Nuclear Technology: Benefits and Risks

0:00Nuclear technology has big benefits and real risks. Let's weigh them up.

0:06We will look at four uses: power, medicine, food and dating.

0:13Nuclear power stations use fission, the splitting of uranium nuclei, to make lots of electricity with very little carbon dioxide.

0:22But the used fuel is radioactive: its unstable nuclei give out radiation. It must be stored safely for thousands of years.

0:32That radiation can damage or kill living cells.

0:36Accidents are rare but can be serious, as at Chernobyl in 1986 and Fukushima in 2011.

0:44In medicine, a tracer called technetium ninety-nine M is injected, and a gamma camera detects its rays to make a scan.

0:53Its half-life, the time for half its nuclei to decay, is only about 6 hours.

0:59Gamma rays from cobalt 60 are aimed at tumours to kill cancer cells.

1:05But the rays can harm healthy cells too, so doses are carefully limited.

1:10Food irradiation uses radiation, such as gamma rays, to kill bacteria so food keeps longer.

1:18A common myth is that irradiated food becomes radioactive.

1:23It does not, because no radioactive atoms get into the food.

1:27Radioactive dating uses carbon 14 to find the age of old remains.

1:33After death, its carbon 14 halves about every 5,730 years, so what is left shows the age.

1:42It adds no radiation: it only measures what is already there.

1:47Nuclear technology has big benefits, but its risks must be carefully managed.