Nuclear waste

Question 1

Three management techniques

Answer 1

High level = concrete and contain

Intermediate level = dilute and disperse

Low level = delay and decay

Question 2

Why doesn’t delay and decay work with high level waste

Answer 2

half life is too long - can take thousands of years to decay

Question 3

3 points on high level waste

Answer 3

• used fuel
• 3% volume 95% radioactivity
• heavy and long lived
• special shielding and handling

Question 4

3 points on intermediate level waste

Answer 4

• reactor components
• 7% volume 4% radioactivity
• short lived mostly

Question 5

3 points on low level waste

Answer 5

• hospitals, labs
• small amounts of short lived isotopes
• 90% of all waste 1% radioactivity

Question 6

Nuclear fission produces lots of energy and creates less greenhouse gases than burning fossil fuels. The waste products usually have a larger percentage of neutrons than nuclei of a smaller atomic number making them unstable and radioactive. The products can be used for practical applications such as tracers in medical diagnosis

Answer 6

However they may still be highly radioactive and so their handling and storage needs great care. When the material is removed from the reactor it is initially very hot so is placed in cooling ponds until the temperature falls to a safe level. This is alone remotely, like the handling of fuel, to limit the radiation workers are exposed to. The radioactive waste is thee stored in sealed containers until its activity has fallen enough

Question 7

Radioactive waste is categorised as high, intermediate or low level according to ________.
High level waste (e.g. spent fuel rods) must be removed by ______ and stored underwater in _______ for up to a year because they continue to release heat due to _____. The unused uranium and plutonium are removed and stored in ______. The rest of the material is radioactive waste and is stored in sealed containers in _______. Such waste must be stored safely for centuries as isotopes are ______.

Answer 7

its activity
remote control
cooling ponds
decay
sealed containers
deep trenches
long-lived

Question 8

Intermediate-level waste such as low activity radioactive materials are

Answer 8

sealed in drums encased in concrete, and stored in specialised buildings constructed with walls of reinforced concrete.

Question 9

Low-level waste such as laboratory equipment are

Answer 9

sealed in metal drums and buried in large trenches

Question 10

Most high-level radioactive waste is from

Answer 10

nuclear power stations or hospitals