Decommissioning & decontamination

Italys shutdown strategy

3 December 2003

Since the 1987 decision to abandon nuclear power in Italy, the country’s decommissioning strategy has had to evolve with the changing social, industrial and political circumstances. By Luigi Noviello and Ivo Tripputi

The Italian government decided to shutdown all nuclear plants in the country in 1987. At that time, in the absence of a government policy on decommissioning, the Italian electric utility ENEL proceeded on the basis of the ‘safe storage’ strategy. Several reasons were behind the decision, including the unavailability of a national repository, the potential reduction in occupational dose and the financial advantage in delaying major costs. Therefore, the programmes aimed to finish all decommissioning activities and to delicense the sites around 2050.

Decommissioning activities for the safe storage strategy, however, did not begin at the rate that was initially planned, since several dependent conditions — such as regulatory, financial and technical requirements — were not fully clarified. In addition, the primary mission of ENEL was to generate and sell electricity, and the commencement of decommissioning activities was a low priority.

Along with the partial privatisation of ENEL, Sogin was created in 1999 as a separate company within the ENEL holding to carry out the decommissioning of nuclear plants. In 2000 Sogin became property of the Treasury and was completely separated from ENEL.

It was also decided that Sogin should take the responsibility for the decommissioning of other nuclear installations in Italy, namely those of the nuclear fuel cycle operated by ENEA, the state owned R&D organisation, and Fabbricazioni Nucleari (FN), an industrial fuel fabrication plant, formerly owned by Agip Nucleare. In August 2003 all licences of the fuel cycle facilities were transferred to Sogin.

Since the beginning of 2003, Sogin has also been responsible for the technical identification and engineering of a national repository for radioactive wastes.


On the basis of a strategy document presented to parliament at the end of 1999, the Italian government requested Sogin to complete the decommissioning of all nuclear plants before 2020. The main reasons for the decision were:

  • The retention of nuclear skills and knowledge is problematic in a country that has — at least for the time being — abandoned nuclear power.
  • Each nuclear plant was based on a single unit site and storage expenses could not be shared between any plants, increasing total costs.
  • More than 12 years had elapsed since all the nuclear plants had shutdown, weakening the argument for waiting for radioactivity to decrease.
  • The social and industrial context made it difficult to reassign plant personnel, so it was extremely important to maintain their services within the decommissioning sphere.
  • With good planning on a national level, a constant number of staff could be maintained, with personnel shared between sites; this could be achieved by accelerating the timescale.
  • The accumulation of decommissioning experience in a shorter period would allow the company to expand into the international decommissioning market.
  • The sites could be reused for other industrial applications, including electrical power stations.
In the developing the new strategic objectives the government recognised that they had to solve two additional issues: a technical problem and an economical one.

The technical problem concerns the construction of a national waste repository. The dismantling and the waste treatment activities can be fully implemented but, without a national repository, the conditioned wastes have to be kept on site in an interim store, preventing total release of the site and producing additional running costs. As a consequence, the national strategy plan calls for the siting of the repository by 2005 and for its operation by 2009. The decommissioning programmes of the four plants assume the availability of the national repository as a precondition to commence major dismantling activities.

The second problem resulted from the premature closure of all plants, namely that the accumulated decommissioning funds were insufficient. In the 1980s, ENEL, without any legal obligation, had created a decommissioning fund based on the US model and assumed a safe storage strategy. This fund was subdivided in two parts, one for power plant dismantling and waste management and one for fuel cycle closure.

Since the decisions to build and to shutdown the nuclear plants were taken by the country through government acts, the government decided that the additional costs of decommissioning had to be covered through electricity bills in the form of a dedicated surcharge. The responsibility of setting the surcharge — on the basis of the presented programmes and of the current state of the projects — was given to the National Authority for Electricity and Gas, an independent technical body.

Consequently Sogin developed in parallel the new licensing documentation, the new schedules and technical descriptions as well as the corresponding financial requirements. Those documents were submitted to the authority in September 2001, allowing them to define the amount of the surcharge on the electrical bills; the fee for the power plants is currently of the order of Euro ¢0.036 per kWh sold. Each year in September Sogin presents a status report and, if necessary, minor revisions to the documents; major changes are expected only at the end of a three year period.


The history of fuel cycle decommissioning strategy is somewhat different. In parallel to the closure of the power plants in 1987, the fuel cycle facilities (research, pilot laboratories and fuel fabrication facilities) were closed. The situation at that time was complicated by the fact that ENEA, the main owner and operator of these facilities, did not accumulate the funds required for decommissioning and the government did not identify a financing mechanism until 2000. The only activities carried out before 2000 were the treatment and conditioning of the most dangerous wastes and preparations for decommissioning.

In the 1999 strategy document mentioned earlier, the government decided that all fuel cycle facilities should also be decommissioned before 2020. The reasoning for this timescale is basically the same as for the power plant strategy, but with the following additions and differences:

  • The most urgent issue is the continuation of treatment and conditioning of a large variety of radioactive wastes, including liquids from fuel reprocessing, which will take several years.
  • No funds had been accumulated at the time of the decision for these facilities.
  • Completion of detailed radioactive characterisation and plant documentation for decommissioning planning would require additional efforts.
The most recent programme presented to the authority, was in September 2002. This programme requires an electricity bill tariff of about Euro ¢0.026 per kWh sold.


At the beginning of this year, as a result of increased concerns over terrorism, a decision was taken by the government to speed up at least those activities that had the greatest impact on the safety and security of all installations. On 14 February a ‘state of emergency’ for nuclear installations was declared until the end of this year and, through civil protection ordinance 3267/2003 signed by the prime minister on 7 March, a special commissioner — general Carlo Jean, the chairman of Sogin — was nominated to manage the emergency. In the same ordinance, Sogin was designated the operating arm of the commissioner. Special powers were given to the commissioner in decision making and licensing processes.

One of the first actions of the commissioner was to ask Sogin to review the decommissioning schedules of all plants and installations with the aim of reducing their total duration, taking advantage of the possibility of shortening the approval time for licensing processes.

The updating of the decommissioning schedules is underway, and it is currently expected that for the power plants the schedule reduction will not exceed two or three years, while for the fuel cycle facilities this reduction will be even shorter. This is due to several conditions, such as the need to not significantly increase the surcharge on the electricity bills, and to optimise resources and competencies at the national level.

Another very important factor taken into consideration is the link between the availability of a national repository and the decommissioning programmes. Since the time when the national repository will be operational is still uncertain, some storage facilities have to be used (or built if necessary) on all the nuclear plants and installations. Therefore an appropriate technical and economical balance should be reached between the need to accelerate decommissioning and the need to keep the electricity surcharge low.

A more accurate calculation of the amount of conditioned wastes to be stored has greatly influenced Sogin’s analysis. The initial estimate has dramatically decreased in the past few years due to better characterisation by the plants, better evaluation of the efficacy of decontamination techniques, and the harmonisation of the Italian release limits with those recommended by the European Union.

Taking all these considerations into account, the acceleration of the decommissioning of nuclear facilities is totally justified, not only on moral grounds, but also because of the consequences of a prolonged post-operational phase — namely, additional wastes and dose to the workers carrying out maintenance and inspection activities.

Another aspect influencing the current schedule revision is the increase in confidence in developing technical solutions and procedures for decommissioning all the plants. Although the activities are the same for all plants, their technical sequence is different, from site to site. Each plant has been identified as the lead plant for a particular activity. For example, since the demolition of the old stack at Garigliano could potentially have a greater environmental impact due to airborne releases, the site has been assigned the duty of demonstrating new codes. Again, for other reasons, the Caorso site has been assigned the responsibility of developing general design criteria for the waste management facility and to demonstrate the viability, in the Italian licensing context, of the Phadec decontamination technology.

The same approach is more difficult to pursue for the fuel cycle installations, because the variety of the situations is much greater. However, Sogin intends to carry out a similar effort in the standardisation of approaches and technologies. Rationalisation could be achieved by transporting and accumulating similar waste types — some of which are present in very small quantities in some installations — at particular sites, where the most appropriate treatment system could be built and operated. However this approach appears to face strong opposition from the local authorities.

The overall standardisation of nuclear facilities decommissioning has resulted from Sogin’s work in developing technical guidelines and through its support in defining national standards for all the major areas of decommissioning.

Related Articles
Enel statement 'Return to nuclear, an historic choice' in English

Italian nuclear fuel cycle facilities to be decommissioned


EUREX was a pilot reprocessing plant located at the ENEA R&D Centre of Saluggia

Main past activities:

• 1970-1975 : MTR (HEU) spent fuel reprocessing
• 1980-1983 : CANDU spent fuel reprocessing
• 1988-1991 : Pu nitrate-oxide conversion (via sol-gel)

Main decommissioning milestones:

• Within 2010: safe management of all radioactive waste produced during the past activities
• Within 2016 : decontamination and dismantling of the plant, safe management of the resulting material, free release of the site

Main decommissioning issues:

• Solidification of all liquid radioactive waste
• Dry storage of residual spent fuel in dual purpose casks


FN is an industrial fuel fabrication plant located in Bosco Marengo

Main past activities:

• 1973-1995: fabrication of fuel assemblies for Italian and foreign LWR
• 1996-2001: preparatory works for decommissioning

Main decommissioning milestones:

• Within 2004: decontamination and dismantling of equipment, safe management of the resulting material
• Within 2011: controlled temporary storage "in situ" of radioactive waste, transfer to the national repository, free release of the site

Main decommissioning issues:

• Residual nuclear material removal


The “Plutonium Plant” (IPU) was a pilot fuel fabrication plant located at the ENEA R&D Centre of Casaccia

Main past activities:

• 1968-1974: process development (sol-gel)
• 1977-1980: fuel fabrication for AECL Chalk River reactor
• 1990-1996: liquid radioactive waste management

Main decommissioning milestones:

• Within 2010 : management of all radioactive waste and nuclear material produced during the past activities
• Within 2016 : decontamination and dismantling of the plant, safe management of the resulting material, free release of the site

Main decommissioning issues:

• Removal of residual nuclear material
• Decontamination and dismantling of glove-boxes


OPEC was a post irradiation examination facility located at the ENEA R&D Centre of Casaccia

Main past activities:

• 1962-1990: post-irradiation examination of metal uranium and uranium oxide spent fuels (up to 2000 Ci - 74 TBq)
• 1992-1998: spent fuel scraps encapsulation, hot cells decontamination

Main decommissioning milestones:

• Within 2010 : safe management of all radioactive waste and nuclear material produced during the past activities
• Within 2016 : decontamination and dismantling of the plant, safe management of the resulting material, free release of the site

Main decommissioning issues:

• Removal of spent fuel scraps
• Management of residual radioactive waste


ITREC was a pilot reprocessing and re-fabrication plant (U-Th fuel cycle) located at the ENEA R&D Centre of Trisaia

Main past activities:

• 1975 -1978: reprocessing of Elk River spent fuel (U-Th)
• 1995 - 2000: solidification of liquid radioactive waste

Main decommissioning milestones:

• Within 2010: management of all radioactive waste produced during the past activities
• Within 2016: decontamination and dismantling of the plant, management of the resulting material, free release of the site

Main decommissioning issues:

• Solidification of U-Th highly radioactive solution (reprocessing “final product”)
• Dry storage of residual spent fuel in dual purpose casks


Table1: Italian nuclear plants to be decommissioned

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