Marlton executive is bullish on nuclear waste

Engineer and CEO Krishna "Kris" Singh has a surprisingly sunny view of nuclear waste. Sure, it could kill a person from a few feet away, and stay radioactive for a million years, he said, but someday we'll learn to harness the energy in it.

Oil was worth little before someone invented the engine, he added. And platinum was just a bothersome by-product of silver mining to the Spanish colonists. "Every material has its time," he said.

Singh, 61, has made his career out of such optimism. His Marlton company, Holtec, has devised several unique systems for one of the hardest jobs on the planet - storing spent nuclear fuel - used to some extent at 80 of the country's 104 plants.

He is now working toward a new generation of storage materials based on nanotechnology - the study and manipulation of materials at invisibly small scales. And he has just donated $20 million to the University of Pennsylvania to create one of the country's biggest centers for this fast-growing field.

Nuclear power is one of the many industries that Singh predicts will be transformed by nanotechnology. He's looking to the field to help design novel material to better protect people from the 60,000-some-odd metric tons of spent fuel stored in the United States - at least until it becomes the new platinum.

"I'm a materials-metals guy," Singh said. "I've always wished we had better materials. Nanotechnology-based materials are going to be like the plastics of tomorrow - changing the way we make and build everything."

Singh came to Philadelphia from India in 1968, and finished his Ph.D. at Penn. His role in nuclear power began when a policy change nearly shut the country's plants.

Until the late 1970s, the long, thin uranium rods that fueled nuclear power plants were partly recycled. The various components were separated out in what was called reprocessing. That left them with some waste as well as usable uranium and weapons-grade plutonium.

But by the mid-1970s, the United States already had enough plutonium bombs to destroy the world 100 times over. The Ford administration prohibited reprocessing of nuclear fuel to help stem the worldwide proliferation of nuclear weapons, Singh said.

But plants lacked the capacity to store used rods if they weren't reprocessed. "It could have forced all the nuclear power to shut down," Singh said. "Without reprocessing the fuel, the plants would get constipated."

With current technology, nuclear power is a wasteful process - the fuel rods becoming "spent" within a few years even though they are still highly radioactive.

When they go into the reactor, the fuel rods are made of uranium; up to 5 percent is the fissionable form known as U235. Put in close proximity to one another, a chain reaction starts in which the nuclei of uranium atoms are split into smaller pieces, releasing energy as well as fast-moving particles called neutrons, which hit and break up more uranium nuclei.

After some three to six years in the reactor, more than half of the U235 atoms have been split, creating daughter products, many of them exotic radioactive isotopes with half-lives from seconds to thousands of years.

Some of those reaction products are called "poisons" because they slow down the fission process. Once infused with enough poison, the rods are considered spent, though they are still capable of more energy-producing fission.

Traditionally, plants could keep a few spent rods in swimming-pool-sized tanks. The rods had to be kept far apart because they could still shoot neutrons at one another, and trigger more fission.

In the early 1980s, Singh devised a way to fit more rods into the pools safely. The trick was to separate the rods with neutron-blocking shielding - aluminum spiked with boron carbide.

Those shielding "racks" allowed plants like Limerick and Three Mile Island to store the rods much closer, he said, but they also had to be designed to survive earthquakes, plane crashes, and other disasters.

Singh's designs led to between 17 and 20 patents - he isn't sure of the exact number. The company also makes casks for what is called dry storage - where the rods were dried and sealed inside metal canisters.

While there are three competitors out there, Singh's storage technology is used to some extent in all the nuclear power plants in Pennsylvania and most plants across the country.

His company recently contracted with the Ukrainian plant at Chernobyl to put its reactor into dry storage.

The privately held business, which employs more than 500 people, could continue to grow. Trade groups are declaring a nuclear renaissance prompted by concerns over foreign oil dependence and greenhouse-gas emissions. And on-site storage will have to keep growing if the United States continues to reject plans to consolidate the nation's nuclear waste at the Yucca Mountain site in Nevada.

Some scientists see a growing danger. "If you do it right, then it can be made pretty safe for an interim period," said physicist Edwin Lyman of the Union of Concerned Scientists. "But they're still not doing it right."

For him, the right way is dry storage, while the wrong way is to use shielding racks to "cram more fuel rods into the pools." The more rods in the pool, the greater the danger if it turns out that the racks don't hold up to an earthquake or some act of terrorism, he said.

Still, he said, "reprocessing" and then recycling would be much worse because it would separate out weapons-grade plutonium.

"You're basically doing the terrorists' job for them," he said. In England, they still reprocess their fuel and are now stuck with hundreds of metric tons of unwanted plutonium.

Singh said he had occasionally had to hire security to protect his employees from protesters. One group descended on company headquarters during the 2000 Republican convention, carrying a fake cask with the sign "Mobile Chernobyl."

Singh says the advantages of nuclear power outweigh the dangers - especially in light of problems with fossil fuels. And nuclear technology will advance. That's why he is devoting part of his company to nanotechnology.

For example, he said, it is looking at the way tiny "nanoparticles" can improve the process of powder metallurgy. Metals made that way look solid, but between grains are invisibly small spaces. Being many times smaller, nanoparticles can fill in those cracks and crevices like mortar between bricks.

It's not just that scientists are working with such small particles, said Penn engineering dean Eduardo Glandt. It's that they can manipulate matter on an atomic scale. "We can play like an Erector Set with atoms."

Nanotechnology is what Glandt calls the next great technological wave - one of three strands of innovation along with biotechnology and information technology.

Singh's $20 million donation will go toward a new nanotechnology building at 33d and Walnut Streets. Planned for completion in 2012, the $80 million Singh Center could make Philadelphia a leader in nanotechnology, Glandt said.

One of Penn's strengths is in combining nanotechnology with biology - looking at new ways to diagnose disease and deliver drugs, he said. And one dream is an imaging and diagnostic device that a patient could swallow, transmitting critical images and data as it travels through the body.

But nanotechnology is a fussy science, requiring dust-free, vibration-free clean rooms. It's not impossible to do that in West Philadelphia, Glandt said.

Singh said he had no plans to slow down his own brainstorming. A few years ago, he devised a system for storing waste underground. The idea is about to be licensed by the Nuclear Regulatory Commission, he said. But he often doesn't know whether such an idea will find buyers.

"My job is to make a fair guess as to what the world needs," he said. "Then I go to work and bring it to them."