In the Philippines, Fukushima atomic accident gave pause to efforts to revive the country's white elephant, the Bataan Nuclear Power Plant, which was built in the early 1980s but never went into operation because it sits on a tectonic fault and volcano.
After the 1986 Chernobyl nuclear disaster, Vietnam suspended its nuclear plans and waited for more than a decade before reviving them.
But Vietnam was undeterred by last year's Fukushima nuclear meltdown in Japan, the world's worst atomic accident since Chernobyl, and is racing ahead with plans to start construction of its first reactor in 2014, which should go online six years later.
It aims to follow that up with another 14 reactors by 2030.
At least five other members of the 10-nation Association of South East Asian Nations (ASEAN) are studying nuclear power as an option to meet demand for energy in the fast-growing region of 600 million people.
Proponents say atomic energy is unavoidable for the region, and the prohibitive cost of alternatives will help to drive the sector.
Vietnam, Indonesia, Malaysia, the Philippines, Thailand and Singapore are among some 35 countries considering going down the nuclear path, likely doubling the number of operational reactors in the next few decades, according to Lloyds Register.
But even the most ambitious plans will run up against barriers and constraints.
In most Southeast Asian countries where there is interest in nuclear power, politics are holding it back.
Indonesia's National Atomic Energy Agency has been researching reactors for more than four decades and preparing the human resources, but the political will is lacking.
"Everything is ready here, except for a political decision," said Ferhat Aziz, a spokesman for the agency. "Too many people think it is too dangerous and too expensive so the key challenge is in people's minds."
The story is similar in Thailand where, like Indonesia, energy demand outstrips supply. The Thai Energy Ministry is drafting a plan that could see a nuclear facility go into operation in 2026.
"The nuclear power plant project is still in the country's power development plan, but whether it will come into shape depends on the acceptance of the public," said Mongkol Sakulkao, deputy head of policy and planning at state-run Electricity Generating Authority of Thailand.
"If it is delayed further, they'll come up with plans to find alternative fuels to replace nuclear."
In Malaysia, the government has quietly put a proposal to build two 1,000 MW nuclear power plants "on the back burner," said a senior government source.
The decision came after environmentalists targeted a plan by Australian rare earths miner Lynas Corp to commission a processing plant in central Malaysia that would have to dispose of radioactive waste.
The nuclear plan was floated by Energy Minister Peter Chin in December 2010 "to correct an imbalance" in energy sources.
Malaysia relies heavily on fossil fuels for electricity generation with gas accounting for more than 60 percent and coal the rest. Others in the region face similar imbalances.
"It may be revisited some time down the line," said the government source who declined to be identified because of the sensitivity of the issue.
Singapore is in the earliest stages of considering how nuclear power might fit into its power mix, but seems unlikely to build a plant on its own territory.
And in the Philippines, Fukushima gave pause to efforts to revive the country's white elephant, the Bataan Nuclear Power Plant, which was built in the early 1980s but never went into operation because it sits on a tectonic fault and volcano.
If Vietnam can follow through with its plans, it will be one of the first new entrants to the nuclear club since the Japanese meltdown. That may help explain why participants at the "World Nuclear Power Briefing 2012" in Hanoi late last month seemed most interested in a session on Vietnam.
"I think Vietnam is in a good position because it's doing this right now after Fukushima. It's not wavering," said Lady Barbara Judge, chairman emeritus of the UK Atomic Energy Authority who attended the conference.
The government has signed deals with Japan and Russia to supply the Ninh Thuan 1 and 2 reactors, although it has not decided what type to buy.
Judge said Vietnam would be an important opportunity for both countries to showcase their wares.
But to get there it will take more than political will. One of the biggest global bottlenecks, and one that will likely slow things down in Vietnam, is getting qualified personnel who can run reactors and regulate them.
"In order to operate a nuclear plant those people in charge ideally require 15 to 20 years of experience, and 15 or 20 years of experience only comes with 15 or 20 years of work. You can't really fast-track that considerably," said Richard Clegg, Global Nuclear Director at Lloyd's Register.
There is also a rule of thumb in the industry that each reactor requires about 15 inspectors.
Vietnamese technical officials understand the challenges. The 2020 start date "is really difficult for us now," said Pham Minh Tuan, deputy director of the Ninh Thuan project.
And the wish to have nuclear account for 20-25 percent of all energy consumed in Vietnam by 2050?
"It's a very ambitious target," he said.