Science and Technology for Environmental Cleanup at Hanford (2001) / Chapter Skim
Currently Skimming:
4 System Assessment Capability
4 System Assessment Capability
Pages 51-65
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 51... ...
These products include mass balances of inventories and contaminant releases' to be provided by the Inventory Technical Element (Chapter 5~; conceptual models, numerical models, and parameter databases for contaminant fate and transport to be provided by the Vadose Zone, Grounclwater, and River Technical Elements (Chapters 6-8~; and human, ecological, economic, and cultural impact data to be provicled by the Risk Technical Element (Chapter 9~. Given the importance of the S&T program to the SAC, the committee provides a short review and assessment of the SAC in this chapter to set the stage for more detailed assessments of the S&T technical elements later in this report.
|
From page 53... ...
SAC Rev. 0 is intended to be a proof-of-principle implementation.
|
From page 54... ...
O assessment. This number will probably increase to 500 before this assessment is completed (Mark Freshley, Pacific Northwest National Laboratory, written communication, April 12, 2001~.
|
From page 55... ...
55 o at: o In a)
|
From page 56... ...
56 St _ e: 8 Cat .
|
From page 58... ...
ce IL I E Y ~ ·' ° o E a' ~n c~ ~ ~ 3 |
From page 59... ...
59 In = = E = N = E ·' S E 9 To E E e e E A, ~ ~8 it, , - tie it <,, a)
|
From page 60... ...
- o ,Q Cut CO a' a' lL 0 ~ ~ ~ a)
|
From page 61... ...
61 - ~ ~ c a~ ~s "c ~ ~ ~n E ~— ~ C~ 3 e~ tl5 C ~ Q ._ _ ~ Y ~ .% —O ~ .o O ~ O ~ O ~ 3 cn O Q ' a E ~ o ~ ~, E Q Q ~i cn a)
|
From page 62... ...
For example, technetium-99, iodine-129, and uranium-238 have half-lives of 0.2 million, 16 million, and 4.5 billion years, respectively. If peak risk occurs beyond 1,000 years, then other model assumptions, particularly the assumption that climate remains unchanged, may not be realistic.
|
From page 63... ...
Relatively few data sets are available on contaminant distributions, concentrations, and speciation in the unsaturated zone deeper than 20 to 30 meters (Mark Freshley, Pacific Northwest National Laboratory, written communication, September 6-8, 2000; Myers and Gee, 2000~. In addition, the lateral extent of contaminants beyond the "footprints" of waste disposal sites, such as tanks, cribs, and trenches, is poorly known.
|
From page 64... ...
The Hanford Site is a fire-prone ecosystem,6 as evidenced by range fires in 1984 and 2000 each of which burned about half of the area , of the site.' Fire represents a potentially important agent for mobilizing contaminants contained in vegetation and near-surface soils. Radionuclides contained in the burned vegetation can be released directly into the atmosphere, and near-surface contaminants could be mobilized by increased infiltration or surface erosion accompanying the loss of vegetation.
|
From page 65... ...
The committee believes that S&T can play a central role in reducing uncertainty—for example, through the collection _ of data on current contaminant conditions at the site and the development or adaptation of procedures to validate SAC predictions. This S&T work must be conducted concurrently with SAC development, so that results from current versions of SAC can be interpreted properly and S&T results can be incorporated into future revisions.
|
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.