erickson - fusion-fission hybrids

8/7/2019 Erickson - Fusion-fission Hybrids

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Fission-Fusion HybridReactors

Lawrence Erickson


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Why should we care about

hybrids? Proliferation!

Economics!


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Use as a breeder reactor

Breeder reactors can make fissile material

(U-233 or Pu-239) out of non-fissilematerial (Th-232 or U-238).

With current breeder technology, onebreeder can serve one other reactor.


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Proliferation

Because they produce fissile materials

that can be chemically separated from thereactor, every breeder reactor is apotential proliferation risk.

So, how do we breed fuel while minimizingproliferation?


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Fusion Breeder

A DT fusion reactor produces a large amount

of neutrons, which can be used to breedenough fuel for 10 satellite reactors.


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Proliferation/Economics

Fewer breeders means lower proliferation

risk. Also, fusion breeders can make U-233 instead of Pu-239. U-233 is harder toseparate from nuclear fuel.

Fusion is not currently economicallyviable. Creating a fusion/fission hybridcould spur more research, which couldeventually lead to an economical purefusion reactor.


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Who is doing research?

Not very many people. Most of the

literature on the subject dates from the mid1970s to the early 1980s.

A depressing paper from 1984(Taczanowski) declared that fusionbreeders could never be an economicallyviable alternative to fission breeders.


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Wallace Manheimer

Retired from Naval Research Laboratory.

Is interested in fusion/fission hybrid notonly for proliferation and economicreasons, but also for military propulsionreasons.

Claims effective Q of hybrid would bearound 10 given current technology.


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Potential Problems with Manheimer

Has been criticized for not fully developing

his plan.

Appears to be calling for other scientists todo research.

Has been criticized for lacking thequalifications to do proper research.


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Hybrid Reactor BlanketDTCore

FertileBlanket

LithiumBlanket

CoreWall

GraphiteReflector


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Research into blanket material

Pure lithium is unsuitable to use in the

reactor blanket, but there are severallithium salts that could be used instead.

Mustafa Ubeyli is currently investigatingvarious salts at Gazi Universitesi inAnkara.


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Further research by Ubeyli

Investigation into the geometry of the

reactor blankets.

Investigation into high level fission wastetransmutation in hybrid systems.

Appears to be the only researcher stillpublishing about hybrid reactors.


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Summary

Potential security and economic benefits.

Much of the work that has been performedon the subject is either theoretical or

economical. There is no large-scale effort to makehybrid reactors a reality.

Small amounts of work are being done onsubproblems.

erickson - fusion-fission hybrids

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