Remote Handling in the Accelerator Systems of DONES Arranz, Fernando; Micciche, Gioacchino; Coloma, Sofia ...
IEEE transactions on plasma science,
2020-June, 2020-6-00, Volume:
48, Issue:
6
Journal Article
Peer reviewed
DEMOstration (DEMO)-oriented neutron source (DONES) will be an installation for fusion material testing, with a neutron flux of 14 MeV by Li(d, xn) nuclear reactions thanks to a deuteron beam ...colliding on a liquid Li flow. The expected neutron flux is in the order of <inline-formula> <tex-math notation="LaTeX">10^{18}\,\,\text{m}^{-2}\cdot \text{s}^{-1} </tex-math></inline-formula> to get irradiation conditions comparable to those on the first wall of a fusion reactor. The test systems will include specimens to be irradiated and later on tested in order to quantify the impact of nuclear damage on mechanical and physical properties. Such experiments will support the future design of DEMO (DEMO power plant based on a fusion reactor). The accelerator systems providing high energy deuterons will receive neutrons as well as gamma rays once the operation of the installation starts hence requiring remote handling (RH) for maintenance on certain components. Particularly a beam dump used for the commissioning phase and the scrapers protecting some high energy beam transport (HEBT) magnets, should be maintained and occasionally replaced by means of RH. The system devised for the RH operations is described together with the requirements imposed on the HEBT designers and Plant Systems designers such that the RH equipment can perform the maintenance in a reduced downtime.
Glucocorticoid resistance is a major driver of therapeutic failure in T cell acute lymphoblastic leukemia (T-ALL). Here, we identify the AKT1 kinase as a major negative regulator of the NR3C1 ...glucocorticoid receptor protein activity driving glucocorticoid resistance in T-ALL. Mechanistically, AKT1 impairs glucocorticoid-induced gene expression by direct phosphorylation of NR3C1 at position S134 and blocking glucocorticoid-induced NR3C1 translocation to the nucleus. Moreover, we demonstrate that loss of PTEN and consequent AKT1 activation can effectively block glucocorticoid-induced apoptosis and induce resistance to glucocorticoid therapy. Conversely, pharmacologic inhibition of AKT with MK2206 effectively restores glucocorticoid-induced NR3C1 translocation to the nucleus, increases the response of T-ALL cells to glucocorticoid therapy, and effectively reverses glucocorticoid resistance in vitro and in vivo.
•AKT1 directly phosphorylates the NR3C1 glucocorticoid receptor protein•AKT-mediated S134 phosphorylation blocks nuclear translocation of NR3C1•PTEN loss and AKT1 activation induce glucocorticoid resistance in T-ALL•Pharmacologic inhibition of AKT1 reverses glucocorticoid resistance in T-ALL
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•Integration of all necessary diagnostics devices for beam characterization to allow an adequate monitoring of the beam dynamics requirements of IFMIF-DONES.•Fast Isolation Valve integrated to ...prevent water ingress in the Target and avoid exothermic reaction with the Lithium curtain.•Large Replaceable Units approach that allow fast replacement of modules reducing the DONES facility downtime during maintenance.•Remote Handling compatible design of accelerator devices with features to provide quick maintenance operations.
The High Energy Beam Transport (HEBT) line components maintenance are to be conducted during twice yearly shutdown “beam off” periods, one 3-day shutdown and the main “beam off” shutdown period (annual preventive maintenance), which includes the necessary cooling and warming time, all totalling 20 days. Due to the radiation doses calculated and its subsequent radiation zone classification, technically challenging maintenance activities will need to be performed in the Accelerator Systems (AS) and particularly in the HEBT section located inside Target Interface Room (TIR). Thus, all HEBT components inside TIR must be designed to be maintained and replaced by Remote Handling (RH). In order to fulfil the RH requirements, a modularity approach intends to divide HEBT line section into independent large replacement units (LRUs), with localized interfaces. Splitting this section in three modules allows, first, the identification of faulty components more easily and secondly, reduces time needed for their replacement. In addition, the design of these modules has been performed to comply with beam dynamics, vacuum, building, RAMI and positioning requirements established for this section of the HEBT. As a result of the work done, the conclusions concerning the whole design process are summarized at the end of the paper.
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IFMIF-DONES aims at providing high-energy deuterons to produce a neutron flux to test materials. The accelerator stops the pulsed beam at a low duty cycle in the Beam Dump, which is a relevant ...component of the High Energy Beam Transport line. The cartridge of the Beam Dump absorbs a beam of charged particles during DONES accelerator commissioning and start-up phases after a shutdown. The cartridge is contained for security reasons in a shielding given its high activation, which remains for a long time. Deterioration of this component is due to heating cycles, radiation and corrosion caused by the cartridge cooling water. Thereby, Beam Dump has been classified as 3rd class Remote Handling component. It means that there is no scheduled maintenance for this component, but Remote Handling operations are required in case of failure. Remote equipment is mandatory when the Beam Dump shielding is open due to the high radiation levels. This work presents the maintenance operations to replace the Beam Dump cartridge. It includes the sequence and description of the procedures, equipment and tools necessary to meet the project requirements.
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IFMIF-DONES (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is a fusion materials testing facility that is currently being designed under the framework of a work ...package of the EUROfusion Consortium. It will use a 125mA at 40MeV deuteron beam to generate a high neutron flux through Li(d,xn) stripping nuclear reactions in a liquid lithium target. The High Energy Beam Transport line (HEBT), the most upstream system of the IFMIF-DONES accelerator, is responsible for the guidance and shaping of the beam towards the target. Additionally, during commissioning periods, the HEBT is also responsible for diverting the beam, through the Beam Dump Transport Line, to the Beam Dump for testing purposes. The HEBT is spread along different rooms and zones: the Accelerator Vault, the Radiation Interface Zone (RIZ), and Target Interface Room (TIR). The engineering design of the HEBT components situated within the TIR and RIZ has been updated to satisfy new requirements, with a focus on ensuring the protecting of the Fast Isolation Valve (FIV) from the backscattered radiation from the target. These modifications include relocating the FIV from the TIR to the RIZ, adjusting the building layout to accommodate the new FIV module, configuring an enclosure cabinet for the RIZ, and adding local shielding to extend the lifetime of the FIV seal actuators. This work describes the current status of these TIR and RIZ engineering design, including radioprotection, commissioning and maintenance plan, beam diagnostics devices, beam dynamics and new remote handling approaches, as well as the layout and integration of the required components along the beamline. The TIR and RIZ are critical areas for IFMIF-DONES, and their design and operation must be compliant with functional, reliability and safety requirements. The updated design addresses potential issues and enhances the facility’s overall functionality.
•Collimator redesigned with new coolant fluid for the near TS safety measures.•TIR layout shift to two LRU frees space for new elements.•TIR-RIZ wall thickness reduced by one meter for space.•Enclosure cabinet in RIZ stores argon atmosphere for the FIV.•FIV lifespan doubled by implementing local shielding strategies.
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•Functional and radiological requirements for HEBT Beam Dump Shielding are described.•Radiological analysis of Beam Dump Shielding is detailed for its two operational conditions.•Materials and ...dimensions for the Beam Dump Shielding conceptual design are explained.•Two Beam Dump Shielding configuration approaches have been studied and compared.•Benefits and drawbacks for each configuration proposed have been identified.
IFMIF-DONES (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is currently being developed in the frame of the EUROfusion Early Neutron Source work package (WPENS). It will be an installation for fusion material testing, that will generate a flux of neutrons of 1018 m−2s−1 with a broad peak at 14 MeV by Li(d,xn) nuclear reactions thanks to a deuteron beam colliding on a liquid Li flow.
The accelerator system is in charge of providing such high energy deuterons in order to produce the neutron flux expected. The objective of the Beam Dump, part of the High Energy Beam Transport Line (HEBT), is to stop the pulsed beam at low duty cycle during DONES accelerator commissioning and start-up phases.
The present work explains the radiological design of the beam dump shielding and two different configuration approaches for the materialization of the design. The radiological design considers maintenance and operation, and it was done together with the building walls dimensioning so that the combined radiation attenuation by the local shield and the building leads to dose rates in the different rooms that satisfy the requirements. Activation of the materials in the HEBT line, originated by the leakage of neutrons through the beam dump entrance is evaluated and an ad-hoc solution is proposed for its minimization. Regarding the mechanical design, in the first configuration, the shielding is split into two halves horizontally, the upper-half requiring external lifting capabilities for its commission and maintenance. The second approach consists in a vertical splitting into two halves, which are self-moveable, avoiding the needs of external lifting capabilities for the remote handling of the shielding.
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The exocrine pancreas can undergo acinar-to-ductal metaplasia (ADM), as in the case of pancreatitis where precursor lesions of pancreatic ductal adenocarcinoma (PDAC) can arise. The NAD(+)-dependent ...protein deacetylase Sirtuin-1 (Sirt1) has been implicated in carcinogenesis with dual roles depending on its subcellular localization. In this study, we examined the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis, i.e. ADM models and established PDAC. In addition, we analyzed the expression of KIAA1967, a key mediator of Sirt1 function, along with potential Sirt1 downstream targets. Sirt1 was co-expressed with KIAA1967 in the nuclei of normal pancreatic acinar cells. In ADM, Sirt1 underwent a transient nuclear-to-cytoplasmic shuttling. Experiments where during ADM, we enforced repression of Sirt1 shuttling, inhibition of Sirt1 activity or modulation of its expression, all underscore that the temporary decrease of nuclear and increase of cytoplasmic Sirt1 stimulate ADM. Our results further underscore that important transcriptional regulators of acinar differentiation, that is, Pancreatic transcription factor-1a and β-catenin can be deacetylated by Sirt1. Inhibition of Sirt1 is effective in suppression of ADM and in reducing cell viability in established PDAC tumors. KIAA1967 expression is differentially downregulated in PDAC and impacts on the sensitivity of PDAC cells to the Sirt1/2 inhibitor Tenovin-6. In PDAC, acetylation of β-catenin is not affected, unlike p53, a well-characterized Sirt1-regulated protein in tumor cells. Our results reveal that Sirt1 is an important regulator and potential therapeutic target in pancreatic carcinogenesis.
IFMIF-DONES will be an irradiation facility based on a 40 MeV deuteron accelerator. Unavoidable beam losses along the accelerator result in deuterium interactions with the beam facing materials of ...the vacuum beam pipe, some of them leading to material activation. The initial design of the beam pipe was based on stainless steel, but an evaluation of the residual doses from the pipe showed high values after operation of the accelerator. The accelerator beam line must be periodically maintained, and excessive cooling times for reaching acceptable dose levels may result in poorer availability of the facility. A deeper study of the High Energy Beam Transport line (HEBT) showed that a direct reaction between deuterons and iron in steel resulted in the production of Co-56, with a half-life of 77 days. This radioisotope is the main source of the radiation and makes it impractical to wait for a proper attenuation of the radiation field. A redesign of beam line elements has been performed to avoid the presence of stainless steel as a beam facing material and to replace it with aluminum where possible, resulting in faster decay of residual doses. This work contains a summary of the nuclear analysis performed for the computation of residual doses with stainless steel beam pipe, stressing the uncertainties of the calculations, based on the limited availability of nuclear data for the relevant nuclear reaction Fe56 (d,2n). The proposed replacement of element materials is also described, and an updated nuclear analysis shows the reduction of residual radiation, and its impact on possible maintenance operations.
•This document reflects the efforts made within the IFMIF-DONES project towards a safe radiological materials design, following the ALARA principles.•The authors have made nuclear analyses to support the conclusions and change of design.•Some flaws in existing nuclear data have been discovered, relayed to the responsible people in the EU and IAEA framework to correct the deficiencies.
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One of the challenges in Microbial Fuel Cell (MFC) technology is the improvement of the power output and the lowering of the cost required to scale up the system to reach usable energy levels for ...real life applications. This can be achieved by stacking multiple MFC units in modules and using cost effective ceramic as a membrane/chassis for the reactor architecture. The main aim of this work is to increase the power output efficiency of the ceramic based MFCs by compacting the design and exploring the ceramic support as the building block for small scale modular multi-unit systems. The comparison of the power output showed that the small reactors outperform the large MFCs by improving the power density reaching up to 20.4 W/m
(mean value) and 25.7 W/m
(maximum). This can be related to the increased surface-area-to-volume ratio of the ceramic membrane and a decreased electrode distance. The power performance was also influenced by the type and thickness of the ceramic separator as well as the total surface area of the anode electrode. The study showed that the larger anode electrode area gives an increased power output. The miniaturized design implemented in 560-units MFC stack showed an output up to 245 mW of power and increased power density. Such strategy would allow to utilize the energy locked in urine more efficiently, making MFCs more applicable in industrial and municipal wastewater treatment facilities, and scale-up-ready for real world implementation.
IFMIF-DONES is a facility under construction in Granada, whose main goal is the validation and characterization of materials under a fusion prototypic irradiation field. This field is created by the ...interaction of a high energy intense continuous deuteron beam and a flowing liquid lithium target. The requirements imposed on the beam at the interaction point are a complex trade-off among the scientific experimental needs for the materials irradiation defined at the top-level requirements (20 dpa in a volume of 0.3 dm3 and 50 dpa in 0.1 dm3), and the technical constraints of several systems such as the Accelerator Systems, the Lithium Systems, and the Test Systems. Recent simulations with the initial definition of beam-on-target requirements showed the necessity of redefining them in order to fulfill the irradiation needs. This contribution will address the main challenges to gather the inputs for the definition and reassessment of the beam-on-target requirements. A comparison detailing the main changes compared to the previous ones will be given, together with a short overview of the studies ongoing by different systems to analyze the impact of each beam-on-target requirements on the performance of the whole facility.
•Fusion materials irradiation.•Deuteron accelerator.•High current accelerator.•Beam delivery system.•Beam on-target.
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