[Back to index]

SBE 16.001

1. Name of Experiment
The Iron Shielding Benchmark Experiments at YAYOI - 1976

2. Purpose and Phenomena Tested:  

Transmitted neutron spectra through iron slabs, up to 20-cm-thick, were measured 
to assess the accuracy of both discrete ordinates and Monte Carlo codes as well as
to check neutron cross-section data sets.

3. Description of the Source and Experimental Configuration:  

The source of neutrons was generated by the YAYOI reactor at the University of
Tokyo.  It is a cylindrical core, 20 cm in diameter, surrounded by a depleted
uranium metal blanket and a lead reflector.  A Fast Column and a Thermal Column
on opposite sides of the reactor, collimated the neutron beam used in these 

4. Measurement System and Uncertainties:  
Three detectors were used to measure the transmitted spectrum behind the iron 
slabs.  A 2" x 2" NE-213 measured neutron spectra from 1.5 to 10 MeV.  The tabulated 
unfolding uncertainties at 1 sigma deviations were generated by FERDO.  The lower
energy neutrons were measured from 10 keV to 1 MeV using spherical proportional
detectors of H2 and CH4 gas.  These spectra were unfolded using the SPEC-4 code 
and have an estimated +/- 10% standard deviation in general, with +/- 25% in the 
deep spectral valleys.  

5. Description of Results and Analysis:  

Slabs of iron 9.6, 16, and 19.2 cm thickness were placed into the reactor beam and 
the transmitted spectrum measured.  Measurements were taken at 0 and 30 degrees
off centerline from the collimated neutron beam.  Results are plotted and
tabulated with their 1-sigma standard deviations.  Older analyses with ANISN and 
MORSE using ENDF/B-III and IV data files were performed.  Calculational results
were varied.

6. Special Features:

7. Author/Organizer  


    S. An, Y. Oka, M. Akiyama (University of Tokyo)
    T. Hyodo, T. Nishibe, K. Shin (University of Kyoto)
    T. Fuse, K. Takeuchi, A. Yamaji,T. Miura (Ship Research Institute)
    S. Miyasaka (Japan Atomic Energy Research Institute)
    S. Iwasaki (University of Tohoku)
    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 
    Reviewer of compiled data: 

    Kazuo Shin, Department of Nuclear Engineering, Kyoto University

8. Availability:   

9. References: 
    [1]   Results of the First Four Single-Material Experiments in Iron, NEACRP-U-73
          Ed. R. Nicks, EURATOM CCR, Ispra, May 1976.
    [2]   V. V. Verbinski, et al.: ANS-SD-2 (1964)
    [3]   P. W. Benjamin, et al.: AWRE-09/68 (1968)
    [4]   H. Tokumaru: private communication
    [5]   W. W. Engle, Jr.: K-1693 (1967)
    [6]   E. A. Straker, P. N. Stevens, D. C. Irving and V. R. Cain: ORNL-4585 (1970)
    [7]   H. Hirayama, T. Nakamura:  The memories of the Faculty of Engineering
          Kyoto University 34, part 2 (1972) Kyoto, Japan. 
    [8]   K. Shin, T. Nishibe, R. Murakami, H. Fujity, T. Hyodo, Y. Oka, and S.
          An "Fast Neutron Spectra Tansmitted through Iron and Sodium Slabs," 
          J. of Nuclear Science and Technology, 17 (1), (1980):pp 37-43
    [9]   Y. Oka et al.: Progress Report on Shielding Experiments at YAYOI
    [10]  Y. Oka et al.: Two-Dimensional Shielding Benchmarks for Sodium and Iron at YAYOI
    [11]  Y. Oka et al.: Two-Dimensional Shielding Benchmarks for Iron at YAYOI

10. Data and Format:  

 (1) Experiment #1 source and 16 cm Iron Results.
 (2) Experiment #2 source and 9.6, 19.2 cm Iron Results


 (1) Experimental #1 with 16 cm thick iron slab
 (2) Collimator for detector
 (3) Experiment #2 arrangement
 (4) Measured neutron spectra for 9.6 and 19.2 cm-thick iron slabs
 (5) Measured neutron spectra for 16 cm-thick iron slab

Document is HTML v.3.02 Format with ASCII Tables and Figures in GIF format.

SINBAD Benchmark Generation Date: 07/98

SINBAD Benchmark Last Update: 07/98