By Evan Halper, Tribune Washington Bureau (TNS)

MOUNTAIN VIEW, Calif. — The state that spawned a generation of activists committed to shutting down nuclear reactors and crippling the industry has lately become a hotbed of advocacy and financial support for fighting global warming with, of all things, nuclear power.

Encouraged by the Obama administration, notable California innovators and financiers are looking to reinvent the industry in the mold of wind and solar power. They are betting on prototype technologies that seek to replace the hulking plants of today with smaller, nimbler units. Environmentally minded nuclear engineers argue that they can be designed so safely that they might be “huggable.” They talk of power plants that consume nuclear waste instead of creating it.

State leaders aren’t necessarily rushing to embrace the vision in a place where all but one nuclear plant have been mothballed and where old-guard nuclear safety advocates warn that so-called advanced nuclear technologies are an attempt to put shiny earrings on the same old pig.

But the investors and nuclear scientists opening startup labs in the office parks of California’s technology hubs and within the research centers of universities see a more influential ally in the White House.

Nuclear power is at the nub of the Obama administration’s “all of the above” strategy for reinventing the energy industry in an era of climate change, and its faith in the fraught power source has captured the imagination of some notable and deep-pocketed West Coast thinkers.

Investors, including Microsoft founder Bill Gates and PayPal co-founder Peter Thiel, have poured about $2 billion into a few dozen small outfits, many of which are concentrated in the West. The entrepreneurs behind them are racing to design nuclear power facilities engineered to seem no more imposing than a neighborhood arts center.

“This is the place to be,” said Jacob DeWitte, chief executive of UPower, a startup that recently migrated here from Cambridge, Mass., in its quest to create modular nuclear plants with reactors small enough to fit inside a shipping container and sturdier than “a brick outhouse.”

“In other places you would tell people you’ve got a nuclear startup and they look at you like you are kind of nuts,” he said. “But here in Silicon Valley it is like, ‘That’s super cool. Can I help?’ There’s that ethos here.”

DeWitte, 30, talks in terms that make some veterans of the decades long struggle over nuclear power chafe, promising his firm will build units that could safely run on existing stockpiles of nuclear waste, all while being “meltdown-proof” and not using any material that terrorists could steal to turn into a weapon.

That may all be possible someday, say the nuclear experts at the Union of Concerned Scientists, but that day is probably several decades and many tens of billions of dollars away. The sudden excitement around nuclear makes them nervous. They say they have seen this before.

“The people who deny or downplay the risks involved are doing a disservice to the future of nuclear power that leads to complacency, and complacency leads to Fukushima,” said Edwin Lyman, a senior scientist at the organization. “This is very complex. It is hard. It costs a lot. It is slow, especially to develop advanced systems. … It seems nuclear will at most be a minor contribution over the next few decades to dealing with the climate crisis.”

That’s not the view inside the stylish, airy San Francisco offices of Thiel’s Founders Fund, where he and other venture capitalists, perhaps inspired by the views from the giant windows overlooking Presidio Park, make big bets on big ideas. Thiel made about $1 billion with an early $500,000 investment in Facebook. He got in on the ground floor with Yelp. He and his partners at PayPal, including Elon Musk, grew the online payment service from nothing to a firm that eBay paid $1.5 billion to acquire.

And lately Founders Fund is excited about zero-emission nuclear power as a solution to climate change. It has infused $3 million into Transatomic, a startup in Cambridge launched by two graduates from MIT’s nuclear engineering program who have been pitching their vision in small networking meetings and, of course, TED Talks.

“I became a nuclear engineer because I am an environmentalist,” said Leslie Dewan, the 31-year-old co-founder of Transatomic. “This is what the world needs. The world needs a cheap source of carbon-free power that is even lower cost than coal if we want to avoid the devastation caused by fossil fuels.”

Her faith in nuclear energy is underscored by the fact that she launched her company only a week after the Fukushima nuclear plant disaster in Japan in 2011. The particular day also happened to be the 25th anniversary of the 1986 Chernobyl nuclear power plant disaster in Ukraine.

The faith is shared by Founders Fund partner Scott Nolan, who is among the few equipped to judge the mind-bending Transatomic blueprints on their merits. Nolan is a rocket scientist. Earlier in his career, he built propulsion systems at a firm that is perhaps even more audacious than Transatomic: Musk’s space exploration company, SpaceX.

“We believe they have the right technology, that it is going to eliminate a lot of the concerns that have existed around nuclear,” Nolan said. “We think it can work.”

He talks about the anxieties around nuclear power: the potential for radioactive release at a plant, the possibility terrorists will steal material to build a dirty bomb, the dangerous waste that won’t decompose for thousands of years, the immense costs.

Then he dissects each concern, explaining why Transatomic’s technology makes the issue obsolete. He talks about a plant that would run on existing nuclear waste and be “classified as walk-away safe. There is no way for it to go unstable.”

The Sierra Club says it has all the makings of a snake-oil sale.

“There is always such a rosy picture coming from the industry of what it can deliver with these technologies, yet it has such a terrible history with over-promising and under-delivering,” said John Coequyt, the Sierra Club’s director of international climate programs. The organization would prefer the Obama administration abandon the extremely costly pursuit of advanced nuclear power in favor of greater investment in renewable energy such as solar and wind power.

©2015 Tribune Co. Distributed by Tribune Content Agency, LLC.

Photo: Pelicans fly in formation over the San Onofre Generating Station on Tuesday, March 25, 2014 in San Clemente, Calif. (Allen J. Schaben/Los Angeles Times/TNS)