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SINBAD ABSTRACT NEA-1517/95

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.

    Three-dimensional fixed source transport calculations in Cartesian (X,Y,Z)
    geometry were performed [6] using the TORT-3.2 discrete ordinates transport
    code. The ENEA-Bologna BUGJEFF311.BOLIB (JEFF-3.1.1 data) and BUGENDF70.BOLIB
    (ENDF/B-VII.0 data) broad-group coupled neutron/photon (47 n + 20 g) working
    cross section libraries, together with the similar ORNL BUGLE-B7 (ENDF/B-VII.0)
    and BUGLE-96 (ENDF/B-VI.3) libraries, were used. A TORT input example, is 
    included (court. of M. Pescarini and R. Orsi, ENEA Italy).

    The transport calculations performed using the MCNP-5 code are described in
    [7,8,9]. 
    A two-dimensional model was also prepared for the DORT deterministic code and 
    used for the cross section sensitivity and uncertainty calculations (see [9]).
 
6. Quality Assessment:
    ----------------
    The Iron-88 experiment (NEA-1517/35) is ranked as a BENCHMARK QUALITY
    experiment. Nevertheless, additional experimental information would be
    advisable on:
    - detectors arrangement (e.g. stacking)
    - gaps between the slabs
    - absolute calibration of the neutron source (dilution factor)
    - effect of the cave walls

 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/Nuclear Energy Agency (NEA), 2 rue André Pascal, 75775 Paris Cedex 16, France

    Reviewer of compiled data:
    Alan F. Avery
    Reactor Physics, Shielding and Criticality Department, AEA Technology
    WINFRITH, Dorchester
    Dorset DT2 8DH
    UK

    Quality assessment:
    A. Milocco, 
    Universita' di Milano-Bicocca, piazza della Scienza 3, Milano, Italy

 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.
    [5] M. PESCARINI and R. ORSI, Validation of the BUGJEFF311.BOLIB, BUGENDF70.BOLIB,
        BUGLE-B7 and BUGLE-96 Cross Section Libraries on the Iron-88 Neutron Shielding
        Benchmark Experiment, ADPFISS-LP1-106, ENEA-Bologna Technical Report (2018).
    [6] M. PESCARINI and R. ORSI,The Iron-88 (Fe) Neutron Shielding Benchmark Experiment
        - Deterministic Analysis in Cartesian (X,Y,Z) Geometry Using the TORT-3.2 3D
        Transport Code and the BUGJEFF311.BOLIB, BUGENDF70.BOLIB, BUGLE-B7 and BUGLE-96
        Cross Section Libraries, SICNUC-P9H6-004, ENEA-Bologna Technical Report (2019)
    [7] A. Milocco, Quality Assessment of SINBAD Evaluated Experiments ASPIS Iron
        (NEA-1517/34), ASPIS Iron-88 (NEA-1517/35), ASPIS Graphite (NEA-1517/36),
        ASPIS Water (NEA-1517/37), ASPIS N/G Water/Steel (NEA-1517/49), ASPIS PCA
        Replica (NEA-1517/75), Dec. 2015.
    [8] A. Milocco, B. Zefran, I. Kodeli. Validation of nuclear data based on the ASPIS
        experimeents from the SINBAD database. V: Proc. RPSD-2018, 20th Topical meeting
        of the radiation protection and shielding division, 26-31 August 2018, Santa Fe.,
        American Nuclear Society. 2018.
    [9] I. Kodeli, Transport and S/U analysis of the ASPIS-IRON88 Benchmark using
        recent and older iron cross-section evaluations. Proc. PHYSOR 2018, Reactor physics
        paving the way towards more efficient systems, 22 - 26 April 2018, Cancun. ANS. 2018.


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 
 18 IRON88-ENEA_BOLOGNA.tar.gz 34.353.704 Input data for TORT-3.2 
 19 IRON88-ENEA_BOLOGNA_file_list.txt 2.195.113  Contents of IRON88-ENEA_BOLOGNA.tar.gz
 20 SICNUC-P9H6-004.pdf 2.195.113 Reference 6
 21 QualityAssess.pdf 6,851,768  Document on quality assessment of ASPIS experiments
 22 rpsd18.pdf                   Reference 8
 23 PHYSOR2018-fe88m.pdf         Reference 9

 
    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.

SINBAD Benchmark Generation Date: 1997
SINBAD Benchmark Last Update: 4/2019