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 [gt-mhr.ga.com].



Mythconceptions

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

pollution.



The steel and concrete in a 1 GW nuclear power station have a carbon

footprint of roughly 300 000 t CO 2 .



Spreading this “huge” number over a 25-year reactor life we can express

this contribution to the carbon intensity in the standard units (g CO 2

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 CO 2 /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 CO 2 /kWh(e) (Sims et al., 2007).



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

pro-arithmetic.



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

