Management of radioactive waste
One of the Environmental Directives of Iberdrola Generación Nuclear is related to radioactive wastes and spent fuel. The Company is committed to assuming its responsibility as regards radioactive waste and spent nuclear fuel, from their generation through to their final transfer to an authorised management agency, in accordance with current legislation.
Currently all of Iberdrola's nuclear power plants in operation are in Spain, but if Iberdrola Generación Nuclear expands its nuclear power interests to other countries, the relevant national and international legislation, regulations and requirements will be taken into account.
In the case of Spain, currently the only case applicable for Iberdrola Generación Nuclear nuclear business relating radioactive waste management, the legal and national management framework is the following:
The concept of radioactive waste is defined in Article 2 of Nuclear Energy Law 25/1964:
“Radioactive waste is any material or product for which no further use is intended, and which contains or is contaminated with radionuclides of concentrations or activity levels higher than those established by the Ministry of Energy, following a report by the Nuclear Safety Council”.
The classification of radioactive waste in Spain is based on the planned final management, as referred to in successive national reports on the Convention for the Safety of Spent Fuel and Radioactive Waste Management (Joint Convention), which was signed in Vienna on September 5, 1997, being ratified by Spain and published in the Official State Gazette on April 23, 2001.
The classification considers the initial activity of the waste and the half-life of the radionuclides they contain, which can be short or intermediate-lived (less than 30 years), or long-lived when their half-life is longer. to this value. In practice, the different categories of facilities are comparable to the radioactive waste classification criteria adopted by the International Atomic Energy Agency (GSG-1) and the European Commission.
- Low and Intermediate Level Waste (LILW) comprises waste with an activity level essentially caused by the presence of beta- or gamma-emitting radionuclides with a short or intermediate half-life (less than 30 years) and with a very low, limited content of long-lived radionuclides. This includes Very Low Level Waste (VLLW), comprising a subset of low and intermediate level waste, and in general revealing specific activity levels of between one and 100 Bq per gramme, potentially rising as high as several thousand in the case of certain radionuclides with low radio-toxicity, or in the case of small amounts. Both types are disposed of at El Cabril Disposal Facility.
- High Level Waste (HLW) contains long-lived alpha-emitters with a half-life of more than 30 years, in appreciable concentrations which generate heat because of the effect of radioactive disintegration, as they have a high specific activity. The main exponent in this group is spent fuel (SF) discharged from nuclear reactors. This is currently stored in the pools and the Individualised Temporary Storage (ITS) facilities of the nuclear power plants.
- Special Waste (SW) category refers to additions for nuclear fuel, neutron sources, used in-core instrumentation, or replaced components derived from the reactor vessel system and the internal reactor components, generally of metallic nature. As long-lived waste with a significant activity level, temporary storage and disposal of such materials is handled similarly to HLW.
According to the provisions of Article 38 bis of Nuclear Energy Law 25/1964, of 29 April 1964, the management of radioactive waste, including spent nuclear fuel, and the decommissioning and dismantling of nuclear facilities constitute an essential public service reserved for State ownership, entrusted to the public corporation Empresa Nacional de Residuos Radiactivos, S. A., S.M.E. (Enresa) in accordance with the terms of the General Radioactive Waste Plan (GRWP) approved by the Government.
The GRWP Plan is the official document drawn up by Enresa that compiles, the strategies, the required actions, and technical solutions to be undertaken in Spain in the short, medium and long term for the purpose of the responsible and safe management of spent nuclear fuel and radioactive waste, the decommissioning and dismantling and of nuclear facilities and all other activities connected with the foregoing, including economic and financial provisions and the measures and instruments required for implementation.
The Plan is approved by the Government, at the proposal of the Ministry for Ecological Transition and Demographic Challenge (MITERD), following a report from the Nuclear Safety Council (CSN), and consideration of the opinions of the Spanish Autonomous Regions with regard to the regulation of territory and environment, industry and social agents, as well as a public consultation process conducted via the MITERD website. The Spanish Parliament is subsequently informed of the approved Plan. It is periodically reviewed and updated.
Since ENRESA was created, there have been six revisions of the GRWP, which have set the lines of action and objectives of the comprehensive waste management system that Iberdrola Generación Nuclear, as the company that owns and operates nuclear power plants, has incorporating, developing and implanting. The 7th GRWP is currently in the final phase of reviewing and approval.
The objective of all phases of the management of radioactive waste and spent fuel is to have effective measures to protect workers, the public and the environment from the potential risks and harmful effects of ionizing radiation, now and in the future, as stated in the Joint Convention.
Operational Radioactive Wastes
In accordance with the Nuclear and Radioactive Facilities Regulations (RD 1836/1999), to obtain and renew the operating authorization, the nuclear power plants of Iberdrola Generación Nuclear must submit a Radioactive Waste and Spent Fuel Management Plan (PGRyCG) in coherence with the GRWP national strategy. The purpose of the PGRyCG is to collect the criteria and methods that ensure that the management of radioactive waste generated at the facility is safe, traceable and optimized considering the advances in regulations and technology, and taking into account:
- The current situation at the facility, in terms of waste generation and management.
- The identification of the origin of the waste.
- The study of the alternatives for the management systems and processes and their improvements.
- The justification of the suitability of the management that is carried out or the advisability of implementing improvements.
- The planning for implementation of the identified improvements.
The plan is part of the objective of improving the management of waste generated at each facility. In particular, the owner of each nuclear power plant must keep its waste inventory updated, minimize its generation, recycle and value generated waste to the extent that this is technically and economically possible, and condition the final residual materials for disposal. The Plan also serves to guarantee that there is no radioactive waste that is evacuated by conventional means.
The PGRyCG considers the set of risks, both radiological and of another type, associated with radioactive waste, to define global solutions.
The Consejo de Seguridad Nuclear (Council of Nuclear Security), responsible body in Spain for Nuclear Safety and Radiation Protection, approves the PGRyCG of the Nuclear Power Plants and conducts periodic inspections to verify compliance. Additionally, the International Atomic Energy Agency (IAEA), as the international body responsible for fulfilling the No Proliferation Treaty, controls the inventory of spent fuel stored at power plants.
The contract between ENRESA and the NPP’s licensees for the management of radioactive waste generated in the operation and dismantling of the nuclear power plants was approved by the Ministry of Industry in 1989 and is valid until the end of the dismantling of each plant. The purpose of this contract is to establish the terms and conditions under which ENRESA provides waste management and dismantling services to the nuclear power plants. During the operation, ENRESA defines the waste acceptance criteria for transportation and disposal of the conditioned wastes at El Cabril Disposal Facility and promotes the necessary optimization actions. The producers condition the waste generated according to these instructions and contribute to the optimization and improvement of the system.
As indicated in the Environmental Directive of Iberdrola Generación Nuclear, the company applies the general principles of prevention, reusing, segregation and recycling and recovery in the management of radioactive wastes to the extent that it is technically and economically feasible.
Prevention is based on the contained use of raw materials and the restriction of materials and products entering the radiological controlled area to avoid possible radioactive contamination. Further application of this principle includes significant reductions in generation achieved through:
- Good control of technical processes where waste is generated (i.e. minimizing leaks, monitoring filters efficiency, etc.).
- Modifying and improving those processes (i.e. upgrading demineralizers efficiency, increasing compacting capacity, etc.).
- Introducing innovative new processes (i.e. in-drum drying system, reanalyzing scale factors for clearance levels, etc.).
Iberdrola Generación Nuclear applies the principle of reutilization by encouraging additional use of materials which have been found clean and without risk to personnel and pollution control (reuse of personnel working clothing prior to washing, personal tools).
The principles of separation and recycling try to manage the wastes following the criteria for source minimization (for which infrastructure has been implemented to separate the waste at collection points where products are collected separately and, where necessary, adopting human resources that perform specific tasks of direct measurement of radioactive waste, to select and separate those without contamination). The promotion of reutilization, as well as separation, and recycling is done in the training sessions taught by staff in aspects of environmental and radiation protection.
In regard to recovery, Iberdrola Generación Nuclear processes with authorized managers all collected sub products (paper, cardboard, scrap metal, plastic) with the aim of giving value to these materials as a solution before considering them waste to be disposed of.
Iberdrola Generación Nuclear also works with the competent bodies to obtain authorizations for clearance of radioactive waste from regulatory control, such as waste oil, sludge or metallic materials with very low activity. This management contributes to minimize the volume of waste to be disposed of at El Cabril disposal facility.
Extensive Research and Development and Innovation is either promoted or supported by Iberdrola Generación Nuclear in this area in coordination with ENRESA, R&D bodies and national authorities.
The Iberdrola Generación Nuclear’s performance indicators related to the different types of radioactive waste are monitored and controlled by the corresponding committees of the integrated management systems of the plants. All activities and processes related to the management of radioactive waste at Iberdrola Generación Nuclear are monitored and audited by the quality assurance units, which are independent of the operational hierarchical line and are only accountable to the general directorates of the nuclear power plants. This guarantees the appropriate approach to monitoring, documentation, minimization and control activities of tasks and processes related to radioactive waste and its optimized generation.
Safety assessments of different kinds and frequencies are carried out during the whole life of the projects. Specifically during the operation phase the following amongst others can be mentioned: annual quality assurance audits, biennial company safety review board audits, decennial comprehensive periodic safety review. All of these are performed by the licensee, in addition to the frequent audits performed by the regulatory authority.
Decommissioning Radioactive Waste
As mentioned before, according to the Spanish legislation the responsibility for the management of activities arising from the decommissioning and dismantling of nuclear facilities in Spain lies with ENRESA.
The financing of all the activities of the GRWP will be carried out through the “Fund for the financing of GRWP activities” constituted for this purpose, regulated by the sixth additional provision of Law 54/1997, of 27 November, declared in force by Law 24/2013, of December 26.
According to RD 102/2014, ENRESA is responsible for carrying out the necessary technical and economic-financial studies that take into account the deferred costs derived from its tasks to establish the corresponding economic needs and for managing the Fund for financing the activities of the GRWP. The control of Enresa's actions and plans is legislated in Article 10 of the same RD.
Iberdrola Generación Nuclear contributes to the GRWP fund through the payment of a fee for each kilowatt hour generated from nuclear energy throughout the operating lifetime of their facilities. This fee is regulated in the Sixth Additional Provision of Law 54/1997.
The article 6.c) of RD 102/2014 states that the GRWP must contain an inventory of all spent nuclear fuel and radioactive waste, as well as estimates of future amounts, including those from decommissioning. This inventory shall clearly indicate the siting and amount of spent nuclear fuel and radioactive waste, in accordance with a classification that considers the final management planned for it. The inventory estimated by Enresa is public, can be found on its website and is also included in the GRWP.
The last Enresa’s estimates (from reviewed version of 7ºPGRR, in approval process) indicate that the dismantling of all the NPPs in Spain will produce 91,900 m3 of VLLW, 38,500 m3 of LILW and 878 m3 of SW. The amounts corresponding to Iberdrola Generación Nuclear facilities rises to some 29,000 m3 of VLLW, 18,600 m3 of LILW and 250 m3 of SW. The management of all these decommissioning wastes are Enresa’s responsibility.