SINBAD ABSTRACT NEA-1517/35
Winfrith Iron 88 Benchmark (ASPIS)
1. Name of Experiment: ------------------ Winfrith Iron 88 Benchmark Experiment (ASPIS) 2. Purpose and Phenomena Tested: ---------------------------- Determination of the neutron transport for penetrations up to 67 cm in steel. 3. Description of the Source and Experimental Configuration: -------------------------------------------------------- The source is a fission plate constructed of 93% enriched uranium aluminium alloy driven by a thermal flux from the extended graphite reflector of the NESTOR reactor. The effective radius of the fission plate is 56 cm and the thickness 2 mm. The energy spectrum of the source is that of neutrons emitted from the fission of U-235. The absolute source strength is determined by fission product counting and the spatial distribution via detailed low energy flux mapping with activation detectors. The shield is made from 13 mild steel plates, each approximately 5.1 cm thick, with a gap of average thickness of 7.4 mm between them, to allow detector access within the shield. Each plate is 1.8 m x 1.9 m in cross-section. Behind this array is a deep backing shield manufactured from mild and stainless steel, respectively 20.32 cm and 22.41 cm thick. The outer boundaries of the experimental region are formed by the walls and floor (steel plates) of the ASPIS trolley and by the roof of the ASPIS cave. Concrete encases the whole assembly. 4. Measurement System and Uncertainties: ------------------------------------ The detectors used were: Typical Cadmium Counting Systematic Detector Diameter Thickness Mass Cover System Absolute (mm) (mm) (g) (inches) Calibration (uncertainty) ------------------------------------------------------------------------------ Au197(n,gamma) 12.7 0.05 0.12-0.13 50/1000 NaI 0.9% Rh103(n,n') 12.7 0.015 0.20 - NaI 3.0% In115(n,n') 38 1.63 12.79 - GeLi 1.9% detector S32(n,p) 38.1 2.41 5 - Plastic 5.0% Pressed Pellet Scintillator S32(n,p) 51 5.6 22 - Plastic 5.0% Cast Pellet Scintillator Al27(n,alpha) 50 3.1 16.72 - Ge detector 2.2% ------------------------------------------------------------------------------ 5. Description of Results and Analysis: ----------------------------------- Detector activation measurements were carried out along the fission plate axis at the following shield thicknesses: 0, 5.1, 10.22, 15.34, 20.44, 25.64, 30.79, 35.99, 41.19, 46.44, 51.62, 56.69, 61.81, 66.99 cm. Al27 reaction rates were measured only up to 25.64 cm. Lateral distributions were also measured at various positions in the shields, the foils being located at intervals of 25 cm up and down from the nuclear centre line. The results were corrected for the background responses due to the NESTOR core. Using the hydrogen filled proportional counters the correction was found to be around 2% throughout the shield for the four threshold detectors. For gold measurements the measurement was repeated with the fissile content of the fission plate removed in order to determine the background correction. Calculations were carried out with the Monte Carlo code McBEND version 7B. The corresponding input is included. 6. Special Features: ---------------- None 7. Author/Organizer ---------------- Experiment and analysis: S. Bell, I.J. Curl, G.A. Wright: AEA Technology WINFRITH, Dorchester Dorset DT2 8DH UK Compiler of data for Sinbad: I. Kodeli OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France Reviewer of compiled data: Alan F. Avery Reactor Physics, Shielding and Criticality Department, AEA Technology WINFRITH, Dorchester Dorset DT2 8DH UK 8. Availability: ------------ Unrestricted 9. References: ---------- [1] G.A. Wright, M. J. Grimstone, Benchmark Testing of JEF-2.2 Data for Shielding Applications: Analysis of the Winfrith Iron 88 Benchmark Experiment, Report No. AEA-RS-1231, EFF-Doc-229 and JEF-Doc-421 (1993). [2] I. J. Curl, CRISP - A Computer Code to Define Fission Plate Source Profiles, RPD/IJC/934. [3] M. J. Armishaw, J. Butler, M. D. Carter, I. J. Curl, A. K. McCracken, A Transportable Neutron Spectrometer (TNS) for Radiological Applications, AEEW-M2365 (1986). [4] G. A. Wright, A. Avery, M. J. Grimstone, H. F. Locke, S. Newbon, Benchmarking of the JEFF2.2 Data Library for Shielding Applications, Proceedings, 8th International Conference on Radiation Shielding, April 24-28, 1994, Arlington, Texas, U.S.A., vol.2, p.816. 10. Data and Format: --------------- DETAILED FILE DESCRIPTIONS -------------------------- Filename Size[bytes] Content ---------------- ----------- ------------- 1 as88-abs.htm 8.645 This information file 2 as88-exp.htm 25.009 Description of Experiment 3 MCBEND.INP 14.967 Input for McBEND MC Code (contributed by Dr. Chucas, Winfrith). 4 Fe88-1v.tif 62.008 Figure 1: Schematic Side Elevation of the ASPIS Shield (high quality) 5 Fe88-2v.tif 92.550 Figure 2: Measurement Locations (high quality) 6 Fe88-3v.tif 65.934 Figure 3: The Enriched U/Al Alloy Fission Plate (high quality) 7 Fe88-4v.tif 13.714 Figure 4: U/Al Alloy Fuel Element (high quality) 8 Fe88-5v.tif 76.474 Figure 5: Details of the Fuel Loading Pattern when Viewed Looking Towards the NESTOR Cave (high quality) 9 Fe88-6.tif 648.635 Figure 6: Fission Plate Positioning (high quality) 10 Fe88-1v.gif 22.383 Figure 1: Schematic Side Elevation of the ASPIS Shield (preview) 11 Fe88-2v.gif 30.363 Figure 2: Measurement Locations (preview) 12 Fe88-3v.gif 19.360 Figure 3: The Enriched U/Al Alloy Fission Plate (preview) 13 Fe88-4v.gif 6.976 Figure 4: U/Al Alloy Fuel Element (preview) 14 Fe88-5v.gif 24.229 Figure 5: Details of the Fuel Loading Pattern when Viewed Looking Towards the NESTOR Cave (preview) 15 Fe88-6.gif 20.935 Figure 6: Fission Plate Positioning (preview) 16 IRON_88.pdf 2.195.113 Reference 17 jef-476.pdf 578.980 Reference File AS88-exp.htm contains the following tables: One table of axial dimensions and of chemical composition of materials present in the configuration, one table describing the source distribution, and 5 tables of the measured reaction rates.
