The US Department of Energy has a stockpile of approximately one ton of Uranium 233 that was produced as part of several experimental programs including the Molten Salt Reactor Experiment and the Light Water Breeder Reactor. According to a March 3, 1997 decision by the Defense Nuclear Facilities Safety Board, the stockpile is held in a number of different physical and chemical forms and is located in secure storage facilities at several DOE sites with the majority of the inventory held at either the Oak Ridge National Laboratory or the Idaho National Laboratory.
The current plan for this material is to blend it with about 15-20 tons of depleted uranium. The design effort for the facility to be used for this blending process has been running into some cost and schedule issues; the most recent cost estimate is $477 million with an expected start date of the blending at the end of 2012 with the project completing near the end of 2015.
This plan seems like a waste of both money and a potentially valuable feedstock. The reason that the U-233 exists is that a number of forward looking scientists and engineers recognized that thorium, a heavy metal that is 3-4 times as abundant as uranium in the Earth’s crust, is a potentially valuable nuclear fuel. It is not fissile in its natural form, but it can be converted into U-233, which is fissile. A thermal spectrum reactor using U-233 as the fissile material and Th-232 as the fertile material can breed; that has been proven with much greater than laboratory scale experiments.
The existence of an inventory of U-233 gives the concept of a Liquid Fluoride Thorium Reactor (LFTR) a head start. Destroying that material now would raise the barrier to getting that concept off the ground.
The process set into motion by a 1997 decision should not be viewed as irreversible, especially since so much has changed since then with regard to energy supplies, interest in thorium, and recovery of the knowledge that was gained many decades ago. There is a group of students at the University of Cincinnati who have started a petition to ask the DOE to reconsider the decision and to save the U-233 for future development efforts.
Hat tip to Kirk Sorensen at Energy from Thorium for his continuing efforts to spread the word and keep the conversation going about the use of this valuable resource that should not be considered to be a waste product.
Here is a comment that I posted on Frank Munger’s Atomic City Underground blog entry titled U-233 project in flux; pricetag’s on the rise. My comment followed one by a reader named Mike who mentioned that the project was similar to blending the gold in Fort Knox with silver to reduce it to something that did not need as much security.
I have to agree with Mike. Refined U-233 is a “special nuclear material” that can produce valuable heat, with special utility as the igniter for reactors that turn thorium into useful fuel.
It is a resource that should be put to use, not a waste product that needs disposal. It is especially offensive to think that the Department of Energy would even consider spending nearly half a billion dollars to turn this cache of something with an energy value that makes it worth more than gold into a far less valuable product and then burying that still valuable material in the Utah desert.
Every gram of U-233 contains a MegaWatt-day of heat. That is nearly 82 million BTUs. The current wholesale market price for on million BTUs is about $5.50 if it is natural gas and about $12.00 if it is oil.
Every pound of U-233 thus contains
82 million BTU/gram x 454 grams/lb x 5.5 $/million BTU = $204,000 worth of heat.
Actually, I am exaggerating to make a point. Despite the fact that nuclear heat is cleaner and more concentrated than heat from gas or oil, nuclear fuel vendors only charge their customers about 50 cents per million BTU for manufactured fuel. About 25% of that price is for the fissile material, so my initial computation based on heat value overstates the current market price of U-233 as a fissile isotope by a factor of about 44.
At $4600 per pound, U-233 would have a value about 1/4th of the value of gold. The value it would have in converting fertile material to fissile material in a thermal breeder is much harder to quantify.
Publisher, Atomic Insights
Note: This post has been corrected. In its original form, it incorrectly implied that gold was priced at less than $4600 per pound; gold’s current price is $16,500 per pound.