In the wake of Japan's nuclear emergency, many people are asking if nuclear energy is necessary to feed America's energy appetite. And the answers might not be clear for some time.

To get a sense of the scope of these challenges, we focus on Vermont as a microcosm for the nation's nuclear conversation. Vermont gets 1/3 of its electricity from the Yankee nuclear plant, a facility that is a near twin in design and age to the crippled reactors in Japan. And U.S. federal authorities have decided to extend the life of Vermont Yankee by another 20 years, despite strong opposition.

[SEN. BERNIE SANDERS (I) VERMONT] It makes me feel that much stronger that the idea of keeping a 40-year-old reactor open for another 20 years, to be 60, makes zero sense at all.

[ASSURAS] "energyNOW!" Chief Correspondent Tyler Suiters went to Vermont to get a sense of that debate. Tyler?

[SUITERS] Thalia, one of the things I learned is that the name "Vermont Yankee" can be either a blessing or a curse, it all depends on who's saying it. And if opponents of the plant get their way, next year, Vermont will find out what it's like to live without nuclear power. Which raises a question for all of us -- could the entire country go without nuclear power?

The first day of spring in Vermont brought a snowstorm and a history lesson.

[LARRY SMITH, VERMONT YANKEE NUCLEAR PLANT] It's original paint, and these are the original fireplaces.

[SUITERS] This was on in the 18th century when this was constructed?

[SMITH] That's all original. Probably more lead-based paint than you want to know.

[SUITERS] What was the lieutenant governor's home during the 18th century is now a training center for the Vermont Yankee nuclear plant, maybe the most controversial nuclear plant in the entire country right now.

[SMITH] Well, it's polarized. It's a political issue, certainly. This town, Vernon, the host community, has always, and continues to be, very supportive of Vermont Yankee, and especially the license renewal.

[SUITERS] You get a very different opinion six miles up the road, in a Brattleboro church. A rally supporting renewable energy. That's where I met environmental advocate James Moore.

[JAMES MOORE] This is what we're talking about. It's safe energy for our children's future. That's what it boils down to.

[SUITERS] Moore's point -- 40 years of operation are long enough for a nuclear plant.

[JAMES MOORE, VERMONT PUBLIC INTEREST RESEARCH GROUP] What we're looking at with Vermont Yankee is one of the oldest nuclear power plants in the country. Everything has its time.

[SUITERS] And with Vermont Yankee, we're talking about one single nuclear reactor in one single state. The whole of the U.S. has 104 commercial nuclear power reactors spread across 31 states, more reactors than any other country, producing twice as much power as any other country. Too much to simply turn off.

[PATRICK MOORE, CASENERGY COALITION] No, the United States could not just shut down 20% of its baseload electricity production overnight.

[SUITERS] And that comes from a founding member of Greenpeace, maybe the best-known antinuclear group there is. But Patrick Moore changed his mind, drawing a line between nuclear energy and weapons. He now co-chairs a pro-nuclear coalition.

[PATRICK MOORE] If we hadn't made the mistake in the environmental movement of being against nuclear energy, of kind of lumping it in with nuclear weapons, as if everything nuclear was evil, there would be a lot more nuclear plants in the U.S. today.

[SUITERS] Vermont has just the one, enough for the country's smallest energy-using state, but take away that nuclear plant...

[SMITH] We supply 1/3 of the energy to the state of Vermont. So that's 285 megawatts right now.

[SUITERS] And if that were offline, how would the state replace that?

[SMITH] Well, it has to come from somewhere.

[SUITERS] And a lot of it came from burning oil, until the 1970s oil embargo. That's part of the reason we started building so many nuclear plants back then. Today, almost half the country's electricity comes from coal, as do most of the power sector's carbon emissions.

[PATRICK MOORE] The loss of life that is caused by coal mining and breathing fumes from coal-fired power plants is hundreds of times larger than any damage that has been caused by nuclear power.

[ARJUN MAKHIJANI] You don't want to build new coal-fired power plants.

[SUITERS] Energy researcher Arjun Makhijani has his own plan, heavy on renewable sources, like the hydroelectric plant there behind us in Vermont.

[ARJUN MAKHIJANI, INSTITUTE FOR ENERGY AND ENVIRONMENTAL RESEARCH] In about 40 years, we could phase out all the energy sources we don't like, including nuclear, coal, and so on.

[SUITERS] When you say, "we don't like," you mean the most controversial?

[MAKHIJANI] Yes.

[SUITERS] So then, where do we turn? Maybe a mix -- something renewable and something with lower carbon emissions than coal.

[MAKHIJANI] The fuel you have to help you bridge are natural gas and hydro.

[SUITERS] Only if we are building a bridge away from nuclear.

[MIKE McKENNA, MWR STRATEGIES] Overall, I think safety in the United States hasn't changed much in the last month, but perceptions may have.

[SUITERS] Political strategist Mike McKenna represents utilities, including some that rely on nuclear power. He says nuclear will be an essential element of any major energy legislation.

[McKENNA] You need to make promises to nuclear, to coal, to natural gas, to wind, and to solar, for them to all kind of join hands and move together.

[JAMES MOORE] What we need to do for our future is look to our future and actually start building the stuff that our next generation wants to be reliant on.

[SUITERS] And getting rid of the stuff left behind -- nuclear waste, that has no permanent storage site in the U.S.

[MAKHIJANI] This spent-fuel pool over here down the street has more spent fuel, by my calculation, than all of the four spent fuels in Fukushima put together.

[SUITERS] And Vermont Yankee stores its spent fuel in the same way, in the same design, as Japan's disastrous Fukushima plant.

[PATRICK MOORE] We should really remember that 95% of the energy is still in that used fuel.

[SUITERS] Fuel that could be recycled and reused may be the future of U.S. nuclear energy. But the present is being decided in Vermont, based largely on the past.

[SMITH] All of the modifications through the years, going back to the 1970s, that were recommended or suggested by G.E. or mandated by the Nuclear Regulatory Commission, this plant implemented.

[JAMES MOORE] We're talking tens to hundreds of millions of dollars, improvements that need to be made to that aging facility, if they are going to try and run it for 20 more years.

[SUITERS] Vermont Senator Bernie Sanders is now asking President Obama for a moratorium on all license renewals for U.S. nuclear plants, but, Thalia, the political strategist you saw, Mike McKenna, says that's not going to happen. The electricity the U.S. gets from nuclear generation is simply too important to take offline anytime soon.

[ASSURAS] Too much, I guess. Tyler Suiters, thanks very much.

And you at home are weighing in on the nuclear debate. The Pew Research Center conducted a poll between March 17th and the 20th, showing that support nationwide for expanding America's use of nukes has dropped. Just six months ago, Americans were evenly split, 47/47, on using more nuclear power. Now, according to the new survey, 52% of Americans are against nuclear expansion. Support dipped to 39%. Public sentiment on nuclear energy has, in fact, fluctuated in recent years, and according to Pew, the greatest support for nukes, 52%, was registered early last year.