Almost three years on from the Fukushima nuclear disaster and safety concerns about the expansion of nuclear power plants, especially in developing economies, run high.
"Sitting here in Singapore, what the government is concerned about is what our neighbors - Indonesia, Malaysia, Vietnam [and] the Philippines will do on nuclear energy. What if they go for it? Vietnam is," said Philip Andrews-Speed, principal fellow and head of energy security at the National University of Singapore's (NUS) Energy Studies Institute.
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The devastating earthquake and tsunami that hit Japan in March 2011 soon developed into a nuclear catastrophe as one system after another at the Fukushima Daiichi nuclear power plant failed. Three of the plant's six reactors suffered meltdowns, releasing deadly radiation into the sea and air.
Following Fukushima, many countries put their nuclear energy plans under review. Western Europe saw 11 reactors close between 2010 and 2012, the highest among all regions, market research firm Euromonitor said in a report in January.
In contrast, worries about growing demand and the rising price of fossil fuels has encouraged emerging countries to expand plans for nuclear power. Brazil, Russia, India and China, the group often referred to as the BRICs, alone accounted for 44 of the 62 nuclear reactors under construction globally in 2012, according to Euromonitor.
"There's deep skepticism about whether Southeast Asian regulators can be trusted to ensure that exacting maintenance and safety standards are met. They look at the Japanese — who are perceived as thoroughly diligent and obsessive about their work — and ask: if the Japanese can't prevent what happened in Fukushima, how can we?," said Shahriman Lockman, a senior analyst at the Institute of Strategic and International Studies in Malaysia.
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"To a certain extent, you can't blame people for their anxieties. At the same time, the focus on Fukushima — which took place as a result of a confluence of factors that are unlikely to happen with new nuclear reactors — is very unfortunate," he added.
Some experts believe the development of nuclear power plants in emerging economies such as India or Vietnam is safer than it might appear.
For starters, the technology used is new. Second, there are stringent safety standards. Vietnam for instance, may delay the construction of its first nuclear power plant to ensure safety and economic efficiency until 2020, state media quoted the country's prime minister as saying last month.
"We have to be careful about making generalizations and my view is that developing economies do follow stringent safety rules," said Atam Rao, who spent 31 years with General Electric working on the design and development of nuclear plant designs.
"There is a sharing of information that will prevent future disasters. People realize that there are global repercussions every time there is an accident," added Rao, also a former head of Nuclear Power Technology Development at the International Atomic Energy Agency in Vienna. "There was a huge effort after Fukushima, with a revising of plans and that sometimes gets lost in the debate."
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Experts add that when it comes to regulation of nuclear plants, the relationship between regulators and plant operators is something to watch whether nuclear plants are in a developed or emerging economy.
For example, in South Korea, Asia's number four economy, government officials said in October last year that nuclear reactors have been abruptly closed 128 times in the past decade because of faulty parts amid a scandal over forged safety documents.
Others argue that while governments may set a high bar for safety standards, these may be harder to implement at a middle-ranking level.
"If you want to build nuclear plants in places like Vietnam, which do not have the governance, which do not have the infrastructure and also face rising sea levels as well as extreme weather events, against which concentrated power is vulnerable, to sell them that stuff [nuclear power] is morally suspect," said Andrew DeWit, a professor of policy studies at Rikkyo University in Tokyo.
Thailand said late last year that its new Power Development Plan provides for the construction of new coal-fired and nuclear power plants in the next 20 years.
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Hungary meanwhile said recently that it would expand its only nuclear power plant, more than doubling its capacity in a move that is expected to become hot election topic when voters go to the polls later this year.
According to the World Nuclear Association (WNA), an agreement for up to $9 billion worth of financing was signed in November 2011 between Vietnam and Russia to fund nuclear power development, and a second agreement for $500 million loan covered the creation of a nuclear science and technology centre.
Total investment in nuclear power plants in China will reach $75 billion by 2015, according to data from the China National Nuclear Corporation cited by the WNA.
The elephant in the room
For Andrews-Speed at the NUS, China is the "elephant in the room" in terms of risks from nuclear energy because of the scale of its plans.
China had 15 nuclear reactors in operation in 2012 and 26 reactors under construction, the highest in the world, Euromonitor said. According to the World Nuclear Association, China has plans to begin the construction of more nuclear reactors over the coming years to give it a four-fold increase in nuclear capacity by 2020.
"China is a country I worked on for more than 20 years. It has a real problem in all energy and resource and environment sectors of regulation and safety standards. They can draft the rules but are they capable of implementing them?," said Andrews-Speed.
"Now, they haven't had any major nuclear incidents in the past 10 years when they've had nuclear plants. But then they've had a relatively small number of plants and now you have a multiplication of plants," he added.
— By CNBC.Com's Dhara Ranasinghe; Follow her on Twitter @DharaCNBC