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Re: So, is reprocessing in America's future?



Franta,

Thank You for your cogent response and cited references.



But, please,let's not get hung up on the pro-nuke/anti-nuke thing that

taints so much of what radsafe folk have to say that is otherwise valid and

informative..



       "Please inform yourself before jumping to the conclusions propagated

by

        antinukes & sympathetic media types."



 I am anti-nuclear in persuasion and don't mind arguing, but I'm just asking

questions. I can't speak for Franz who made the asssertion that CANDUs were

deliberately used to produce bomb grade material,



        "Yes, you are. India has not scavenged, but deliberately produced  b

o mb -

         plutonium (at least for sure for their first bomb exploded decades

ago) in

         their CANDU-power-reactors (heavy water cooled and moderated

natural

         uranium reactors), which are because of their construction suitable

to easily

         change the fuel rods after a short irradiation time without

interrupting power

         production. From these fuel rods  b o m b - plutonium is

extracted."



 but it seems to me that Franz is a learned individual and very much

pronuclear. That said, and forgive me for preaching, perhaps you would be

willing to say: At 10GWd/tonne, what percentage of Pu - 240, 241, 242 would

be present in CANDU fuel?

                                                                      Thanks

Again,



Ray

----- Original Message -----

From: Franta, Jaroslav <frantaj@AECL.CA>

To: <radsafe@list.vanderbilt.edu>

Sent: Wednesday, July 04, 2001 12:35 PM

Subject: RE: So, is reprocessing in America's future?





> Raymond Shadis wrote :

>

> > Franz,

>  Quite so! On line refueling. Have you references that confirm they pulled

> their fuel at low burn-up right under the noses of Canadian and IAEA

> oversight? Does anyone have data or references regarding the Pu-240 levels

> in the fuel the Indians "scavenged" for their bomb? I apologize for the

use

> of the term , "scavenge" , I meant it in the loose sense of drawing off a

> minor portion. Thank you for your patience.                          Ray

> <><><><><><><><><><>

>

> COMMENT :  NOT SO FAST !!  ....many years ago - I guess after the TMI

> accident - before I joined AECL, I asked whether the CANDU fuelling

machine

> could be used to "defuse" a potential meltdown accident by simply

> de-fuelling the reactor core (or at least the central part of it), to

reduce

> the heat load. To my surprise, I was told that the machine works only very

> slowly, so there is no question of it being useful for such a purpose.

> Now I know better.

> Turns out the fuelling machine operation is so slow, you could NOT shuffle

> the thousands of fuel bundles in & out of the core fast enough to get the

> required low fuel burnup that gives bomb-grade Pu. At best, you could do

it

> with a few specific pressure tubes within the reactor, but that would give

> you only a small fraction of the "theoretical" yield, and it would be

plain

> as day that you are trying to do something weird (and as someone else said

> already, you can't just walk out of the plant with spent fuel bundles

under

> your coat anyhow....).

> Alternately, you could do periodic shutdowns to give yourself time to do

> complete core refuelling, but this would also be very obvious to IAEA

> inspectors, and you would essentially destroy the usefulness of the plant

as

> a steady power-producing source. It is for the latter reason that the

> military find it much more economical to just build dedicated

Pu-production

> reactors instead of entire plants with steam turbines, condensers, cooling

> towers, auxiliary process systems, etc., etc.

> I don't know that much about the Russian RBMK reactors, but I suspect they

> have the same limitations as CANDUs. Of course the Russians - like the

US -

> have/had plenty of dedicated Pu-production reactors. I also think that

RBMKs

> have a close relationship to their Pu-production ancestors, but only for

> reasons of convenience/experience. The US too once considered developing

> Hanford-type reactors into full-blown power plants....

> ....I was in the audience at Dr. Edward Teller's last visit to Montreal

some

> years ago, where he recounted his story of the safety committee which

> rejected that idea, on the grounds that the water-cooled,

graphite-moderated

> reactors suffered from precisely the type of potential instability that

lead

> to the explosion of the Chernobyl reactor.

> As for India, it is well known that their Pu came from the CIRUS research

> reactor - although this fact is frequently ignored, on purpose, by the

media

> and by antinuke activists, in order to play up the weapons proliferation

> issue vis-à-vis foreign NPP sales. For details, PLEASE see the following

> web-posted discussions:

>

> "Did India use a CANDU reactor in the 1970's to make an atomic bomb?" at

> http://www.freenet.carleton.ca/~cz725/cnf.htm#x1

> "What is the relevance of Canadian technology to India's recent nuclear

> weapons tests?" at http://www.freenet.carleton.ca/~cz725/cnf.htm#x1_2

> and

> "How easily can an atomic bomb be made with spent CANDU fuel?" at

> http://www.freenet.carleton.ca/~cz725/cnf.htm#x2

>

>

> A couple more points : Since CANDUs use natural uranium, they can't get as

> much fuel burnup as PWR-type reactors (actually less than about one third

as

> much -- 10GWd/tonne vs. some 30 - 40 GWd/tonne for PWRs) . Its NOT enough

to

> make a big difference in the Pu-240, 241 & 242 content (for bomb-building

> purposes), but if you REALLY believe that the Pu isotopics don't matter,

> than the preferred way to go for your bomb-building effort is the PWR,

since

> the total concentration of Pu in the spent fuel - all isotopes combined -

> will be higher by about the same ratio too.

> Lastly, nuclear weapons decommissioning in recent years has demonstrated

the

> relative importance of weapons grade Pu versus weapons-grade Uranium --

the

> surplus quantities of the latter (U-235) are over TEN TIMES as much as the

> former, measured in the hundreds of tonnes, rather than mere dozens of

> tonnes.

> Please inform yourself before jumping to the conclusions propagated by

> antinukes & sympathetic media types.

> Thanks.

>

> Jaro

> frantaj@aecl.ca

>

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