Method for defining the concentration of fissile materials in radioactive waste
In the work the development materials of an industrial technique definition of fission materials concentration in radioactive waste are resulted. The active analysis lays on the basis of a technique. Researched samples were irradiated with flows of neutrons received on the basis of the electron line...
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| Published in: | Вопросы атомной науки и техники |
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| Date: | 2000 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2000
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| Cite this: | Method for defining the concentration of fissile materials in radioactive waste / A.Yu. Buki, V.I. Kasilov, V.V. Kirichenko, К.S. Kokhnyuk, N.I. Lapin, V.I. Noga // Вопросы атомной науки и техники. — 2000. — № 2. — С. 64-65. — Бібліогр.: 5 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859841895625129984 |
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| author | Buki, A.Yu. Kasilov, V.I. Kirichenko, V.V. Kokhnyuk, К.S. Lapin, N.I. Noga, V.I. |
| author_facet | Buki, A.Yu. Kasilov, V.I. Kirichenko, V.V. Kokhnyuk, К.S. Lapin, N.I. Noga, V.I. |
| citation_txt | Method for defining the concentration of fissile materials in radioactive waste / A.Yu. Buki, V.I. Kasilov, V.V. Kirichenko, К.S. Kokhnyuk, N.I. Lapin, V.I. Noga // Вопросы атомной науки и техники. — 2000. — № 2. — С. 64-65. — Бібліогр.: 5 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | In the work the development materials of an industrial technique definition of fission materials concentration in radioactive waste are resulted. The active analysis lays on the basis of a technique. Researched samples were irradiated with flows of neutrons received on the basis of the electron linear accelerator. Experiment was carried out on ELE - 300 NSC KIPT using neutron - making target made of Pb (5 cm in diameter and 4 cm in thickness). At an electron beam energy of 20 МeV and an average current of 1 mА such a target can produce a total neutron flux of about 2x10¹⁰s⁻¹. The achieved sensitivity by definition of concentration ²³⁵U is at the level 10⁶ g/g.
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| first_indexed | 2025-12-07T15:37:00Z |
| format | Article |
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METHOD FOR DEFINING THE CONCENTRATION OF FISSILE
MATERIALS IN RADIOACTIVE WASTE
A.Yu. Buki, V.I. Kasilov, V.V. Kirichenko, К.S. Kokhnyuk, N.I. Lapin, V.I. Noga
National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine
In the work the development materials of an industrial technique definition of fission materials concentration in
radioactive waste are resulted. The active analysis lays on the basis of a technique. Researched samples were
irradiated with flows of neutrons received on the basis of the electron linear accelerator. Experiment was carried out
on ELE - 300 NSC KIPT using neutron - making target made of Pb (5 cm in diameter and 4 cm in thickness). At an
electron beam energy of 20 МeV and an average current of 1 µА such a target can produce a total neutron flux of
about 2x1010s-1. The achieved sensitivity by definition of concentration 235U is at the level 106 g/g.
PACS: 28.41.Kw
For today’s nuclear industry, of prime importance
and urgency is the task of carrying out the analysis for
the contents of fissile material (FM) in different sort
radioactive waste (RW). This problem is particularly
pressing for Ukraine, where the development of
technologies for extraction of nuclear fuel from the
destroyed ChNPP Unit 4 is supposed.
The nuclear-physical methods of FM control are
widely diversified [1]. The most widespread are the
methods where the samples, containing the sought-for
fissile element, are activated by neutrons or γ-quanta [2−
4]. Thus the concentration of sought-for elements is
determined from the yield of prompt or delayed neutrons
from fission reactions.
Now at NSC KIPT various lines of activation
analysis are being developed to determine the isotope
composition of radioactive waste.
The purpose of the present work has been the
research into the possibility of carrying out a high-
sensitivity analysis of low 235U concentration in
industrially produced radioactive waste. The samples
were supposed to be activated with the help of neutron
flows produced from high-current electron linear
accelerator.
The experimental layout is shown in fig.1. The
parameters of the LEA-300 test bench (1) are as follows:
the electron beam energy can vary in the range Е0=0−
30 МeV, the frequency of current pulses is in the range
of f =1-100 s-1, the current pulse duration is t = 1 µs, the
average current can attain ~ 50 µА.
Fig. 1. The diagram of experiment.
An electron-irradiated lead converter (2), 5 cm in
diameter and 4 cm in thickness, served as a source of
neutrons. At an electron beam energy of 20 МeV and an
average current of 1 µА such a target can produce a total
neutron flux of about2 x1010s-1.
During the current pulse of the accelerator a neutron
flux with an energy spectrum close to Maxwell
distribution with an average energy ~ 1 МeV was
formed in the lead converter. Then followed the
moderator (3), which completely cut off the object and
the inlet aperture of the detector. The basic purpose of
the moderator was to form a flux of thermal neutrons
and thereby to create conditions for intensive fission of
235U.
The objects under study (4) represented samples of
uranium having the known isotopic structure (98 % 238U
and 2 % 235U), and surrounded by a sand mass 10 kg in
weight.
The neutron detector (5), used in experiment, was
made following the circuit of the all-wave detector [3],
64 ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2000, № 2.
Серия: Ядерно-физические исследования (36), с. 64-65.
where the counter СНМ-11 with a boron substance-
coated cathode was used for detection of thermal
neutrons.
In experiment, the delayed neutrons were registered
in the time interval of 4 − 20 ms between the current
pulses of the accelerator (f=50 s-1). In this interval the
intensity of background readout of the detector was
minimal. In this case the background readouts are those
of the detector when the accelerator is in operation but
with absence of uranium in the object under irradiation.
Two series of measurements with an interval of 12
hours were carried out; in each of them the weight of
235U in the sample was varying from 1.1 to 0.012 g.
During measurements the average current of the
accelerator was invariable and equal to 2 µА, the set of
statistics was performed for 410 s.
The results of measurements are given in fig. 2, from
which it is seen, that under specified conditions the
installation allows one to detect the presence of 235U up
to 0.012 g or the concentration up to 10-6 g/g. Besides,
there is the proportionality between the yield of delayed
neutrons and weight of 235U that confirms reliability of
measurements.
0,01 0,1 1
1
10
100
1000
N
P, g
Fig. 2. The dependence of neutrons detector indications (N) on quantity of uranium in a sample (P, g).
For checking the absence of the contribution of
delayed neutrons from 238U fission the samples under
investigation were wrapped up in a cadmium sheet 1
mm in thickness. The readout of the detector decreased
up to a level of a background, as cadmium shielded
uranium from thermal neutrons (En < 0,4 eV). It means,
that the effect observed is caused by 235U nucleus fission
with thermal neutrons, because the cross-section of this
process in the above mentioned energy is 105 - 106 more
than the cross-section of 238U fission.
The data obtained allow one to estimate the
applicability of the technique and installation under
consideration for working out the practical tasks related
to the accident at ChNPP and to atomic engineering.
The preliminary analysis shows, that the increase of
installation power not exceeding the limits of real
technical and economic feasibilities will allow
conducting the analysis of RW-samples having a weight
of hundreds kg with a limit of sensitivity to 235U not
worse than 10-7 g/g. In this case a special preparation of
samples being studied is not required.
It should be noted, that the potentialities of the
installation already in the present assembly are sufficient
for defining the concentration of 235U in nuclear fuel.
REFERENCES
1. V.V. Frolov. Nuclear-physical methods of
controlling fissile materials. M., 1998 (in Russian).
2. V.P. Kovalev. Accelearators in the nondestructing
control. M., Energoizdat, 1983 (in Russian).
3. J.R. Dherby, L.M. Deider, R. Berne, Y. Beroud.
Development active neutron devices for alpha waste
measurement in France. ENC` 90 - European
nuclear Conference Lyon (France), 23 - 27
September, 1990.
4. Y. Beroud et al. On Line analysis in spent fuel
reprocessing plant. ENC 90 - European nuclear
conference. Lyon (France), 23 - 27 September, 1990.
5. W.D. Allen, B.Sc.D. Phil. Neutron detection. M.
Atomizdat, 1962, 111 p.
REFERENCES
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| id | nasplib_isofts_kiev_ua-123456789-82285 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T15:37:00Z |
| publishDate | 2000 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Buki, A.Yu. Kasilov, V.I. Kirichenko, V.V. Kokhnyuk, К.S. Lapin, N.I. Noga, V.I. 2015-05-27T13:55:42Z 2015-05-27T13:55:42Z 2000 Method for defining the concentration of fissile materials in radioactive waste / A.Yu. Buki, V.I. Kasilov, V.V. Kirichenko, К.S. Kokhnyuk, N.I. Lapin, V.I. Noga // Вопросы атомной науки и техники. — 2000. — № 2. — С. 64-65. — Бібліогр.: 5 назв. — англ. 1562-6016 PACS: 28.41.Kw https://nasplib.isofts.kiev.ua/handle/123456789/82285 In the work the development materials of an industrial technique definition of fission materials concentration in radioactive waste are resulted. The active analysis lays on the basis of a technique. Researched samples were irradiated with flows of neutrons received on the basis of the electron linear accelerator. Experiment was carried out on ELE - 300 NSC KIPT using neutron - making target made of Pb (5 cm in diameter and 4 cm in thickness). At an electron beam energy of 20 МeV and an average current of 1 mА such a target can produce a total neutron flux of about 2x10¹⁰s⁻¹. The achieved sensitivity by definition of concentration ²³⁵U is at the level 10⁶ g/g. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Аpplication of the nuclear methods Method for defining the concentration of fissile materials in radioactive waste Метод определения концентрации делящихся материалов в радиоактивных отходах Article published earlier |
| spellingShingle | Method for defining the concentration of fissile materials in radioactive waste Buki, A.Yu. Kasilov, V.I. Kirichenko, V.V. Kokhnyuk, К.S. Lapin, N.I. Noga, V.I. Аpplication of the nuclear methods |
| title | Method for defining the concentration of fissile materials in radioactive waste |
| title_alt | Метод определения концентрации делящихся материалов в радиоактивных отходах |
| title_full | Method for defining the concentration of fissile materials in radioactive waste |
| title_fullStr | Method for defining the concentration of fissile materials in radioactive waste |
| title_full_unstemmed | Method for defining the concentration of fissile materials in radioactive waste |
| title_short | Method for defining the concentration of fissile materials in radioactive waste |
| title_sort | method for defining the concentration of fissile materials in radioactive waste |
| topic | Аpplication of the nuclear methods |
| topic_facet | Аpplication of the nuclear methods |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/82285 |
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