_Akademik Lomonosov: Preparation for Premiere in Full Swing
_Westinghaouse EnCore Accident Tolerant Fuel
_Neutron Flux Fluctuation in PWR
_Coated Ceramic Honeycomb Type Passive Autocatalytic Recombiner
_Young Scientists Workshop
NucNet, David Dalton
The US has the largest number of
nuclear plants in the world – 99 in commercial operation at the time of writing
– but its global leadership position is said to be declining as efforts to
build a new generation of reactors have been plagued by problems, and aging
plants have been retired or closed in the face of economic, market, and
financial pressures. A recent report by the Atlantic Council issued a stark
warning, arguing that the US nuclear energy industry is facing a crisis that
the Trump administration must immediately address as a core part of its “all of
the above” energy strategy.
the end of July 2018, the loading of the floating power unit Akademik Lomonosov
with nuclear fuel started in Murmansk. This is one of the key stages of the
project, which as of today has no analogues in the world. In 2019, the power
unit will begin to supply local population and industrial facilities in
North-Eastern Siberia with heat and electricity. The project is expected to
open up opportunities for the mass production of floating nuclear power plants
– a number of countries have already voiced their interest. The Akademik
Lomonosov is intended for providing
energy to remote industrial facilities, port cities, as well as gas and oil
platforms located on the high seas.
Shortly before it was passed, the legislature reacted to the constitutional deficiencies which the Federal Constitutional Court (BVerfG) objected to in its judgment of 6 December 2016 on the nuclear phase-out (BVerfGE 143, 246) and for which a constitutional situation had to be established by 30 June 2018. However, the newly created compensation regulations in the 16th amendment to the Atomic Energy Act raise new legal questions, especially those relating to their constitutionality.
Gilda Bocock, Robert Oelrich and Sumit Ray
The development and
implementation of accident tolerant fuel (ATF) products, such as Westinghouse’s
EnCore® Fuel, can support the long-term viability of nuclear energy by
enhancing operational safety and decreasing energy costs. The first
introduction of Westinghouse EnCore Fuel into a commercial reactor is planned for
2019 as segmented lead test rods (LTRs) utilizing chromium-coated zirconium
cladding with uranium silicide (U3Si2) pellets. The EnCore Fuel lead test assembly (LTA)
program, with LTAs planned for 2022 insertion, will introduce silicon
carbide/silicon carbide composite cladding with U3Si2
Joachim Herb, Christoph Bläsius, Yann Perin, Jürgen Sievers and Kiril Velkov
During the last 15 years the
neutron flux fluctuation levels in some of the German PWR changed
significantly. During a period of about ten years, the fluctuation levels
increased, followed by about five years with decreasing levels after taking
actions like changing the design of the fuel elements. The increase in the
neutron flux fluctuations resulted in an increased number of triggering the
reactor limitation system and in one case in a SCRAM. Several models based on
single physical effects are used to simulate the neutron flux. Each of these simple
models can reproduce some of the characteristics of the observed neutron flux
G. Girardin, R. Meier, L. Meyer, A. Ålander and F. Jatuff
investigations on measured neutron flux noise at the Kernkraftwerk
Gösgen-Däniken are summarised. The NPP in operation since 1979 is a German KWU
pre-KONVOI, 3-Loop PWR with a thermal power of 3,002 MWth (1,060 MWe). In a
period of approx. 7 cycles from 2010 to 2016, an increase of the measured
neutron noise amplitudes in the in- and out-core neutron detectors has been
observed, although no significant variations have being detected in global
core, thermohydraulic circuits or instrumentation parameters. Verifications of
the instrumentation were performed and it was confirmed that the neutron flux
instabilities increased from cycle to cycle in this period. In the last two
years, the level of neutron flux noise remains high but seems to have achieved
a saturation state.
Chang Hyun Kim, Je Joong Sung, Sang Jun Ha and Phil Won Seo
the containment integrity during a severe accident in nuclear power reactor by
maintaining the hydrogen concentration below an acceptable level has been
recognized to be of critical importance after Fukushima Daiichi accidents.
Although there exist various hydrogen mitigation measures, a passive
autocatalytic recombiner (PAR) has been considered as a viable option for the
mitigation of hydrogen risk under the extended station blackout conditions
because of its passive operation characteristics for the hydrogen removal. As a
post-Fukushima action item, all Korean nuclear power plants were equipped with
PARs of various suppliers. The capacity and locations of PAR as a hydrogen
mitigation system were determined through an extensive analysis for various
severe accident scenarios.
During the Young Scientists
Workshop of the 49th Annual Meeting on Nuclear Technology (AMNT
2018), 29 to 30 May 2018, Berlin, 13 young scientists presented results of
their scientific research as part of their Master or Doctorate theses covering
a broad spectrum of technical areas. Vera Koppers, Katharina Amend and Maria
Freiria were awarded for their presentations by the jury.
Vera Koppers and Marco K. Koch
A new method for rapid and
reliable modelling of research reactors for deterministic safety analysis is
presented. A rule-based software system is being developed to support the
modelling process in ATHLET for selected research reactor types in the light of
limited available data. The fundamental elements of the input deck are
generated automatically by few input data necessary.
Katharina Amend and Markus Klein
The research project aims to
develop a CFD model to describe the run down behavior of liquids and the
resulting wash-down of fission products on surfaces in the reactor containment.
The paper presents a three-dimensional numerical simulation for water running
down inclined surfaces coupled with an aerosol wash-off model and particle
transport using OpenFOAM. The wash-off model is based on Shields criterion. A
parameter variation is conducted and the simulation results are compared to
María Freiría López, Michael Buck and Jörg Starflinger
A conservative criticality
evaluation of Fukushima Unit 1 debris bed has been carried out. In order to
obtain a multi-dimensional criticality map, parameters, such as debris size,
porosity, particle size, fuel burnup, water density and boration were varied.
As a result, safety parameter ranges where recriticality can be excluded have
been identified. It was found that most of the possible debris would be
inherently subcritical because of its porosity and 1600 ppm B would ensure
subcriticality under any conditions.
The report summarises the
presentations of the Focus Session International Regulation | Radiation Protection:
The Implementation of the EU Basic Safety Standards Directive 2013/59 and the
Release of Radioactive Material from Regulatory Control presented at the 49th
AMNT 2018, Berlin, 29 to 30 May 2018.
Klemens Hummelsheim, Florian Rowold and Maik Stuke
Conference report on the GRS Workshop “Safety of Extended Dry Storage of Spent Nuclear Fuel”, 6 to 8 June 2018.
The time of year always means all manner of weird and wonderful stories finding their way into the news. For the nuclear industry, the hot spell fanned the media flames of an old anti-nuclear favourite, as it became clear operations at some nuclear power plants were being halted temporarily to comply with restrictions that prevent cooling water further heating local rivers and waterways. It’s a question why the nuclear community does not use the time of year to communicate their important and interesting topics.