Inherently safe nuclear power

Spurred on by worries about nuclear accidents, engineers have devised
many new reactors with improved safety features. The GT-MHR power
plant, for example, is claimed to be inherently safe; and, moreover it has
a higher efficiency of conversion of heat to electricity than conventional
nuclear plants [].


Two widely-cited defects of nuclear power are construction costs, and
waste. Let’s examine some aspects of these issues.

Building a nuclear power station requires huge amounts of con-
crete and steel, materials whose creation involves huge CO2

The steel and concrete in a 1 GW nuclear power station have a carbon
footprint of roughly 300 000 t CO2.

Spreading this “huge” number over a 25-year reactor life we can express
this contribution to the carbon intensity in the standard units (g CO2
per kWh(e)),

carbon intensity
associated with construction
 =  300× 109 g
106 kW(e) × 220 000 h
 =  1.4 g/kWh(e),

which is much smaller than the fossil-fuel benchmark of 400 g CO2/kWh(e).
The IPCC estimates that the total carbon intensity of nuclear power (in-
cluding construction, fuel processing, and decommissioning) is less than
40 g CO2/kWh(e) (Sims et al., 2007).

Please don’t get me wrong: I’m not trying to be pro-nuclear. I’m just

Isn’t the waste from nuclear reactors a huge problem?

As we noted in the opening of this chapter, the volume of waste from
nuclear reactors is relatively small. Whereas the ash from ten coal-fired
power stations would have a mass of four million tons per year (having a
volume of roughly 40 litres per person per year), the nuclear waste from
Britain’s ten nuclear power stations has a volume of just 0.84 litres per
person per year – think of that as a bottle of wine per person per year
(figure 24.13).

Most of this waste is low-level waste. 7% is intermediate-level waste,
and just 3% of it – 25 ml per year – is high-level waste.

The high-level waste is the really nasty stuff. It’s conventional to keep
the high-level waste at the reactor for its first 40 years. It is stored in pools
of water and cooled. After 40 years, the level of radioactivity has dropped
1000-fold. The level of radioactivity continues to fall; after 1000 years,E the

Figure 24.12. Chernobyl power plant (top), and the abandoned town of Prypiat, which used to serve it (bottom). Photos by Nik Stanbridge.