Lesson 2 Plan

Yucca Mountain’s Natural Environment

Purpose:

This lesson introduces students to the geology and hydrology of Yucca Mountain and explains how the mountain’s natural features will help isolate nuclear waste in a repository.

Concepts:

1. The natural environment is important to repository safety.
   
   
2. To keep nuclear waste isolated in a repository for tens of thousands of years, we must limit the amount of water that could contact the waste.
   
   
3. Yucca Mountain has natural attributes that will help isolate nuclear waste in a repository.
   
   
4. A detailed understanding of Yucca Mountain’s natural environment is critical to assessing the repository’s safety over thousands of years.
   
   

Duration of Lesson:

One 50-minute class period

Objectives:

After participating in this lesson, students will be able to

1. Describe the geology of the Yucca Mountain site.
   
   
2. Identify the natural attributes that will help isolate nuclear waste in a repository at Yucca Mountain.
   
   
3. Describe how water moves within Yucca Mountain.
   
   
4. Discuss the likelihood of earthquakes and volcanoes affecting a repository at Yucca Mountain.

Skills:

Listing, describing, discussing, explaining, matching, reading, summarizing, working with maps

Vocabulary:

aquifer, basin, capillary force, chemistry, closed water basin, discharge area, evaporation, fault, fracture, geochemistry, geology, geologic repository, geophysics, Great Basin, groundwater, hydrology, igneous, non-welded tuff, magma, porosity, radionuclide, rock pore, saturated rock, seismic, seismograph, tuff, unsaturated rock, volcanism, volcanology, water molecule, water table, welded tuff, zeolite

Materials:

Drawing Materials

Reading Lesson: "Yucca Mountain’s Natural Environment"

Activity Sheet: "Rocks and Water at Yucca Mountain"

Transparency: “Natural System of Yucca Mountain”

Suggested Procedure:

1. Assign the reading lesson entitled “Yucca Mountain’s Natural Environment.” Allow approximately 15 minutes for reading.
   
   
2. Discuss the importance of keeping water away from nuclear waste in a repository. Also discuss the importance of understanding the geology and hydrology of Yucca Mountain for determining whether it can safely isolate nuclear waste.
   
   
3. Discuss and describe how Yucca Mountain was formed millions of years ago by deposits of volcanic ash. Also describe the mountain’s layers of volcanic tuff and the differences between “welded” and “non-welded” tuff.
   
   
4. Describe how water infiltrates the surface of Yucca Mountain; moves through the layers of rock to the water table; and how it moves laterally in the saturated zone, and eventually migrates into Amaragosa Valley and perhaps Death Valley. Also describe how the groundwater is contained in a closed basin and does not move into other groundwater systems.
   
   
5. Ask students to draw a cut-away sketch of Yucca Mountain, indicating 1) the underground location of the repository, 2) the natural features that will limit the amount of water that could reach the waste in the repository, and 3) the natural features that would restrict the movement of radioactive particles from the repository.
   
   
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   The natural features include:
   
   
   • Dry climate
     
   • Surface soils and terrain
   • Rock above the repository
   • Rock fractures
   • Rock below repository
   • Deep water table
   • Closed water basin
     
     
   Also have students indicate the following approximate distances on their sketch:
   
   
   • Surface to underground repository ~300 meters
   • Repository to water table ~300 meters
   • Yucca Mountain to Amaragosa Valley ~20 kilometers
     
     
6. After students have finished their sketches, you may choose a few students to show their work to the rest of the class. Ask them to describe how each feature contributes to isolating nuclear waste and protecting people and the environment.
   
   Note: As an alternative to step six above, you may choose to show the transparency entitled, “Natural System of Yucca Mountain” and engage students in a discussion about how each feature potentially contributes to isolating nuclear waste and protecting the environment.
   
   
7. If time allows, go over the instructions for the activity sheet entitled “Rocks and Water at Yucca Mountain” and give students about 10 minutes to answer the questions. If time is out, assign the activity sheet as homework.
   
   
8. For extra credit, ask students to report to the classon information about the reason for the stretching of the earth’s surface that has created, and is still creating, the Basin & Range Province. The students should discuss plate tectonics and explain the characteristic north-south trending ranges, volcanism, and seismicity of the Basin & Range Province. The students should relate the crustal extension in the Yucca Mountain area to volcanism and earthquakes.

Teacher Evaluation of Student Performance:

Completion of Yucca Mountain sketch and activity sheet and participation in class discussion will indicate understanding.