Christopher Joyce

America's nuclear reactors need new safeguards to ensure that the kind of accident that destroyed reactors in Japan last March doesn't happen here. That's the conclusion from a 90-day study of the accident undertaken by experts at the U.S. Nuclear Regulatory Commission.

The Fukushima accident in Japan damaged or destroyed four reactors and spread radiation for miles around the plant and it shook confidence in nuclear power around the world. Shortly afterwards, a task force of engineers at the NRC got their marching orders: figure out how to keep this from happening in the U.S.

Almost 60 years ago, engineers in Idaho switched on the world's first nuclear power plant. It was only able to illuminate four light bulbs. The reactor vessel in Idaho stood about eight feet high, and eventually it made enough electricity to power a building.

A nuclear plant today can produce 10,000 times as much electricity. But for the last 20 years, new nuclear plants have been too expensive to build. Now engineers are trying to revive the industry by thinking small again.

We humans can brag about our large brain, but in fact most mammals — from aardvarks to zebras — have big brains for their body size. For years, scientists have wondered what evolutionary forces pumped up the mammal brain so much, and now they may have an answer.

Mammals needed a better sense of smell.

The March 11 earthquake just off the coast of Japan surprised many experts. Geologists say they didn't expect that big a quake in that spot.

But they do fear that more big quakes may be in the offing in or near Japan. Scientists can't tell when, but they're trying to narrow down where.

The answers lie amidst the huge plates that make up the Earth's crust. Think of them as like floating ice sheets on a lake.

Engineers probing the ruined nuclear reactors at Japan's Fukushima Dai-ichi plant are finding yet more damage. Not only did fuel melt in three reactors, they've just discovered a hole in one reactor vessel. And radioactive water continues to leak at the site. That mess in Fukushima has led several governments to reassess nuclear power.

Japan was planning 14 new reactors. Germany, famously anti-nuclear, had approved several new plants. Utilities in the U.S. had plans for new reactors as well.

Now?

The accident at the Chernobyl nuclear power plant 25 years ago not only changed the lives of people in Ukraine; it also put a radioactive stain on the continent. And it showed just how far-reaching the ramifications of a serious nuclear accident could be.

Although images of dead birds and blackened marshes in the Gulf of Mexico are gone, many scientists say it's too early to declare a recovery. They suspect there could be hidden damage to the Gulf's marine life and marshes. And some of these scientists say research on the effects of the spill has been delayed or kept secret.

Velociraptors, those clever carnivores that hunted in packs in the Jurassic Park films, may actually have been night hunters.

That's the conclusion of scientists who have studied the bones of dinosaurs, reptiles and early flying creatures that lived tens of millions of years ago. In particular, they examined the eye sockets, which the scientists say reveal a great deal about what kind of vision those extinct animals had.

The nuclear accident in Japan has rekindled debate about what to do with used reactor fuel.

The Japanese power plant housed tons of highly radioactive used fuel in pools filled with water. Some of that water either leaked out or boiled away during the accident, putting that fuel at risk of burning and releasing radioactive material. With similar fuel pools at more than 60 reactor sites in the U.S., there's renewed interest in their safety.