1 ARN Nuclear Regulatory Authority International Conference on Management of Spent Fuel from Nuclear Power Reactors 31 May - 4 June 2010, Vienna Austria Spent Fuel Management of NPPs in Argentina D.E. Alvarez and H.M. Lee Gonzales

2 Uses and applications of nuclear energy have begun in Argentina in 1950, the year that the National Atomic Energy Commission (CNEA) has been created Spent Fuel Management of NPPs in Argentina Wide variety of activities were performed in the nuclear field Applying the legal and regulatory provisions in force Management of spent fuel and radioactive waste

3 - National Congress Act Nº (1997) to regulate the Nuclear Activity - National Congress Act Nº (1998) todetermine the Radioactive Waste to determine the Radioactive Waste Management Regime (Nat. Radioact. Management Regime (Nat. Radioact. Waste Management Prog. - CNEA -) Waste Management Prog. - CNEA -) - Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (2001) Nuclear Regulatory Authority –ARN- (1997) to regulate and supervise to regulate and supervise the nuclear activity the nuclear activity Spent Fuel Management of NPPs in Argentina

4 Secretary of Energy Ministry of Federal Planning, Public Invest & Services Nuclear Regulatory Authority (ARN) Argentine Government Nucleoeléctrica Argentina S. A. (NA-SA) National Atomic Energy Commission (CNEA) NPPs

5 Spent Fuel Management of NPPs in Argentina Government of Argentina exercises state ownership of special radioactive fission material contained in spent fuels from any origin: NPPs and experimental, research and/or production reactors According to the Strategic Plan, the decision to reuse fissile material contained in spent fuel will be adopted before 2030 Meanwhile, the spent fuel generated by the NPP in Argentina is being stored in interim storages (Primary Responsible NA-SA) At decommissioning time, an appropriate transfer of Responsible Entity will be needed and before that a decommissioning license should be required by CNEA

6 Spent Fuel Management of NPPs in Argentina BUENOS AIRES EMBALSE NPP PHWR MW 700 km from Buenos Aires ATUCHA I NPP PHWR MW 112 km from Buenos Aires PHWR MW 112 km from Buenos Aires ATUCHA II NPP under construction

7 Spent Fuel Management of NPPs in Argentina CNA I is a PHWR (357 MWe) of German origin which is in operation since 1974 Former times: natural uranium fuel (0.71%) Between 1995 and 2000: fresh fuel gradually modified from natural to slightly enriched uranium (0.85 % nominal) Atucha I NPP

Fuel element composed by 36 bars (+ 1), active length of 5323 mm. Each bar contains 442 UO 2 pellets cladding in a zircaloy-4 alloy tube with an external diameter of mm and 0.5 mm thick. Fuel assembly (153.5 Kg of U) is very slender, total length of mm, external diameter of mm and a weight of approx. 200 kg. Total number of fuel elements in the reactor core is 252 Spent Fuel Management of NPPs in Argentina Atucha I NPP 8Burnup [MWd / tU] Refueling Natural uranium ~ ~ 1.29/day SEU (0.85%) ~ ~ 0.72/day

Spent Fuel Management of NPPs in Argentina Spent fuel is stored temporarily under water hanging vertically in stainless steel racks two Pool Buildings Atucha I NPP maneuvering pool + two decay pools maneuvering pool + four decay pools completed full 3240 FE initial capacity: 6944 FE positions compact arrangement: storing capacity of 8304 FE 9

Spent Fuel Management of NPPs in Argentina 10 With a load factor of 85%, the arrangement will satisfy the storage demand up to But the end of the design of life of the Plant would be reached in 2017: it will be required to arrange a minimum of 620 free positions inside of the spent fuel facility A decision about life extension or decommissioning should be taken in the near future + Atucha I NPP

Spent Fuel Management of NPPs in Argentina A simplified conceptual design of a dry storage is under development: underground vertical silos placed in a new building annexed to one of the Pool Buildings Implementation of a dry storage seems to be the best solution to cover necessities to create additional capacity for: Storing the spent fuel (extension of life) orStoring the spent fuel (extension of life) or To transfer all the spent fuel out of the NPP in the case of decommissionTo transfer all the spent fuel out of the NPP in the case of decommission Atucha I NPP 11

Spent Fuel Management of NPPs in Argentina Atucha II NPP CNA II is a PHWR similar to CNA I. Start operation in Spent fuel will be storaged under water untill a dry storage alternative will be defined Pool Building 12

13 Spent Fuel Management of NPPs in Argentina Embalse NPP CNE reactor is a typical CANDU 6 (648 MWe) on load PHWR that is in operation in Argentina since 1984

Embalse NPP Spent Fuel Management of NPPs in Argentina Fuel bundles are composed by 37 bars of mm length. Each bar, containing 38 UO 2 pellets (natural uranium), is cladding in a zircaloy-4 alloy tube. Fuel assembly has an external diameter of mm and 22 Kg of UO 2 14

15 Spent Fuel Management of NPPs in Argentina Embalse NPP Refueling frequency at full power is 15.2 fuel bundles per day, maximum burn up 7800 MWd/tU “Calandria” has 380 horizontal pressure tubes /channels with a capacity of 4560 fuel bundles (12 per channel)

16 Spent Fuel Management of NPPs in Argentina Embalse NPP Leaving the core, the spent fuel bundles are transfered underwater to the reception bay (capacity: 4800 bundles). They are disposed horizontally on trays of a double array of 12 bundles each one which are transfered to the storage bay and stocked in piles (capacity for spent fuel bundles, it means 10 years at maximum power)

Spent Fuel Management of NPPs in Argentina Embalse NPP 17 A dry storage alternative was implemented in 1993 to cope with the spent fuel storage demand up to the end of the operative life of CNE. Spent fuel bundles remain at least 6 years in the wet storage for thermal cooling and radioactive decay after being transfer to the dry storage: concrete “canisters” arranged in a yard at the power station site.

Spent Fuel Management of NPPs in Argentina Embalse NPP 18 Each full loaded canister contains 9 steel sealed piled baskets, each one with 60 bundles Canisters are 6.3 m high vertical cylinders and approx. 3 m external diameter. Cooled by natural convection, were designed to support some accidental events as earthquakes, floods, tornadoes and the risk of explosions No especial activities of maintenance are necessary when the canisters are filled and sealed. At present, there are 152 full loaded silos from 216

Spent Fuel Management of NPPs in Argentina Embalse NPP Canisters yard is inside a double fence which surrounded the NPP for security protection CNE was designed with a 30 years nominal life (load factor of 80%). Due load factor = 88% in the last 10 years, the plant design life will be reached in Life extension project is under development The modular design of the dry storage allows to be enlarged, with no fulfillment of special requirements 19

Spent Fuel Management of NPPs in Argentina 20 Conclusions A decision about the fuel cycle back-end strategy will be taken before It is important to mention that, recently, the National Supreme Court has been issued on a cause related with a possible entry to the Country of the spent fuel from an Australian reactor constructed by an Argentine enterprise, based on the fact that spent fuel is not radioactive waste Meanwhile, the spent fuel in each Nuclear Plant is temporarily storage on site. In Atucha I, the spent fuel is being storage in pools but a dry storage design is under development. Embalse counts with a dry storage since 1993; the spent fuel, after certain period of time kept in wet storage, is transferred to dry storage silos. Enlargement of the spent fuel interim storage capacity at CNE is made easily through the construction of new modules of dry storage silos

The management of the spent fuel, during the operation life of the Nuclear Power Plants, is a responsibility of the operator (NA-SA) and at the time of decommissioning the responsibility will be of the Responsible Organization (CNEA). A reasonable time before that moment both Entities must come to make the appropriate transfer agreements as well as CNEA should start the decommissioning license procedure Spent Fuel Management of NPPs in Argentina Conclusions (cont.) 21

22 THANK YOU FOR YOUR ATTENTION Spent Fuel Management of NPPs in Argentina