scholarly journals Using hot isostatic pressing for radioactive waste isolation purposes

2021 ◽  
Vol 16 (3) ◽  
pp. 20-29
Author(s):  
Yu. A. Pokhitonov ◽  
◽  
V. A. Starchenko ◽  
I. Yu. Dalyaev ◽  
S. L. Titov ◽  
...  
Keyword(s):  
High Performance ◽  
Metallic Copper ◽  
Hot Isostatic Pressing ◽  
Equipment Management ◽  
Khlopin Radium Institute ◽  
Radium Institute ◽  
Industrial Facilities ◽  
Isostatic Pressing ◽  
Remote Maintenance ◽  
And Control

The paper summarizes the findings of a study focused on hot isostatic pressing (HIP) technique implemented by the Khlopin Radium institute. The equipment was designed and manufactured at the Kharkov’s Physics and Technology Institute. The installation provided a pressure of up to 400 NPa with the pressing temperature of up to 1250°C. The experiments were carried out on installations located in hot cells in the radiochemical department (Gatchina city). Samples of materials for HLW immobilization (titanate ceramics of the synroc type, stabilized cubic zirconia) and matrices for 129I immobilization based on copper iodide and metallic copper were obtained. The leaching rate from these samples of HLW elements (simulators) amounted to (0.5—1.5)·10–9 g/(cm2 ·day). Despite the high-performance characteristics of the materials obtained, some problems were revealed associated with the remote maintenance of equipment and the lack of industrial design analogues. Considering the experience gained, we believe that fairly simple equipment can be designed implying no complex systems and providing minimum preparatory operations. Joint efforts of technologists and designers will enable the automatization of equipment management and control through local control systems. Material loading and unloading operations can be robotized as well. Such technical solutions are expected to be in demand at industrial facilities for HLW final disposal (or when handling damaged fuel during the decommissioning of radiation and nuclear hazardous facilities).

Synthesis of Crystalline Ceramics for Actinide Immobilisation

2007 ◽  
Author(s):  
B. Burakov ◽  
V. Gribova ◽  
A. Kitsay ◽  
M. Ojovan ◽  
N. C. Hyatt ◽  
...  
Keyword(s):  
Hot Isostatic Pressing ◽  
Industrial Applications ◽  
Nuclear Industry ◽  
Synthesis Methods ◽  
Khlopin Radium Institute ◽  
Radium Institute ◽  
Joint Project ◽  
Ceramic Synthesis ◽  
The Matrix ◽  
Processing Plants

Methods for the synthesis of ceramic wasteforms for the immobilization of actinides are common to those for non-radioactive ceramics: hot uniaxial pressing (HUP); hot isostatic pressing (HIP); cold pressing followed by sintering; melting (for some specific ceramics, such as garnet/perovskite composites). Synthesis of ceramics doped with radionuclides is characterized with some important considerations: all the radionuclides should be incorporated into crystalline structure of durable host-phases in the form of solid solutions and no separate phases of radionuclides should be present in the matrix of final ceramic wasteform; all procedures of starting precursor preparation and ceramic synthesis should follow safety requirements of nuclear industry. Synthesis methods that avoid the use of very high temperatures and pressures and are easily accomplished within the environment of a glove-box or hot cell are preferable. Knowledge transfer between the V. G. Khlopin Radium Institute (KRI, Russia) and Immobilisation Science Laboratory (ISL, UK) was facilitated in the framework of a joint project supported by UK Royal Society. In order to introduce methods of precursor preparation and ceramic synthesis we selected well-known procedures readily deployable in radiochemical processing plants. We accounted that training should include main types of ceramic wasteforms which are currently discussed for industrial applications.

Freeform Fabrication of High Performance Titanium Components via SLS/HIP

1998 ◽  
Vol 542 ◽  
Author(s):  
S. Das ◽  
J. J. Beaman ◽  
M. Wohlert ◽  
D. L. Bourell
Keyword(s):  
High Performance ◽  
Selective Laser Sintering ◽  
Hot Isostatic Pressing ◽  
Laser Sintering ◽  
Single Step ◽  
Isostatic Pressing ◽  
Freeform Fabrication ◽  
Post Process ◽  
Processed Material ◽  
Full Densification

AbstractThis paper presents the development of Selective Laser Sintering/Hot Isostatic Pressing (SLS/HIP) technology for production of functional high performance components in the titanium alloy Ti-6AI-4V. SLS/HIP is a net shape manufacturing technique that combines and exploits the freeform shaping capability of selective laser sintering and the full densification capability of hot isostatic pressing. The advantages of SLS combined with in situ HIP encapsulation include single step net shape canning, full densification by containerless HIP, no container-powder adverse interactions, reduced pre-processing time, and minimal post-process machining compared to conventional HIP of canned powders. Microstructure and mechanical properties of SLS processed and HIP post-processed Ti-6A1-4V are consistent with conventionally processed material. The potential of SLS/HIP technology was demonstrated by net shape fabricating a component to specification, namely the titanium guidance section housing base for the AIM-9 Sidewinder missile.

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 %.

A Novel Forming Process for Powder Metallurgy of Superalloys

2014 ◽  
Vol 622-623 ◽  
pp. 833-839 ◽  
Author(s):  
Qian Bai ◽  
Jian Guo Lin ◽  
Gao Feng Tian ◽  
Daniel S. Balint ◽  
Jin Wen Zou
Keyword(s):  
Powder Metallurgy ◽  
Relative Density ◽  
High Performance ◽  
Low Cost ◽  
Hot Isostatic Pressing ◽  
Hot Extrusion ◽  
Forming Process ◽  
Isostatic Pressing ◽  
Wide Range ◽  
Forming Temperature

Powder metallurgy (PM) of nickel-based superalloys has been used for a wide range of products owing to their excellent special properties in processing and applications. Typical processes for high performance PM superalloys include hot isostatic pressing, hot extrusion and hot isothermal forging. Hot isostatic pressing is normally conducted at a high temperature, by using a low pressure for a long time in a closed vessel, resulting in high cost and low product efficiency. In this paper a novel forming process, i.e. direct powder forging for powder metallurgy of superalloys has been proposed. In this process, the encapsulated and vacuumed powder is heated up to the forming temperature and forged directly to the final shape, by using a high forming load for a very short time. Direct powder forging is a low-cost and energy-saving process compared to conventional PM processes, and in addition, press machines of conventional forging can be used for direct powder forming process. In direct powder forging it is important to control the relative density of the deformed part since the existence of voids could reduce the mechanical strength and fatigue life. In this paper, feasibility tests of direct powder forging are presented. Microstructure, relative density and hardness of the formed specimen were studied.

scholarly journals Mechanical Properties of Powder Metallugry (Ti-6Al-4V) with Hot Isostatic Pressing

2020 ◽  
Vol 10 (3) ◽  
pp. 5637-5642
Author(s):  
M. A. Elfghi ◽  
M. Gunay
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Performance Optimization ◽  
High Performance ◽  
Hot Isostatic Pressing ◽  
Two Phase ◽  
Manufacturing Defects ◽  
Isostatic Pressing ◽  
Different Temperatures ◽  
The Impact

Titanium alloys are widely used due to their high performance and low density in comparison with iron-based alloys. Their applications extend to aerospace and military in order to utilize their high resistance for corrosion. Understanding the mechanical properties and microstructure of titanium alloys is critical for performance optimization, as well as their implications on strength, plasticity, and fatigue. Ti-6Al-4V is an α+β two-phase alloy and is considered one of the most commonly used titanium alloys for weight reduction and high-performance. To avoid manufacturing defects, such as porosity and composition segregation, Hot Isostatic Pressing (HIP) is used to consolidate alloy powder. The HIP method is also used to facilitate the manufacturing of complex structures that cannot be made with forging and casting. In the current research, Ti-6Al-4V alloys were manufactured with HIP and the impact on heat treatment under different temperatures and sintering durations on the performance and microstructure of the alloy was studied. The results show changes in mechanical properties and microstructure with the increase of temperature and duration.

Study of Glass Ceramic Diffusion During Hot Isostatic Pressing of Encapsulated PZT Ceramics

1991 ◽  
Vol 251 ◽  
Author(s):  
A. Leriche ◽  
P. Aleksandrowicz ◽  
B. Thierry
Keyword(s):  
Glass Ceramic ◽  
High Performance ◽  
Complex Shape ◽  
Hot Isostatic Pressing ◽  
Pzt Ceramics ◽  
Isostatic Pressing ◽  
Ceramic Samples ◽  
Diffusion Phenomena ◽  
Encapsulation Method ◽  
Dielectric Ceramics

ABSTRACTThe development of high performance piezoelectric and dielectric ceramics needs a close control of density and microstructure. Hot isostatic pressing technique using glass encapsulation method allows to produce dense and complex shape ceramics with controlled grain size. However, diffusion phenomena occur at glass ceramic interface during HIP treatment.In this study, the glass diffusion into PZT ceramics was examined for different glass types. We noted silicon species diffusion into ceramic and also lead migration into glass resulting from PZT decomposition.HIP carried out with diffusion barrier surrounding ceramic samples allows to prevent such a diffusion.

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