1. Task 2.1: Review of ELSY and Conceptual design & neutronic characterization of the ELFR Industrial Plant Kamil Tuček on behalf of Task 2.1 contributors Joint Research Centre (JRC) Institute for Energy and Transport (IET) Nuclear Reactor Safety Assessment Unit (NRSA) http://iet.jrc.ec.europa.eu LEADER WP2 Meeting Karlsruhe, 21 November 2012

2. 2 Define an updated core configuration for the European LFR Industrial Plant, starting from a critical review of the previous ELSY core and aiming at the demonstration of the so called “adiabatic” concept, which envisages multi-recycling of the entire actinide vector until an equilibrium is achieved with a top-up material being natural or depleted uranium and removed materials being FPs and actinides not recovered or lost in reprocessing & fuel fabrication The second objective is to design and characterise ELFR start-up cores and devise possible strategies for the transition from start-up to equilibrium (adiabatic) cores Investigate MA burning capability of ELFR cores for MA concentrations beyond those corresponding to self-produced nuclei The detailed objectives of Task 2.1 are to 24 January, 2016

3. 3 ANSALDO 1 PM AGH 6 PM ENEA 8 PM KIT 6 PM INR 5 PM JRC 5 PM We’re six partners D05: Definition of the adiabatic equilibrium ELFR core and its neutronics characterization (technically completed) T55: Design and neutronic characterisation of start-up core, its MA burning capability, and on scenarios of its possible transition to the adiabatic equilibrium (activities are on-going) D28: Summary, conclusions and recommendations on the ELFR core configurations (with deadline on 31 March 2013) With two deliverables and one technical report

4. It’s scope-wise completed and includes contributions from AGH, ENEA, KIT, and JRC Internal review at JRC had been performed and draft revision A was distributed by Christoph Döderlein to other partners for review and comments on September 21 st Updates and comments were received from KIT and ENEA Rev. A is envisaged to be published in December 2012, possibly also including comments from AGH Status of Deliverable D05 is as follows 24 January, 20164

5. A. Travleev 24 January, 20165 Specifically at KIT, two model improvements were implemented Explicit heterogeneous modelling of wrapper structures and coolant in the SA inlet and outlet regions assuming thus more realistic amount of steel in these parts of the model, which is about 10%. This is to be compared to 50% assumed in the old, original homogeneous model.

6. 624 January 2016 Consequently, impact of these model changes on the system criticality and reactivity feedbacks, specifically coolant density reactivity feedback was investigated A. Travleev The second improvement implemented concerns Improved design of radial shield assemblies, which are now modelled more realistically (like sub-assemblies) instead being modelled in an ad-hoc, customised manner

7. Change in the model k eff (value / change) at BoLBoCEoC Original model0.99460 / 01.00212 / 01.00469 / 0 Lower nozzles0.99447 / -131.00220 / 81.00427 / -42 Lower and upper nozzles0.99994 / 5341.00756 / 5441.00981 / 512 Nozzles and shield assemblies 1.00066 / 6061.00846 / 6341.01053 / 584 with estimated standard dev. of about 4 pcm There is about 500 pcm contribution to the increase of k eff due to the change in SA outlet modelling, the reason being mainly lower neutron capture While contribution of ca. 80 pcm to the increase of k eff was observed from the change of modelling of the radial shield assemblies On the other hand, k eff changes only negligibly due to the change of the model at the SA inlet Due to lower absorption in the reflector (SA inlet and outlet regions) k eff increases 7 In terms of the impact on the criticality (k eff )

8. Region RC (value / change) at BoLBoCEoC In-core -418 ± 5 / -410±4-425 ± 5 / -396 ± 4-411 ± 5 / -401 ± 4 Inlet 17 ± 1 / 19 ± 218 ± 1 / 11 ± 214 ± 1 / 15 ± 2 Outlet22 ± 1 / 38 ± 527 ± 1 / 54 ± 525 ± 1 / 33 ± 4 It was observed that the updated model yields slightly smaller coolant density reactivity coefficient, including the corresponding value for the in- core region, than the original model Generally speaking, however, the impact of the new implemented model on the predictions of core criticality and reactivity coefficients seems to be rather small 8 As for the impact on the coolant density reactivity coefficient / RC (k/)

9. Design and characterise start-up ELFR core with MOX fuel Analyse impact and investigate potential for MA burning, incl. initial MA loadings beyond those corresponding to self-produced MAs Devise preliminary strategies for the transition from start-up to adiabatic equilibrium core Regarding the Technical Report T55, the activities to be reported there have objectives to: 24 January, 20169 Contribution is expected also from AGH Original expected delivery was on 30 April 2012  Now? Contribution is expected also from AGH Original expected delivery was on 30 April 2012  Now?

10. 1024 January, 2016 Should provide, on the basis of results of Deliverable D05 and Technical Report T55, summary, conclusions and recommendations on further improvements of the ELFR core configuration Has delivery date on 31March 2013 Contributions are expected from JRC (main author) and ENEA with a possible review role of ANSALDO One of the aspects to be highlighted for the improvement is the low average discharge burn-up (~50 GWd/t HM ) achieved in the present ELFR core concepts (which is, among others, due to the absence of fuel reshuffling) Deliverable 28:

11. Conclusions Rev. A of Deliverable D05 is to be issued in December 2012, to possibly also include review and comments from AGH Contributions to Technical Report T55 are expected mainly from AGH, status of activities is to be clarified Deliverable D28 shall be issued by 31 March 2013, with contributions expected from JRC and ENEA and with possible ANSALDO contribution to review and comment on the report, at the same time ensuring coherence with the conclusions and recommendations reached in other WPs 1124 January, 2016

12. 12 Thank you for your attention!