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Thorium bred Uranium-233 can be used to make atomic bombs

Thorium Nuclear Bombs (Shorter version)  Kevin Meyerson, kevinmeyerson.wordpress.com 9 Oct 12, Thorium bred Uranium-233 can be used to make atomic bombs, despite what proponents may claim.

You don’t have to trust me on this, see what the experts at various institutions have to say below:

MIT Energy Initiative, The Future of the Nuclear Fuel Cycle

Appendix A starts on page 181 of the Appendices PDF file. The relevant statement from MIT is:

• Proliferation And Security Groundrules:
  Irradiating thorium produces weapons-useable material. Policy decisions on appropriate ground rules are required before devoting significant resources toward such fuel cycles. U-233 can be treated two ways.

• Analogous to U-235. If the U-235 content of uranium is less than 20% U-235 or less than 13% U-233 with the remainder being U-238, the uranium mixture is non-weapons material. However, isotopic dilution in U-238 can significantly compromise many of the benefits.
• Analogous to plutonium. Plutonium can not be degraded thus enhanced safeguards are used. The same strategy can be used with U-233. A complicating factor (see below) is that U-233 is always contaminated with U-232 that has decay products that give off high energy gamma radiation which requires additional measures to protect worker health and safety. There has been no consensus on the safeguards / nonproliferation benefits of this radiation field.

The point being made here is that thorium can be used to make Uranium-233, which in turn can be used to make bombs. The complicating U-232 contamination mentioned above is what many of the thorium proponents refer to as making thorium resistant to proliferation. MIT has more to say about this proliferation protection in their summary:

On one hand, high radiation dose [from U-232 decay] provides self protection to separated fissile material against diversion and misuse. On the other hand, it makes the U-233 recycling more complex and costly.

The point here is that the U-233 is in fact subject to ‘diversion and misuse’ (like atomic bombs) if it can be separated out from the highly radioactive U-232 contaminants. If the U-232 is not somehow processed out, however, there is no way to operate the reactor for peaceful purposes, or otherwise.

Oak Ridge National Laboratory

Filtering contaminants out of thorium bred U-233 to make weapons grade fissile material is not rocket science. Oak Ridge National Laboratory (ORNL) created a process to do this. They kindly wrote about it in a history included in the ORNL Review publication (search the long page for the words “THOREX” or “Uranium-233″):

By 1954, the Laboratory’s chemical technologists had completed a pilot plant demonstrating the ability of the THOREX process to separate thorium, protactinium, and uranium-233 from fission products and from each other. This process could isolate uranium-233 for weapons development and also for use as fuel in the proposed thorium breeder reactors.

There are no technical issues for separating out Uranium-233 for weapons development.

UK National Nuclear Laboratory

The United Kingdom’s National Nuclear Laboratory (NNL) prepared a position paper on the thorium nuclear fuel cycle. It is pretty straightforward:

October 9, 2012 - Posted by Christina Macpherson | 2 WORLD, Reference, Uranium, weapons and war