Nuclear power plant with a reactor

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).

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