opportunities for research on material compatibility and tritium behavior at the star laboratory

Opportunities for researchon material compatibility

and tritium behavior at the STAR laboratory

Pattrick CalderoniFusion Safety Program

Idaho National Laboratory, USA

HAPL Program MeetingGA San Diego

8-9 August 2006

Fusion Safety Program

Slide 2

Objectives

Summarize recent and ongoing activities at INL that are relevant to the HAPL program

Introduce the INL Safety and Tritium Applied Research facilities and research capabilities in the areas of compatibility and tritium behavior for fusion chamber and blanket materials

Collect directives, comments, suggestions, impressions, desires, … on technical and programmatic aspects to consolidate the preliminary plan into an R&D proposal

Present a preliminary plan to integrate HAPL chamber and blanket R&D with the current and planned STAR activities


Slide 3

STAR Mission and Research• Provide laboratory infrastructure to study tritium science and technology

issues associated with the development of safe and environmentally friendly fusion energy

• Designated a National User Facility• Research thrust areas

– Plasma-material interactions of PFC materials with energetic tritium and deuterium ions

– Fusion safety: chemical reactivity, activation product mobilization and dust/debris characterization for PFC materials; tritium behavior in fusion systems (in-vessel source term)

– Molten salts and fusion liquids for tritium breeder and coolant applications– Fission reactor tritium production permeation issues; AGR fuel tritium

retention and release studies– Tritium plant and fuel cycle issues for MFE and IFE


Slide 4

15,000 Ci tritium limitSegregation of operationsGloveboxes and hoodsTritium cleanup systemOnce-through room ventilation

15,000 Ci tritium limitSegregation of operations/ventilationOnce-through room ventilationGloveboxes and hoodsTritium cleanup system (TCS)Tritium storage and assay system (SAS)

Tritium SAS

Glovebox TCS

Flibe-tritiumexperiment

Flibe-corrosionexperiment

D ion implantation experiment

Flibe preparationpurification & testing

Chemical reactivity experiment

Tritium Plasma Exp

Flibe Salt2Lif-BeF2

Glovebox exhaust manifold

TritiumStack monitor

STAR Floor-plan Layout


Slide 5

Key systems in STAR

Molten Salt Tritium Behavior Experiment Tritium

Storage and Assay System

Tritium Plasma Experiment and Enclosure

Tritium Cleanup SystemMolten Salt Preparation, Purification, and REDOX Experiments

Steam and air chemical reactivity test apparatus


Slide 6

• Molten Salt Tritium Permeation Experiment:– 100 to 300 Ci transferred as D2/T2 in vessel loaded with SAS– diagnostics to include QMS, gas chromatograph, on-line ion chamber,

and catalytic recovery– effluent will exhaust via facility stack

• TPE Tritium Experiments:– 700 to 900 Ci transferred as T2 in vessel loaded with SAS– local U-Bed capture in TPE; effluent routed to TCS for complete cleanup

• Useable tritium inventory currently 1300 Ci– 300 Ci in equimolar H2:D2:T2 calibration standard– 1000 Ci T2 available for experiments– shipments from SRS limited to 1000 Ci with

standard TYPE-A container

STAR is Ready for Operation of Tritium Experiments


Slide 7

Molten salts R&DRedox, the control of fluorine potential

• Experiments at Kyoto and Tokyo Un with fast neutrons (Moriyama, Oishi 97/89, Suzuki 98/00) showed that tritium is generated in Flibe as TF without the addition of H2

• TF reacts with structural materials generating high solubility fluorides

• Need to control fluorine potential to minimize corrosion

• Of the three options (purge H2/HF mixtures, add metal element, add ternary salt) the use of metallic Be is best for fusion applications when considering the complexity of ternary salts chemistry and T permeation issues

Fluoride Potential

-1200

-1000

-800

-600

-400

-200

0

450 550 650 750Temperature (°C)

-RTlnp

F2

(kJ/mole)

CeF3/CeF4

NiF2

H2/HF=10

FeF2

H2/HF =20/lowpressure H2CrF2

Si2F6

MnF2

AlF3

BeF2

LiF

D. Olander, letter to the editors of J Nuc Mat (02)

The redox condition of molten fluoride salts is quantitatively described by the fluorine potential.The fluorine potential, however applied, controls the equilibrium concentration of structural materials dissolved in flibe.


Slide 8

Hydrofluorination is first used to purify the salt from oxides and metal impurities:M + 2HF <--> MF2 + H2

BeO + 2HF = BeF2 + H2O

• On-line detection of HF in the gas with titrator and mass spectrometer allows dynamic time dependent analysis

• Controlled parameters: HF/H2 concentration, temperature, Be exposure time

Inject HF

into the Flibe

Measure HF in the gas phase as a signature of REDOX potential

Be rod

Molten salts R&D: redox experiments

When equilibrium is reached (pure salt) a metallic Be rod is inserted in the salt for a specified time

Available Be reacts with HF until initial conditions are restored


Slide 9

Flibe purification facilitiesHydro-fluorination approach

• Bubble H2/HF/He thru melt (530ºC)

Chemical Analysis of Flibe• On components• Pre and post purification• Techniques:

Metals: ICP-AES, ICP-MS, acid dissolution

C, N, O: LECO

O(ppm)

C(ppm)

N(ppm)

Fe(ppm)

Ni(ppm)

Cr(ppm)

BeF25700 <20 58 295 20 18

LiF 60 <20 78 100 30 4Flibe 560 10 32 260 15 16

Control instruments & He-HF gas cabinet

Pot/heater assemblyTitration cellGas manifoldsHF traps

ProcessedFlibe


Slide 10

Redox experiments: analysis and complexities

0

200

400

600

800

1000

1200

1400

0 10 20 30 40 50 60 70time (hr)

HF concentration (ppm)

REDOX-4REDOX-5REDOX-6REDOX-7REDOX-10

10 min

20 min30 min 60 min

Simple modelBe dissolves as Be0HF input (1000 ppm) > dissolution rateExposure time does not influence recovery (only HF concentration)

but

Solubility of Be0 from integration of titrator data higher than MSRE

Complex model

Be dissolves as Be0 and enters the salt by galvanic mechanism as ionic Be2+

(demonstrated by recent tests with insulated Be rod)Initial ionic migration > HF input and Be deposits on Ni crucibleExposure time does not influence recovery (only HF concentration and available deposition surface for ions)Currently measuring ionic migration by electrochemical analysis to decouple processes


Slide 11

Ferritic steel corrosion tests

TC

He+H2+HF

HeHe

He

He

He+H2+HF

FSCT #1 and #2 concluded

Analysis of results ongoing at INL and in Japan - stay tuned for Jupiter II final reports


Slide 12

Tritium permeation experiments

Ni10060.32.82215010Ni30956.3512.76.359.52NiNiss3162409.52lid ss316114160306.35φ6.35 φ6.35 φss31612.720446.352411010812

Experiments are designed to investigate tritium behavior in flibe / Ni systems with Redox control

Previous experiments in Japan under irradiation complicated by oxide layer formation

Chamber designed and constructed in Japan, tested with H2 to verify negligible convection effects

Gas supply system, glove-box, instruments and control already tested with previous D2 permeation experiment


Slide 13

Tritium permeation experiments

Ar D2

Flow meter

Flow meter

Flow meter

Gas chromatograph

+ ionization chamber

And QMS

HF trap

exhaust

High temperature salt

Flibe

Cap

Ni

T2

Vacuum pump

Pressure gauge

Be insertion

• Tritium provided in pressurized vessel containing D2/T2 mixture

• Glovebox setup to contain potential leaks, connected with tritium clean-up system

• GC column coupled with ionization chamber has been tested with tritium

• Develop DF/TF generator to compare with T2 permeation results

• Builds on success of TMAP modeling with D2 permeation experiment

• 1-D axial model with sink terms to simulate radial loss


Slide 14

Flibe and Sn-Li alloy mobilization studies for blanket safety analysis

Objectives: measure the vaporization and mobilization properties of molten Sn 25at%Li (in argon) and flibe (in argon, air and air+water vapor) from 600 to 1400K

Approach: use a mass spectrometer equipped with a Knudsen effusion source to measure the partial pressure of condensable vapors. Partial pressures are derived from spectral line intensities after calibration with Li metal. Mobilized deposits were analyzed by ICP-AES.


Slide 15

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Pb-Bi corrosion test for Fast Breeder Reactor


Slide 16



Corrosion mechanism in liquid metals


Slide 17



Corrosion mechanism in liquid metals


Slide 18



Pb-Bi corrosion test for Fast Breeder Reactor


Slide 19

Integration of HAPL chamber and blanket R&D with current and planned STAR activities

A gradual integration would be beneficial to:

• minimize budget for research activities and facilities

• allow maximum flexibility to accommodate design changes and leverage on other R&D programs with common objectives (ITER-TBM, Z-IFE, GNEP, etc)

• incorporate INL Fusion Safety Program expertise in the HAPL chamber and blanket design and analysis

• start a collaborative program that could lead to a full utilization of the STAR laboratory capabilities, including applied research on tritium behavior in blanket materials, tritium inventory assessment and blanket safety analysis


Slide 20

Task 1 FY 1 FY2 FY3

Static compatibility test: SiC / flibe

Design and construction

Operation

Analysis

Redox and corrosion tests: SiC / flibe


Operation

Analysis


Task 1 SiC / flibe material compatibility tests and Redox control assessment and optimization

Flibe batch preparation

Requires minimal modification of available STAR facilities for T < 700C

Utilizes available state-of-the-art analytical techniques, including electrochemical measurements, and extensive expertise of scientific and technical personnel

Allows comparison with static compatibility tests of Pb-17Li for TBM program ongoing at ORNL (B. Pint)


Slide 21


Task 2 SiC / Pb-17Li material compatibility tests and corrosion control assessment and optimization

Task 1 FY 1 FY2 FY3

Prepare and purify Pb-17Li


Operation

Analysis

Corrosion control tests: SiC / Pb-17Li


Operation

Analysis

Requires re-assembly and modification of Pb-Bi alloy experiment

Utilizes available state-of-the-art analytical techniques and expertise of scientific and technical personnel

Start could wait until completion of Task 1 to leverage on other R&D and continued analysis and design of HAPL chamber and blanket system (ie, choice of coolant)


Slide 22


Task 3 T permeation experiments in SiC / flibe systems and SiC / Pb-17Li systems

Task 1 FY 1 FY2 FY3

T perm test: SiC / flibe


Operation

Analysis

Requires modification of planned T permeation experiments in flibe / Ni systems for T < 700 C

Utilizes available state-of-the-art analytical techniques and expertise of scientific and technical personnel

Start would depend on Task 1 and 2 results, as well as continued HAPL blanket analysis and design (ie, coolant material choice)

If comparison of material properties is needed research activities for flibe and Pb-17Li could be carried out in parallel depending on research budget and personnel availability

Opportunities for researchon material compatibility

and tritium behavior at the STAR laboratory

Pattrick CalderoniFusion Safety Program

Idaho National Laboratory, USA

HAPL Program MeetingGA San Diego

8-9 August 2006

opportunities for research on material compatibility and tritium behavior at the star laboratory

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