In Activity 36, Storing Waste, you evaluated Yucca Mountain,

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1 49 Comparing Site Risk TA L K I N G I T O V E R In Activity 36, Storing Waste, you evaluated Yucca Mountain, Nevada as a site for storing nuclear waste. The U.S. Congress considered several other sites before selecting Yucca Mountain. Today, there is still much controversy surrounding the selection of this site. Imagine that the year is 2015 and Congress is reconsidering its selection. Use what you have learned in this unit to help you evaluate two other sites that Congress first considered in the early 1980s. CHALLENGE Which site would you recommend for storing nuclear waste? MATERIALS For each student 1 completed Student Sheet 36.1, Analyzing Evidence: Yucca Mountain 1 completed Student Sheet 36.2, Discussion Web: Yucca Mountain 1 completed Student Sheet 44.2, Plate Boundaries 1 Student Sheet 49.1, Discussion Web: Comparing Site Risk D-57

2 Activity 49 Comparing Site Risk PROCEDURE 1. With your group, examine the earthquake and volcano risk maps below. These maps, produced by the U.S. Geological Survey, are based on the number of earthquakes and volcanoes that have occurred in each region. 2. Compare the risk of earthquakes and volcanoes in Deaf Smith County, Texas; ; and Yucca Mountain, Nevada. Discuss which site you think has the highest and lowest risk of each type of event. Remember to listen to and consider the ideas of the other members of your group. If you disagree with other members of your group, explain why you disagree. Earthquake Risk in the U.S. Relative risk level Very high High Moderate Slight Volcano Risk in the U.S. Relative risk level High Moderate D-58

3 Comparing Site Risk Activity Read additional information about the three sites on the following pages. Note: Most of your information on Yucca Mountain should come from Student Sheet 36.1, Analyzing Evidence: Yucca Mountain, and Student Sheet 36.2, Discussion Web: Yucca Mountain. 4. One half of your group will sort evidence related to Deaf Smith County, Texas while the other half of your group will sort evidence related to. Decide who will work on each site and use Student Sheet 49.1, Discussion Web: Comparing Site Risk, to sort the evidence for your site. Hint: Use Student Sheet 36.1 as well as the information on nuclear waste in Activity 36, Storing Waste, to help you evaluate the information. a. Write down information that you think supports storing nuclear waste at the site under the Yes column. b. Write down information that you think does not support storing nuclear waste at the site under the No column. 5. Present your work to the other half of your group, and listen carefully as they present their work to you. 6. Record any additional relevant evidence about the Yucca Mountain site on Student Sheet Use your knowledge of plate tectonics and the information presented in this unit to identify additional evidence that either supports or does not support storing waste at each of the three sites. Consider what you know about the structure of the earth, geological time, plate boundaries, the relative risk of natural disasters such as earthquakes and volcanoes, and what might happen to the earth s surface in the future. Hint: You may find it helpful to refer to information in your science notebook and to Student Sheet 44.2, Plate Boundaries. 8. With your group, discuss which of the three sites you think is the best for storing nuclear waste. Be sure to support your ideas with evidence. D-59

4 Activity 49 Comparing Site Risk Additional Information about Proposed Nuclear Waste Disposal Sites This county, in the northwest part of Texas (the panhandle ), has a total area of almost 4,000 km 2 (1,500 mi 2 ). In 2000, the population of the county was about 18,500, resulting in an average population density of about 5 people per km 2. The largest town, Hereford, is located in the southeast corner of the county and has a population of almost 15,000. One of the biggest industries in the county is agriculture. Deaf Smith County has one of the largest cattle populations in the state of Texas, with over 500,000 cows. The average annual rainfall is 44 cm (17 in). The minimum average temperature is 5 C (22 F) in January, and the average annual maximum is 34 C (93 F) in July. In the last 100 years, there were more than 100 earthquakes in Texas strong enough to be felt. Four of those earthquakes had a Richter magnitude of higher than Cattle in the Texas panhandle 5. An earthquake with a magnitude of about is predicted to occur in northwest part of Texas every years. There are no active volcanoes in Texas. Yucca Mountain is located in the southeastern part of Nye County, Nevada. It is the largest county in the state, with an area of about 47,000 km 2 (18,000 mi 2 ). In 2000, the population was about 32,500. D-60

5 Comparing Site Risk Activity 49 The federal government owns an area of approximately 1,450 km 2 (560 mi 2 ) known as Hanford, Washington. The towns of Richland, Pasco, and Kennewick, often referred to as the Tri-Cities, are approximately 40 km (25 mi) away. They have a combined population of about 125,000 people. The Columbia River Between 1870 and 1980, five earthquakes (of Richter magnitude 5 or higher) occurred in the area. The largest and most recent occurred on July 16, 1936 and registered a magnitude of 5.8. On average, the area receives 20 cm (8 in) of rain each year. Temperatures range from as low as 12 C (10 F) in the winter to as high as 43 C (110 F) in the summer. The Columbia River flows through the middle of the site. The Columbia River is the largest river in the upper northwestern United States, and it releases more water into the Pacific Ocean than any other river in North or South America. Over 160 kilometers (100 miles) away, along the western coast of Washington state, there is a mountain range called the Cascades that is made up of active, dormant, and extinct volcanoes. ANALYSIS 1. Aside from earthquakes and volcanoes, what other risks might you want to consider when selecting a site for storing nuclear waste? 2. Where do you think the nuclear waste should be stored: Deaf Smith County, Texas; ; or Yucca Mountain, Nevada? a. State your decision. b. Support your decision with as many pieces of evidence as you can. c. Discuss the trade-offs of your decision. 3. Reflection: Have your ideas about where to store nuclear waste changed during this unit? How? D-61