In some of my fondest childhood memories, my heavily bundled siblings and I followed our mom into the back yard after each new snowfall.

Mom would brush away the top layer on the ground and collect a mound of snow in her mixing bowl. We’d run behind to the kitchen, where she’d add just the right amount of cream and sugar to make a treat of snow ice cream.

It was a delightful 1950s winter dessert and more fun than chasing an ice cream truck down a sultry, summer St. Louis street. But sadly the fun childhood experience ended in the early 1960s. I never repeated it for my children.

Mom and Dad explained that radioactive fallout from nuclear bomb tests had made the snow too dangerous to consume. We were in the Cold War. It was always the ugly, three-headed monster under the bed and in the dark closets of baby boomers’ youth.

The Hydra’s heads included the Soviet Union, China and our own United States. They had us practicing “duck and cover” drills in school, paying attention to air-raid sirens and knowing the public signs pointing to bomb shelters for when “the big one” might someday be launched.

The real danger, it turns out, wasn’t so much from some renegade superpower as from Mother Nature humbling humanity for daring to harness nuclear energy to power our wasteful way of life. An earthquake and tsunami that hit Japan in March crippled six reactors at the Fukushima Daiichi nuclear power plant, disrupting the flow of vitally needed water to cool the reactor cores.

Explosions of built up hydrogen have resulted, and dangerous levels of radiation have invaded the environment. Tokyo’s tap water briefly exceeded safety standards for infants. That’s far worse than the radiation warnings for the snow of my youth.

Radiation from the disaster also has seeped into raw milk, seawater and some vegetables including turnips, spinach, broccoli and cauliflower in Japan. Radiation from Japan’s nuclear plants has been detected in Las Vegas and Kansas but only in trace amounts.

Last week, schools were closed in South Korea with teachers and parents panicking over fears that rain could carry radiation from Japan.

Workers have pumped more than 3 million gallons of contaminated water from the damaged nuclear plant into the Pacific Ocean, freeing storage space for even more dangerously radioactive water. The news grows more grave with scientists describing the situation as “unpredictable” and worrying about a “breach of containment.”

One explained it’s worse than the March 1979 disaster at Three Mile Island where 90 percent of the core suffered damage, but the steel vessel surrounding the core was not breached.

If radiation becomes so extreme that workers have to abandon spraying cooling water on the reactors with fire hoses then three simultaneous meltdowns could occur with steam or hydrogen gas explosions completely rupturing the containment. One expert warned of a “nightmare beyond Chernobyl.”

In 1977 I covered protests of the Wolf Creek power plant in Kansas. It turns out those folks may have been right.

When the weather and other environmental conditions remain stable, nuclear power seems OK if people ignore the mounting waste, construction flaws, accidents and more intensive oversight recently recommended for Wolf Creek because of ongoing problems. A global catastrophe like Japan’s is all it should take to keep humanity from continuing to arrogantly think it’s possible to safely harness such a terrible force for electricity.

Protests now in Japan and Germany against nuclear power are justified. The accidents that we have witnessed so far have humbled humanity into realizing how limited our abilities are to quell such a terrible force that could eventually do irreparable harm to our planet.

Throw sea water on it. No, too corrosive. Use fresh water. Not even 500,000 gallons is enough. It’s all going back in the environment, affecting us.

Let’s hope President Barack Obama and operatives in the GOP — or gas, oil and plutonium party — pay attention to the disaster. What’s going on in Japan may seem a world away, but like the snow of my youth, it will land highly toxic in our back yard.