atw - August/September 2017

NucNet

NucNet spoke to Vladimir Kriventsev, team leader for fast reactor technology development at the International Atomic Energy Agency (IAEA), about the possibilities and challenges of technology development in the fast reactor sector. Today, the field of fast reactors is vibrant and full of fascinating developments, some which will have an impact in the nearer term and others in the longer term.

NucNet

The past year saw a number of anticipated developments related to Germany’s policy of phasing out nuclear power by 2022. Ralf Güldner, president of the German Atomic Forum (DAtF), spoke to NucNet about what has been accomplished and what remains to be done in Germany half way down the phaseout path. 

Jonathan Cobb

World Nuclear Association recently published the 2017 edition of the World Nuclear Performance Report. The report presents key metrics that illustrate current performance, both of reactors currently operating and those under construction. The article highlights some of the most important findings of the report. The pace of new build will need to accelerate if nuclear energy is going to make a growing contribution to the global electricity generation mix, a requirement of many projections of future scenarios that aim to meet the objective of limiting the rise average temperatures to below two degrees Celsius, while at the same time meeting the growing worldwide demand for electricity.

Tomasz R. Nowacki

In the July 2016 issue of atw an article has been published on the legal obstacles to the construction of HTRs in Poland . The authors have raised a number of objections to the Polish law with the main thesis of the inability, or at least a significant impediment to the construction of such installations without significant legislative intervention. The main purpose of this text is to prove that the construction of HTRs based on the existing Polish laws and regulations is possible. In addition, the author intends to clarify the particular concerns expressed in the article regarding the particular legislation and correct improper statements and interpretations of the Polish nuclear law. The article deals only with strictly legal issues and does not take a stand on the technical feasibility and reality of ambitious plans for the construction of HTRs in Poland.

Tobias Leidinger

With the decision of the Federal Constitutional Court (BVerfG, file number 2 BvL 6/13) published on 7 June the Federal Constitutional Court has “tipped” the so-called nuclear fuel tax levied by nuclear power plant operators from 2011 to the end of 2016 (tax revenues approx. 6.285 billion Euros). According to the court the Federal legislature does  not has any legislative competence for the introduction of this tax. Including interest rates, the current tax debtors E.ON, RWE and EnBW are now refunded a total of just under € 7 billion of wrongly levied taxes for the years 2011 to 2016. In substance, the decision on the unconstitutionality and invalidity of the nuclear fuel tax is a threefold big bang.

F. Roelofs, A. Shams, A. Batta, V. Moreau, I. Di Piazza, A. Gerschenfeld, P. Planquart and M. Tarantino

The European Sustainable Nuclear Industry Initiative (ESNII) aims at industrial application of fast reactor technology for a sustainable nuclear energy production. Currently four demonstration projects have a promising outlook in Europe, i.e. the ASTRID project in France, the MYRRHA project in Belgium, the ALFRED pan-European project to be realized in Romania, and SEALER in Sweden. Sodium and lead(-alloys) are envisaged as coolants for these reactors. Obviously, in the development of these reactors, thermal-hydraulics is recognized as a key challenge with emphasis on safety issues. This paper discusses the state-of-the-art knowledge with respect to experiments and simulation techniques as pursued in the Horizon 2020 SESAME (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors) project.

Minhee Kim and Seyun Kim

A total loss of feedwater (TLOFW) with additional failures in ATLAS test facility was analyzed using SPACE code, which is an advanced thermal-hydraulic system analysis code developed by the Korea nuclear industry. Partial failure of the safety injection pumps (SIPs) and the pilot-operated safety relief valves (POSRVs) of pressurizer were selected as additional failures. In order to assess the capability of SPACE code, partial failure was modeled, and compared with results of OECD-ATLAS A3.1 results. Reasonably good agreement with major thermal-hydraulic parameters was obtained by analyzing the transient behavior. From the results, this indicated that SPACE code has capabilities to design extension conditions, and feed and bleed operation using POSRVs and SIPs were effective for RCS cooling capability during TLOFW.

Bernhard Kienzler

In the period between 1980 and 2004, corrosion studies on various metallic materials have been performed at the Research Center Karlsruhe. The objectives of these experimental studies addressed mainly the performance of canister materials for heat producing, high-level wastes and spent nuclear fuels for a repository in a German salt dome. Additional studies covered the performance of steels for packaging wastes with negligible heat production under conditions to be expected in rocksalt and in the Konrad iron ore mine. The results of the investigations have been published in journals and conference proceedings but also in “grey literature”. This paper presents a summary of the results of corrosion experiments with fine-grained steels and nodular cast steel.

Lutz Niemann

The “Cobalt 60 Case” in Taiwan gives an opportunity for check of the thesis of radiation hormesis. Apartment residents have been exposed to cobalt-60 contaminated steel buildings. The results of a study strongly suggest that whole-body chronic irradiation, in the dose rate range that the apartment residents received, caused no symptomatic adverse health effects, such as radiation sickness, or the increased cancer or increased congenital disease that are predicted by ICRP theories. On the contrary, those who were exposed had lower incidences of cancer mortality and congenital malformations.

Christian Raetzke

Summary report on the Key Topic Outstanding Know-How & Sustainable Innovations, Focus Session: International Regulation: Leveraging the Experience of Established Nuclear Countries for Regulations and Projects in Newcomer Countries, of the 48th Annual Meeting on Nuclear Technology (AMNT 2017) held in Berlin, 16 to 17 May 2017.

John Shepherd

After years of argument and delay could the US be edging closer to resurrecting proposals to build a national repository for high level nuclear waste (HLW) at Yucca Mountain in Nevada? The federal government has looked at the site with a view to establishing a repository since the 1970s. However, after pouring billions of dollars into projects and studies over the decades, the project remained bogged down in legal battles and opposition from politicians and pressure groups. Now, the US Nuclear Regulatory Commission (NRC) said it had directed its staff to use the equivalent of about EUR 95,000 from the national Nuclear Waste Fund on “information-gathering activities” that could pave the way for resuming a licensing review of Yucca Mountain as a potential deep geologic repository (DGR).