Rum RBMK
The world’s first nuclear power plant used a uranium-graphite reactor
AM-1 , – similar in design to the above-mentioned PUGR. AM-1
became the world’s first power reactor, i.e. reactor, chief
whose purpose is to generate electricity. As
fuel for it was also used uranium, or rather, uranium dioxide
UO 2 enriched in the isotope 235 U. The moderator, as in the PUGR, was
graphite.
In our country, a decision was made on the further development of uranium
graphite reactors. As a result, the Beloyarsk NPP was
power units with the AMB-100 and AMB-200 reactors – in 1964 and 1967, with
responsibly. But even these attitudes became only an intermediate stage.
In 1973, the first power unit was launched at the Leningrad NPP.
an actor of RBMK-1000. RBMK stands for High Power Reactor
Channel “, and 1000 is its electrical power, measured in meters
gavattah (MW). RBMK-1000 became the first large-scale energy
a chemical reactor: it generates 10 times more electricity,
than the AMB-100 reactor, and 200 (!) times more than the world’s first energy
hetic reactor AM-1 (whose power was only 5 mega-
watt). Is 1000 megawatts a lot or a little? To understand, imagine
to itself: operating at full power, the RBMK-1000 will be able to supply energy
20 million 50W bulbs each. Four power units RBMK-1000 of the Leningrad NPP can almost completely provide
to supply electricity to such a large city as St. Petersburg.
We especially note that the basic structure of the RBMK remained the same
kim the same as in the first industrial reactors – PUGR, the same as
at AMB installations. RBMK, like PUGR, is uranium-graphite
reactor. It is also fueled by uranium dioxide UO 2 , enriched
fissile isotope – 235 U. Moderator and reflector
neutron is graphite. The reactor, like bricks, is made of graphite
commercial blocks measuring 250x250x600 mm, their total weight is about 2000
tons. Of course, not ordinary graphite is used for the reactor. Here
an extremely pure material is required – graphite of nuclear grade
you practically do not contain impurities absorbing neutrons.
When building a reactor from these graphite blocks, it was required to use
key accuracy: for example, I had to write off the “Kir-
pici “even with the slightest chip on the edge.
Each graphite block has a hole in which to insert
technological channel. And in the technological channel, in turn,
a fuel cassette filled with uranium fuel is inserted
vom (Fig. 4.6, 4.7, 4.8). It turns out that the RBMK-type reactor is designed to
quite simple (and this is one of its main advantages); it consists
from a set of identical elements – a section of masonry made of graphite
pich and the technological channel passed through them ).
Figure 4.6 – Fragment of the RBMK-type reactor core
(view from above)
The reactor is located in a concrete shaft that serves as a biological
physical protection (i.e., protection of personnel from radiation).
Let’s take a closer look at how the conversion process takes place.
nuclear reaction energy into electricity in the RBMK reactor. In the asset
zone, the device of which is described above, is a chain reaction
fission of uranium nuclei, resulting in a colossal
energy and nuclear fuel heats up. But this energy is thermal, and
not electrical ; it cannot be directly converted into current. Therefore, in ac-
thermal energy is transferred to the coolant –
water . Water is fed into the core from below, heats up and turns
in steam (see fig. 4.9). But not all water becomes steam – from active
Figure 4.8 – Design of a RBMK type reacto
R
Figure 4.7 – Fuel assembly (FA) of RBMK reactor
the zone leaves a mixture of steam with water. To separate steam from water, this
the mixture is run into a special apparatus – a separator drum. Steam
must be separated from the water because it goes to the steam turbine
well: getting inside the turbine through the inlet nozzles, steam hits the shovels-
turbine chambers, forcing them to rotate (see Fig.4.10) – respectively,
if the water content in the steam is too high, the turbine will
will take a sip ”and will fail. All blades are fixed on the turbine shaft
us. The turbine shaft is coupled to the generator shaft : it means when
the turbine shaft rotates, at the same time the electric generator shaft rotates
rator. In this case, an electromagnetic field arises in its windings, and
electric current is generated, which is released to the consumer
lyam – to industrial enterprises, utilities, population
niya. What happens to the steam next? When he works on the turbine,
it is cooled, while the steam condenses – that is, it turns
back into the water. This water (feed water) is purified and directed
into the separator drum, mixing with the separated (separated
from steam) with water supplied there from the core. Then this water
the main circulation pump is again fed into the reactor, and the cycle
repeats (see fig. 4.9).
Figure 4.9 – Scheme of a power unit with a RBMK-type reactor
Figure 4.10 – The principle of operation of a steam turbine
Note that the technological scheme of the RBMK power unit is
is a closed loop designed in such a way that radio
active steam and radioactive water from the reactor could not get into
and thus become a source of radiation hazard for
population and environment. In RBMK-1000, water boils and transforms
goes into steam directly in the reactor, and the steam obtained from it,
goes straight to the turbine. Therefore, the installation with RBMK is called one
tour. The RBMK-type reactor is one of the main reactors operated
in our country. In total, we have 31 nuclear power units,
11 of them are blocks with RBMK-1000, which generate about 47%
of all “nuclear” Russian electricity (for 2009).