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RE: NRC News release on Terrorists.
Jaro
Thank you for your reasoned reply. It is unfortunate that some people, in love with and burdened with excessive opinions find it necessary to clutter the bandwidth
with their ego and nastiness. May calmness and peace prevail.
Joe
9/27/01 2:04:52 PM, "Franta, Jaroslav" <frantaj@AECL.CA> wrote:
>
>
>
> -----Original Message-----
> From: Jacobus, John (OD/ORS) [mailto:jacobusj@ors.od.nih.gov]
> Sent: Thursday September 27, 2001 1:14 PM
>
> To: Franta, Jaroslav; Radsafe (E-mail)
> Subject: RE: NRC News release on Terrorists.
>
> Jaro,
> I don't think you would say that the WTC buildings were fragile. They
>
> stood for over an hour after inpact. Will a four foot thick, reinforced
> concrete wall do as well? If you don't know, say so.
> -- John
> <><><><><><><><><><>
>
>
> John, the reference books I have say that sprayed asbestos or mineral
> fiber covering on steel columns has a fire resistance rating of roughly
> 2hrs per inch of thickness (more precise numbers depend on construction
> details, materials, quality, etc.).
> Concrete offers roughly the same fire protection per unit of thickness,
> for the steel rebar inside.
> But with wall thickness measured in FEET for NPP containment domes, we're
> looking at a fire rating measured in DAYS, not hours (there is, in
> addition, usually a steel plate liner on the inside surface of the dome).
> PS. thanks for your expression of confidence, saying "I don't think you
> would say that the WTC buildings were fragile." ...indeed, if you check
> what I actually wrote (see below), you will note that I was talking about
> the sprayed-on fireproofing material, not the steel structure. I don't
> have any figures handy at the moment on the relative strength of
> sprayed-on fibrous material versus concrete in dome walls, but I presume
> its quite substantial (flame away if you must....).
>
> Jaro
>
> -----Original Message-----
> From: Franta, Jaroslav [mailto:frantaj@AECL.CA]
>
> Sent: Thursday, September 27, 2001 11:19 AM
> To: Radsafe (E-mail)
> Subject: RE: NRC News release on Terrorists.
>
>
>
>
> OOOOPS -- I guess John meant burning jet fuel from the airliner !
> (thanks Phil !)
>
>
> ...but if nothing gets through the wall, what difference does it make
> ? (ignoring destruction of the "balance of plant" for the moment).
>
>
> As we saw in the WTC disaster, much of the fuel was gone in the
> initial fireball. I suspect this would be even more so in the case of
> a disintegration of an airliner on the outside of a containment
>
> dome.... in contrast to the WTC, where a significant fraction spilled
> throughout the interior of the structure and ignited any combustible
> materials there....
>
>
> Also, in chemical/petrochemical industry, large concrete basins are
> used for emergency/accidental spills to safely burn-off the flammable
> liquid.
>
>
> I think there is a big difference between the relatively skimpy &
> fragile fireproofing of steel structures in highrises, and rebar
>
> embedded in four-foot thick concrete walls !
>
> Jaro
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