[cdn-nucl-l] Re: Global Climate Change

[Simon Day <dayse@mcmail.cis.mcmaster.ca>]

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

vladobrankov@icqmail.com

Dear Mr. Day

I was adviced by Mr. Rouben to send you the text below
and to put it in the Canadian Nuclear Discussion list.

Thank you.
Vladimir Brankov



> Reply to the Message from the Government of Canada
> (about the global climate changes )
>
> I am writing for something that can be done now,
right away, and I was impulsed
by the TV clip of the Canadian Government.
>         There is a NPP in Bulgaria called " Kozlodui"
with six nuclear block
units. Two of them will be stopped until the end of
this year and another two
will work 3 years more and will share the doom of the
first two. These four units
have total capacity of 1760 electrical MegaWatts.
>         At present it is accepted the exploitation of
a NPP to be  no less than
40 years. There are between 10 and 20 years extra life
in every of the above
mentioned units. If there is a chance for them to work
they will prevent the
earth's athmosphere from huge amount of CO2 pollution.
>         I will calculate here the approximate amount
of this pollution.
>         Let:
>                 f    is the factor of power use(
about 0.8 )
>                 N   is the power( 1760 MW=
1,760,000kW )
>                 T   is the time( the hours in 15
years )
>         Then the produced electrical energy will be
>                 W= f*N*T= 0.8*1,760,000*(24*365*15)
> =185,011,200,000 kWh
>         It is 185 billions kWh.
>
>         To be produced the same amount of electricity
by means of a Thermal
Power Plant on coal fuel, will be burned about 65
millions tons of coal because:
>                 B*Q*ef=3600*W    therefore
>                 B=
3600*185,011,200,000/(29300*0.35)=64,947,861,530kg
>         Which is 65 million tons.
>         In the formula above:
>                 B  is the amount of coals in kilograms
>                 Q  is the heat from 1 kg coal (I took
the standard rate of
> 29300kJ/kg)
> ef  is the efficiency of the Power Plant
> W  is the produced energy in kWh
>
>         Because the carbon is a main component in the
organic fuels I accept
about 70% of carbon in the fuel. Then there will be:
>                 (65 million tons)*0.7=45 million tons
carbon in the coals.
>         The carbon dioxide is the product of the
carbon burning. Because every
12 tons of carbon use 32 tons of oxygen, the amount of
the carbon dioxide will be:
>                 (45 million tons)/12*( 32+12 )=165
million tons
>         And there will be consumed
>                 (45 million tons)/12*32=120 million
tons of oxygen
>
>         I want to emphasize that the carbon dioxide
is one of the two
greenhouse gases and that the Nuclear Power Plants do
not produce this gas and do
not contribute for the global climate changes.
>
>         Why these 4 units will be stopped?
>         In the early nineties this Power Plant was
thought as one of the most
dangerous Nuclear Power Plant and this was really so.
During the Communist rule
the producing of electricity was the main goal and the
Nuclear Safety was
something not so important. The danger of the Power
Plant wasn't in the
equipment, but was concentrated in the personal
mentality.
>         More than 10 years later this is almost
another Nuclear Power Plant.
The personal is used to think about the production of
electricity with main
priority of the Nuclear Safety.
>         But now there is a political decision that
Bulgaria Must to stop these
4 units and this decision is initiated by the European
Union and supported by
some Bulgarian politicians. The NPP "Kozlodui" became
the main obstacle for
Bulgarian membership in the European Union.
>         Is this NPP dangerous now?
>         I don't think so. This power plant has now
very well trained and
competent personal and well maintained and permanent
modernized equipment. During
the last 10 years there was a big scale improvements in
almost all of the
equipment of the Plant. I will enlist some of them that
are directly in
connection with the nuclear safety:
> Installing new sets of safety valves on Pressurizers
of these 4 units
> allowing to cool the core of the Reactors by means of
the technical water
systems. ( Feed and Bleed Cooling )
> Installing an antiseismic hydro shock absorbers on
the main
> Cooling pipelines of the First Circuit, on the
Steamgenerators, and the
Pressurizers.
> Building of an entirely new system for feeding the
Steamgenerators with water
in the case of failure the systems of
> normal exploitation and  the emergency feed water
system.
> Quick closing valves on the Main Steam pipelines,
preventing the
> sudden cooling down the core in the case of Main
Steam pipeline rupture.
> I can proceed with another 20 sheets of improvements
-in Diesel Generators,
System of Measuring and Control the Neutron flow,
electrical equipment,
regulators, safety valves, and so on and so on.
> After these modernization's and improvements I would
say that as regards the
equipment NPP "Kozlodui" is among the best NPPs.
> The weak side of these units is the lack of
Containment. The equipment of the
Primary Circuit is housed in Confinement ( Box of
Steamgenerators ) which can to
hold against 0.08 MPa  overpressure. There are safety
valves connected with the
atmosphere and they open when the pressure in the
Confinement is greater than
0.05 MPa. This will occur when there is accident with
the Primary Circuit
pipeline rupture. ( diameter of the pipeline is 500 mm
) Then radioactive steam
will be thrown in the atmosphere.
> I think that this problem will be solved if the
confinement is connected with
additional volume, which may be cylindrical shaped and
containing properly formed
and arranged ice blocks and steam distribution devices.
The ice blocks must to
provide a large contact surface. In this case if an
accident with Large Brake
loss of Coolant occurs, the steam thrown to the safety
valves will go in this
volume and will condense. The ice will melt down and
there will be effective
reducing the pressure in the Confinement at the expense
of the phase
transmission. The heat energy of the steam will be
consumed as a Latent Heat of
melting. This solution will make from the Confinements
Containments and will
provide defense of the environment.
> The approximate sizes of this " Ice Condenser " we
can define by means of the
next reasoning:
>         1. There are about 200 tons of coolant in the
Reactor and the
>            Primary Circuit
>         2. The nominal temperature of the coolant is
275 C.
>         3. The Latent Heat of the ice melting is
about 330 kJ/kg.
>         4. Specific Heat Capacity of the water we can
take as 4.2 kJ/kg.
> The heat energy necessary for warming up the coolant
from 20 C to 275 C is:
>         Q=c*m (T2 - T1)= 4.2*(200,000kg)*255= 2.1*108
kJ
> If we want the same amount of heat to be taken by the
ice we will need:
>         2.1*108 kJ/(330kJ/kg)=6.5*105 kg   of ice.
> This is about 650 tons of ice.
> Therefore a cylindrical construction with dimensions:
>         Radius=5m (maximum)
>         Height=15m (maximum)
> will be enough.
> The volume will be
>         V=3.14*R2*H=1100 m3
> The energy necessary to keep this volume cooled may
be defined by sophisticated
and precise methods but now I will use another approach.
> My BC Hydro bill for the period June 10 - July 23 
2002 is 347 kWh.
> Let whole of this energy is consumed by the
refrigerator which volume is about
1 m3. This gives 0.5 kWh/h for 1 m3. For 1100m3 we will
need
> 550 kWh/h. For 15 years we will need about 75
millions kWh. It is practically
nothing compared with 185 billions kWh which the four
Units can produce for these
years.
>         Besides the ecological there is economical
profit. If we admit 8 to 10
cents per kWh for 15 years these Units can produce
electricity for
> 15,000,000,000 $ Now the price of one fuel assembly
is about 120,000 $. There
are 349 fuel assemblies in the Reactor's core and the
duration of one refueling
cycle is 3 years. Therefore for 15 years are necessary:
>                 15/3*349*4=6980 fuel assemblies
>         Even if the price of the fuel increase double
during the period, the
total sum for the fuel will be about 1.5 billion
dollars. Therefore these Units
can finance themselves very successfully.
>         Since the first two Units will be stopped
finally these days and the
third and fourth Units will work only another 2 or 3
years it is obvious that
they are not valuable for the Bulgarian Government.
Therefore they may be bought
almost at the price of a scrap.
>         If some powerful Canadian or other Company,
supported politically by
the ecological initiative of the Canadian Government
buy these four Units, and
with it's experts prove their safety to the European
politicians, this will be
something real done with respect to slowing down the
Global Climate Changes.
>         I will send this letter to Engineering
Organizations and Engineers, and
if somebody can do something let do it.
>         I am not sure that the politicians are able
to decide whether a Nuclear
Power Plant is dangerous or not. If there are
economical interests this Plant not
to work, I would say that if we think now with our
pockets tomorrow we will live
in refrigerators.
>
> Vladimir Brankov
> MS of Thermal and Nuclear Power Engineering
> former Duty Engineer of third Nuclear Power Unit of
NPP "Kozlodui"
>
>  #217-7341   19th Avenue
>  Burnaby B.C    V3N 1E3
>  Canada
   Tel. (604)540-1523



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