Rich Ulrich wrote:
>
> On Thu, 07 Sep 2000 02:20:27 GMT, Thomas Gatliffe
> <[EMAIL PROTECTED]> wrote:
>
> > Rich Ulrich wrote:
> >
> > > An example in English: I think this underlies the delicacy needed in
> > > the control of a nuclear power plant (in the most common U.S. design).
>
> > Actually, once a power reactor has been brought slowly but correctly into the
> > normal operating condition, it doesn't really require all that much delicacy. It
> > becomes pretty much self-controlling. The temperature of the primary coolant
> > determines its effectiveness as a neutron moderator and how well neutrons are
> > able to remain within the reactor to initiate another fission or be lost to other
> > possibilities such as absorption in a control rod or other non-fissionable
> > material before reaching the apropriate thermal energy level. The temperature of
> > the primary coolant is a function of the balance between power produced in the
> > core and power extracted for energy applications. If more power is extracted,
> > the primary coolant cools and becomes a more effective neutron moderator
> > increasing the flux of thermal neutrons and causing the fission rate to increase,
>
> - so the temperature of the pressurized water has soooo much effect
> on its neutron-absorbancy, that it can be used as an effective
> feedback control on the reaction.
>
> I don't know about your standards, but that sounds a little-bit
> delicate, to me, since it implies 100% control over all outside
> sources of variation in the temperature. Doesn't it?
>
> And loss-of-coolant leads to INCREASED reaction.
>
> During the TMI incident, they worried that there was a hydrogen bubble
> imitating loss-of-coolant. I don't remember if it really was, or not.
FYI IIRC there was not, nor was it ever really a possibility.
rest snippd
Regards,
Russell
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