For some atoms are unstable
Some ratios in the nucleus of protons to neutrons make a nucleus stable or unstable , the graph shows the band where they are stable nuclei .
Ionizing radiation
Are streams of photons (electromagnetic radiation) or particles c on energy to break bonds and form ion chemical releasing electrons from atoms. Examples of these radiations are X-rays, gamma, beta or flow of particles such as neutrons and alpha particles
Decay rate
The speed of transformation of an unstable nucleus with emission of ionizing radiation, also known as an activity and is measured in disintegrations per second or Becquerel
Bq = 1 dis / sec
Average life
Is the time required for the initial activity of a radioisotope becomes half
Absorbed dose (D)
Is the energy imparted to matter , when ionizing radiation interacts with it , the unit is the Gray
Dose equivalent (H)
To assess the biological effects of a given radiation absorbed dose is modified by multiplying by the weighting factors of radiation, Wr depending on the type and energy of radiation
H = D * Wr
Effective dose (E)
Whereas each organ tissue has a different sensibildad to radiation is that the effective dose is defined as the sum of the equivalent dose in each tissue multiplied by a weighting factor for Tissue Wt
The table shows these factors are
Biological effects of radiation
Ionizing radiation affects the body when a human being produces ionization and other changes that can produce some effects that are visible and have a umbtral dose value below which no damage, these are the non-stochastic effects.
Stochastic effects in Cambuí carcinogenesis and has produced some threshold dose, are long latency effects, ie it can mafifestarse after a few years.
Committed equivalent dose
When a radioisotope enters the body through inhalation, ingestion or through the skin, internal organ remains in any longer due to slower metabolism, this is called the critical organ.
The radioisotope has a physical decay (disintegrations) and biological decay (elimination).
In these cases, use the committed equivalent dose is defined as the integral over a period of time
Radiation Protection
Basic criteria include:
Justification of the practice
All Exhibition of ionizing radiation should be justified, ie the benefit that exceeds obiene possible detriment to the individual or society
Optimization
The principle ALARA (As Low as Reasonable Achiable) as low as reasonably do , s and logara a single dose, the number of people exposed and the likelihood of receiving exposures as low as possible
Dose-limiting
For people whose ocupacón be exposed to ionizing radiation 'can receive a maximum dose of 20 mSv
For people who are occupationally expuestros, ie members of the public may DHW circulation up to 1 mSv per year to avoid any unacceptable risk
Annual limit of incorporation
When a radioisotope enters the body (can be swallowed. Inhalation or through skin)
produces an internal dose, as the limit is 20 mSv, then called the ativity ALI maximum annual intake to produce this dose.
Levels of intervention in a radiological emergency
To implement the measures for a radioactive release due to an accident involving a radioactive or nuclear unstalación apliocan intervention levels
Some ratios in the nucleus of protons to neutrons make a nucleus stable or unstable , the graph shows the band where they are stable nuclei .
Ionizing radiation
Are streams of photons (electromagnetic radiation) or particles c on energy to break bonds and form ion chemical releasing electrons from atoms. Examples of these radiations are X-rays, gamma, beta or flow of particles such as neutrons and alpha particles
Decay rate
The speed of transformation of an unstable nucleus with emission of ionizing radiation, also known as an activity and is measured in disintegrations per second or Becquerel
Bq = 1 dis / sec
Average life
Is the time required for the initial activity of a radioisotope becomes half
Absorbed dose (D)
Is the energy imparted to matter , when ionizing radiation interacts with it , the unit is the Gray
Dose equivalent (H)
To assess the biological effects of a given radiation absorbed dose is modified by multiplying by the weighting factors of radiation, Wr depending on the type and energy of radiation
H = D * Wr
Effective dose (E)
Whereas each organ tissue has a different sensibildad to radiation is that the effective dose is defined as the sum of the equivalent dose in each tissue multiplied by a weighting factor for Tissue Wt
The table shows these factors are
FABRIC | w T |
0.20 | |
0.12 | |
0.12 | |
0.12 | |
0.12 | |
0.05 | |
0.05 | |
0.05 | |
0.05 | |
0.05 | |
0.01 | |
0.01 | |
Rest | 0.05 |
Biological effects of radiation
Ionizing radiation affects the body when a human being produces ionization and other changes that can produce some effects that are visible and have a umbtral dose value below which no damage, these are the non-stochastic effects.
Stochastic effects in Cambuí carcinogenesis and has produced some threshold dose, are long latency effects, ie it can mafifestarse after a few years.
Committed equivalent dose
When a radioisotope enters the body through inhalation, ingestion or through the skin, internal organ remains in any longer due to slower metabolism, this is called the critical organ.
The radioisotope has a physical decay (disintegrations) and biological decay (elimination).
In these cases, use the committed equivalent dose is defined as the integral over a period of time
Radiation Protection
Basic criteria include:
Justification of the practice
All Exhibition of ionizing radiation should be justified, ie the benefit that exceeds obiene possible detriment to the individual or society
Optimization
The principle ALARA (As Low as Reasonable Achiable) as low as reasonably do , s and logara a single dose, the number of people exposed and the likelihood of receiving exposures as low as possible
Dose-limiting
For people whose ocupacón be exposed to ionizing radiation 'can receive a maximum dose of 20 mSv
For people who are occupationally expuestros, ie members of the public may DHW circulation up to 1 mSv per year to avoid any unacceptable risk
Annual limit of incorporation
When a radioisotope enters the body (can be swallowed. Inhalation or through skin)
produces an internal dose, as the limit is 20 mSv, then called the ativity ALI maximum annual intake to produce this dose.
Levels of intervention in a radiological emergency
To implement the measures for a radioactive release due to an accident involving a radioactive or nuclear unstalación apliocan intervention levels
Nuclear fission
It is a process in which a heavy nucleus and more instability is divided into two new smaller nuclei, it may occur spontaneously, without outside intervention, which is very rare, however this induced fission, which can be achieved by absorption of neutrons . Isotopes such as uranium 235 (U235) and plutonium 239 (Pu 239) are called fissile nuclei.
Fission cross section
Is the probability that fission occurs, in the case of uranium 235 is necessary that the neutrons are thermal energy is low so that this probability is high and this is the case of fission.
Nuclear plant
This is a facility where you get energy from the fission of nuclear fuel is usually enriched uranium , as opposed to a research reactor that are low power and for research and radioisotope production
Fukushima plants are called "Boiling Water Reactors" (boiling water reactors) BWR
The nuclear fuel boils water and creates steam, steam turbines will create electricity, after that steam is cooled and condensed and passed to be heated again for nuclear fuel.
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