Development and Analysis of Scenarios for a Permanent Repository for Radioactive Wastes in Salt Rock

2000 ◽  
Vol 663 ◽  
Author(s):  
S. Keller

ABSTRACTScenarios were developed and analyzed as part of a long-term safety analysis of a permanent repository for radioactive wastes. A procedure is described by which features, events, and processes (FEP) at a specific site can be evaluated for the long-term safety assessment of a permanent repository for radioactive waste. These FEPs can be weighted according to selected criteria and combined to scenarios using a conceptual model of the site.

1988 ◽  
Vol 127 ◽  
Author(s):  
H. P. Berg ◽  
D. Ehrlich ◽  
B. Thomauske

ABSTRACTRequirements on radioactive waste of negligible heat generation with respect to transuranic elements, derived from the safety analysis of the operational phase of the Konrad repository, are described and resulting activity limitations are discussed. For assessing the long term safety, the calculation of individual doses in connection with the very slow water movements and, additionally, toxicity comparisons to other waste and to the natural toxicity at the site are discussed. Some information is given on the procedure of taking into account the activity limitations in an optimal way when planning emplacement campaigns.


Author(s):  
Mick Bacon ◽  
Doug Ilett ◽  
Andy Whittall

In 2006 the UK Governments response to recommendations by its Committee on Radioactive Waste Management (CoRWM) established, in England and Wales, that geological disposal, supported by safe and secure interim storage, is the preferred route for the long-term management of higher-activity radioactive waste (i.e. that which is not suitable for near-surface disposal). It also gave the responsibility for delivering the programme for a deep geological repository to the Nuclear Decommissioning Authority (NDA). The Scottish Government has a policy of long term, near site, near surface safe and secure interim storage. To support the open and transparent approach promised by Government, the Health and Safety Executive (HSE), the Environment Agency and the Scottish Environment Protection Agency (SEPA) are developing joint guidance on the management of higher-activity radioactive waste to explain regulatory objectives in securing safe and secure interim storage and the associated management of radioactive wastes. The guidance comes in two parts: • Guidance on the regulatory process; • Technical guidance modules. The guidance promotes a cradle to grave approach to radioactive waste management and by aligning the regulatory interests of environmental and safety regulators it delivers one of the Government’s “Better Regulation” objectives. This paper describes the process by which the joint guidance was produced with particular emphasis on stakeholder engagement. It describes the key features of the guidance, including the concept of the radioactive waste management case (RWMC). Finally the problems encountered with dissemination and implementation are discussed together with measures taken by the regulators to improve these aspects.


2008 ◽  
Vol 161 (2) ◽  
pp. 156-168 ◽  
Author(s):  
J. Mazeika ◽  
R. Petrosius ◽  
V. Jakimaviciute-Maseliene ◽  
D. Baltrunas ◽  
K. Mazeika ◽  
...  

MRS Advances ◽  
2016 ◽  
Vol 1 (61) ◽  
pp. 4075-4080
Author(s):  
Fredrik Vahlund

ABSTRACTSince 1988 the Swedish Nuclear Fuel and Waste Management Co. operates a repository for low- and intermediate-level short-lived radioactive waste, SFR, in Forsmark, Sweden. Due to decommissioning of the nuclear power plants additional storage capacity is needed. In December 2014, an application to extend the repository was therefore submitted. One key component of this application was an assessment of post-closure safety of the extended SFR. For this safety assessment, a methodology based on that developed by SKB for the spent nuclear fuel repository was used and the impact of the degradation of repository components, the evolution of the surface system and changes of future climate on the radiological safety of the repository was assessed over a period of 100,000 years. The central conclusion of the SR-PSU safety assessment is that the extended SFR repository meets requirements on protection of human health and of the environment that have been established by the Swedish radiation safety authority for the final disposal of radioactive waste. Furthermore, the design of the repository was shown suitable for the waste selected and the applied methodology suitable for the safety assessment.


2020 ◽  
Vol 195 ◽  
pp. 03043
Author(s):  
Zhixiong Zeng ◽  
Yu-Jun Cui ◽  
Nathalie Conil ◽  
Jean Talandier

Compacted MX80 bentonite/Callovo-Oxfordian (COx) claystone mixture has been considered as a possible sealing/backfilling material in the French deep geological radioactive waste disposal. The swelling pressure of such mixture is an important factor in the design and long-term safety assessment of deep geological repositories. In this study, constant-volume swelling pressure tests were performed on the mixtures with different claystone fractions and dry densities. The test results show that the swelling pressure of the mixtures decreased with the increasing claystone fraction and decreasing dry density. According to the experimental results, the contribution of claystone to the global swelling pressure was further investigated. It was found that the deformation of claystone and its contribution to swelling pressure was highly dependent on the claystone fraction. As the claystone fraction was larger than 30%, the claystone in the mixture swelled, contributing to the global swelling pressure; On the contrary, as the claystone fraction was less than 30%, the swelling of claystone was inhibited by the bentonite and it worked an inert material without any contribution to the swelling pressure.


1968 ◽  
Vol 1 (4) ◽  
pp. T72-T79 ◽  
Author(s):  
G. Hensley

Safeguards, for costly and hazardous chemical plants, are often provided by means of alarm or automatic shutdown systems. The adequacy of this protection—which is a measure of the capability of the newly installed system in shutting down the plant on the occurrence of a hazardous condition, and its effectiveness over the long term (its reliability)—may be judged by an independent safety assessment. Both qualitative and quantitative aspects of safety analysis are involved in an assessment, the quantitative approach being of particular use where there is a need to compare the anticipated reliability of the proposed system with a numerically specified, reliability requirement. Some of the techniques used in the assessment procedure are discussed in the paper and, by way of example, the performance of a typical shutdown system is assessed and its adequacy judged against a hypothetical plant fault condition.


2016 ◽  
pp. 61-64
Author(s):  
I. Iarmosh ◽  
Yu. Olkhovyk

For development of the management strategy for radioactive waste to be placed in near-surface disposal facilities (NSDF), it is necessary to justify long-term safety of such facilities. Use of mathematical modelling methods for long-term forecasts of radwaste radiation impacts and assessment of radiation risks from radionuclides migration can help to resolve this issue. The purpose of the research was to develop the conceptual model for determining the maximum activity of radwaste to be safely disposed in the NSDF and to test it in the case of Lot 3 Vector NSDF (Chornobyl exclusion zone). This paper describes an approach to the development of such a model. The conceptual model of 90Sr migration from Lot 3 through aeration zone and aquifer soils was developed. The results of modelling are shown. The proposals on further steps for the model improvement were developed.


Author(s):  
L. B. Prozorov ◽  
S. A. Korneva

As part of a development program for radioactive waste management, two test boreholes have been constructed at the MosNPO “Radon” Site to evaluate the conditions of LILW storage in such facilities, to observe the behaviour of engineered barriers as a function of time, the ability of the system to contain radionuclides and to test the reliability of a monitoring system. To obtain a licence for operation of such boreholes, MosNPO “Radon” specialists have prepared a package of documents, including a “Report on Safety Assessment of LILW Storage in Large Diameter Boreholes” [1]. On the basis of radiation safety standards and requirements being in force in Russian Federation, a range of possible accidents and emergencies during the operational period has been considered in this study. In this paper, the authors present results of a long term safety assessment of LILW disposal in the boreholes, performed within the framework of the above mentioned report.


Author(s):  
Samantha King

Nirex is the organisation responsible for long-term radioactive waste management in the UK. Our mission is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. Nirex is therefore researching various options for the long-term management of radioactive wastes/materials in order to identify the relevant issues with regard to the feasibility of options, and the research, development and stakeholder dialogue necessary to address these issues. The UK policy for the long-term management of solid radioactive waste is currently undergoing review. In September 2001, the UK Government Department for Environment, Food and Rural Affairs (Defra) and the Devolved Administrations for Scotland, Wales and Northern Ireland launched a public consultation on ‘Managing Radioactive Waste Safely’ (MRWS) [1]. The aim of this consultation was to start a process that will ultimately lead to the implementation of a publicly acceptable radioactive waste management policy. The MRWS programme of action proposed by Government includes a “stakeholder” programme of public debate backed by research to examine the different radioactive waste management options, and to recommend the preferred option, or combination of options. The options of storage above ground and underground are expected to be among the options examined. In the UK, radioactive wastes are currently held in surface stores, at over 30 locations in the UK, pending a decision on their long-term management. These stores were originally designed to have lifetimes of up to 50 years, but due to uncertainty regarding the longer term management of such wastes, extending the life of stores to 100 years is now being considered. This paper describes a preliminary scoping study to identify the long-term issues associated with surface storage of intermediate-level radioactive waste (ILW), and certain low-level waste (LLW) indefinitely in the UK. These wastes contain radionuclides with half lives that can range up to a million years or more, it was therefore assumed, for the purposes of this scoping study, that wastes would need to be managed over a period of at least one million years. An indefinite surface storage concept will require institutional stability and encompasses the principle of guardianship. It is based on a rolling present where each generation is required to monitor and, as necessary, repackage the waste and refurbish/replace storage buildings over a period of at least one million years. Each generation will also need to decide whether to continue with surface storage or implement another long-term management option. The aims of the scoping study were to: i) Investigate the implications of indefinite surface storage of waste packages through consideration of the facility specification, design and assessment. This framework is common to all Nirex radioactive waste management option studies, and provides a common basis for comparison. ii) Identify the social and ethical issues related to indefinite storage, including the principles and values that some stakeholders believe are met by the surface storage option.


Radiocarbon ◽  
2018 ◽  
Vol 60 (6) ◽  
pp. 1657-1670 ◽  
Author(s):  
J Mibus ◽  
N Diomidis ◽  
E Wieland ◽  
S W Swanton

ABSTRACTCarbon-14 (radiocarbon,14C) is an important radionuclide in the inventory of radioactive waste in many disposal programs due to its significant dose contributions in safety assessments for geological repositories. Activated steels from nuclear reactors are one of the major sources of14C. Knowledge of14C release from steel wastes and its chemical form (speciation) is limited giving rise to uncertainty regarding the fate of14C and a conservative treatment in assessment calculations. In this work, we summarize and make a synthesis of selected results from Work Package 2 of the EU CAST project aiming to improve understanding of14C release related to steel corrosion under repository-relevant conditions. The outcome of the experiments is discussed in the context of the long-term evolution of a repository and its potential consequences for safety assessment.


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