Experiments and Modelling Studies Concerning Localised Corrosion of Carbon Steel and Stainless Steel Containers for Intermediate- and Low-Level Radioactive Waste

1992 ◽  
Vol 294 ◽  
Author(s):  
A.R. Hoch ◽  
C.C. Naish ◽  
S.M. Sharland ◽  
A.C. Smith ◽  
K.J. Taylor
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Radioactive Waste ◽  
Pitting Corrosion ◽  
Environmental Conditions ◽  
Crevice Corrosion ◽  
Experimental Studies ◽  
Modelling Studies ◽  
The Uk ◽  
Low Level Radioactive Waste

ABSTRACTCurrent plans for disposal of low- and intermediate-level radioactive wastes (LLW and ILW) in the UK include enclosing much of the waste in carbon steel or stainless steel containers. Modelling and experimental studies that aim to characterise the period and extent of the localised corrosion in these containers are described. The period, during which localised corrosion can be initiated and sustained in the post-closure phase of the repository is estimated. The likely modes of localised corrosion are identified, based on further consideration of the environmental conditions to which the metals are exposed. Detailed research in progress includes investigation of the rate of pitting corrosion for carbon steel, and the possible occurrence of crevice corrosion of stainless steel.

scholarly journals Near-field/Far-field Interface of a Near-Surface Low-Level Radioactive Waste Site

2003 ◽  
Vol 807 ◽  
Author(s):  
I. R. Beadle ◽  
J. Graham ◽  
S. Boult ◽  
V. L. Hand ◽  
P. Warwick ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Iron Hydroxide ◽  
Near Field ◽  
Experimental Studies ◽  
Far Field ◽  
Near Surface ◽  
Interface Zone ◽  
Low Level ◽  
Modelling Studies ◽  
Low Level Radioactive Waste

ABSTRACTExperimental and Modelling studies have been used to investigate the biogeochemical processes occurring at the interface zone between the near-field and far-field of the Drigg Low-Level radioactive Waste (LLW) trenches. These have led to a conceptual model of interface biogeochemistry, which has subsequently been modelled by the BNFL code known as the Generalised Repository Model (GRM). GRM simulations suggest that as organic rich leachate migrates into the far-field, iron III minerals such as iron hydroxide will dissolve, and reduced iron minerals such as siderite will precipitate due to microbial processes. Batch and column experimental studies have verified this conceptual understanding. Some unexpected processes, such as the presence of nitrate enhancing sulphate reduction, were also observed

Independent Monitoring of Solid Low Level Radioactive Waste Disposals in the UK

2003 ◽  
Author(s):  
S. R. Daish ◽  
N. A. Leech
Keyword(s):  
United Kingdom ◽  
Radioactive Waste ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Low Level ◽  
The United Kingdom ◽  
Environment Agency ◽  
The Uk ◽  
Non Destructive ◽  
Low Level Radioactive Waste

The independent monitoring of solid low level radioactive waste (LLW) in the United Kingdom is undertaken by NNC Limited on behalf of The Environment Agency to ensure that disposals are within the authorised limits. Waste consignments are seized by the Agency prior to disposal and are transported to the Waste Quality Checking Laboratory (WQCL) at Winfrith, where the contents are analysed and assessed by destructive and non-destructive testing. All work performed at the laboratory is qualified by a Quality Assurance System which has been accredited by the United Kingdom Accreditation Service (UKAS). This paper outlines the regulatory framework for control of LLW disposals in the UK and describes the techniques used at WQCL for radioactive waste assessment.

Experimental Studies of Ratcheting of Pressurized Pipe

1991 ◽  
Vol 113 (2) ◽  
pp. 210-218 ◽  
Author(s):  
R. J. Scavuzzo ◽  
P. C. Lam ◽  
J. S. Gau
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Experimental Studies ◽  
Initial Pressure ◽  
Steel Pipe ◽  
304 Stainless Steel ◽  
Dynamic Tests ◽  
Stainless Steel Pipe ◽  
Bending Stresses ◽  
Hoop Direction

In these studies, both dynamic and static tests were conducted on pressurized pipe. Dynamic tests were run on 1 in. Schedule 40 and Schedule 10 seamless 304 stainless steel pipe. Welded 1 in. Schedule 40 304 stainless steel pipe and seamless carbon steel (ASTM A106) pipe were tested statically. Internal pressures varied from 1000 psi to 3000 psi. In these tests, axial bending stresses from either inertial loads or static loads were superposed on to the initial pressure stresses. Strain gages were used to measure the cyclic strains on the outer walls of the pipe. Measurements indicated that ratcheting occurred primarily in the hoop direction and varied from a maximum at the top and bottom of the pipe that had the highest bending stresses to zero at the neutral axis. Though ratcheting occurred primarily in the hoop direction, some ratcheting in the axial direction was observed in 304 stainless steel pipe in both static and dynamic tests. Axial ratcheting was insignificant in the carbon steel pipe. Data obtained from these tests are presented. Measured ratcheting strains are compared to approximations of Beaney, Edmunds and Beer and to finite element computations.

Corrosion of Stainless Steel for HLW Containers Under Gamma Irradiation

1992 ◽  
Vol 294 ◽  
Author(s):  
K. Osada ◽  
S. Muraoka
Keyword(s):  
Stainless Steel ◽  
Radioactive Waste ◽  
Gamma Irradiation ◽  
Pitting Corrosion ◽  
Electrochemical Method ◽  
Fission Products ◽  
304 Stainless Steel ◽  
Redox Potentials ◽  
High Level Radioactive Waste ◽  
High Level

ABSTRACTThe corrosion behavior of type 304 stainless steel was studied under gamma irradiation as part of the evaluation for the long-term durability of high-level radioactive waste (HLW) disposal containers. Gamma rays, generated from fission products in high-level radioactive waste, are considered to change the environment around the canisters and overpacks. The redox potentials for NaCl solutions and corrosion potentials of stainless steel were measured to consider the effects of gamma irradiation, by using an electrochemical method. The pitting potentials of stainless steel for NaCl solutions were also measured to examine the pitting corrosion under gamma irradiation. As a result of this experiment, it is concluded that the oxidizing properties as a result of the formation of H2O2 and H2 produced by gamma irradiation depended on the concentration of Cl−, and that the strength of oxidizing properties of 1M (mol·dm−3) NaCl solution was particularly high. and the pitting corrosion was found for 1M NaCI solution under gamma irradiation at the dose rate of 2.6×102 C/kg·h (1.0×106 R/h) at 60°C, by using an electrochemical method.

Independent Quality Checking of UK Low Level Radioactive Waste for Plutonium Using the SCK•CEN Hexagon 2000 Passive Neutron Coincidence Counter

2003 ◽  
Author(s):  
R. May ◽  
R. Strange ◽  
M. Bruggeman ◽  
W. De Boeck
Keyword(s):  
Radioactive Waste ◽  
Cosmic Ray ◽  
Background Signal ◽  
Coincidence Counting ◽  
Low Level ◽  
Cosmic Ray Interactions ◽  
Coincidence Counter ◽  
Environment Agency ◽  
The Uk ◽  
Low Level Radioactive Waste

Checking low level wastes requires the detection of sub-milligram levels of plutonium. This is an extreme challenge for passive neutron coincidence counting as the levels of true signal are close to the background signal caused by cosmic ray interactions. The origin of cosmic-induced background is discussed. We describe the Hexagon 2000 passive neutron coincidence counter that has been designed and built for waste quality checking of low-level radioactive waste in the UK for the Environment Agency. The instrument uses computed neutron coincidence counting and improved filtering of high multiplicity cosmic-induced events. The instrument also correlates background signal with atmospheric pressure to further increase sensitivity. Preliminary measurements of background data and of test drums containing small amounts of plutonium are described.

scholarly journals Durable Concrete for a Waste Repository - Measurement of Ionic Ingress

1989 ◽  
Vol 176 ◽  
Author(s):  
R.F. Feldman ◽  
J.J. Beaudoin ◽  
K.E. Philipose
Keyword(s):  
Service Life ◽  
Radioactive Waste ◽  
Pore Structure ◽  
Research Program ◽  
Environmental Conditions ◽  
Low Level ◽  
Below Ground ◽  
Waste Repository ◽  
Low Level Radioactive Waste ◽  
Durability Of Concrete

ABSTRACTA waste repository for the below ground disposal of low level radioactive waste is planned at Chalk River Nuclear Laboratories. It relies greatly on the durability of concrete for the required 500 year service life. A research program to design durable concrete and predict its service life is in progress.The degradation of the concrete depends to a large extent on the rate of ingress of corrosive agents. Penetration of chloride and sulphate ions are particularly relevant. Twenty mix formulations were developed to create various types and qualities of concrete, and to study their behaviour in different site environmental conditions. A total of 1000 concrete specimens are being exposed at 20°C and 45°C to 25 different combinations of the corrosive agents including CO2. Procedures to measure the ionic profiles and to determine the factors controlling diffusion of the ions in the various concretes have been developed. Results of selected concrete systems exposed to chloride and sulphate solutions for 1 year are presented and discussed in terms of pore structure and permeability parameters of the concrete.

Experience in Progressing the Planning Application for New LLW Disposal Facilities for Dounreay

2008 ◽  
Vol 1107 ◽  
Author(s):  
David Broughton ◽  
Michael S Tait
Keyword(s):  
Radioactive Waste ◽  
Environment Protection ◽  
Protection Agency ◽  
High Quality ◽  
Stakeholder Consultation ◽  
The United Kingdom ◽  
Nuclear Decommissioning ◽  
Robust Planning ◽  
The Uk ◽  
Low Level Radioactive Waste

AbstractAn integral part of decommissioning the Nuclear Decommissioning Agency's (NDA) Dounreay site is the management of the solid low level radioactive waste (LLW). The United Kingdom Atomic Energy Authority (UKAEA) has developed and progressed a technical and stakeholder programme that has enabled it to submit a robust Planning Application to Highland Council (HC) for New LLW Disposal Facilities at Dounreay and to submit substantive preliminary safety and environmental cases to the Nuclear Installations Inspectorate (NII) and the Scottish Environment Protection Agency (SEPA). To UKAEA’s knowledge this is the most advanced project in the UK for new LLW disposal facilities. Experience has been gained in progressing the Best Practicable Environmental Option (BPEO) Study, working with regulators in unfamiliar areas, and undertaking groundbreaking stakeholder consultation. Key lessons learnt are that stakeholders should be engaged in dialogue on the project as early as possible, documentation must be high quality and tailored to its audience, and internationally respected and credible consultants must be involved.

The Role of the National Low Level Waste Repository Operator in Delivering New Solutions for the Management of Low Level Wastes in the UK

2009 ◽  
Author(s):  
Martin Walkingshaw
Keyword(s):  
Radioactive Waste ◽  
Alternative Treatment ◽  
Parent Body ◽  
Low Level ◽  
The United Kingdom ◽  
Waste Repository ◽  
The Uk ◽  
The Village ◽  
Low Level Radioactive Waste

The UK National Low Level Waste Repository (LLWR) is located near to the village of Drigg in West Cumbria. It is the principal site for disposal of solid Low Level Radioactive Waste (LLW) in the United Kingdom. This paper describes the program of work currently being undertaken by the site’s operators, (LLW Repository Ltd and its newly appointed Parent Body Organisation), to extend the life of the LLWR and reduce the overall cost of LLW management to the UK taxpayer. The current focus of this program is to prevent disposal capacity being taken up at LLWR by waste types which lend themselves to alternative treatment and/or disposition routes. The chosen approach enables consignors to segregate LLW at source into formats which allow further treatment for volume reduction or, (for wastes with lower levels of activity), consignment in the future to alternative disposal facilities. Segregated waste services are incorporated into LLW Disposal commercial agreements between the LLWR operator and waste consignors.

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