Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor
Main characteristics of the LVR-15 research reactor and its utilisation are presented in the article. Two reactor water loops for the research in the PWR environment and two water loops for the research in the BWR environment are installed at the reactor. The irradiation of specimens in the inert ga...
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| Date: | 2001 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2001
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| Cite this: | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor / Oldřich Erben, Petr Novosad // Вопросы атомной науки и техники. — 2001. — № 2. — С. 80-84. — Бібліогр.: 8 назв. — англ. |
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| author | Erben, Oldřich Novosad, Petr |
| author_facet | Erben, Oldřich Novosad, Petr |
| citation_txt | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor / Oldřich Erben, Petr Novosad // Вопросы атомной науки и техники. — 2001. — № 2. — С. 80-84. — Бібліогр.: 8 назв. — англ. |
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| description | Main characteristics of the LVR-15 research reactor and its utilisation are presented in the article. Two reactor water loops for the research in the PWR environment and two water loops for the research in the BWR environment are installed at the reactor. The irradiation of specimens in the inert gas is performed in reactor rigs of CHOUCA and slab types. The experiments are controlled with different types of sensors and reactor dosimetry is ensured. If necessary mock-up experiments for specialised experiments are performed.
В запропонованій роботі наведено основні характеристики дослідницького реактора LVR-15, а також його використання. Два водяних контури для досліджень в PWR середовищі та два водяних контури для досліджень в BWR середовищі було змонтовано в реакторі. Опромінення зразків в інертному газі виконувалось в реакторних пристроях пластинчастого типу і CNOUCA. Хід експериментів контролювався детекторами різного типу, здійснювалась також дозиметрія реактора. У разі необхідності проводяться модельні експерименти.
В статье представлены основные характеристики исследовательского реактора LVR-15, а также его использование. Два водяных контура для исследований в PWR среде и два водяных контура для исследований в BWR среде установлены в реакторе. Облучение образцов в инертном газе выполнено в реакторных устройствах пластинчатого типа и CNOUCA. Ведение экспериментов контролировалось детекторами различного типа, осуществлялась также дозиметрия реактора. По необходимости выполняются модельные эксперименты.
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РАЗДЕЛ ТРЕТИЙ
МАТЕРИАЛЫ ЯДЕРНЫХ РЕАКТОРОВ
UDC 621.039.53
REACTOR PRESSURE VESSEL AND INTERNALS STEELS
IRRADIATION PERFORMED AT THE LVR-15 RESEARCH REACTOR
Oldřich Erben, Petr Novosad
Nuclear Research Institute Řež plc, 250 68 Řež, Czech Republic,E-mail: nov@nri.cz
В запропонованій роботі наведено основні характеристики дослідницького реактора LVR-15, а також
його використання. Два водяних контури для досліджень в PWR середовищі та два водяних контури для
досліджень в BWR середовищі було змонтовано в реакторі. Опромінення зразків в інертному газі
виконувалось в реакторних пристроях пластинчастого типу і CNOUCA. Хід експериментів контролювався
детекторами різного типу, здійснювалась також дозиметрія реактора. У разі необхідності проводяться
модельні експерименти.
В статье представлены основные характеристики исследовательского реактора LVR-15, а также его
использование. Два водяных контура для исследований в PWR среде и два водяных контура для
исследований в BWR среде установлены в реакторе. Облучение образцов в инертном газе выполнено в
реакторных устройствах пластинчатого типа и CNOUCA. Ведение экспериментов контролировалось
детекторами различного типа, осуществлялась также дозиметрия реактора. По необходимости выполняются
модельные эксперименты.
Main characteristics of the LVR-15 research reactor and its utilisation are presented in the article. Two reactor
water loops for the research in the PWR environment and two water loops for the research in the BWR environment
are installed at the reactor. The irradiation of specimens in the inert gas is performed in reactor rigs of CHOUCA
and slab types. The experiments are controlled with different types of sensors and reactor dosimetry is ensured. If
necessary mock-up experiments for specialised experiments are performed.
1. LVR-15 RESEARCH REACTOR
The LVR-15 research reactor is situated in the Nu-
clear Research Institute Řež plc (further NRI). The
reactor power is of 10 MW. The reactor is operated in
21 days irradiation cycle, with 7…8 cycles per year.
The fuel assembly consists of 4 concentric tubes or 3
concentric tubes with a control rod inside the assembly.
The fuel IRT-2M contains 36 % enriched uranium.
The reactor is used as a multipurpose facility and its
main use [1] is in the following areas:
− material research carried out at reactor loops and
rigs;
− production of radiation doped silicon;
− production of radioisotopes for the radiopharma-
ceuticals and technical radiation sources;
− irradiation devices for special irradiation;
− pneumatic rabbit for activation analysis;
− development of boron neutron capture therapy at the
thermal column channel;
− neutron physics research at reactor horizontal
channels.
The irradiation facilities are complemented with
good equipped hot cells for removing irradiated speci-
mens from experimental devices and their post-irradia-
tion examination. More detail post-irradiation examina-
tion of irradiated specimens are performed in hot and
semi-hot cells situated in another building near the re-
actor [2].
In-pile irradiation research performed at reactor
loops and rigs are the most important activity carried
out at the reactor.
2. REACTOR LOOPS
This research is connected with environmental
degradation processes (corrosion, mechanical and ra-
diation effect), cladding - coolant interaction (corrosion
of zirconium alloys with and without radiation, deposi-
tion of corrosion products and effect of water chemistry
components). In-pile water chemistry and corrosion
monitoring technique (conductivity, pH, redox potential,
dissolved hydrogen and oxygen, water impurity content,
corrosion potential, contact electrical resistance etc.)
is developed and implemented at reactor loops [3]. De-
scription of loops and experiments is presented in [4],
research in the field of stress corrosion cracking of
ferritic and austenitic steels is presented in [5]
2.1. PWR Loops
Two reactor water loops RVS-3 and RVS-4 are used
for the research in the PWR environment.
The RVS-3 loop was put into operation in 1983. At
present a project of the loop reconstruction is being
prepared in order to:
− simplify the loop primary circuit;
− upgrade or replace principal loop components;
− enable experiments with real fuel elements.
The RVS-4 loop is now under functional and start-up tests.
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. № 2.
Серия: Физика радиационных повреждений и радиационное материаловедение (79), с.80-83.
80
2.2. BWR Loops
Two reactor water loops BWR-1 and BWR-2 are
used for the research in the BWR environment.
The BWR-1 loop is usually used for testing and de-
velopment of in-pile water chemistry and corrosion
monitoring technique and their components [6].
The BWR-2 loop is used for stress corrosion
cracking tests of reactor pressure vessel (RPV) and in-
ternal steels under simultaneous BWR coolant and ir-
radiation conditions. Its test channels can be used in two
modifications:
− a channel situated outside the core (with the
possibility to test specimens up to 2T CT) which is
connected with a hydrogen peroxide generation
channel (situated inside the reactor core);
− a channel situated near the core (with the possibility
to test specimens up to 1T CT).
3. REACTOR RIGS
The irradiation of specimens from reactor pressure
vessels and internals steels is being performed in reactor
rigs either of CHOUCA or slab types.
3.1. CHOUCA Irradiation Rig
The reactor rigs CHOUCA (of French production)
are used for irradiation of reactor pressure vessel mate-
rials for the research of their material properties degra-
dation under radiation. a rig specimens holder enables to
irradiate, e.g.:
− Charpy V-impact specimens;
− tensile specimens of different types up to 12 mm in
diameter;
− slow strain rate test specimens;
− fracture toughness 0.5T CT specimens.
The specimen holder consists of six sections and is
inserted in the rig heating channel (6 heating sections
are situated along the rig height and each section has its
own thermocouples) which ensures irradiation tem-
perature range from 200±10 °C to 350±10 °C in inert
gas [7]. The specimen temperatures are measured in the
specimens holder with thermocouples, and control chain
keeps the temperature distribution in the required range.
Between each holder section a carrier with neutron
monitors is situated for neutron flux and fluence deter-
mination.
In Fig. 1* a schematic drawing of the rig holder with
specimens and neutron monitors positions is presented.
3.2. Slab Rigs
Due to requirements to irradiate larger specimens a
new type of rig has been developed in NRI. Several
modifications of the rig enable the irradiation e.g.:
− up to six 1T CT specimens;
− four 2T CT specimens;
− batch of different specimens of lower dimensions
which volume lies between above mentioned
volumes.
Rigs are designed and produced for the irradiation in
the inert atmosphere of samples situated in the irra-
* All figures are placed in the Appendix.
diation volume of width up to approximately 50 mm.
There is no restriction to adapt the design and produc-
tion of the rig to the desired irradiation volume, except
that the rig length cannot exceed a limit of 510 mm, for
PIE handling reasons.
The rig has 6…8 heating sections which ensure the
irradiation temperature range from 250±10ºC to 350±10ºC
in inert gas. The specimen temperatures are measured in
the specimens holder and rig slabs with 20…30
thermocouples. 6…8 of them (one for each heating
section) are used for the heat sections control. Ar, mixture
Ar and He or He can be used as an inert gas [8].
Examples of horizontal and longitudinal cross sec-
tion of rigs are presented in Fig.2 and 3, the record of
temperature values from some thermocouples during an
irradiation cycle are presented in Fig. 4.
3.2.1. Design and production. The rig is
composed of the rig irradiation part and a
overhanging part.
In the irradiation part the specimens are situated
between two slabs, which create an irradiation cassette.
The cassette is situated in the vacuum tight box filled
with an inert gas. The box is connected with an over-
hanging part with flanges. The slabs of the cassette fulfil
two functions. On the one side they serve as a
specimens carrier, on the other side the thermocouples
and the heating cables are situated in the slabs notches.
20…30 thermocouples are used for the temperature
measurement and control. The heating cables create
three or four independent heating sections in each slab.
The thermal barrier and insulation is created with
ZrSiO4 ceramic coating made by the plasma spraying.
Two solid slabs are situated at the each side of the ir-
radiation cassette. They are tightly taken together with
screws in order to ensure a good contact of the cassette
layers and specimens. Ni is used as an insulation mate-
rial for this type of connection.
The overhanging part is formed by the holder tube
with heating elements and thermocouples leading and
inert gas inlet. It is connected with the irradiation part
with flanges. Heating cables leading go through The
vacuum tight connection box from the irradiation port
and are then led at the outer part of the holder tube
above the surface of reactor pool water. There they are
connected to the Cu leading wires which go to the con-
nector of the temperature measurement and control
system. Thermocouples are led inside the holder tube
above the surface of reactor pool water. There they are
connected to the connector of the temperature
measurement and control system. The inert gas inlet
valve is situated at the holder tube above the surface of
the reactor pool water.
3.2.2. Out-of-pile tests. Before situating the rig in
reactor, the rig situated in the special test equipment
undergoes several test to ensure a good rig operation.
These tests include helium tightness tests, stiffness test
with the gas pressure higher than the functional one,
gradual increase to maximum and then gradual decrease
of heating elements power cycles with the measurement
of thermocouple responses to the individual heating
sections power and tests of reliability, tests of
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. № 2.
Серия: Физика радиационных повреждений и радиационное материаловедение (79), с.80-83.
81
thermocouples and heating elements circuit integrity
and insulation resistance.
3.2.3. In-pile test before the irradiation. These tests
include the rig tightness tests, tests of thermocouples and
heating elements circuits connected to the measurement
and control system integrity and insulation resistance,
function of the measurement and control system.
4. REACTOR DOSIMETRY AND
TEMPERATURE DISTRIBUTION
MODEL FOR IRRADIATION
EXPERIMENTS
According to the type of experiment, different
demands on reactor dosimetry are required, ranging
from neutron spectrum, thermal and fast neutron fluxes
densities and their behaviour during the irradiation,
demanded are also final fluences and gamma radiation
heating and absorbed doses. To fulfil these demands,
several measures are taken.
− neutron flux distribution and neutron transport
calculations;
− neutron fluence monitoring with activation monitors
or self-powered neutron detectors;
− gamma heating calculations;
− gamma heating monitoring with reactor calori-
meters;
− mock-up experiments.
4.1. Neutron Fluence Monitoring
Neutron flux monitors are situated in different parts
of the rig irradiation volume to determine the target
neutron fluence values.
For a long term irradiation two carriers with neutron
flux monitors situated in tubes (see Fig.3) outside the rig
are used for neutron fluence monitoring. After certain
period of irradiation the carriers are withdrawn, and
replaced by new carriers with fresh neutron fluence
monitors. From irradiated neutron fluence monitors a
received fluence is determined and plan for further ir-
radiation is elaborated. For CHOUCA rigs self-powered
neutron monitors situated near the rig are used for the
neutron fluence monitoring.
The following materials ad interactions can be used
for the neutron irradiation parameters determination:
54Fe(n,p)54Mn, 58Fe(n,γ)59Fe, 46Ti(n,p)46Sc, 63Cu(n,α)60Co,
58Ni(n,p)58Co, 59Co(n,γ)60Co, 93Nb(n,γ)94Nb, 93Nb(n,n´)93Nb.
The monitors are used in the form of foils or wires and
delivered by JRCM-IRMM, Geel, Belgium, or sets of
monitors encapsulated from NRG Petten, The Netherlands.
4.2. Calculation codes
The power and neutron group flux densities distri-
bution in the core are calculated with the NODER 4
groups diffusion code developed in the NRI. The
macroscopic constants for this code are prepared with
the use of WIMSD4 and WIMSD4-M codes. The
WIMS code is also used for the calculation of the flux
density detail distributions in the irradiation devices.
Fast neutron spectra, neutron flux densities and
gamma heating are determined using the ANISN,
DORT transport computer codes with the BUGLE-96
coupled cross section library of 47 neutron and 20
gamma groups, MCNP and KENO V, a Monte Carlo
codes with ENDF/B VI cross section library.
For temperature distribution across the rig a com-
puter code was developed in NRI. The code solve the
Laplacean heat conduction equation together with the
boundary conditions by the finite differences method.
Boundary conditions take also into account the
resistances between rig outer slabs and the reactor
cooling water as well as heat resistances rig slabs and
the ZrSiO4 insulation layers.
4.3. Mock-up Experiments
When a new type of irradiation experiment should
be carried out, or when the irradiation equipment posi-
tion in the reactor core could be quite different then
those used during the preceding experiments, a mock up
experiment is carried out. For this experiment a model
of irradiation assembly with dummy samples is pro-
duced and it contains an appropriate amount of activa-
tion monitors and thermocouples are situated in the
places of interest. In this experiment the calculated
neutron spectrum is verified, neutron flux densities dis-
tribution in the irradiation assembly are determined and
also relations to the neutron monitors situated outside
the irradiation equipment are determined.
From thermodynamical measurements the data are
generated concerning the gamma heating and tempera-
ture distribution across the rig as well as final design of
the insulation layers profile along the reactor core height
in order to keep the required irradiation temperature.
When an outer calorimeter string is used for the
gamma radiation absorbed dose rate monitoring, the
mock up experiment includes also the measurement
with a calorimeters inside the irradiation channel.
5. CONCLUSION
Reactor rigs in NRI enable irradiation in inert gas
batches of samples with dimension up to 2T CT with
the irradiation temperature range from 250±10°C to 350
±10 °C. Reactor loops can be used for the material
studies both in PWR and BWR environment.
REFERENCES
1. J.Kysela. Irradiation Services Provided by the LVR-
15 Research Reactor // Nucleon. 1995, №2, p. 35-37.
2. V.Kraus et al. Semi-hot Experimental Facilities and
Methods Employed in Mechanical Testing Programs for
PWR Pressure Vessel Steels // Nucleon. 1993, №3-4,
p. 36-40.
3. J.Kysela et al. In-pile Irradiation Research at NRI Řež
for Corrosion and Material Testing // Nucleon. 1995,
№1, p. 4-7.
4. J.Kysela et al. Research Facilities of LVR-15
Research Reactor // Proceedings of the ENS Topical
Meeting on Research Facilities for the Future of
Nuclear Energy, Brussels, 4-6 June 1996, p. 154-161.
5. M.Ruščák et al. Stress Corrosion Cracking Tests of
RPV Steels under Simultaneous BWR Coolant and Irra-
diation Conditions // 9th International Symposium on
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. № 2.
Серия: Физика радиационных повреждений и радиационное материаловедение (79), с.80-83.
82
Environmental Degradation of Materials Power Sys-
tems-Water Reactors, Newport Beach, 1-4 August 1999.
6. M.Sakai. MTR Irradiation and In-situ ECP Measu-
rement of Ceramic/Metal BWR Water Chemistry Ana-
lysis Sensors // ANERI (Japan) Final Report, Feb.
2000.
7. M.Andrejsek et al. Irradiation Facilities for Material
Testing on the LVR-15 Reactor // Nucleon. 1995, №3-4,
p. 41-42.
8. J.Svoboda et al. Flat Irradiation Rigs // Nucleon.
1998, №3, p. 29-30.
Fig.1. CHOUCA MT samples and neutron fluence monitors carrier
Fig. 2. Irradiation rig 1T CT crossections
Fig.3. Irradiation rig 2T CT crossections
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. № 2.
Серия: Физика радиационных повреждений и радиационное материаловедение (79), с.80-83.
83
APPENDIX
Fig. 4. Record of temperature values from some thermocouples during an irradiation cycle
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. № 2.
Серия: Физика радиационных повреждений и радиационное материаловедение (79), с.80-83.
84
1. LVR-15 Research Reactor
2. Reactor Loops
2.1.PWR Loops
2.2.BWR Loops
3. Reactor Rigs
3.1.CHOUCA Irradiation Rig
3.2.Slab Rigs
3.2.1. Design and production. The rig is composed of the rig irradiation part and a overhanging part.
4. Reactor Dosimetry and Temperature Distribution Model for Irradiation Experiments
4.1.Neutron Fluence Monitoring
4.2.Calculation codes
4.3.Mock-up Experiments
5.Conclusion
|
| id | nasplib_isofts_kiev_ua-123456789-78313 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T17:10:13Z |
| publishDate | 2001 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Erben, Oldřich Novosad, Petr 2015-03-13T19:10:06Z 2015-03-13T19:10:06Z 2001 Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor / Oldřich Erben, Petr Novosad // Вопросы атомной науки и техники. — 2001. — № 2. — С. 80-84. — Бібліогр.: 8 назв. — англ. 1562-6016 https://nasplib.isofts.kiev.ua/handle/123456789/78313 621.039.53 Main characteristics of the LVR-15 research reactor and its utilisation are presented in the article. Two reactor water loops for the research in the PWR environment and two water loops for the research in the BWR environment are installed at the reactor. The irradiation of specimens in the inert gas is performed in reactor rigs of CHOUCA and slab types. The experiments are controlled with different types of sensors and reactor dosimetry is ensured. If necessary mock-up experiments for specialised experiments are performed. В запропонованій роботі наведено основні характеристики дослідницького реактора LVR-15, а також його використання. Два водяних контури для досліджень в PWR середовищі та два водяних контури для досліджень в BWR середовищі було змонтовано в реакторі. Опромінення зразків в інертному газі виконувалось в реакторних пристроях пластинчастого типу і CNOUCA. Хід експериментів контролювався детекторами різного типу, здійснювалась також дозиметрія реактора. У разі необхідності проводяться модельні експерименти. В статье представлены основные характеристики исследовательского реактора LVR-15, а также его использование. Два водяных контура для исследований в PWR среде и два водяных контура для исследований в BWR среде установлены в реакторе. Облучение образцов в инертном газе выполнено в реакторных устройствах пластинчатого типа и CNOUCA. Ведение экспериментов контролировалось детекторами различного типа, осуществлялась также дозиметрия реактора. По необходимости выполняются модельные эксперименты. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Материалы ядерных реакторов Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor Article published earlier |
| spellingShingle | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor Erben, Oldřich Novosad, Petr Материалы ядерных реакторов |
| title | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor |
| title_full | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor |
| title_fullStr | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor |
| title_full_unstemmed | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor |
| title_short | Reactor Pressure Vessel and Internals Steels Irradiation Performed at the LVR-15 Research Reactor |
| title_sort | reactor pressure vessel and internals steels irradiation performed at the lvr-15 research reactor |
| topic | Материалы ядерных реакторов |
| topic_facet | Материалы ядерных реакторов |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/78313 |
| work_keys_str_mv | AT erbenoldrich reactorpressurevesselandinternalssteelsirradiationperformedatthelvr15researchreactor AT novosadpetr reactorpressurevesselandinternalssteelsirradiationperformedatthelvr15researchreactor |