cz_report_part_ii_lvr_15_irrad_test_rrrfr2013
TRANSCRIPT
Centrum vyzkumu Rez
CZECH COUNTRY REPORT PART II: LVR-15
REACTOR OPERATION AFTER HEU - LEU
CONVERSION - IRRADIATION TEST
PROJECT
Jiri Rychecky
05 June 2013
1 1
CZECH COUNTRY REPORT:
LVR-15 IRRADIATION TEST PROJECT - Introduction
Only the LEU fuel is used for reactor operation since September
2011. The purpose of this test project is to demonstrate that the
new LEU converted reactor core is able to irradiate LEU vs.
HEU materials and samples, a key capability for future use of
the research reactor.
20 operational cycles were performed since Sept. 2011 with
various core configurations
Production of NTD Si ingots have been increased more than
two times - the second NTD facility was installed on Jan.2013.
Irradiation of U targets for Mo production also increased more
than two times due the HFR Petten is temporarily shut down.
Two rigs with samples for material testing were irradiated.
View under the LVR-15 Lid
Irradiation and Experimental Facilities
The following irradiation and experimental facilities were in
operation on 2012 - 2013
Pneumatic rabbit system for activation analyses
2 facilities for Si NTD (new one was installed on Jan. 2013)
2 irradiation rigs for material testing probes
3 vertical irradiation channels for production of radioactive
isotopes (Ir, Sm, etc.) at peripheral positions
6 neutron beams (horizontal channels) for physical research
Experiments for BNCT on thermal column
Up to 4 irradiation channels for irradiation of U targets for Mo99
production inside the central neutron trap
2 irradiation channels inside Be for irradiation of Ir targets
Sept. 2011- K132 start LEU, Jan. 2012 – TW3 Rig
10
9
8
7
6
5
4
3
2
1
A B C D E F G H
core_layout [email protected]
B
B
BB
BB
B
B
B
PRB
B
B B
B
BB
B
B
B
02 03 1201 09
08
11
10
0704 0605
Ir
Ir
voidB
B
10
9
8
7
6
5
4
3
2
1
A B C D E F G H
core_layout [email protected]
B
B
B
B
B
B
B
B
B
PRB
B
B
BB
B
B
B
B
B
02 03 1201 09
08
11
10
0704 0605
Ir Ir
voidBB
EFDA TW3
Si
void void
June 2012 -K143, Dec. 2012 - K147 – NTD Si, Mo
10
9
8
7
6
5
4
3
2
1
A B C D E F G H
core_layout [email protected]
B
B
B
B
B
B
B
B
B
PRB
B
B
B
B
BB
B
B
B
02 03 1201 09
08
11
10
0704 0605
Ir
voidB
B
EFDA TW3
Si
Ir
II
I 0
Jan. 2013 - K148 - 2 Si+Mo, May 2013 - K150 – BNCT + Ir
10
9
8
7
6
5
4
3
2
1
A B C D E F G H
core_layout [email protected]
B
B
B
B B
B
B
PR
B
B
B
B
B
02 03 1201 09
08
11
10
0704 0605
Ir
Ir
B
B
B
B
B
B
B
voidBB
SPND
DN 3"
SPND
DN 4"
void
IIII
II II
10
9
8
7
6
5
4
3
2
1
A B C D E F G H
core_layout [email protected]
B
B
B
B B
B
B
PR
B
B
B
B
03 01 09
08
11
10
0704 0605
Ir Ir
B
B
B
B
B B
B void
B
B
1202
B
0
0
0
void void
SPD
SPND
DN3"
SPND
DN4"
Conclusions
During the reactor operation the condition of the fuel gladding was performed. The samples of the primary water were used for checking of non leakage of the fuel assemblies. No leakage of the fission products was detected.
The measurement of gas releases from ventilation chimney also was deeply below limits as well.
The manipulation with the IRT-4M FAs was without problems. But the manipulation has to be performed carefully because the cladding of the fuel is very thin.
The regular operation of the reactor LVR-15 with LEU was continued on 2012 - 2013. Experiences gained more than 1.5 year of operation showed that the LVR-15 operation with LEU cores is possible and the impacts are not so high except economical impacts.
Conclusions
Thermal neutrons flux was decreased about 7-10% on started
configuration with fresh fuel, but another 10% is decreasing
when the average burn was higher
Fast neutrons flux will decrease for 5 %.
It is possible to cancel losses of thermal neutrons by making
neutron traps and/or increasing reactor power by 20%. At
present research is carried out on improvement of reactor
parameters, and magnification of a thermal neutrons flux.
Irradiated U Targets for Mo99 production
Beam Tubes and BNCT Facility
Introduction
Horizontal channels generally represent one of major reactor LVR-15 utilization (their spatial disposition is visible on Fig. 2). BNCT Facility of the LVR-15 research reactor is a facility intentionally built for the development of a Boron Neutron Capture Therapy method, which is aimed at the treatment of a glioma type brain tumor. The facility consists of a neutron horizontal beam with Al and AlF3 filters (collimators), irradiation chamber and control room (see Fig. 3 and Fig. 4). The scheme of the BNCT channel can be found on Fig. 1. The whole facility is still regularly used, although medicinal research at the LVR-15 reached its peak during 2001 when five patients were irradiated as a part of clinical trial.
Fig. 1 Horizontal Channels on LVR-15
powderdiffractometer
depth profiling
n- capturestrain scanner
interferometer
boron capture therapy
SANS
texturediffractometer
10 2 m
stress/straindiffractometer
Fig. 2. The scheme of the BNCT channel
Experiments on BNCT Facility
At present, medicinal research at the BNCT beam is aimed at
study of boron deposition inside the tumor cells. Effectiveness
of different boron compounds is investigated and experiments
usually include works with living animals (young laboratory
rats) and tissue samples. Also, the beam is used mostly as a
source of neutrons for detector testing or material irradiation,
beside the medicinal research. The non-medicinal activities are
more important during several last years
BNCT Irradiation Chamber - Inside
Irradiation Chamber and Control Room - Outside
A typical spectrum for the former HEU core is visible on
the BNCT horizontal beam
BNCT NRI Beam, 14.08.2001
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01
Energy [MeV]
Neu
tro
n F
luen
ce R
ate
per
Un
it o
f L
eth
arg
y [
1/c
m^
2s]
STAYSL
SAND
Calculation
BASACF
MCNP 0 cm orig. spectrum HoIn3f
MCNP 0 cm opr. spectrum HpIn3f
Experiments on BNCT Facility (2)
The question of the impact of HEU to LEU transition to beam
energy spectrum and neutron fluence rates is very important
for the Research Centre Rez, because the information about
real dose, which irradiated sample (material) received, is
necessary for proper experiment evaluation. Most of the time, it
is also requested by customers before any official cooperation
can even start.
Active core K141, BNCT configuration, LEU fuel
Irradiation of rats on BNCT Epithermal Beam
Six day-old rats were used as biological models. Sodium
borocaptate (BSH, 100 μg 10B/g b.w.) was injected into
forebrain ventricles. 10B-phenylalanine-fructose complex (BPA)
was applied subcutaneously. Both 10B carriers were from
Katchem, Prague. Animals were irradiated in a polyethylene
holder (Fig. 8) for 5 to 7.5 min and were sacrificed anesthetized
by CO2 enriched atmosphere 8 hours or 3 days later. The
experiments were carried out in compliance with EU and Czech
legislation for animal protection. The brain and intestine were
processed by routine histological protocol and examined
microscopically.
Irradiation of rats on BNCT Epithermal Beam
Conclusion - BNCT horizontal beam
Operation of BNCT epithermal beam and results of the BNCT
beam measurement demonstrated, that the transition from HEU
enrichment to LEU enrichment brought no significant change,
which would require doing countermeasures.
The results reveal that the conversion of the reactor has only
minor influence on the spectral parameters of the beam and on
the beam intensity as well.
The very important fact is that active core K141 was not only
first LEU core designed for BNCT, but also a first BNCT LEU
core with installed central trap for molybdenum production.
Ability to simultaneously operate epithermal beam and central
trap further increases flexibility of the reactor LVR-15
utilization.
Conclusions - Final
Results of our experience show that IRT-4M type FA is quite
good and the fuel is reliable for LVR-15 operation but maybe it
is not the optimal low enriched fuel suitable especially for
economical reasons.
As U9MoAl fuel has higher density (5,40 g/cm3), than UO2-Al
(2,51 g/cm3 ), then active core could be compiled compact and
neutron flux will not decrease compared to HEU core
In connection with this, relevance of research works of UMo, or
other types of low enriched on U-235 fuel for the research
reactors remain.
Additional losses of thermal neutrons (10-20%) are expecting
after conversion of the HEU targets for Mo production
Conclusions - Final
Shortcoming of low enriched IRT-4M type FA is its smaller
inserted positive reactivity at replacement of burnt FA with a
fresh one and relative low U-235 burn up - IRT-2M type FA U-235
burn up could reach 65 %, compare IRT-4M - 45% - 50%.
IRT-4M fuel using leads to increase the price of the FA by factor
3. So, the budget for new fuel could be too high for reactor
operation from economical point of view in next years.
The next increasing of the financial demands will be also when
the reactor power would be risen up to 12 MW.
So, we can solve the technical impacts of the conversion, but
we will have difficulties to solve the economical one.
Looking into the future
Reactor power increasing up to 12 MW (2013)
Refurbishment of the I & C system (2013)
Conversion of the HEU targets for Mo production to LEU one
(2014 - 2015 )
Funding of the LVR-15 operation – looking for the new sources
and new projects (high temperature loops, irradiation for fusion
etc.)
THANK YOU FOR YOUR ATTENTION