There are seven main issues that cause debate about reprocessing:
1. Proliferation risk of recycled plutonium
Reprocessing releases plutonium in a separated form, which leads to nuclear proliferation concerns. Unreprocessed fuel also contains plutonium, but it is intimately mixed with intensely radioactive fission products (the so-called “radiation barrier”), making it extremely difficult to access. A potential proliferator would need to build their own reprocessing plant — a specialised activity that is difficult to conceal. Political concerns about proliferation led the Carter administration in the late 1970s to ban civilian reprocessing in the USA. The UK and France continued reprocessing despite some international pressure to discontinue.
Key Point: The IAEA’s International Fuel Cycle Evaluation (INFCE) project concluded that the cost difference between once-through and recycling was small, with once-through being approximately 10% cheaper. However, note that the potential of reactor-grade plutonium as a material for nuclear weapons is unproven — its isotopic composition differs greatly from weapons-grade plutonium.
2. Cost of reprocessing vs fresh uranium
Irradiated fuel contains very high activities of fission products, creating very substantial radiological problems during processing. Solving these problems is expensive, and reprocessing may not be cost-effective compared with fuel sourced from freshly mined uranium, especially during periods of low uranium prices as in the 1990s.
3. Surplus plutonium inventory
There is now an excess of plutonium worldwide. Up to 1995, approximately 970 tonnes of plutonium had been generated from 180,000 tonnes of irradiated fuel, of which 185 tonnes had been separated and only 50 tonnes recycled. It is projected that through the use of MOX fuels, the Pu inventory will level out at 135—140 tonnes. Disposing of unwanted weapons fissile material is proving expensive; the USA declared approximately 50 tonnes of unwanted weapons plutonium, with Russia having even greater amounts.
4. Capital cost
Reprocessing plant is capital-intensive and takes a long time to build. THORP cost in excess of GBP 1,000 million. The long construction timescale makes building plant risky unless the future market for fissile fuel can be predicted with confidence.
5. Transport of irradiated fuel
With a small number of suitable plants worldwide, companies offering recycling facilities market themselves globally. Transport of nuclear fuel either by sea or across land borders excites activity by anti-nuclear pressure groups and raises safety and security concerns.
6. Environmental discharges
In addition to plutonium proliferation concerns, opponents of reprocessing point out that the procedure gives rise to radiation doses to workers and that discharges of liquid and gaseous wastes cause public and environmental exposure. The international nature of such exposure leads to diplomatic tensions, as governments of third-party states (such as Ireland, in connection with Sellafield) see their populations gaining no benefit from the reprocessing arrangements.
7. Public opinion
The fortunes of nuclear reprocessing in terms of public opinion are linked to those of the nuclear industry in general.