Arbeter, Frederik

Klimenko, Dmitry

Pasler, Volker

Schlindwein, Georg

von der Weth, Axel

Zinn, Kevin

English

Weth, Axel von der

KITopen

KIT – The Research University in the Helmholtz AssociationInstitute for Neutron Physics and ReactorTechnologyContact: <dmitry.klimenko@kit.edu>Definition of the Q-PETE Experiment for Investigati on of Hydrogen Isotopes Permeation through the Metal Stru ctures of a DEMO HCPB BreederDmitry Klimenko, Frederik Arbeiter, Volker Pasler, Georg Schlindwein, Axel von der Weth, Kevin ZinnExperimental setup and procedureThe Q-PETE/D2 experiment al setup in composed of1. A temperature controlled permeator setup enclosed in a vacuum vessel:a. The “retentate chamber” (formed by a stainless steel flange) is flooded and continously supplied with hydrogen containing feed gas (Argon + Deuterium),b. The “membrane” (1.2 mm Eurofer disk), through which the hydrogen permeates (time dependent flux   ),c. the “permeate chamber ” receives the permeated hydrogen from the membrane.2. A pure argon sweep flow collects the permeated hydrogen from the permeate chamber and transports it to a quadrupole mass spectrometer for time resolved quantitative detection.3. The setup is completed with a vacuum system , controlled purge gas supply and a temperature control system (200-600°C).Objectives and rationale of the Q-PETE experimentIn the HCPB, bred tritium is purged by a flow to the tritium extraction system. Tritium permeates into/through structures (cooling plates, pipes).The Q-PETE (Hydrogen Permeation and Transport Experimen t) was designed  as a “purged permeation setup” with morphology, materials, temperatures and hydrogen partial pressures  relevant for the HCPB :1. To produce relevant benchmark data for codes to predict the tritium losses in purged scenarios (application for safety and tritium budget).2. To directly derive material properties (Diffusivity, Sieverts constant).Characterization of mass spectroscopy methodLow noise and low background level of the mass spectrometer are key properties for successful experiments , because this allows sufficiently high purge gas flow rates to minimize residence time induced signal distortions.• The noise leve l was characterized dependent on the deuterium concentration, spectrometer dwell time and secondary electron multiplier (SEM)  voltage (selected value 1400 V). We envisage signal levels of 0.5 – 20 ppm and sampling times 0.1 – 2 s.• The background level at m/z=4 (D2, He) was systematically optimized:1. A needle valve was installed at the spectrometer outlet to keep the system pressure near 0.4 bar (g) over atmospheric p ressure ( to antagonize possible (helium) leaks in the valves of the inlet system).2. The unused part of the spectrometer inlet system are continuously evacuated by a membrane pump or turbomolecular pump to avoid any leakage into the measurement. The background is well suppressed and significantly lower than the corresponding limit of detection LOD 43 ppm of the GAM300. (See diagrams)10 100 100001020304050vol. flow, sccmLimit of Detection Signal Background at m/Z=4,  ppb0,000,050,100,150,200,250,300 100 200 300 400 500Inlet Y8, p4=1,6 bar , MP at Y19Inlet Y8, p4=1,6 bar , TP at Y19Inlet Y8, p4=1,3 bar , MP at Y19Inlet Y18, p4=1,6 bar, Heloka LP oultet is closedInlet Y18, p4=1,5 barOffset at m/Z=4 argon flow, in ppmInlet Y18, p4=1barvol.flow, sccmLOQ0 2 4 6 8 10050100150200250300350400Molar fraction of D2, ppmStandard deviation, ppb ∆tQMS=100ms ∆tQMS=200ms ∆tQMS=500ms ∆tQMS=1sSummary and ConclusionsQ-PETE/D2 was designed and optimized for HCPB-relevant D2 permeation through metal membranes at 200 - 600 °C for code validation.Time resolved measurements will be performed with mass spectroscopy.  The  method was optimized to suppress the background to  ~ 5 – 20  ppb (below limit of quantification!) . The limit of detection is 43 ppb and limit of quantification 141 ppb are well suited for measuring the expected signals  with levels of 0.5 - 20 ppm (D2). The Q-PETE experiment is assessed to be fit for its purpose and is currently under construction.Gas Inlet systemY17Q-Gas:Ar + DeuteriumxFGY11V15Purge gas: ArDelta 300-10 #1DAQ-PCSignalsPowerPipelineY7Y8VacuumpumpGAM300 xQMS(t)FFlow meter (JSG ,VSG, mSG)Dp2Dp1TTMTTHPIDYaYbYeV OutletYcY18FFlow meter (JFG ,VFG, mFG). . .. . .Dp4Q-PETE setupoverviewHCPBbreeding zoneQ-PETEpermeatordetailsQ-PETEprocessdiagramsystematicbackgroundoptimizationstepsfinally reached backgroundspectrometernoiseQ-PETEsetupduringassemblyat KIT-INRSee further posters at ISFNT-13:F. Arbeiter et al.   „Q-PETE simulation“,A. v.d Weth et al. „Q-PETE analysis“.[Hernandez 2016]retentate side concentrationpermeate side concentration~  Example signals :10 ppm D2 injected into retentatechamber at t = 20 s

Definition of the Q-PETE experiment for investigation of hydrogen isotopes permeation througn the metal structure of a DEMO HCPB breeder zone

https://publikationen.bibliothek.kit.edu/1000078177/6076650

Definition of the Q-PETE experiment for investigation of hydrogen isotopes permeation througn the metal structure of a DEMO HCPB breeder zone

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