35:10that shielded their bodies from radioactive particles
0:35:10 > 0:35:14but provided no protection against lethal gamma rays.
0:35:16 > 0:35:20Their mission was to inject water directly into the core of Reactor Three.
0:35:57 > 0:36:03The soldiers were now surrounded by lethally radioactive debris.
0:36:03 > 0:36:05They were injured in the blast
0:36:05 > 0:36:10but managed to flee the scene before anyone received a fatal dose.
0:36:37 > 0:36:41Conditions at the plant were now becoming untenable.
0:36:41 > 0:36:45Radiation near one of the reactor buildings had risen
0:36:45 > 0:36:47to 1,000 millisieverts per hour.
0:36:47 > 0:36:54After one hour of exposure at these levels, radiation sickness sets in.
0:36:54 > 0:36:56A few hours would mean death.
0:37:18 > 0:37:23As night fell, the news was passed back to TEPCO HQ in Tokyo.
0:37:23 > 0:37:28The corporation began to consider withdrawing its workers from the plant.
0:37:55 > 0:38:01What happened next has become one of the most controversial chapters in the story of Fukushima.
0:38:01 > 0:38:06That night, the prime minister was woken with a disturbing message.
0:38:07 > 0:38:10He was told that TEPCO planned to withdraw every last worker -
0:38:10 > 0:38:13total surrender.
0:38:13 > 0:38:16There was no mention of leaving some men behind
0:38:16 > 0:38:18to keep control of the plant.
0:38:46 > 0:38:48At that moment in Fukushima,
0:38:48 > 0:38:52the plant manager Masao Yoshida had gathered all the workers together.
0:39:42 > 0:39:46Meanwhile, the prime minister was arriving at TEPCO headquarters in Tokyo,
0:39:46 > 0:39:48determined to stop the withdrawal.
0:39:50 > 0:39:54He demanded to speak to TEPCO's executives.
0:39:54 > 0:39:59Via a video-link, he was watched by the engineers in Fukushima.
0:40:43 > 0:40:46TEPCO's executives still deny that they ever intended
0:40:46 > 0:40:48to withdraw all of their workers.
0:40:50 > 0:40:54That morning, they agreed to keep a skeleton crew at the plant.
0:40:54 > 0:40:59They were to become known as the Fukushima 50.
0:40:59 > 0:41:03For now, they were locked down in the central control room.
0:41:19 > 0:41:22Hundreds of workers were on standby a few miles away -
0:41:22 > 0:41:26ready to lay pipes that could pump water into the reactors.
0:41:28 > 0:41:32But the radiation levels were now too high for them to approach the plant.
0:41:33 > 0:41:36A team of American nuclear specialists,
0:41:36 > 0:41:38who'd just arrived in Japan,
0:41:38 > 0:41:43were fearful that TEPCO and the government were now out of their depth.
0:41:43 > 0:41:47We were given very low numbers of people who were on the site,
0:41:47 > 0:41:50and we knew that that wasn't sufficient
0:41:50 > 0:41:53to do what needed to be done at that time.
0:41:57 > 0:42:01That day, frustrated at the lack of information the Japanese were giving them,
0:42:01 > 0:42:06the Americans decided to fly a surveillance drone over the plant.
0:42:07 > 0:42:10The data they got was disturbing.
0:42:12 > 0:42:14A third hydrogen explosion
0:42:14 > 0:42:19had exposed pools of discarded radioactive fuel to the atmosphere.
0:42:20 > 0:42:24These spent fuel rods were still highly radioactive.
0:42:27 > 0:42:30If the pools boiled dry they could catch fire,
0:42:30 > 0:42:35and the contamination could be even worse than a reactor meltdown.
0:42:35 > 0:42:40We had some pretty clear indication that there was fuel damage occurring
0:42:40 > 0:42:43in the spent fuel pools from lack of water.
0:42:43 > 0:42:47As they were worried about Japanese citizens, we were worried about American citizens
0:42:47 > 0:42:51and we thought, to put all this to rest, put water in there.
0:42:57 > 0:43:01The Japanese prime minister ordered a desperate tactic -
0:43:01 > 0:43:04dumping water on the spent fuel pools from the air.
0:43:07 > 0:43:10The first crew to take off knew that Soviet pilots who'd done this
0:43:10 > 0:43:13during the Chernobyl nuclear accident
0:43:13 > 0:43:16had subsequently died of cancer.
0:43:50 > 0:43:53A reconnaissance mission had been abandoned
0:43:53 > 0:43:57because of high levels of radiation over the reactors.
0:43:57 > 0:44:01Tungsten plates were now bolted to the helicopter.
0:44:02 > 0:44:07The crew knew they had to drop the water on the move, from 300 feet.
0:44:07 > 0:44:10If they went higher, they'd miss.
0:44:10 > 0:44:15If they went lower, they could receive dangerous doses of radiation.
0:45:03 > 0:45:06Their target was beneath them.
0:45:25 > 0:45:27The world watched the mission live
0:45:27 > 0:45:30via a camera placed 20 miles from the plant.
0:46:13 > 0:46:16But on their second mission they missed.
0:46:17 > 0:46:19Other helicopters followed
0:46:19 > 0:46:22but the wind was too strong for accurate aiming.
0:46:24 > 0:46:29The American nuclear team was monitoring the operation.
0:46:29 > 0:46:32We were taking radiation measurements ourselves
0:46:32 > 0:46:37to see, after the drop, did the radiation level go down?
0:46:37 > 0:46:39Er, and it didn't.
0:46:41 > 0:46:45The United States government began to draw up secret plans
0:46:45 > 0:46:48to evacuate 90,000 of its citizens from Japan.
0:46:50 > 0:46:54All British citizens within 50 miles of the plant
0:46:54 > 0:46:56were advised to leave the area.
0:46:56 > 0:47:00The Japanese evacuation zone remained at 12 miles.
0:47:03 > 0:47:06US surveillance now suggested that there were flakes
0:47:06 > 0:47:10of deadly radioactive fuel scattered around the reactors.
0:47:10 > 0:47:14This meant that anyone who even approached the plant
0:47:14 > 0:47:16would be risking their lives.
0:47:21 > 0:47:24Despite the danger, the Japanese government ordered a team
0:47:24 > 0:47:30of Tokyo firefighters to get water into the fuel pools by any means.
0:47:31 > 0:47:35The men had no experience of working in radioactive conditions.
0:48:04 > 0:48:07Their captain went ahead to plot a route.
0:48:07 > 0:48:09But the radiation he was exposed to
0:48:09 > 0:48:12meant he couldn't accompany his men on their mission.
0:48:29 > 0:48:33The plan was for the firefighters to park a truck by the sea
0:48:33 > 0:48:36to suck up water, then lay 800m of hose
0:48:36 > 0:48:40and leave it spraying into the fuel pool.
0:48:46 > 0:48:48Unique footage filmed that night -
0:48:48 > 0:48:51from the front line of the nuclear disaster -
0:48:51 > 0:48:55shows the firefighters preparing to approach the reactors.
0:49:03 > 0:49:07They gave themselves 60 minutes to complete the mission.
0:49:07 > 0:49:11Any longer would expose them to excessive radiation.
0:49:53 > 0:49:58A radiation-monitoring vehicle set off in front of the firefighters.
0:50:07 > 0:50:11Within minutes, the route was blocked.
0:50:11 > 0:50:14The firefighters now had to lay the hose by hand,
0:50:14 > 0:50:16taking readings as they went.
0:50:26 > 0:50:31The alarms on the dosemeters signalled a dangerous increase in radiation.
0:50:49 > 0:50:53A level of 100 millisieverts would mean the firemen would face
0:50:53 > 0:50:59an increased risk of cancer if the mission took longer than an hour.
0:51:19 > 0:51:23After 60 minutes on site, the hoses were finally connected.
0:51:53 > 0:51:55As the firefighters withdrew,
0:51:55 > 0:52:00radiation levels at the plant began to fall.
0:52:00 > 0:52:02The men started back for Tokyo.
0:52:02 > 0:52:06Some had still not told their families what they'd been doing.
0:52:25 > 0:52:29With radiation levels lower, TEPCO seized their chance.
0:52:31 > 0:52:36The hundreds of workers who'd been on standby headed into the plant.
0:52:36 > 0:52:40Their mission was to lay miles of pipes that would channel
0:52:40 > 0:52:44a constant flow of water into the reactor cores.
0:52:44 > 0:52:49They had to work fast in case radiation levels spiked again.
0:53:06 > 0:53:08Once again,
0:53:08 > 0:53:12TEPCO has forbidden these workers from telling their stories.
0:53:12 > 0:53:14But some have chosen to speak out.
0:53:29 > 0:53:33TEPCO says most of their dosemeters were washed away in the tsunami,
0:53:33 > 0:53:37but that they ensured each group of workers had one.
0:53:57 > 0:53:59When the pipes were laid,
0:53:59 > 0:54:04a steady flow of water at last started to cool the reactor cores.
0:54:04 > 0:54:06After days in fear of death,
0:54:06 > 0:54:10the workers in the control centre began to feel hope.
0:54:25 > 0:54:30Weeks of difficult and often dangerous work lay ahead.
0:54:30 > 0:54:32But the fight-back had begun.
0:54:46 > 0:54:50Later, the workers lowered a camera into one of the reactors.
0:54:54 > 0:54:57The flashes of white are caused by gamma radiation.
0:54:59 > 0:55:02TEPCO now thinks that the molten fuel in Reactor One
0:55:02 > 0:55:04finally came to a halt
0:55:04 > 0:55:08in the concrete shell at the bottom of the containment vessel.
0:55:51 > 0:55:54The radiation released by the Fukushima meltdowns
0:55:54 > 0:55:58contaminated hundreds of square miles of north-eastern Japan.
0:56:00 > 0:56:03More than 100,000 people fled the fallout.
0:56:05 > 0:56:09Norio Kimura moved to the mountains of Hakuba.
0:56:10 > 0:56:13Only here, on the other side of the country,
0:56:13 > 0:56:17did he feel his surviving daughter was safe from radiation.
0:56:19 > 0:56:25In the weeks after the tsunami, the bodies of his wife and father had been recovered.
0:56:25 > 0:56:29But his youngest daughter, Yuna, was still missing.
0:56:42 > 0:56:44Four months after the disaster,
0:56:44 > 0:56:48Norio is travelling back to Fukushima.
0:56:50 > 0:56:53An exclusion zone is still in force for 12 miles around the plant.
0:57:00 > 0:57:05Animals abandoned by their owners have starved to death.
0:57:07 > 0:57:10Others roam wild.
0:57:19 > 0:57:22Just two miles from the nuclear power plant,
0:57:22 > 0:57:25the evacuees from this village
0:57:25 > 0:57:29are holding a ceremony for those who died in the tsunami.
0:57:29 > 0:57:32For Norio, it's a chance to say farewell to the life he had
0:57:32 > 0:57:37before the nuclear disaster, and the daughter he had to leave behind.
0:58:25 > 0:58:30The coastline where Norio once lived may be uninhabitable
0:58:30 > 0:58:32for more than 20 years.
0:58:41 > 0:58:45Subtitles by Red Bee Media Ltd