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IEA collaboration in fusion neutronics Contributions of TU Dresden. 1. Experimental validation of shut-down dose rates. ITER Task T-426. H. Freiesleben, D. Richter, K. Seidel, S. Unholzer
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IEA collaboration in fusion neutronics Contributions of TU Dresden 1. Experimental validation of shut-down dose rates ITER Task T-426 H. Freiesleben, D. Richter, K. Seidel, S. Unholzer Technische Universität Dresden, Institut für Kern- und Teilchenphysik, Mommsenstr. 13, D-01062 Dresden, Germany Y. Chen1, U. Fischer Association FZK-Euratom, Forschungszentrum Karlsruhe, Institut für Reaktorsicherheit, P.O. Box 3640, D-76021 Karlruhe, Germany 1 Institute of Plasma Physics of Chinese Academy of Sciences, Hefei, Anhui, 230031 P. R. China M. Angelone, P. Batistoni, M. Pillon Associazione Euratom-ENEA, Centro Ricerche Energie Frascati, Settore Fusione, Via E. Fermi 27, I-00044 Frascati (Roma), Italy Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contributions of TU Dresden Motivation Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contributions of TU Dresden Vertical and horizontal cut of the assembly Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contributions of TU Dresden Irradiation: 1.95·1015 14-MeV neutrons during 2 days at FNG Time profile of the neutron source strength as recorded during the irradiation (thin line) and as described in the calculations (thick line) for the complete campaign (left hand) and for the last three hours (right hand). Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Dose rate measurement Detector: tissue-equivalent scintillator(NE 105), 4.6 cm * 4.6 cm ø. Calibration: air-kerma reference value (W/e = 33.97 V) in standard photon fields (19.9 keV ... 6.7 MeV) at PTB. Measurement: quasi-continuously with integration intervals from 5 min to 3 h. Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Experimental and calculated dose rate at several decay times Calculation: Rigorous two-step formalism (U. Fischer), MCNP+FENDL/MC-2.0, FISPACT+FENDL/A-2.0 Uncertainties: total experimental 3.9%; statistical uncertainty of about 1% for the calculated values Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Flux spectra of decay -rays Detector: liquid scintillator (NE 213), 3.8 cm * 3.8 cm ø Response: matrix of pulse-height distributions on absolute scale; unfolding with DIFBAS code (PTB) Structure of the spectra: flux in the cavity at t= 4380 s per one -ray started in SS316, calculated with the FISPACT energy groups (blue) and with E = 0.01 MeV Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Measured flux of the -rays with E > 0.4 MeV in comparison to the calculations Calculation: rigorous two-step method (U. Fischer), MCNP+FENDL/MC-2.0, FISPACT+FENDL/A-2.0. Uncertainties: total experimental, statistical only of the calculation Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Neutron flux spectrum Vertical cut of the assembly with NE 213 detector Fluence per one source neutron for E > 13.7 MeV, Experiment: (5.91 0.35)·10-5 Calculation: (5.96 0.32)·10-5 ———————————————— C/E = 1.01 0.07 Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden Results Gamma dose rates measured in a materials mock-up of the ITER shielding system with an uncertainty of about 4% over a period of three weeks after irradiation of the assembly with 14-MeV neutrons are consistent with the flux spectra of the decay -rays measured in that period. Rigorous two-step calculations with the MCNP code, using FENDL/MC-2.0 data, and with the FISPACT code, using FENDL/A-2.0 data, result in ratios of calculated-to-experimental values of C/E = 0.80 ... 1.08 for both dose rates and -flux, if material composition and irradiation scenario are described in detail. Underestimation of experimental values of 10 ... 20% is observed for the first week of decay, whereas overestimation up to 8% is obtained at the end of the campaign. ITER design calculations for similar assemblies and decay times with the codes and the data libraries, used in this task, have been validated within that uncertainties. Experimental data and calculated results may be used for investigating other (faster, simpler, approximate) calculation schemes. Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden 2. Experimental investigation of radioactivity induced in the fusion power plant structural material EUROFER and in other steels by D-T neutrons • K. Seidela, R. A. Forrestb, H. Freieslebena, V. D. Kovalchukc, • D. V. Markovskijd, D. V. Maximovichc, and S. Unholzera • a Technische Universität Dresden, Institut für Kern- und Teilchenphysik, 01062 Dresden, Germany • b EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon OX143DB, United Kingdom • c Coordination Centre ”Atomsafety”, 141300 Sergiev Posad, Moscow Region, Russia • d Russian Research Centre ”Kurchatov Institute”, 123182 Moscow, Russia Contribution to 10th International Conference on Fusion Reactor Materials, Baden-Baden Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD
IEA collaboration in fusion neutronics Contribution of TU Dresden 3. SiC benchmark experiment SiC assembly shipped from JAERI/FNS to Frascati TUD measurements in September 2001: Neutron flux spectra with NE213 spectrometer and hydrogen-filled proportional counter at 4 positions for E = 50 keV.... 15 MeV Gamma flux spectra with NE213 spectrometer at 4 positions for E = 20 keV.... 12 MeV Workshop, Baden-Baden, 18 October, 2001 K. Seidel, TUD