Sodium corrosion studies in support of SFR : state of

GROUPEMENT DE RECHERCHE CEA - CNRS - EDF - AREVA NP

3rd International Topical Seminar JAEA / CEA on Coolant and Innovative Reactor Technologies

Sodium corrosion studies in support of SFR : state of the art CEA / DEN / Saclay DPC / SCCME : Behaviour of materials in nuclear, industrial, natural and biological environments, from the understanding of elementary processes up to the development of predictive integrated models for industrial applications, permanents staff : >60, PhD >15 , Lab. > 4000 m² LECNA : J-L. Courouau, V. Lorentz, F. Balbaud

DEN-DPC-SCCME - LECNA

Reproduction or diffusion prohibited without CEA authorization

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Plan

1- Introduction 2- Short literature review 3- R&D programme 4- Testing device design 5- Prospect and others issues



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Introduction

1

• Excellent compatibility of steel with pure liquid sodium, specifically the austenitic steels used in the reactors built up to today in their given operating conditions • Context : new needs for the 2020 SFR prototype or for the SFR (materials // operating conditions // alternative coolant for secondary circuit or for energy conversion systems) Components

Materials

Normal operating conditions

Service life time

Transient conditions

Core

Fuel clad: A 15/15-25 Ti, F/M 9-13-18Cr ODS S. Assembly : F/M 9-12 Cr

thin thick

370-550°C Hot peak : 650°C 8-12 m/s [O] < 5 ppm

4 y and more

T transient : 850°C(boiling) during a few hours max. number of event to be determined Chemistry transient : [O] = 15 ppm / 100 h

Fixed primary structures

A 316 LN

thick

400 - 450°C A few m/s [O] < 5 ppm

60 years

T transient : 850°C(boiling) during a few hours max. number of event to be determined Chemistry transient : [O] = 15 ppm / 100 h

Hot primary structures and components (pump, heat ex)

A 316LN F/M 9-12 Cr

thin thick

400 -550°C A few m/s [O] < 5 ppm

10y ? in case of Ni transfer via Na • Needs : – Not critical for use at T> 316L

Baqué_1981

EM12 - 640°C,

2 m/s, 1 ppm O - 8800 h • Restructuration in large grains • Weight loss 2011)

Lab. Scale experiment: Mechanisms & Modeling :

Specific testing device required

Well adapted for parametric testing over extended operating conditions including transients Saclay

Temperature - time - Re - [O]

Pilot scale experiment : validation Coupling effects

Cadarache


2009

T – t - Re - [O] close to normal operating conditions Reproduction or diffusion prohibited without CEA authorization

2012

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Corrosion testing device

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CORRONa (CORROsion Na)

Principle: thermal well with rotating cylinders and sodium mini-loop for chemistry control

- thermal well in gloves box for T control - inert crucible in contact with Na at high T to avoid any contamination - Na recirculation (mini loop) for chemistry control - rotating cylinders to control hydrodynamics

A A

?

- make sodium fire a negligible risk (double confinement, leaks detection, very low volume) - thermal control (cooling of the flange)

CEA Saclay - Bat 458 pièce 3


A

Moteur

?

Moteur

Recirculation

Recirculation

Cylindre éprouvette

Constraints :

A

LIBS

1ière barrière

Purificati Purification on

Purificati on Purification Cylindre éprouvette

2ième barrière

2 complementarily testing devices Na = 3.1 kg each Operating conditions: T = 500 - 625°C (designed for 750 °C) v = 500 - 10 000 tr/min (Re) [O] = 0,7 à 38 ppm Mini-loop : 1 l/h, 110-250°C with cold trap (= reactor circuits) Crucible : Molybdenum (MLR – 0.7% La2O3) Well : Nickel base alloy 625 Reproduction or diffusion prohibited without CEA authorization

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2 Laser

Laser LIBS (hublots) Moteur Brushless Moteur des cylindres tournants

Dé tection entré air (Zirox) Mini piège froid : 1 dl

Accouplement magnétique

Bride d’accostage puits Plancher BàG

Argon

Mini pompe Electro magnétique 1 l/h

Mini boucle de recirculation Joints

Boites à huile (thermocryostat)

Plaques de coupure thermiques Isolant céramique

Mécanisme tournant

Bac de rétention + Détection de fuite Na

Puits Creuset en Mo Coupons Na Cylindres Four Dé tection de fuite Na

Air

Accostage

Calorifuge

Creuset Na et internes



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3

Change of cylinder :



13


4

• Cooling fluid circuits Zone de refroidissement du palier

Traversée étanche sur Kf 40

Zone interne

Zone de refroidissement du couvercle Bride de jonction Bride d’accostage

Zone externe C2 ? C1 ?

R2 ?

R1 ?

BàG ?

Zone de refroidissement de la bride

C2 ?

Zone de refroidissement du pot

C1 ? R1 ?

Vanne réglante

R2 ?

bypasse

BàG ? XT750 XT150


2 thermocryostats


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5

• Sodium mini loop for chemistry control Vannes de la purge Préchauffages

Lignes de siphonage

h’ = 100 h = 100

Lignes de Gaz Piège froid Raccords swagelok ou SPG S

PEM

Bac de rétention +Détection de fuite Na par collier

CT

EM P

PEM

• Depressurization line (sodium/oil reaction) Disques de rupture Filtre à vapeur

Filtre à vapeur

Vue de haut

Clapet anti retour



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Prospect and others issues • CORRONA : 1 st test on well ? planned for October 2009 (625°C – 1000h - Re=0 - low [O]) • Materials program (priorities) : – CEA ODS steels (3 nuances) : never tested in sodium, mechanism, modeling – Fe-9Cr : little tested in Na, mechanism, modeling – Austenitic : model strengthening • Collaborations /other development support / support from – GD-MS measurement (M. Tabarant) for sodium sampling analysis - Saclay DPC /LRSI – LIBS (D. L’hermite, JB. Sirven) for on line chemistry monitoring - Saclay DPC /LRSI – Oxygen electrochemical measurement (V. Ghetta, C. Steil, J. Fouletier) - LEPMI/LPSC Grenoble – Electrochemical similitude, CFD modeling, EMP (A. Alemany SIMAP ) (V. Botton, C. Dumont) INSA Lyon – Mechanical properties with liquid metal interaction by Small punch test - Université de Lille (I. Serre, J-B. Vogt) – Mechanical properties with liquid metal interaction – ECP (T. Auger) • Others issues : – Hot concentrated acid corrosion for waste processing – Fissions products corrosion (internal fuel clad corrosion) – Water oxidation at high temperature for the steam generator component – NaOH corrosion (aqueous, concentrated, hot) (stress corrosion cracking) – Corrosion by other medias (Pb-Bi, scCO2) – Hydrogen et materials (embrittlement, tritium) – Water corrosion during storage before processing – Other kind of corrosion



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