South African Safety Assessment Framework for the Pebble Bed Modular Reactor

Author(s):  
Jean Joubert ◽  
Norbert Kohtz ◽  
Ian Coe

It is planned to construct a first of a kind Pebble Bed Modular Reactor (PBMR) in South Africa. A need has been recognized to accompany the licensing process for the PBMR with independent safety assessments to ensure that the safety case submitted by the applicant complies with the licensing requirements of the NNR. At the HTR 2006 Conference, the framework and major challenges on safety assessment that the South African National Nuclear Regulator (NNR) faces in developing and applying appropriate strategies and tools were presented. This paper discusses the current status of the various NNR assessment activities and describes how this will be considered in the NNR Final Report on the PBMR Safety Case. The traditional safety assessment process has been adapted to take into account the developmental nature of the project. By performing safety assessments, the designer and applicant must ensure that the design as proposed for construction and as-built meets the safety requirements defined by the regulatory framework. The regulator performs independent safety assessments, including independent analyses in areas deemed safety significant and potentially safety significant. The developmental nature of the project also led to the identification of a series of regulatory assessment activities preceding the formal assessment of the safety case. Besides an assessment of the resolution of Key Licensing Issues which have been defined in an early stage of the project and are discussed in /1/, these activities comprise the participation in an SAR Early Intervention Process, the execution of a regulatory HAZOP and the development of a regulatory assessment specification for the formal assessment of the safety case. This paper briefly describes these activities and their current status. During the last two years, significant progress was made with the development or adjustment of tools for the independent analysis by the regulator of the steady state core design, of the transient neutronic/thermal hydraulic behaviour of the reactor, of fission product release from the fuel elements, and of activation of fuel matrix and graphite impurities.

1999 ◽  
Vol 122 (2) ◽  
pp. 93-99 ◽  
Author(s):  
J. Wang ◽  
O. Kieran

The offshore installations (safety case) regulations were developed in the UK in 1992 and came into force in 1993 in response to the accepted findings of the Piper Alpha enquiry. Recently, “the offshore installations and wells (design and construction, etc.) regulations” (DCR 1996) were introduced to offshore safety analysis. From the earliest stages of the installation’s life cycle, operators must ensure that all safety-critical elements in both the software and system domains be assessed. Hazards can be identified and the risks associated with them can be assessed and evaluated using a number of techniques and decision-making strategies, all aimed at producing an installation with lifetime safety integrity. In this paper, following a brief review of the current status of offshore safety regulation in the UK, several offshore safety assessment frameworks are presented. These include top-down, bottom-up, probabilistic, and subjective approaches. The conditions under which each approach may be applied effectively and efficiently are discussed. Probabilistic safety-based decision-making and subjective safety-based decision-making are then studied. Two examples are used to demonstrate the decision-making approaches. Recommendations on further development in offshore safety analysis are suggested. [S0892-7219(00)00901-8]


Author(s):  
P. Bester ◽  
T. Hill

The electrical utility in South Africa (Eskom) plan to construct a first of a kind Pebble Bed Modular Reactor (PBMR). It has been recognized that there is a need to adapt the licensing process for the PBMR to ensure that credible and effective licensing process be developed and implemented for this technology. This paper will briefly outline the regulatory framework within South Africa, explain the licensing process adopted and present the challenges that the South African National Nuclear Regulator (NNR) was facing in developing and implementing the licensing process and how these are being addressed. The paper will discuss the update of the regulatory framework and the gaps identified in terms of regulatory requirements needed for such a project. The scope of the regulatory assessment for the licensing of the PBMR is based on the licensing requirements and criteria defined by the NNR in regulatory documents that expand on the current legislative requirements. In addition guidance is provided on selected issues in regulatory guidance documents and position papers. The requirements comprise, besides the general requirements to respect good engineering practice and the ALARA and defense-in-depth principle, specific risk criteria and radiation dose limits. These are categorized for normal operation and operational occurrences as well as for design basis events and beyond design basis events for workers and the public. Additional requirements and recommendations are stipulated by the NNR on safety important areas like quality and safety management, qualification of the nuclear fuel and the core structures, core design, verification and validation of computer codes, source term analysis and others. Selected NNR Position Papers have been developed to elaborate and provide further clarification on NNR requirements. For preparation of the PBMR safety case so-called Key Licensing Issues have been defined and agreed with the applicant. Discussions relating to these Key Licensing Issues allow important nuclear safety aspects identified for the PBMR demonstration plant to be clarified in advance of the safety case submittal.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2141 ◽  
Author(s):  
Geoff A. Freeze ◽  
Emily Stein ◽  
Patrick V. Brady ◽  
Carlos Lopez ◽  
David Sassani ◽  
...  

The safety case for deep borehole disposal of nuclear wastes contains a safety strategy, an assessment basis, and a safety assessment. The safety strategy includes strategies for management, siting and design, and assessment. The assessment basis considers site selection, pre-closure, and post-closure, which includes waste and engineered barriers, the geosphere/natural barriers, and the biosphere and surface environment. The safety assessment entails a pre-closure safety analysis, a post-closure performance assessment, and confidence enhancement analyses. This paper outlines the assessment basis and safety assessment aspects of a deep borehole disposal safety case. The safety case presented here is specific to deep borehole disposal of Cs and Sr capsules, but is generally applicable to other waste forms, such as spent nuclear fuel. The safety assessments for pre-closure and post-closure are briefly summarized from other sources; key issues for confidence enhancement are described in greater detail. These confidence enhancement analyses require building the technical basis for geologically old, reducing, highly saline brines at the depth of waste emplacement, and using reactive-transport codes to predict their movement in post-closure. The development and emplacement of borehole seals above the waste emplacement zone is also important to confidence enhancement.


1992 ◽  
Vol 22 (3) ◽  
pp. 105-116 ◽  
Author(s):  
David Edwards

This is the first of two papers on the potential contribution of health psychology to alleviating the problem of hypertension in South Africa. Educational, cognitive and behavioural strategies that can be employed as an adjunct to, or in place of, medication include: improving patients’ adherence to treatment regimens; educating and training in weight reduction, smoking cessation; healthy dietary and exercise habits; and a range of cognitive and behavioural stress management techniques. Research is reviewed, mostly from Europe and the USA, evaluating the effectiveness of these strategies, and their current status relative to the use of medication is examined.


2017 ◽  
Vol Volume 113 (Number 3/4) ◽  
Author(s):  
Phillip de Jager ◽  
Liezel Frick ◽  
Pieter van der Spuy ◽  
◽  
◽  
...  

Abstract There is a national drive to increase PhD production, yet we know little about how this imperative takes shape within different disciplines. We therefore set out to explore recent developments and the current status of the PhD in economics at four South African research-intensive universities. A data set of all economics PhDs produced in these commerce faculties during the period 2008–2014 was analysed to determine whether the departments of economics responded to the call for increased doctoral production, and the role the PhD by publication might have played in the process. How an increase in quantity might influence doctoral education in the respective academic departments was also considered by supplementing the quantitative data with perspectives from heads of department at the four institutions. The notable increase in doctoral production over the time period studied shows that national and international trends have influenced doctoral education in economics departments within South African research-intensive universities. Increased usage of the PhD by publication has implications for policy and pedagogical practice within these departments, especially as there seems to be limited available supervisory capacity. Other changes in departmental practices, such as the entrenchment of a research culture and the promotion of collaborative research amongst students and staff, also contributed to maintain quality in doctoral education.


2014 ◽  
Vol 33 (3_suppl) ◽  
pp. 48S-83S ◽  
Author(s):  
Monice M. Fiume ◽  
Wilma F. Bergfeld ◽  
Donald V. Belsito ◽  
Ronald A. Hill ◽  
Curtis D. Klaassen ◽  
...  

The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 24 Vitis vinifera (grape)-derived ingredients and found them safe in the present practices of use and concentration in cosmetics. These ingredients function in cosmetics mostly as skin-conditioning agents, but some function as antioxidants, flavoring agents, and/or colorants. The Panel reviewed the available animal and clinical data to determine the safety of these ingredients. Additionally, some constituents of grapes have been assessed previously for safety as cosmetic ingredients by the Panel, and others are compounds that have been discussed in previous Panel safety assessments.


Author(s):  
Ievgen Babeshko ◽  
Kostiantyn Leontiiev

Safety assessment of nuclear power plant instrumentation and control systems (NPP I&Cs) is a complicated and resource-consuming process that is required to be done so as to ensure the required safety level and comply to normative regulations. A lot of work has been performed in the field of application of different assessment methods and techniques, modifying them, and using their combinations so as to provide a unified approach in comprehensive safety assessment. Performed research has shown that there are still challenges to overcome, including rationale and choice of the safety assessment method, verification of assessment results, choosing and applying techniques that support safety assessment process, especially in the nuclear field. This chapter presents a developed framework that aggregates the most appropriate safety assessment methods typically used for NPP I&Cs.


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