Deep Borehole Disposal of Plutonium

2008 ◽  
Vol 1107 ◽  
Author(s):  
Fergus G.F. Gibb ◽  
Kathleen J. Taylor ◽  
Boris E. Burakov
Keyword(s):  
High Pressure ◽  
Waste Management ◽  
Management Problem ◽  
Deep Borehole ◽  
Security Threat ◽  
High Pressure And Temperature ◽  
Geological Disposal ◽  
Waste Forms ◽  
Deep Boreholes

AbstractExcess plutonium not destined for burning as MOX or in Generation IV reactors is both a long-term waste management problem and a security threat. Immobilisation in mineral and ceramic-based waste forms for interim safe storage and eventual disposal is a widely proposed first step. The safest and most secure form of geological disposal for Pu yet suggested is in very deep boreholes and we propose here that the key to successful combination of these immobilisation and disposal concepts is the encapsulation of the waste form in small cylinders of recrystallized granite. The underlying science is discussed and the results of high pressure and temperature experiments on zircon, depleted UO2 and Ce-doped cubic zirconia enclosed in granitic melts are presented. The outcomes of these experiments demonstrate the viability of the proposed solution and that Pu could be successfully isolated from its environment for many millions of years.

Evaluation of the long-term behavior of potential plutonium waste forms in a geological repository

2014 ◽  
Vol 1665 ◽  
pp. 23-30 ◽  
Author(s):  
Guido Deissmann ◽  
Stefan Neumeier ◽  
Felix Brandt ◽  
Giuseppe Modolo ◽  
Dirk Bosbach
Keyword(s):  
Current Knowledge ◽  
Geological Disposal ◽  
Ceramic Waste ◽  
Corrosion Rates ◽  
Waste Forms ◽  
Safety Margins ◽  
Geological Repository ◽  
Closure Conditions ◽  
Long Term Behavior

ABSTRACTVarious candidate waste matrices such as nuclear waste glasses, ceramic waste forms and low-specification “storage” MOX have been considered within the current UK geological disposal program for the immobilization of separated civilian plutonium, in the case this material is declared as waste. A review and evaluation of the long-term performance of potential plutonium waste forms in a deep geological repository showed that (i) the current knowledge base on the behavior and durability of plutonium waste forms under post-closure conditions is relatively limited compared to HLW-glasses from reprocessing and spent nuclear fuels, and (ii) the relevant processes and factors that govern plutonium waste form corrosion, radionuclide release and total systems behavior in the repository environment are not yet fully understood in detail on a molecular level. Bounding values for the corrosion rates of potential plutonium waste forms under repository conditions were derived from available experimental data and analogue evidence, taking into account that the current UK disposal program is in a generic stage, i.e. no preferred host rock type or disposal concept has yet been selected. The derived expected corrosion rates for potential plutonium waste forms under conditions relevant for a UK geological disposal facility are in the range of 10-4 to 10-2 g m-2 d-1 and 10-5 to 10-4 g m-2 d-1 for borosilicate glasses, and generic ceramic waste forms, respectively, and ∼5·10-6 g m-2 d-1 for storage MOX. More realistic assessments of the long-term behavior of the waste forms under post-closure conditions would require additional systematic studies regarding the corrosion and leaching behavior under more realistic post-closure conditions, to explore the safety margins of the various potential waste forms and to build confidence in long-term safety assessments for geological disposal.

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).

Development of a Requirements Management System for Technical Decision-Making Processes in the Geological Disposal Project

2007 ◽  
Author(s):  
Hiroyoshi Ueda ◽  
Katsuhiko Ishiguro ◽  
Kazumi Kitayama ◽  
Kiyoshi Oyamada ◽  
Shoko Sato
Keyword(s):  
Decision Making ◽  
Waste Management ◽  
Nuclear Waste ◽  
Management System ◽  
Current Status ◽  
Nuclear Waste Management ◽  
Efficient Operation ◽  
Geological Disposal ◽  
Decision Making Processes

NUMO (Nuclear Waste Management Organization of Japan) has a responsibility for implementing geological disposal of vitrified HLW (High-Level radioactive Waste) in the Japanese nuclear waste management programme. Its staged siting procedure was initiated in 2002 by an open call for volunteer sites. Careful management strategy and methodology for the technical decision-making at every milestone are required to prepare for the volunteer site application and the site investigation stages after that. The formal Requirement Management System (RMS) is planned to support the computerized implementation of the specific management methodology, termed the NUMO Structured Approach (NSA). This planned RMS will help for comprehensive management of the decision-making processes in the geological disposal project, change management towards the anticipated project deviations, efficient project driving such as well-programmed R&D etc. and structured record-keeping regarding the past decisions, which leads to soundness of the project in terms of the long-term continuity. The system should have handling/management functions for the database including the decisions/requirements in the project in consideration, their associated information and the structures composed of them in every decision-making process. The information relating to the premises, boundary conditions and time plan of the project should also be prepared in the system. Effective user interface and efficient operation on the in-house network are necessary. As a living system for the long-term formal use, flexibility to updating is indispensable. In advance of the formal system development, two-year activity to develop the preliminary RMS was already started. The purpose of this preliminary system is to template the decision/requirement structure, prototype the decision making management and thus show the feasibility of the innovative RMS. The paper describes the current status of the development, focusing on the initial stage including work analysis/modeling and the system conceptualization.

scholarly journals Who Might Be Interested in a Deep Borehole Disposal Facility for Their Radioactive Waste?

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1542 ◽  
Author(s):  
Neil Chapman
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Management Programme ◽  
Radioactive Wastes ◽  
Deep Borehole ◽  
National Programme ◽  
Geological Disposal ◽  
Disposal Facility ◽  
Technical Issues

The deep borehole disposal (DBD) concept for certain types of radioactive wastes has been discussed for many decades, but has enjoyed limited R&D interest compared to ‘conventional’ geological disposal in an excavated repository at a few hundreds of metres depth. This article explores the circumstances under which a national waste management programme might wish to consider DBD. Starting with an assumption that further R&D will answer technical issues of DBD feasibility, it examines the types of waste that might be routed to borehole disposal and the strategic drivers that might make DBD attractive. The article concludes by identifying the types of national programme that might wish to pursue DBD further and the pre-requisites for them to give it serious consideration.

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