4th International Workshop on Accelerator Radiation Induced Activation (ARIA'17)

22 May 2017, 08:30 → 24 May 2017, 19:40 Europe/Stockholm

Gästmatsalen (Medicon Village)

 

The fourth International Workshop on Accelerator Radiation Induced Activation (ARIA’17) will be held on May 22-24, 2017 in Lund, Sweden.

The workshop will follow ARIA’08 held at PSI, Switzerland in 2008, ARIA’11 held at Kibbutz Ma’ale HaChamisha, Israel in 2011 and ARIA’15 held at Knoxville, USA in 2015.

The purpose of these topical ARIA meetings is to provide an international forum for discussing the various problems of radionuclide transmutation in various applications at accelerator facilities.

The workshop provides an opportunity for nuclear physicists, accelerator physicists, nuclear engineers, and other experts in the international community to meet and discuss directly their research activities. These interactions can help establish good working relationships and collaborations to solve common problems across multiple disciplines related to neutron- and accelerator-induced activation.

The technical program will consist of a consecutive session of oral and poster presentations.

You are cordially invited to participate in ARIA’17 by submitting an abstract (200 word limit), making an oral or poster presentation, and submitting a full paper (10 pages or less) for publication in our workshop proceedings.

We plan to offer a one-afternoon tour of the ESS (European Spallation Source) site.

 

 

Contact: Aria17@esss.se

 

Poster ARIA_LOGO_(with_topics).png

Monday, 22 May

08:30 → 09:00 Registration

09:00 → 09:20 Opening

09:20 → 11:10 Reaction models, Programs and Data libraries

Conveners: Dr Jean-Christophe Sublet (United Kingdom Atomic Energy Authority), Dr Stuart Ansell (European Spallation Source ERIC)

09:20 Nuclide production in spallation reactions: How useful are the simulations?

INCL (Liège IntraNuclear Cascade model) combined with a deexcitation code has been used a lot for numerous simulations of spallation reactions during the last two decades. We go back over some of those simulations to address the capabilities of such codes and to show some improvements. The four examples of simultation are: the EURISOL project, the MEGAPIE target, the ESS facility, and the cosmogenic nuclide production. The goal is to discuss respectively designing and optimisation, predictive power and reliability, feasibility and uncertainty estimate, and the use of modeling to mitigate lack of experimental data.

Speaker: Dr Jean-Christophe David (CEA)

Slides jcdavid-aria17.pptx

09:40 FISPACT-II & TENDL: developments to model high-energy activation, transmutation processes and radiation damage source terms

J-Ch. Sublet, M. Fleming, M. R. Gilbert and A. Koning* UK Atomic Energy Authority, Culham Science Centre, Abingdon OX14 3DB, United Kingdom *International Atomic Energy Agency, Vienna International Centre, 1400 Vienna, Austria The inventory code FISPACT-II is a powerful simulation system for modeling activation, transmutation processes and simulating radiation damage sources terms. When coupled with complete nuclear data forms including the TENDL neutron and charged particle induced reaction libraries, GEF energy-dependent fission yield files and full TALYS/spectra-PKA knock-on atom spectra, FISPACT-II can provide robust, predictive calculations for a large variety of applications. It has been extensively tested and also benefits from the feedback from wide-ranging validation and verification activities. The system has extended nuclear data forms and new software. FISPACT-II, written in object-style Fortran to provide new capabilities for the simulation of activation, transmutation, depletion and burnup, while following full decay paths and generating radiation damage and source terms. The latest FISPACT-II code has allowed us to implement many more features, including an extended energy range, up to GeV; incident particles: alpha, gamma, proton, deuteron and neutron; primary knock on atoms spectra and more neutron physics: self-shielding effects, temperature dependence, thin and thick target yields, pathways analysis, detailed inventory, sensitivity and error estimation using covariance data. These extended capabilities better cover accelerator particles physics, astrophysics, and material sciences. The TENDL data forms pushed to the GeV incident includes extended spallation products as well as open fission channel on non-actinides. These are complemented with GEFY fission yields for 109 targets and GEF-based energy dependent fission yields for others of interest. With the ability to account for all isomers, including those as target (1 sec. half-life minimum) and daughter (0.1 sec.), TENDL provides FISPACT-II with the ability to calculate robust time dependent inventories without omissions. http://fispact.ukaea.uk/ http://www.sciencedirect.com/science/article/pii/S0090375217300029

Speaker: Dr Jean-Christophe Sublet (United Kingdom Atomic Energy Authority)

Slides jcs_f2_tendl.pdf

10:30 High-Energy Activation Simulation Coupling TENDL and SPACS

The TENDL-2015 neutron and charged-particle nuclear data files cover some 2809 targets with complete reaction data including all emitted particles for incident energies up to 200 MeV. These data are contained within the international standard ENDF-6 format, with full product energy-angle (MF6) data that can be processed into production cross-section (MF10) data and utilised by codes such as FISPACT-II for activation simulation. The driving engine behind TENDL, the TALYS code, performs sophisticated optical model calculations to predict the cross sections for each of these yields, which incurs significant computational expense and (even with the most recent, advanced data) cannot easily provide data for the full spallation yield ‘tail’ including nucleon differences in excess of a few dozen. As with fission yields, the use of other software (e.g. GEF) is standard practice to complement data for other physical processes. To generate the full tabulated data required for activation simulations, the semi-empirical isotopic spallation simulation code SPACS was utilised to build complete isotopic yield (MF8) data files for incident neutrons and protons with energies from 100 MeV to a few GeV, in the same format as with fission yields. These can be read directly into the FISPACT-II code and used with the complete nuclear reaction data of TENDL to provide a consistent simulation framework including high-energy activation residual products down to approximately half of the target mass. These are complemented with GEF-based fission yield files to build a robust, tabulated-data activation/transmutation system for incident energies up to the GeV range.

Speaker: Dr Michael Fleming (UK Atomic Energy Authority)

Slides ARIA17_MFleming.pptx

10:50 Development fast generic activation code for high-complexity models

MCNP(X) Monte Carlo neutronic modeling has now reached the level that large simulations of spallation sources from proton beam to instrument detectors and shielding, or reactor core to detectors, in which the majority of the engineering aspect (e.g. pipework) are described in detail. Directly building an MCNP(X)'s input for a large geometry, is highly time consuming and almost all the features of MCNP(X) that allow that process to be made simpler for the user (e.g. universes, lattices etc) reduce the simulation runtime performance by orders of magnitude. CombLayer is a toolbox designed to facilitate the rapid production of complex MCNP(X) models that depend on a long list of ranged variables and a number of module flags. However, to further develop this, we report in this paper on the development of automated activation calculation for highly complex models. We have combined this with Cinder and MCNP to produce a rapid gamma emission flux for a desired volume, without requiring the user to consider the volumes contents. There are two elements for such a program: first a significant part of bookkeeping to manage several thousand individual material cells separate, and second the overlay of a mesh flux to create a flux density gradient within cells that have large variation of flux within an individual cell. This mesh is then used in combination of the cell based cinder output to populate the gamma emission volume, passed back to MCNP(X) to produce a gamma dose map at the correct time step after irradiation A few examples from the ESS and ISIS beamlines will be shown to show highlight features that would be easily overlooked in a more traditional cell by cell approach. The code is publicly available at https://github.com/SAnsell/CombLayer.

Speaker: Dr Stuart Ansell (European Spallation Source ERIC)

Slides Aria_StuartAnsell.pdf

10:00 → 10:30 Coffee Break

11:10 → 11:50 Cross section measurements and intercomparison

Convener: Dr Jean-Christophe David (CEA)

11:10 Activation yields of proton-induced nuclear reactions on bismuth up to 100 MeV

Activation yields of 209Bi(p, xn)207,206,205,204,203Po, and 209Bi(p, pxn) 207,206,205,204,203Bi reactions were measured up to 100 MeV to verify the Monte Carlo codes, FLUKA, MARS, and PHITS. In addition, the gap in the excitation functions of abovementioned radio-nuclei was filled. The target was arranged in a stack consisting of Bi, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using 27Al(p, 3pn)24Na, 197Au(p, pn)196Au, and 197Au(p, p3n)194Au monitor reactions in parallel as well as Gafchromic film dosimetry method. The activities of produced radio-nuclei in the foils were measured by HPGe spectroscopy system. A good agreement was observed between the present experimental data and the previously published data. The ratios of the results of calculations by the codes to the measured activation yields of Po radio-nuclei did not exceed 1.3 over the whole beam range. In the case of Bi radio-nuclei, ratios were less than 1.4 except for 204Bi radionuclide of which was 2.3. In conclusion, a satisfactory agreement was observed between the present experimental data and the simulations.

Speaker: Dr Leila Mokhtari Oranj (Division of Advanced Nuclear Engineering, POSTECH, Pohang 37673, Republic of Korea)

Slides ARIA17_leila.pptx

11:30 Proton induced activity in graphite – comparison between measurement and simulation

The Paul Scherrer Institut (PSI) operates the Meson production target stations E and M with 590 MeV protons of up to 2.4 mA. Pions and muons are produced in these targets for research in particle physics and for muon spin-resonance applications (muSR). The effective thickness of Target E is 4 cm or 6 cm. Both targets E and M consist of polycrystalline graphite and rotate with 1 Hz due to the high power deposition of 40 kW (2 mA) for the 4cm thick Target E. The graphite wheel is regularly exchanged and disposed as radioactive waste after a maximum of 3 years in operation, which corresponds to about 30 Ah. For the disposal, the nuclide inventory of the long-lived isotopes (T1/2 > 60 d) has to be known. A small number of gamma emitters, which are mainly induced by impurities in graphite, were measured with the High-Purity Germanium detector. 3H, 14C measurements were carried out using Liquid Scintillation Counting techniques after chemical treatment. The measured specific activities will be compared against values from a coupling of Monte Carlo particle transport simulations performed with MCNPX2.7.0 and buildup/decay calculations performed with FISPACT 10.

Speaker: Dr Daniela Kiselev (Paul Scherrer Institut)

Slides ARIA17_Nucinv_graphite.pptx

11:50 → 14:40 Benchmarking and intercomparison

Convener: Dr Goran Skoro (ISIS Neutron and Muon Source, Science and Technology Facilities Council)

11:50 Activation of the ISIS TS-1 and TS-2 targets - Simulations versus experimental results -

The calculations of the radioactive inventories (and related quantities such as gamma dose rates, decay heat, etc.) of irradiated Target Station 1 (TS-1) and Target Station 2 (TS-2) targets at ISIS Neutron and Muon Source have significant operational and safety impact. These calculations are required to facilitate target disposal exercises but also to understand (by comparing simulations results with corresponding measurements data) details about target(s) activation which could help in, for example, planning the upgrade of existing target systems. In this paper, the details about ISIS targets geometries, their irradiation histories, simulation procedures, obtained results and comparison with measurement results (gamma dose rates and gamma spectra of used targets) will be presented.

Speaker: Dr Goran Skoro (ISIS Neutron and Muon Source, Science and Technology Facilities Council)

Slides TS1-2_Targ_Act_GSkoro_ARIA2017.pptx

12:10 Measurements and FLUKA Simulations of Bismuth , Aluminium and Indium Activation at the upgraded CERN Shielding Benchmark Facility (CSBF)

Authors: P. Bamidis$^{1}$, M. Brugger$^{2}$, R. Froeschl$^{2}$, **E. Iliopoulou**$^{1,2}$, A. Infantino$^{2}$, T. Kajimoto$^{3}$, N. Nakao$^{4}$, S. Roesler$^{2}$, T. Sanami$^{5}$, A. Siountas$^{1}$, H. Yashima$^{6}$ $^{1}$ Medical Physics Laboratory, School of Medicine, Aristotle University of Thessaloniki, Greece, $^{2}$ CERN,$^{3}$ Hiroshima University, $^{4}$ Shimizu Corporation,$^{5}$ KEK, $^{6}$ Kyoto University The CERN High energy AcceleRator Mixed field (CHARM) facility is situated in the CERN Proton Synchrotron (PS) East Experimental Area. The facility receives a pulsed proton beam from the CERN PS with a beam momentum of 24 GeV/c with 5E11 protons per pulse with a pulse length of 350 ms and with a maximum average beam intensity of 6.6E10 protons per second. The extracted proton beam impacts on a cylindrical copper target. The shielding of the CHARM facility includes the CERN Shielding Benchmark Facility (CSBF) situated laterally above the target that allows deep shielding penetration benchmark studies of various shielding materials. This facility has been significantly upgraded during the extended technical stop at the beginning of 2016. It consists now of 40 cm of cast iron shielding, a 200cm long removable concrete block with 3 inserts for activation samples, a material test location that is used for the measurement of the attenuation length for different shielding materials as well as for sample activation at different thicknesses of the shielding materials. Activation samples of bismuth, aluminium and indium were placed in the CSBF in September 2016 to characterize the upgraded version of the CSBF. Monte Carlo simulations with the FLUKA code have been performed to estimate the specific production yields of bismuth isotopes ($^{206}$Bi, $^{205}$Bi, $^{204}$Bi, $^{203}$Bi, $^{202}$Bi, $^{201}$Bi) from $^{209}$Bi,$^{24}$Na from $^{27}$Al and $^{115m}$I from $^{115}$I for these samples. The production yields estimated by FLUKA Monte Carlo simulations are compared to the production yields obtained from $\gamma$-spectroscopy measurements of the samples taking the beam intensity profile into account. The agreement between FLUKA predictions and $\gamma$-spectroscopy measurements for the production yields is at a level of a factor of 2.

Speaker: Ms Elpida Iliopoulou (CERN)

Slides 20170522_ARIA17_Iliopoulou.pptx

14:00 Benchmark studies of spallation products in Cu target irradiated by high-energy heavy ions

The activation analysis for heavy-ion accelerator is important issues but the experimental data are limited. In this work the ability of several Monte Carlo codes to predict spallation products in thick Cu target were investigated by benchmarking calculations. FLUKA, PHITS/DCHAIN-SP, and MCNPX/FISPACT were tested. The depth profile of spallation products in thick Cu target irradiated by protons (100, 230 MeV), C ions (100, 230, 400 MeV/n), Ar ions (230, 400 MeV/n) and 238U ions (500 MeV/n) were calculated using the Monte Carlo codes and compared with earlier works. For 238U ions on Cu target, the fragment yields of 46Sc, 51Cr, 56Fe, 52,54Mn and 56,57,58Co of target nuclei were investigated. In the case of C and Ar ions on Cu, fragment yields of 7Be, 22Na, 38Cl, 49Cr, 56Mn, and 61Cu of target nuclei as well as projectile were calculated. A Relativistic Quantum Molecular Dynamics (RQMD) model in FLUKA, JAERI Quantum Molecular Dynamics (JQMD) and Generalized Evaporation Model (GEM) in PHITS, and a Los Alamos Quark-Gluon String Model (LAQGSM) in MCNPX were benchmarked. A good agreement was observed between calculations and experimental data, at the beginning of depth of Cu target. In general, FLUKA results were closer to the experimental data than other codes for the incident 238U ions and Ar ions on Cu. In the case of C ions, the discrepancy between calculations and experimental data becomes smaller with increase in the incident ions energy. The estimation properties of each Monte Carlo codes were discussed finally.

Speaker: Dr Hee-Seock Lee (Pohang Accelerator Laboratory, POSTECH)

Slides ARIA4_ActBench_HSLee1.pdf

14:20 Sensitivity of Ambient Dose Equivalent to the Concentration of Cobalt Impurity Present in Stainless Steel

Stainless steels contain nickel in large amounts (~ 8 %) to improve its corrosion and heat resistance. Traces of cobalt are present in nickel, which are hard to separate because of its chemical similarity. Therefore, cobalt content in steel is restricted to a maximum of 2 parts per mille for applications in nuclear industry, as natural cobalt (composed of 100% Co-59) transmutes into highly radioactive Co-60 by absorbing a thermal neutron. Co-60 has a rather long half-life of 5.3 years decaying to stable Ni-60 by emitting 2 gammas of 1.17 MeV and 1.33 MeV during the process. These hard gammas will be mostly responsible for the dose rates seen in the next few tens of years. Therefore, it is important to consider the activation of cobalt in steel and estimate the dose contributed by it. Monte Carlo simulations are performed where stainless steel samples with different cobalt concentrations are irradiated with thermal and epithermal neutrons. The ambient dose equivalent, H*(10) from irradiated samples is found to be linearly proportional to the concentration of cobalt. This paper explains the motivation, the procedure, and the detailed results of the simulations.

Speaker: Dr Nikhil Shetty (ELI Beamlines)

Slides abstract-ARIA_nshetty.pdf

12:30 → 14:00 Lunch Break

14:40 → 15:40 Radiological characterization: Methods

Convener: Masatoshi Arai (European Spallation Source ERIC)

14:40 A method for radiological characterization based on fluence conversion coefficients

Radiological characterization of components in accelerator environments is often required to ensure adequate radiation protection during maintenance, transport and handling as well as for the selection of the proper disposal pathway. The relevant quantities are typical the weighted sums of specific activities with radionuclide-specific weighting coefficients. Traditional methods based on Monte Carlo simulations are radionuclide creation-event based or the particle fluences in the regions of interest are scored and then off-line weighted with radionuclide production cross sections. The presented method bases the radiological characterization on a set of fluence conversion coefficients. For a given irradiation profile and cool-down time, radionuclide production cross-sections, material composition and radionuclide-specific weighting coefficients, a set of particle type and energy dependent fluence conversion coefficients is computed. These fluence conversion coefficients can then be used in a Monte Carlo transport code to perform on-line weighting to directly obtain the desired radiological characterization, either by using built-in multiplier features such as in the PHITS code or by writing a dedicated user routine such as for the FLUKA code. The presented method has been validated against the standard event-based methods directly available in Monte Carlo transport codes.

Speaker: Dr Robert Froeschl (CERN)

Slides Froeschl_ARIA2017_20170522_cern.pdf

15:00 ActiWiz3 – an overview of the latest developments and their application

In 2011 the ActiWiz code was developed at CERN in order to optimize the choice of materials for accelerator equipment from a radiological point of view. Since then the code has been extended to allow for calculating complete nuclide inventories and provide evaluations with respect to radiotoxicity, inhalation doses, etc. Until now the software included only pre-defined radiation environments for CERN’s high-energy proton accelerators which were based on FLUKA Monte Carlo calculations. Eventually the decision was taken to invest into a major revamping of the code. Starting with version 3 the software is not limited anymore to pre-defined radiation fields but within a few seconds it can also treat arbitrary environments of which fluence spectra are available. This has become possible due to the use of ~100 CPU years’ worth of FLUKA Monte Carlo simulations as well as the JEFF cross-section library for neutrons < 20 MeV. Eventually the latest code version allowed for the efficient inclusion of 42 additional radiation environments of the LHC experiments as well as considerably more flexibility in view of characterizing also waste from CERN’s Large Electron Positron collider (LEP). New fully integrated analysis functionalities like automatic evaluation of difficult-to-measure nuclides, rapid assessment of the temporal evolution of quantities like radiotoxicity or dose-rates, etc. make the software a powerful tool for characterization complementary to general purpose MC codes like FLUKA. In this paper an overview of the capabilities will be given using recent examples from the domain of waste characterization as well as operational radiation protection.

Speaker: Dr Christian Theis (CERN)

Slides ActiWiz-ARIA_2017.pptx

15:20 Strategy of Instrument Shield at Spallation Source - experiences at J-PARC

Neutronics calculation is a key component to design radiation facility. There are well established and reliable codes for radiation transportation calculation, such as MCNPX, GEANT4, PHITS, etc. Shielding design to keep the dose rate lower than regulation is of the main importance. However, at neutron scattering facility radiation will not be contained just within a shield of source, but a large fraction of neutrons needs to be lead out to instruments, with diminishing high energy neutrons and gammas as much as possible. Because of this situation a holistic view/analysis of radiation field is very important to make the facility safe and functional. Accelerator system can be well separated from the target station and instrument. Proton beam is injected to the target, but radiation from accelerator itself cannot make any substantial effect to those other component. On the other hand radiation created at the target should be well shielded by the monolith biological shield, and at the same time a large fraction of radiation, neutrons and gammas, go out the monolith and are transported to instrument. Therefore, Holistic radiation analysis is indispensable for the success of the facility. Neutron instruments sometimes have a long flight path, ~100m, and it is a quite difficult task to perform simulation through whole path. So, some innovative technique would be necessary. In this talk, I will show you how instrument beam line shield calculation and design was performed at J-PARC, and how we achieved very low background as well as radiation dose field with a very cost effective way.

Speaker: Masatoshi Arai (European Spallation Source ERIC)

Slides ARIA_Beam_Line_Shield_at_J-PARC_MA__final_V3.0.pptx

16:00 → 18:00 Welcome event

Tuesday, 23 May

08:30 → 09:00 Registration

09:00 → 11:30 Design studies

Convener: Stefan Roesler (CERN)

09:00 Induced activation studies for the LHC upgrade to High Luminosity LHC

The Large Hadron Collider (LHC) will be upgraded in 2019/2020 to increase its luminosity (rate of collisions) by a factor of five beyond its design value and the integrated luminosity by a factor ten, in order to maintain scientific progress and exploit its full capacity. The novel machine configuration, called High Luminosity LHC (HL-LHC), will increase consequently the level of activation of its components. The evaluation of the radiological impact of the HL-LHC operation in the Long Straight Sections of the Insertion Region 1 (ATLAS) and Insertion Region 5 (CMS) is presented. Using the Monte Carlo code FLUKA, ambient dose equivalent rate estimations have been performed on the basis of two announced operating scenarios and using the latest available machine layout. The HL-LHC project requires new technical infrastructure with caverns and 300 m long tunnels along the Insertion Regions 1 and 5. The new underground service galleries will be accessible during the operation of the accelerator machine. The radiological risk assessment for the Civil Engineering work foreseen to start excavating the new galleries in the next LHC Long Shutdown and the radiological impact of the machine operation will be discussed.

Speaker: Dr Cristina Adorisio (CERN)

Slides 1_Adorisio.pptx

09:20 Development of Compact Accelerator Neutron Source

In the next decade, the neutron community will have to face with the programmed shut-down of major fission-based neutron sources in Europe. This will reduce the Europe capacities to produce neutrons for major industrial or societal challenges such as nuclear data measurements for nuclear industry, fundamental solid state physics studies with neutron scattering experiments, neutron radiography especially for industrial materials qualification and also medical purposes such as isotope production or neutron-capture therapy. An envisaged strategy to partly compensate this loss is to build small scale or regional neutron sources devoted to specific applications based on the accelerator technology. The (p,xn) or (d,xn) reactions using low-energy proton or deuteron beams impinging on a Lithium or Beryllium target can produce efficiently neutrons, whose its energy has to be convert in the specific energy range of the dedicated application (thermal and/or epithermal energy). In CEA, we have launched the SONATE project [1, 2] that aims to study and develop a compact neutron source based on high-intensity proton beams. Dealing with high-intensity beams, many challenges appear, especially the heat removal of the target that is a limiting parameter for the beam intensity. The optimization of the target/moderator assembly is a key ingredient to maximize the neutron transport onto the instrument/sample. This optimization should be done taking into account the heat removal problem and the neutron features required by the users as for example the energy-pulse, the brightness and the shaping-time of the pulse. All these points could only be addressed by using validated and predictive Monte-Carlo simulations and require reliable nuclear data on the primary nuclear reactions both on the Li(p,n) and Be(p,n) reactions. Using the IPHI accelerator in Saclay we already have validated the Geant4 simulation with 3MeV proton on Be target and a polyethylene moderator, showing the sensitivity to the neutron angular distribution. After a short review of CANS (Compact Accelerator Neutron Source) developments in the world, I will present the validation of the GEANT4-based simulation tool in terms of nuclear model point of views, as well as its application for the development of a prototype in Saclay. [1] A. Letourneau et al., to be published in EPJ Web of Conferences ND 2016, Bruges (Belgium), 2016 [2] H.N. Tran et al., to be published in Proc. Conf. SATIF-13, Dresden (Germany), 2016

Speaker: Dr Anthony MARCHIX (Irfu/SPhN, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette)

Slides 2_Marchix.pptx

09:40 Study of the collimators for curved beamline at ESS

The ESS is being constructed in Lund, Sweden and is planned to be the world’s brightest pulsed spallation neutron source for cold and thermal neutron beams (< 1 eV). The facility uses a 2 GeV proton beam to produce neutrons from a tungsten target. The neutrons are then moderated in a moderator assembly consisting of both liquid hydrogen and water compartments. Surrounding the moderator are 22 beamports, which view the moderator's outside surfaces. The beamports are connected to long neutron guides that transport the moderated neutrons to the sample position via reflections down neutron guides. As well as the desired moderated neutrons, fast neutrons coming directly from the target can find their way down the beamlines. These can create unwanted sources of background for the instruments. To mitigate such a kind of background, several instruments will use curved guides to lose direct line-of-sight (LoS) to the moderator and the target. Once LoS is lost it is necessary to suppress the fast neutrons that are still traveling along the guide due to albedo reflections or streaming. One of the better solutions is the use of collimator blocks around the guide. Several different materials have been proposed for this purpose. The choice of material is a compromise between the efficiency of removing the background, the cost, and the activation of the material. The last point is particularly important, since many of the collimators are planned to be located in a common shielding structure, which extends from the outer surface of the monolith, located at 5.5m from the target, to 15 m for the short instrument sector and to 28m in the long instrument sectors. Rapid access to the equipment in this area is required, for performing maintenance and repairs. For this reason, the optimisation of the activation level is a key activity in the project. We present the results of a study of several different options for collimators, and identify the optimal choices that balance cost, background and activation levels.

Speaker: Dr Valentina Santoro (European Spallation Source ERIC)

Slides 3_Santoro.pptx

10:30 A Monte Carlo study on neutron activation in neutron detectors with Ar/CO2 counting gas

Monte Carlo simulations using MCNP have been performed in order to study the effect of neutron activation in Ar/CO$_{2}$ neutron detector counting gas, from the perspective of decay gamma as well as prompt gamma production. A general model for neutron activation has been built in MCNP6.1. Simple analytical calculations were also done to validate the full scale MCNP6.1 model. It has been shown that in accordance with our expectation, only the $^{40}$Ar activation could have a considerable effect in terms of radiation background. However, both the simulation and the calculation agree that either the prompt gamma intensity coming from the $^{40}$Ar neutron capture or the produced $^{41}$Ar activity is still negligible.

Speaker: Eszter Dian (HAS Centre for Energy Research)

Slides Dian_ARIA17.pdf

10:50 Discussion on the low activation design method for the accelerator facility by low activation concrete and radiation shielding flexible material

Radiation shielding is one of the important issue for accelerator facilities and nuclear power plants. It is also widely known that the radiation shielding induced the activation to the shielding materials. So, the activation is important to discuss. Especially concrete is widely used as the shielding material in the facilities because of its flexibility and inexpensively supplement, and the activation of concrete is one of the big problem because of the quantity. Low activation concrete is one of the solution for the above problem and it is suitable to construct those facilities by low activation concrete, as well as to use it as shielding material. Several types of performance, beside of low activation, were required for the concrete, such as structural property, physical stress, workability and so on. So, various types of low activation concrete were developed for different performance. In this paper, the relationship between low activation performance and several physical properties are discussed for the developed 27 types low activation concrete. In addition, the other solution for the reduction of activation is to use attached materials with neutron absorption material. Radiation shielding flexible material can contain large quantity of that material with flexibility and are introduced in this paper.

Speaker: Dr Ken-ichi Kimura (Fujita Corporation)

11:10 Development of Low-Activation Concrete for Medical Accelerators

All IBA medical accelerators make use of proton beams with energy ranging from a few MeV (medical isotopes production) up to 230 MeV (proton therapy). A common drawback is the generation of important fluxes of secondary neutrons with energies ranging from thermal energy up to the maximal proton energy. The neutron-induced long-lived isotopes produced inside the shielding concrete are responsible for the production of low-level nuclear wastes at the facility end-of-life. The handling and storage of these nuclear wastes represents today a major part of the decommissioning costs of an accelerator facility. As they are potentially concerned by this problem of concrete activation, IBA has developed new formulations for low-activation concrete. Thanks to a careful selection of the aggregates and cements, it is possible to reduce by a significant factor the elements responsible for long-lived isotope production. With this low-activation concrete, the production of low-level nuclear wastes in Proton Therapy systems is completely eliminated. The content of Europium, Cobalt and Cesium in the concrete has been determined both by neutron activation analyses and ICP-MS analyses. Based on those results, the production of nuclear waste is estimated using MCNPX for various accelerators using realistic usage scenarios.

Speaker: Dr Frédéric Stichelbaut (Ion Beam Applications)

10:00 → 10:30 Coffee Break

11:30 → 12:10 Commissioning & Operations

Convener: Mrs Irina Popova (ORNL)

11:30 Air activation studies from dark current emitted at Super Conducting Radio Frequency Cavities

Uncontained radiation showers and stray radiation at particle accelerators interact with the air volume surrounding the beam-line, leading to the generation of a broad variety of radio-isotopes, some of which have sufficiently long half-lives to either potentially reach the public after the release of air to the atmosphere or to be present in substantial amounts in the accelerator building after a delayed access to the facility following beam shut-off. High-energy lepton machines and light sources are no exception to this due to spallation and photonuclear reactions from the energetic electromagnetic cascades at beam-loss points such as collimators and dumps. Commonly accepted mitigations for this include local shielding, air ventilation controls and associated monitoring instrumentation. A less known source of air activation is dark current from the superconducting cavities of high-power accelerator such as future LCLS-II Hard X-Ray source, which includes a 4.5 GeV/250 kW superconducting electron linac. This paper shows recent simulations of dark current performed with FLUKA and Track3P, which suggest that this typically-neglected term for air activation could in some cases be comparable to electron beam losses at warm sections. Those areas would then need controls, although their implementation could be more challenging than usual. Future measurements of field emission and resulting air activation will investigate this further.

Speaker: Dr Mario Santana Leitner (SLAC National Accelerator Laboratory)

Slides Air-Cryomodule_-_Santana.pptx

11:50 Radiation challenges of primary cooling return water at the ESS

At ESS it is necessary to operate water loops for the thermal moderators and for the cooling of the beryllium- and the steel reflectors. The water in each of these components is exposed to a very high level of radiation. This cause the water and impurities therein to be activated and in this work the measures for safe handling of the return water are investigated. Immediately after exiting the target monolith 16 N ( 16 O(n,p) 16 N) with a 7s half-life is the most challenging radioisotope, due the combination of it's high abundance and hard gammas (up to 7 MeV). To reduce the shielding requirements downstream the water loop, delay tanks are foreseen and results are presented showing the implications on the radiation environment depending on the choice of location and size of these tanks. Before returned to target monolith about 10% of the water is led to ion exchangers, where long lived radioisotopes, such as 7 Be build up. These components are located in a room where regular maintenance is expected and results are shown targeted to define the shielding measures which must be implemented for safe handling. The methodology used to derive the results include MCNPX and CINDER'90 and will detailed in the presentation

Speaker: Esben Klinkby (DTU)

Slides returnWater_EsbenKlinkby.pdf

12:10 → 12:30 Radioisotopes applications

Convener: Dr Riccardo Bevilacqua (European Spallation Source ERIC)

12:10 Comparison of the 99Mo/99mTc production methods based on electron LINAC and 14 MeV neutron beams: Monte Carlo predictions and experimental results

99mTc (T1/2 = 6.0067(10) h), an isomer of 99Tc emitting -ray with energy E=140 keV, is among the most widely used radionuclides for diagnosis in nuclear medicine (NM). In this context, Europe is the second largest consumer of 99mTc, accounting for more than 20% of the global market. A severe supply crisis of 99Mo production arose in 2008-2009, due to the aging of nuclear reactors (presently the main providers of 99mTc), highlighting the fragility of the current production chain for this important medical radionuclide. Since then, a worldwide interest in investigating alternative methods to produce 99mTc for short, medium and long term period has been clearly manifested. Among the most promising accelerator driven techniques, a particular interest has been recently focused, respectively, on the 99Mo photoproduction method by means of high energy electron beams and the (n,2n) reaction based one with 14 MeV neutron beams (both using enriched 100Mo targets). These two alternative methods are analyzed and compared in the presented work: Monte Carlo predictions (based on FLUKA code) of the 99Mo activity achievable on optimized targets have been obtained for several experimental configurations and reasonable duty cycles. Moreover, the comparison of the predicted 99Mo activities with the respective experimental values obtained irradiating natural Molybdenum samples at the 14 MeV Frascati Neutron Generator (FNG) facility of the ENEA-Frascati Research Center, and at the DAΦNE Beam Test Facility (BTF) of INFN-LNF is analysed and discussed for benchmarking purposes. In fact, all the activity measurements were carried out at a high metrological level. In addition to the nuclear analysis, some preliminary thermo-physical considerations, related to the maximum beam power deposition in the target, to assess a reliable operative configuration and define a realistic 99Mo production cycle are also introduced and compared for both cases.

Speaker: Dr Lina Quintieri (ENEA Centro Ricerche della Casaccia)

12:30 → 14:00 Lunch break

14:00 → 16:00 Visit of the ESS construction site

16:00 → 16:30 Coffee Break

16:30 → 17:30 Waste management: Methods

Convener: Dr Matteo Magistris (CERN)

16:30 Radiological characterization of very-low-level radioactive waste at CERN

The operation of high-energy particle accelerators leads to the unavoidable production of radioactive waste, which must be radiologically characterized to ensure appropriate disposal in the final repositories. This task comprises the establishment of the required list of present radionuclides and a quantitative estimate of their activity. We hereby provide an overview of the methods adopted at CERN to characterize over 1’200 m3 of very-low-level radioactive waste, including the following three families of waste: metallic items from accelerator components, magnets activated in proton machines and cables. For each of these three families of waste we established the list of produced radionuclides by performing extensive calculations with the analytical code ActiWiz [1] over thousands of possible activation scenarios, and defined a set of expected activity ratios (“scaling factors”). The activities of gamma emitters inside each waste package were evaluated with systematic in-situ gamma-spectrometry (metallic items and cables) or with ambient dose equivalent rate measurements and transfer functions (magnets). Scaling factors were applied for the evaluation of the activities of difficult-to-measure radionuclides. In particular measured scaling factors – obtained via radiochemical analysis and gamma-spectrometry performed over hundreds of samples – were compared to the analytical predictions to provide a solid benchmark of the characterization method. These methods were approved by the French National Radioactive Waste Management Agency (ANDRA) and can in principle be applied to radioactive waste from other particle accelerators with very low levels of contamination. [1] H Vincke and C. Theis, “Actiwiz - Optimizing your nuclide inventory at proton accelerators with a computer code,” in ICRS12 conference, 2012.

Speaker: Dr Matteo Magistris (CERN)

Slides A1_Magistris_ARIA_2017.pptx

16:50 Calculations vs. measurements for SNS spent structures

Each spent Spallation Neutron Source (SNS) structure that leaves the SNS site requires supporting documentation with radionuclide inventory and dose rate prediction for the time of the transportation. Analyses are performed, assuming realistic irradiation history and decay case to ensure that the container/package, housing the structure, is compliant with the waste management regulations. For validating neutronics analyses, measurements of dose rates from the spent target vessel # 13 and proton beam window # 5 were performed. Neutronics analyses were performed to calculate residual dose rates from both structures for the time of measurements. Overall the calculated dose rates for the spent target vessel are in a good agreement with the measured dose rates – within 25% besides a few locations, where the dose rates are overestimated by 50%. Proton beam window dose rates are in evaluation process.

Speaker: Mrs Irina Popova (ORNL)

Slides aria_irt.ppt

17:10 Analysis of Residual Activity at the FRIB Linear Accelerator

The Facility for Rare Isotope Beams (FRIB) is an accelerator facility being established at Michigan State University (MSU). The facility will utilize a broad range of primary ion beams from 16-O to 238-U with a beam power of up to 400 kW and energy of 200 MeV/nucleon for 238-U in its baseline configuration to produce rare isotopes. A possible facility upgrade will include an increase of the beam energy up to 400 MeV/nucleon for 238-U and addition of new light ion beams down to 3-He and protons for ISOL operations. This work presents an analysis of residual activity at the FRIB linear accelerator. In addition to normal beam losses resulting in residual activation of air, services and beam elements, there are several beam devices where localized beam losses are in order of hundreds of Watt. An impact of the beam losses on the local shielding, environment, operation and disposal of activated components was evaluated. This material is based on work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. Michigan State University is designing and establishing FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

Speaker: Dr Mikhail Kostin (Facility for Rare Isotope Beams)

Slides A3_Activities_at_FRIB_Linac_-_Mikhail_Kostin.pdf

17:30 → 18:30 Waste management: Clearance

Convener: Dr James Liu (Stanford Linear Accelerator Center)

17:30 Activation Levels, Handling, Storage, and Transport of Activated Components in the Target Hall at FRIB

The Facility for Rare Isotope Beams (FRIB) project is under construction at Michigan State University. 400 kW beam operations with heavy ions ranging from oxygen to uranium will create a high radiation environment for many components, particularly for the beam line elements located in the Target Hall, where approximately 100 kW of beam power are lost in the target and another 300 kW are dissipated in the beam dump. Detailed studies of the component activation, their remote handling, as well as storage and transport, have been performed to ensure safe operation levels in this environment. Levels of activation are calculated for the beam line components within the FRIB Target Hall. During the beam-off periods, the most activated components, such as target module, beam dump, and magnets, need to be safely handled, stored for cooling, and eventually disposed in a safe manner. Various techniques and approaches of dealing with highly activated elements are presented and discussed. This material is based on work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

Speaker: Dr Mikhail Kostin (Facility for Rare Isotope Beams)

Slides A4_Georgobiani_ARIA17.pdf

17:50 Lead activation and clearance measurement protocol in Accelerator Facilities

Clearance protocols to recycle common metals such as aluminum and iron from accelerator facilities were developed at SLAC and incorporated into the U.S. DOE Standard DOE-STD-6004-2016 “Clearance and Release of Personal Property from Accelerator Facilities”. The technical basis includes key concepts such as proxy radioisotopes and measurement protocols with sufficient detection capabilities to meet the release criterion of indistinguishable from background (IFB) that is lower than the ANSI N13.12-2013 volume screening levels. However, for clearance of lead (a common shielding material in accelerators) with potential activation, FLUKA calculations show that there are no proxy radionuclides (radionuclides emitting high energy gamma rays that are easy to be measured with common survey instruments). Instead Tl-204 (a pure beta emitter with a screening level of 1 Bq/g) is the most likely radionuclide to remain in lead after decay time of months. The sensitivity values (cpm per Bq/g) of GM probes for the near-contact measurement of Tl-204 in a lead brick or sheet were calculated with FLUKA. The associated detection limit was estimated and compared with ANSI screening level for Tl-204. It was found that a large-area 50-cm2 GM probe is needed to meet the detection requirement with reasonable margin.

Speaker: Dr James Liu (SLAC National Accelerator Laboratory)

Slides A5_J_Liu_SLAC_lead_clearance_2017ARIA.ppt

18:10 Evaluation of induced activity and assessment of in-situ clearance procedures for MedAustron ion therapy accelerator components

MedAustron is a synchrotron based ion therapy and research center in Wiener Neustadt, Austria. The facility provides protons up to 250 MeV kinetic energy and carbon ions up to 400 MeV/n for clinical use. Furthermore protons up to 800 MeV will be available in a room dedicated to non-clinical research.
When operating the accelerator components and adjacent material become radioactive over time due to inevitable beam losses and dumps. Therefore samples of commonly used materials were positioned at known particle loss points to evaluate induced activity. The samples were analyzed with gamma spectroscopy and the results compared to predicted nuclide vectors weighted by the Austrian clearance limits. The nuclide vectors were obtained from simulations made with the ActiWiz software which utilizes a large amount of generic FLUKA Monte Carlo simulations. An assessment of feasible in-situ methods for clearance of (potential) radioactive materials on short time frames was done combining ActiWiz simulations and mathematical efficiency calculations to account for geometry effects.
This combination proved as a viable method for time sensitive clearance by mobile LaBr3(Ce) gamma spectrometer, or in rarer cases, by dose rate alone.

Speaker: Mr Christoph Weixelbaumer (EBG MedAustron GmbH)

Slides A6_ARIA17_CWEIXELBAUMER.pptx

20:00 → 22:00 Social diner

Wednesday, 24 May

09:00 → 10:00 Decommissioning

Convener: Dr Daniela Kiselev (Paul Scherrer Institut)

09:00 Present status of accelerator decommissioning project in Japan

In Japan, the clearance system which contains (1) the clearance level of radioactive substances for release to the environment and (2) the control procedures of the nuclear regulation authority (NRA), has been introduced in the radioisotope handling facilities and accelerator facilities. In this regulation, the definition and the handling rules for activated materials were stated. Several related topics of Japanese regulation and some examples of accelerator decommissioning are introduced. Especially, about 1000 small accelerators are in hospitals. Therefore, energy limit and zoning were adopted for electron accelerator and cyclotron, as followings. Energy limit :(1) Particle accelerators lower than 2.5 MeV/nucleon (except for neutron generators), (2) Electron accelerators for medical use at 6MeV or less. Zoning: (1) Outside the self shield of cyclotron for PET isotope production, (2) Electron accelerators for medical use at 10 MeV or less (except for target and collimators), (3) Electron accelerators for medical use of 15 MeV or less (except for target, collimators and shielding materials) In the case of PET cyclotron facilities, the wall, floor, ceiling and surrounding materials might be activated by secondary neutrons during operation. Typical neutron flux in a vault of a PET cyclotron is 105 to 106 cm-2s-1 during the production of 18F from 18O. Therefore, total production amounts of 18F become good indicators of neutron fluence. Neutron fluence of 10 years operation in a typical hospital is estimated to be 1012 to 1013 cm-2. Specific activity of 60Co and 152Eu in surface concrete become almost same as the clearance levels. Two additional data should be obtained in each facility, in order to confirm the induced activity. (1)Radioactivity of several materials sampled in the accelerator room should be measured by using a Ge-detector. (2) Induced activity of several typical materials including concrete is estimated, after obtaining the data concerning the operational history, the elemental compositions of each material, spatial distribution of neutrons under typical operation condition. Both data sets are useful for the decommissioning procedure. Concrete will become major radioactive waste in the PET cyclotron facilities. Therefore, it is also important to reduce the neutron activation by effective neutron shielding of the target. Adoption of the clearance system hospitals is currently time consuming and too costly for small facilities. Hospitals generally have no storage areas suitable for accumulation of decommissioning materials and often must maintain continuity of patient treatments. In such circumstances, the NRA accepts that hospitals adopt a decommissioning procedure without using the clearance system. In the case of activation of accelerators, induced nuclides are generally gamma-emitters. Therefore, this measurement is based on the use of scintillation survey meters to segregate activated materials from non-activated materials. This procedure was effective to check for the non-activated levels based on the detection limits. Now, we would like to construct the acceptable procedure for accelerator decommissioning soon. Kazuyoshi Masumoto, High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaraki 305-0801, JAPAN

Speaker: Prof. Kazuyoshi Masumoto (High Energy Accelerator Research Organization)

Slides 1_masumoto-ARIA0522.pptx

09:20 Evaluation activity induced in various components of PET-cyclotron

In case of the decommissioning of cyclotron facility, it is important to evaluate the induced activity of various components of cyclotron. In this work, two types of cyclotron such as proton acceleration using a deflector and H- acceleration using a carbon stripper foil for beam extraction to target port were selected. The former type was Cyclone10/5 of IBA and the latter type was BC-1710 of JSW. Sample was obtained from yoke, sector magnet, coil, vacuum chamber, pedestal and diffusion pomp by drilling, core boring and cutting. Radioactivity was measured with Ge-detector. (1) Cyclone 10/5 Major nuclides were 60Co and 54Mn in yoke, 60Co in coil, vacuum chamber, pedestal and diffusion pomp. In case of the sector magnet, 65Zn from surface cooper plating was also detected. Activity of 60Co of inside surface of the yoke was high and gradually decreased with depth. But activity of 54Mn induced by the (n,p) reaction from 54Fe was decreased more rapidly with depth. The ratiso of observed activity to clearance level (ΣD/C) of vacuum chamber, pedestal and major part of coil were lower than 1. The ratios (ΣD/C) of sector magnet, diffusion pomp and inside of yoke were higher than 1. (2) BC-1710 of JSW Observed major nuclides were almost same as Cyclone10/5. As sampling was performed three month after shutdown, short-lived nuclides such as 59Fe and 58Co were also observed. Induced activity of 60Co and 54Mn of yoke was high near the deflector (inside part) and the target (outside part). The attenuation curves of 60Co activity in yoke obtained from 10 sampling positions were almost same. The ratios (ΣD/C) obtained from most of the components were higher than 1. In case of yoke, we have to wait for 20 years to reach the clearance level. In order to obtain the activity in various components, the use of survey meter is very convenient. Therefore it is very important to obtain the relation between dose and activity. Monte Carlo calculation is also important to evaluate the neutron transport and activation inside the components of cyclotron. Takayuki Nakabayashi, Toshiyuki Yagishita, Hiroyuki Sasaki, Kazuhiro Matsumura, Yoshiyuki Yamaya Japan Environment Research Co., Ltd., 6-24-1 Nishi-shinjuku, Shinjuku-ku, Tokyo 160-0023, JAPAN Hiroshi Matsumura, Akihiro Toyoda, Kazuyoshi Masumoto, High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaraki 305-0801, JAPAN

Speaker: Mr Takayuki Nakabayashi (Japan Environmental Research Co., Ltd.)

Slides 2_aria2017-Akihiro-Toyoda.pptx

09:40 In-situ determination of residual specific activity in activated concrete walls of a PET-cyclotron room

A 12-MeV cyclotron used for production of radiopharmaceuticals for positron-emission tomography (PET) at the Medical and Pharmacological Research Center Foundation in Hakui, Ishikawa, Japan was decommissioned in March 2015. The decommissioning work began immediately, and the entire cyclotron body and its accessories were removed from the cyclotron room. Currently, a method for measuring the specific activity distribution in all concrete walls of the cyclotron room is required in order to identify the contaminated part. Therefore, in this study, an in-situ specific-activity determination method was developed.

Speaker: Dr Hiroshi Matsumura (KEK)

Slides 3_Matsumura.pptx

10:00 → 10:30 Coffee Break

10:30 → 11:30 Environment

Convener: Daniela Ene (European Spallation Source ERIC)

10:30 Assessment of environmental consequences of the normal operations of the ESS facility

A radiological assessment has been produced to demonstrate that during normal operations the European Spallation Source (ESS) facility will comply with the dose constraints imposed by the Swedish Authority. The evaluation of exposures to impacted environmental media considers three main pathways: i) airborne releases of radionuclides through ventilation, ii) liquid discharges of radionuclides to the sewage system and downstream surface water (rivers and sea), iii) migration of radionuclides with groundwater following activation of the surrounding soil. The impact assessment has two main phases: i) estimation of the source term (ST), by means of calculation of radioactivity (Monte Carlo radiation transport simulations coupled with activation calculations by means CINDER’90 code) that can be released annually and taking into account the design parameters of the abatement systems, e.g. ventilation system (HVAC), and ii) applying dispersion and radionuclide transport models to calculate concentrations in the environment and dose models to calculate doses to reference groups of the population around the site. In case of releases to the atmosphere, the total annual dose obtained is below 1 µSv/year and is dominated by N-13, C-11, Ar-41, O-15 and I-125. The results of modelling of migration of contaminants with the groundwater show that doses will be formed practically 100% by tritium, whose concentrations in well water are approximately one order of magnitude below the admissible level of 100 Bq/L. The present work report only partial results as the release rates for several facility components are still under investigation. It was concluded from this assessment that for the known release rates the sum of the doses resulting from the exposure of any member of the public to ionizing radiation are very small.

Speaker: Daniela Ene (European Spallation Source ERIC)

Slides 4_dene_aria17_m.pdf

10:50 Leakage of radioactive materials from particle accelerator facilities by non-radiation disasters like fire and flooding and its environmental impacts

The leakage of radioactive materials generated at particle accelerator facilities is one of the important issues in the view of radiation safety. In this study, fire and flooding at particle accelerator facilities were considered as the non-radiation disasters which result to the leakage or spread-out of radioactive materials. To analyze the expected effects at each disaster, the case study on fired and flooded particle accelerator facilities was done with the property investigation of interesting materials generated in the accelerator tunnel and the activity estimation. Five major materials in the tunnel were investigated: dust, insulators, concrete, metals and paints. The activation level on the concerned materials were calculated using several Monte Carlo codes (MCNPX 2.7+SP-FISPACT 2007, FLUKA 2011.4c and PHITS 2.64+DCHAIN-SP 2001). The impact weight was estimated for the different beam particles (electron, proton, carbon and uranium) and the different beam energies (100, 430, 600 and 1000 MeV/nucleon). With the consideration of the leakage path of radioactive materials due to fire and flooding and the activation level of selected materials, the impacts to the environment were evaluated. In the case of flooding, dust, concrete and metal were found as a considerable object. In the case of fire event, dust, insulator and paint should be taken care for. As expected, the influence of normal fire and flooding at electron accelerator facilities would be relatively low for both cases.

Speaker: Ms Arim Lee (Pohang Accelerator Laboratory)

Slides 5_ARIA17_FloodFire_ALee_Final.pptx

11:10 Activation assessment of the soil around the ESS accelerator tunnel

Activation of the soil surrounding the ESS accelerator tunnel calculated by the MARS15 code is presented. A detailed composition of the soil, that comprises about 30 different chemical elements, is taken into account. Spatial distributions of the produced activity are provided in both transverse and longitudinal direction. A realistic irradiation profile for the entire planned lifetime of the facility is used. The nuclear transmutation and decay of the produced radionuclides is calculated with the DeTra code which is a built-in tool for the MARS15 code. Evaluated nuclear data for some of the soil components—Sr, Ce, Nd, Dy—at present can be found only in the ENDF/B-VII library. Therefore, radionuclide production by low-energy neutrons is calculated using the most recent data libraries, mostly ENDF/B-VII, included in the MCNP6 package.

Speaker: Igor Rakhno (Fermi National Accelerator Laboratory)

Slides irakhno_aria17.pptx

11:30 → 12:30 Summary, future actions, ARIA 2017

11:30 Summary of ARIA & Conclusion

Speaker: Daniela Ene (European Spallation Source ERIC)

12:00 Remarks and future actions for ARIA 2017

Speaker: Daniela Ene (European Spallation Source ERIC)

12:30 → 14:00 Lunch Break