[ RadSafe ] IFR and TWR with Bill and Melinda Gates Inteview on 60 minutes. What's Killing The Nuclear Industry?

Jaro Franta jaro_10kbq at videotron.ca
Sat May 18 14:11:08 CDT 2013

I haven't seen any updates in the last couple of years on TerrPower's TWR,
but presumably the design keeps evolving.....


And from another publication.....

Fuel Cycle Analysis of Once-Through Nuclear Systems
Prepared for
U.S. Department of Energy
Systems Analysis Campaign
T. K. Kim and T. A. Taiwo
August 10, 2010

3.6 TerraPower Traveling Wave Reactor Concept

The Traveling Wave Reactor (TWR) concept being developed by TerraPower is
intended to provide a technology pathway for fast reactors that do not
require reprocessing facilities and a system that offers a high fuel
utilization [Ellis 2010]. The system adopts the breed and burn concept in a
fast reactor, relying in the use of depleted uranium fuel to generate a
significant fraction of the system power. The system will have no external
fuel refueling but will allow internal fuel shuffling. Similarly to all
breed and burn concepts, the initial core of the TWR requires some amount of
fissile fuel, which is currently assumed to be enriched uranium fuel. Since
the intent is a regime with no fuel reprocessing, the use of transuranic
elements derived from LWR used nuclear fuel is not an option. TerraPower
speculates that the TWR should be able to achieve a uranium utilization that
is 40 times greater than that of current LWRs.

The current version of the TWR design is based on elements of sodium-cooled
fast reactor technology that have been tested in a large number of
one-of-a-kind reactors over the years. Conceptually, the core consists of
hexagonal fuel assemblies containing enriched uranium fuel or depleted
uranium fuel. The core arrangement is such that the breed and burn wave does
not move, but is "stationary". This stationary wave is achieved by
periodically moving fuel material in and out of the breed and burn zones
(shuffling). Metallic fuel is considered for the design because it offers
high heavy metal loading and excellent neutron economy. Zirconium is used
for alloying the metallic fuel to improve the dimensional stability of the
fuel during irradiation and to inhibit low-temperature eutectic and
corrosion damage of the cladding.

TerraPower is now considering the "repurposing" (or re-cladding or
reconditioning) of the fuel following use. This is to allow the high burnup
in a given pass through the core to be increased to a much higher value
(about 50%). This repurposing could involve a simplified reprocessing step.
In the paper by Ellis et al., the proposed approach is melt refining [Ellis
2010]. This is a new twist to the TWR concept. The evolving reactor design
and associated fuel cycle for the TWR is however to be expected.

The activities on the TWR design are proprietary to TerraPower LLC.
Information is provided here to inform USDOE efforts on assessing advanced
reactor concepts.



-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of David Lee
Sent: May-18-13 2:44 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] IFR and TWR with Bill and Melinda Gates Inteview on
60 minutes. What's Killing The Nuclear Industry?


Thank you, for explaining it so nicely. My memory, is not as well as it used
to be, so I am not sure, if I ever heard of this reactor concept before.

I did not know that you guys at Argonne worked on such sophisticated and
cool things! kudos to you guys, I am very impressed!!!
Fissile trigger and breeder in within in waves. I bet it was exciting and
exhausting to do reactor design calculations.

On Fri, May 17, 2013 at 10:14 AM, George Stanford
<gstanford at aya.yale.edu>wrote:

> David:
>       No, not heavy water (not even heavy water could make depleted 
> uranium go critical -- CANDUs can use natural uranium).
>   .  TerraPower's TWR (Travelling Wave Reactor) is a variant of the 
> IFR (Integral Fast Reactor) developed at Argonne National Laboratory.  
> It will use metal fuel and be cooled by liquid sodium (no moderator).
>      Both IFR and TWR need an initial charge of fissile material 
> (U-235 or Pu-239), and then they breed enough new fissile to keep 
> themselves going indefinitely, using ~1 ton of depleted uranium per 
> GWe-year of energy produced.  The main difference is that the TWR 
> would be loaded with 60 years-worth of fuel from the start (i.e. 
> something like 80 tons per GWe), whereas the IFR would recycle its 
> fuel much more frequently, adding fresh depleted periodically, and thus
would be very much smaller.
>      George S. Stanford
>      Reactor physicist. retired from Argonne National Laboratory
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~**~~~

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