SINBAD ABSTRACT NEA-1553/69
SBE 10.002
IAEA Benchmark
1. Name of Experiment: FNG Neutronics Bulk SS Shield Experiment (1995) 2. Purpose and Phenomena Tested: The neutronics experiments were performed to validate the International Thermonuclear Experimental Reactor (ITER) inboard shielding design. 3. Description of the Source and Experimental Configurations: Using a 14-MeV-fusion-neutron source (deuterium atoms accelerated onto a tritium target) at the ENEA Frascati Neutron Generator Facility was used to perform measurements of neutron penetration of a 94-cm-thick mockup of the first-wall, blanket, vacuum vessel, and toroidal field coils. The block was made of copper, stainless steel/Perspex (polyethelyne-type material, C5O2H8) sandwich, followed by a smaller block made of alternating plates of copper and stainless steel simulating the magnet. 4. Measurement Systems and Uncertainties: Activation foils were placed along the center line of the experimental block in line with the source axis. Foils were placed at various depths along the axis, irradiated with the neutron source, and its activity recorded from calibrated HPGe detectors. Errors from counting statistics, uncertainty of detector calibrations, and the uncertainty of the source intensity are included with the reaction rate results. Other errors are negligible. A set of TLD-300 detectors were used for measuring the nuclear heating as a function of depth inside the assembly. These were calibrated by a 60Co source. The neutron source intensity was measured by the associated particle method, using a Silicon Surface Barrier Detector (SSD). The accuracy of the measurement was +/- 2%. 5. Description of Results and Analysis: The activation foils were place at 3.43, 10.32, 17.15, 23.95, 30.80, 41.85, 46.85, 53.80, 60.55, 67.40, 74.40, 81.10, 87.75, and 92.15 cm from the front surface of the experimental block. Results are given with the total, systematic, and random error (in %). MCNP.4A was used to compute reaction rates for the foils. The absorbed dose measurements from the TLD-300 were taken at 3.36, 10.23, 17.09, 23.95, 30.81, 41.88, 46.88, 53.89, 60.72, 67.58, 74.57, 81.20, 88.01, 95.36, 97.36, 99.76, 101.96 cm from the front surface of the experimental block. Note that the measurements included the rear TF coil. The measurements include systematic, random and total error (%), with accompanying MCNP calculations. The absorbed dose in a material, Q, is given by the following equations: Q = Qn+Qp (QTLD) = CpQp+ CeCnQn Q = QTLD + Qp[(1-CeCn)Qn/Qp+(1-Cp)] , where QTLD is the response in the TLD, Qp and Qnis the gamma and neutron absorbed dose in the material, Cp is the ratio of photon dose in the TLD to the photon dose in the material, Cn is the ratio of neutron dose in the TLD to the neutron dose in the material. Finally, Ce is the neutron sensitivity of the TLD-300 taken from the published literature [6]. The cell heating deposition tally (F6 N,P in MCNP) was used to calculate the neutron and gamma heating in stainless steel or copper during n,p coupled transport calculations. The kerma factors for the photons and neutrons were taken from FENDL.1 and EFF-3 libraries. 6. Special Features: None 7. Author/Organizer: Experiment and analysis: P. Batistoni, M. Angelone, M. Pillon, L. Petrizzi, Associazione Euratom - ENEA sulla Fusione, C. R. Frascati - I- C. P. 65, 00044 Frascati, Italy Compiler of data for SINBAD: Hamilton Hunter, Radiation Shielding Information Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6362, fax 423-574-6182, e-mail h3o@ornl.gov. Reviewer of compiled data: P. Batistoni, ENEA Fusion Division Via E. Fermi 27, I-00044 Frascati (Roma), ITALY 8. Availability: Unrestricted 9. References: [1] M. Martone, M. Angelone, M. Pillon, "The 14-MeV Frascati Neutron Generator (FNG)", ENEA Report RT/ERG/FUS/93/65 [2] M. Angelone, M. Pillon, P. Batistoni, M. Martini, M. Martone, V. Rado, " Absolute experimental and numerical calibration of the 14 MeV neutron source at the Frascati Neutron Generator, Rev. Sci. Instrum. 67(6)(1996)2189 [3] P. Batistoni, M. Angelone, W. Daenner, U. Fischer, L. Petrizzi, M. Pillon, A. santamarina, K. Seidel, "Neutronics Shield Experiment for ITER at the Frascati Neutron Generator FNG", 17th Symposium on Fusion Technology, Lisboa, Portugal, September 16-20, 1996. [4] J. H. Baard, W. L. Zijp, H. Nolthenius, "Nuclear Data Guide for Reactor Neutron Metrology", Kluwer Academic Publishers for the Commission of the European Community, (1989). [5] M. Angelone, C. Arpesella, M. Martone, M. Pillon, " Activation measurements for the E.C. bulck shield benchmark experiment, Proc. of the 4-th Int. Conf. on Application of Nuclear Techniques, Crete (Greece) June 1994, SPIE Publ. vol. 2339 pp. 220-224 [6] M. Angelone, P. Batistoni. A. Esposito, M. Pillon, V. Rado, " Gamma and neutron dosimetry using CaF2:Tm thermoluminescent dosimeters for fusion reactor shielding experiments ", Nucl. Sci. Eng. 126, p 176 June (1997). [7] L. Petrizzi, V. Rado, M. Angelone, P. Batistoni, M. Martone, M. Pillon, " Analysis of nuclear heating experiments for the ITER shielding blanket, Proc. of a Specialist Meeting on Measurement, Calculation and Evaluation of Photon Production Data, Bologna, Italy Nov. 9-11, 1994, Edited by: C. Coceva, A. Mengoni, A. Ventura, NEA/NSC/DOC(95)1 10. Data and Format: Tables: (1) Source neutron spectrum averaged over spherical cap of 60 degree aperture. (2) Source FORTRAN file used by MCNP.4 to calculate 14-MeV neutron source. (3) GEOM.DAT - Geometry input file used by MCNP. (4) DETEC.DAT - List of activation reactions, foil locations, and foil size (5) RREXP.DAT - Experimental data for reaction rate measurements. (6) RRCALC.DAT - Calculated reaction rates using FENDL-1 library and MCNP (7) NHEXP.DAT - Expermental dose measurements for nuclear heating. (8) NHCALC.DAT - Calculated nuclear heating using MCNP/FENDL-1/EFF-3. Figures Fig. 1 - The bulk shield mock-up configuration Fig. 2 - The bulk shield mock-up assembly in front of FNG target, without the Polyethylene shield. Fig. 3 - The bulk shield mock-up assembly in front of FNG target, with the Polyethylene shield. Fig. 4 - The mock-up in position on the movable tower at the centre of the FNG bunker, at 4 m from the floor, at a distance of 5.3 cm from the neutron source. Document is HTML v.3.02 Format with ASCII Tables and Figures in GIF format. Abstract Generation Date: 06/98 Abstract Last Update: 09/98