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The current integration state of ITER Equatorial Port #11 (EP#11) is described. This port is the first plasma port and thus the integration phase is close to the final stage. The new modular design of neutron shielding is implemented in the Diagnostic shielding modules’ (DSM) construction to achieve the maximum shielding efficiency within the weight restrictions and keeping fully operable the tenant diagnostics systems. The same approach was applied to Interspace structure frame design to allow the safe hand-on maintenance near the highly activated components. The current iteration of the engineering calculations, including the neutron transport and shutdown dose rate (SDDR), thermohydraulics, electromagnetics, seismic, and structure integrity calculations, showed that the current design of EP#11 satisfy all ITER requirements. The special metalworking, welding, and various other technologies are tested during the process of preparation for the manufacturing of ITER EP#11. Production technologies of the full-size DSM mock-up and various elements of its infrastructure were tested. The multizoned clean area assembly hall for the final assembly is close to getting completed and the testing of vacuum items has to be sent to ITER.

This article reports the results of the assessment performed on the ITER Divertor Thomson Scattering (DTS). It is designed to provide an instrument capable of measuring the electron temperature and the related density profiles in the outer divertor plasma, relying on Thomson scattering method. The DTS main components are front rack, back rack, neutron shielding and diagnostic mirrors. Current DTS design has been modified compared to the one described in the previous article dedicated to this object. The most significant changes are: • Upper neutron shielding has been removed. It is now not connected directly with the DTS system. It helped to reduce total weight of the construction; • Dielectric insertions were added in order to reduce influence of the ponderomotive forces on construction strength; • DTS supports were redesigned. Connections of the DTS with radial rails on which the construction is mounted on the sides were explored. Corresponding contact problem was solved and the structure integrity in this area was assessed. Mirrors made of SiC material are the DTS diagnostic elements. They are installed into front and back diagnostic racks. Other elements of the DTS are made of 316L(N)-IG steel. The contact pads on the radial rails are made of 660 steel. The whole Divertor Thomson Scattering system has to withstand all the loads (thermal, mechanical, electromagnetic and seismic) acting on the in-vessel region in which it is located without compromising its integrity. Its design layout is being modified and optimized according to the outcome of the structural assessment. Every step of the design update brings the construction closer to satisfying all of the criterions of structural integrity. This paper describes some important steps that really help moving forward to the DTS implementation.

Based on the fusion energy problem, this article shows results of the studies, which have been done to justify the current Upper port plug (UPP) of ITER upper ports №02 and №08 design. As for the previous UPP design, some structure elements were absent. ITER port plugs are supposed to be working under various types of loads. Particularly, these loads are thermal, inertial and electromagnetic (EM). Most of the ITER strength calculations are performed using finite element method (FEM). For example, UPP construction consists of many different parts, so it is necessary to consider their contact interaction. Nonlinear problem formulation has been used to obtain accurate results of the calculations. In addition, bolt pretension has been taken into account, that has not been considered in the previous version of the UPP design analysis. Firstly, results of thermo-hydraulic analysis illustrate the problem with the boron carbide (B4C) bricks during Baking mode in the UPP shielding. Secondly, load combination of seismic and EM loads show the UPP structure strength assessment. This article, in general, represents some results shown in the Structural Integrity Report and obtained during the process of the UPP design justification following RCC-MR code.

ITER (International Thermonuclear Experimental Reactor) is a nuclear fusion research and engineering project. It is supposed to be the first fusion device to test the integrated technologies, materials and operational regimes necessary for the commercial production of fusion-based electricity. Front (explored in this paper) and Back diagnostic racks are used as supporting structures of the so-called ITER Divertor Thomson Scattering (DTS) Diagnostic System that is created to measure plasma characteristics. They will be attached to the lower port walls (ITER ports are used to locate diagnostic equipment and its supporting structures) through the so-called Divertor Rails. The developed design of the Front (Diagnostic) Rack locking (e.g. Rack attachment to the rails mechanism) was analyzed in this research to be consistent with thermal stresses, electromagnetic and seismic loads taking into account some specific assembly and maintenance loads including preloading under installation. The analysis of the rack locking design's resistance to the mentioned loads should prove correspondence of the suggested common rack design with the structure integrity criterions. Construction strength under the most severe loading scenario was estimated in this research and appropriate conclusions were made. It was found out that the stress criterion was not fully satisfied, so a new rack locking design concept was proposed. Its main details are also described at the end of this article.

Lower Vertical Neutron Camera (LVNC) is a diagnostic system installed into the Diagnostic Rack of the ITER Lower Port #14. LVNC includes water cooling system, six detectors units, electrical feedthroughs and cables. Finite element model and finite volume model created with ANSYS software were used to obtain temperature and stress-strain state during Normal Operation and Baking modes.

The H-alpha diagnostic components are attached to the ITER equatorial port-plug (EPP) #11. Diagnostic system includes four mirrors, shutter unit with driven shaft and built-in mirror cleaning system (MCS). Modified finite element model created with the Ansys Maxwell software was used to obtain electromagnetic (EM) forces for the updated design of H-alpha diagnostic components during plasma disruption. This EM model contains important surrounding structural elements of the equatorial port, such as the updated DSM 02 in the equatorial port #11, which includes backfillings (surrounding structures of the H-alpha components) and trays.

The ITER Divertor Thomson Scattering system is designed to provide an instrument capable of measuring the profiles of electron temperature and relative profiles of electron density in the outer divertor plasma. Main components of construction are front rack, back rack, neutron shielding and diagnostic mirrors. The whole Divertor Thomson Scattering system has been analyzed to be consistent with thermal, mechanical, electromagnetic and seismic loads which can affect construction. All the obtained results, such as displacement and stress maps, temperature distribution and values of forces and torques in construction during plasma disruption events, can lead to some significant changes in construction design in order to improve the system.

ITER is a nuclear fusion research and engineering project. It is supposed to be the first fusion device designed for testing the integrated technologies, materials, and physical aspects necessary for development of the commercially available fusion-power plant. One of the important components of the project is optical diagnostic systems with collecting mirrors. These mirrors have to provide stability of optical systems under severe loads of different types that could possibly arise in the tokamak. The collecting mirrors of several ITER diagnostics have a large scale and should be installed into diagnostic ports. Thermal stress analysis of the mirror updated design is aimed to obtain deformation and rotation values of the mirrors’ reflecting surfaces in order to conduct ray tracing analysis and to edit mirrors alignment to provide correct functioning of the optical systems. The maximum temperature values of the Divertor Thomson Scattering collecting mirrors were estimated for the normal operation mode. The FE model of the second mirror takes into account all the force boundary conditions, basic kinematic boundary conditions and constraints. Boundary conditions taken for the simulation were applied on surfaces contacting with the diagnostic rack. Thermally stressed state was calculated and corresponding displacement and rotation distributions were obtained.

In this article the results of the strength analysis of nuclear power plant structures in case of aircraft crash impact problem are presented.Finite element analysis was performed using ABAQUS CAE system. Nonlinear material models were used, such as “Concrete damaged plasticity” and “Drucker-Prager” for concrete and elastic-plastic model for steel.For the purpose of verification of the mathematical models and engineering methods used in reinforcement concrete buildings strength analysis under different loads (static and transient temperature, structural and other loads), the following computational simulations were carried out: uniaxial compression of the cylindrical concrete specimens; reinforced concrete beams analysis under the static loads;reinforced concrete slab analysis under dynamic loads; reinforced concrete slab analysis under the missile impact. Experimental data for the aforenamed verificatory tasks was found in periodicals.

The support structure for divertor Thomson scattering equipment – the front diagnostic rack, which actually plays plugging role of the divertor port, should be designed to sustain the severe ITER conditions. Meeting the requirements of multifield analyses (which often contradict each other) results in an iterative design process. A number of design variants based on engineering analyses results were developed in 2011–2012. We study here the close to the final design of the diagnostic rack for consistency to electromagnetic, thermal and seismic loads. The specific ITER environment imposes a restricted list of materials and requires a careful design of optical elements to accommodate their thermal expansion. Special attention is focused on the mirror deformed shape under operating loading conditions and its effect on optical system performance, which is vital for all optical systems with mirrors specially designed for the ITER.

Vertical Neutron Camera (VNC) is a multichannel neutron collimator intended to characterize the fusion plasma neutron source. The VNC diagnostics (together with the 55.B1 Radial Neutron Camera) will measure the time-resolved neutron emission profiles for both DD and DT ITER plasmas, providing evaluation of the fusion power density, α-source density, neutron and α-source emissivity profiles, ion temperature profile, fusion power, total neutron flux and others parameters. The VNC is composed of two fanshaped collimating structures (lower and upper) that are located at different positions of the ITER Vacuum Vessel (VV). Structural integrity assessment of the preliminary design of the Upper Vertical Neutron Camera has been performed. The design was updated based on the analysis results and in order to meet other ITER requirements. The thermal, mechanical, electromagnetic and seismic loads and load combinations were calculated and analyzed for the updated design. This article is focused on the normal operation thermal analysis and electromagnetic analysis, as the design changes mostly affect the thermal and electromagnetic interfaces within the structure. The important results were obtained; the article shows the considerable improvement in the construction performance.

The divertor port racks used as a support structure of the divertor Thomson scattering equipment has been carefully analyzed to be consistent with electromagnetic and seismic loads. It follows from the foregoing simulations that namely these analyses demonstrate critical challenges associated with the structure design. Based on the results of the reference structure [2] a modified design of the diagnostic racks is proposed and updated simulation results are given. The results signify a significant improvement over the previous reference layout and the design will be continued towards finalization.

Acoustoelasticity approach is a method of non-destructive testing and it is based upon the theory of propagation of ultrasonic longitudinal and transverse waves of different polarization in solids. This approach is able to uniquely determine the value of the principal stress in the case of no plastic deformation. An elastoplastic material with hardening is taken and the problem of propagation of a plane acoustic wave in a homogeneous prismatic elastic-plastic body that is uniaxially prestressed in the direction perpendicular to the wave propagation direction is solved. The sound velocities for the transverse and longitudinal waves are obtained for different approximations in terms of the first and second order of smallness. A strong dependence of the velocities from the hardening factor and component of the deviatoric stress tensor was detected. The study provides a number of closed-form expressions required for solving the practical problem of technical diagnostics of structures exposing plasticity.

A divertor Thomson scattering (TS) system being developed for ITER has incorporated proven solutions from currently available TS systems. On the other hand any ITER diagnostic has to operate in a hostile environment and very restricted access geometry. Therefore the operation in an environment of intensive stray light, plasma background radiation, the necessity meet the requirement using only a 20 mm gap between divertor cassettes for plasma diagnosis as well as to measure plasma temperatures as low as 1 eV severely constrain the divertor TS diagnostic design. The challenging solutions of this novel diagnostic system which has to ensure its steady performance and also the operability and maintenance are the focus of this report. One of the most demanding parts of the in-vessel diagnostic equipment development is the design assessment using different engineering analyses. The task definition and first results of thermal, e/m and seismic analyses are provided. The process of further improving of the design involves identification of susceptible areas and multiple iterations of the design, as needed. One of the key points for all Thomson scattering diagnostics are the laser capabilities. A high-performance and high-power laser system using a steady-state and high-repetitive mode Nd:YAG laser (2J, 50–100Hz, 3ns) has been developed. The reduced laser pulse duration matched with high-speed low-noise APD detector can be very important under high background light level. For diagnostics such as Thomson scattering and Raman spectroscopy, a high-degree of discrimination against stray light at the laser wavelength is required for successful detection of wavelength-shifted light from the laser-plasma interaction region. For this case of high stray light level, a triple grating polychromator characterized by high rejection and high transmission has been designed and developed. The novel polychromator design minimizes stray light while still maintaining a relatively high transmission.