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DOE OSTI2013

Uncertainty propagation in full-core Monte Carlo depletion simulations using Serpent

The desire to accurately model the heterogeneity of the nuclear reactor environment combined with the ever more powerful computational resources have made in recent years the use of Monte Carlo method more attractive and feasible (if challenging) even for 3-D full core depletion simulation. However, in this case statistical uncertainty is combined with error propagating through the calculation from previous steps. In an effort to understand this error propagation, a numerical study was undertaken and previously reported modeling depletion of a four fuel assemblies (a 'quad'). This work extends results and analysis on a full nuclear reactor core depletion simulation where isotopics of individual fuel pins is tracked. By changing the code's initial random number seed, the data produced by a series of 19 replica runs was used to investigate the true and apparent variance in k{sub eff} and pin powers. It is hoped that this results can help to identify some common regularities in the behavior of uncertainty in several key parameters, and ultimately develop a predictive model. (authors)

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2017

Impact of grid growth on PWR spent fuel pool criticality analysis

Zircaloy based grids tend to grow with increasing fuel burnup. Grid growth increases the fuel pin pitch, which can increase fuel reactivity in the spent fuel pool. The amount of grid growth is dependent on the grid material. Zircaloy-4 grids tend to grow more than modern alloys such as Westinghouse Zirlo{sup TM} or AREVA M5{sup TM}, that have been developed, in part, to reduce irradiation growth. Grid growth has been included in the recent criticality analysis of the North Anna and Indian Point Unit 2 spent fuel pools. Grid growth is temperature dependent so the grid growth is not uniform over the axial length of the fuel. Above the active fuel is an Inconel grid which grows insignificantly. It has been conservatively assumed that the fuel pin pitch increases uniformly at all axial planes consistent with the maximum grid growth of any grid. Although this may seem overly conservative, the reactivity in the spent fuel pool for heavily burned fuel is dominated by the top few feet where the maximum grid growth occurs. At 50 GWd/MTU the grid growth is approximated as 0.47% for the Indian Point Unit 2 analysis. Assuming a uniform increase in pitch of 0.47% for 50 GWd/MTU fuel, the pool reactivity increases about 0.003 in k or about 0.6 GWd/MTU. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2019

Challenges of SLOWPOKE-2 HEU Irradiated Fuel Transportation from Canada to USA - 19123(2)

The SLOWPOKE-2 (Safe Low-Power Kritical Experiment) was designed by AECL (Atomic Energy of Canada Limited) in the late 1960's. The core consists of HEU (highly enriched uranium) fuel with an enrichment of 93%. The fuel cage typically has approximately 300 fuel pins assembled in a triangular pitch between the two plates. The fuel pins are made from uranium-aluminum alloy cladded with aluminum. The SLOWPOKE-2 reactor is rated at a nominal 20 kW. with varying neutron flux, maximum being 1 E12 n/cm{sup 2}/s. The mass of the fuel cage is 5.06 kg. The life of the core can be extended by adding layers of beryllium reflector. The transportation flask for the irradiated fuel is a Type B(U)F. The shipment classification is UN3328 Class 7. To date, 4 SLOWPOKE-2 reactors have been decommissioned. The fuel from all these reactors was transported to the U.S. The CNSC (Canadian Nuclear Safety Commission) joint Canada-United States guide for approval of Type B(U) and fissile material transportation packages (RD-364) satisfies the requirements stipulated in International Atomic energy Agency (IAEA) TS-R-1 1996 edition (revised) and is acceptable to the DOT (Department of Transportation) and NRC (Nuclear Regulatory Commission) for complying with U.S. code of federal regulations 10 CFR Part 71. The export license is issued by the CNSC. The transportation licence is issued by CNSC after approval from TC (Transport Canada) and also by DOT after approval from NRC. The final home of the HEU SLOWPOKE-2 irradiated fuel is in Savannah River Site of DOE (Department of Energy). The transportation licence requires that the Type B(U)F flask is structurally sound in case of a crash. The US DOT provides a CAC (Competent Authority Certificate) which describes the irradiated fuel specifications that can be transported in the designated flask. The U.S. DOT also requires a leak test certification in accordance with ANSI N14.5-2014 to verify a leakage rate not to exceed 1 E-7 std-cm{sup 3}/s. As most SLOWPOKE-2 facilities are not located on the existing approved routes for nuclear fuel transportation, a route survey needs to be performed and submitted to the NRC. The route survey report is assessed by the NRC and issues a route approval for the transportation of the fissile material. This technical paper will discuss the detailed processes required to obtain approvals in order to transport the HEU SLOWPOKE-2 irradiated fuel from Canada to U.S. based upon recent experiences of decommissioning SLOWPOKE-2 reactors in Canada. It will provide details on the requirements of various regulators in Canada and the U.S. that govern and regulate this shipment including transportation, safety and security. It will also present lessons learned from previous experiences that can be utilized for best practice on other similar projects. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2016

Helium-3 Production via Lithium-6 Activation in an Accelerator-Driven Reactor

In this paper, the possibility of using an accelerator-driven subcritical reactor to produce helium-3 is explored. Current supply of helium-3 in the United States is running low. Helium-3 has many applications in neutron detection, high-energy physics, and national security, and has a growing demand in the scientific community for its properties. The main source of helium-3 in the United States is from dismantling nuclear arms, where tritium is allowed to decay into helium-3. There are no current, significant future plans for increasing helium-3 production. However, the projected demand of this isotope is expected to increase dramatically, with greater research into aneutronic fusion, and allotments of helium for the Spallation Neutron Source, and ITER expected in years to come. Tritium, with a half-life of 12.3 years, will take time to decay to helium-3, which means production needs to start now to counter the future deficit. This helium-3 production system sets out to be an economical, and safe solution for this future deficit. A zirconium-lithium mixture is utilized as a target for breeding helium-3. Specifically, the target rods will consist of lithium aluminate pellets with diameters ranging from 100 to 500 microns, dispersed within a zirconium matrix. Lithium targets in pellet form were chosen over a solid rod, or annulus, in order to reduce self-shielding effects within the lithium, and to further facilitate tritium loading and containment within the zirconium. Additionally, a stainless steel 316 cladding surrounds the target rods, to further reduce outgassing of helium. The core is made up of 6480 fuel pins, enriched to 4.75% wt% U-235/U, and 3660 lithium pins in mixed assemblies arranged in hexagonal lattices, with the lithium enriched to 75% lithium-6, and a total lithium loading of approximately 70 kg. An accelerator is used as a neutron source, firing 800 MeV protons at a liquid lead target loop. Neutronics analysis and burnup calculation were performed with the aid of MCNP6. (authors)

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2016

Heated Bundle Test in AREVA Inc's Fuel Cooling Test Facility

As part the Department of Energy (DOE) initiative for advanced nuclear fuel development, AREVA Inc is performing a series of flow and thermal mixing tests on a simulated, internally heated bundle of wire-wrapped fuel pins of the type commonly used in liquid-metal fast-breeder reactors at its Fuel Cooling Test Facility (FCTF) in Richland, Washington. The FCTF is part of the Product Development Test Facility (PDTF), which is a dedicated facility for advanced thermal-hydraulic testing of nuclear fuel assemblies. Initially developed to perform post Loss Of Coolant Accident (LOCA) testing, i.e., spray and reflood tests, this test facility has been adapted to accommodate the unique requirements of the heated bundle tests described here. The purpose of this test is to investigate and measure thermal distribution and pressure drop behavior for two configurations (non-deformed and deformed duct) of heated 61-pin, hexagonally packed fast reactor test assembly in a fully turbulent regime for generating Computational Fluid Dynamics (CFD) validation grade data. This test is performed in conjunction with high fidelity flow field measurement experiments and high fidelity CFD to provide a comprehensive understanding of the flow inside such a design. The present paper focuses on the heated bundle test performed at AREVA Inc. First, the test loop is described and then an overview of the test activities is presented. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2015

Diagnosing undersampling in Monte Carlo eigenvalue and flux tally estimates - 14515

This study explored the impact of undersampling on the accuracy of tally estimates in Monte Carlo (MC) calculations. Steady-state MC simulations were performed for models of several critical systems with varying degrees of spatial and isotopic complexity, and the impact of undersampling on eigenvalue and fuel pin flux/fission estimates was examined. This study observed biases in MC eigenvalue estimates as large as several percent and biases in fuel pin flux/fission tally estimates that exceeded tens, and in some cases hundreds, of percent. This study also investigated five statistical metrics for predicting the occurrence of undersampling biases in MC simulations. Three of the metrics (the Heidelberger-Welch RHW, the Geweke Z-Score, and the Gelman-Rubin diagnostics) are commonly used for diagnosing the convergence of Markov chains, and two of the methods (the Contributing Particles per Generation and Tally Entropy) are new convergence metrics developed in the course of this study. These metrics were implemented in the KENO MC code within the SCALE code system and were evaluated for their reliability at predicting the onset and magnitude of undersampling biases in MC eigenvalue and flux tally estimates in two of the critical models. Of the five methods investigated, the Heidelberger-Welch RHW, the Gelman-Rubin diagnostics, and Tally Entropy produced test metrics that correlated strongly to the size of the observed undersampling biases, indicating their potential to effectively predict the size and prevalence of undersampling biases in MC simulations. (authors)

42 ENGINEERING↗

DOE OSTI2015

Technical basis for peak reactivity burnup credit for BWR spent nuclear fuel in storage and transportation systems - 14601

Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission have initiated a multiyear project to investigate application of burnup credit for boiling-water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase (1) investigates applicability of peak reactivity methods currently used in spent fuel pools (SFPs) to storage and transportation systems and (2) evaluates validation of both reactivity (k{sub eff}) calculations and burnup credit nuclide concentrations within these methods. The second phase will focus on extending burnup credit beyond peak reactivity. This paper documents the first phase, including an analysis of lattice design parameters and depletion effects, as well as both validation components. Initial efforts related to extended burnup credit are discussed in a companion paper. Peak reactivity analyses have been used in criticality analyses for licensing of BWR fuel in SFPs over the last 20 years. These analyses typically combine credit for the gadolinium burnable absorber present in the fuel with a modest amount of burnup credit. Gadolinium burnable absorbers are used in BWR assemblies to control core reactivity. The burnable absorber significantly reduces assembly reactivity at beginning of life, potentially leading to significant increases in assembly reactivity for burnups less than 15-20 GWd/MTU. The reactivity of each fuel lattice is dependent on gadolinium loading. The number of gadolinium-bearing fuel pins lowers initial lattice reactivity, but it has a small impact on the burnup and reactivity of the peak. The gadolinium concentration in each pin has a small impact on initial lattice reactivity but a significant effect on the reactivity of the peak and the burnup at which the peak occurs. The importance of the lattice parameters and depletion conditions are primarily determined by their impact on the gadolinium depletion. Criticality code validation for BWR burnup credit at peak reactivity requires a different set of experiments than for pressurized-water reactor burnup credit analysis because of differences in actinide compositions, presence of residual gadolinium absorber, and lower fission product concentrations. A survey of available critical experiments is presented along with a sample criticality code validation and determination of undercoverage penalties for some nuclides. The validation of depleted fuel compositions at peak reactivity presents many challenges which largely result from a lack of radiochemical assay data applicable to BWR fuel in this burnup range. In addition, none of the existing low burnup measurement data include residual gadolinium measurements. An example bias and uncertainty associated with validation of actinide-only fuel compositions is presented. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2014

Aluminum Tailor-Welded Blanks for High Volume Automotive Applications

A Design of Experiment based approach is used to systematically investigate relationships between 8 different welding factors (4 related to tool geometry, 4 related to weld process control) and resulting weld properties including strength, elongation and formability in 1.2mm-2mm thick friction stir welding of AA5182-O for TWB application. The factors that result in most significant effects are elucidated. The interactions between several key factors like plunge depth, tool tilt, pin feature and pin length on the overall weld quality is discussed. Appropriate levels of factors that lead to excellent weld properties are also identified.

Aluminum↗

DOE OSTI2020

Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

Ferroelectric domain walls, topological entities separating domains of uniform polarization, are promising candidates as active elements for nanoscale memories. In such applications, controlled nucleation and stabilization of domain walls are critical. In this work, using in situ transmission electron microscopy and phase-field simulations, a controlled nucleation of vertically oriented 109° domain walls in (110)-oriented BiFeO 3 (BFO) thin films is reported. In the switching experiment, reversed domains that are nucleated preferentially at the nanoscale edges of the “crest and sag” pattern-like electrode under external bias subsequently grow into a stable stripe configuration. In addition, when triangular pockets (with an in-plane polarization component) are present, these domain walls are pinned to form stable flux-closure domains. Phase field simulations show that i) field enhancement at the edges of the electrode causes site-specific domain nucleation, and ii) the local electrostatics at the domain walls drives the formation of flux closure domains, thus stabilizing the striped pattern, irrespective of the initial configuration. The results demonstrate how flux closure pinning can be exploited in conjunction with electrode patterning and substrate orientation to achieve a desired topological defect configuration. These insights constitute critical advancements in exploiting domain walls in next generation ferroelectronic devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2015

Polymeric Ionic Networks with High Charge Density: Solid-like Electrolytes in Lithium Metal Batteries

Polymerized ionic networks (PINs) with six ion pairs per repeating unit are synthesized by nucleophilic-substitution-mediated polymerization or radical polymerization of monomers bearing six 1-vinylimidazolium cations. PIN-based solid-like electrolytes show good ionic conductivities (up to 5.32 × 10 -3 S cm -1 at 22 °C), wide electrochemical stability windows (up to 5.6 V), and good interfacial compatibility with the electrodes.

25 ENERGY STORAGE↗

DOE OSTI2023

Defect‐Induced, Ferroelectric‐Like Switching and Adjustable Dielectric Tunability in Antiferroelectrics

Abstract Antiferroelectrics, which undergo a field‐induced phase transition to ferroelectric order that manifests as double‐hysteresis polarization switching, exhibit great potential for dielectric, electromechanical, and electrothermal applications. Compared to their ferroelectric cousins, however, considerably fewer efforts have been made to understand and control antiferroelectrics. Here, it is demonstrated that the polarization switching behavior of an antiferroelectric can be strongly influenced and effectively regulated by point defects. In films of the canonical antiferroelectric PbZrO 3 , decreasing oxygen pressure during deposition (and thus increasing adatom kinetic energy) causes unexpected “ferroelectric‐like” polarization switching although the films remain in the expected antiferroelectric orthorhombic phase. This “ferroelectric‐like” switching is correlated with the creation of bombardment‐induced point‐defect complexes which pin the antiferroelectric–ferroelectric phase boundaries, and thus effectively delay the phase transition under changing field. The effective pinning energy is extracted via temperature‐dependent switching‐kinetics studies. In turn, by controlling the concentration of defect complexes, the dielectric tunability of the PbZrO 3 can be adjusted, including being able to convert between “positive” and “negative” tunability near zero field. This work reveals the important role and strong capability of defects to engineer antiferroelectrics for new performance and functionalities.

Pan, Hao↗

DOE OSTI2015

Oxygen-Atom Transfer Chemistry and Thermolytic Properties of a Di- tert -Butylphosphate-Ligated Mn 4 O 4 Cubane

[Mn 4 O 4 {O 2 P(OtBu) 2 } 6 ] (1), an Mn 4 O 4 cubane complex combining the structural inspiration of the photosystem II oxygen-evolving complex with thermolytic precursor ligands, was synthesized and fully characterized. Core oxygen atoms within complex 1 are transferred upon reaction with an oxygen-atom acceptor (PEt 3 ), to give the butterfly complex [Mn 4 O 2 {O 2 P(OtBu) 2 } 6 (OPEt 3 ) 2 ]. The cubane structure is restored by reaction of the latter complex with the Oatom donor PhIO. Complex 1 was investigated as a precursor to inorganic Mn metaphosphate/pyrophosphate materials, which were explored by X-ray absorption spectroscopy to determine the fate of the Mn 4 O 4 unit. Under the conditions employed, thermolyses of 1 result in reduction of the manganese to Mn II species. Furthermore, the related butterfly complex [Mn 4 O 2 {O 2 P(pin)} 6 (bpy) 2 ] ( pin = pinacolate) is described.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2016

A Method to Capture Macroslip at Bolted Interfaces [PowerPoint]

Relative motion at bolted connections can occur for large shock loads as the internal shear force in the bolted connection overcomes the frictional resistive force. This macroslip in a structure dissipates energy and reduces the response of the components above the bolted connection. There is a need to be able to capture macroslip behavior in a structural dynamics model. A linear model and many nonlinear models are not able to predict marcoslip effectively. The proposed method to capture macroslip is to use the multi-body dynamics code ADAMS to model joints with 3-D contact at the bolted interfaces. This model includes both static and dynamic friction. The joints are preloaded and the pinning effect when a bolt shank impacts a through hole inside diameter is captured. Substructure representations of the components are included to account for component flexibility and dynamics. This method was applied to a simplified model of an aerospace structure and validation experiments were performed to test the adequacy of the method.

42 ENGINEERING↗

DOE OSTI2018

Remove Welding Residual Stress for CFETR Vacuum Vessel by Trailing Ultrasonic Impact Treatment

The China fusion engineering test reactor (CFETR) vacuum vessel is welded by narrow gap TIG (NG-TIG) welding, and the welding residual stress of the CFETR vacuum vessel can be redistributed by trailing welding ultrasonic impact treatment. In order to investigate the feasibility of the residual stress removing scheme, and to obtain the optimal trailing ultrasonic impact treatment technological parameters in the process of removing welding residual stress, a welding model that similar to vacuum vessel welding seam is established by using ABAQUS software, a NG-TIG welding heat source subroutine which is written in FORTRAN language used to simulate NG-TIG welding. According to the welding simulation results, a trailing welding ultrasonic impact treatment model is established, and the effects of the impact pin number, the impact method, the impact pin diameter and the impact frequency on welding residual stress are studied. The results show that the longitudinal residual stress in welding seam and its adjacent area and the lateral residual stress in the whole region have been obviously decreased by different trailing welding ultrasonic impact processes, and have made the tensile stress in the welding seam and its adjacent area has been changed into compressive stress, which can provide theoretical guidance and reference for actual production.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Irreversibility Line Measurement and Vortex Dynamics in High Magnetic Fields in Ni- and Co-Doped Iron Pnictide Bulk Superconductors

The de-pinning or irreversibility lines were determined by ac susceptibility, magnetization, radio-frequency proximity detector oscillator (PDO), and resistivity methods in Ba(Fe 0.92 Co 0.08 ) 2 As 2 ( T c = 23.2 K), Ba(Fe 0.95 Ni 0.05 ) 2 As 2 ( T c = 20.4 K), and Ba(Fe 0.94 Ni 0.06 ) 2 As 2 ( T c = 18.5 K) bulk superconductors in ac, dc, and pulsed magnetic fields up to 65 T. A new method of extracting the irreversibility fields from the radio-frequency proximity detector oscillator induction technique is described. Wide temperature broadening of the irreversibility lines, for any given combination of ac and dc fields, is dependent on the time frame of measurement. Increasing the magnetic field sweep rate (dH/dt) shifts the irreversibility lines to higher temperatures up to about dH/d t = 40,000 Oe/s; for higher dH/dt, there is little impact on the irreversibility line. There is an excellent data match between the irreversibility fields obtained from magnetization hysteresis loops, PDO, and ac susceptibility measurements, but not from resistivity measurements in these materials. Lower critical field vs. temperature phase diagrams are measured. Their very low values near 0 T indicate that these materials are in mixed state in nonzero magnetic fields, and yet the strength of the vortex pinning enables very high irreversibility fields, as high as 51 T at 1.5 K for the Ba(Fe 0.92 Co 0.08 ) 2 As 2 polycrystalline sample, showing a promise for liquid helium temperature applications.

36 MATERIALS SCIENCE↗

DOE OSTI2018

Optimization of BaHfO{sub 3} Doping Concentration as Secondary Phase in Y{sub 0.5}Gd{sub 0.5}Ba{sub 2}Cu{sub 3}O{sub 7−x} Thin Film Prepared by Pulsed Laser Deposition

BaHfO{sub 3} (BHO)-doped Y{sub 0.5}Gd{sub 0.5}Ba{sub 2}Cu{sub 3}O{sub 7−x} (YGBCO) films with a series of doping concentrations (1, 3, 5, and 10 mol%) were fabricated on CeO{sub 2} buffer layers by pulsed laser deposition (PLD) technique, and a pristine YGBCO film was also deposited at the same conditions for comparison. X-ray diffraction (XRD) results showed that the undoped and doped YGBCO films had a pure c-axis orientation. While the surface morphology and crystal quality of the BHO-doped YGBCO films deteriorated as the BHO content increased, and the critical current density (J{sub c}) at 77 K and self-field (J{sub c}{sup 77,0}) and critical transition temperature (T{sub c}) of the BHO-doped YGBCO films exhibited varying degrees of decline in comparison with the pristine YGBCO film. However, the 5 mol% BHO-doped YGBCO film exhibited greatly enhanced the J{sub c} and the highest pinning force densities (F{sub p}) at both 4.2 and 65 K, which showed the maximum value of 5776 GN/m{sup 3} (4.2 K, H//c) and 117 GN/m{sup 3} (65 K, H//c), about 1.5 times that of the undoped YGBCO film. Based on the results, the 5 mol% BHO-doped YGBCO film had the most effective flux pinning centers, which are responsible for strongly improved critical current densities in magnetic fields.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2018

Dwell Time Influence on Spark Plasma-Sintered MgB{sub 2}

Samples of MgB{sub 2} with relative density above 95% were obtained by spark plasma sintering (SPS) at 1150 °C for a heating time of 100 °C/min and a maximum pressure of 95 MPa. Dwell time was of 1, 4, 7, 10, and 20 min. Samples show that dwell time has a low influence on superconducting characteristics. However, small differences were observed and they are discussed from the viewpoint of density, structural, microstructural, critical current density, irreversibility field, and pinning type. The dominant contribution for all investigated samples is given by point and δT{sub c} pinning.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2018

X-ray Photoelectron Spectroscopy, Magnetotransport and Magnetisation Study of Nb{sub 2}PdS{sub 5} Superconductor

In the present report, we investigate various properties of the Nb{sub 2}PdS{sub 5} superconductor. Scanning electron microscopy displayed slabs like laminar growth of Nb{sub 2}PdS{sub 5} while X-ray photoelectron spectroscopy exhibited the hybridisation of sulphur (2p) with both palladium (3d) and niobium (3d). High-field (140 kOe) magneto-transport measurements revealed that superconductivity (T{sub c}{sup onset}=7 K and T cρ= 0 = 6.2 K) of the studied Nb{sub 2}PdS{sub 5} material is quite robust against magnetic field with the upper critical field (H{sub c2}) outside the Pauli paramagnetic limit. Thermally activated flux flow (TAFF) of the compound showed that resistivity curves follow Arrhenius behaviour. The activation energy for Nb{sub 2}PdS{sub 5} is found to decrease from 15.15 meV at 10 kOe to 2.35 meV at 140 kOe. Seemingly, the single vortex pinning is dominant in low-field regions, while collective pinning is dominant in high-field region. The temperature dependence of AC susceptibility confirmed the T{sub c} at 6 K, further varying amplitude and frequency, showed well-coupled granular nature of superconductivity. The lower critical field (H{sub c1}) is extracted from DC magnetisation measurements at various T below T{sub c}. It is found that H{sub c1}(T) of Nb{sub 2}PdS{sub 5} material seemingly follows the multiband nature of superconductivity.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗