0647126_DA545_nadeina_l_v_radioekologiya

4.Альфа-частицы действуют на организм на небольшом расстоянии от источника (0,05 миллиметра) и приводят к гибели клеток, через которые они проходят.

5.Вся их энергия полностью поглощается тканью в точечной области.

6.Поэтому в результате вдыхания этих частиц может появиться «дыра» в легких.

7.Известно, что риск возникновения рака легких при ингалировании нерастворимых соединений плутония в 2-3 раза выше, чем от растворимых, что можно интерпретировать как эффект «горячих частиц».

8.Наименьшая доза, при которой происходит канцерогенез, оценивается в 24000 Рад.

9.Сложность оценки поглощенных доз от «горячих частиц» для близлежащих клеток состоит в том, что «горячие частицы» перемещаются.

10.Например, легочная ткань старается вытолкнуть инородные частицы в горло, откуда они могут попасть в пищевод или лимфоузлы.

11.Клетки-макрофаги также перемещают частицы с места на место.

12.После аварии 06.04.1993 на радиохимическом производстве СХК в районе следа было установлено присутствие большого количества частиц микронного размера (10мкм) с мощностью дозы гамма-излучения более 24мР/ч.

13.По своим параметрам эти образования являются классическими «горячими частицами». Кроме бета-излучателей, в них находятся альфаизлучатели, такие как уран-235, плутоний-239, америций-241 и т.д., что может кратно увеличить данную расчетную дозу.

14.На сегодняшний день с помощью методики осколочной (f) радиографии достаточно четко откартирована зона максимального накопления микровключений делящихся элементов, образующих многолучевые “звезды» в верхнем горизонте почв.

15.Трагедия ликвидаторов последствий аварии на ЧАЭС заключается не только в том, что они получили высокие дозовые нагрузки от внешних факторов, а в том, что они подверглись массированному воздействию потока «горячих частиц».

16.Аналогичная ситуация может наблюдаться на урановорудных предприятиях. 17. В Томском регионе это один из возможных радиационно опасных факторов, обусловливающих высокие дозовые нагрузки на организм человека, устанавливаемые методами биодозиметрии.

(Л.П. Рихванов «Радиоактивные элементы в окружающей среде и проблемы радиоэкологии», Томск, 2009)

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UNIT IV

Radioactive Contamination and Radiation Exposure

Warming-up

Radiation Control Technician (RCT )

What does RCT do?

What role do radioactive control technicians play in ensuring the health and safety of employees working in radiation areas?

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Picture 1

Picture 2

Uranium mining

Look at the pictures 1 and 2 and answer the questions.

Do you know that uranium is the principle fuel for nuclear reactors and the main raw material for fission nuclear weapons?

Is uranium already radioactive when it is dug out of the ground?

What processes does uranium ore need to go through in order to concen-

trate the radioactivity by 2-3% to become nuclear reactor grade fuel, and by 80% to become weapons grade?

Do you know in what countries over half of the world’s uranium is?

Uranium is mined in 18 countries. Which ones?

What is the most prevalent isotope in uranium ore which has a half-life of

about 4.5 billion years; that is, only half the atoms will decay in that amount of time?

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Are uranium miners exposed to radioactive radon gas?

Why does uranium mining require a great deal of water?

Where is water which becomes radioactive waste placed?

Are evaporation ponds always adequately secured from leaking and flooding?

Do you know that contaminated rainwater can enter the soil and, eventually, the food chain, endangering health?

Do you know that …?

Glowing trucks, mutated animals, black rain, and the ghost town «Pripyat». Such haunting images are etched into the memories of Ukrainians who survived the 1986 nuclear explosion at the Chernobyl Atomic Energy Station. Residents were exposed to an unprecedented amount of radioactive contamination that posed serious consequences. Affecting individual health, the environment, the economy and political relationships, daily life for these people has been assaulted on multiple fronts. While some of the immediate dangers have transitioned into painful memories, many residents continue to live on contaminated land. Due to a lack of reliable information, many young families are defenseless against the invisible dangers of radioactive contamination.

Chernobyl Matryoshka

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The matryoshka doll (nesting Russian doll) is a well-known phenomenon. In this particular example, the doll is used to make a statement about the radioactive contamination from the Chernobyl disaster.

1. Read the text and do the tasks.

Radioactive Contamination and Radiation Exposure

Radioactive contamination and radiation exposure could occur if radioactive materials are released into the environment as the result of an accident, an event in nature, or an act of terrorism. Such a release could expose people and contaminate their surroundings and personal property.

Radioactive contamination occurs when radioactive material is deposited on or in an object or a person. Radioactive materials released into the environment can cause air, water, surfaces, soil, plants, buildings, people, or animals to become contaminated. A contaminated person has radioactive materials on or inside their body.

External contamination occurs when radioactive material, in the form of dust, powder, or liquid, comes into contact with a person's skin, hair, or clothing. In other words, the contact is external to a person's body. People who are externally contaminated can become internally contaminated if radioactive material gets into their bodies.

Internal contamination occurs when people swallow or breathe in radioactive materials, or when radioactive materials enter the body through an open wound or are absorbed through the skin. Some types of radioactive materials stay in the body and are deposited in different body organs. Other types are eliminated from the body in blood, sweat, urine, and feces.

Radioactive materials give off a form of energy that travels in waves or particles. This energy is called radiation. When a person is exposed to radiation, the energy penetrates the body. For example, when a person has an x-ray, he or she is exposed to radiation.

A person exposed to radiation is not necessarily contaminated with radioactive material. A person who has been exposed to radiation has had radioactive waves or particles penetrate the body, like having an x-ray. For a person to be contaminated, radioactive material must be on or inside of his or her body. A contaminated person is exposed to radiation released by the radioactive material on or inside the body. An uncontaminated person can be

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exposed by being too close to radioactive material or a contaminated person, place, or thing.

Radioactive materials could be released into the environment in the following ways:

A nuclear power plant accidentAn atomic bomb explosion

An accidental release from a medical or industrial deviceNuclear weapons testing

An intentional release of radioactive material as an act of terrorism

People who are externally contaminated with radioactive material can contaminate other people or surfaces that they touch. For example, people who have radioactive dust on their clothing may spread the radioactive dust when they sit in chairs or hug other people. People who are internally contaminated can expose people near them to radiation from the radioactive material inside their bodies. The body fluids (blood, sweat, urine) of an internally contaminated person can contain radioactive materials. Coming in contact with these body fluids can result in contamination and/or exposure.

People who are externally contaminated can spread the contamination by touching surfaces, sitting in a chair, or even walking through a house. Contaminants can easily fall from clothing and contaminate other surfaces. Homes can also become contaminated with radioactive materials in body fluids from internally contaminated people. Making sure that others do not come in contact with body fluids from a contaminated person will help prevent contamination of other people in the household.

Since radiation cannot be seen, smelled, felt, or tasted, people at the site of an incident will not know whether radioactive materials were involved. You can take the following steps to limit your contamination.

1. Get out of the immediate area quickly. Go inside the nearest safe building or to an area to which you are directed by law enforcement or health officials.

2. Remove the outer layer of your clothing. If radioactive material is on your clothes, getting it away from you will reduce the external contamination and decrease the risk of internal contamination. It will also reduce the length of time that you are exposed to radiation.

3. If possible, place the clothing in a plastic bag or leave it in an out-of- the-way area, such as the corner of a room. Keep people away from it to

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reduce their exposure to radiation. Keep cuts and abrasions covered when handling contaminated items to avoid getting radioactive material in them.

4.Wash all of the exposed parts of your body using lots of soap and lukewarm water to remove contamination. This process is called decontamination. Try to avoid spreading contamination to parts of the body that may not be contaminated, such as areas that were clothed.

5.After authorities determine that internal contamination may have occurred, you may be able to take medication to reduce the radioactive material in your body.

2.Answer the questions.

1)What is radioactive contamination?

2)What is external contamination?

3)What is internal contamination?

4)What is radiation exposure?

5)How does contamination differ from exposure?

6)How can exposure or contamination happen?

7)How is radioactive contamination spread?

8)How could your home become contaminated?

9)How can you limit contamination?

Grammar in Use

Forms of Infinitive

	Simple			Continuous	Perfect		Perfect Continuous
		Simultaneousness				Priority
Active		to	contami-	to be contami-	to	have	to have been con-
		nate		nating	contaminated		taminating
Passive		To	be	––––	To have been		–––––
		contaminated			contaminated

Complex Object

Noun (Common case)	}	+	Infinitive
Pronoun (Objective case)	}	+	Infinitive

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Complex Subject

Subject		+	Predicate	+	Infinitive
Noun (Common case)			(Passive Voice)
Pronoun (Nominative case)			or
			(Active Voice)
Note:	Active	Voice	to seem,	to appear – казаться;

to prove, to turn out – оказаться; to happen, to chance – случайно оказаться to be likely – вероятно; to be unlikely – маловероятно;

to be sure – несомненно; to be certain – обязательно

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Infinitive

At the		At the end		After the		After last,		After the
beginning		of the		subject		first,		predicate
of the		sentence				second
sentence

Function		Function		Function		Function		Function
of the		of the ad-		of the		of the		of the
subject		verbial		attribute		attribute		object
		modifier

Перевод:		Перевод:		Перевод:		Перевод:		Перевод:
существи-		для + сущ.		придаточ-		кто (что)		неопреде-
тельным		или		ным пред-		и глагол		ленной
или неоп-		чтобы +		ложением:		в том же		формой
ределен-		неопреде-		который		времени,		глагола
ной фор-		ленная		может,		что и
мой глаго-		форма		который		глагол гл.
ла		глагола		будет		предлож.
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2.1 Translate the following sentences paying attention to Subjective Infinitive Construction and Objective Infinitive Construction.

a)They enable scientists to measure extremely small amounts of chemical elements and isotopes present in released radioactive materials, thereby providing information about the process which formed them.

b)All the sample’s activity was found to be contained in the separated 54 hot particles.

c)The activity of the individual particles was estimated to be in the range 0.1 to 2.0 Bq of americium241 and the average diameter was about 20 micrometers.

d)The safety trials were conducted to investigate the behaviour of the core of nuclear devices under simulated faulty detonation conditions.

e)The activity of plutonium-239 was found to fall in the range 5 to 300 kBq, although a particle with a level of about one MBq was also found.

f)In addition to plutonium, the particles were found to contain other elements.

g)In general, any facility for the processing of nuclear material is known to release small, but detectable, amounts of radioactive and nonradioactive isotopes to the immediate environment.

2.2Say what grammar the following sentences illustrate.

1.People who are externally contaminated can become internally contaminated if radioactive material gets into their bodies.

2.Radioactive contamination and radiation exposure could occur if radioactive materials are released into the environment as the result of an accident, an event in nature, or an act of terrorism.

3.If radioactive material is on your clothes, getting it away from you will reduce the external contamination and decrease the risk of internal contamination.

4.Radioactive contamination occurs when radioactive material is deposited on or in an object or a person.

5.When a person is exposed to radiation, the energy penetrates the body.

6.Making sure that others do not come in contact with body fluids from a contaminated person will help prevent contamination of other people in the household.

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