Investigation of Processing Parameters for the Consolidation of Actinide Glass-Ceramic Wasteforms by Hot Isostatic Pressing

MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4269-4274 ◽  
Author(s):  
Stephanie Thornber ◽  
Paul Heath ◽  
Ewan Maddrell ◽  
Martin C. Stennett ◽  
Neil C. Hyatt
Keyword(s):  
Sample Preparation ◽  
Hot Isostatic Pressing ◽  
Glass Ceramics ◽  
Processing Parameters ◽  
Isostatic Pressing ◽  
Al Content ◽  
High Temperature Heat Treatment ◽  
Nuclear Decommissioning ◽  
Optimum Formulation ◽  
The Uk

ABSTRACTGlass-ceramics were developed initially for the immobilization of miscellaneous Pu-residues at the UK’s Sellafield site from which it was uneconomic to recover Pu for reuse. Renewed interest in the immobilization of a portion of the UK PuO2 stockpile has led to glass-ceramics being evaluated for bulk Pu immobilization. The Nuclear Decommissioning Authority (NDA) in the UK have proposed hot isostatic pressing (HIP) as a potential consolidation technique for the processing of these wasteforms. In this study, zirconolite based glass-ceramics were investigated to determine an optimum formulation. The yield of zirconolite is shown to vary with glass composition and glass fraction, such that a higher Al content favours zirconolite formation. The sample preparation process is discussed to highlight the importance of a high temperature heat-treatment during sample preparation to achieve high quality HIPed wasteforms.

Pyrochlore glass‐ceramics fabricated via both sintering and hot isostatic pressing for minor actinide immobilization

2020 ◽  
Vol 103 (10) ◽  
pp. 5470-5479
Author(s):  
Yingjie Zhang ◽  
Zhaoming Zhang ◽  
Tao Wei ◽  
Linggen Kong ◽  
Young J. Kim ◽  
...  
Keyword(s):  
Hot Isostatic Pressing ◽  
Glass Ceramics ◽  
Minor Actinide ◽  
Isostatic Pressing

Microstructures and Properties of Cu–AISI304 Parts Fabricated by Improved Selective Laser Sintering

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Z. L. Lu ◽  
J. H. Liu ◽  
Y. S. Shi
Keyword(s):  
High Performance ◽  
Selective Laser Sintering ◽  
Hot Isostatic Pressing ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Cold Isostatic Pressing ◽  
Isostatic Pressing ◽  
Cu Content ◽  
Mechanical Performances ◽  
Liquid Sintering

For fabricating complex AISI304 parts with high performance by advanced powder/metallurgy technologies, cold isostatic pressing (CIP) is introduced into selective laser sintering (SLS) combined with hot isostatic pressing (HIP), which is abbreviated to selective laser sintering/isostatic pressed (SLS/IP). The effect of processing parameters on the densification of Cu–AISI304 parts is analyzed and then the influence of Cu on their relative densities, metallurgical structures, and mechanical performances are investigated. The results show that relative densities of Cu–AISI304 parts fabricated by SLS/IP are mainly influenced by CIP pressure and sintering temperature, and it is interesting to find that the formula 1−D=(1−D0)e−kP is testified by the CIP of SLS/IP. There is an antidensification phenomenon resulting from Cu and AISI304 in liquid sintering, but the relative densities of Cu–AISI304 parts can be gradually improved in HIP with Cu content increasing from 1 wt % to 3 wt %. After the above-mentioned Cu–AIS304 parts are finally hot isostatic pressed, their metallurgical structures consist of sosoloid (Cu,Ni) and (Fe,Ni) besides austenite (Fe,Cr,Ni,C), their best mechanical performances are close to those of solution treated compact AISI304 when Cu content is 3 wt %.

Hot Isostatic Pressing of Inconel 600 and 690 Powders for Pressure Retaining Components

2011 ◽  
Author(s):  
Timothy C. Jelfs ◽  
W. Barry Burdett
Keyword(s):  
Complex Geometry ◽  
Hot Isostatic Pressing ◽  
Cost Savings ◽  
Good Control ◽  
Processing Parameters ◽  
Metal Powders ◽  
Isostatic Pressing ◽  
Inconel 600 ◽  
Inconel Alloys ◽  
Inconel 690

Hot Isostatic Pressing (HIP) has been used for many years to consolidate porosity in cast metal shapes to improve mechanical properties. When applied to fine metal powders, it is possible to produce Near Net Shape (NNS) items and more complex geometry components that are fully dense and offer an attractive set of properties at reduced cost. NNS items produced from HIPed powder deliver cost savings by reducing initial material usage and subsequent machining costs. Powder production and HIP processing are automated methods, which provide protection against forging route obsolescence. Setup costs are lower and batch sizes are smaller, which makes HIPping particularly well suited to small numbers of high integrity components. HIPed powder microstructures are isotropic and equiaxed, with uniformly fine grain sizes not normally achieved in heavy section components, which facilitates ultrasonic NDE examination. Improved features to facilitate NDE are readily incorporated into the HIP assembly. Inclusion contents are lower and of more benign geometry, easing fracture assessment. In a broad program of testing, Rolls-Royce has established (1) that HIPed powder 316L/304L components, in items up to several tons in weight, have equivalent or slightly better strength, toughness and corrosion resistance than the wrought equivalents. Rolls-Royce are extending their activities to HIPing of Inconel alloys. The first phase has been to HIP test samples of Inconel 600 and Inconel 690 alloys. Initial testing has produced promising results in line with expectations of wrought material. There has also been the opportunity to vary the HIPing cycle to assess the effect of processing parameters on the final product. An ability to HIP Inconel components is thought to be of benefit in new plant construction, where material is often not readily available in required thick section. The adaptability and good control of the HIP technique also shows promise as a manufacturing route for future high temperature materials which will be required in Generation 4 civil builds.

Building Flexibility Into the Design of a Pilot Plant for the Immobilisation of Pu Containing Residues and Wastes

2013 ◽  
Author(s):  
C. R. Scales ◽  
E. R. Maddrell ◽  
J. Hobbs ◽  
R. Stephen ◽  
S. Moricca ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Pilot Plant ◽  
Hot Isostatic Pressing ◽  
Glass Ceramics ◽  
Size Reduction ◽  
Central Laboratory ◽  
Treatment Techniques ◽  
Mox Fuel ◽  
The Uk ◽  
Flowsheet Development

NNL and ANSTO on behalf of Sellafield Ltd have developed a process for the immobilisation of a range of Pu containing wastes and residues. Following the inactive demonstration of the technology the project is now focusing on the design of an active pilot plant capable of validating the technology and ultimately immobilising a waste inventory containing around 100kg plutonium. The diverse wastes from which it is uneconomic to recover Pu, require a flexible process with a wide product envelope capable of producing a wasteform suitable for disposal in a UK repository. Ceramics, glass ceramics and metal encapsulated wasteforms can be delivered by the process line which incorporates size reduction and heat treatment techniques with the aim of feeding a hot isostatic pressing process designed to deliver the highly durable wasteforms. Following a demonstration of feasibility, flowsheet development is progressing to support the design which has the aim of a fully flexible facility based in NNL’s Central Laboratory on the Sellafield site. Optimisation of the size reduction, mixing and blending operations is being carried out using UO2 as a surrogate for PuO2. This work is supporting the potential of using an enhanced glass ceramic formulation in place of the full ceramic with the aim of simplifying glove box operations. Heat treatment and subsequent HIPing strategies are being explored in order to eliminate any carbon from the feeds without increasing the valence state of the uranium present in some of the inventory which can result in an unwanted increase in wasteform volumes. The HIP and ancillary systems are being specifically designed to meet the requirements of the Sellafield site and within the constraints of the NNL Central Laboratory. The HIP is being configured to produce consolidated product cans consistent with the requirements of ongoing storage and disposal. With the aim of one cycle per day, the facility will deliver its mission of immobilising the identified waste and residues inventory within 3 years. During that period it will also be used to demonstrate the potential of this technology to deliver the immobilisation of a proportion of the UK plutonium stockpile that may not be suitable for use as MOx fuel should that decision be taken.

Investigation of Ce incorporation in zirconolite glass-ceramics for UK plutonium disposition

MRS Advances ◽  
2017 ◽  
Vol 2 (13) ◽  
pp. 699-704 ◽  
Author(s):  
Stephanie M. Thornber ◽  
Martin C. Stennett ◽  
Neil C. Hyatt
Keyword(s):  
Glass Ceramic ◽  
Perovskite Phase ◽  
Hot Isostatic Pressing ◽  
Glass Ceramics ◽  
Ceramic Phase ◽  
Isostatic Pressing ◽  
Preliminary Work

ABSTRACTCerium incorporation in zirconolite glass-ceramic systems, consolidated by hot isostatic pressing, was investigated. Samples were formulated to target Ce incorporation on the Ca and / or Zr sites. Results show successful incorporation of Ce into the ceramic phase although complete waste digestion was not achieved. The formation of a Ce-bearing perovskite phase when targeting Zr substitution, was associated with reduction of Ce4+to Ce3+. This study is part of preliminary work towards fabricating Pu-bearing glass-ceramic HIP samples.

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