Triest, Italy - December 2008
Giuseppe NACCI (M.D.)
Specialized in Nuclear Medicine
Fallout caused by an accident at a nuclear power station of Krsko (Slovenia)
Introducing a new colorimetric scale
(BLACK, GREY, RED, ORANGE, YELLOW and WHITE Zones
to evaluate the effects of radioactive Fallout on civilian populations)
Krsko: nuclear risks at a distance of 130 km from Trieste (Italy).
The entire region of Friuli-Venezia Giulia could be contaminated
within 3 hours…
A study conducted 20 years ago estimated
the amount of damage that Trieste and Friuli-Venezia Giulia
would suffer in the case of an accident at the reactor
and a leakage of radioactive materials
What would happen if the false alarm of 4th June 2008 were a concrete risk?
With a weak wind of 6 km/h coming from the east, Italy would not be reached by a Fallout from Krsko, besides a weak temporary radioactivity known as White Fallout (0.1 RAD/h), which is not shown on the slides to improve readability (Figure 6-A).
But a steady wind of 15 km/h coming from the east would suffice to let radioactive contamination affect the whole area from Trieste up to Tarvisio, reaching almost Tolmezzo, thus contaminating the greater part of the Friuli-Venezia Giulia within 8-10 hours – Udine included. This scenario would correspond to a Yellow Fallout (0.5 RAD/h), as Krsko is located only 130 km from the Italian border as the crow flies (Figure 6-B). During the following four days the radiation dose absorbed by an individual would range from 10 to 50 RAD, about half of which during the first day.
With a steady wind of 30 km/h, radioactive contamination would affect the entire region of Friuli-Venezia Giulia and a small part of Veneto (Treviso and Venice), showing a level of contamination again corresponding to a Yellow Fallout (0.5 RAD/h), except for Trieste which would have a higher level of radioactivity, i.e. an Orange Fallout (1 RAD/h) (Figure 6-C).
With a steady wind of 50 km/h coming from the east, radioactive contamination would again affect the whole area from Trieste up to Tarvisio, excluding Tolmezzo but contaminating more than half of the region within 4 hours, Udine included. This scenario would correspond to an Orange Fallout (1 RAD/h) (Figure 6-D). In this area, during the 4 days following the accident the radiation dose absorbed by an individual would range from 20 to 100 RAD, about half of which during the first day. The contamination area, called Yellow Zone, would extend as far as Bologna, where the radiation dose absorbed by an individual would also range from 10 to 50 RAD, about half of which during the first day.
With a steady wind of 70 km/h coming from the east, radioactive contamination from Orange Fallout (1 RAD/h) would affect almost the entire region of Friuli-Venezia Giulia, except for Pordenone and the Veneto region, where there would be a Yellow Fallout (0.5 RAD/h) within the first 12 hours following the accident, together with a wide part of Emilia Romagna and Trentino-Alto Adige (Figure 6-E).
With a steady wind of 100 km/h coming from the east, the Orange Fallout Zone would include Pordenone, Treviso and Venice, while the Yellow Fallout Zone would affect even greater areas of Emilia Romagna and Trentino-Alto Adige regions (Figure 6-F).
In the southern part of Austria (Klagenfurt, Graz), with winds coming from the south and faster than 70 km/h, there would mostly be a contamination from Red Fallout, i.e. with radiation doses absorbed by the population during the first four days ranging from 100 to 500 RAD.
Slovenia and Croatia – instead – would be affected by severe consequences caused by Black Fallout and Grey Fallout. The former would cause levels of contamination for each inhabitant ranging from 1,000 to 5,000 RAD within the first four days, half of which absorbed during the first day; the latter would instead cause lower but still lethal levels of radioactivity, with doses ranging from 200 to 1,000 RAD in the first four days.
Fortunately, in Krsko there was only a leak of water from the cooling plant inside the reactor, which did not cause any radioactive leakage in the environment. That is why the emergency was called off: thanks to the timeliness of the turn-off procedure the nuclear power plant was safe again within a few hours. In short, there were no risks for the population. But the episode revives the fear of a new Chernobyl, close to Croatian, Hungarian and Austrian borders.
Such an assumption was made about twenty years ago by the author of this paper, when he was a young student of medicine, after three years from the disaster occurred in the Soviet Union. The title of the study was: Krsko: nuclear radiations and civil protection in Trieste.
He explained in the study: Let us suppose that the most serious accident that could happen in a water reactor – i.e. the total leak of the liquid used to cool the uranium core – occurred at the nuclear power station in Krsko. In this unlucky case, the core would get overheated, molten materials would enter into contact with turbine water and transform it into steam. This would cause the opening of the control container and consequently the leakage of radioactive materials. Let us also suppose that a third of all radioactive cores present in the reactor were released into the air because of this explosion.
According to studies dating back more than 8 years,  in this kind of accident the radioactivity of leaked material would be about 1.5 billion curie and the radioactive cloud – with a wind of 24 km/h – would have an extent of tough contamination (Black Fallout) over a radius of 68 km from the Krsko nuclear power station. At this point it is possible to evaluate the different levels of radioactive contamination that would affect Trieste and the Friuli-Venezia Giulia region...”
However, medical consequences should also be analysed in detail.
There are two types of radiations: alpha or betaradiations – which are dangerous only if radioactive cores producing them are inhaled or absorbed by foods and water – and gamma radiations, which are emitted by radioactive cores and do not need to be absorbed by the body to kill.
Furthermore, the author noted: The dose of gamma radiations that can affect an individual is expressed in REM, a unit of measurement that can be considered equivalent to RAD.
Gamma radiations of 500 RAD – if absorbed in few days – would also cause the death due to damaged bone marrow in half the population within a month, because of the destruction of white blood corpuscles and platelets; gamma radiations of 200 RAD would lead to the death of only a tenth of exposed individuals but all surviving people could no longer conceive children (permanent sterility).
As regards the possibility of falling ill with cancer during the following years – the author warned – nobody could exclude it.
In the Yellow Zone, during the 4 days following the accident, the radiation dose absorbed by an individual would range from 10 to 50 RAD, about half of which during the first day.
Other about 50-70 RAD during the following 30 days.
In the Orange Zone, during the 4 days following the accident, the radiation dose absorbed by an individual would range from 20 to 100 RAD, about half of which during the first day.
Other about 100-150 RAD during the following 30 days.
In the Red Zone, during the 4 days following the accident, the radiation dose absorbed by the individual would range from 100 to 500 RAD, about half of which during the first day.
Other about 500-700 RAD during the following month.
In the Grey Zone, during the 4 days following the accident, the radiation dose absorbed by an individual would range from 200 to 1,000 RAD, about half of which during the first day.
In the Black Zone, during the 4 days following the accident, the radiation dose absorbed by an individual would range from 1,000 to 5,000 RAD, about half of which during the first day.
The outlook is not reassuring – and it was already supposed twenty years ago.
Nowadays the paper – which was presented for the first time at the Circolo Ufficiali di Presidio (Garrison Officers’ Club) in Trieste, - in 27th January 1989 – is again alarmingly topical, given recent news alleging that the Krsko nuclear power station was built next to a dangerous seismic fault. It cannot be excluded that a new earthquake, such as those which razed Ljubljana to the ground in 1511 and 1895, would damage the base of the nuclear power station and lead to a leak of its cooling water.
The effects of Fallout on man can be summarized thus:
1) acute ray syndrome: death within a few weeks or even days; from a clinical point of view the white blood cells, the red blood cells and the platelets in the bone marrow may stop producing completely (“Bone Marrow Death”); the gastro-intestinal system is seriously damaged (“Intestine Death”). In these two cases death occurs within a few weeks because of infection or hemorrhages. In the case of even higher doses of radiation, death occurs within a few days through the “Collapse of the Central Nervous System”.
2. Delayed ray syndrome: death occurs within 6-8 months, because of serious damage to the respiratory system.
3. Leukemia or cancers: death occurs over the succeeding years among a high percentage of the survivors.
4. Genetic mutations: there is a high rate of miscarriages and deformed babies.
The amount of radiation absorbed because of local Fallout, expressed in REM or centi-Sievert (1 REM = 1 centi-Sievert) and referring to a certain period of time in which the civil population is exposed to this Fallout, is thought to be very high near the nuclear power station (atomic reactor) and less and less as you move away from the city where the nuclear power station (atomic reactor) occurred. This Fallout is thought to be extensive when there is an strong winds.
This research has been so divided:
1. Units of radiation measurement: Roentgen, RAD, REM, Sievert, Gray, Curie and Becquerel.
2. The biological effects of the different amounts of radiation absorbed, expressed in REM.
3. The different levels of radioactive contamination classified on the proposal of the Author, that is: the Black Zone (the most contaminated area) the Gray Zone, the Red Zone, the Orange Zone, the Yellow Zone and the White Zone (the least contaminated area). Examples of contamination following nuclear accident of atomic reactor of power station of Krsko (Slovenia) and with different wind speeds, with practical explanations on the use of a Nomogram to predict Fallout.
4. The different levels of radioactive contamination classified on the proposal of the Author, that is: the Black Zone (the most contaminated area) the Gray Zone, the Red Zone, the Orange Zone, the Yellow Zone and the White Zone (the least contaminated area). Examples of contamination following nuclear explosions of atomic bomb (of different power) in Italian city of Milano, with equal wind speeds, with practical explanations on the use of a Nomogram to predict Fallout.
5. Residual radioactivity from Caesium 137, Strontium 90, Iodine 131, Plutonium and Uranium.
6. Fallout caused by an accident at a nuclear power station: the disaster of Chernobyl.
7. The Testament of Chernobyl.
8. From the atomic Bomb to genetic Bomb: the Threat of Genetically Modified Organism.
of nuclear bomb or Chernobyl-incident of a nuclear power station)
Figs. 2, 3 and fig. 4
Estimate of the total gamma dose absorbed (x-axis),
according to the haematic-lymphocyte count (y-axis)
Curve showing the appearance of leukemia and solid cancers over time,
after a single exposure to radiation (1 REM)
of sufficient dose to cause a tumor
Two decay curves: from atomic explosion (nuclear bomb)
and from Chernobyl-incident of a nuclear power station
Fallouts from a Chernobyl-incident (hypothetical)
of nuclear power station of Krsko (Slovenia)
Fallout from atomic explosion of 1.000 kiloton after 1, 6 and 18 hours
The Haaland nomogram