Benefits And Drawbacks Of Using Radioactuve Materials

Question 1

Who and how was radioactivity discovered

Answer 1

Henri becquerel was investigating how uranium emits light after being exposed to the sun. On a cloudy day, he put some uranium into a draw with a photographic plate and when he opened the drawer, the plate had unexpectedly become exposed, he realised that radiation emitted from uranium didn’t need and external energy source. This is radioactivity

Question 2

How can radiation cause cancer

Answer 2

They ionises celles and change the DNA in its nucleus. This is called a mutation which could cause it to rapidly grow and become cancer.

Question 3

What safety measures are used when handling and storing radioactive materials

Answer 3

They are kept in lead lined boxes as the radiation is stopped by it. They are also handled with tongs to keep them away from the handler. We also don’t point them at people and in some cases, special suits are worn.

Question 4

What is HLW and give an example of it

Answer 4

HLW is High level waste and is very radioactive waste material such as waste products in nuclear fission. They can produce large amounts of ionising radiation for over 50 years.

Question 5

What is ILW and an example

Answer 5

ILW is intermediate level waste and is less radiative than HLW but remains moderately radioactive from 10s of thousands of years. HLW becomes ILW after about 50 years. Another example of ILW is the metal containers that stored the uranium fuel.

Question 6

What is LLW and example

Answer 6

LLW is low level waste and is slightly radioactive but like ILW it stays like this for tens of thousands of years. It includes clothing and cleaning materials used in power stations.

Question 7

Why are hospitals a source of LLW

Answer 7

Hospitals are sources of LLW as they use radioactive isotopes in treatment such as radiotherapy for cancer patients.

Question 8

How is HLW stored

Answer 8

HLW is stored in metal and concrete containers to absorb the radiation. These containers are sealed in glass to make sure no radioactive material escapes. These are put into containers and stored until it becomes ILW

Question 9

What is ILW stored in

Answer 9

It is stored in steel and concrete containers

Question 10

How is LLW stored

Answer 10

It is compacted and buried in special landfill sites and can’t be put into normal ones as there is a risk of radioactive material leaking into water or soil.

Question 11

What is are advantages to nuclear power

Answer 11

It doesn’t create any CO2 so it doesn’t contribute to g tonal warming. It also doesn’t need much fuel so is very efficient

Question 12

What are disadvantages to nuclear power

Answer 12

It is very expensive to set up the power plant
The production of fuel rods uses lots of energy which may have been sourced from fossil fuels
It is very expensive to store nuclear waste as it can’t be leaked into the environment and needs to be stored for a very long time
If there is a meltdown then radioactive material may be spread over a very large area.

Question 13

What is nuclear decay and how is it measured

Answer 13

Nuclear materials decay to become more stable. The number of decays per second is measured in becquerels (Bq) 1 Bq is one decay per second.

Question 14

What is half life

Answer 14

The time it takes for half of a nuclear material to decay. This can be seconds or millions of years. It is the same for however much of an isotope there is.

Question 15

How is the radioactivity measured

Answer 15

Measured by a Geiger muller tube (GM) which clicks every time ionising radiation is detected

Question 16

What is the count rate and what is it used for

Answer 16

The count rate is the number of clicks a GM tube makes every second. This can be used to work out the half life of a material from a graph

Question 17

What is a half life of a material that clicks 600 counts per second at 5 minutes and 300 times at 12 minutes

Answer 17

12-5 = 7 so half life is 7 minutes

Question 18

What is background radiation

Answer 18

Low level ionising radiation from the environment

Question 19

What 6 things contribute back ground radiation and what percentage do they contribute

Answer 19

Radon gas 50%
Buildings and ground 14%
Cosmic rays 10%
Medical 14%
Nuclear power 0.3%
Food and drink 11.5%
Other 0.2%

Question 20

Where does radon come from

Answer 20

Uranium is found in rocks. When this uranium decays, it creates isotopes including radon fas

Question 21

How are gamma rays used to help detect cancer

Answer 21

A tracer solution containing a source of gamma rays is injected into the body. This builds up in areas of abnormal activity such as where there is cancer. The gamma rays penetrate through the body and are detected by a gamma camera. This shows where there may be cancer

Question 22

Why can only gamma rays be used to detect cancer

Answer 22

Alpha and beta particles are absorbed by the body so won’t be detected

Question 23

How can radiotherapy cure cancer

Answer 23

Gamma rays can be aimed towards the cancer and fired in beams, killing the cancer

Question 24

Uses of radiation (4)

Answer 24

Diagnosing cancer
Treating cancer
Sterilising equipment such as plastic as it kills the microorganisms (they are irradiated)
Irradiating food

Question 25

Why is some food irradiated

Answer 25

To kill bacteria and organisms on the food. This can slow down its decomposition and make it safer to eat. Foods that are allowed to be irradiated include potatoes, fruit, vegetables, fish and poultry…..

Question 26

What is a main use of alpha particles and how does it work

Answer 26

Smoke detectors. They contain 2 electrically charged plates, negative and positive and a source of alpha particles (americium-241). The alpha particles ionise the air between the plates which gives out electrons and ions. These are attracted to the oppositely charged plate creating a small circuit. This is always happening unless something absorbs the alpha particles, in which the circuit breaks. When there fire, the smoke absorbs the alpha particles and breaks the circuit. This triggers an alarm.

Question 27

What is a main use of beta particles and how does it work

Answer 27

When paper is rolled, it needs to be the correct thickness. To do this a beta source is put under the paper and a detector is above it. When the paper is too thin, the detector detects more beta particles so it tells the computer to reduce pressure on the rollers, if it is too thick, the opposite happens.

Question 28

What is an environmental use of gamma rays and how does it work

Answer 28

Gamma rays can be used to detect leaks in water pipes. A tracer is added to the water which flows through the pipe. A GM tube is moved along the ground above the tube and detects the gamma rays. Where there is a leak, there are more gamma rays and the GM tube detects this.

Question 29

Why are alpha particles ideal for smoke alarms
Why are beta particles ideal for measuring e thickness of paper
Why are gamma rays ideal for finding leaks in pipes

Answer 29

Alpha particles as they ionise particles fast so lots of electrons are released so the currant stays strong and they can’t penetrate the casing of the alarm so aren’t harmful to anything

Beta particles as the can penetrate enough through paper but at the same time, little enough so not all gets through which can be detected whereas if gamma rays were used, all would get through and if alpha were used, none would get through

Gamma rays as they aren’t as harmful as alpha and beta and can penetrate far so they can be detected through the ground.