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SBE 1.003

1. Name of Experiment:

Measurements for the JASPER program Intermediate Heat Exchanger Experiment 

2. Purpose and Phenomena Tested:

The IHX experiment was designed to investigate and predict the sodium activation 
that will be generated in the secondary sodium contained with the IHX vessel.

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 used iron, 
aluminum, boral, and sodium, while the other used aluminum tanks filled with 

The configurations being tested included two general mockups.  The U.S.-
sponsored axial locations of the IHX vessel, and the Japanese model in which the 
IHX vessel was surrounded by partial or full complement shields.  The mockups 
were centered on the neutron beam emerging from the reactor shield.  
Measurements were made using a traversing mechanism that remotely positioned the 
detector while reactor power was maintained.

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 meausred 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

Nine different measurements of the neutron spectra were taken: (1) mockups below 
spent fuel region, (2) mockups in spend fuel region, (3) mockups for fission gas 
plenum region of spent fuel, (4) sodium with sodium side slabs IHX mockup, (5) 
boron carbide front shield with sodium side slabs IHX mockup, (6)boron carbide 
front shield with partial side shield IHX mockup, (7) boron carbide with boron 
carbide side slabs IHX mockup, (8)boron carbide front shield with aluminum 
window and boron carbide side shield IHX mockup, and (9) solid boron 
carbide/aluminum front shield with full boron carbide side shields IHX mockup.

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.

7. Author/Organizer

Experiment and Analysis:
        F.J. Muckenthaler*, R.R. Spencer*, H.T. Hunter*, J.L. Hull*, A. Shono**
        * 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 h3o@ornl.gov

8. Availability


9. References

[1] F.J. Muchenthaler, R.R. Spencer, H.T. Hunter, J.L. Hull, A. Shono, 
"Measurements for the JASPER Program Intermediate Heat Exchanger Experiment," 
Oak Ridge National Laboratory, ORNL/TM-12064 (July 1992).
[2] R.E. Mercker et al., "Calibration of the Bonner Ball Neutron Detectors Used 
at the Tower Shielding Facility," ORNL/TM-3465 (June 1971).
[3] C.E. Burgart and M.B> Emmett, "Monte Carlo Calculations of the Response 
Functions of Bonner Ball Detectors," ORNL/TM-3739 (April 1972).
[4] B.W. Rust, D.T. Ingersoll, and W.R. Burrus, "A User's Manual for the FERDO 
and FERD Unfolding Codes," ORNL/TM-8720 (September 1983).
[5] J.O. Johnson and D.T. Ingersoll, "User's Guide for the Revised SPEC-4 Neutron 
Spectrum Unfolding Code," ORNL/TM-7384 (August 1980).
[6] J.K. Dickens and S. Raman, "Fission-Producct Yield Data from the US/UK Joint 
Experiment in the Dounreay Prototype Fast Reactor," ORNL-6266 (1986).

10. Data and Format:

        (1)-(13) Composition and analysis tables of different setups
        (14)-(15) Bonner ball measurements
        (16) Sodium foil measurements
        (17)-(18) Neutron fluxes on centerline 25cm behind lead slabs
        (19)-(22) Bonner ball measurements
        (23) Sodium foil measurements
        (24) Bonner ball measurements

        (1) Schematic of spectrum modifier-2
        (2) Schematic of aluminum containers filled with sodium
        (3) Schematic of spectrum modifier-3 (sodium) plus lead
        (4) Isometric of the SPERT fuel rod
        (5) Schematic of IVFS Mockup
        (6)-(7) Schematic of stainless steel containers used for boron carbide
        (8) Schematic of aluminum slabs
        (9) Schematic of sodium foil locations
        (10) Schematic of spectrum modifier-2 for foil run
        (11)-(13) Schematics of spectrum modifier-2 for various runs
        (14)-(20) Schematics of spectrum modifier-3 for various runs

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SINBAD Abstract Generation Date: 6/99

SINBAD Abstract Last Update: 6/99