How to be protected from radiation? Part 1. What is radiation and as far as it is dangerous?
(The Short guide for “teapots“) with
After the last explosions and emissions of radiation on “Fukushima“ the whole world the radio ecology question concerns. This article is intended to explain to the simple people wishing to learn what is radiation and as to be protected from it. If you are an expert with profile education - can not read further - I recommend to you to address better on professional forums. (Atominfo, for example) If you think that “for us leaders think, from above is more visible to them“ - too do not read. Turn on the TV, and you watch “Channel One“. It already showed that “the constant control is conducted“, “the radiation situation is normal“, having shown for greater persuasiveness close up an arrow of the SWITCHED-OFF Production Sharing Agreement radiometer - 68
Fig. 1. “Channel One“ lies about a radiation situation.
And further, probably, will show how the Kind Tsar-father at a steering wheel of the big red plane will strew over the Sea - Okiyan of the magic powder invented by his faithful boyars - alchemists Petrik and Gryzlov. And all overseas infection poluraspadtsya in a moment. And for the others - I will try to answer questions at the simplest level.
1. What happened on “Fukushima“? As a result of an earthquake and a tsunami the cooling system of reactors failed. And though reactors were stopped, in them the residual thermal emission proceeds. It led to formation of hydrogen and the subsequent explosions. By estimates of experts, at least in one, and most likely in several reactors there was a fusion of fuel weight and destruction of protective covers (both fuel cores, and the reactor case). Thus, intake of radioactive materials in environment began, and it will continue, at least several months, it will not be possible to cool fuel yet and to construct sarcophagi over reactors. Experts argue whether the Japanese accident of 10 or 40% from Chernobyl is equivalent, but it is clear that the number of radioactive emissions is huge. Fortunately for us, wind blows on the West so far, and the main part of emission dissipates over the sea, only partially touching Sakhalin, Kuriles and Kamchatka. But wind is changeable, and Earth round, and partially this rainfall already comes back to us from the West.
Fig. 2. A loop of radioactive fallout of “Fukushima“ (from the website Gismeteo. ru)
2. Whether “Fukushima“ at us can repeat? If detailed it is necessary to write separate article about it. If it is short - yes perhaps. Though lately huge efforts on increase of safety and physical protection of reactors are made, the Japanese accident showed vulnerability of stations to damages of auxiliary systems and the equipment. Yes, we have no tsunami and earthquakes, but slovenliness, corruption and terrorism can be even more terrible.
3. What is radiation? Radiation is a stream of particles - scale - quanta, a beta - particles (electrons), an alpha - particles (helium atomic nuclei), neutrons, kernels - the splinters of division which are formed during nuclear reactions. All these particles have very high energy - about several MEV (mega an electron - volt). For comparison it is possible to tell that energy of particles in chemical reactions (burning or the category of the battery) is million times less - about several an electron - volt.
4. By what radiation is dangerous? Passing through protective barriers and getting into a body of the person high-energy particles destroy fabrics, create active chemicals (free radicals), break the DNA genetic code. High doses of radiation for short term lead to sharp radiation sickness and death, small - to cancer diseases and mutations at posterity. Insidiousness of radiation is that it is not found our sense organs - only special devices.
5. How radiation is measured? Complicates a situation for the simple person a large number of units of measure of radiation: - The X-ray - a power unit of an exposition dose - rem (a biological equivalent of a X-ray) - the X-ray increased by “danger coefficient“ of this type of radiation (for alpha particles and neutrons - it is more) - is glad, Sievert - a power unit of the absorbed dose Yes experts will forgive me, but I will tell for general public that in the majority of practical cases it is possible to consider 1 X-ray =1ber =1rad 1 Sievert =100rentgen. Impurity of the district or products is measured respectively in Becquerels or Curie on sq.km or on kg. The becquerel is 1 radioactive decay of atom in a second. 1 Of Ki =3,7*10e10bk.
6. What dose of radiation is safe? Strictly speaking - any dose of radiation is dangerous. Most of physicians recognize “nonthreshold“ model, considering that the probability of oncological diseases increases even for small doses. However in life there is always a natural radiation background depending first of all on district geology. In the different countries, at different times and for different categories of the population different standards worked. As a first approximation, to within an order, it is possible to consider as a safe dose of 35 Rem (X-ray) for life. The dose gathered for a short time (days or hours) - conducts about 20 - 100 X-ray to sharp radiation sickness, it is higher than 500 X-ray - to death. For a natural radiation background usual norm - about 10 - 20 microroentgen an hour, value above 60 microroentgen an hour are considered raised. For the territory the impurity threshold usually is considered starting with 1 Ki/sq.km.
(Continuation of a subject - “As will be protected from radiation“ - follows)