Atomic Insights

Atomic energy technology, politics, and perceptions from a nuclear energy insider who served as a US nuclear submarine engineer officer

Minimize Waste: Focus on Recycling

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One of the most successful ways to conserve valuable raw materials is to pay careful attention to manufacturing and use processes so that less of the material is wasted. There is ample opportunity for process type improvements in the nuclear power industry, even though many improvements have already been made.

There are also institutional hurdles that must be overcome in order to make full use of available technology. These barriers are similar to those faced in many other industries where efforts to reduce environmental damage are being advocated.

Before discussing this issue, there are a few bits of terminology that need to be understood. The term “burn-up” refers to the amount of energy produced by a given quantity of nuclear fuel. The normal units for burn-up are MegaWatt-days/tonne of heavy metal.

A tonne (1000 kg) of uranium, thorium or plutonium, the heavy metals useful in reactor fuels, could release almost one million megawatt days of heat energy if completely fissioned. Unfortunately, our current state of the art is far from complete fission.

Then and Now

Nuclear scientists and engineers have made some progress over the years. The earliest reactors normally achieved burn-ups of about 5,000 to 7,000 MWdays/tonne (about .5 to .7 percent of the ultimate potential.) Standard light water reactors using low enriched uranium now achieve routine burn-ups of 35,000 to 45,000 MWdays/tonne (3.5 to 4.5 percent of the potential).

Some well tested advanced reactors have achieved levels of 150,000 to 160,000 MWdays/tonne (15 to 16% of the potential). Commercial reactors using the designs from these programs would produce about a quarter of the waste of current reactors even without any recycling program.

United States naval reactors, optimized for high endurance operation, achieve routine burn-ups of 500,000 to 600,000 MWdays/tonne (50 to 60 percent of the potential). Since these reactors use valuable highly enriched uranium, the remaining material was routinely recycled for many years. The downsizing of the nuclear navy and the reduction in demand for highly enriched uranium led to the 1992 decision to close down the reprocessing facility in Idaho. The waste is now simply stored.

Efficiency Equals Design

The amount of burn-up that can be achieved is a function of the material properties of the fuel, the nuclear properties of other materials in the reactor including the coolant, the reactor control system, the fuel loading scheme and the enrichment of the fuel.

It might be useful to think of a fire analogy in trying to understand why there is such a large variation in the percentage of material that can be effectively “burned” in various kinds of reactors. Depending on how the fire is built and operated, there will be varying amounts of wood left over.

In the early days, reactors were really designed like charcoal production fires, the goal was to convert uranium into a product (plutonium), not to produce the maximum amount of energy. Modern light water reactors are like large bonfires trying to burn very wet wood with a small amount of kindling. The kindling burns and then the fire goes out leaving most of the wood intact. Naval reactors are like small fires that are carefully tended to produce the maximum heat from a limited quantity of high quality material.

The basic methods available to improve fuel use efficiency focus on improving the percentage of neutrons that are absorbed in fuel over other materials in the core, improving the resistance of the fuel structural materials to irradiation damage and increasing the amount of potential fuel in a given volume.

As might be expected from an optimization problem with so many variables, achieving maximum energy release from nuclear fuels is a complex endeavor. It involves weighing the cost of changes versus the benefits obtained.

The effort has the potential for nuclear utility cost reductions, however, because it not only reduces waste and associated storage difficulties, but it reduces the time that the reactor is shut down for refueling. It also reduces the cost of fabricating, transporting and handling the fuel for a given reactor. Several of the advanced reactor programs have projected major savings from increases in nuclear fuel usage.

Resisting Change

Nuclear fuel suppliers, however, have been slow to develop advanced fuel cycles that can reduce fuel use and waste production. We must always remember that one person’s cost is another person’s revenue. The most economical choices for energy consumers are not always the most economical choices for nuclear fuel suppliers.

Nuclear fuel companies have resisted improvements in fuel life in a manner reminiscent of the resistance offered by the biased ply tire industry to the introduction of long life radial tires. If fuel suppliers provide fuel that can last two to four times as long as their current product, they will sell less fuel to their existing customers.

The Nuclear Regulatory Commission helps keep the established fuel suppliers in business through its licensing process. It takes years to gain approval to alter the licensed fuel cycle for a given reactor plant. The Commission calls it a “conservative” approach, but the result is to allow companies that produce existing products to maintain their markets for many years after competitive improvements have been demonstrated in laboratories.

John W. Simpson, a former high level executive with Westinghouse, the world’s largest supplier of light water reactor fuel, has recently written a book titled Nuclear Power from Underseas to Outer Space that gives some insight into his former company’s nuclear fuel business strategy. Simpson stated, “As film is to the camera manufacturer, nuclear fuel is to the reactor builder. It’s a business that has the potential of continuing sales for the life of the plant.”

Unlike tire consumers, utilities are somewhat constrained in their ability to shop for better fuel. As Simpson wrote, “The customer utility was free, of course, to buy future fuel from our competitors, but the utilities thought they might experience difficulties buying future fuel from anyone but the plant vendor for technical reasons . . . We also wanted to sell as many fuel reloads with the initial plant order as possible . . . This fuel business has continued to be a mainstay of our nuclear business, along with reactor service, long after plant orders were a distant memory.”

One of the services that Westinghouse and other fuel supply companies have traditionally provided to nuclear utilities is support during refueling outages. This is a large business involving thousands of people and millions of dollars worth of sales to the company. Short-lived fuel has been a profitable product for many years.

The strategy of maintaining fuel sales high by restricting performance, however, is doomed to failure in a competitive market. Have you purchased any biased ply tires recently?

Opposition to Reprocessing Are the Reports Always True?

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One of the reasons this letter focuses on the issue of recycling and waste minimization is that there has been a recent full court press in the opinion sections of major newspapers and in Congressional hearing rooms to stiffen the U. S. government’s already extreme policy limiting the use of plutonium in energy generating plants.

In case you have missed the debate, here are the statements that are being offered by a small but influential group of people opposed to the commercial use of plutonium:

  • Source: In literature sent out by the Nuclear Control Institute (NCI), a Washington D.C. based special interest group, the statement is offered that MOX fuel costs four to eight times as much as virgin uranium fuels.
  • Date: June 8, 1994
    Source: In an article from the op-ed section of the Wall Street Journal    , Paul Leventhal of the NCI called for the Clinton administration to follow a policy of disposing of retired warheads as waste instead of converting it for fuel for reactors.
  • Date: April 4, 1994
    Source: In an article from the op-ed section of the Wall Street Journal    , Albert Wohlstetter, the man who headed the 1975 study leading to the U.S. abandonment of nuclear fuel recycle programs and Gregory Jones, a defense consultant, stated “It has long been plain that plutonium for electric power has a largely negative value. The civilian benefits are a myth.”
  • Date: January 25, 1995
    Source: In an opinion piece in the New York Times op-ed page    , Paul Leventhal and Daniel Horner, the Deputy director of the Nuclear Control Institute, warned of a growing trade in nuclear fuel materials.
  • Date: June 6, 1994
    Source: In testimony before the Joint Economic Committee of the the U.S. Congress    , Paul Leventhal concluded a 16 page report by stating, “I hope the Committee will consider issuing a report on the unfavorable economics and lack of need for plutonium. The plutonium industry represents a gross distortion of the free market. It is an industry that insists on churning out a valueless product for which there is no market.”
  • Date: November 22, 1994
    Source: In an article in the Disarmament Times    , Mr. Leventhal stated, “The benefits of atoms for peace are also greater if plutonium is not separated from spent fuel and not ‘recycled’ as power-reactor fuel since the ‘once-through’ fuel cycle (in which plutonium is disposed of as waste) is cheaper, safer, more safeguardable, and less controversial than reprocessing.”
  • Source: In a well timed declassification, the Department of Energy of the United States released information regarding the test of a bomb made with “reactor grade” plutonium in 1962. This report has been mentioned in almost all of the above sources. Interestingly enough, the Secretary of Energy has received specific praise by the NCI for her stand in opposing the use of plutonium recycle.

Logical, reasonable people should find ample reason to be uncomfortable with the above statements, if they have any inkling of the potential energy stored in plutonium. Even without that knowledge, it seems strange for an organization to be advocating the disposal of material that highly competent technicians say is useful.

One might also question the group’s resistance to a plan that removes plutonium, with its 24,000 year half-life from irradiated nuclear fuels. Most of the isotopes in the waste stream from reprocessing plants have less than a 30 year half-life. The material decays to an activity less than the original uranium ore in less than 300 years.

The Whole Truth

Some of the statements being made are false. For example, according to the OECD’s 1992 Nuclear Power Economics and Technology: An Overview, MOX fuel costs between 0.35 and 0.45 cents per kilowatt hour produced. That is essentially the same price as virgin uranium fuel using today’s price of natural uranium.

The DOE’s press releases about the bomb made from “reactor grade” plutonium are, at best, confusing. The material for the bomb came from a British dual purpose reactor type (weapons material and power production) known as MAGNOX. The fuel had a very low burn-up and a low concentration of plutonium isotopes heavier than Pu-239. Most weapons designers agree that it would be extremely difficult to make a bomb with fuel that has the isotopic concentration of today’s light water reactor fuel.

It would be easy to dismiss the influence of a pressure group with as thin a stable of writers as the NCI, but they have been able to make their arguments heard by influential decision makers.

Partly as a result of their pressure, the Integral Fast Reactor (IFR), a project in the final stages of demonstrating a closed fuel cycle, was cancelled by the Clinton Administration.

According to Dr. Terry Lash, the Director of the Office of Nuclear Energy for the Department of Energy, “the program was found to be inconsistent with U. S. nonproliferation policies.” The IFR was designed specifically to keep all nuclear materials within the security boundaries of the plant with no possibility of diversion. There is no way the project could have contributed to the proliferation of nuclear weapons.

There is nothing new in the arguments offered by the Nuclear Control Institute. The Carter Administration’s 1977 policy towards nuclear fuel recycling was influenced by a report Ford Foundation report titled, “Nuclear Power Issues and Choices” written by a group of professors of political science and economics. The report, published more than 20 years ago, focused on the proliferation risks that would be presented by a world expansion of the “plutonium economy,” by recycling plutonium in light water reactors or using it in fast breeders.

The group is using recycled arguments that are at least 20 years old, ignoring years worth of research and development, yet they seem to be winning the debate. Incredible!