Nuclear reactors only have a finite lifetime due to the problem of neutron irradiation of reactor components.
All power stations have a limited lifetime. In all cases, metals corrode and parts wear out. Many reactors around the world, which are approaching the end of their originally planned life, have actually received life extensions, reflecting their robustness. Generation III+ reactors are designed to last 40-60 years (and will then probably be extended further).
Decommissioning nuclear facilities is notoriously difficult.
There is nothing particularly unique about dismantling a nuclear power station except that greater care is taken to dispose of the materials properly than in non-nuclear industries. Most parts are pretty unremarkable and the metals can be sold for scrap. Only core materials, which have been subjected to neutron irradiation, are a major radioactive hazard. They are classed as intermediate level waste, requiring some limited shielding. They represent a strict minority of radwaste both in volume (the bulk of radwaste by volume is low level waste) and activity (by radioactivity, high level waste is the bulk). Disposing of it is far from a prohibitively large problem.
In some cases, the core is left standing for several decades to allow the activated metal to decay to insignificant levels. Whether this is done is dependent on the situation. If the site remains in use for other reactors etc, this may be more economical since handling and disposing of long decayed core materials is cheaper. The delay between shutdown and decommissioning will depend on the situation. In neither case is it technically or economically difficult.
The cost of this decommissioning represents a hidden charge that will have to be shouldered by the taxpayer.
Nuclear operators pay in advance for the decommissioning costs. In some cases, the funds are set aside at first construction, but more commonly, a fund is raised throughout the lifetime of the reactor. A small portion of the price of the electricity is dedicated to funding decommissioning in a similar way to the funding of spent fuel handling. It is not paid by the taxpayer, but by the ratepayer as one would expect.
The Nuclear Decommissioning Authority in the UK has pegged decommissioning at £66 billion.
This figure is frequently misunderstood. This is the total cost, according to NDA estimates, for the total clean-up of all British nuclear legacy sites and return to Greenfield status. This includes not only the Magnox reactors and other fuel cycle facilities, but also military establishments like Windscale and UKAEA facilities such as Dounreay. Sellafield represents the bulk of the decommissioning, most of it due to its military heritage rather than the commercial THORP and MOX facilities currently operating there, with less than £8 billion going towards UKAEA and £12 billion towards to the Magnox fleet (Magnox reactors themselves involve over five times the decommissioning costs compared to LWRs due to the greater amount of irradiated material involved). The costs of decommissioning the Magnox fleet has been raised through the price of electricity in much the same way as described above. The same thing is being done for the future decommissioning of the Generation II reactors operated by British Energy.
But there is controversy over the NDA estimate. For one, the cost of decommissioning the Magnox reactors is twice earlier estimates without good reason. But more importantly, the NDA assumed a return of nuclear sites to Greenfield status. In other words, they are assuming the complete cessation of all nuclear activities, including medical. If current nuclear sites continue to be used productively, the cost drops. It is a great irony that those wishing the cessation of all nuclear activities use the NDA estimate to justify it. In fact, it is their plan, which causes the inflated figures in the first place.
The significance of this oft-quoted figure in the British arena is the use by the opposition to argue against renewal of the reactor fleet. They argue that this figure would be repeated and burden the taxpayer as a "subsidy" if the fleet was to be renewed. Liberal Democrat leader Sir Menzies Campbell said it would be a "stealth tax". But he forgets two important facts:
- Most of this cost is for legacy clean-up, not the commercial reactor fleet, which would be replaced. And particularly given the way graphite moderated, gas-cooled reactors dominant the British market, the equivalent costs for Generation III+ PWRs will be much, much less.
- This money is not being sucked out of taxpayers' pockets by large pumps in the ceiling in the way Mayor Quimby extracted the money from the citizens of Springfield to cover the damage caused by the Roofi concert. The funds to pay for decommissioning commercial reactors is raised in the openly stated price of the electricity generated. There is no need for a stealth tax.