13 November 2017
Noise appears in many areas of science, and commonly has an unwanted and disturbing nature by deteriorating signals’ quality. Therefore, various techniques have been developed over the years for separating noise from pure signals. However, noise has a key role in signal analysis of nuclear reactors as its’ appropriate assessment can be used not only for exploring the normal and dynamic behaviour of nuclear cores, but also for identifying and detecting possible anomalies of reactor systems. State of the art methods have been recently implemented within the well-established signal analysis methodology of the STARS program
, at the Laboratory for Reactor Physics and Systems Behaviour (LRS
), for investigating nuclear reactor noise and getting a better insight on analysing reactors’ operation.
3 October 2017
The formation and growth of cracks by stress corrosion cracking (SCC)in reactor internals and recirculation pipes due to the highly oxidising environment is a serious issue in boiling water reactors. At first, SCC mitigation was attempted by injecting H2
into the feed water, where the injected H2
recombines with the H2
to water and reduces the electrochemical corrosion potential, and consequently the SCC susceptibility. Several disadvantages of the injection of high amounts of H2
, have led to the development of noble metal additions to the reactor feed water. With injection of a much smaller amount of H2
, the noble metal particles of a few nanometres in size, formed in-situ, work as catalysts for the efficient reduction of the oxidizing species formed by radiolysis, and thus lower the ECP and SCC susceptibility.
15 September 2017
The credibility of long-term safety assessments of radioactive waste repositories may be greatly enhanced by a molecular level understanding of the sorption processes onto individual minerals present in the near- and far-fields. A study conducted at LES
in collaboration with the Helmholtz Zentrum Dresden Rossendorf
used extended X-ray absorption fine structure (EXAFS) and time-resolved laser fluorescence spectroscopies (TRLFS) to elucidate the uptake mechanism of trivalent lanthanides and actinides (Ln/AnIII
) by the clay mineral montmorillonite.The excellent agreement between the thermodynamic model parameters obtained by fitting the macroscopic data, and the spectroscopically identified mechanisms, demonstrates the mature state of the 2SPNE SC/CE sorption model developed at LES
for predicting and quantifying the retention of Ln/AnIII
elements by montmorillonite-rich clay rocks.
19 April 2017
BKW’s Engineering Division and the Paul Scherrer Institute (PSI) joined forces to provide risk and safety analysis services in the nuclear sector. By combining their expertise, the two companies are able to solve highly complex problems in the field of nuclear safety. The range of joint services is aimed at customers from the power plant sector and supply industry, as well as public and state institutions. The collaboration will focus exclusively on the international (non-Swiss) market.
9 February 2017
Environment Energy and Environment Renewable Energies ESI Platform
The Laboratory for Energy Systems Analysis at the Paul Scherrer Institute PSI is investigating how Switzerland’s electricity supply might look, up to the year 2050, under a variety of boundary conditions. On the basis of their calculations, the lab’s researchers are able to generate insights on possible future developments of the energy sector, for example, determine how an ambitious reduction in CO2
emissions could be achieved at the lowest possible cost.