Kevan Weaver, Ph.D, Director of Technology Integration
TerraPower’s traveling wave reactor (TWR) technology will help with a perceived problem highlighted by critics of nuclear power: nuclear waste.
Only one source of carbon-free electricity is economic, reliable 24/7, and proven to work on a large scale: nuclear power. Nuclear power generation is criticized by some in the United States because current reactors produce tons of radioactive waste without a permanent, dedicated storage space in this country. The most significant high-level waste from a nuclear reactor is the used nuclear fuel left after it has spent more than four years in the reactor generating heat for electricity. The cost of disposing of nuclear waste from commercial reactors in the United States has been estimated at $92 billion. Each reactor generates waste that, in 2014, was estimated to cost $300 million to manage.
However, the volume of the spent nuclear fuel produced by a TWR will be about 80 percent less than that produced by the commercial “light water” reactors in use in the United States today. This is because TerraPower’s TWR burns not only the initial enriched material, but also converts and burns much of the natural or depleted uranium in the fuel without reprocessing, compared with the reactors currently in use that burn just enriched material. In fact, depleted uranium, previously considered a waste by-product of the uranium enrichment process, is the sustaining fuel source for the TWR.
Use of depleted uranium will also reduce fuel costs, where fuel costs currently make up 30 percent of the cost of producing power with a nuclear plant. One-third of those fuel costs are due to enrichment, which is necessary for the current crop of light water reactors in the United States. For a typical U.S. reactor, the approximate cost of fuel reloads is about $40 million, based on an 18-month refueling cycle, or more than $13 million for enrichment alone. But this is not the case for TerraPower’s TWR, which does not use enriched uranium except at startup, resulting in a lifetime fuel savings of hundreds of millions of dollars.
Moreover, a TWR can run for at least a decade without refueling, with only depleted uranium needed for the reloads. Such a dramatic increase in fuel efficiency means that a larger portion of global uranium resources can remain underground. Mining has become a controversial activity in the conversation about climate change. TerraPower’s reactor obviates the need to mine for new uranium resources to sustain the operation of TWRs for centuries after their startup period.
Given all this, from an environmentalist’s point of view and from a business manager’s point of view, TerraPower’s TWR provides an improved waste option solution – not only to problems of the volumes needed for waste disposal but also to the problem of operating costs as related to fuel costs.