Waste Forms Technology and Performance Final Report (2011) / Chapter Skim
Currently Skimming:
1 Findings and Recommendations
1 Findings and Recommendations
Pages 3-14
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 3... ...
from making "recommendations on applications of particular production methods or waste forms to specific EM waste streams." Although the committee has not made recommendations on specific applications, it has identified potential opportunities for applying waste forms and production methods to DOE-EM waste streams. The committee has focused on waste forms and production methods for highlevel radioactive waste (HLW)
|
From page 4... ...
Waste forms perform optimally in a disposal environment when they are matched with the appropriate physical and chemical conditions that foster longterm stability. An important implication of this fact is that the suitability of a waste form for disposal depends crucially on the characteristics of the disposal facility into which it will be emplaced.
|
From page 5... ...
The lack of waste form performance requirements gives DOE flexibility in selecting waste forms for immobilization and disposal of waste in con 2 This office was being subsumed into DOE's Office of Nuclear Energy when the present report was being finalized.
|
From page 6... ...
The absence of specific waste form performance requirements means that a risk-informed, adaptive repository program should readily accommodate new waste forms through the itera
|
From page 7... ...
In the case where the calculated releases from a disposal system meet safety criteria because of radioelement solubility limits, then the motivation for developing advanced waste forms would be based more on factors such as waste loading and ease of processing rather than durability. FINDING ON STUDY CHARGE 3 Identify and describe state-of-the-art tests and models of waste forms used to predict their performance for time periods appropriate to their disposal system.
|
From page 8... ...
Many of the current models that are being used in the United States to model waste form behavior in disposal systems are based on ad hoc simplifications specific to the proposed repository at Yucca Mountain, Nevada. Other national programs have developed a substantial capability for modeling the long-term behavior of some types of waste forms based on fundamental principles; for example, the GLAMOR program in Europe is a cooperative effort of several researchers, including researchers from the United States, to elucidate the mechanisms controlling long-term durability of vitrified high-level waste.
|
From page 9... ...
In addition, study of relevant natural analogue materials, where available, could also provide additional lines of evidence and arguments to increase confidence in waste form performance over 103-106 year time scales. FINDING ON STUDY CHARGE 4 Identify and describe potential modifications of waste form production methods that may lead to more efficient production of waste forms that meet their performance requirements.
|
From page 10... ...
Consequently, DOE-EM would benefit from having a "toolbox" of waste forms available for different waste streams and disposal environments. However, compatibility of the waste form with its intended disposal environment is not the only important consideration when making a selection decision, as explained in the following overarching finding.
|
From page 11... ...
Borosilicate glass waste forms are durable in many, but certainly not all, disposal environments. Disposal of borosilicate glass in an environment that is under saturated in silica, for instance, could result in accelerated degrada tion and release of technetium-99.
|
From page 12... ...
DOE-EM is also building facilities to process and immobilize HLW at the Hanford Site in Washington. As the cleanup program continues DOE-EM will have opportunities to incorporate emerging developments in science and technology on waste forms and waste form production technologies into its baseline approaches.
|
From page 13... ...
In short, scientific advances, both now and in the future, offer the potential for more effective solutions to DOE-EM's waste management challenges. OVERARCHING RECOMMENDATION: DOE-EM should enhance its capabilities for identifying, developing where appropriate, and utiliz ing state-of-the-art science and technology on waste forms, waste form production processes, and waste form performance.
|
From page 14... ...
. The Office of Nuclear Energy sponsors a fuel cycle R&D program.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.