SINBAD ABSTRACT NEA-1517/44
NESDIP-2 Benchmark Experiment (ASPIS)
1. Name of Experiment: ------------------ NESDIP-2 Benchmark Experiment (ASPIS) 2. Purpose and Phenomena Tested: ---------------------------- Neutron transport in a shield simulating the radial shield of a PWR, including the cavity region and the backing shield. 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 simulates the radial shield of a PWR and consists of 12.1 cm of water, a 6.3 cm stainless steel plate simulating the thermal shield, 13.2 cm of water, five mild steel plates giving a thickness of 22.8 cm to simulate the pressure vessel, a 29.4 cm cavity region and a backing shield of aluminium, water and mild steel. 4. Measurement System and Uncertainties: ------------------------------------ The detectors used were: Typical Counting Systematic Detector Diameter Thickness Mass System Absolute (mm) (mm) (g) Calibration (uncertainty) ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 5. Description of Results and Analysis: ----------------------------------- Measurements of the reaction rates S32(n,p)P32, In115(n,n')In115m and Rh103(n,n')Rh103m were made in activation foils between the mild steel plates (reactor pressure vessel region) and in the cavity whilst Rh103(n,n')Rh103m measurements were also made in the water regions. In addition, during all irradiations of activation detectors within the shields, three sulphur pellets were placed in locations at the centre of the front face of the fission plate to monitor its run-to-run power via the S32(n,p)P32 reaction. The results were corrected for the background responses due to the NESTOR core. Using the hydrogen filled proportional counters of the TNS system the correction was found to be around 2(+/-1)% in the RPV and cavity and 1(+/-1)% in the water cell. Calculations were carried out with the Monte Carlo codes McBEND Version 7B [1], [5]. 6. Special Features: ---------------- None 7. Author/Organizer ---------------- Experiment and analysis: A. Avery, 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: A. Avery, Reactor Physics, Shielding and Criticality Department, AEA Technology WINFRITH, Dorchester Dorset DT2 8DH UK 8. Availability: ------------ Unrestricted 9. References: ---------- [1] A. Avery, AEA-RS-5629, private communication [2] 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). [3] I. J. Curl, CRISP - A Computer Code to Define Fission Plate Source Profiles, RPD/IJC/934. [4] P. C. Miller, A Review of LWR Pressure Vessel Dosimetry and Associated Shielding Studies, Proceedings, 7th International Conference on Radiation Shielding, Sept. 12-16, 1988, Bournemouth, UK, Vol.1, p.37. [5] 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: --------------- Filename Size[bytes] Content ---------------- ----------- ------------- 1 nes2-abs.htm 8.007 This information file 2 nes2-exp.htm 23.538 Description of the experiment 3 NESD2-1V.TIF 78.510 Figure 1: Cross-section of the shield (high quality) 4 NESD2-2V.TIF 21.372 Figure 2: Measurement locations (high quality) 5 NESD2-3V.TIF 116.100 Figure 3: Schematic diagram of fission plate (high quality) 6 NESD2-4V.TIF 13.786 Figure 4: Fuel element (high quality) 7 NESD2-5V.TIF 80.340 Figure 5: Disposition of fuel in fission plate (high quality) 8 NESD2-6S.TIF 648.635 Figure 6: Positioning of the fission plate (high quality) 9 NESD2-1V.gif 26.444 Figure 1: Cross-section of the shield (preview) 10 NESD2-2V.gif 14.414 Figure 2: Measurement locations (preview) 11 NESD2-3V.gif 23.306 Figure 3: Schematic diagram of fission plate (preview) 12 NESD2-4V.gif 6.995 Figure 4: Fuel element (preview) 13 NESD2-5V.gif 23.589 Figure 5: Disposition of fuel in fission plate (preview) 14 NESD2-6S.gif 21.107 Figure 6: Positioning of the fission plate (preview) 15 NESDIP2.pdf 886.561 Reference 16 aspis_0.pdf 608.178 Reference 17 jef-476.pdf 578.980 Reference on of Experiment Tables: One table (1) of axial dimensions and (2) of material specifications, one table (3) describing the source distribution, and 3 tables (4-6) of the measured reaction rates. Figures describing the geometry of the experiment are included in TIFF4 image format and GIF (preview).