LEADER Work Package 2

1. LEADER Work Package 2 Status of activities Giacomo Grasso on behalf of Carlo Artioli – Work Package 2 leader UTFISSM-PRONOC ENEA LEADER PCC meeting Bologna, October 27th, 2011

2. Outline • WP2 objectives and activities • Tasks 2.1 to 2.5 status and planned actions • Documents and timing • Conclusions

3. WP2 objectives ALFRED domain LFR domain • Critical review of the ELSY (6th FP) core • General specification for the updated LFR industrial plant • Investigation of the possibilities for the adiabaticoperation of the core • Estimation of net MA burningcapability (dynamicbehaviour) • Definition of the criteria for demonstrating the LFR industrial plant • Conceptualization of the ALFRED core and design of fuel pin and elementarycell • Characterization and assessment of the ALFRED core

4. WP2 activitives ALFRED domain LFR domain • Definition of the adiabatic LFR reference configuration • Characterization of the adiabaticcore • Evaluationof evolutionfrom start-up core to the adiabatic one • Outline of strategies for waste management • Definition of the parameterswhichguarantee the consistencybetween ETDR and LFR • Definition of the reference ALFRED core configuration • Characterization of the ALFRED core • Preliminaryuncertaintiesanalysis

5. Task 2.1 – status As known, a core configuration for the industrial size LFR already exists (formerly back-up solution in the ELSY project).

6. Task 2.1 – status Done: review of existing LFR configuration for pointing out the issues to be solved 1) Single batch approach w/ open fuel cycle  high initial reactivity (1340 pcm)  insufficient peak burn-up (75 MWd/kg < 100 MWd/kg design goal) 2) Reactivity control system  currently insufficient for 1-batch MOX core  impact on hot spots 3) Reactivity coefficients  inadequate method for local void coefficient  no local void coefficient outside the core (above, below)  positive temp. coefficient at EOL 4) DPA calculations  core barrel value exceeds design limit (3.7 dpa > 2 dpa)  no data above/below core (diagrid/shielding)

7. Task 2.1 – status Done: proposal for a new core configuration complying with the solution of all the issues pointed out in the critical review of ELSY (together with some inconsistencies in the previous design), and implementing the adiabatic core concept.

8. Task 2.1 – to do • Assessment of the proposed core configuration to comply with all design goals and respecting all design limits (ONGOING) • Evaluation of detailed power distributions in the core needed for T/H analyses and of all reactivity coefficients needed for safety verifications A new scheduling of activities has been proposed and agreed by all partners. Release of D05 is expected by the end of the year.

9. Task 2.2 – status The design of the ALFRED fuel pin, elementary cell and Fuel Assembly has been performed according to a “comprehensive” approach, considering T/H and preliminary safety (ULOF) issues. A core complying with 300 MWth and a sufficient shielding of the Inner Vessel has been then arranged. 171 16 108

10. Task 2.2 – status Preliminary evaluations have been performed on the proposed core configuration, confirming its viability from a T/H and safety point of view. Clad failure time under EOL and ULOF conditions: ~ 31 hrs, well above the design goal of 30 min.

11. Task 2.2 – to do • Assessment of the proposed core configuration to comply with all design goals and respecting all design limits (ONGOING) • Evaluation of detailed power distributions in the core needed for T/H analyses and of all reactivity coefficients needed for safety verifications The complete neutronic characterization of the ALFRED core is ongoing. Release of D07 is expected by the end of the year.

12. Task 2.3 – status Done: - CFD analysis of flow through ALFRED rod bundle with EFIT spacer design (first step towards selection of reference spacer design). - preparation of ALFRED core model for evaluation of core T/H, including temperature profiles and hot spots identification, and for setting a orifice gagging scheme. Data along the axis FLOW Data line Plane 1

13. Task 2.3 – to do CFD evaluations of pressure drops through FA spike and funnel have been decided and will be performed in a short time. CFD analysis of flow through ALFRED rod bundle with SRS spacer design will be performed. On request there is also the possibility to analyze another alternative spacer design. Oct Nov Dec Jan 2012

14. Task 2.4 – status The ALFRED and LFR concepts have been defined, and the general design is almost complete. Top Grid Preloaded Spring Ballast Lead Free Level (during refueling) FAs Diagrid

15. Task 2.4 – to do Several analyses are still ongoing to asses the final core design. Actions for speeding up times for respecting the schedule.

16. Task 2.5 – status Preliminary activities have been done to evaluate the transmutation of Ta, a candidate coating material for cladding and SG tubes. Results showed important transmutation rates within the core, suggesting the rejection of this material – at least in active region. Further analyses are in stand-by, waiting for the final core configuration of both the ELFR and ALFRED.

17. Docs organization

18. 2010 2011 2012 2013 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 Mil 03 Mil 09 LFR Milestones Task 2.1 Del 05 Del 28 Doc 55 Mil 09 Mil 02 ALFRED Milestones Task 2.2 Del 07 Del 27 Task 2.3 Doc 56 Doc 62 Task 2.4 Doc 54 Doc 60 Task 2.5 Doc 61 Doc 65 Docs timing

19. That’sall, (folks!)

20. Annex I Task 2.1 ELSY review and conceptual ELFR industrial plant neutronic characterization The activities of Task 2.1 will take the move from a critical review of the final FP6 ELSY core configuration, in conjunction with WP1, so as to point out the open issues and possible solutions/strategies to overcome these. A new reference configuration – at conceptual level – of the LFR industrial plant will be then proposed, taking also into account the aim at operating such system as an adiabatic reactor. Two alternative configurations will be also conceived about the reference core (fuelled by reference MOX), at first supposing the fuel is added by an equilibrium content of MA (expected 1.1% on HM), and then assuming all the transuranic elements (TRU) have come to complete equilibrium, as stated by the adiabaticity criterion (expected 1.3% MA on HM). These alternative configurations will be analysed focusing on • the outlining of possible cycle strategies (in conjunction with WP1), evaluating the corresponding flow of wastes and related radiological and thermal loads; and on • the estimation of the impact of the inclusion of MA on the core kinetics, by determining the dependence of the main reactivity coefficients (such as the void effect, the coolant temperature coefficient, the Doppler coefficient and core expansion coefficients) on the abundance of MA in the fuel.

21. Annex I Task 2.2 Criteria for scaling down to the ETDR and its neutronic characterization The preliminary activities of Task 2.2 (in conjunction with WP1) will be focused on the definition of the criteria for the consistency between ALFRED and LFR core parameters, according to the demonstration aims and main goals of the ETDR. The ALFRED core will be characterized neutronically at Beginning of Life (BoL), Beginning of Cycle (BoC) and End of Cycle (EoC), assessing the power distribution, control rods positioning (and strategy), burn up reactivity swing and cycle strategy for the system. Finally, the main reactivity coefficients (such as void coefficient, coolant temperature coefficient, Doppler coefficient and core expansion coefficients) will be evaluated at BoC and EoC, and simplified point kinetic analyses will be performed to investigate the dynamic behaviour of the system to what concerns its stability. Sensitivity analyses of the main core parameters vs nuclear data will be made in order to estimate their contributions to the uncertainties affecting the safety-related and performance coefficients.

22. Annex I Task 2.3 Thermal-hydraulics analysis of the LFR and ETDR The activity of Task 2.3 is the thermal-hydraulic assessment of the cores of both the LFR industrial plant and ALFRED, so as to provide an updated feedback to the fuel pin and fuel assembly design of such systems. In particular, static and transient analyses of the cores will be performed, focused on the identification of possible hot spots – both on the cladding and the fuel – and on the evaluation of natural circulation regimes in case of loss of flow. Task 2.4 Mechanical design and drawings of LFR and ETDR The main activity of Task 2.4 is the mechanical design – up to the production of detailed mechanical drawings – of the fuel pin, fuel assembly and whole core of both the LFR industrial plant and ALFRED, complying with the physical and technological requirements issued by all the Tasks of this Work Package (and WP3).

23. Annex I Task 2.5 DPA and radiological protection for LFR and ETDR Task 2.5 activities are related to the evaluation of the standard damage parameter for nuclear materials, the DPA (displacements/atom), and radiological loads for both the LFR industrial plant and the ETDR. In particular, for the LFR industrial plant the DPA rates will be evaluated in a few of the most critical regions of the main system structures, replaceable or not. For ALFRED, the evaluation of the DPA rates will be performed on the main components of the system, as well as the radiological doses will be evaluated in key positions of the system for personnel radioprotection. The activation estimation will allow also the characterization and the classification of the different components for waste management point of view. The results obtained by this analysis will be used for assessing the design of the shielding structures.

24. Annex II D05 - Reference MOX without MA: definition of the LFR core and neutronic characterization (M 12) This Deliverable reports the reference core configuration for the LFR industrial plant together with its preliminary neutronic characterization, obtained as a result of the critical review of the FP6 ELSY system. This configuration refers to a reactor operating with reference fuel (standard MOX) without MA. D07 - Definition of the ETDR core and neutronic characterization (M 18) This Deliverable reports the ALFRED core configuration, with a complete neutronic characterization to what concerns criticality and power distribution assessment, cycle strategy and related criticality swing, and control rod positioning and operation strategy. D27 - ETDR core. Summary, synoptic tables, conclusions and recommendations (M 36) This Deliverable, intended for public dissemination of the work, collects the main characteristics, features and issues of the final ALFRED core, providing conclusive remarks of the whole activity and recommendations for a further development of the study. D28 - LFR cores. Summary, synoptic tables, conclusions and recommendations (M 36) This Deliverable, intended for public dissemination of the work, collects the main characteristics, features and issues of the proposed core configurations of the LFR industrial plant, providing conclusive remarks of the whole activity and recommendations for a further development of the study.

25. Annex II T54 - Mechanical design and drawings of ETDR pin/assembly/core (M 21) This Technical Document represents the official reference for the ALFRED reactor design, providing to every Task the detailed mechanical drawings of the fuel pin, fuel assembly and whole core. T55 - Adiabatic-LFR (equilibrium MOX with equilibrium MA): preliminary definition of the core and neutronic characterization (M 24) This Technical Document provides the neutronic characterization of the core for the LFR configuration to be operated as an adiabatic reactor. It also reports the impact of the inclusion of MA in the fuel on the main kinetic parameters by means of preliminary dynamic analyses, as well as a preliminary evaluation of the flow of both feed and waste materials in the related closed fuel cycle, together with the results of their radiological and thermal load evaluations. T56 - Thermal-hydraulics assessment of the ETDR core (M 24) This Technical Document provides the results of the detailed static and transient thermal-hydraulic analyses of the ALFRED core to be used for assessing the final configuration of the system. T60 - Mechanical design and drawings of LFR pin/assemblies/cores (M 27) This Technical Document represents the official reference for the different LFR industrial plant designs, providing to every Task the detailed mechanical drawings of the fuel pin, fuel assembly and whole core layout of the LFR configurations.

26. Annex II T61 - ETDR core: DPA rates in the main components, activation, doses (M 27) This Technical Document reports the results of the DPA and radiologic analyses on the main components of the ALFRED system, to be used for assessing the design of the shielding structures. T62 - Thermal-hydraulics assessment of the LFR cores (M 30) This Technical Document provides the results of the detailed static and transient thermal-hydraulic analyses of the industrial LFR cores to be used for assessing the final configurations of the system. T65 - LFR cores: DPA rates in the main components, activation, doses (M 33) This Technical Document reports the results of the DPA analysis on the main components of the industrial LFR system.

27. Annex III