DECOMMISSIONING AND SITE RESTORATION IN BELGIUM

Transcription

1 DECOMMISSIONING AND SITE RESTORATION IN BELGIUM Jean-Paul Minon, general manager ONDRAF/NIRAS Origin and Development of Nuclear Applications in Belgium The very beginning of the Belgian nuclear industry started when a mining engineer of Union Minière du Haut Katanga found on 10 April 1915 while looking for extractable copper ore, important pitchblende deposits in the area of Shinkolobwe in the Katanga district of the former Belgian Congo. The production of Radium for medical applications began in July The production of Radium lasted till the seventies. During the war, Belgium helped its allies in their efforts to make available stockpiles of ores rich in fissile material. After world war two, as a counterpart, Belgium was given the opportunity to get a head start in the development of peaceful applications of the atom with the creation of the SCK CEN. At the SCK CEN the first pressurized water reactor outside the United Sates, was ordered in 1956 and put into operation in 1962; the reactor was closed down in In 1957, the international company Eurochemic was founded with the aim of demonstrating the reprocessing of irradiated fuel in economical conditions. The construction of the pilot reprocessing plant started in 1960 and operation began in Operations were going on up to 1974 when the plant was closed down. The SCK CEN and Eurochemic installations were located in the region of Mol-Dessel in the province of Antwerp. In the same region FBFC and Belgonucleaire were built, respectively for the fabrication of UOX fuel and MOX fuel. The production of MOX fuel at Belgonucleaire stopped in The production of radioisotopes for medical application was also investigated from the beginning on and started at an industrial level in 1971 with the creation of the IRE that was located in Fleurus- Farciennes. In parallel, the electricity companies constructed 7 nuclear power units at Doel and Tihange, for a current installed power of some MWe. The reactors were put into operation between 1975 and The phase out is foreseen by law between 2015 and 2025 after 40 years of operation. Dealing with liabilities All industrial activity inevitably ends up in a legacy consisting in obsolete installations and waste. That legacy can take various forms depending on the way operations were conducted and the end of activities has been forecast and prepared. The following cases can be distinguished. Historical situation : Umicore Olen The production of Radium, which started between World Wars I and II and terminated in the 70 s, happened mainly in a period where no specific nuclear regulation existed: the first law dealing specifically with nuclear activities was passed in 1958 and put into force by the Royal Decree of Although operation always happened according to the existing legislation and good industrial practices, termination of activities and waste management was not a matter of great concern as usual in the industry at that time.

2 - 2 - Because of the development of particle accelerators and nuclear reactors other substances could be produced with shorter half-lives, which gradually reduced the use of Radium for medical purposes. In Olen a stock of unsold Radium remained behind in the initial users packaging ; they were put in a central storage facility from the middle of the 50 s on with intermediate products and waste. The storage of primary materials, byproducts and waste and the release of treated liquid effluents gave rise to a dispersed pollution inside and outside the industrial premises. In the 70 s a start was made on dismantling the production installations. Between 1980 and 1982, 3000 t of radioactive material have been disposed of by see-dumping. However, the central storage and the local contamination inside and outside the plant remained. This represent a legacy of around m³ of Radium contaminated material ranging from a concentration of a few Bq/g to grams of Radium (former 1 Curie or 37MBq). Umicore in cooperation with the Flemish and federal authorities made repeated efforts to start a program to tackle this liability. The discharge river and its banks are currently decontaminated and plans are made to remediate the whole site. Today, a strategy has to be developed to define the long term management of that legacy in accordance with the other waste categories dealt with by NIRAS/ONDRAF. This will become possible when guidelines will have been issued by the federal authority to cope with such situations; indeed that situation is not conventional and the aim of remediation is to leave a better and safer situation to the future generation. Remediation is not possible without appropriate funding. It is obvious that funding of environmental liabilities was not a usual practice in the period of time we are dealing with. Funding has also to be based on stable regulation and established according to agreed long term management scenarios. Recently, under the impulse of NIRAS/ONDRAF, Umicore began to fund the liabilities of the Olen site. Further discussion, e.g. regarding the long term management scenarios, will determine whether the level of funding will be sufficient or not. Unprepared situation : SCK CEN In 1956, the SCK CEN was granted an operation license by the province of Antwerp for all the installations according to the existing legislation at that time. The license covered a 30 year period and had to be renewed in In that frame, in a short period of time the decision was made in 1987 to definitively shut down the BR3 reactor due to uncertainties about the embrittlement of the reactor vessel. For many years the SCK CEN played also a central role in managing the low level waste produced in the country waste produced in the nuclear power plants included. The installations of the waste department of SCK CEN were then operated for the treatment of solid and liquid waste arising in the country for many years. Although the waste treatment installations and the site had to be transferred to NIRAS/ONDRAF from 1981 on according to the Royal Decree creating the agency this transfer was not executed by SCK CEN estimating that its historical role in helping the industry managing the low level waste was not sufficiently recognized. In the same period a coincidence of different events lead to an accumulation of untreated waste in those installations. In 1982 an end was abruptly put by government to sea dumping of low-level waste without having prepared an alternative solution. The government also proceeded to important budget cuts which forced the research center to look for alternative sources of

3 - 3 - financing, e.g. the center contracted foreign waste producers, mainly in Germany, to treat their waste without necessarily having the capacity or even the installations to be able to execute the contracts. This was one of the causes of the so-called Transnuclear affair. After rather 30 year of operations with poor overhaul the waste treatment installations were also reaching their end of life. Facing that situation, government forced the transfer of the waste installations to NIRAS/ONDRAF in After evaluation of the estimated costs of the different liabilities, the funding of the dismantling and restoration works was organized trough different agreements with the electricity sector and Royal Decrees in NIRAS/ONDRAF was entrusted with the general management of the different projects in close cooperation with the nuclear operators: Belgoprocess for the waste installations and the SCK CEN for the BR3 reactor and some other installations on the SCK CEN site. Partially prepared situation : EUROCHEMIC The European Company for the Chemical Processing of Irradiated Fuels (EUROCHEMIC) was definitively shut down in January Reprocessing activities took place from 1966 to The decision to shut down was taken in 1971 in the knowledge that the provisions of article 32 of the statute of 1957 had to be complied with. That article specified that Upon the liquidation of the company an agreement shall be concluded with the Government of the Headquarter State as regards the possible taking over of all part of the installations as well as the storage and control of radioactive waste. There was never any question of leaving the reprocessing facility just as it was after shutdown. The participating countries in the international company Eurochemic assumed their responsibilities and funded a program to place the installation in safe conditions. The program encompassed the partial decontamination of the buildings and the stabilization of the wastes produced by the nuclear activities on the site. Specific strategies were adopted for each type of waste depending on the state of the art and the available technology at the time as in the case of the alpha-contaminated waste that was bituminized or the vitrification of the high activity liquid waste. Dismantling was not an issue due to the difficulties in Belgium to take a decision on resuming or not the activities of the plant. After 1975, a phase of forced co-operation between the member countries took place to cope with the obligations regarding waste management ending in 1984 when the site and the plant were taken over by Belgium. Operations were conducted by Belgoprocess created by SYNATOM that in 1986 passed the shares of Belgoprocess to NIRAS/ONDRAF when a moratorium on reprocessing was decided by government. Currently, the funding of the site restoration falls entirely under the responsibility of the Belgian government. However, a lump sum was granted by Eurochemic essentially to terminate the conditioning of the waste present on the site. Planned situations : the nuclear power plants and the MOX fabrication facility The existing power plants in Doel and Tihange are planned by law to be closed down between 2015 and The conditions and provisions for the dismantling of the power plants and the management of spent fuel are regulated by a law passed in The management strategies to be developed and the associated costs have to be estimated by Synatom appointed by law as the funding company for those liabilities. Those estimations are reviewed every three years by a

4 - 4 - dedicated committee composed in majority of independent experts; that committee relies on the binding advice of NIRAS/ONDRAF. More generally, each nuclear operator is since 1991 required to elaborate an intermediate decommissioning plan that has to be approved by NIRAS/ONDRAF. Three years before shut down the operator has to inform NIRAS/ONDRAF who has to approve his final decommissioning plan. In that frame the decommissioning plan of the MOX fabrication plant and its funding were approved by the agency by letter of 25 November However, it is worthwhile to notice that no specific law forces nuclear operators to fund their liabilities nor prescribes the grade of availability of the funds. A situation fully under control Main achievements There was obviously an important improvement the last decennia in coping with the different liabilities that were inherited of past activities or that are expected to arise as a consequence of the planned shutdown of nuclear facilities. Those improvements are essentially at management and organizational level. The funding of the restoration works was also progressively secured. A major achievement was certainly the law passed in 1997 that entrusts NIRAS/ONDRAF to establish an inventory of all nuclear sites and installations, to estimate the associated dismantling and site restoration costs and to check the sufficiency and the availability of the funding. That inventory is established every five year. It was established a first time in 2002 and passed to the responsible minister in January The second inventory was established end 2007 and passed to the responsible ministers in February The inventory dealt with 824 sites belonging to 628 nuclear operators owning 1546 licenses. The total cost for the dismantling and restoration of all existing nuclear sites, waste management costs included, amount 7,93 billion EUR and concern essentially 18 existing nuclear sites. Those costs are covered for 97% in 2007 in comparison with 85% in Main achievements were also reached regarding safety and technical waste management issues for the main liabilities. Most of the waste present on the Belgoprocess sites are now conditioned or are being conditioned in specially designed facilities. Worthwhile to mention is the termination in 1991 of the vitrification of the HLLW produced during reprocessing at Eurochemic. Where installations or processes didn t exist, new one were built and developed. For example, a special building was designed, constructed and put into operation in 2004 to treat and condition the ILSW inclusive Radium bearing waste produced at SCK CEN since the beginning of the research activities. The vitrification plant was redesigned to be able to treat and condition alpha bearing waste produced during the dismantling operation of Eurochemic and MOX fuel production; when dismantling of the MOX fabrication plant will occur, the produced waste will also be dealt with in that facility. The redesigned facility was put in operation in 2007.

5 - 5 - Dedicated storage buildings were built on the Belgoprocess site to guarantee the safe interim storage of the different waste categories. At SCK CEN the waste and fissile material stock has been significantly reduced and the necessary facilities made available if needed. The spent fuel of the BR2 reactor was sent for reprocessing partly to Dounreay in the United Kingdom and partly to La Hague in France. The spent fuel of the BR3 reactor that is too heterogeneous to be reprocessed is now safely stored in CASTOR-cask in an appropriate building on the Belgoprocess site. Solutions were also made available for the treatment of HLSW and ILSW in the redesigned vitrification plant. Significant goals were also met in dismantling installations. The dismantling of the Nuclear Steam Supply System (reactor vessel, primary loop, pressurizer, steam generator) of the BR3 reactor is now completed. The dismantling of the auxiliary systems is going on and should be ended in Last but not least, the decontamination of the main Eurochemic process building that started in 1990 is reaching completion and the conventional demolition of a first part starts today. This is a major achievement at international level; indeed, the feasibility of the full decontamination of a Plutonium contaminated installation is practically demonstrated this way The waste arising from dismantling is the main waste source NIRAS/ONDRAF will have to manage in the future. Waste minimization appears to be a strategic issue in planning and conducting dismantling operations. Decontamination techniques of surfaces as concrete scabbling and shaving and of materials as grit blasting and chemical wet decontamination were used intensively. As a result only a few percentages of the present materials on a nuclear site end as radioactive waste. Pending issues It has to be recognized that some issues are also pending awaiting a clear solution for the longterm management of the waste. Those issues are related to the long-term storage of conditioned waste. A first phenomenon is the degradation of waste packages during storage. A second is the apparition of unexpected behavior of the conditioned waste sometimes long after conditioning. First of all it is necessary to precise that those phenomena do not have any consequence for the operational safety inside the storage facility nor for the environment outside the facility. If needed the operator has to take the appropriate actions to maintain and if necessary to restore safety. The main question regards the long-term safety and the assurance that the waste remains compatible with its final destination. That question has to be tackled on a sound technical and scientific basis by analyzing and understanding first the observed phenomena and afterwards by

6 - 6 - defining witch remediation actions have to be applied. Those issues have also to be dealt with taking into account the long-term management system, e.g. the characteristics of the final disposal system. International cooperation appears to be essential to deal with such issues. At present, the main concerns consist of bituminized waste drums conditioned in the past by SCK CEN and Eurochemic. Other issues are related to small quantities of waste for which a specific solution has to be defined and engineered. The cost effectiveness is a concern in this case, where international cooperation can also be of interest. Global costs and financing Costs estimations were made in 1990 for both liabilities. Those estimations were based on the knowledge of the situation at that time. For the liabilities of Eurochemic and the waste department of the SCK CEN the first estimation in 1990 was 795 million EUR (2008). For the period the real expenses amount to 803 million EUR (2008). In 2006, the remaining program was estimated at 939 million EUR (2008). The nuclear liability of the SCK CEN was estimated in 1988 at 515 million EUR (2008). The real expenses for the period amount 172 million EUR (2008). The remaining program is estimated at 513 million EUR (2008). Although the knowledge of the real situation increases with time and recent costs estimations should be more reliable, costs estimation remains difficult due to the unavoidable evolution of the economic environment over the long time period involved and due to unexpected events that can influence negatively some issues. The liability of SCK CEN is funded by a segregated fund managed by NIRAS/ONDRAF and fed with money made available according a payment schedule organized by Royal Decree. The liability of Eurochemic and the former waste department of SCK CEN were funded by contributions of the Belgian State and the electricity companies for the period A lump sum was also granted by EUROCHMIC essentially for the treatment of remaining waste. Since 2003 the liability is funded by a levy on the kwh. It is worthwhile to notice that the funding was interrupted for two years in 2001 and 2002 without any interruption of the activities on site. Both liabilities are financed trough stable mechanisms Concluding remarks The nuclear liabilities are obviously a charge from the past if no funding is organized during effective activities to be able to cope with the obligations regarding dismantling, waste management and site restoration after termination of activities.

7 - 7 - On the other hand the liabilities are also opportunities for the future. Indeed, Belgoprocess and SCK CEN have built up a large industrial know how and experience in decommissioning nuclear facilities. Specific dismantling and decontamination techniques have been developed and are available for further use. The ability of proposing assistance in decommissioning projects to nuclear operators does obviously exist. Belgoprocess disposes of a large set of installations to treat almost all waste type. This is a main asset for the continuity of waste management in Belgium but also offers the possibility to propose treatment and conditioning services to foreign nuclear operators. The engineering capacity gained in developing solutions for many types of waste must also be highlighted. From a strategic point of view, it is essential that any delay at any stage should be avoided or at least minimized. This has to be associated with stable and long-term financing mechanisms with preferably one source of income. It has also to be recognized that costs forecasts remain a difficult exercise. Last but not least, effective waste management requires a comprehensive long-term management system to be able to issue clear waste acceptance criteria. In that way there is a need to know precisely what the source term is and what the final destination of the waste packages is. The law of 1997 regarding the inventory of nuclear liabilities is a clear answer to the first item. Regarding the final destination a decision was made by government in 2006 for the LILW-SL, but no decision was taken at that time for the long-term management of HILW-LL and spent fuel. It is the intention of NIRAS/ONDRAF to make the necessary elements available in the next coming years to enable the government to take a decision by That decision is necessary to place Belgium in the capacity to execute correctly the decisions regarding the nuclear fuel cycle whatever the decision itself. Jean-Paul Minon June 20, 2008