The Scientific Contribution of the Kaniadakis Entropy to Nuclear Reactor Physics: A Brief Review.

In nuclear reactors, tracking the loss and production of neutrons is crucial for the safe operation of such devices. In this regard, the microscopic cross section with the Doppler broadening function is a way to represent the thermal agitation movement in a reactor core. This function usually considers the Maxwell-Boltzmann statistics for the velocity distribution. However, this distribution cannot be applied on every occasion, i.e., in conditions outside the thermal equilibrium. In order to overcome this potential limitation, Kaniadakis entropy has been used over the last seven years to generate generalised nuclear data. This short review article summarises what has been conducted so far and what has to be conducted yet.

An economical viable tokamak fusion reactor based on the ITER experience.

This is my personal vision and outlook towards a fusion reactor based on my extensive experience from being part of the ITER design, and now construction, as well as leading the largest fusion technology program worldwide (KIT-Karlsruhe Institute of Technology) for 7 years. In particular, I want to discuss how a fusion reactor can be economically viable without employing too advanced physics and technology. It certainly will be a pulsed machine (approx. 20 000 s pulses) with thermal energy storage (turbine is steady state). I also want to discuss the optimum machine size and toroidal field for such a machine and why I think that high field and smaller plasmas may not necessarily make a fusion reactor more competitive. When one extrapolates from today's knowledge on ITER construction, even considering that ITER can be built much cheaper, it is clear that a fusion power plant will cost more than 10 or more likely more than 15 billion Euros/Dollars (the first of a kind even approx. 30 billion). Therefore, in order to have an economically attractive fusion reactor, it needs to produce a large amount of power (on the order of 2.5 GW electric). The possible size (R ∼ 10 m) and reasonably conservative physics basis of such a machine will be briefly described in the presentation. If we are successful in achieving advanced physics in a burning plasma, e.g. in ITER, then we can make the machine slightly smaller but the principal arguments for a large machine will not change significantly. Key technologies and their status will be discussed with particular emphasis on a realistic blanket and divertor design and the size and issues of a tritium-plant (T-plant) for such a machine as well as the challenges which have to be overcome beyond what is needed for ITER. Finally, a simple economic consideration will be discussed to show that a large machine could be economically viable, even in today's environment, in particular, in competition with renewables. This article is part of a discussion meeting issue 'Fusion energy using tokamaks: can development be accelerated?'.

Upper limits on perturbations of nuclear decay rates induced by reactor electron antineutrinos.

We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos (ν¯e) can alter the rates of weak nuclear interaction induced decays of 54Mn, 22Na, and 60Co. This experiment has small statistical errors but, when systematic uncertainties are included, has null results. Perturbations greater than one part in 104 are excluded at 95% confidence level in ß± decay and electron capture processes, in the presence of an antineutrino flux of 3 × 1012 cm-2s-1. The present experimental methods are applicable to a wide range of radionuclides. Improved sensitivity in future experiments can be anticipated as we continue to better understand and reduce the dominant systematic uncertainties.

Nuclear power in the 21st century: Challenges and possibilities.

The current situation and possible future developments for nuclear power--including fission and fusion processes--is presented. The fission nuclear power continues to be an essential part of the low-carbon electricity generation in the world for decades to come. There are breakthrough possibilities in the development of new generation nuclear reactors where the life-time of the nuclear waste can be reduced to some hundreds of years instead of the present time-scales of hundred thousand of years. Research on the fourth generation reactors is needed for the realisation of this development. For the fast nuclear reactors, a substantial research and development effort is required in many fields--from material sciences to safety demonstration--to attain the envisaged goals. Fusion provides a long-term vision for an efficient energy production. The fusion option for a nuclear reactor for efficient production of electricity has been set out in a focussed European programme including the international project of ITER after which a fusion electricity DEMO reactor is envisaged.

The MARVEL assembly for neutron multiplication.

A new multiplying test assembly is under development at Idaho National Laboratory to support research, validation, evaluation, and learning. The item is comprised of three stacked, highly-enriched uranium (HEU) cylinders, each 11.4 cm in diameter and having a combined height of up to 11.7 cm. The combined mass of all three cylinders is 20.3 kg of HEU. Calculations for the bare configuration of the assembly indicate a multiplication level of >3.5 (k(eff)=0.72). Reflected configurations of the assembly, using either polyethylene or tungsten, are possible and have the capability of raising the assembly's multiplication level to greater than 10. This paper describes simulations performed to assess the assembly's multiplication level under different conditions and describes the resources available at INL to support the use of these materials. We also describe some preliminary calculations and test activities using the assembly to study neutron multiplication.