SINBAD ABSTRACT NEA-1517/83
Baikal-1 Skyshine Benchmark Experiment
1. Name of Experiment:
------------------
Measurements of spatial energy distributions of neutrons and photons
scattered in the air near the ground-air interface (skyshine-experiment)
(1996-1998).
2. Purpose and Phenomena Tested:
----------------------------
Detailed studying of the spatial energy distributions of neutrons and
photons scattered in the air near the ground-air interface for
generation of a database (of experimental and analytical nature) to
verify the computer codes that are used for justification of the
radiation and ecological safety of population residing in direct
proximity to nuclear power plants.
3. Description of the Source and Experimental Configuration:
--------------------------------------------------------
The experimental studies were carried out at the research RA reactor
incorporated in the "Baikal-1" unique complex of research reactors near
Semipalatinsk, belonging to Kurchatov Institute of Atomic Energy in the
Kazakhstan National Nuclear Centre (IAE NNC RK), being constructed in
thinly populated steppe area. The altitude differences in the region of
measurements (0.0 - 1500 m from the source) never exceed ±5 m. The
distance from the nearest residential settlements was at least 60 km.
The vegetative cover is purely grass; its height doesn't exceed 20-30 cm
above the soil layer.
The core of the RA research reactor was the source of neutron and photon
radiation; the core was 700 mm high and 297 mm in diameter comprising 37
air-cooled fuel assemblies with highly enriched fuel made of uranium
carbide. A zirconium hydride cylinder 339 mm in diameter was used as a
moderator. There were 372 holes (3 mm in diameter) bored in it for
cooling. Lateral reactor side shielding consisted of the beryllium
reflector 102 mm thick, the 16 mm steel vessel and additional graphite
reflector 180 mm thick.
Biological shielding made of heavy serpentinite concrete, 1100-1400 mm
thick, was arranged around the core and reflectors; from outside the
shielding was surrounded with a steel bell-shaped structure, about 350
mm thick. In the upper direction the shielding consisted of a steel
plate (reactor cover) ~ 120 mm thick, and a concrete block (shielding
plug) – its thickness was about 850 mm immediately above the reactor.
This block was removed during the experiments to ensure release of
highly intensive fluxes of neutron and photon radiation to the air. The
measurements which were made close to the reactor on the outer surface
of biological shielding at the levels of ground surface and 1-2 m above
it showed that reactor radiation is completely released to the air
uprightly, and there was no reactor-caused radiation that directly
reached the detectors as line-of-sight beams. During the experiment the
spatial detection points were located at the height of 1.0 m above the
ground at a distance from 50 to 1500 m from the reactor axis.
Reactor power during measurements was 300 kW.
4. Measurement System and Uncertainties:
------------------------------------
Measurements of neutron energy spectra were conducted within the wide
range of energy (30 keV - 10 MeV) applying the following sets of
spectrometric instruments:
• 1H-spectrometer with a cylindrical counter (Ø32×150 mm), its
energy range is 30 - 400 keV; the measurement error is ±(20 - 30)%.
• 3He-spectrometer with a cylindrical counter (Ø32×150 mm),
its energy range is 0.05 - 2.5 MeV; the measurement error within the
range of energy higher 1 MeV is ±(15 - 20)%, and it doesn't exceed
±(10-15)% for the range of 0.1 - 1 MeV;
• scintillation spectrometer of fast neutrons with a stilbene
crystal (Ø40×40 mm) and the energy range of measurements is 0.8 - 10
MeV; the measurement error is ±(10 - 15)% for the range of 1-3 MeV, and
±(15 - 20)% - if the energy is higher that 3 MeV;
• multisphere spectrometer with a set of 6 spheres, their
diameters varying from 51 to 305 mm. The spectrometer features a high
sensitivity and ability to measure in the energy range of 1 eV - 10 MeV.
The photons energy spectra were measured by:
• scintillation gamma-spectrometer with a stilbene crystal
(Ø40×40 mm) in 0.1 - 10 MeV energy range; the measurement error within
the range of energy of 0.1 - 2.0 MeV is ±(15 - 20)%, and it increases up
to ±(30 - 40)% for the energy higher than 2.0 MeV.
The neutron fluxes were measured by:
• MKS-01R radiometer-dosimeter with the BDKN-03R detection unit
and two polyethylene spheres have 240 and 150 mm in diameter; the
measurement error doesn't exceed ±20%.
• scintillation fast neutron counter with pellet of ZnS(Ag) +
organic glass detector (Ø80×6 mm); the measurement error for fast
neutron flux is ±(15-20)%;
• scintillation thermal neutron counter with ZnS(Ag) + boron
detector (Ø40×200 mm); the measurement error is ±(20-30)%.
For the photon dose rates the following instruments were used:
• MKS-01R radiometer-dosimeter with the BDKG-02R detection unit
and tissue-equivalent scintillator (Ø25×25 mm) and DBG-01-N, DRG-01T
dosimeters; the measurement error doesn't exceed ±(20 - 30)%.
• a set of the IKS-A type thermoluminescent dosimeters based on
the aluminophosphate glass, the energy range is 0.5 - 1000 rad. The
measurement error within the photon energy range of 30 keV to 6.1 MeV
does not exceed ±20%.
Sets of threshold and resonance detectors were used to measure the
reaction rates and unfolding of neutron spectra near the core; the
energy range is 0.1 eV - 10 MeV, and total error of measurements does
not exceed ±30%.
5. Description of Results and Analysis:
-----------------------------------
Basic parameters of neutron and photon radiation released to the
atmosphere were measured during 1996-1997 in several series of
experimental studies at the RA reactor:
• Fast and thermal neutron fluxes, dose rates of neutron and
photon radiation at various altitudes from the reactor cover;
• Spatial differential energy distributions of neutrons at various
distances from the reactor axis (100, 200, 400, 500, 600, 800, 1000 m);
• Spatial distribution of neutron radiation dose rate at 50 from 1500 m;
• Energy distribution of photon radiation fluxes and photon dose
rates at various distances off the reactor.
In addition
• Influence of weather conditions and soil composition on
radiation field characteristics has been studied;
• It has been demonstrated that neutron radiation makes the major
input to the total dose rate in the vicinity of the reactor;
• It has been showed that for the case of long distances from the
reactor the photons emerging as a result of thermal neutrons radiation
capture in the soil, give a major contribution into photon dose rate in
comparison to the photons emerging as a result of inelastic scattering
of neutrons in the air.
6. Special Features:
----------------
1. The work was accomplished during the years of 1996-1998
within the project # 517 of the International Scientific and Technical
Centre under the contract with Japan Ministry of Foreign Affairs;
2. As the result of work the set of experimental and computed
data which provided detailed description of radiation situation both
around the reactor and the regularities in radiation fields formation
stipulated by scattering of reactor-caused radiation in the air, ground
reflection and emerging of photons due to neutrons radiation capture in
the soil under different weather conditions has been received;
3. At all stages of work analytical estimation of data using
the codes and methods of high accuracy (Monte-Carlo method, method of
discrete ordinates) was carried out.
7. Author/Organizer
----------------
Experiment:
Yu.V.Orlov, V.N.Avaev, G.A.Vasiljev, N.N.Soukharev, A.I.Yashnikov
(FSUE RDIPE, P.O. Box 788, Moscow, 101000, Russia)
Analysis:
M.E.Netecha, O.F.Dikareva, V.P.Zharkov, I.A.Kartashev
(FSUE RDIPE, P.O. Box 788, Moscow, 101000, Russia)
Compiler of data for SINBAD:
M.E.Netecha, O.F.Dikareva, V.P.Zharkov, I.A.Kartashev
(FSUE RDIPE, P.O. Box 788, Moscow, 101000, Russia)
Evaluators for ICSBEP:
O. F. Dikareva, I. A. Kartashev, M. E. Netecha, V. P. Zharkov
Research Development Institute of Power Engineering
Reviewer of SINBAD compiled data:
I. Kodeli
OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France
ICSBEP Internal Reviewer:
A. P. Vasiliev
ICSBEP Independent Reviewers
Dale Hankins, USA
Virginia Dean, USA
International Criticality Safety Benchmark Evaluation Project (ICSBEP)
8. Availability:
------------
Unrestricted
9. References:
----------
[1] I.I. Deryavko, V.S. Zhdanov, I.G. Perepelkin, Yu.S. Cherepnin,
Radiating stability of carbide materials at an irradiation in
the reactor with low neutron fluxes. VANT, ser. Physics of radiating
damages and radiating materiology. Kharkov, v. 1, ð.48, 1992
[2] Zh.R. Zhotabaev, D.I. Zelensky, Î.S. Pivovarov, V.P.
Smetannikov, Yu.S. Cherepnin. Possibilities of the experimental base
of Kazakhstan for tests of elements of space nuclear reactors. Bulletin
NNC RK, "Nuclear engineering and safety of the nuclear power station",
v.1, ð.7, 2000
[3] Sc.T. Tuhvatulin, I.L. Tazhibaeva, V.P. Smetannikov, V.P.
Pavshuk, N.N. Ponomarev-Stepnoj, I.I. Fedik, Yu.S. Cherepnin. Reactor
complexes of the National nuclear center of Republic Kazakhstan. Proc.
of the International conference "Experience of Designing of nuclear
reactors", Moscow, 2002
[4] MCNP - A General Monte-Carlo N-Particle Transport Code, Version 4B,
LA-12625-M (March 1997)
[5] S. Berg. Modification of SAND-2. BNWL-855, 1968
[6] I.A. Bochvar, T.I. Imadova et al. Method of IKS Dosimetry,
M., Atomizdat, 1977
[7] MKS-01R Radiometer-Dosimeter. Certificate Zh1P.289.201PS
[8] V.N. Avaev, G.A. Vasiliev et al. Experimental Studies of
Gamma and Neutron Radiation Fields. Edited by Yu.A. Egorov, M.,
Atomizdat, 1974
[9] R.L. Bramlett, R.I. Ewing, T.W. Bonner. A New Type of Neutron
Spectrometer. Nucl. Instr. and Meth., 1960, v. 9, n.1, p. 1
[10] R.H. Johnson, B.W. Wehring, J.J. Dorning. Nucl. Sci.Eng., v.73,
1980, p.93
[11] R.V. Hemming, Numerical Methods. Nauka, M., 1968
[12] L.Z. Rumshinsky. Mathematical Processing of Experimental Results,
M., Nauka, 1971
[13] R.D. Vasiliev et al. Method of Reaction Rate Calculation and
Its Errors. In collection: Metrology of Neutron Measurements at
Nuclear-Physical Facilities. M., Atominform, 1976
[14] A.A. Gui, J.K. Shultis, R.E. Fow. Response Functions for Neutron
Skyshine Analysis. Nucl. Sci. Eng., 1997, v. 125, No. 2, p.111-127
[15] W.A. Rhoades, R.L. Childs. The DORT Two-dimensional Discrete Ordinates
Transport Code. Nucl.Sci.Eng. 99, 1, 88-89 (May 1988)
[16] RSIC library DLC-23/CASK. 40-Group coupled neutron and gamma-ray
cross-section data, 1973
[17] Zharkov V.P., Dikareva O.F., Kartashev I.A., Kiselev A.N., Netecha M.E.,
Sakamoto H., Nomura Y., Naito Y., Analytical Study of Reactor Radiation
Scattering in the Atmosphere, Proc. of ANS conference "Technologies for
the New Century", Tennessee, Nashville, USA, April 1998
[18] Yu.V. Orlov, M.E. Netecha, V.N. Avaev, G.A. Vasiljev, Yu.L. Istomin,
D.I. Zelensky, Yu.S. Cherepnin, H. Sakamoto, Y. Nomura, Y. Naito,
Neutron and Gamma-Radiation Skyshine Experiment at Nuclear Reactor,
Proc. of ANS conference "Technologies for the New Century",
Tennessee, Nashville, USA, April 1998
[19] M.E. Netecha, O.F. Dikareva, V.P. Zharkov, I.A. Kartashev,
Compilation of the series of measurements of spatial energy distributions
of neutrons and photons scattered in the air near the ground-air
interface in standard SINBAD Database format, Final Report, Federal
Agency for Atomic Energy, Federal State Unitary Enterprise, Research
and Development Institute of Power Engineering, Moscow 2005.
[20] Final Report on ISTC Project No. 517-96:
Experimental study of reactor radiation scattering in the atmosphere
(for a period of 24 months from September 1, 1996 to August 31, 1998),
Mikhail E. Netecha, (Project Manager),
Research and Development Institute of Power Engineering,
September, 1998
[21] "BAIKAL-1 SKYSHINE EXPERIMENT" ICSBEP evaluated version September 2009
(NEA/NSC/DOC/(95)03/VIII Volume VIII)
10. Data and Format:
---------------
DETAILED FILE DESCRIPTIONS
--------------------------
Filename Size[bytes] Content
--------------- ----------- -------------
1 sks_a.htm 22.140 This information file
2 sks_e.htm 64.742 Description of Experiment
3 sks-f1.gif 61.675 Fig. 1: Schematic diagram of the RA reactor
4 sks_f2.gif 72.122 Fig. 2: Detailed diagram of the RA reactor core
1) Radial cross section of the fuel assembly;
2) Radial cross section of the some part of RA core
with the steel vessel and reflector;
3) RA core and its vicinity. Material zone numbers
are taken in the Tables 1-2.
5 sks_f3.gif 68.093 Fig. 3: Detailed model of the experiment
6 sks_f4.gif 9.055 Fig. 4: "Simplified" model of the experiment
7 table1.htm 7.494 Table 1: Material composition of zones.
8 table2.htm 2.421 Table 2: Meteorological data and nuclear concentrations
of atmospheric air elements at the period of on-site
measurements
9 table3.htm 2.678 Table 3: Characteristics of threshold detectors
10 table4.htm 3.121 Table 4: Characteristics of resonance detectors
11 table5.htm 4.636 Table 5: Characteristics of detectors used for on-site
measurements
12 table6.htm 12.001 Table 6: Radial distribution of 115In(n,n') reaction rates,
thermal neutron fluxes and photons dose rates at various
altitudes from the reactor cover
13 table7.htm 31.555 Table 7: Neutron spectrum measured by foils activation for
the RA reactor
14 table8.htm 5.647 Table 8: Neutron dose rates measured at the RA reactor
15 table9.htm 5.706 Table 9: Photon radiation dose rate measured at the RA reactor
16 table10.htm 5.708 Table 10: Thermal neutron fluxes measured at the RA reactor
17 table11.htm 5.739 Table 11: Intermediate and fast neutrons fluxes measured
at the RA reactor
18 table12.htm 7.542 Table 12: Relative count rates of spherical moderators at various
distances from the RA reactor
19 table13.htm 71.785 Table 13: Differential neutron spectra, measured by scintillation
spectrometer with a stilbene crystal at different distances from
the RA reactor
20 table14.htm 70.286 Table 14: Differential photons spectra measured by scintillation
spectrometer with a stilbene crystal at different distances from
the RA reactor
21 table15.htm 16.636 Table 15: Comparison of computed (MCNP) and experiment-determined
(Exp.) functionals of the radiation fields near the RA reactor core
22 table16.htm 6.566 Table 16: Normalized neutron and photon energy distributions for
"effective" sources
23 table17.htm 6.114 Table 17: Spatial distribution of neutron and photon dose rates,
total neutron flux and thermal neutron flux for the cases with and
without ground presence
24 table18.htm 6.427 Table 18: Comparison of computed and experiment-determined values
of neutron dose rate measured at the RA reactor
25 table19.htm 5.089 Table 19: Comparison of computed and experiment-determined values
of photon radiation dose rate measured at the RA
26 table20.htm 6.424 Table 20: Comparison of computed and experiment-determined values
of thermal neutron fluxes measured at the RA reactor
27 table21.htm 5.127 Table 21: Comparison of computed and experiment-determined values
of intermediate and fast neutron fluxes, measured at the RA reactor
28 table22.htm 8.130 Table 22: Relative counting rate of spherical moderators at various
distances from the RA reactor
29 table23.htm 9.904 Table 23: Energy dependence of sphere effectiveness for multisphere
spectrometer
30 table24.htm 2.232 Table 24: Counting rates of multisphere moderators for 252Cf source
31 table25.htm 9.955 Table 25: Comparison of neutron differential spectra calculated by
the MCNP code, with experimental data
32 table26.htm 9.551 Table 26: Comparison of photon differential spectra calculated by
the MCNP code, with the experimental data
33 sk_eranp.mcnp 26.848 Input file for MCNP, neutron + secondary photon transport
34 sk_erapp.mcnp 17.209 Input file for MCNP, primarily photon transport
35-48 im01.jpg - im15.jpg Corresponding formulae
49 skycal.pdf 149.262 Ref. [17]: Report on ANS conference, Tennessee, April 1998
50 skyexp.pdf 252.948 Ref. [18]: Report on ANS conference, Tennessee, April 1998
51 skyshine_rep.pdf 1,709,413 Ref. [19] by M.E. Netecha, et al., Compilation of the series
of Measurements of spatial energy distributions of neutrons and
photons scattered in the air near the ground-air interface in
standard SINBAD Database format.
52 517_report.pdf 1,218,021 Ref. [20]: M.E. Netecha, Final Report on ISTC Project No. 517-96,
(1998)
53 Rearsk01.pdf 1,743,437 Ref. [21]: Recommended evaluation of the benchmark (September 2009)
Figures are stored in GIF format.
SINBAD Benchmark Generation Date: 6/2006
SINBAD Benchmark Last Update: 9/2009
