radioactivity of the high-level waste is about the same as that of uranium
ore.E Thus waste storage engineers need to make a plan to secure high-level
waste for about 1000 years.

Is this a difficult problem? 1000 years is certainly a long time compared
with the lifetimes of governments and countries! But the volumes are so
small, I feel nuclear waste is only a minor worry, compared with all the
other forms of waste we are inflicting on future generations. At 25 ml per
year, a lifetime’s worth of high-level nuclear waste would amount to less
than 2 litres. Even when we multiply by 60 million people, the lifetime vol-
ume of nuclear waste doesn’t sound unmanageable: 105 000 cubic metres.
That’s the same volume as 35 olympic swimming pools. If this waste were
put in a layer one metre deep, it would occupy just one tenth of a square
kilometre.

There are already plenty of places that are off-limits to humans. I may
not trespass in your garden. Nor should you in mine. We are neither of us
welcome in Balmoral. “Keep out” signs are everywhere. Downing Street,
Heathrow airport, military facilities, disused mines – they’re all off limits.
Is it impossible to imagine making another one-square-kilometre spot –
perhaps deep underground – off limits for 1000 years?

Compare this 25 ml per year per person of high-level nuclear waste
with the other traditional forms of waste we currently dump: municipal
waste – 517 kg per year per person; hazardous waste – 83 kg per year per
person.

People sometimes compare possible new nuclear waste with the nuclear
waste we already have to deal with, thanks to our existing old reactors.
Here are the numbers for the UK. The projected volume of “higher
activity wastes” up to 2120, following decommissioning of existing nuclear
facilities, is 478 000 m3. Of this volume, 2% (about 10 000 m3) will be the
high level waste (1290 m3) and spent fuel (8150 m3) that together contain
92% of the activity. Building 10 new nuclear reactors (10 GW) would add
another 31 900 m3 of spent fuel to this total. That’s the same volume as ten
swimming pools.

If we got lots and lots of power from nuclear fission or fusion,
wouldn’t this contribute to global warming, because of all the
extra energy being released into the environment?

That’s a fun question. And because we’ve carefully expressed everything
in this book in a single set of units, it’s quite easy to answer. First,
let’s recap the key numbers about global energy balance from p20: the average
solar power absorbed by atmosphere, land, and oceans is 238 W/m2;
doubling the atmospheric CO2 concentration would effectively increase the
net heating by 4 W/m2. This 1.7% increase in heating is believed to be bad
news for climate. Variations in solar power during the 11-year solar cycle
have a range of 0.25 W/m2. So now let’s assume that in 100 years or so, the
world population is 10 billion, and everyone is living at a European stan-

Figure 24.13. British nuclear waste, per person, per year, has a volume just a little larger than one wine bottle.