The object of the work is to compare and analyze external and internal exposure doses and assess damage to the population living around nuclear power plants with VVER-type reactors (on the Rostov and Kalinin nuclear power plants), within a certain radius, taking into account the wind rose. There will also be proposed measures for the possible addition and refinement of formulas. The method of calculating the doses of external and internal exposure, as well as damage to the population in the ring segment of rumba. External and internal exposure doses for Kalinin and Rostov NPPs have been considered. An assessment of material damage was conducted. A variant of the format of the atlas of risk assessments is proposed. Initial assumptions have been made regarding the discrepancy in the results obtained for both doses and damage. One of the possible reasons for the discrepancy in the results of calculating the dose and damage to the Kursk and Smolensk NPPs may be the difference in the terrain. We need to take this into account. By relief changes we mean not ravines and slopes, but hills, mountains, fields. Additionally, you can consider the type of terrain: steppes, forests, etc., although all this will contribute to the already quite a long distance from the nuclear power plant. In the future, it is planned to continue work on the atlas of risk assessments and think over its more convenient format.
The accident at the Chernobyl nuclear power plant was an event of great social and political significance for the USSR. All this left a definite imprint on the course of the investigation of its causes. The approach to the interpretation of the facts and circumstances of the accident has changed over time, and there is still no complete consensus.
But still the most important thing is people. If we learn to accurately assess the damage that a nuclear power plant can cause in the first moments after the accident, we will significantly reduce the number victims the population.
Comparative risk assessment in an accident at various NPPs gives an idea of the relationship between the amount of damage and external factors (location, climatic conditions, etc.), in this case, the wind rose.
This assessment is relevant, since all nuclear power plants are sources of potential danger. According to the Order of the to carry out work on risk assessment at relevant facilities. In this regard, the definition and comparison of the risk of an Emergency Accident (EA) at a nuclear power plant is a relevant topic.
According to Russian legislation (for example, [2]), the development of a facility safety data sheet is a prerequisite for the operation of such facilities as: hydraulic structures, organizations producing, processing, storing or transporting radioactive, fire and explosive, toxic chemical and biological substances (filling stations, thermal power plants, nuclear power plants, industrial enterprises, etc.), as well as those characterized by an increased risk of terrorist actions (crowded places).
This work is based on the study, further comparison and analysis of the estimates obtained in the calculations for two NPPs: Kalinin and Rostov. A comparative assessment has not previously been carried out, but it will help to understand what factors play a key role in the event of an accident. In this connection, two similar nuclear power plants were chosen: Kalinin and Rostov. They are of the same type and can give us a complete Figure for evaluation.
Rostov NPP is located in the Rostov region, 12 km from the city of Volgodonsk on the bank of the Tsimlyansk reservoir.
The electrical capacity of the four existing power units is 4.03 GW.
Kalinin NPP is located in the north of the Tver region, 120 km from the city of Tver. Distance to Moscow - 360 km, to St. Petersburg - 320 km. The NPP site is located on the southern shore of Lake Udomlya and near the city of the same name. The total area occupied by KAES is 287.37 hectares.
The electrical power of the four operating units is 4 GW. 2.
Comparative assessment of risk indicators will be made based on the formulas proposed in [6]. Damage to one person living in the ring segment of rumba: Σ Σ ∙ ∫ ( )∙ 1( )∙ 0
8 ( ) where: L
– damage to the population in the rumba ring R, r L N DE N1/8 – distance from NPP; – total damage from an accident; – total population; – annual effective radiation dose of the population in the ring segment of rumba, considering the wind rose; – number of people in rumba; DE(year) – annual effective dose to the entire ( ) = segment; population. (1) (2) (3) = ∑ =1 ∙ ∙ < , risk acceptable, 1/year; probability (frequency) of dangerous situations; the level of the corresponding dangerous effects on people; coefficient linking the
probability (frequency) of death to people with dangerous effects (5,610-2 1 / Sv in accordance with [6]). where: DE
The annual effective radiation dose of the population in the ring segment of rumba, taking into consideration the wind rose: ( ) = ∙ ∑ =1 1( ) ∙ ( )( ),
Risk: where:
R PW N1/8
Ra F D k – – – – annual effective dose to the entire population. 3.
We have an opportunity to work with the whole point, but priority is given to the directions with the highest probability of the wind. For Rostov NPP: East direction (probability 0.2). For Kalinin NPP: South-West direction (probability 0.18).
Let us calculate the annual effective radiation dose for the Rostov NPP (mSv). The baseline data and the results of calculating the annual effective radiation dose for the Rostov NPP are presented in Table. 1 [7].
Table 1. Baseline data and the results of calculating the annual
effective radiation dose of the population for the Rostov NPP
R Pw N1/8(i) DE( year) ( i) DE
3 0,2 0 0 0
10 0,2 860 10,5 1806
15 0,2 0 1,91 0
20 0,2 620 1,04 128
30 0,2 512 0,6 61
40 0,2 1044 0,32 66
50 0,2 1342 0,2 54
100 0,2 11186 0,1 234
Let us calculate the annual effective radiation dose of the
population for Kalinin NPP (mSv). The baseline data and the
results of calculating the annual effective radiation dose for the
population of Kalinin NPP are presented in Table 2 [7].
Table 2. Baseline data and the results of calculating the annual
effective radiation dose for the population of Kalinin NPP
R Pw N1/8(i) DE( year) ( i) DE
3 0,18 16158 34 98887
10 0,18 318 13 744
15 0,18 230 4,6 190
20 0,18 598 2,4 258
30 0,18 363 1 65
40 0,18 26349 1 4742
50 0,18 52342 0,61 5747
100 0,18 26511 0,21 1002
It can be seen that the radiation dose for Kalinin NPP is
significantly higher than for Rostov. Firstly, this is due, of course,
to the number of people who live around the NPP data. If we look
at the data for the Kalinin NPP, we note that from the direction
of the most possible wind direction at a distance of 3 km from
the NPP there is a very large number of people: 16158 people.
As for the Rostov NPP, no one lives from the direction of the
most possible wind direction at a distance of 3 km from the NPP.
Secondly, Kalininskaya and Rostov NPP have approximately the
same values for DE (year), but there is a rather large difference
in the relief, which can lead to completely different
consequences. Most of the territory of the Rostov NPP has a flat
and flat relief character. Agricultural production predominates in
this area. Arable land is crossed by forest belts of 15-20 m,
planted mainly by forest forest strata. Rostov NPP is located in
the continental climate zone, with insufficient moisture, hot and
dry summers, and relatively long and cold winters. A distinctive
feature of the climate is the abundance of sun and heat. Unlike
the relief of the territory of the Rostov NPP [7], the territory of
the Kalinin NPP has a dissected relief, the prevalence of absolute
heights and small relief forms. In the middle part of the region,
from the southwest to the northeast, there are uplifts of the Forest
Ridge, which is a spur of the Valdai Upland [7]. The forest ridge
is divided by two large zandrovaya plains: in the east
Srednemozhskaya nisin with absolute heights of 130-140 m, in
the west and south - Vyshnevolotskaya nisin with heights of
150180 m [
In more detail this issue will be considered later. 4.
For damage assessment, as well as for comparative assessment of external and internal exposure doses, we will consider the most dangerous accident. These data additionally give an idea of the situation around the Kalinin and Rostov NPPs.
The calculation will be made by the formula (1). As can be seen from the formula, we will need the data obtained earlier in the calculation of doses using formula (3) and presented in Table 1 and 2 [7].
Immediately, we note that the damage for Kalinin NPP, presented in [5], is significantly higher than for Rostov [4], which partially confirms our formula and conclusions made on the basis of a comparative assessment for doses of external and internal exposure.
First, perform the calculations for the Rostov NPP.
L (for the Rostov NPP at a distance of 10, 30 and 100 km from the NPP):
L(10) = 0,04 million rubles L(30) = 0,84 million rubles L(100) = 5,87 million rubles
L (for Kalinin NPP at a distance of 10, 30 and 100 km from the NPP):
L(10) = 7,66 million rubles L(30) = 100,14 million rubles L(100) = 531, 59 million rubles
Again, we get an excess of the Kalinin NPP. This excess has a logical explanation. The population is one of the main indicators for damage. Since the main costs fall on the people and property that these people possess. Of course, errors are permissible, since For the Kalinin and Rostov nuclear power plants, calculations were made taking into account the most probable wind direction, but these errors do not change the overall Figure. 5.
Calculation of damage to the population in the ring segment
of rumba, as a result of exposure to radioactive substances, was
carried out according to formula (1) [
The calculation of the annual effective radiation dose of the
population in the ring segment of rumba, taking into account the
wind rose, was carried out according to the formula (3) [
In [
For power units with RBMK-1000 type reactors (Kursk and Smolensk NPP) - Table. 3-14, fig. 1-6.
Table 3. Indicators of radiation risk for the population from accidents at the Kursk NPP Average individual Individual risk of death of Individual risk of the effective dose for the population (long-term population death rci, 1/year population Ei, Sv effects) rc, (for 1 accident) (considering EA frequency) 2.510-4 1.2510-5 8.7510-13 Southeast
South Southwest
Figure 2 shows a graphical representation of the results of
calculating the annual effective doses of exposure of one person
and the entire population living in the ring segment of rumba,
taking into account the wind rose, for Kursk NPP [
At present, external and internal exposure doses for Kalinin and Rostov NPPs have been considered. An assessment of material damage was conducted. A variant of the format of the atlas of risk assessments is proposed. Initial assumptions have been made regarding the discrepancy in the results obtained for both doses and damage.
The study was carried out within the framework of grant 1907-00455 «Development of models, algorithms and software for solving the problems of safety and risk assessment at nuclear power plants during beyond design basis accidents with the release of sources of thermal neutrons with low flux density».