In the name of God

Management of Spent Fuel from Bushehr Nuclear Power Plant

Atomic Energy Organization of (AEOI) Iran Radioactive Waste Association (IRWA)

Asghar Mohammadi Vienna, June 2016

1 Nuclear Power Plant in operation Type MWe gross, net construction start commercial operation Bushehr1 VVER-1000/V446 1000, 915 1975, 1994 Sept 2013 Total (1) 915 MWe net Nuclear power reactors planned and proposed Type MWe gross, net construction commercial operation start Bushehr2 VVER- 1057 2018? 2023 1000/V446B Bushehr3 VVER- 1057 2020? 2025 1000/V446B Makran coast ACP100 100 2018?

Makran coast ACP100 100

Darkhovin LWR,IR360 360 Bushehr 4 VVER ? Bushehr 5 VVER ? Other 1-4 VVER? 2 Bushehr nuclear power plant The Bushehr Nuclear Power Plant is a nuclear power plant in Iran 17 kilometres southeast of the city of Bushehr, between the fishing villages of Halileh and Bandargeh along the . The Bushehr Nuclear Power Plant (BNPP) is Iran's first commercial nuclear reactor. In 1994, and Moscow signed an agreement to construct the VVER 1000MWe light-water reactor, and construction started the same year. In September 2013, the Bushehr plant began producing power for the power grid. Location of Bushehr

3 Bushehr Nuclear Power plant

4 Core and Fuel Assembly Specification

5 6 What is spent fuel?

Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). o Radiation o Heat Generation o Criticality 7 Spent Fuel Management

8 Technical Features of Spent Fuel Storage o Wet Storage + excellent heat removal characteristics + good radiation shielding properties + optical transparency - Water leakage from pool - High operation cost - High corrosion - Low resistance to incidents such as earthquakes and attack . More than 30 years of operational experience have been accumulated all over the world for spent fuel storage in water.

9 o Dry Storage + Less expensive + provides all safety characteristics + doesn’t need electrical systems (necessary only in vault storage) + increasing the system reliability for longer periods + doesn’t need periodic maintenance and a constant fuel - Lack of spent fuel inspection o Types of Dry Storage • Vaults • Silos • Metal casks • Concrete casks

10 o Vaults A reinforced concrete building has cavities in the floor (vaults) which will have metallic cylinders that receive the SNF.

11 o silos The silos are horizontal or vertical concrete cylinders with metallic canisters inside them, the canisters contain SNF .Heat is removed from SNF by natural air convection through special ducts.

12 o Concrete casks Concrete casks have the same inner disposition as metallic casks. SNF are distributed in metallic baskets inserted inside steel cylinders, that are surrounded by concrete. The concrete cask provides neutrons and gamma radiation shielding. Heat is transferred through ducts, located at the cask wall, connecting the steel cylinders with external environment. Generally, concrete casks are heavier than the metallic ones because their walls are thicker, although they are less expensive .

13 o Metallic casks Metallic casks generally are made from cast steel with one or two lids that are bolted or welded at the cask body. The steel cask provides a leak-tight containment of the spent fuel and provides shielding against gamma radiation. Inside the cask, there is a special resin (e.g., polyethylene) that shields neutrons. There are cooling fins on the external surface of the cask for better heat transfer with the environment.

14 Advantages and Disadvantages on SNF Storage Facilities

15 Historical Evolution and Deployment of Spent Fuel Storage Systems

16 Bushehr Nuclear Power Plant Spent Fuel Inventory o Once a year refueling o Replacement one-third of fuel per refueling o Now there are about 150 fuel assembly in the reactor pool o Capacity of pool is about for 8 year reactor operation o So nuclear spent fuel must be managed.

17 Definition a project “spent fuel management from nuclear power plant “ documents needed to be generated in this activity are as follow: o Determining the amount of spent fuel generated in the country within next 40 years and studying the possible situations of nuclear power plants construction and transportation routs o Studying different methods for spent fuel storage and selection of the final method o Studying different kinds of spent fuel transportation and storage containers and proposing the best method o Identifying and setting stages and documents needed to be licensed for spent fuel transportation and storage based on international recommendations o Simulation of nuclear fuel and identifying radionuclides generated inside the fuel, during reactor operation time 18 o Simulation of spent fuel criticality o Simulation of spent fuel radiological shielding in normal operation and emergency accident o Thermal assessment of spent fuel in normal operation and emergency accident o Determining the safety class of transportation container and storage site o Requirements, regulations and criteria for designing dual purpose cask and road transportation requirements o Developing the acceptance and taking over the spent fuel o Primary safety assessment for storage and transportation cask of the spent fuel o Primary safety assessment for spent fuel storage site o Requirements, standards and criteria for needed design in designing spent fuel storage site 19  Studying Different Methods for Spent Fuel Storage and Selection of the Final Method

o Considering nuclear power plant proposed and planed o Regarding historical deployment of spent fuel storage , o The Contract Between Iran and (Repatriate) o Cost consideration o Advantage of dry Storage based on dual purpose cask such as : • No Spent Nuclear fuel corrosion • Passive cooling • Variable size of storage • Transport cask is the same as storage • Casks mobility • …. tacitly dry Storage based on dual purpose cask accepted. 20  Spent fuel storage potential locations o Inside of Bushehr Nuclear Power Plant + Doesn't need to transport + Doesn't need to new utility - Lack of space for storing the other spent fuel nuclear power plants - Decrease of safety due to increasing of volume spent fuel - Change in safety assessment Bushehr nuclear power plant - Raising concerns of stakeholders

21 o Talmesi site (Center of Iran)

- Need to transport +Safer and secure than the other option + enough space for increasing the volume of spent fuel + Less corrosion due to weather conditions + Centralizing all of spent fuel 22 ISFSI Facilities

23  Selection of dual purpose cask o Lack of experience in country about design of dual-purpose cakes o international experience o So now we selected TK-13 Dual Purpose cask o Then we recalculated design of parameter such as radiological shielding, criticality, thermal analysis and compared results with benchmark documents.

24 Overview of radiological shielding of TK-13 in the mcnpx2.6 code

25 The overall temperature distribution in the cross of dual purpose cask

26 Route of Bushehr nuclear power plant to Talmesi site

27 thank you for your attention

28 Any question?

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