Re: OT: Nuclear Waste (Was Re-Marketing Ada)

["Robert I. Eachus" <rieachus@comcast.net>]

> On 2003-11-19, Robert I. Eachus <rieachus@comcast.net> wrote:

(No, I didn't.)



Preben Randhol wrote:

> While nuclear plants may be safe (depending on design) while operated
> properly, what would happen if one was attacked by terrorist? What would
> have happened if the morons had crashed a plane in a couple of nuclear
> plants and not in the Twin Towers? 

1) Everyone on the plane would get very dead.

2) If they crashed into the containment building, the plant could keep 
operating.  If they crashed several planes into the same containment 
building, they might penetrate it.  That doesn't mean the reactor would 
be damaged, but that the containment building around it could probably 
be breached by several fully-loaded 747s hitting the same spot. (The 
requirement for US nuclear plants is that they survive ONE crash of a 
jetliner full of fuel, not several in succession.

3) If they crashed into the turbine hall (where the electricity is 
generated).  There would probably be a LOCA (loss of cooling accident), 
the reactor would shut down, and the ECCS (emergency core cooling 
system) would kick in.  You can look at the plans for any particular 
nuclear plant to see if it is possible for an aircraft crash to damage 
both the regular and emergency cooling systems.  But believe me, for 
every nuclear plant in the US, those studies have already been done as 
part of the plant's certification process.

4) If the plant was a boiling water reactor (BWR) built by General 
Electric, there would be some tritium (radioactive hydrogen) in the 
steam released.  Of course, anyone exposed directly to this steam would 
also be killed, but not by its radioactivity.  This tritium, with a 
half-life of ten years could possible seriously contaminate water 
supplies downwind of the disaster.*  Studies on LOCA releases indicate 
that this is a low-probability scenario.  Normally, even without all 
that burning jet fuel, the "bubble" of water vapor created gets carried 
into the stratosphere, where the tritium decays to normal levels faster 
than the water vapor is exchanged into the lower atmosphere.  Think of 
the bubble as a lighter than air balloon.  Even HTO has a molecular 
weight of twenty (1+3+16) compared to around 28 for air (mostly N2).

*I'm not worried.  To do that would require that the terrorists hit the 
turbine hall in a driving rainstorm--at least twice.  An experienced 
pilot might be able to fly that low in bad weather in a commercial 
jectliner, but I think that a plane crashing into a turbine hall in such 
circumstances would be an accident--even if it had been hijacked.

-- 
                                           Robert I. Eachus

100% Ada, no bugs--the only way to create software.