First Shot at Defining the Main Problem

Forgive me for being so bold as to post my naive comments at this point.
I have never seen a Dogbone in person and have certainly not ever designed or built one.
Given that, I still have formed some opinions and observations.

It seems to me that we are designing a device that is somewhat like a Nuclear Power Plant, something
like a Coal-Fired Power Plant and something like a Propane Gas Grill.

Let us first look at Fission Power Plants and how they are controlled.

To control a nuclear power plant, we need to have a means of slowing down the reaction.  Control rods
that absorb some of the neutrons are used in this case.  When nuclear chain reactions are present, we
are apt to operate either at a subcritical point or an supercritical point.  Either we don't get enough of  
our chain reaction or we get too much of it and have a melt down.  When we are operating subcritical,
we get a COP of 1.2 or so.  When we are operating supercritical, we get a COP of 10 for awhile and
then burn out...meltdown.  So far, Parkhomov and me356 seem to be spending some time operating
subcritical and when they try to boost the COP they end up operating in the supercritical region of the
curve and they are having meltdowns.  
www.e-catworld.com/2015/03/21/mfmp-reports-parkhomov-
breakthrough-90-minutes-of-excess-heat/

Fission plants use Control Rods to moderate the reaction. These are made with neutron-absorbing
material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control
the rate of reaction, or to halt it.  This is fine, but very slow.  Another means is needed that reacts more
quickly to the situation.  In fission power plants, most of the neutrons are released promptly, but some
are delayed.  These delaying mechanisms are crucial in enabling a chain reacting system to be
controllable and to be able to be held precisely at the critical level.  

What is our moderator?   What are we absorbing and retaining for a bit to slow the reaction down?  Do
some isotopes of Ni act as a moderator?  Perhaps Ni64, due to its half-life and beta emission
capabilities  (T½ = 12.7 hours)?

The "Coefficient of Reactivity" is the curve that describes how any reactor responds to an increase in
temperature.  A "
Void Coefficient of Reactivity"is different and plots what is happening to that curve
when we start to get bubbles in the water coolant.  Chernobyl is an example of a reactor that had a
positive portion of their Void Coefficient of Reactivity.  When they hit that portion of their curve, it
melted down (or melted up, if you prefer).

Do we have a negative slope in our Coefficient of Reactivity Curve over the whole range of our
operating temperatures?  
Do we have a negative slope in our
Void Coefficient of Reactivity Curve over the whole range of our
operating temperatures?

We should, but it appears that we have not yet met this requirement.

Next, let us look at Coal Fired Heating Plants

In a coal fired plant, we have a source of coal and a source of oxygen to control the rate of burning.  We
also have a source of cool water to keep the boiler within an acceptable range of temperatures.

How about Propane Fired Outdoor Grills?

In a Propane Outdoor Grill, we have a source of C3H8 and a source of air/oxygen.  We can control the
amount of C3H8, but we cannot starve it for air lest we build up unburned Propane.

We have heard that Dogbones can have a rapid rise in temperature.  Is this more analogous to a
buildup in Propane or is it more like hitting a supercritical nuclear reaction?

The hotter something gets, the more rapid its heat gets conducted away from it.  

Can we control a dogbone simply by running enough cold water over it or do we need moderators on
the atomic level?

don

http://youtu.be/4fCBu2MLbFU

http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/u235chn.html

A nuclear meltdown is an informal term for a severe nuclear reactor accident that results in core
damage from overheating.  A meltdown may be caused by a loss of coolant, or low coolant flow rate or
could be the result of a criticality excursion in which the reactor is operated at a power level that
exceeds its design limits.  A loss of coolant accident is called a LOCA.  If the plant has not been
designed correctly, they may have a portion of the coefficient of reactivity curve where the slope was
positive and a chain reaction takes place.

In extreme cases the reactor may proceed to a condition known as prompt critical. This is especially a
problem in reactors that have a positive void
coefficient of reactivity, a positive temperature
coefficient, are overmoderated, or can trap excess quantities of deleterious fission products within their
fuel or moderators. Many of these characteristics are present in the RBMK design, and the Chernobyl
disaster was caused by such deficiencies as well as by severe operator negligence.

At Chernobyl, they had a portion of their coefficient of reactivity curve that was positive and when
they went through a maintenance cycle they hit this portion of the curve and it resulted in a melt-down.

At Fukushima and Three Mile Island the problem was lack of sufficient coolant.

Lucerne experiments are run without any coolant other than the air in the room.  me356 is currently
redesigning his device to add coolant.  Will this stabilize the reaction or merely keep it so far below
criticality that the COP is low?

Our goal is to design a system with a negative coefficient over the whole range of temperatures so that
we don't have meltdowns.  

Fuel temperature coefficient of reactivity
The change in reactivity per degree of change in the temperature of nuclear fuel. The physical property
of fuel pellet material (uranium-238) that causes the uranium to absorb more neutrons away from the
fission process as fuel pellet temperature increases. This acts to stabilize power reactor operations.

More on Void Coefficient of Reactivity.
Rossi knows that if he hears bubbles in his boilers that something bad might eventually happen.
Here are his comments on using a stethoscope on the one-megawatt unit;
Dr Joseph Fine:  May 9, 2016 at 1:27 PM
www.RossiLiveCat.com
The stethoscope is useful not to reveal immediate phenomenons, but to prevent meny negative events
days if not weeks before they happen. I give you a paradigmatic example: with the stethoscope used
everyday, I can hear the fact that a sector of the boiler is working better and more regularly than
another. This phonomenon at its beginning is easy to correct, and the situation is easy because it can
take, as I said, days if not weeks before the situation becomes important. So the correction is easy and
calm.
Obviously this “ex impromptu” proceeding is not a substitute for an electronic control, that reacts in
milliseconds once the phenomenon is already enough developed to affect the sensors. Electronic control
is born by rationality and logic in Boolean language and is necessary; ausculting with a stethoscope is
an art that talks to the instinct of the very skilled expert of the art: it is useful, mainly in R&D stage, but
not necessary.
I made my work with the stethoscope mainly in SSM mode, because the plant worked mainly in SSM
mode.
The information given by the stethoscope is rich and diversified. Electronic controls cannot substitute
my stethoscope and vice versa, as well as rational logic cannot substitute instinct and vice versa.
I am not a normal operator that uses only normal controls. I am something substantially different, as
well as my work is not normal. This does not mean I am better, just means I am different.
Obviously I too need, also for safety reasons, to have the due electronic control devices installed. But it’
s not enough, the instinct needs more “antennas” and the stethoscope is one of them.
Warm Regards,
A.R.



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