Mikio Watanabe holds a portrait of his late wife Hamako under photographs of his ancestors and Hamako (top R) at his home at Yamakiya district in Kawamata town, Fukushima prefecture June 23, 2014. In July 2011, nearly four months after the massive earthquake and tsunami that triggered a series of catastrophic failures at the Fukushima Daiichi nuclear plant, Hamako Watanabe returned to her still-radioactive hilltop home, doused herself in kerosene and set herself on fire. She left no suicide note, but her husband Mikio, who discovered her charred body, says plant operator Tokyo Electric is directly responsible. A district court in Fukushima is expected to rule in late August on Watanabe's lawsuit, which Tokyo Electric (Tepco) is contesting. Watanabe's house is still in an exclusion zone, where traffic is restricted to former residents and decontamination crews and he regularly commutes to maintain the empty home. Picture taken June 23, 2014. REUTERS/Issei Kato 

Wearing a protective suit and a mask, U.S. Ambassador to Japan Caroline Kennedy (L) listens to Naohiro Masuda (3rd R), an executive of Japan's Tokyo Electric Power Co. (TEPCO), during her visit to the central control room for the unit one and unit two reactors of the tsunami-crippled Fukushima Daiichi nuclear plant at Okuma town in Fukushima prefecture May 14, 2014. Kennedy pledged U.S. support for the clean-up at Japan's tsunami-wrecked Fukushima Daiichi nuclear power plant on Wednesday after her first visit to the site. REUTERS/Toru Yamanaka/Pool 

Tsunami-crippled Fukushima Daiichi nuclear power plant operator Tokyo Electric Power Co. (TEPCO) volunteers removed ice and snow and levelled dirt in a playground, as seen through a window at a Miyakoji child care center at Miyakoji area in Tamura, Fukushima prefecture, April 1, 2014. People in Japan on Tuesday began their first homecomings in three years to a small area evacuated after the Fukushima disaster, but families are divided as worries about radiation and poor job prospects have kept many away. The reopening of the Miyakoji area of Tamura, a city 220 km (140 miles) northeast of Tokyo and inland from the wrecked Fukushima nuclear station, marks a tiny step for Japan as it attempts to recover from the 2011 disasters. REUTERS/Issei Kato 

A doctor conducts a thyroid examination on a five-year-old girl as her older brother and a nurse take care of her at a clinic in a temporary housing complex in Nihonmatsu, west of the tsunami-crippled Fukushima Daiichi nuclear power plant, Fukushima prefecture February 27, 2014. March 11 marks the third anniversary of the earthquake and tsunami that devastated Japan's Fukushima Daiichi nuclear power plant. In Koriyama, a short drive from the crippled Fukushima nuclear plant, the city recommended shortly after the disaster that children up to two years old not spend more than 15 minutes outside each day. Those aged 3 to 5 should limit their outdoor time to 30 minutes or less. The limits were lifted last year, but many kindergartens and nursery schools continue to obey them even now in line with the wishes of worried parents. An annual survey by the Fukushima prefecture Board of Education found that children in Fukushima weighed more than the national average in virtually every age group. The cause seems to be a lack of exercise and outdoor activity. Picture taken February 27, 2014. REUTERS/Toru Hanai 

Members of the media and Tokyo Electric Power Co. (TEPCO) employees, wearing protective suits and masks, walk alongside a wall lined with thousands of paper cranes inside the main anti-earthquake building at the tsunami-crippled TEPCO's Fukushima Daiichi nuclear power plant in Fukushima prefecture March 10, 2014, a day before the third anniversary of the March 11, 2011 earthquake and tsunami. Members of the media were allowed into the plant on Monday a day before the anniversary of the disaster, which triggered the world's worst nuclear crisis since Chernobyl. REUTERS/Toru Hanai 

A vending machine, brought inland by a tsunami, is seen in a abandoned rice field inside the exclusion zone at the coastal area near Minamisoma in Fukushima prefecture September 21, 2013. In 2011 a massive earthquake and tsunami wrecked the Fukushima nuclear plant, resulting in a meltdown that became the world's worst atomic crisis in 25 years. About 160,000 people living near the plant were ordered to move out and the government established a 20-km compulsory evacuation zone. The operator of the plant, Tokyo Electric Power Co, is struggling to contain contaminated water at the site 240 km north of Tokyo. There have been multiple leaks and glitches over the last two and a half years. Picture taken September 21, 2013. REUTERS/Damir Sagolj 

Firefighters from Kyoto pay respect to victims as they visit the tsunami destroyed coastal area of the evacuated town of Namie in Fukushima prefecture September 15, 2013. Namie's more than 20,000 former residents can visit their homes once a month with special permissions but are not allowed to stay overnight inside the exclusion zone. A total of 160,000 people were ordered to leave their homes around Daiichi plant after the government announced the evacuation following the nuclear disaster in March 2011. Picture taken September 15, 2013. REUTERS/Damir Sagolj 

A workers stands in front of an 18-meter (59 ft) high and 1.6 km (1 mile) long tsunami defence wall at Chubu Electric Power Co.'s Hamaoka Nuclear Power Station in Omaezaki, Shizuoka Prefecture May 17, 2013. Chubu Electric is spending at least $1.5 billion on safety upgrades at its Hamaoka nuclear plant southwest of the Japanese capital, to reduce the risk of a repetition of the disaster that hit Tokyo Electric's Fukushima station, when an earthquake and tsunami caused three reactor meltdowns. REUTERS/Toru Hanai 

Wakana Kumagai, 7, visits the spot where her house, which was washed away by the March 11, 2011 tsunami, used to stand in Higashimatsushima, Miyagi prefecture March 11, 2012, to mark the first anniversary of an earthquake and tsunami that killed thousands and set off a nuclear crisis. Kumagai's father Kazuyuki called his wife Yoshiko just after the March 11, 2011 earthquake to tell her to take the children to Omagari elementary school which was serving as a shelter. He was found near the shelter four days after the tsunami, Yoshiko said. REUTERS/Toru Hanai 

Buddhist monks offer prayers for victims of the March 11, 2011 earthquake and tsunami at Kitaizumi beach in Minamisoma, Fukushima prefecture, some 25 km (15 miles) from the tsunami-crippled Fukushima Daiichi nuclear power plant March 10, 2012, a day before the disaster's one-year anniversary. The magnitude 9.0 earthquake on March 11 last year unleashed a tsunami that killed about 16,000 and triggered the world's worst nuclear crisis since Chernobyl. About 326,000 people are still homeless and nearly 3,300 remain unaccounted for. REUTERS/Yuriko Nakao 

The shards of glass of a broken window frame a general view of an area damaged by the March 11, 2011 earthquake and tsunami in Rikuzentakata, Iwate Prefecture March 9, 2012, ahead of the one-year anniversary of the disasters. REUTERS/Carlos Barria 

A man looks for his photographs at a collection centre for items which were found in the rubble of an area devastated by the March 11, 2011 earthquake and tsunami in Sendai, Miyagi prefecture March 9, 2012, ahead of the one-year anniversary of last March 11 earthquake and tsunami. More than 250,000 photographs and personal belongings are displayed at the centre for owners to recover. REUTERS/Toru Hanai 

Students walk near a geiger counter, measuring a radiation level of 0.12 microsievert per hour, at Omika Elementary School, located about 21 km (13 miles) from the tsunami-crippled Fukushima Daiichi nuclear power plant, in Minamisoma, Fukushima prefecture, March 8, 2012, ahead of the one-year anniversary of the March 11 earthquake and tsunami. The reopened elementary school, which is the nearest one located to the crippled nuclear power plant, had 205 students before the March 11, 2011 disasters. However, only 91 students remained following its reopening on October 17, 2011. REUTERS/Toru Hanai 

ATTENTION EDITORS: PICTURE 4 OF 15 FOR PACKAGE 'TSUNAMI SURVIVORS REUNITED' - Yuko Sugimoto is pictured holding a picture of herself and standing in the same place she stood in March 13, 2011 after the area was hit by an earthquake and tsunami in Ishinomaki, Miyagi prefecture in northern Japan February 22, 2012. Sugimoto was pictured last year, wrapped in a blanket in front of a pile of debris as she looked for her son Raito who was missing. Her picture became an iconic image of the 9.0 magnitude earthquake that devastated Japan a year ago. Picture taken February 22, 2012. REUTERS/Yuriko Nakao 

A worker screened for radiation as he enters the emergency operation center at Tokyo Electric Power Co. (TEPCO)'s tsunami-crippled Fukushima Daiichi nuclear power plant in Fukushima prefecture February 20, 2012. Members of the media were allowed into the plant on Monday ahead of the first year anniversary of the March 11, 2011 tsunami and earthquake for the second time since the disaster, which triggered the world's worst nuclear crisis since Chernobyl. REUTERS/Issei Kato 

A view of the destroyed roof of the No.3 reactor building of Tokyo Electric Power Co. (TEPCO)'s tsunami-crippled Fukushima Daiichi nuclear power plant is seen in Fukushima prefecture February 20, 2012. Members of the media were allowed into the plant on Monday ahead of the first year anniversary of the March 11, 2011 tsunami and earthquake for the second time since the disaster, which triggered the world's worst nuclear crisis since Chernobyl. REUTERS/Issei Kato 

ATTENTION EDITORS - THIS IMAGE IS 1 OF 22 TO ACCOMPANY A PICTURE PACKAGE ON THE EVACUATED TOWNS INSIDE THE 20KM EXCLUSION ZONE AROUND THE FUKUSHIMA DAIICHI NUCLEAR POWER PLANT. SEARCH KEYWORD "FUKUSHIMA" TO SEE ALL IMAGES PXP900-921.

An empty shopping street is seen in Tomioka town, inside the exclusion zone of a 20km radius around the crippled Fukushima Daiichi nuclear power plant, Fukushima prefecture, January 15, 2012. The Fukushima Daiichi nuclear power plant was hit on March 11, 2011 by a tsunami that exceeded 15 metres in some areas. The tsunami knocked out the plant's cooling systems, resulting in meltdowns of nuclear fuel, and became the world's worst atomic crisis in 25 years. The government announced in December that reactors at the plant had reached a state of cold shutdown, a milestone in cleanup efforts and a pre-condition for allowing the return of about 80,000 residents evacuated from a 20km (12 miles) radius of the Daiichi plant. The government also said it would draw up new evacuation zones by the end of April, and areas where annual radiation levels are currently higher than 50 millisieverts would not be deemed suitable for living for at least five years. Picture taken January 15, 2012. REUTERS/Stringer 

A boy prays for victims of the March 11 earthquake and tsunami after offering a flower during a memorial service in Minamisanriku town, Miyagi prefecture, six months after the area was devastated by a 9.0 magnitude earthquake and tsunami, September 11, 2011. REUTERS/Toru Hanai 

A Japanese national flag flutters near an area where debris cleaned up after from the March 11 earthquake and tsunami is being collected in Ofunato, Iwate prefecture, September 9, 2011, some six months since the disaster. REUTERS/Toru Hanai 

Satsuko Yatsuzaka (84) holds a therapeutic robot named Paro at the Suisyoen retirement home, about 30 km (19 miles) south of the tsunami-crippled nuclear plant in Iwaki, Fukushima prefecture, July 28, 2011. For some elderly survivors of Japan's march earthquake and tsunami, comfort comes in the form of a small white robotic seal named Paro. The residents of the nursing home came back from a nearly two-month-long evacuation since the nuclear crisis in Fukushima. Picture taken July 28, 2011 To match Reuters Life! ROBOT-SEAL/ REUTERS/Kim 

New students attend their first homeroom activity after a entrance ceremony at Kamaishi elementary school in Kamaishi, Iwate prefecture, after the area was devastated by the March 11 earthquake and tsunami, April 20, 2011. Nineteen new students took part in the entrance ceremony which was held 13 days late due to the March 11 earthquake and tsunami.
REUTERS/Toru Hanai 

A volunteer cleans a family photo that was washed by the March 11 earthquake and tsunami as baby photos are placed to dry at a volunteer centre in Ofunato, Iwate prefecture, April 12, 2011. REUTERS/Toru Hanai 

A police officer in protective suit walks past a damaged house while searching for bodies in Minamisoma, about 18 km (11 miles) from the damaged Fukushima nuclear power station, Fukushima prefecture, April 11, 2011. Residents of a Japanese village well-outside of an evacuation zone set around a crippled nuclear power plant have been told to prepare to be evacuated, a local official said on Monday. The operator of the crippled Fukushima Daiichi nuclear complex said there were no irregularities at the plant following a magnitude 7.1 earthquake that hit northeast Japan on Monday. REUTERS/Kim Kyung-Hoon 

A picture frame and water marks are seen over the wall of a kindergarten destroyed by the March 11 earthquake and tsunami in Ishinomaki, northern Japan, April 7, 2011. Japan's neighbours sounded increasingly alarmed over the risk of radiation from the crippled Fukushima nuclear power plant, while figures showed the number of foreign visitors to the country had slumped during what should be the peak tourism season. REUTERS/Carlos Barria 

Japanese yen banknotes, which were found in a damaged store, are seen in Ishinomaki, northern Japan, April 3, 2011, after the area was devastated by a magnitude 9.0 earthquake and tsunami on March 11. REUTERS/Kim Kyung-Hoon 

A man walks at a residential area destroyed by the March 11 earthquake and tsunami in Ishinomaki, northern Japan March 31, 2011. Pressure grew on Thursday for Japan to expand an evacuation zone round its stricken nuclear plant where radiation hit 4,000 times legal limits in nearby sea and hindered the battle to contain the world's worst atomic crisis since Chernobyl. REUTERS/Carlos Barria 

A house and vehicles damaged by the March 11 earthquake and tsunami are seen in Ishinomaki, northern Japan March 31, 2011. Pressure grew on Thursday for Japan to expand an evacuation zone round its stricken nuclear plant where radiation hit 4,000 times legal limits in nearby sea and hindered the battle to contain the world's worst atomic crisis since Chernobyl. REUTERS/Carlos Barria 

A police officer closes the door of a bus with wading pants hanging from its windows, in earthquake- and tsunami-hit Ishinomaki, Miyagi Prefecture, northeastern Japan March 29, 2011. REUTERS/Yuriko Nakao 

A fisherman reacts as he looks at his boat, which was destroyed by March 11's magnitude 9.0 earthquake and tsunami, in Yamada town, Iwate prefecture March 27, 2011. Japan is still grappling with relief and recovery efforts after the massive earthquake and tsunami devastated northeast Japan and crippled a nuclear power station, raising the risk of uncontrolled radiation. REUTERS/Carlos Barria 

Ducks swim past a submerged vehicle after the earthquake and tsunami in Yamada town, Iwate Prefecture in northern Japan, March 24, 2011. The Japanese government on Wednesday estimated the direct damage from a deadly earthquake and tsunami that struck the country's northeast this month at as much as $310 billion, making it the world's costliest natural disaster. REUTERS/Carlos Barria 

A woman makes a bed in a relative's house where she and other 31 family members found shelter in Rikuzentakata March 23, 2011, after the area was devastated by a magnitude 9.0 earthquake and tsunami, REUTERS/Damir Sagolj 

Emergency workers search through debris near the seaside in Rikuzentakata, Iwate prefecture, March 19, 2011. The area was devastated by a magnitude 9.0 earthquake and tsunami on March 11. REUTERS/Aly Song 

A doctor talks to evacuees from the vicinity of Fukushima nuclear plant, at an evacuation center set in a gymnasium in Yamagata, northern Japan, March 19, 2011, eight days after Japan's devastating earthquake and tsunami. REUTERS/Yuriko Nakao 

A man checks lists of evacuees at an evacuation center near a devastated area hit by massive earthquake and tsunami which struck Japan a week earlier, in Rikuzentakata, north Japan, March 18, 2011. REUTERS/Kim Kyung-Hoon 

Survivors react after collecting their belongings at their destroyed house in a village hit by an earthquake and tsunami in Otsuchi, northeast Japan March 17, 2011. REUTERS/Lee Jae-Won 

Policemen carry the bodies of victims retrieved from the debris in Rikuzentakata, Iwate Prefecture, days after the area was devastated by a magnitude 9.0 earthquake and tsunami, March 16, 2011. REUTERS/Adrees Latif 

A girl who has been isolated at a makeshift facility to screen, cleanse and isolate people with high radiation levels, looks at her dog through a window in Nihonmatsu, northern Japan, March 14, 2011, after a massive earthquake and tsunami that are feared to have killed more than 10,000 people. REUTERS/Yuriko Nakao 

Elderly people warm themselves with blankets at a Japanese Red Cross hospital after being evacuated from the area hit by tsunami in Ishinomaki March 13, 2011. Japan faced a growing humanitarian crisis on Sunday after its devastating earthquake and tsunami left millions of people without water, electricity, homes or heat. REUTERS/Damir Sagolj 

Officials in protective gear check for signs of radiation on children who are from the evacuation area near the Fukushima Daini nuclear plant in Koriyama, March 13, 2011. Japanese Chief Cabinet Secretary Yukio Edano confirmed on Saturday there has been an explosion and radiation leakage at Tokyo Electric Power Co's (TEPCO) Fukushima Daiichi nuclear power plant. The biggest earthquake to hit Japan on record struck the northeast coast on Friday, triggering a 10-metre tsunami that swept away everything in its path, including houses, ships, cars and farm buildings on fire. REUTERS/Kim Kyung-Hoon