[Back to Index
SINBAD ABSTRACT NEA-1517/54
1. Name of Experiment
Measurements of the JASPER program Radial Shield Attenuation Experiment (1986)
2. Purpose and Phenomena Tested
The radial shield attenuation experiment was designed to investigate neutron transmission
through benchmark and representative mockups of radial shield designs for advanced
3. Description of the Source and Experimental Configuration
The neutron source was the Tower Shielding Reactor II (TSR-II) located at the Tower
Shielding Facility at Oak Ridge National Laboratory. The emergent source spectrum was
modified to be similar to that predicted for the LMR (liquid metal reactor) design
using one of two different modifiers. One modifier approximated the energy distribution
for a near core shield while the other was designed to resemble the flux near the
intermediate heat exchanger (IHX).
The components used in the experimental mockups were slabs of stainless steel, graphite,
boron carbide, boral, and sodium. All slabs were 1.5m on a side with varying thicknesses.
The near-core spectrum modifier of iron, aluminum, boral and a "radial blanket" of natural
UO2 was placed in the beam. For the IHX modifier, the "radial blanket" was replaced with
183cm of sodium.
4. Measurement System and Uncertainties
Three different types of detection systems were used for this experiment. A set
of Bonner balls filled with BF3 gas was used to measure neutron flux. To cover
a range of neutron energies, the counter is used bare, covered with cadmium, or
enclosed in various thicknesses of polyethylene shells surrounded by cadmium.
An NE-213 liquid scintillator measured the spectrum from 800 keV to 50 MeV.
Spherical proton-recoil counters , filled with hydrogen to pressures of 1, 3,
and 10 atmospheres, covered the neutron energy range from about 50 keV to 1 MeV.
A study of sodium activation was made using sodium carbonate filled polystyrene
capsules measured utilizing a well-shielded Ge(Li) detector.
The uncertainty in the reactor power determination was assumed to be +/- 5%. The
NE-213 and hydrogen counter measurements were expressed in terms of lower and
upper limits that represented a 68% confidence interval. Both of the spectra for
these counters has an error of about +/- 5%. The errors assigned to the Bonner
ball measurements should lie within about +/- 10%.
5. Description of Results and Analysis
Six different measurements of the neutron spectra were taken: (1) near core shield,
(2) benchmark experiment, (3) tank type radial shield, (4) IHX shield, (5) graphite
benchmark, and (6) near core shield.
Data from the Bonner ball measurements was predicted analytically by folding a
calculated neutron spectrum with the Bonner ball response functions. The NE-213
pulse-height data was unfolded suing the FERD code to yield absolute neutron
energy spectra. Pulse-height data from the spherical proton-recoil counters was
unfolded using the SPEC-4 code.
The measurements for each detector were referenced to the reactor power (watts)
using the data from two fission chambers positioned along the reactor centerline
as a basis.
6. Special Features
This report has recently been released by the U.S. Department of Energy.
Experiment and Analysis:
F.J. Muckenthaler*, B.D. Rooney*, J.D. Drischler*, N. Ohtani**,
J.L. Hull*, L.B. Holland*
* Oak Ridge National Laboratory
** Japan Power Reactor and Nuclear Fuel Development Corporation
Compiler of data for SINBAD:
William Marshall, RSICC, Oak Ridge National Laboratory, P.O. Box 2008, Oak
Ridge, TN 37831-6362
Reviewer of compiled data:
Hamilton Hunter, RSICC, Oak Ridge National Laboratory, P.O. Box 2008, Oak
Ridge, TN 37831-6362, fax 423-574-6182, e-mail firstname.lastname@example.org
 R.E. Maerker et al., "Calibration of the Bonner Ball Neutron Detectors Used at the Tower
Shielding Facility," ORNL/TM-3465 (June 1971).
 C.E. Burgart and M.B. Emmett, "Monte Carlo Calculations of the Response
Functions of Bonner Ball Neutron Detectors," ORNL/TM-3739 (April 1972).
 B.W. Rust, D.T. Ingersoll, and W.R. Burrus, "A Users Manual for the FERDO and FERD
Unfolding Codes," ORNL/TM-8720 (September 1983).
 J.O. Johnson and D.T. Ingersoll, "Users Guide for the Revised SPEC-4 Neutron
Spectrum Unfolding Code," ORNL/TM-7384 (August 1980).
 W.W. Engle, Jr., D.T. Ingersoll, C.O. Slater, F.J. Muchenthaler, "Specifications
for the JASPER Program Attenuation Experiment," ORNL/LMR/AC-86/5 (October 1986).
10. Data amd Format:
(1)-(11) Composition and analysis tables of different matierials
(12)-(13) Neutron fluxes
(14)-(17) Bonner ball measurements
(18)-(19) Neutron fluxes
(20) Bonner ball measurements
(21)-(22) Neutron fluxes
(23)-(27) Bonner ball measurements
(28)-(29) Neutron fluxes
(30)-(31) Bonner ball measurements
(32)-(33) Neutron fluxes
(1) Spectrum modifier 1
(2) Radial blanket
(3) Spectrum modifier 2
(4) Stainless stell slabs for boron carbide
(5)-(24) Schematics of various experimental configurations
Document is HTML v.3.02 Format
SINBAD Abstract Generation Date: 6/99
SINBAD Abstract Last Update: 10/99