Very low level waste management in Spain and in France

Transcription

1 Very low level waste management in Spain and in France From safety to waste acceptance criteria Industrial experiences Elena Vico, Mariano Navarro ENRESA - Spain Michel Dutzer ANDRA - France Disponet Peine - September 2010 ANDRA-ENRESA 2010

2 CONTENT 1- Motivations for the VLL disposal facilities in France and in Spain 2- Waste streams 3- Safety principles and design of facilities 4- Waste Acceptance Criteria 5- Acceptance process 6- Lessons learned 7- Conclusions 2

3 FOREWORD Presentation of ENRESA ENRESA is the Spanish state owned company responsible for long term management of spent fuel and radioactive waste and for decommissioning of nuclear installations. Budget (2010): 190 M (total) 35 M (LILW) 6 M (I+D) Staff (2010): 300 (170 technicians) STORAGE OF SF+ILW Collection of Transport NPP Pool Siting, Design and Construction Acceptance and Characterisation Of Waste Trillo NPP Jose Cabrera NPP R&D Treatment and Conditioning Storage and Final Disposal Remedial Actions in old Uranium Mills and Mines Support in Incidents Decommissioning of NPP 3

4 FOREWORD Presentation of ANDRA A French state owned company......in charge of implementing solutions...for long term radioactive waste management: - Research - Design, construction, operation, closure and monitoring of disposal facilities - Information Budget (turnover 2008): Research : additional tax on nuclear facilities (HL and LL-IL waste) ~97 M Industrial activities : contractual framework with waste generators ~62 M Public service (remediation of orphan polluted sites), inventory : subsidy ~ 4.5 M Staff( end 2009): 443 (engineers : 70 %) 4

5 1-Motivations for the VLLW disposal facilities in France and in Spain France: the identification in 2000 of a need for disposal of VLL waste A significant decommissioning programs under progress Nuclear research facilities : by dismantling worksites and 15 sites completely decommissioned Eurodif enrichment plant decommissioning Marcoule and La Hague UP2-400 reprocessing plants decommissioning Power plants: In the next 25 years total deconstruction of 9 power reactors A new regulation being prescribed for nuclear wastes A waste zoning to be implemented in nuclear facilities Nuclear wastes and conventional wastes No clearance level for nuclear wastes About 650,000 m 3 with a very low specific activity (range = a few Bq/g) or just potentially radioactive to be disposed of till 2030 A need for a safe and cost effective disposal solution 5

6 1-Motivations for the VLLW disposal facilities in France and in Spain France: waste zoning (1999 regulation) areas where there is no possibility of contamination or activation REFERENCE ZONAGE DECHET ZC ZONE CONVENTIONNELLE Cette zone produit des déchets conventionnels Pour tous travaux ou entreposages, Respecter les consignes relatives à cette zone. Date : Tél : A significant part of nuclear waste is just potentially radioactive Conventional waste REFERENCE ZONAGE DECHET ZN ZONE NUCLEAIRE areas in which waste is or may be contaminated or activated Nuclear waste Cette zone produit des déchets nucléaires Pour tous travaux ou entreposages, Respecter les consignes relatives à cette zone. Date : Tél : 6

7 1-Motivations for the VLLW disposal facilities in France and in Spain Spain: needs for developing of VLLW disposal The forecast of important volumes ( m 3 ) of wastes with a very low content of radioactivity mainly coming from the dismantling of NPP s (Vandellos 1, José Cabrera) The fact that the existing capacity ( m 3 ) of the high tech concrete vaults for LILW has a strategic value The implementation of this management option in France More than 70% of total RW has less than 100 Bq/g of specific activity The occurrence of some radiological industrial incidents in the past More safe and cost effective disposal solution 7

8 2- Waste Streams Spain: waste forecast inventory according to customers LILW 170,000 m 3 SF/HLW 13,000 m 3 3% OTHERS GLASSES 1% 22% OPERATION NPP s 1% NUCLEAR FUEL MANUFACTURING 72% NPP s DECOMMISSIONING OTHER ILW 20% 2% RR.II. SPENT NUCLEAR FUEL 79% (38,400 m³ as of 31/12/2007) 19,472 Fuel assemblies / 6,675 Ut (11,249 Fuel assemblies / 3,721 Ut as of 31/12/2007) LILW = Conditioned low and intermediate level waste (included very low level waste) SF/HLW = Spent fuel and high level waste in disposal canister (included medium level waste) NPP s = Nuclear Power Plants RR.II. = Radioactive Installations 8

9 2- Waste streams Spain: VLLW streams according to the nature of waste Waste conditionning prior to disposal Stabilisation facility Backfilling facility inert waste 30% incident 3% equipments, big components 7% metallic waste 53% compacted waste 2% grouted waste 5% Compaction facility 9

10 2- Waste streams Spain: VLLW National Inventory Decommissioning wastes Operating wastes Already generated

11 2- Waste Streams France: VLL waste forecast inventory according to customers Nuclear power plants Nuclear fuel cycle Radioactive spectrums the derivation of a forecast radioactive inventory Research Military applications 11

12 2- Waste streams France: VLLW streams according to the nature of waste Waste conditionning prior to disposal Stabilisation facility Solidification facility Compaction facility Compaction facility hazardous waste to be stablised 0,1% metallic waste to be grouted 12% sludge to be solidified 1% non metallic waste to be compacted 3% metallic waste to be compacted 6% metallic waste 26% Inert waste 52% Specification and waste acceptance criteria for each stream 12

13 3- Safety principles and design of facilities (1) General Fulfil the same basic safety objectives and criterias as accepted for the existing LILW facilities at Centre de l Aube and El Cabril The technical design was based on the regulations governing disposal facilities for nonradioactive hazardous waste in Europe Fundamental objectives in the design Ensure the inmediate and deferred protection of the public, the workers and the environment, during operation and after closure Ensure the control and surveillance of the site through exhaustive and traceable means regarding waste, the facility, workers and enviroment 13

14 3- Safety principles and design of facilities (2) Criteria applied to fulfil the objectives The use of isolation barriers to prevent radionuclide migration Limiting activity by waste package and by cell Setting up a surveillance period for a maximum of 30 years (France) or 60 years (Spain) Other technical options adopted in the design A leachate control system to collect the water that may come into contact with the waste The operation of the cell will be performed under a mobile roof in order to minimize the quantity of potentially contaminated leachates to be treated The accumulation of waste will be stable under disposal conditions and will be able to sustain the final cover 14

15 3- Safety principles and design of facilities (3) Requirement for the barrier Containment properties between wastes and the environment at least equivalent to those for non radioactive hazardous waste. Permeability < 10-9 m/s Thickness > 5 m In France a site that was selected with the required properties (clay layer) In Spain a containment barrier that was constructed with equivalent required properties (imported clay and bentonite) 15

16 3- Safety principles and design of facilities France : description of the facility (1) Cross section of a disposal cell Clay Sand Inspection hole Membrane Waste Clay Membrane Selected site near Morvilliers village, 2 km from Centre de l Aube Thickness of the clay layer : 15 to 25 m Permeability : 10 to 100 times less than the required value 16

17 3- Safety principles and design of facilities France : description of the facility (2) Construction Removal of the mobile shelter after operation of a cell Implementation of the clay capping Operation system 17

18 3- Safety principles and design of facilities Spain : description of the facility 18

19 3- Safety principles and design of facilities Spain : description of the operation 19

20 3- Safety principles and design of facilities Spain : Protection barriers Waterproof barrier: clay layer (1 m) and geobentonite layer (0.03 m) Drainage layers: two layers of gravel (0.3 and 0.5 m) Two waste sections separated by intermediate protection barrier Multilayer cover 20

21 4- Waste Acceptance Criteria An input: the safety assessment Performing the safety assessment Consistency with Centre de l Aube and El Cabril disposal facilities safety assessment: Considers the same water transfer scenarios and air transfer scenarios Takes into account: normal situations altered or accidental situations Assesses the operational period the post closure period An indicator : the impact radiological impact (msv) (in France) chemical impact As, Zn, Pb, Cd, Cr (VI), Cu, Ni, Sb, Hg, asbestos systemic or stochastic effects 21

22 4- Waste Acceptance Criteria The derivation of a radiological capacity For some scenarios the impact depends on the overall inventory of the facility Example : normal situation water transfer scenario Forecast inventory Impact Capacity In Spain, the total activity in the disposal vessels is limited to be no higher than 1% of the reference inventory of El Cabril LILW vaults. 22

23 4- Waste Acceptance Criteria The derivation of a acceptance limits for packages For some scenarios the impact depends on the specific activity of a package Example : normal situation handling operation Assuming a single radionuclide is disposed of in the facility Dose constraint (5 msv/year) Max specific activity (for instance 30 bq/g for the radionuclide) Acceptance Index class For the radionuclide (class 1 (10 1 Bq/g)) 23

24 4- Waste Acceptance Criteria General structure of waste acceptance specifications Waste accceptance process specification Describes interaction between waste generator and waste management agency General specification Generic criteria (accepted waste forms, general principles ) Refers to thematic specifications Thematic specifications Conditioning modes Radioactive content Waste to be conditioned in the disposal facility Waste tracking system 24

25 4- Waste Acceptance Criteria ACCEPTANCE CRITERIA FOR VLLW PACKAGES GENERAL CRITERIA VLLW packages will be accepted in terms of batches. Packages should be identified for its traceability, referred to a batch, and should indicate their activity values, etc. Inert waste and those equivalent to non-hazardous waste do not require previous stabilization process. The hazardous waste do. RESTRICTIONS Not radioactive content: explosive, corrosive, oxidizing, flammable, pyrophoric, with T>60, rottenable, fermentable Physical- chemical characteristics: Encapsulated sources, liquid aqueous or organic waste without pretreatment of solidification. 25

26 4- Waste Acceptance Criteria Spain RADIOLOGICAL CRITERIA PACKAGE Complementary treatment if needed: Stabilization, gap filling etc. DISPOSAL UNIT (UA) Is the set of the very low level radioactive waste (VLLW) and its eventual packaging BATCH OF VLLW-UA Package and, in some cases, a stabilization or filling material, which allows the identification, characterization, tracking and storage in compliance with the mass activity limits and other requirements and technical conditions fixed for its final disposal on cells 29 to 32. Set of VLLW-UA whose characteristics and origins allow an accurate description, aimed to be subject of an unique acceptance file (EA). 26

27 4- Waste Acceptance Criteria CRITERIA RELATED TO THE PHYSICAL & CHEMICAL CHARACTERISTICS INERT WASTE (RI) Origin and production process. Physical- chemical description of the waste and processes made. NON-HAZARDOUS WASTE (RN) Not metallic: quantifying cellulose components. Metallic: ratio of the different metals and ratio stainless steel / carbon steel, in case of Iron waste. HAZARDOUS WASTE (RP) 4 < ph < 13. Soluble ratio < 10% of the dry waste mass. Leaching limits. In case of not verification of leaching criteria, the waste should be stabilized. Identify complexing substances: inorganic, organic. Identify asbestos. 27

28 5- Acceptance Process Spain STEPS FOR THE ACCEPTANCE OF VLLW First stage: Generic Acceptance Second stage: Documental Acceptance Approval of the acceptance document Third stage: Contractual Acceptance Applies to a waste batch after being converted to VLLW-UA Radiological data verification for packages produced with generic acceptance Applies to packages and VLLW-UA batches conformed Transfer of the management responsibility to ENRESA Applies to individual waste packages with generic and documental acceptance 28

29 5- Acceptance Process Spain BATCH CONFIGURATION: PRODUCER PROPOSSES A SET OF PACKAGES FOR ITS STUDY AS VLLW PACKAGES ALREADY GENERATED (IDENTIFFIED). PACKAGES WITH MASS AND ACTIVITY DETERMINED. ENRESA DEFINES THE BATCH TO BE STUDIED THE PACKAGES CONFORMING A DEFINED BATCH WILL BE COMMUNICATED TO THE PRODUCER OR PRODUCERS BATCH REQUIEMENTS: THE BATCH IS NOT RESTRICTED ON THE NUMBER OR TYPE OF PACKAGES, ORIGIN OR PACKING THE BATCH CANNOT CONTAIN: HAZARDOUS WASTE WITH INERT OR NON-HAZARDOUS WASTE. PACKAGES REQUIRING ANY TREATMENT AT EL CABRIL REPOSITORY WITH OTHERS THAT DON T REQUIRE ANY TREATMENT. 29

30 5- Acceptance Process Spain A VLLW-UA BATCH IS ACCEPTED FOR ITS FINAL DISPOSAL THROUGH AN ACCEPTANCE FILE (EA): FIRST, IT DOCUMENTS THE COMPLIANCE OF THE VLLW PACKAGES AND THE BATCH CONFORMED WITH THE AC FOR VLLW PACKAGES SECOND, IT VERIFIES THE COMPLIANCE OF THE VLLW-UA BATCH AND THAT OF ITS BATCH WITH THE ACCEPTANCE CRITERIA FOR VLLW-UA RELATION BETWEEN VLLW PACKAGE AND VLLW-UA NO ADDITIONAL TREATMENT AT EL CABRIL REPOSITORY VLLW PACKAGES VLLW-UA 30

31 5- Acceptance Process Spain RELATION BETWEEN VLLW PACKAGE AND VLLW-UA HAZARDOUS WASTE STABILIZATION GAP FILLING COMPACTATION ADDITIONAL TREATMENT AT EL CABRIL REPOSITORY VLLW-UA VLLW PACKAGES VLLW-UA VLLW-UA 31

32 5- Acceptance Process France Similar process than in Spain However: No systematic control of documents prior shipment (2100 shipments in 2009) but quality insurance implementation required Inspections in the generators facilities Computer control by ANDRA of declaration by generator On line control of index of acceptance during deliveries Controls at delivery at the disposal site 32

33 6- Lessons Learned France Unconsistencies with conventional disposal facilities in the long term safety approach to assess the toxical impact Asbestos : long term re-use scenarios of the disposal facility should lead to a capacity. Conventional hazardous waste facilities have no such limitation a comparison study to be performed within the French national waste management plan Large disused components disposal The relevance of an acceptance index just based on specific activity specific safety scenarios Waste acceptance criteria based on the Acceptance Index does not take into account radiological capacity management Definition of batch, in particular for wastes, that are produced continuously and conditioned in the same workshops in a facility with different activities 33

34 6- Lessons Learned Spain Packages must be generated before ENRESA defines the Batch. But: It is possible to open the batch to include new packages, in that case all the documents related to the Acceptance File (EA) should be modified. Some packages can suffer additional treatments at El Cabril repository prior to its consideration as UA. Management of big equipment or components (batches?, test?, verification?, filling of voids?) Due to the heterogeneity of the UA is difficult to optimize the waste volume of the cell. Limitation of Fermentable materials (less than 10 %) There are producers who have a huge number of packages with 100 % of Fermentable materials (wood). The limitation has to be applied to the cell. 34

35 7- Conclusions A safe disposal solution well fitted to the radiological hazards with procedures that remain consistent with LIL wastes repositories Flexibility Types of waste form Disposal cells Handling techniques In France the opportunity of developping dedicated cells for large components is presently investigated In Spain two lines of the cell will be operating in parallel A cost effective disposal option However in France a significant increase of deliveries A risk of an anticipation of the saturation of the facility A need to improve densification of waste A challenge to recycle metallic wastes within the nuclear industry In Spain new containers for VLLW will be used to optimise the volume capacity of the cells 35