The Effect of Chloride Concentration on Crevice Corrosion of some Welded Titanium Alloys

2008 ◽  
Vol 59 (2) ◽  
pp. 140-144
Author(s):  
Laurentiu Popa ◽  
Maria Radulescu ◽  
Alice Dinu ◽  
Lucian Velciu ◽  
Ioan Viorel Branzoi
Keyword(s):  
Waste Management ◽  
Titanium Alloys ◽  
Nuclear Waste ◽  
Crevice Corrosion ◽  
Chloride Concentration ◽  
Geological Disposal ◽  
Buffer Material ◽  
High Level Nuclear Waste ◽  
High Level

Geological disposal is identified by nearly all experts in the field of waste management as the only safe and sustainable option presently available, but the progress towards its implementation is slow. The nuclear waste must be safely storaged for hundreds of thousand years. Titanium alloys are some of the most promising candidates as container materials for the long-term disposal of high level nuclear waste (HLW) in rock salt formations. In the case of titanium waste containers, between the containers walls and the surrounding buffer material used to pack the disposal borehole some crevices can appear in the welded zone container/ shielding lid, under a biofilm etc. For this purpose we studied the effect of chloride concentration on crevice corrosion of some welded titanium alloys (Grade 2 and Grade 12, respectively) in chloride solutions at 90oC by electrochemical methods (Ecorr vs time, potentiodynamic tests).

Repassivation Method to Predict Long Term Integrity of Low Alloy Titanium for Nuclear Waste Package

1990 ◽  
Vol 212 ◽  
Author(s):  
Shigeo Tsujikawa ◽  
Yoichi Kojima
Keyword(s):  
Nuclear Waste ◽  
Electrode Potential ◽  
Crevice Corrosion ◽  
Critical Conditions ◽  
Nacl Concentration ◽  
G 12 ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Alloy Titanium

ABSTRACTLong term corrosion resistance is evaluated for G-2 and G-12 titanium as a candidate of the high-level nuclear waste packages. The repassivation potential for crevice corrosion, ER, in comparison with the well known spontaneous potential, ESP, of a metal passivated in given environment, allows conclusions to be drawn whether it performs “permanent” or does not. This repassivation method is extended to determine critical conditions in terms of NaCl concentration and temperature for specimens kept at an electrode potential which is more noble than ER and is included in ESP ranges. Thus obtained NaCl concentration - temperature - crevice corrosion map could predict critical conditions for the titanium used in geologic formations.

Comparison of Granite, Tuff, and Basalt as Geologic Media for Long-Term Storage of High-Level Nuclear Waste

1990 ◽  
Vol 212 ◽  
Author(s):  
D. E. Grandstaff ◽  
V. J. Grassi ◽  
A. C. Lee ◽  
G. C. Ulmer
Keyword(s):  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
Long Term Storage ◽  
Hydrothermal Experiments ◽  
Ion Activity ◽  
Activity Ratios ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Term Storage

ABSTRACTSystematic differences in pH, cation/proton ion activity ratios, and redox have been observed between solutions produced in rock-water hydrothermal experiments with tuff, granite, and basalt. Stable pH values in tuff-water experiments may be as much as 1.5 pH units more acidic than basalt-water experiments at the same temperature and ionic strength. Redox (log fO2) values in 300°C tuff experiments are 4–7 orders of magnitude more oxidizing than basalt experiments and ca. 4 log units more oxidizing than the magnetite-hematite buffer. Such fluid differences could significantly affect the performance of a high-level nuclear waste repository and should be considered in repository design and siting.

scholarly journals A Critical Review of the Recent Improvements in Minimizing Nuclear Waste by Innovative Gas-Cooled Reactors

2008 ◽  
Vol 2008 ◽  
pp. 1-18 ◽  
Author(s):  
E. Bomboni ◽  
N. Cerullo ◽  
G. Lomonaco ◽  
V. Romanello
Keyword(s):  
Nuclear Waste ◽  
Critical Review ◽  
Simplified Models ◽  
Geological Disposal ◽  
Fuel Cycles ◽  
Multiple Recycling ◽  
High Level ◽  
Coupling Current ◽  
The University

This paper presents a critical review of the recent improvements in minimizing nuclear waste in terms of quantities, long-term activities, and radiotoxicities by innovative GCRs, with particular emphasis to the results obtained at the University of Pisa. Regarding these last items, in the frame of some EU projects (GCFR, PUMA, and RAPHAEL), we analyzed symbiotic fuel cycles coupling current LWRs with HTRs, finally closing the cycle by GCFRs. Particularly, we analyzed fertile-free and Pu-Th-based fuel in HTR: we improved plutonium exploitation also by optimizing Pu/Th ratios in the fuel loaded in an HTR. Then, we chose GCFRs to burn residual MA. We have started the calculations on simplified models, but we ended them using more “realistic” models of the reactors. In addition, we have added the GCFR multiple recycling option usingkeffcalculations for all the reactors. As a conclusion, we can state that, coupling HTR with GCFR, the geological disposal issues concerning high-level radiotoxicity of MA can be considerably reduced.

scholarly journals Effects of long-term exposure of tuffs to high-level nuclear waste repository conditions. Final report

10.2172/59938 ◽  
1986 ◽  
Author(s):  
J.D. Blacic ◽  
D.T. Vaniman ◽  
D.L. Bish ◽  
C.J. Duffy ◽  
R.C. Gooley
Keyword(s):  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
Final Report ◽  
High Level Nuclear Waste ◽  
Waste Repository ◽  
High Level

An Overview of Nuclear Waste Management

1983 ◽  
Vol 2 (1) ◽  
pp. 41-56
Author(s):  
L. W. Shemilt ◽  
G. Sheng
Keyword(s):  
Waste Management ◽  
Nuclear Waste ◽  
Fission Products ◽  
Nuclear Fission ◽  
Technical Problems ◽  
Site Investigations ◽  
Geochemical Properties ◽  
International Projects ◽  
High Level

The disposal and safe handling of high-level radioactive wastes resulting from the generation of electricity by nuclear fission is a topic of great current concern and future importance. All types of nuclear fuel produce similar quantities of fission products per GW over time, and the most important factor in handling is whether the waste is used fuel or reprocessing waste. It is believed that deep terrestrial or sub-seabed disposal offer the most risk-free options, the former being the more immediate proposition. Developments in media for encapsulating reprocessed wastes may increase the ease with which they can be disposed of. All geologic systems of disposal require a multi-barrier approach, but there are no significant technical problems to safe disposal in this way. Site investigations must study geologic formations, hydrogeology, geochemical properties of host rock and groundwater and long-term stability of the site. Risk assessment of the long-term safety of disposal sites is necessarily probabilistic, and is the subject of much study. The major problem of such assessments is the lack of a commonly-accepted concept of ‘safe’ levels of radiation over geologic timescales. The paper examines in detail the Canadian waste management and research programs and discusses various international projects on nuclear waste disposal.

scholarly journals Transporting and Storing High-Level Nuclear Waste in the U.S.—Insights from a Mathematical Model

2019 ◽  
Vol 9 (12) ◽  
pp. 2437 ◽  
Author(s):  
Sebastian Wegel ◽  
Victoria Czempinski ◽  
Pao-Yu Oei ◽  
Ben Wealer
Keyword(s):  
Nuclear Waste ◽  
The United States ◽  
Nuclear Industry ◽  
High Level Waste ◽  
Geological Repository ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Interim Storage ◽  
Storage Facilities

The nuclear industry in the United States of America has accumulated about 70,000 metric tons of high-level nuclear waste over the past decades; at present, this waste is temporarily stored close to the nuclear power plants. The industry and the Department of Energy are now facing two related challenges: (i) will a permanent geological repository, e.g., Yucca Mountain, become available in the future, and if yes, when?; (ii) should the high-level waste be transported to interim storage facilities in the meantime, which may be safer and more cost economic? This paper presents a mathematical transportation model that evaluates the economic challenges and costs associated with different scenarios regarding the opening of a long-term geological repository. The model results suggest that any further delay in opening a long-term storage increases cost and consolidated interim storage facilities should be built now. We show that Yucca Mountain’s capacity is insufficient and additional storage is necessary. A sensitivity analysis for the reprocessing of high-level waste finds this uneconomic in all cases. This paper thus emphasizes the urgency of dealing with the high-level nuclear waste and informs the debate between the nuclear industry and policymakers on the basis of objective data and quantitative analysis.

International High Level Nuclear Waste Management

1974 ◽  
Vol 30 (1) ◽  
pp. 28-33
Author(s):  
Gisela Dreschhoff ◽  
D. F. Saunders ◽  
E. J. Zeller
Keyword(s):  
Waste Management ◽  
Nuclear Waste ◽  
Nuclear Waste Management ◽  
High Level Nuclear Waste ◽  
High Level
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