IAEA Technical Meeting on Spent Characterization 12-14 November, Vienna

Spent VVER Fuel Management & Characterization in .

Mykhailo Yatsenko Management Engineer Energoatom Kiev, Ukraine Competence and responsibilities of the State Enterprise National Nuclear Energy Generating Company Energoatom

According to the Law of Ukraine "On the use of nuclear energy and radiation safety" Energoatom is the operator responsible for the safe operation of plants in Ukraine:

• Zaporizhzhya NPP – 6 units VVER-1000, SFSF (Spent fuel dry storage); • Rivne NPP - 2 units VVER-440, 2 units VVER-1000; • Khmelnitsky NPP - 2 units VVER-1000; • South-Ukraine NPP - 3 units VVER-1000;

Nuclear facilities planned to be created by Energoatom: • Power Unit 3 of Khmelnitsky NPP; • Power Unit 4 of Khmelnitsky NPP; • Centralized Spent Nuclear Fuel Storage Facility. State policy and strategy for spent fuel management

• Energy Strategy of Ukraine (up to 2035); • Strategy for Radioactive Waste Management in Ukraine (up to 2060); • National Special Ecological Program on Radioactive Waste Management; • Program on Chornobyl NPP Decommissioning and Transformation of Shelter Object into Ecologically Safe System.

At present, there is no decision on the best option for SNF handling in the world nuclear power industry. Each country that operates nuclear power plants independently defines national approaches to SNF handling, which depend on specific technical, economical and political conditions.

• Ukraine as many countries have selected the option of deferred decision. • The main activity of the final stage of the fuel cycle is focused on SNF storage technologies. Spent VVER fuel management in Ukraine

Current option: Planned option Current option:

ZNPP Dry SFSF : CSFSF project : SFA transferred to Russia for storage and • 50 years of • 100 years of storage reprocessing . storage period; period; Products from reprocessing will be • 380 casks (VSC- •480 casks (HI- returned to Ukraine 24 VVER); STORM 190); after 2022. • 9 120 SFA. • 16 529 SFA. State policy and strategy for spent fuel management

• Returning of reprocessed products to Ukraine since 2022; • SNF storage (for 50 years) in the spent fuel dry storage at the Site of ZNPP; • Сonstruction of the dry spent fuel storage (for 100 years) in Exclusion Zone (сommissioning is scheduled since 2020); • Сonstruction of the storage for Equipment testing on Rivne NPP reprocessed SNF products in Exclusion Zone is scheduled for 2022; • Long-term storage of high-level radioactive waste after reprocessed SNF since 2022; • Life extension of the spent fuel dry storage at the ZNPP’s site for the period of more than 50 years.

Storage of vitrified HLW waste from VVER SNF reprocessing Key unsolved problems in SNF management

Key unsolved problems: • Storage at NPPs and sending of untight SFA for reprocessing; • Life extension of interim SNF storage facilities; • Long-term storage of SNF reprocessed products; • Disposal.

Causes of unresolved problems: • Complexity of safety justification of life extension of SNF interim storage facilities; • Lack of technical solutions on SNF disposal; • Technological complexity of this process; • High costs. SFSF at Zaporizhzhya NPP

• On-site storage capacity provide place for storage of SNF generated by the 6 units at ZNPP • Casks: VSC-24; • Burnup credit is used; • Design lifetime: 50 years of storage Storage area period; • Design capacity: 380 casks; 9 120 SFA; • Storage of leak-tight fuel only; • Key parameters of fuel: burnup, initial enrichment, leak-tightness.

100th anniversary canister Characterization of SNF before storage at ZNPP For SFAs that will be loaded into cask to store, the following data should be determined: • Passport number; • Distribution of burnup by SFA height; • Average SFA burnup; • Cooling time; • Residual heat; • Initial enrichment; • Nuclide inventory;

As an example All parameters a determined by calculation and operating history (when FA was loaded/unloaded to the core).

At Zaporizhzhya NPP we also have a device for burnup measurements (fork detector). Data management on ZHNPP

For all SFA in cask specific passport is designed. It’s include: • Main characteristics of FA; • Results of fuel leak-tightness control; • Nuclear safety calculation for FA; • Radiation doses on personel during loading; • Other information.

The passport for loading agreed by the state regulatory body and is necessary for permission to load a cask.

The passport for each download is stored throughout the life of the storage Form for main characteristics of facility. FA CSFSF project scope

• CSFSF capacity will provide place for storage of SNF generated by the 3 Ukraine’s NPPs; • CSFSF design capacity: 12 010 SFA of VVER – 1000; 4 519 SFA of VVER – 440; • Period of filling up the designed CSFSF capacity with spent fuel will be 50 years; • Design lifetime – 100 years; • CSFSF will be located in Chernobyl exclusion zone; • Start-up process includes: start-up complex (94 casks) , I expansion complex II expansion complex, III expansion complex; • Possibility of storing unthight SFA; • Special storage equipment will be delivered by Holtec International. • Start of operation – 2020. Holtec International Technology MPC HI-STAR 190 • A seal-welded double walled enclosure of all stainless • For storage and transportation steel construction with two of MPCs; lids; • Vertical storage; • Fuel basket is made from high Horizontal transportation; temperature aluminum • Consist of three shells; boron carbide metal • Helium-filled localization barrier; matrix composite material. • In CSFSF planned to use for • Two modifications: transportation. - MPC -31 (VVER-1000); - MPC-85 (VVER-440). HI-TRAC 190 HI-STORM 190 • Vertical, ventilated, • MPC transfer cask: cylindrical overpack; - From spent fuel pool; • Carbon steel encasing - To HI-STAR cask. concrete; • Consist of three shells; • SNF protected from • Designed and fabricated to extreme impacts of allow vertical handling while natural and man-induced meeting heavy-lifting origin during storage in requirements; HI-STORM. Data management on CSFSF (planned)

• The main characteristics to be determined during loading MPC- 31/85 cask before transfer to storage site:

Parameter Reason Residual heat: Burnup, To execute temperature Cooling time requirements of zone loading Radiation Both gamma and neutrons; for safety during management & storage Initial enrichment For safeguards, further calculation Assembly identity For account for all materials, identify problem tapes for future reference Nuclide inventory To account for the amount of fissile material, for further calculations Decay heat: aspects & uncertainties The importance and necessity of thermal calculations is justified by the following factors: • Zonal loading of SFA, large thermal capacity of the cask (33 and 38 kW); • Most degradation mechanisms are temperature dependent with rates generally increasing with temperature; • Temperature and thermal capacity are some of the main characteristics when considering repository design.

Heat calculation for HI-STAR Zone loading diagram Deep geological repository With the EU support, INSC U4.01/09 –B project is underway, and main tasks are: • defining a process that will allow the selection of a technically suitable and socially acceptable site for the placement of radioactive waste; • developing a detailed plan and cost estimation for the geological disposal in Ukraine; • training of experts in safety assessment, safety justification, program management, etc., in relation to development of deep geological repository; The stage that is taking place now: developing a general plan (roadmap) for creating deep geological repository project in Ukraine. At the legislative level, we have not made a final decision on the question of SNF disposal. Conclusions, challenges • Ukraine has developed a multi-component system for SNF management; • Sufficient attention is paid to characterization issues in preparing SNF for long-term interim storage; • Work is underway to correct uncertainties in determining the characteristics of SNF, new and alternative measurement techniques are being introduced; • In Ukraine, at the moment there is no clear list of characteristics necessary for determination in the preparation of spent nuclear fuel for deep geological disposal; • Now we are very interested in the experience of our international colleagues in aging management, life extension programs for dry storages; • The issue of geological disposal of SNF at the initial stage. Thank you for attention!