1. E. G. Androulakaki 1,2, G. Eleftheriou4, E. Fatsea1, M. Kokkoris1, F.K. Pappa1,2, D.L. Patiris2 , E. Skordis3,
C. Tsabaris2, R. Vlastou1
1 Department of Physics, National Technical University of Athens, Zografou Campus , Athens, Greece
2Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, Anavyssos, Greece
3European Organization for Nuclear Research (CERN), Geneva, Switzerland
4Department of Monitoring and Research, Norwegian Radiation Protection Authority, Norway
Utilization of the Monte Carlo code FLUKA for Applications in the Marine Environment
HNPS , 3-4 June 2016, Athens, Greece

2. HNPS , 3-4 June 2016, Athens, Greece
Motivation
In situ γ-spectrometry in the marine environment
Detection efficiency Monte Carlo simulations
Code selection
Aim:
Cost-effective
Time efficient
More representative
Wide field of applications
Account for True Coincidence summing (TCS) effects
FLUKA
Efficient simulation of a radioactive source
Examine FLUKA capabilities (γ/e+- transport) for environmental applications
Evaluation of the results (via MCNP-CP) in the marine environment 1
HNPS , 3-4 June 2016, Athens, Greece

3. HNPS , 3-4 June 2016, Athens, Greece
WHY FLUKA ?
FLUKA: General purpose Monte Carlo (MC) code developed at Cern
Wide range of applications (simulation of different particles)
Free software
User-friendly MC code
Efficient graphical Interface FLAIR
Geometry
Execution
Inclusion of user-defined routines
Automated simulation of a radionuclide source
Simultaneous simulations of more than one particle per event
Computing time
and effort
saving
accounts for TCS effects ! 2
HNPS , 3-4 June 2016, Athens, Greece

4. HNPS , 3-4 June 2016, Athens, Greece
WHY FLUKA ?
Graphical Interface Flair
Geometry + Execution
Easy
Import/export in MCNP format
Automated simulation of a radionuclide source
user defined routines
Sparse environmental applications
Evaluation via MCNP-CP code 3
HNPS , 3-4 June 2016, Athens, Greece

5. The MCNP-CP Monte Carlo code
Upgraded version of the general purpose Monte Carlo N- particle code MCNP (version 4b)
Evaluated for environmental applications (experimental and MC data)
Several improvements (physics, estimators (tallies))
Simulation of a Radionuclide source using the decay properties from Evaluated Nuclear Structure Data File ENSDF
instead of separate simulations for each γ-ray
Multiple particle tracking per event
TCS effects
Application: FLUKA simulations evaluation
marine environment 4
HNPS , 3-4 June 2016, Athens, Greece

6. simulation SETUP – Code differences
SAME:
MC model: (geometry, materials)
Physics settings: (interactions, energy thresholds)
Radionuclide source simulation (via a single card)
FOR non-series radionuclides
DIFFERENCES:
Radionuclide source simulation FOR series radionuclides 5
HNPS , 3-4 June 2016, Athens, Greece

7. simulation SETUP – Code differences
FLUKA Radionuclide source simulation FOR series radionuclides
EXAMPLE:
212Pb from 232Th series
Decay scheme 6
HNPS , 3-4 June 2016, Athens, Greece

8. simulation SETUP – Code differences
FLUKA Radionuclide source simulation FOR series radionuclides
EXAMPLE:
212Pb from 232Th series
212Pb
212Pb
212Bi, 208Tl
+ progenies
Decay scheme
keV
Modification of the source
routine in order to stop the decay in the first daughter nuclide
User-defined source USRMED
(available upon request) 7
HNPS , 3-4 June 2016, Athens, Greece

9. evaluation in the marine environment (check TCS simulation)
Examined test cases :
60Co, 208Tl, 212Pb
sources in the seawater
use of USRMED routine for 232Th series radionuclides
Simulation model
source
(check TCS simulation) 8
HNPS , 3-4 June 2016, Athens, Greece

10. evaluation in the marine environment results -
60Co
1.17
1.32
Sum peak
1 keV binning
to detect differences
108 events
Energy Ig
Detected Counts
Ratio
MeV %
FLUKA
MCNP-CP
1.1735
99.97
3744
3754
1.00
0.03
99.99
3638
3482
0.96 9
HNPS , 3-4 June 2016, Athens, Greece

11. evaluation in the marine environment results -
208Tl, 212Pb
(232Th series)
212Pb
106 events
Energy Ig
Detected Counts
Ratio
MeV %
FLUKA
MCNP-CP
0.075
10.41
253
303
1.20 (0.10)
0.078
17.5
310
372
1.20 (0.09)
0.088
4.01
130
152
1.17 (0.14)
0.239
43.3
1032
980
(0.04)
0.303
3.28 67 79
1.18 (0.20)
0.58
2.6
Sum peak
0.239
208Tl
108 events
Energy Ig
Detected Counts
Ratio (%)
MeV %
FLUKA
MCNP-CP
6.3
241
248
(0.09)
22.6
644
600
(0.05)
84.5
1963
1928
(0.03)
1.8 44 36
0.82 (0.18)
12.4
256
255
(0.09)
2.6145
99.0
1434
1465
1.02 (0.04) 10
HNPS , 3-4 June 2016, Athens, Greece

12. Conclusions - Perspectives
Modify FLUKA routine for series radionuclides USRMED (available)
Satisfactory agreement
Evaluation for
prominent radionuclides (naturally occurring / artificial)
different setups (seabed/ beach sand measurements)
Detection efficiency of the system KATERINA for in situ measurements on beach sands (IAEA-CRP)
FLUKA: a valuable alternative !
FUTURE WORK 11
HNPS , 3-4 June 2016, Athens, Greece

13. THANK YOU FOR YOUR ATTENTION !
Acknowledgements
Dr. A. N. Berlizov
THANK YOU FOR YOUR ATTENTION ! 12
HNPS , 3-4 June 2016, Athens, Greece