Design of Lithium-Lead/Water interaction experiments relevant to WCLL breeding blanket in-box LOCA

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UNIVERSITÀ DI PISA

DIPARTIMENTO DI INGEGNERIA CIVILE E INDUSTRIALE

CORSO DI LAUREA MAGISTRALE IN INGEGNERIA NUCLEARE

Design of Lithium-Lead/Water interaction

experiments relevant to WCLL breeding blanket

in-box LOCA

Relatori

Candidato

Prof. Ing. Nicola Forgione

Prof. Ing. Walter Ambrosini

Matteo Ghisti

Dr. Ing. Alessandro Del Nevo

Dr. Ing Marica Eboli

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ABSTRACT

The present thesis work was performed during an internship of six months at ENEA Brasimone Research Center. The objective has been focused on the design of the experiments relevant for the validation of SIMMER-III code, and in particular of the lithium lead water reaction chemical model implemented in the code.

Lithium lead alloy is used in Water-Cooled Lithium-Lead Breeding Blanket, which is a candidate for DEMO fusion power plant. The conceptual design of the DEMO is developed under the supervision and coordination of the EUROfusion Consortium Agreement.

The water coolant system is characterized by horizontal tubes placed in the liquid Lithium Lead. Notwithstanding these are double walled, the probability of a water tube rupture is not negligible, thus the “in box LOCA” accident is of major relevance. Indeed, this implies the interaction between high temperature (about 300°C) and high pressure (15.5MPa) coolant water and high temperature PbLi (> 330 °C), which will cause release of energy in the breeding zone, due to the thermal and chemical reaction and the hydrogen generation. The review of past R&D activities has highlighted that no code is capable to perform a deterministic analysis of the “in box LOCA” postulated accident. Analogously past experimental activities are not suitable to validate predictive computational tools. In view of this, ENEA has proposed a R&D activity, lasting five years, aimed at setting-up a computer code suitable to simulate the phenomena relevant to safety occurring during the lithium lead water interaction; and at designing and executing the experimental campaign to generate data for code validation in the LIFUS5/Mod3 facility.

The activity has been pursued working on the implementation of the experiment and design of as well as on the numerical simulations with SIMMER-III code, making pre-test calculations, to support the design of the test matrix and the testing procedures.

At the end of the activity, the conceptual design of test section B has been developed, the hydrogen extraction line and analysis system have been designed by means of SIMMER-III and RELAP5/Mod3.3 codes and the SIMMER-III nodalization of LIFUS5/Mod3 test section was used to make pre-test calculation to determine test conditions for two experimental campaigns: the former campaign is aimed to validate the SIMMER-III chemical interaction model, the latest is focused on validating the global reaction/interaction model.

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SOMMARIO

Questa attività di Tesi è stata condotta prevalentemente durante un periodo di tirocinio di sei mesi presso il Centro Ricerche ENEA del Brasimone ed ha come obbiettivo il supporto alla progettazione di esperimenti rielevanti per la validazione del codice di calcolo SIMMER, ed in particolare del modello chimico relativo alla reazione tra PbLi ed acqua. La lega piombo litio è utilizzata nel “Water-Cooled Lithium-Lead Breeding Blanket”, che rappresenta uno dei candidati per il “blanket” di DEMO. Il design concettuale del reattore a fusione dimostrativo DEMO è sviluppato sotto la guida del Consorzio EUROfusion.

Il sistema di raffreddamento è caratterizzato da tubi orizzontali immersi nella lega di piombo litio. Nonostante i tubi di riferimento del refrigerante siano a doppia parete, l’incidente “in-box LOCA”, avente come evento iniziatore la rottura di uno di questi tubi non è trascurabile. In questo caso, l’interazione tra refrigerante ad alta temperatura (circa 300°C) ed alta pressione (15.5MPa) e la lega di PbLi ad alta temperatura (> 330°C) implica un rilascio di energia all’interno della zona di “breeding”, causato dalla reazione termica e chimica e dalla conseguente formazione di idrogeno.

La revisione bibliografica delle attività di R&D sull’argomento ha evidenziato la mancanza di codici di calcolo per l’analisi deterministica dello scenario incidentale di “in-box LOCA”, così come la necessità di esperimenti progettati per la validazione di tali strumenti di calcolo. Per questa ragione, ENEA ha proposto un’attività di ricerca della durata di 5 anni finalizzata allo sviluppo di un codice di calcolo capace di simulare i fenomeni rilevanti per la sicurezza dovuti all’interazione tra l’acqua e il metallo liquido ed alla validazione attraverso la progettazione e l’esecuzione di una campagna sperimentale nell’impianto LIFUS5/Mod3.

L’attività si è svolta su due piani prevalenti: il primo, sperimentale, relativo al supporto fornito per la scelta di alcuni strumenti di misura, per il dimensionamento di alcuni componenti come i cavi scaldanti e i dispositivi di iniezione, per l’esecuzione delle fasi di montaggio dell’impianto; il secondo, numerico, attraverso l’utilizzo di strumenti di calcolo, come SIMMER-III, implementando calcoli di pre-test rilevanti per la progettazione della test matrix e la scelta delle procedure di prova.

Alla fine del presente lavoro è stato sviluppato il design concettuale della sezione di prova B, è stata progettato il sistema di estrazione e analisi dell’idrogeno attraverso i codici SIMMER-III e RELAP5/Mod.3.3 ed inoltre è stata implementata una nodalizzazione della facility LIFUS5/Mod3 e utilizzata per calcoli di pre-test, al fine di definire le condizioni di prova per due campagne sperimentali: la prima con lo scopo di validare il modello chimico del SIMMER-III, la seconda per la validazione del modello di interazione globale, ovvero degli andamenti di temperatura e pressione.

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NOMENCLATURE

BB Breeding Blanket

BIC Boundary and Initial Condition

BLAST BLAnkety Safety Test

BZ Breeding Zone

CAD Computer-Aided Design

CCI Coolant Coolant Interaction

CEA French Atomic Energy Commission

DCLL Dual Cooled Lithium Lead

DEMO DEMOnstration Power Plant

DICI Dipartimento di Ingegneria Civile e Industriale

DP Differential Pressure Transducer

ENEA Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile

EoPh End of Phase

EOS Equation of State

EoT End of Transient

EU European Union

FCI Fuel Coolant Interaction

FW First Wall

HCLL Helium Cooled Lithium Lead

HCPB Helium Cooled Pebble Bed

HEFUS3 Helium Fusion Loop

HYDREX Hydrogen Extraction

HLM Heavy Liquid Metal

HTC Heat Transfer Coefficient

IELLLO Integrated European Lead Lithium Loop

IFA InterFacial Area

ITER International Thermonuclear Experimental Reactor

JNC Japan Power Reactor and Nuclear Fuel Development Corporation

JRC Joint Research Centre

LIFUS Lithium Fusion

LOCA Loss of Coolant Accident

LMFR Liquid Metal Fast Reactor

LWR Light Water Reactor

MHD Magneto Hydro Dynamic

MIT Massachusetts Institute of Technology

PbLi Lithium Lead alloy

PC Absolute Pressure Transducer

P&ID Plan and Instrumentation Diagram

PHTS Primary Heat Transfer System

PMU Program Management Unit

PPPT Power Plant Physics and Technology

PR Poloidal-Radial

PT Dynamic Pressure Transducer

PWR Pressurized Water Reactor

R&D Research and Development

RELAP Reactor Loss of coolant Analysis Program

SC Superconducting Coils

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SoT Start of Transient

TC Thermocouple

TF Toroidal Field

THALLIUM Test Hammer In Lead Lithium

TR Toroidal-Radial

TRIEX Tritium Extraction

UNIPI Università di Pisa

US United States

VV Vacuum Vessel

WCLL Water Cooled Lithium Lead

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LIST OF FIGURES

Fig. 1.1 – EUROfusion DEMO CAD model 2015: 3D isometric view with WCLL BB

primary system (Ref.[3]). ... 2

Fig. 1.2 – BB under investigation for DEMO (Ref.[7]-[10]). ... 4

Fig. 1.3 - Section of the breeding cell element on toroidal-radial plane (Ref.[3]). ... 5

Fig. 1.4 – Section of a poloidal plane of a breeding cell (Ref.[3])... 6

Fig. 1.5 – 3D view of BZ and FW inlet and outlet manifold (Ref.[3]). ... 6

Fig. 1.6 – Stiffening plates on a WCLL BB module (Ref.[3]). ... 7

Fig. 2.1 – Lithium-lead alloy/water interaction (Refs. [9],[25]). ... 13

Fig. 2.2 – H2 production rate for H2O-Pb83Li17 reaction (Ref.[27]). ... 14

Fig. 2.3 – Pressure trend at 0.1 MPa injection (Ref.[10]) ... 14

Fig. 2.4 – Pressure trend at 2 MPa injection (Ref.[10]) ... 14

Fig. 2.5 – Specific mechanical energy as a function of the subcooling (Ref.[10]). ... 15

Fig. 2.6 – Overview of BLAST facility (Ref.[11]). ... 16

Fig. 2.7 – BLAST Test#5: identification of the different phenomenological windows in the reaction vessel pressurization (Ref.[11]) ... 16

Fig. 2.8 – P&ID of LIFUS5 facility ... 17

Fig. 2.9 – LIFUS5 experimental campaign: experimental trends (Refs.[20]-[21]). ... 18

Fig. 2.10 – SIMMER-III code simulations of first peak of BLAST tests (Ref.[18]). ... 20

Fig. 2.11 – SIMMER-III code results vs BLAST Test#5 experimental data: pressure trends in reaction and expansion vessels (Ref.[21]). ... 20

Fig. 2.12 – SIMMER-III code results vs LIFUS5 experimental data: pressure trends in reaction and expansion vessels (Ref.[20]). ... 21

Fig. 3.1 – SIMMER-III overall code structure (Ref.[1]). ... 24

Fig. 3.2 – SIMMER-III geometric framework (Ref.[1]). ... 25

Fig. 3.3 – Pool flow regime map in SIMMER-III (Ref.[1]). ... 27

Fig. 3.4 – Schematic concept of separating bubbly and dispersed regions (Ref.[1]) ... 27

Fig. 3.5 – Channel flow regime map in SIMMER-III. ... 27

Fig. 3.6 – Material composition at the end of simulations. ... 29

Fig. 3.7 – SIMMER-III nodalization of LIFUS5 reaction vessel. ... 30

Fig. 3.8 – Pressure trends of reference case in reaction vessel. ... 30

Fig. 4.1 – LIFUS5/Mod3 test section B P&ID. ... 37

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Fig. 4.3 – S1_B reaction vessel and penetrations. ... 39

Fig. 4.4 – Section view of S1_B vessel ... 40

Fig. 4.5 – Lateral view of S4_B1 ... 41

Fig. 4.6 – Lateral view of S4_B2 ... 42

Fig. 4.7 – S4_B1 and S4_B2 PbLi storage tanks ... 43

Fig. 4.8 – Details of the storage tank with instrumentation and heating wire details. ... 43

Fig. 4.9 – Injection valves ... 44

Fig. 4.10 – Zoom of injection system ... 45

Fig. 4.11 – Water and PbLi Injection system ... 46

Fig. 4.12 – Calibrated protective cap ... 46

Fig. 4.13 - Injector ... 47

Fig. 4.14 – Scheme of protective cap test section. ... 47

Fig. 4.15 – Heated section for rupture tests... 48

Fig. 4.16 – Pressurization system for rupture tests. ... 48

Fig. 4.17 – Pressure time trend for T#10. ... 49

Fig. 4.18 - SIMMER-III pre-tests: material composition and temperature maps during the transient. ... 51

Fig. 4.19 – LIFUS5/Mod3: TS design and arrangement of the TC in S1_B. ... 52

Fig. 4.20 – Case #11: pressure trends. ... 55

Fig. 4.21 – Case #11: volumetric flow rates (zoom 0 – 2s). ... 55

Fig. 4.22 – Case #11: volumetric flow rates. ... 56

Fig. 4.23 – Case #11: gas temperature trends. ... 56

Fig. 4.24 – RELAP5 nodalization of injection line. ... 57

Fig. 4.25 – Siemens CALOMAT 6 principle of operation (Ref.[16]). ... 59

Fig. 4.26 – Siemens CALOMAT 6 offset procedure. ... 59

Fig. 4.27 – P&I of the hydrogen system measurement. ... 60

Fig. 4.28 – Power calculation data. ... 61

Fig. 4.29 – VP-S4B-01/VP-S4B-02 PbLi charging/discharging valves ... 63

Fig. 4.30 – Melting furnace of PbLi. ... 64

Fig. 4.31 – LIFUS5/Mod3 synoptic. ... 65

Fig. 4.32 – Vegaflex 86 level meter. (Ref.[11]) ... 68

Fig. 4.33 – Kyowa KHC strain gauge functional scheme (Ref.[13]) ... 69

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Fig. 4.35 – Principle of operation of DP meters (Ref.[14]). ... 71

Fig. 4.36 – Pressure transducers. ... 72

Fig. 4.37 – Rheonik RHM 15 mass flow meter. (Ref.[9]) ... 73

Fig. 4.38 – Accuracy of Rheonik Coriolis flow meter. (Ref.[9]) ... 73

Fig. 4.39 – Edwards RV8 two stage rotary vane pump (50Hz). (Ref.[8]) ... 74

Fig. 4.40 – Speed curve for three gas ballast mode (50Hz). (Ref.[8]) ... 74

Fig. 4.41 – Rupture disk (Ref.[17]). ... 75

Fig. 4.42 – Disk holder (Ref.[18]). ... 75

Fig. 5.1 – LIFUS5/Mod3 test section holed plate design. ... 78

Fig. 5.2 – SIMMER-III modeling of LIFUS5/Mod3 facility. ... 81

Fig. 5.3: SIMMER-III modeling. Zoom on S1_B reaction vessel and reference mesh cells. ... 82

Fig. 5.4 – SIMMER-III modeling. Zoom on the injection line and orifice coefficients. ... 82

Fig. 5.5 – SIMMER-III BFCAL nodalization of LIFUS5/Mod3 facility. ... 83

Fig. 5.6 – L5M3_Case#1: calculated pressure (PK) in the injection line at different positions (zoom 0 – 1.0 s). ... 88

Fig. 5.7 – L5M3_Case#1: pressure (PK) and temperature of Argon gas (TGK) between the gas cylinder and the beginning of the injection line imposed as BIC (zoom 0 – 100 ms). ... 89

Fig. 5.8 – L5M3_Case#1: calculated pressure (PK) and temperature of water (TLK3) in the injection line (zoom 0 – 100 ms). ... 89

Fig. 5.9– L5M3_Case#1: calculated pressure (PK) and temperature of water (TLK3) at the injector device (zoom 0 – 100 ms). ... 90

Fig. 5.10 – L5M3_Case#1: calculated volume fraction of water (ALPLK3) and vapor (ALPGK) at the injector device. (Zoom 0 – 100 ms). ... 90

Fig. 5.11 – L5M3_Case#1: pressure trends in S1_B reaction vessel. ... 91

Fig. 5.12 – L5M3_Case#1: pressure trends in S1_B reaction vessel. (Zoom 0 – 1.0 s). ... 91

Fig. 5.13 – L5M3_Case#1: water mass flow rate and hydrogen production. (Zoom 0 – 1.0 s). ... 92

Fig. 5.14 – L5M3_Case#1: integral water mass flow rate. ... 92

Fig. 5.15 – L5M3_Case#1: calculated hydrogen generation (MASFPG) in different macro-regions (S1_B, Cover Gas, Extraction lines). ... 93

Fig. 5.16 – L5M3_Case#1: evaluation of gas (BFLUXG) and hydrogen mass flow rate through the injector. ... 93

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Fig. 5.18 – L5M3_Case#1: mass of water (MASN1) in different macro-regions. ... 94 Fig. 5.19 – L5M3_Case#1: mass of vapor (MASN2) in different macro-regions. ... 95 Fig. 5.20 – L5M3_Case#1: PbLi temperature (TLK1) at different radial position and

bottom level. (Zoom on 0 – 1 s). ... 95 Fig. 5.21 – L5M3_Case#1: PbLi temperature (TLK1) at different radial position and

middle level. (Zoom on 0 – 1 s). ... 96 Fig. 5.22 – L5M3_Case#1: PbLi temperature (TLK1) at different radial position and

top level. (Zoom on 0 – 1 s). ... 96 Fig. 5.23 – L5M3_Case#1: Material composition and temperature maps during the

transient. ... 98 Fig. 5.24 – Sensitivity analyses: influence of amount of injected water - pressure

trends in S1_B reaction vessel. ... 100 Fig. 5.25 – Sensitivity analyses: influence of amount of injected water - pressure

trends in S1_B reaction vessel (focus on 0 – 1 s). ... 101 Fig. 5.26 – Sensitivity analyses: influence of amount of injected water - water mass

flow rate at the injector device and hydrogen production. ... 101 Fig. 5.27 – Sensitivity analyses: influence of amount of injected water - water mass

flow rate at the injector device and hydrogen production (focus on 0 – 1 s). ... 102 Fig. 5.28 – Sensitivity analyses: influence of amount of injected water – maximum

PbLi temperature trends (focus on 0 – 2 s). ... 102 Fig. 5.29 – Sensitivity analyses: influence of water temperature - pressure trends in

S1_B reaction vessel... 104 Fig. 5.30 – Sensitivity analyses: influence of water temperature - pressure trends in

S1_B reaction vessel (focus on 0 – 1 s). ... 104 Fig. 5.31 – Sensitivity analyses: influence of water temperature - water mass flow

rate at the injector device and hydrogen production (focus on 0 – 1 s). ... 105 Fig. 5.32 – Sensitivity analyses: influence of water temperature - selected

temperature trends (focus on 0 – 2 s). ... 105 Fig. 5.33– Sensitivity analyses: influence of orifice diameter - pressure trends in

S1_B reaction vessel (focus on 0 - 2.5 s). ... 107 Fig. 5.34 – Sensitivity analyses: influence of orifice diameter - water mass flow rate

at the injector device and hydrogen production (focus on 0 – 3 s). ... 108 Fig. 5.35 – Sensitivity analyses: influence of orifice diameter – injected water (focus

on 0- 2.5 s). ... 108 Fig. 5.36 – Sensitivity analyses: influence of orifice diameter – maximum PbLi

temperature trends (focus on 0 – 2 s). ... 109 Fig. 5.37 – L5M3_Case#1bis: nodalization of facility. ... 111

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Fig. 5.38 - L5M3_Case#1bis: calculated pressure (PK) in the injection line at different positions (Zoom 0 – 5 s). ... 114 Fig. 5.39 - L5M3_Case#1bis: calculated pressure (PK) and temperature of water

(TLK3) in the injection line (Zoom 0 - 2 s). ... 115 Fig. 5.40 - L5M3_Case#1bis: calculated pressure (PK) and temperature of water

(TLK3) at the injector device. (Zoom 0 - 2 s). ... 115 Fig. 5.41 - L5M3_Case#1bis: calculated volume fraction of water (ALPLK3) and

vapor (ALPGK) at the injector device (Zoom 0 – 2 s). ... 116 Fig. 5.42 - L5M3_Case#1bis: pressure trends in S1_B reaction vessel. ... 116 Fig. 5.43 - L5M3_Case#1bis: pressure trends in S1_B reaction vessel (Zoom 0.4 –

1.5 s) ... 117 Fig. 5.44 - L5M3_Case#1bis: water mass flow rate and hydrogen production (zoom

0 – 6 s). ... 117 Fig. 5.45 – L5M3_Case#1bis: integral water mass flow rate. ... 118 Fig. 5.46 - L5M3_Case#1bis: calculated hydrogen generation (MASFPG) in different

macro-regions (S1_B, Cover Gas, Extraction lines). ... 118 Fig. 5.47 - L5M3_Case#1bis: PbLi mass flow rate (BFLUXF) through the injector. ... 119 Fig. 5.48 - L5M3_Case#1bis: mass of water (MASN1) in different macro-regions

(zoom 0 - 7 s). ... 119 Fig. 5.49 - L5M3_Case#1bis: mass of vapor (MASN2) in different macro-regions

(zoom 0 - 7 s). ... 120 Fig. 5.50 - L5M3_Case#1bis: PbLi temperature (TLK1) at different radial position

and bottom level (Zoom on 0 – 3 s). ... 120 Fig. 5.51 - L5M3_Case#1bis: PbLi temperature (TLK1) at different radial position

and middle level (Zoom on 0 – 3 s). ... 121 Fig. 5.52 - L5M3_Case#1bis: PbLi temperature (TLK1) at different radial position

and top level (Zoom on 0 – 3 s). ... 121 Fig. 5.53 – L5M3_Case#1bis: Material composition and temperature maps during

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LIST OF TABLES

Tab. 1.1 – Main plasma parameters for DEMO 2015 concept (Ref.[4]). ... 3

Tab. 2.1 – Main phenomena related to vapor explosions (Ref.[3]). ... 11

Tab. 2.2 – LIFUS5 experimental test relevant parameters ... 18

Tab. 3.1 – Suggested PbLi properties (Ref.[20]). ... 32

Tab. 4.1 – First experimental campaign test matrix ... 36

Tab. 4.2 – Second experimental campaign test matrix ... 36

Tab. 4.3 – Tanks S1_B, S4_B1, and S4_B2 geometrical features. ... 39

Tab. 4.4 – S1_B instrumentation. ... 40

Tab. 4.5 – S4_B1 instrumentation. ... 41

Tab. 4.6 – S4_B2 instrumentation. ... 42

Tab. 4.7 – Data characterizing the protective cap tests. ... 49

Tab. 4.8 – Ar data at t=0 ... 53

Tab. 4.9 – H2 data at the end of test ... 53

Tab. 4.10 – Summary of calculation results. ... 54

Tab. 4.11 – Installed heating wires. ... 62

Tab. 4.12 – Installed thermocouples. ... 68

Tab. 4.13 – Installed level meters. ... 68

Tab. 4.14 – Installed strain gauges. ... 70

Tab. 4.15 – Installed DP meters. ... 71

Tab. 4.16 – Installed pressure transducers... 72

Tab. 5.1 – Summary of orifice coefficients of injection line ... 79

Tab. 5.2 – SIMMER-III LIFUS5/Mod3 model: correspondence of main dimensions. ... 83

Tab. 5.3 – Performed tests. ... 84

Tab. 5.4 – L5M3_Case#1: comparison between design and calculated values at the initial conditions. ... 85

Tab. 5.5 – L5M3_Case#1: thermal-hydraulic conditions of water at the injection time. ... 85

Tab. 5.6 – L5M3_Case#1: phenomenological analysis. ... 88

Tab. 5.7 – Sensitivity analyses: influence of amount of injected water - main parameters characterizing the calculations. ... 100

Tab. 5.8 – Sensitivity analyses: influence of temperature - main parameters characterizing the calculations. ... 103

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Tab. 5.9 – Sensitivity analyses: influence of orifice diameter - main parameters characterizing the calculations. ... 107 Tab. 5.10 - LIFUS5/Mod3 nodalization: Case#1bis. ... 112 Tab. 5.11 - L5M3_Case#1bis: thermal-hydraulic conditions of water at the injection

time. ... 112 Tab. 5.12 - L5M3_Case#1bis: phenomenological analysis. ... 113 Tab. 5.13 - L5M3_Case#1bis: main parameters characterizing the calculations. ... 114

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