Progress report on the Italian national program on fast reactors

Transcription

1 Progress report on the Italian national program on fast reactors P.Agostini; G.Grasso; M.Angiolini ENEA L.Cinotti - Hydromine Vienna, May

2 Initiatives and collaborations to support LFR 2

3 FALCON consortium In december 2013 the FALCON (Fostering ALfred CONstruction) Consortium was signed among ANSALDO, ENEA and ICN (Romania): to support the contruction of ALFRED through EU structural funds to optimize the cooperation among the PARTIES through strategic, management, governance, financial and technical work In 2014 also CVRez (Czech Republic) adhered the FALCON consortium Several contacts were taken with Romania Government representatives to coordinate the access to European regional funds dedicated to South Muntenia Region In August 2014 the ALFRED Project was included in the draft of Smart Specialization Platform of South Muntenia region The FALCON agreement has been re-newed in June

4 FALCON consortium Recent updates within Falcon Consortium The political situation in Romania is in favor of ALFRED reactor In 2017 Romanian Ministry of Research has announced progressive funds availability for: Construction of Lead technology based preparatory infrastructures and laboratories (minor project) 90M Construction of ALFRED (major project) 700 M ENEA and ANSALDO assured all the support, by in-kind contribution, to write the technical specifications to launch the orders 4

5 Hydromine LFR concept Hydromine is an U.S. based company, very active in the business of energy and mining. It has recently hired a small group of Italian LFR specialists acquiring the rights on their LFR concept. The chief engineer is Luciano Cinotti, formerly ANSALDO, who based his concept mainly on ENEA technology Hydromine officially presented its concept in July 2016 at Imperial College, London. The Hydromine concept is reported in this presentation 5

6 Other LFR collaborations ENEA and Italian companies continue to collaborate with Chinese INEST Institute to CLEAR-S erection GEMMA ENEA started further collaborations on LFR technology with EU and outside EU companies In 2017 a new 4 Meuro EU project, aiming at Gen IV materials, was approved for funding. The project name is GEMMA (GEneration IV Materials Maturity), the coordinator is ENEA. The partnership includes 22 European Institutes + KAERI 6

7 LFR-AS-200 7

8 The Hydromine LFR-AS-200 LFR stands for Lead-cooled Fast Reactor, AS stands for Amphora-Shaped, referring to the shape of the Inner Vessel 200 is the rated electrical power of the reactor in MW. The LFR-AS-200 is based on innovative solutions conceived by the Hydromine team in the last ten years and presented for the first time on July 2016 in London at the Imperial College. Core power (MWth) 480 Electrical power (MWe) 200 Core inlet/outlet T ( C) 420/530 Primary loop pressure loss (bar) 1,3 Table1: Main design parameters of LFR-AS- 200 Secondary cycle Superheated steam Turbine inlet pressure (bar) 180 Feed water /steam temperature ( C) 340/500 L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 8

9 LFR-AS-200, 10 years work for achieving a simple, consistent design LFR-AS-200 is predictably economic Volume of the primary system < 1m 3 /MWe!! ~ 4 times less than SPX1 ~ 2-3 times less than the best SFR projects ~ 3-5 time less than previous LFR projects LFR-AS-200 is feasible Height of the reactor vessel 6,2m!! L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 9

10 The SG of LFR-AS-200 differs from current technology From: long SG deeply immersed in the melt with top inlet window and bottom outlet window. To: short Spiral-tube SG partially raised with respect to the cold collector free level with bottom inlet and top outlet. Advantages: - No risk of steam release deep in the melt and large lead displacements. - No risk of cover gas entrance into the core. - Short, compact SG, reduced RV height. - No Deversoir, reduced RV diameter. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 10

11 The Pump assembly differs from current technology From: Pumps in the cold collector, in-between the SGs, with long shafts and in-melt bearings. To: Pump in the hot collector, integrated in each SG to feed the SG, with large hollow shaft filled with lead, and no in-melt bearings. Advantages: - Use of available space inside the SG, reduced RV diameter. - No bearings in lead. - High mechanical inertia for mild transients from forced to natural circulation. - Core fed by the hydrostatic head Δh between cold and hot collector, no LIPOSO L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 11

12 The issue of refueling the LFR. Refueling is difficult in sodium: - Both Jōyō and Monju in Japan are at shutdown because of handling accidents. - Need of a complicate in-vessel refueling machine. - Need of complicate preparatory interventions. In-lead refueling is even more difficult: - Higher refueling temperature. - Large buoyance effect. Above Core Structure to be moved for refueling L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 12

13 The Fuel Assembly of LFR-AS-200 differs from current technology From: Fuel Assemblies immersed in the melt handled by an in-vessel + ex-vessel Refueling Machine. To: Fuel Assemblies with stem extended above the lead free level handled by an ex-vessel Refueling Machine. Advantages: - No in-vessel Refueling Machine, reduced RV diameter. - No Above Core Structure, reduced RV diameter. - Buoyance compensated by the emerged portion of the stem. - Increased reliability. A cold handle allows easy handling in hot oil. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 13

14 The issue of ISI of the core support system The classical core support structures, Diagrid and Strongback, are critical components subjected to thermal transients and neutron damage. Their collapse could bring about effects of control rod extraction. Their ISI is difficult in sodium because of deep location and complexity. Their ISI in lead would be even more difficult. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 14

15 The Core of the FR-AS-200 is self-sustaining From: Fuel Assemblies (FA) supported in lead at the bottom by Diagrid and Strongback. To: Core anchored at the top to a barrel in gas space. Advantages: - No Diagrid. - No Strongback. - No support system subject to thermal transients and neutron damage (only disc cams integral part of the FAs). - No need of disconnecting all FAs instrumentation at refueling. - Increased availability. Cams L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 15

16 The Amphora-Shaped Inner Vessel From: Inner Vessel, large at top and smaller at bottom, containing Shielding Assemblies (and Breeding Assemblies). To: Amphora-Shaped Inner Vessel, no Shielding Assemblies (and no Breeding Assemblies). Advantages: - No need of Shielding Assemblies, reduced RV diameter, increased availability, reduced waste inventory. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 16

17 The ex-core control rods From: In-core control and shut down rods. To: Ex-core control and shut down rods. Advantages: - Reduced core dimensions. - No disconnection of rod drives for refueling. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 17

18 Resistance to cyber attacks Logics and operators backed up by passively actuated systems to shut down the reactor. In a LFR there is a margin of hundreds K between the operating temperature and the safety limit, hence, e.g., thermal expansion can be used to open the core and shut down the reactor in case of failure of logics or of operator intervention. Bi-metallic expansors open and shut down the core when temperature exceeds normal operating limits. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 18

19 Resistance to cyber attacks 2/2 Passive shut down is complemented by two independent, passive, diverse, redundant DHR systems to face the Unprotected Loss Of Offsite Power (ULOOP). DHR1:Three water-steam loops passively operated with water as heat sink. DHR2: Three lead loops passively actuated and operated with air as heat sink. Chimney Louvers Air cooler Lead loop d Lead-water, double-wall bayonet-tube bundle heat exchanger at Brasimone site. Thermal expansion of the cold leg of the lead loop opens the louvers of the air coolers when lead temperature exceeds 400 C. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 19

20 Conclusion 1 LFR-AS-200 enhances safety while dispensing of hitherto classical critical components Components/systems no more needed Rationale for elimination Impact Intermediate loop Lead properties. Compact Reactor Building, easy operation, cost reduction (about 30% of the cost of NSSS in a SFR). Above core structure Use of FAs with extended Reduced diameter of the RV, no need stem. of its displacement for refuelling. In-vessel refuelling machine Use of FAs with extended stem. Elimination of a mechanically critical component to be operated in opaque medium. Reduced diameter of the RV, reduced vibration risk. Deversoir or equivalent component SG-outlet window at top of the SG. Diagrid Self-sustaining core. No need of a component difficult to inspect. Strongback Core supported by the roof via the barrel. No need of a component difficult to inspect. No structure fixed to the RV LIPOSO, hydraulic connection pump to diagrid Pumps in the hot collector. Elimination of a mechanically critical component. Pump bearings in lead Low required NPSH for the pumps. Elimination of a mechanically critical component. Flywheel on the pump system Use of rotating lead inertia. Smaller footprint on the reactor roof. Core shielding assemblies Use of the ASIV. Reduced diameter of the RV, simplicity. Blanket assemblies No net Pu generation. Reduced diameter of the RV, simplicity, increased proliferation resistance. L. Cinotti, Hydromine Nuclear Energy Limited - Novelty of the LFR-AS-200 project 20

21 Materials studies 21

22 GEMMA GEMMA Project Challenge: resolving the key remaining issues regarding structural (and fuel materials) to be used in Generation-IV reactor concepts under consideration in the EU Keywords: materials and joints under neutron irradiation, high temperature, compatibility with coolants (and advanced fuels), physical models and/or modelling-oriented experiments, microstructural change and effects on material properties, advanced micro-structural characterisation techniques, mitigation strategies surface engineering concepts Impact: predictive capability, design codes, overcome bottlenecks of certification of materials, contribute to safety improvements also in other nuclear systems 22

23 GEMMA Proposed structure focus on 316L(N) & 15/15Ti Proposed structure focus on 316L(N) & 15/15Ti LFR, GFR WP1-Surface engineering & its basic characterisation A.Weisenburgerr MITIGATION Base material selection and procurement SFR, LFR (GFR) WP2-Welding & its relevant characterisation K.Tucek DESIGN RULES SFR (LFR, GFR) WP3-Irradiation effects: modelling and experiments M.Nastar MODELLING & µstructure DESIGN RULES LFR, GFR WP4-Compatibility with high T coolant: Corrosion/erosion testing & modelling E. Stergar MODELLING & µstructure WP5-Coordination and dissemination (communication & exploitation of results) P. Agostini 23

24 GEMMA Support to MYRRHA Corrosion tests in LBE of AISI 316L, AISI316LN and 15-15Ti MYRRHA, Corrosion of: welded joints of above steels by TIG & SAW, AFA steels and coated steels. Mechanical qualifications in LBE of the above steels by: SSRT, fracture toughness, creep rupture Corrosion modeling in HLM Lead-Bismuth coolant 24

25 GEMMA Support to ALFRED Corrosion tests in Pb of AISI 316L, AISI316LN and 15-15Ti ALFRED, Corrosion of: welded joints of above steels by TIG & SAW, AFA steels and coated steels. Mechanical qualifications in Lead of the above steels by: SSRT, fracture toughness, creep rupture Corrosion modeling in HLM 25

26 GEMMA Support to ASTRID Theoretical studies, models and tests of diffusion aging by annealing and ion irradiation in Fe-Ni-Cr systems. Detailed qualification of large thickness AISI 316LN welds through measurement of residual stresses by neutron diffraction and modelling 26

27 GEMMA Support to ALLEGRO Mechanical qualification at 550C of AISI 316L welded joints by TIG and SAW: SSRT Fracture toughness Creep rupture Mechanical qualification at 550C of AISI 316L Al2O3 coated SSRT Creep Rupture Swelling qualification under ion irradiation of coated AISI 316L Low damage qualification under neutron irradiation of coated AISI 316L 27

28 Conclusions Recent changes in the Romanian political situation offered important chances to fund the ALFRED initiative In the frame of FALCON consortium. This new fact is boosting the LFR activities by ENEA and ANSALDO as well. Hydromine US based company has recently acquired rights for an innovative LFR by an Italian group of engineers and designers formerly in ANSALDO. The Hydromine project LFR-AS-200 presents innovative design features and relies on technologies developed by ENEA ENEA coordinates a new EU project focused on structural materials for GEN IV reactors. The project includes 22 research institutes and industries from: Italy, Belgium, Germany, France, Finland, U.K., Spain, Czech Republic, Sweden, Poland, Romania and Korea. The ongoing international collaborations by ENEA and ANSALDO are: in the European frame with Romanian ICN and Czech CVRez with Chinese Academy of Sciences with US companies with Russian institutes 28