SINBAD ABSTRACT NEA-1517/98
Winfrith Graphite Benchmark Experiment (ASPIS)
1. Name of Experiment:
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Winfrith Graphite Benchmark Experiment (ASPIS)
2. Purpose and Phenomena Tested:
----------------------------
Determination of the accuracy of methods used to calculate the neutron
component of nuclear heating. Threshold reaction rates were measured up
to 0.7 m in graphite.
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 energy spectrum of the source is
the one 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 graphite assembly had lateral dimensions 180 cm x 190 cm and total
length was 177.32 cm. It was built from graphite block of various sizes.
The concrete of the approximate thickness 76 cm encases the whole assembly.
The detectors were placed in the central block in the cylindrical plug,
inserted in 6.45 cm radius hole along the major axis of the block.
4. Measurement System and Uncertainties:
------------------------------------
The detectors used were:
Detector Diameter Thickness Mass Counting Systematic
(mm) (mm) (g) System Error (%)
------------------------------------------------------------------
Al-27(n,alpha) 50 3.1 16.72 Ge detector 4.0
S-32(n,p) 38.1 2.41 5 Plastic scint. 4.0
In-115(n,n') 38 1.63 12.79 GeLi detector 3.0
Rh-103(n,n') 12.7 0.015 0.20 NaI 3.0
------------------------------------------------------------------
The uncertainties (1 sigma) may be taken as uncorrelated, and derive
essentially from the absolute calibration of the counting system.
5. Description of Results and Analysis:
-----------------------------------
Detector activation measurements were carried out at several graphite
distances: 0, 5, 10, 15, 20, 30, 40, 50, 60, 70 cm. The positions
correspond approximately to the fission plate axis. Not all detectors
were placed in all positions.
The results were corrected for the background responses due to the NESTOR
core. They were measured for Al-27, S-32 and Rh-103. For In115 those for
Rh-103 were assumed.
Calculations were carried out with the Monte Carlo code McBEND and the
discrete ordinates code DOT 3.5.
The corresponding input to the 2-D discrete ordinates transport code
DOT-3.5 is provided.
More recently the MCNP5 models were prepared [6] in the scope of the
quality review process and are also incuded in this compilation.
6. Quality Assessment:
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The Graphite experiment is ranked as experiment of BENCHMARK QUALITY.
Nevertheless, obtaining additional experimental information would be
valuable on:
- detectors arrangement in the slots (dimensions are inconsistent)
7. Author/Organizer
----------------
Experiment and analysis:
M.D. Carter, P.C. Miller, A. Packwood:
AEA Technology
WINFRITH, Dorchester
Dorset DT2 8DH
UK
Compiler of data for Sinbad:
I. Kodeli
Institute Jozef Stefan, Ljubljana, Slovenia (ivan.kodeli at ijs.si)
& UKAEA/CCFE Culham, UK (ivan.kodeli at ukaea.uk)
Reviewer of compiled data:
Alan F. Avery
Reactor Physics, Shielding and Criticality Department , AEE Technology
WINFRITH, Dorchester
Dorset DT2 8DH
UK
Quality assessment:
A. Milocco,
Universita' di Milano-Bicocca, piazza della Scienza 3, Milano, Italy
8. Availability:
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Unrestricted
9. References:
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[1] M.D. Carter, P.C. Miller, A. Packwood,
The ASPIS Graphite Benchmark Experiment. Part 1 - Experimental Data
and Preliminary Results, NEACRP-A-630 (1984)
[2] N. Sasamoto, K. Sakurai, A. Tsubosaka, H. Narita, M. Takemura,
K. Hayashi, Analysis of the ASPIS Graphite Benchmark Experiment with
Discrete Ordinates and Monte Carlo Codes,
NEACRP Specialists' Meeting on Shielding Benchmarks, Paris (1986).
[3] Alan F. Avery, AEA-RS-5628, private communication.
[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] 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.
[6] 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.
10. Data and Format:
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Filename Size (bytes) Content
---------------- ----------- -------------
1 ASC-ABS.HTM 9.166 This information file.
2 ASC-EXP.HTM 20.668 Description of Experiment.
3 dot35.INP 4.684 2-D Model for Sn code DOT-3.5.
4 ASPC-1V.TIF 27.464 Figure 1: Cross-section of the ASPIS graphite benchmark experiment.
5 ASPC-2V.TIF 17.362 Figure 2: Detail of the fission plate.
6 ASPC-3V.TIF 17.696 Figure 3: Section through the ASPIS graphite benchmark model.
7 ASPC-4V.TIF 16.136 Figure 4: RZ geometry of the ASPIS graphite benchmark for the DOT 3.5 calculation.
8 ASPC-1V.gif 20.266 Figure 1: Cross-section of the ASPIS graphite benchmark experiment. (preview)
9 ASPC-2V.gif 12.183 Figure 2: Detail of the fission plate. (preview)
10 ASPC-3V.gif 14.797 Figure 3: Section through the ASPIS graphite benchmark model. (preview)
11 ASPC-4V.gif 11.482 Figure 4: RZ geometry of the ASPIS graphite benchmark for the DOT 3.5 calculation. (preview)
12 WIN_C_1.pdf 2.237.854 Reference
13 WIN_C_2.pdf 458.475 Reference
14 WIN_C_3.pdf 789.823 Reference
15 WIN_C_4.pdf 578.980 Reference
16 rpsd18.pdf 4.323.119 Reference
17 QualityAssess.pdf 6.851.768 Document on quality assessment of ASPIS experiments
18 rh36.i 61.619 MCNPX(5) input model with Rhodium detector
19 s36.i 60.791 MCNPX(5) input model with Sulphur detector
20 in36.i 38.801 MCNPX(5) input model with Indium detector
21 al36.i 38.782 MCNPX(5) input model with Aluminium detector
Figures describing the geometry of the experiment are included in TIFF and
GIF (preview) format.
Tables in Asc-exp.htm:
one table of axial dimensions and of chemical composition of materials
present in the configuration, 3 tables describing the source, and
4 tables of the measured reaction rates.
SINBAD Benchmark Generation Date: 1997
SINBAD Benchmark Last Update: 5/2017