Fukushima Daiichi Nuclear Power Plant is seen on March 6 over fishing boats stranded by the 2011 tsunami triggered by a 9-magnitude earthquake in Namie, Fukushima Prefecture. Photo: CFP

Takashi Sato, a 12-year-old boy, is the only pupil at Onami Elementary School, which lies 57 kilometers from the Fukushima nuclear power plant. On Thursday, he attended a graduation ceremony held only for him.

Soon after the meltdowns at the power plant following the 9-magnitude earthquake and tsunami in 2011, the school, which originally had 41 students, was attended by just Takashi. Others transferred to different schools for fear of radiation, the Sankei Shimbun reported.

For family reasons, Takashi couldn't move elsewhere, so everyday he was accompanied by his teacher and several school employees through classes and meals. Following Takashi's graduation, the school will soon be closed.

Three years on, the Japanese are still clouded by the impact of the world's worst nuclear accident since Chernobyl in 1986. Two days before March 11, the third anniversary of the Fukushima accident, tens of thousands of Japanese citizens assembled in Tokyo to voice their anger at the country's nuclear industry and Prime Minister Shinzo Abe's government, which intends to restart Japan's nuclear reactors after being idle for two years. Such protests are nothing new in Japan.

While Japanese people are haunted by their nuclear plants, the country's massive nuclear stockpile disturbs the outside world.

Nuclear stocks

As the only victim of nuclear bombs in human history, Japan possesses 331 kilograms of mostly weapons-grade plutonium offered by the US during the Cold War era for research purposes. The highly-concentrated plutonium can produce 40 to 50 nuclear weapons.

The US has repeatedly asked Japan to return the plutonium for the sake of nuclear security. Tokyo rejected initially, citing that the nuclear stock is needed for fast reactor research, but it finally gave in to the demands of its ally in January, according to the Kyodo News Agency.

At the Nuclear Security Summit in the Netherlands, Abe and US President Barack Obama said Monday that Japan would turn over the nuclear stockpile to the US to be downgraded and disposed of, which will "help prevent unauthorized actors, criminals, or terrorists from acquiring such materials," Reuters reported. The plutonium would be prepared for "final disposition."

"This (the plutonium) is some of the material in Japan that would be the greatest danger if ever stolen by terrorists, so it is a great thing that it will be shipped out, and combined with other stocks that already require heavy guarding in the US," said Matthew Bunn, a professor and a principal investigator at the Kennedy School's Project on Managing the Atom, Harvard University. 

However, what triggered concerns is not just the plutonium originally from the US. Japan also possesses more than 1.2 tons of highly enriched uranium and 44 tons of low-quality plutonium from reprocessing spent nuclear fuel, far exceeding its need for nuclear energy.

Like uranium, plutonium can be used in nuclear power plants as fuel, but it can also serve as material for nuclear bombs.

Bunn explained that about 35 tons of this plutonium is in France and Britain, so Japan would eventually arrange for the two countries to either use it as fuel or dispose of it along with their own stocks of separated plutonium.

"The main focus should be on the 9 tons of separated plutonium that exists within Japan," Bunn told the Global Times. 

In addition, Japan will start operation of a nuclear fuel reprocessing facility as early as October in Rokkasho, Aomori Prefecture. As one of the world's largest plutonium production facilities, the new plant could produce about 8 tons of plutonium annually, enough to make 1,000 Nagasaki-type bombs, according to the International Panel on Fissile Materials.

Bunn noted that Japan may face serious problems trying to use up its existing stock of separated plutonium, let alone the additional plutonium to be separated at Rokkasho.

Japan's 48 nuclear plants have all been offline following the Fukushima disaster. A recent survey by Japan's national broadcaster NHK showed that 76 percent of the respondents are in favor of reducing or scrapping nuclear reactors. 

Unabated concern

Does one need so much sensitive nuclear material for peaceful use? Should one keep excessive weapons-grade nuclear material? How can Japan ensure a balance between the demand and supply of nuclear materials? China's foreign ministry spokesman Qin Gang threw out a string of questions regarding Japan's nuclear stockpile on March 4. These concerns have been voiced on multiple occasions.

Given the absence of any concrete plan to use such massive nuclear stocks and the Abe administration's right-leaning tendency that sparked suspicion of a return to militarism, the concerns from China as well as the outside world are not ungrounded.

Steve Fetter, formerly assistant director on the Office of Science and Technology Policy in the White House, noted at a symposium in January that Japan's plutonium accumulation suggests to other countries that it is developing "a type of nuclear deterrent."

"As Russia, China and even North Korea have nuclear weapons and, meanwhile, the US is not as reliable as expected, the idea of nuclear deterrence is enticing to Japan," a Japanese media expert, who requested anonymity, told the Global Times.

"In fact, when Japan started developing nuclear plants after WWII, it had the intention to grow its capability of building nuclear weapons in this process. Now Japan can use this to bargain with the US for a bigger nuclear umbrella," Feng Zhaokui, a senior Japan expert at the Chinese Academy of Social Sciences, told the Global Times.

But making nuclear weapons would not find approval from Japanese people as most of them would like to live a peaceful life or are "obsessed" with peace, the Japanese expert said, adding some politicians may have the nuclear  arsenal thought while they are afraid to speak out for the memory of Nagasaki and Hiroshima.

Yet Japanese Foreign Minister Fumio Kishida hinted last month that Japan would allow the US to bring nuclear weapons into the country when events that seriously threaten its security occur.

This suggests that Japan's longstanding principle of not possessing, producing and allowing nuclear weapons within the territory doesn't have much credibility, Feng noted.