Decommissioning of Nuclear Installations

At the occasion of the dinner-debate organised at the invitation of Foratom, Prof. Hennies, Member of the Managing Board of the Karlsruhe Research Centre in Germany, one of the EU’s largest nuclear establishment for R&D, which notably carried out the decommissioning process for the Niederaichbach NPP, presented the current decommissioning programme of several other nuclear installations such as a prototype fast reactor, two research reactors and a reprocessing facility.

Any industrial facility, such as nuclear power plants, has a definite operational lifetime at the end of which it needs to be taken out of service.

In the case of nuclear power plants and fuel cycle facilities, the process of decommissioning encompasses all measures following the final shutdown of a nuclear installation; the term also includes the conversion or modification of a plant for other uses or the complete disposal of facilities up to site restoration to green- field conditions. After removal of the nuclear fuel and the coolant from a plant, this objective basically can be achieved in two ways:

1. The safe enclosure is established first. In this approach, the activated and contaminated plant components, respectively, are protected by appropriate structural and technical measures so that any hazard to the environment can be excluded even over prolonged periods of time, at minimal monitoring expenditure. The period of closure may be a function of the decay characteristics of the activity inventory so enclosed. Once the activity level has decreased to a sufficient safe margin, simpler and less expensive demolition techniques may be used.

2. The second variant, on the other hand, implies immediate plant demolition, i.e. complete dismantling of all systems and installations of the controlled area is begun immediately after the post-operation phase.

The appropriate pathway is selected on the merits of each case and in the light of specific objectives and boundary conditions. At any rate, ensuring safety and the absence of environmental pollution takes precedence over the economic side of measures.

In Germany, where 16 reactors have been taken out of operation, one power reactor, the Niederaichbach nuclear power plant, was the first to be fully decommissioned and dismantled, and the site returned to green-field status.

In terms of costs calculation, the experience gained from decommissioning the Niederaichbach NPP confirmed that decommissioning costs are in the predicted range. When transferred to modern nuclear plants, they represent around 15% of the actual construction costs.
To provide for the financing of decommissioning, German utilities have created a fund which amounts to 54 Billion DMs. Similarly, in other European countries, its financing is included in the price of the KWh.

The experience acquired, in this particular case in Germany, illustrates that technology has now met satisfactory standards even if progress could still be achieved.
However, as demonstrated in the discussion that followed, number of questions remain such as :

Internalisation of all the external costs, including decommissioning

In order to establish the real cost of each competing energy, all the external costs should be reflected in the price of the KWh, as it is the case for nuclear energy. This would enable a fair commercial comparison.

Standardisation of decommissioning costs

It is impossible to establish a standard decommissioning cost. Indeed, it varies, in each country, according to circumstances and needs, such as e.g. the location of the nuclear installation. In this case, decommissioning is cheaper for installations located near the seashore as there is the possibility to ship the large pieces to disposal facilities.
Waste resulting from decommissioning

If the amount of waste and the degree of radioactivity is much smaller to those from the fuel cycle (95% of the waste from decommissioning is not radioactive), the question on how to categorise waste still remains.

Social acceptance

As Mr Forstršm – DG XII / European Commission – pointed out, decommissioning is a mature technology and R&D in this field is not a real necessity.

But while the feasibility of decommissioning is now technically demonstrated, it remains difficult to pass on this message to the general public.

MEP Giles Chichester, rapporteur on decommissioning, said that this was due to a lack of knowledge amongst politicians and the public who were not informed of the expertise gained in the field of decommissioning and believe that it still represented a problem.
Annex: Concise description of the decommissioning projects of the Karlsruhe Research Center (S-Division)