A new breed of nuclear reactors some consider much safer than the current breed and free from the possibility of a meltdown has been developed. However, although they have been built elsewhere, they probably will not become part of the United States nuclear power industry.

The new breed, known as "inherently safe," is not being built in America but has been successfully in use in West Germany for the past 20 years, Jim Kastings, associate professor of geoscience and meteorology, said.

The nuclear industry has invested large sums of money into the current breed of reactors and is reluctant to invest more money for the development of the inherently safe reactors, believing the current breed is adequately safe.

Instead of building the inherently safe reactors in America, the nuclear industry plans to further develop the current breed of reactors, known as "Light Water Reactors" or LWRs, said Forrest J. Remick, chairman of the Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards, University associate vice president for research and professor of nuclear engineering.

"The reactors that people are calling inherently safe are inherently safe on paper," Remick said. "There has been a tremendous investment in LWRs and we have a lot of years of experience. Inherently safe reactors have promising attributes, but I know of no utility that will build one."

Peter Gould, professor of geography and author of a book on the 1986 Chernobyl nuclear accident, disagreed with Remick, saying, "I think there are inherently safe reactors. There has been a pilot project running in Germany. If we had the will, we could build them right now."

New reactor features

Several kinds of inherently safe reactors have been developed. All use new types of radioactive fuel which have a higher melting points than the fuel used in common LWRs. Because of this new fuel, the inherently safe reactors can heat to higher temperatures before having a meltdown, Kastings said.

Beside using a new fuel, there is also a different type of cooling system in inherently safe reactors than in the LWRs. The most advanced type of inherently safe reactor, the gas-cooled, uses helium as a coolant rather than the conventional coolant, water. These reactors operate on the physical principle of convection and automatically shutdown when the fuel reaches a certain temperature, guarding against meltdown. Because the reactor the reactor is free from meltdown, it has been termed "inherently safe," Kastings said.

"It's much safer and will shut itself down. Unless the earth opens up and swallows the coolant, you're not going to melt them down," Kastings said.

Controversy

Edward H. Klevans, head of the University department of nuclear engineering, said, "I think the term 'inherently safe' is extremely controversial. I would not want to go on the witness stand and say radiation could not be leaked into the environment."

Lawrence M. Lidsky, who Klevans feels is the foremost authority in the inherently safe reactor field and is a professor of nuclear engineering at the Massachusetts Institute of Technology, believes inherently safe reactors are so safe that the containment building, the protective wall of steel and concrete around the reactor, is unnecessary.

"In principle, an inherently safe reactor can survive the worst case test without a containment building. The public may demand one for psychological reasons and because this is a democracy, you have to do what the public wants."

General Atomics, one of the leading U.S. producers of nuclear reactors, has submitted a design to the NRC for an inherently safe reactor that does not have a containment building, Klevans said.

"General Atomics believes it cannot have a meltdown and therefore does not want to build a containment building due to the high cost," Klevans said. "It's not at all clear the NRC will approve the design."

Judith Johnsrud, co-director of the Environmental Coalition on Nuclear Power, is skeptical about claims of safety in reactors and said, "The term 'inherently safe' may be applied to the construction, but the chances of any facility not suffering serious accidents is very small. These reactors are designed by humans and humans make errors."

While many dislike the idea of building inherently safe reactors, Lidsky said if they are not built, the nuclear industry will eventually die.

"If there is a future for the nuclear industry, it is with inherently safe reactors. They are smaller, less expensive, more reliable and potentially more acceptable to the public," Lidsky said.

Inherently safe reactors are one-half to one-third the cost of LWRs and are "substantially cheaper" than coal production, Lidsky said. He expects one to be built in the next six to seven years.

"The last thing people in the current industry want is to look at the new technology. Anytime you bring up inherently safe reactors, they walk away. They've already sunk a lot of money in the LWRs," he said.

According to Remick and Klevans, Lidsky's view of the future of the nuclear industry is wrong. The LWRs, which the NRC considers "very safe," will continue to be the source of nuclear power in the U.S., they said.

Remick said, "In the 1950s when I just starting, everyone designed a reactor that was safer and better. It's a long and difficult task. It's great to talk about reactors on paper that are safer and more reliable, but this is completely new technology. I think we will see evolutionary changes in the LWRs."

Environmental risk

Kastings, looking at the nuclear industry from an environmental standpoint, feels safer nuclear reactors must be built to make them more acceptable to the public so they may become the major source of power in America. Nuclear power is the only viable option that does not contribute to the greenhouse effect, he said.

While increasing the use of nuclear power would prevent further damage to the atmosphere, it would result in an increase in radioactive waste. The government is now in the process of finding one site for all the high-level waste produced in the country. High-level waste consists of remnants from the actual radioactive fuel, Klevans said.

Kastings said, "We will have to set aside sizable areas to be used to hold the waste. This is the lesser of two evils - we either ruin the whole earth with the greenhouse effect or have localized areas that become uninhabitable."