It is also necessary, he said, to undertake a renewed cost-benefit analysis of nuclear energy. "Nuclear power will likely continue to be an important resource for many nations and can be a part of a low-carbon-emission energy mix – but it has to become credibly safe, and globally so."

The Secretary-General added that he will launch a UN system-wide study on the implications of the accident at Fukushima.

Lastly, he stressed the need to build a stronger connection between nuclear safety and nuclear security, noting that while the two are distinct issues, boosting one can bolster the other.

"At a time when terrorists and others are seeking nuclear materials and technology, stringent safety systems at nuclear power plants will reinforce efforts to strengthen nuclear security," he said. "A nuclear power plant that is safer for its community is also one that is more secure for our world."

Together, these practical steps can help reassure the global public and better prepare the world's people and the planet for the energy challenges of the 21st century, Mr. Ban stated.

"By joining forces, we can make sure that the tragedies of Chernobyl and Fukushima are a thing of the past, not a harbinger of the future."

Concerning the Fukushima Daiichi nuclear power plant, Denis Flory, the IAEA Deputy Director General for Nuclear Safety and Security, told reporters in Vienna that although the situation remains very serious, there are early signs of recovery in some functions, such as electrical power and instrumentation.

On Sunday, Japan's Ministry of Economy, Trade and Industry announced that TEPCO, the company that owns the power plant, issued a "Roadmap" towards bringing the stricken facility under control. The roadmap outlines 63 measures to be taken in two steps over a period of six to nine months.

Mr. Flory said that IAEA had also received information that TEPCO has provided a plan to Japan's Nuclear and Industrial Safety Agency (NISA) for the transfer of highly contaminated water from the basement floor of the turbine building of the plant's unit 2 to the main building of the radioactive waste treatment facilities to reduce the risk of the stagnant waste water being discharged to the environment.