f
e
e
t
Storage
Container
Ramp to tunnels
Processing site
Cross-section
of tunnels
Water table
1
2
3
4
low-level waste so they can make mutually ben-
efcial arrangements. A state that is more will-
ing than its neighbors to accept a waste disposal
facility can negotiate with other states willing to
pay for the beneft of using radioactive materials
without having to build and operate their own
waste facilities.
Transuranic waste contains chemicals above
uranium in the periodic table and is produced
as a by-product of plutonium processing by the
defense industry and the national laboratories.
Transuranic waste is usually stored on-site in
drums or casks temporarily and then shipped
to the DOE-operated Waste Isolation Pilot Plant
(WIPP) near Carlsbad, New Mexico. WIPP,
which began operation in 1999, is the frst per-
manent geologic depository in the world and
has been certifed by the EPA as being capable
of isolating transuranic wastes from the envi-
ronment for at least 10,000 years (see www.wipp.
energy.gov).
High-level radioactive waste is composed of
spent nuclear fuel rods and other materials that
have high radioactivity levels and long half-lives.
Tese materials are typically produced by nuclear
reactors, but they are also produced by nuclear
Iigure 7. Proposed Storage at Yucca Mountain
Source: U.S. Nuclear Regulatory Commission; www.nrc.gov/waste/hlw-disposal/design.html.
NationaI Science 7eachers Association 12
fuel reprocessing in defense-related activities. Te
defense-related materials are sent to WIPP. Te
civilian high-level waste does not have a deposi-
tory site at this writing. Nuclear fuel rods that have
been removed from fssion reactors are stored on-
site, either in deep pools of water—which serve as
radiation absorbers—or in concrete and steel casks
cooled by air convection.
Spent Nuclear Fuel
Most American nuclear reactors—both civil-
ian and military—are fueled by uranium that
is packed into tubes and wrapped together in a
square 15' by 15' bundle (Kane 2002). Te tubes
spend approximately two years inside a working
reactor, by which time the uranium has given up
its useful energy and has been transformed into
other highly radioactive elements (Andrews
2006). Te bundles of SNF are removed from
the reactor by cranes and placed in deep pools of
water at the reactor site. Te water absorbs both
the radiation emitted and the heat given of by
the radioactive decay of the materials within the
tubes. Te materials will continue to be highly
radioactive for a period of tens of years to tens
of thousands of years.
By the 1980s, cooling pools at many of the
older nuclear facilities were becoming crowded
with fuel rod bundles (U.S. Nuclear Regulatory
Commission [NRC] 2003). Rather than build
additional pools, the NRC and DOE permitted
Iigure 8. Proposed RaiI 7ransport of IueI Rods in Yucca Mountain
Source: Image courtesy of the U.S. Department of Energy; Ofce of Civilian Radioactive Waste Management.
Radioactive Waste: Resources for Environmental Literacy
13
utilities to store the older fuel rod bundles—which
have lost much of their radioactivity and heat—in
concrete and steel casks that are air-cooled and sit
in the open on the reactor site (see Figure 6).
Te federal government had promised the
American electric power generation industry as
early as 1957 that it would open a storage facil-
ity to which all the SNF and other high-level ra-
dioactive waste from around the United States
would be shipped and safely stored for 10,000
years. It was estimated in 2005 that commercial
nuclear power plants had 53,440 metric tons
of SNF, which is projected to grow to 119,000
metric tons by 2035 (see www.ocrwm.doe.gov/
ym_repository/about_project/waste_explained/
howmuch.shtml).
The Yucca Mountain Nuclear Repository
In 1982 the U.S. Congress passed the Nuclear
Waste Policy Act, which authorized DOE to
begin examining potential sites for the lo-
cation of a high-level waste nuclear reposi-
tory (see www.ocrwm.doe.gov/ym_repository/
about_project/nwpa.shtml). By 1983, DOE had
identified nine possible sites and had begun
to examine the geology, hydrology, seismic
activity, volcanic setting, ecology, climate, and
meteorology surrounding each site. In 1987
Congress amended the Nuclear Waste Policy
Act to direct DOE to study only Yucca Moun-
tain, Nevada, and in 2002 Congress and Presi-
dent George W. Bush approved Yucca Moun-
tain as the site for constructing a high-level
radioactive nuclear waste depository for the
long-term storage of spent fuel rods and other
high-level waste (see Figure 7). Development
of this site has been many years in planning
but has been held up in the court system by
lawsuits that may take years to settle.
Yucca Mountain is located about 100 miles
northwest of Las Vegas, within the Nellis Air
Force target range and adjacent to the Nevada
nuclear test site, where a number of under-
ground nuclear explosions have been conducted
(see www.ocrwm.doe.gov/info_library/news-
room/photos/photos_maps.shtml). Te plan is
to dig a cave under Yucca Mountain with two
access shafs for the delivery of SNF. Tere will
be at least 52 emplacement tunnels 18 feet in
diameter (35 miles total length) within the cave
where the SNF and other high-level nuclear
wastes will be deposited in casks to rest for at
least 10,000 years (Kane 2002). Te placement of
the casks in the tunnels will be by remote-con-
trolled railroad-style cars running along tracks
(see Figure 8).
One major problem that scientists fore-
see for the repository is the potential pen-
etration of rainwater into the caves. With-
out proper design, rainwater could dissolve
radioactive materials within the fuel bun-
dles and carry them into the groundwater
beneath Yucca Mountain. To prevent this
scenario from occurring, the storage tun-
nels are expected to be lined with steel, the
casks covered with plastic drip shields, and
the casks themselves will have outer clad-
ding that is particularly resistant to chemi-
cal reactions with water.
Essential Question 7:
How Can Radioactive Waste Be Moved
Safely to a Storage Facility, and What
Are the Risks Associated With the
Different Transport Options?
Moving SNF from nuclear reactors to the Yucca
Mountain repository will involve trains, trucks,
or a combination of the two. Both pose signif-
cant challenges that involve the type of transport
and the means of containment (casks).
NationaI Science 7eachers Association 14
Trains
As many as 32 locations that currently store
high-level wastes—including SNF—have no rail
links; therefore, those locations could not send
materials to the Yucca Mountain repository by
rail. Furthermore, there is currently no rail link
from the existing rail lines to Yucca Mountain.
DOE has identifed fve possible rail routes from
existing rail lines to Yucca Mountain, spanning
100 to 360 miles (DOE Ofce of Civilian Ra-
dioactive Waste Management 2002). However,
building a new rail route to Yucca Mountain in-
volves a variety of challenges, including conficts
over land use, adverse environmental impacts,
and the potential for lengthy litigation. Te esti-
mated cost of constructing any of the fve routes
could exceed $1 billion; estimates for the Cali-
ente route favored by DOE currently approach
$2 billion (Associated Press 2007).
Critical accidents could also cripple possible
rail transportation of SNF. Based on an analysis
done in 2001 using a hypothetical rail tunnel fre
involving SNF in Baltimore, Maryland, it is esti-
mated that a critical accident could contaminate
32 square miles of land and result in 4,000 to
28,000 latent cancer fatalities over the course of
50 years (Lamb and Resnikof 2001).
Trucks
Legal-weight trucks can move SNF from all
current repositories to the Yucca Mountain re-
pository. DOE has designated that most of these
truck shipments will occur over the Interstate 80
corridor. It would require approximately 109,000
truck shipments—approximately 8 shipments
per day—between 2010 and 2048 to move the
volume of SNF currently stored on-site by civil-
ian and defense-related operations (Dilger and
Halstead 2005). However, at current stafng
levels, Nevada could only handle about 2 ship-
ments per day.
With no accidents, the state of Nevada es-
timates that radiation exposure rates will be
approximately 10 mrem/h from a distance of
2 m from the cask transporting the SNF (Hal-
stead 2002). This would translate to an expo-
sure rate between 2,000 and 8,000 mrem/y for
truck safety inspectors, exceeding the expo-
sure limit established by the EPA. Therefore,
the state of Nevada would have to spread the
inspection jobs among more people—hiring
more truck inspectors—so that the dose per
person would decrease.
Te efects of potential truck accidents are
more difcult to estimate. Several questions
would need to be answered: Will the containing
cask be breached? How many people live within
1 mile of the accident site? How much—and
what type—of radiation would be released? Te
state of Nevada estimates that, based on previ-
ous accident rates in shipping SNF, the number
of accidents in shipping SNF to Yucca Mountain
would be 160–190 over the course of 38 years—
approximately 4.2–5.0 accidents each year (Hal-
stead 2002).
Casks
Any cask that will carry nuclear waste must pass
a series of puncture, fre, and impact tests in or-
der to be certifed by the NRC (DOE Ofce of
Civilian Radioactive Waste Management 2006).
Te tests include
surviving a 9 m drop onto an unyielding
surface,
surviving a puncture test entailing a 1 m
drop onto a steel rod 16 cm in diameter,
surviving 30 minutes in an all-engulfng
800°C fre,
surviving immersion in 0.9 m of water, and
surviving a one-hour immersion under 200 m
of water.
•
•
•
•
•
Radioactive Waste: Resources for Environmental Literacy
15
Typicalspecifcations:grossweight(includingfuel)250,000pounds(125tons);cask
diameter8feet;overalldiameter(includingimpactlimiters)11feet;overalllength
(includingimpactlimiters)25feet;capacityupto26PWRor61BWRfuelassemblies.
Iigure 9. 7ypicaI Spent IueI 7ransportation Casks
Source: U.S. Nuclear Regulatory Commission;
(www.nrc.gov/waste/spent-fuel-storage/diagram-typical-trans-cask-system.doc).
Typicalspecifcations:grossweight(includingfuel)50,000pounds(25tons);caskdiam-
eter4feet;overalldiameter(includingimpactlimiters)6feet;overalllength(including
impactlimiters)20feet;capacityupto4PWRor9BWRfuelassemblies.
NationaI Science 7eachers Association 16
Several different cask designs have been
approved for use by the NRC, and SNF has
been moved across the country in casks since
1964. Before 2003, more than 1,000 NRC-
regulated shipments were made and only four
accidents were recorded (NRC 2003). None of
these accidents resulted in the release of ra-
dioactive material.
Te NRC has performed a number of com-
puter modeling tests and full tests on scale-mod-
el casks. However, no tests have yet been per-
formed on full-size casks. Te state of Nevada
has asked the NRC to conduct full-scale tests on
all proposed cask designs, both for transporting
and for storing SNF. Figure 9 illustrates typical
spent fuel transportation casks.
References
Andrews,A.December13,2006.CRS report for Con-
gress. Radioactive waste streams: Waste classifca-
tion for disposal.CongressionalResearchService.
www.fas.org/sgp/crs/misc/RL32163.pdf.
AssociatedPress.Las Vegas Review-Journal.2007.
LandSetAsideforYuccaRailStudy.January12.
www.reviewjournal.com/lvrj_home/2007/Jan-12-
Fri-2007/news/11933731.html.
Dilger,F.,andR.Halstead.October2005.Radwaste
management:RailroadingNevada.Nuclear En-
gineering International,pp.34–37.Alsoavailable
onlineatwww.state.nv.us/nucwaste/news2005/
pdf/nei05oct_caliente.pdf.
Fröman,N.December1,1996.Marie and Pierre Curie
and the discovery of polonium and radium.The
NobelPrizeFoundation.http://nobelprize.org/no-
bel_prizes/physics/articles/curie.
Halstead,R.2002.YuccaMountaintransportation
issues.PresentationmadeattheUNLVYucca
MountainEducationProjectTownHallMeet-
ing,November14,2002,“WhatIsBeingDoneto
ProtectNevada?:TransportationIssues.”www.
library.unlv.edu/yucca/index.html;MicrosoftWord
Documentavailableatwww.library.unlv.edu/yuc-
ca/statenov02.doc.
Kane,D.2002.YuccaMountainProject.Paperpre-
sentedtotheUniversityofNevada-LasVegas.
www.library.unlv.edu/yucca/YMPtalkKane.pdf.
Lamb,M.,andM.Resnikof.2001.Radiological
consequences of severe rail accidents involving
spent nuclear fuel shipments to Yucca Mountain:
Hypothetical Baltimore rail tunnel fre involving
SNF.NewYork:RadioactiveWasteManagement
Associates.www.state.nv.us/nucwaste/news2001/
nn11459.pdf.
Moss,W.,andR.Eckhardt.1995.Thehumanplu-
toniuminjectionexperiments:Radium—the
benchmarkforalphaemitters.Los Alamos Science,
No.23:224–233.http://library.lanl.gov/cgi-bin/get-
fle?23-10.pdf.
U.S.DepartmentofEnergy(DOE),OfceofCivil-
ianRadioactiveWasteManagement.February
2002.Final environmental impact statement for a
geologic repository for the disposal of spent nuclear
fuel and high-level radioactive waste at Yucca
Mountain, Nye County, Nevada.DOE/EIS-0250.
www.ocrwm.doe.gov/documents/feis_2/index.htm.
U.S.DepartmentofEnergy(DOE),OfceofCivilian
RadioactiveWasteManagement.January2006.
Transportation of spent nuclear fuel and high-level
radioactive waste to Yucca Mountain: Frequently
asked questions.www.ocrwm.doe.gov/transport/
pdf/snf_transfaqs.pdf.
U.S.DepartmentofEnergy(DOE),OfficeofEnvi-
ronmentalManagement.December2000.The
current and planned low-level waste disposal
capacity report revision 2.www.em.doe.gov/
pdfs/llwrev2.pdf.
U.S.NuclearRegulatoryCommission(NRC).March
2003.Safety of spent fuel transportation.NUREG/
BR-0292.www.nrc.gov/reading-rm/doc-collec-
tions/nuregs/brochures/br0292/br0292.pdf.
UnitedNationsOfcefortheCoordinationof
HumanitarianAfairs.2000.Chernobyl: A continu-
ing catastrophe.Geneva,Switzerland:TheUnited
Nations.www.chernobyl.info/resources/qms_ocha-
Bericht.pdf.
Radioactive Waste: Resources for Environmental Literacy
17
This section provides an overview of the three
student activities available for use, a list of pos-
sible student misconceptions, ideas for assessing
student learning, and some recommended re-
sources. Many of the websites cited in this docu-
ment contain useful graphics that can be used in
class discussions. Te student activities and the
assessment materials can be copied directly and
distributed to students as handouts.
Activities Overview
Physics teachers typically have easy access to both
demonstrations and student laboratory activities
dealing with radioactivity; the frst two activities
included here are ofered as possible alternatives.
Te fnal activity should be undertaken if time al-
lows. Teachers looking for additional student ac-
tivities can fnd them online at the NRC’s Teachers’
Lesson Plans (www.nrc.gov/reading-rm/basic-ref/
teachers.html) and at MERLOT (Multimedia Edu-
cational Resource for Learning and Online Teach-
ing; www.merlot.org).
Activity 1:
Detecting Radiation
Tis activity can be carried out either as a dem-
onstration or by teams of students, depending
on the number of Geiger counters available. In
one class period, this activity can introduce stu-
dents to background radiation and the inverse
square law. As a homework assignment, students
can determine their own approximate radiation
dose based on the EPA’s website. Te next day,
the class can compare the results and can specu-
late on the reasoning behind any extremely high
or low fndings.
Activity 2:
Half-Life
Using M&Ms or pennies, students collect data
that simulates the mathematics of radiation
half-life. Te activity and follow-up discussion
will require a full class period (in addition to a
homework reading assignment). As an exten-
sion, some students may want to fnd the expo-
nential regression equation of the data.
Activity 3:
Making Decisions
Tis culminating activity engages students in
decision making with regard to the controversy
over disposal of radioactive waste. Each of the
three “task forces” (Yucca Mountain Site, Nucle-
ar Waste Transportation, and Global Concerns)
will examine the pros and cons of diferent as-
pects of radioactive waste disposal and prepare
and present their fndings in a class forum. Much
of the work can be done outside of class, but two
or three days of in-class time will be needed for
the forum presentations.
Teaching Approach
NationaI Science 7eachers Association 18
It might be advantageous to organize the
task forces frst and then assign the research and
coordination of the group eforts as homework
over several weeks—during which the class can
move forward in studying other science topics.
Te forum can then be scheduled based on a
convenient class time.
Misconceptions
Students may have misconceptions about some
of the ideas presented in this module. For exam-
ple, students may take isotopes to be something
in addition to atoms or as only the unusual un-
stable atoms, they may believe that to fnd the
half-life of a decaying substance you need to
halve the mass and volume of that substance,
and they may confuse contamination and ir-
radiation. Te following are some of the other
misconceptions that students may have:
Atoms cannot be changed from one element
to another.
Neutrons and protons have no internal
structure.
Nothing is radioactive unless it is exposed
to radioactivity.
Radiation causes cancer; thus, it cannot be
used to cure cancer.
Once a material is radioactive, it is radioac-
tive forever.
Radioactivity frst appeared during World
War II.
Fission and fusion are the same; fssion is
more powerful than fusion.
Nuclear power plants produce harmful ra-
dioactive waste, while other forms of elec-
trical generation do not.
Nuclear power causes global warming.
•
•
•
•
•
•
•
•
•
Assessing Student Learning
Following Activity 3, students can be asked to
individually write an essay responding to the
possibility that U.S radioactive waste might
be stored in Russia (see the handout “What
Should Be Done With Radioactive Waste?”).
This should supplement, rather than replace,
the usual tests given on the subject of radia-
tion and radioactive waste.
Recommended Resources
IonisingRadiationandHealth:RiskAnalysis,WithPar-
ticularAttentiontoRadioactivity(www.abelard.
org/briefngs/ionising-radiation.asp)
Asimple-to-understandanduser-friendlyintro-
ductiontobasicradiationconceptsandhealth
riskassessments.
CivilianNuclearWasteDisposal(www.ncseonline.
org/NLE/CRSreports/Waste/waste-2.cfm?&CFID=31
5289&CFTOKEN=81581403)
ThisCongressionalResearchService(CRS)brief,
availablethroughtheNationalLibraryfortheEn-
vironment(NLE),includesageneraldiscussionof
theissuesinvolvedindealingwithnuclearwaste.
TransportationofSpentNuclearFuel(www.ncseon-
line.org/NLE/CRSreports/energy/eng-34.cfm?&CFID
=315289&CFTOKEN=81581403)
ThisCRSreport,availablethroughNLE,discusses
therisksoftransportingnuclearmaterials,aswell
asthevarioussafetyteststheU.S.government
requiresfortransportvehicles.
YuccaMountainRepository(www.ocrwm.doe.gov/
ym_repository/index.shtml)
ThisDOEsitedescribestheefortstodetermine
ifYuccaMountainisasafedisposalsiteforradio-
activewaste.
TheRadiationInformationNetwork(www.physics.isu.
edu/radinf)
ThisIdahoStateUniversitysitecontainsalong
listofreferencesthatincludeanintroductionto
radioactivity,radioactivityandnature,radiation
efects,andrisk.
MERLOT(MultimediaEducationalResourceforLearn-
ingandOnlineTeaching)(www.merlot.org).
Thissitehasagoodcollectionofanimationsand
otherresourcesdevelopedbyphysicsdepart-
mentsfromaroundtheworld,includingactivities
Radioactive Waste: Resources for Environmental Literacy
19
onisotopesandonradioactivedecay.Conduct
anadvancedsearchfor“nuclear”tofndrelated
lessonplansanddemonstrations.
AReporter’sGuidetoYuccaMountain(http://www.
nsc.org/public/issues/yuccapdf.pdf)
Thisonlinebackgroundguide,publishedbythe
NationalSafetyCouncilunderagrantfromthe
EPAinJanuary2001,includesanexplanationof
radiationandaglossarythatwouldbeusefulfor
physicsstudents.
UnderstandingRadiation(www.nsc.org/issues/
radisafe.htm)
TheNationalSafetyCouncil’sEnvironmental
HealthCentermaintainsthissiteonradiation
andradioactivewaste.Itincludessectionson
understandingradiationanditsuses,low-level
radioactivewaste,andYuccaMountain.
Teachers’LessonPlans(www.nrc.gov/reading-rm/ba-
sic-ref/teachers.html)
Thismaterial,preparedbytheNRC,containsan
introductiontoradioactivityalongwithseveral
usefulactivitiesfortheclassroom.
Radioactive Waste: Resources for Environmental Literacy
21
Student Activities
A second detector that may be available for
use in high school classes is a radiation detector
used by Civil Defense ofcials during the Cold
War. Tese yellow handheld units were widely
distributed and, although many have been dis-
carded, renewing batteries can frequently allow
them to function as Geiger counters. In addi-
tion, many hospitals have radiation units that
are run by health physicists who welcome visits
from local high school classes, as do many uni-
versity laboratories.
The activity can also be carried out as a
teacher demonstration if only one counter is
available. If more are available, it is better to
have students work in small groups. If it is to
be conducted as a student experiment, each
group will need the laboratory handout “De-
tecting Radiation.”
As an additional project, some students
may want to construct a cloud chamber—one of
the earliest particle detectors. Tey are easy to
construct but ofen tricky to make operational.
Step-by-step instructions can be found on Andy
Foland’s Cloud Chamber Page at www.lns.cor-
nell.edu/~adf4/cloud.html.
Activity 2:
Half-Life
Distribute the “Half-Life” instruction sheet
with data table to student groups. Be sure that
Activity 1:
Detecting Radiation
Since radioactivity cannot be detected by the
human senses even when it is present in large
quantities, students are not aware that they
are continuously surrounded by nuclear ra-
diation. This activity uses a radiation detector
to measure the radioactivity in everyday sur-
roundings and compare it with radioactivity
from other sources.
Before beginning the activity, students must
learn how a Geiger counter works (see Figure 10)
and, if they are going to handle it, how to handle
it properly. A Geiger counter is basically a tube
flled with gas, with a window made of a very
thin metal at one end. A wire runs through the
center of the tube and is held at a high positive
voltage. When a beta or a gamma particle enters
the tube, it knocks electrons of of the gas atoms.
Te electrons accelerate toward the central wire,
knocking more electrons of. Te electrons are
collected by the central wire and produce a pulse
of current that signals the presence of a radioac-
tive particle in the Geiger tube. Alpha particles
cannot enter the tube because they are stopped
by the very thin metal window of the tube.
1
Tis activity is adapted from the U.S. Nuclear Regulatory
Commission’s Teachers’ Lesson Plans, Instructional Unit
1—Radiation, available at www.nrc.gov/reading-rm/basic-ref/
teachers.html.
NationaI Science 7eachers Association 22
they collect data and prepare graphs and that
they follow up by searching for answers to the
questions that follow the simulation part of
the activity. As an extension, some students
may want to find the exponential regression
equation of the data.
Activity 3:
Making Decisions
The task force sections of the handout pro-
vide questions to guide the work, and the
“Recommended Resources” in the “Teach-
ing Approach” section can help to get them
started. Useful maps and other visual mate-
rials are embedded in many of the reference
materials and can be posted throughout the
classroom to help stimulate interest in the
Iigure 10. How a Ceiger Counter Works
Source: Wiley Publishing
work of the task forces. If an opportunity ex-
ists for working with other disciplines (e.g.,
history or social studies), you may want to
invite your colleagues to integrate the stu-
dents’ work on the policy issues involved in
the long-term storage of high-level nuclear
waste into their offerings.
For purpose of assessment, it is important
to assess both the clarity and organization of the
students’ presentations, in addition to the critical
analysis each task force uses to support its posi-
tion paper. Te forum presentations and posi-
tion papers also ofer an opportunity to evaluate
the depth of understanding, quality of synthesis,
and grasp of the underlying science attained by
each group. Te students themselves can also
carry out peer evaluations, if that strategy is use-
ful in the classroom.
5:31
photon or
charged
particle
Gas
molecule
electron
Positive
wire
Wire electrode
Gas molecule
High
voltage
Counting device
Window
High-energy particle
or photon
R
+ -
Radioactive Waste: Resources for Environmental Literacy
23
Student Materials
Detecting Radiation
Half-Life
Making Decisions
What Should Be Done With Radioactive Waste?
NationaI Science 7eachers Association 24
Detecting Radiation
Part I:
Radioactivity in the Environment
Afer setting up the radiation detector (or afer the teacher sets it up), count for several minutes
and determine the average number of counts per minute you detect. Tis counting rate is called the
background radiation.
What value did you get?
How does it compare with the count obtained by groups in other parts of the room?
Once you have determined the background radiation, you are ready to explore radioactive
materials in the classroom. Te teacher will provide you with several natural sources of
radioactivity (minerals such as pitchblende, orange Fiesta ware dishes, cloisonné jewelry, a
luminescent clock face, or commercial sources from science supply houses). Place each substance
approximately 3 cm from the thin window of the Geiger tube. Determine the number of counts
per minute from the material.
What is the range of radiation values for the material?
How do the values compare to background radiation?
Next, you will determine the penetrating properties of diferent types of radiation. Geiger coun-
ters detect gamma and beta particles but not alpha particles, because alpha particles cannot
penetrate the metal window material. One by one, place each of the materials 3 cm from the
counter and record their counting rate afer shielding the counter successively with (1) sheets of
thin paper, (2) sheets of aluminum foil, and (3) a fairly thick piece of iron, steel, or lead.
Assuming that gamma radiation is more energetic than beta particles, do the materials vary
from one another with regard to the proportion of gamma and beta radiation?
Which form of external radiation—beta or gamma—presents a greater hazard
To determine the radiation dose to which you are exposed and some of the factors that
influence that dose, complete the Calculate Your Radiation Dose exercise available at www.
epa.gov/radiation/students/calculate.html.
What average radiation dose are you subject to? How does it compare to other students in
the class?
Which variable is the greatest contributor to your background radiation? Did any variables
surprise you?
1.
•
•
2.
•
•
3.
•
•
4.
•
•
Radioactive Waste: Resources for Environmental Literacy
25
Part II:
The Inverse Square Law
A primary rule in handling radioactive sources is to hold them as far away from you as possible.
Moving away from radioactive sources reduces exposure rapidly because the number of radio-
active particles that cross a square centimeter of area each minute is inversely proportional to
the square of the distance from the source to the area. In this investigation, you will use the thin
window of the Geiger counter as a standard area.
Procedure
Select the strongest gamma source available. Place the source material so that it is 1 cm from the
window of the counter (with no shields in place). Determine the number of counts each minute
and record the result. Next, move the counter so that its window is 2 cm from the material. Again
determine the number of counts each minute and record the results. Repeat this procedure until the
counting rate reaches the background rate.
Questions
Plot your measured counting rates versus the square of the distance of the source material away from
the detector window.
What is the shape of your graph?
Does it agree with the predictions of the inverse square law?
Compare the counting rate at a distance
of 3 cm measured during the frst part of this investigation to the rate measured
this time.
Are these rates the same? Would you expect them to be? Explain your answer.
1.
2.
3.
NationaI Science 7eachers Association 26
Half-Life
In this investigation, each group will simulate the radioactive decay of a mythical element. Radioac-
tive substances exhibit the property that the number of nuclear particles that decay is proportional
to the number of radioactive nuclei that are present. Scientists call the original radioactive nuclei the
parent nuclei and the decayed nuclei the daughters. A certain percentage of the parent nuclei decays
in a given time interval that can last from a few seconds to thousands of years. Te result is that afer
certain equal lengths of time—called half-lives—the remaining number of parent radioactive nuclei
is half the number present at the beginning of the time period. Each group will model this decay
behavior by shaking a box of M&M candies (Eminemium) or pennies (Lincolnium) over and over
again, each time eliminating the number of “daughter nuclei” that have “decayed” (before proceed-
ing determine if the M-side or the Lincoln head up or down represents a decay).
Procedure
Each person in a group will have a container and an initial number of M&M candies or
pennies. Count the original number of parent radioactive nuclei and enter it in a data table
as the number left at the zero-shake.
Put the parent nuclei in the box. Shake the box a few times to disturb the initial orientation
of the individual candies or pennies; then carefully pour the particles from the box onto a
clean sheet of paper on a desk.
Separate the candies with the M-side up from those with the M-side down (or the heads
from tails with the pennies). Remove and dispose of the radioactive decay material
(based on the orientation that was decided before beginning the process).
Count the parent nuclei that remain and enter this number in a data table as the number lef
afer the frst shake. Repeat this process until no candies or pennies remain.
Part A:
Graph the number of parent nuclei versus the number of shakes.
What does the graph look like?
Is the relationship between nuclei remaining and the number of shakes positive or negative?
Explain. If the number of shakes is taken to be a stand-in for time, give an example of a quantity
that has the opposite relationship.
What is the probability that each particle will remain in the system? What is the basis for this
generalization?
1.
2.
3.
4.
1.
2.
3.
Radioactive Waste: Resources for Environmental Literacy
27
SampIe Data 7abIe
Shake
Number
0 1 2 3 4 5 6 7
StudentA
Numberleft
aftershake
StudentB
Numberleft
aftershake
StudentC
Numberleft
aftershake
StudentD
Numberleft
aftershake
Totalnuclei
leftafter
shake
Part B:
Look up the half-life period for some isotopes of carbon, iodine, phosphorus, barium, potassium, argon
and uranium. (See Resources on Isotopes at wwwrcamnl.wr.usgs.gov/isoig/period/index.html.)
Are all of the isotopes of the elements listed above radioactive?
What is the range of half-life periods?
Do isotopes of transuranic elements—such as plutonium—have half-lives?
Part C:
Do research to find resources discussing the uses of radioactive materials. While citing
your sources, describe in a few paragraphs why knowing half-life periods is essential for
using radioactive materials in (a) medicine, (b) the disposal of radioactive wastes, and (c)
archaeological dating.
1.
2.
3.
NationaI Science 7eachers Association 28
Making Decisions
Your class is engaged in Making SENSE: Safe Environmental Nuclear-Waste Sites for Eons, a proj-
ect to suggest long-term solutions of how the United States should deal with accumulating nuclear
wastes. Te paramount vision of the task forces is guided by this compelling question: What nuclear
waste legacy will future generations face?
The class will be divided into three task forces: the Yucca Mountain Site Task Force, the
Nuclear Waste Transportation Task Force, and the Global Concerns Task Force. Each group
will assume the roles of various segments of society: scientists, politicians, economists, environ-
mentalists, and public interest groups exploring policy decisions, considering possible trade-
offs, and examining risks accompanying long-term disposal of high-level nuclear waste.
Each task force will prepare a position paper describing its main arguments and conclu-
sions and will present the findings in a class forum.
Radioactive Waste: Resources for Environmental Literacy
29
The Yucca Mountain Site Task Force
Citing compelling national interests, the U.S. Department of Energy (DOE) notified the state of
Nevada that construction of the controversial Yucca Mountain nuclear waste dump would go
ahead (see “DOE Approves Nevada Nuclear Waste Site” at http://usgovinfo.about.com/library/
weekly/aa011202a.htm). On July 23, 2002, President Bush signed House Joint Resolution 87,
opening the avenue for DOE to prepare an application to obtain the Nuclear Regulatory Com-
mission license to proceed with the construction of the repository at Yucca Mountain.
Te Environmental Working Group estimates that approximately 45,662 metric tons of nuclear
waste are now stored at 72 commercial and 5 DOE sites across the country (Mayell 2002). If the
Yucca Mountain project is completed, once it has reached its capacity—projected to be 38 years
from now—there will still be 42,416 metric tons of spent nuclear fuel at other U.S. sites. Twenty-fve
nuclear power plants will have more nuclear waste at their sites than they do now, and many others
will have only slightly reduced amounts.
There are many facets to the story of Yucca Mountain, and the dilemma of nuclear waste
policy continues today. What happens if there is a mismatch between what science and geosci-
entists can provide and what society wants and needs?
Te Yucca Mountain Site Task Force should consider the following questions:
Considering the half-lives of the radioactive materials potentially to be stored at the Yucca
Mountain site, what are the pros and cons for doing so?
Which organizations and interest groups are in favor, and which are opposed? Are the argu-
ments for each scientific or political and economic? Has the news media taken a position?
How do the risks at Yucca Mountain compare to storing radioactive waste at above-
ground depositories at or near where they are created? How do they compare in terms
of cost and risk with proposals to dispose of them by deep-sea burial or by sending
them into space in rocket ships?
Is the process for making a national decision sufciently democratic?
What is the conclusion of this task force? Is it unanimous? If not, what are the counterargu-
ments of the minority?
What sources of information and arguments turned out to be most useful in reaching a
decision? Was the bias of the various sources obvious?
•
•
•
•
•
•
NationaI Science 7eachers Association 30
The Nuclear Waste Transportation Task Force
Moving spent nuclear fuel from nuclear reactors to the Yucca Mountain repository will involve
trucks, trains, or a combination of the two. Both means of transport create problems with the type
of transport and the means of containment.
One example is that a critical accident could cripple possible rail transportation of
spent nuclear fuel. Based on a hypothetical analysis of a Baltimore, Maryland, train ac-
cident in 2001 (see www.state.nv.us/nucwaste/news2001/nn11459.pdf), it is estimated that
32 square miles of land would be contaminated and there would be 4,000 to 28,000 latent
cancer fatalities over the course of 50 years.
Te Nuclear Waste Transportation Task Force should consider the following questions:
What are the chief hazards in transporting radioactive materials by trains, trucks, and ships?
How do they compare?
What are the technical problems of packing and transporting nuclear wastes?
How are current disposal sites distributed across the United States? How do the pro-
posed transportation routes for Yucca Mountain and other surface depositories differ?
Who is most at risk? Is the NIMBY (Not In My Backyard) syndrome response a signifcant fac-
tor?
What are the comparative risks to individuals and areas for the transportation of radio-
active wastes to the Yucca Mountain site, surface depositories, and ports for shipping
for deep-sea burial? What about costs?
How do various organizations and interest groups stand with regard to transportation issues?
Are their arguments mainly scientifc or economic and political?
What is the conclusion of this task force? Is it unanimous? If not, what are the counterargu-
ments of the minority?
What sources of information and arguments turned out to be most useful in reaching a
decision? Was the bias of the various sources obvious?
•
•
•
•
•
•
•
•
Radioactive Waste: Resources for Environmental Literacy
31
The Global Concerns Task Force
With the March 2001 opening of the 1,000-megawatt (MW) Rostov-1 reactor, Russia now operates
30 nuclear reactors at 10 locations—all west of the Ural Mountains (National Research Council of
the National Academies 2003). Although Russia’s nuclear plants account for at least 14% of its total
electricity generation, their plants are aging and the industry has been hit hard by Russia’s transition
to a market economy. Russia shut down four reactors that were over 30 years old (the maximum pre-
scribed service life for a reactor), seven more have just reached the 30-year mark and an additional
eight are over 20 years old.
Te Global Concerns Task Force should consider issues and policies guided by global con-
cerns—particularly the disposal of nuclear waste generated by nuclear-powered submarines and
other vessels, the use of nuclear armaments, and the emergence of additional nuclear waste due to
the proliferation of nuclear power plants across the globe.
Researching articles found in scientifc journals, newspapers, and magazines is a good start because
these original documents ofen point to possible connections among scientifc, political, economic, and
environmental concerns arising from the global need to deal with long-term storage of high-level nuclear
wastes. Although the Cold War is over, the proliferation and disposal of nuclear weapons still yield prob-
lems and perils to the international community, including concern with possible international terror-
ism.
Te Global Concerns Task Force should consider the following questions:
How do Russia and other countries that use nuclear power dispose of the generated wastes?
Which countries are involved?
To what extent do diferent countries depend on nuclear power? Is that use increasing or de-
creasing?
What is the nature and magnitude of international concern? Have serious problems occurred in
any country as a consequence of their handling of the nuclear wastes?
What is the particular hazard created by the sinking of nuclear-powered submarines?
Do stored radioactive wastes pose potential problems with international terrorism?
What is the conclusion of this task force? Is it unanimous? If not, what are the counterargu-
ments of the minority?
What sources of information and arguments turned out to be most useful in reaching a deci-
sion? Was the bias of the various sources obvious?
References
Mayell,H.2002.Webmapshowsnuclearwasteshippingroutes.National Geographic News.http://news.nation-
algeographic.com/news/2002/06/0611_020611_waste.html
NationalResearchCounciloftheNationalAcademies.CommitteeonEndPointsforSpentNuclearFuel
andHigh-LevelRadioactiveWasteinRussiaandtheUnitedStates,OfficeforCentralEuropeand
EurasiaDevelopment,Security,andCooperation.2003.End points for spent nuclear fuel and high-level
radioactive waste in Russia and the United States.Washington,DC:NationalAcademiesPress.
•
•
•
•
•
•
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NationaI Science 7eachers Association 32
The Bush administration said Saturday that
it would open formal negotiations with Rus-
sia on a long-discussed civilian nuclear agree-
ment that would pave the way for Russia to
become one of the world’s largest repositories
of spent nuclear fuel.
President Vladimir V. Putin has been look-
ing to expand the country’s role in the multibil-
lion nuclear power business. Te United States
has traditionally opposed any such arrange-
ment, in part because of concerns about the
safety of Russian nuclear facilities, and because
the country has helped Iran build its frst major
nuclear reactor.
But administration ofcials said that once
Bush endorsed Putin’s proposal last year for Iran
to conduct uranium enrichment inside Rus-
sia—rather than in Iran, where the administra-
tion fears it would be diverted to weapons—it
made little sense to bar ordinary civilian nuclear
exchanges with Russia.
In announcing the change of course, the
White House made it clear that in return, it ex-
pected Putin’s cooperation in what promises to
be a tense confrontation with Iran on forcing it
to give up the enrichment of uranium.
U.S. to negotiate Russian storage of atomic waste
David E. Sanger and Jim Rutenberg, The New York Times,
July 9, 2006
Bush has charged that the enrichment
is intended to feed a secret nuclear weapons
program. “We have made clear to Russia that
for an agreement on peaceful nuke coopera-
tion to go forward, we will need active coop-
eration in blocking Iran’s attempts to obtain
nuclear weapons,” said Peter Watkins, a White
House spokesman.
So far, Russia has backed the United States
in its fundamental demands but balked at the
imposition of sanctions or the passage of any
United Nations Security Council resolution that
Bush could later use as a justifcation for mili-
tary action.
Te Washington Post frst reported the shif
on Saturday.
A spokesman for Putin declined to com-
ment. But Sergei G. Novikov, a spokesman for
Russia’s Atomic Energy Agency, said in a tele-
phone interview that Russia and the United
States had been talking about the subject in re-
cent months.
He added that he did not expect that an
agreement would be signed during the Group
of 8 summit meeting in St. Petersburg next
weekend, but rather that Bush and Putin might
What Should Be Done With Radioactive Waste?
For this exercise, you will need to read the New York Times (www.nytimes.com) article “U.S. to Nego-
tiate Russian Storage of Atomic Waste” by David Sanger and Jim Rutenberg, published July 9, 2006.
Compare the approach to the disposal of radioactive waste discussed in this article with other
proposed options, such as local storage or storage in the Yucca Mountain site. In your essay, take
physics, advantages, hazards, and risks into account.
Radioactive Waste: Resources for Environmental Literacy
33
issue a vaguely worded statement on increased
nuclear cooperation, and then instruct their
governments to work on an agreement that
might lift the current restrictions. The United
States has similar deals with a variety of na-
tions, including China.
If such a statement is issued, Novikov
said, negotiations on the details would prob-
ably take at least several months. “I would
rather not talk about any expectations, so as
not to experience any frustration should they
not come true,” he said.
For Bush, an accord could help solve two
problems: where to send a growing stockpile of
waste from nuclear fuel that originated in the
United States, and how to keep Russia on board
in pressuring Iran to give up its uranium enrich-
ment programs.
Under American law, the United States
retains control over nuclear fuel, and nuclear
waste, made from uranium that originated in
the United States. As a result it has barred South
Korea, Taiwan and other states that bought
American fuel from transferring it to Russia,
which changed its laws several years ago to enter
the multibillion dollar business of storing nucle-
ar waste. Te proposed agreement does not ap-
pear to be intended to allow storage in Russia of
waste from reactors in the United States.
But a negotiation would also help provide
Putin with an economic incentive for giving up
nuclear aid to Iran, which has long been one of
the Bush administration’s objectives. On Fri-
day, in Chicago, Bush alluded to the difculty
in getting Russia and China to join in sanctions
against Iran or North Korea.
“You know, some nations are more com-
fortable with sanctions than other nations,
and part of the issue we face in some of these
countries is that they’ve got economic inter-
ests,” Bush told reporters.
In two previous trips to St. Petersburg as
president, Bush tried to persuade Putin to give
up a lucrative contract to supply the reactors to
Iran’s Bushehr nuclear plant. But Russia resisted,
and eventually Bush accepted a deal in which
any nuclear fuel Russia sells to Iran would have
to be returned to Russia afer use, so that pluto-
nium could not be removed from the waste for
military use.
Congress would have the right to review
any agreement. But since the administration
just concluded an accord with India, which
requires a more intensive nuclear review, ad-
ministration officials said they thought Russia
would win approval.
Senator Charles E. Schumer, Democrat of
New York and a regular administration critic,
ofered tentative approval of the idea. “While
the devil is certainly in the details, given that our
greatest danger right now is a nuclear Iran and
North Korea, we very much need Russia’s help,”
he said in an e-mail message.
Congressman Edward R. Royce, Republi-
can of California and the chairman of the House
Subcommittee on International Terrorism and
Nonproliferation, said that he was supportive of
the idea but that he expected to hold hearings.
Rep. Edward J. Markey, a Massachusetts
Democrat who is the co-chairman of the Bipar-
tisan Task Force on Nonproliferation, harshly
criticized Bush over the move.
NationaI Science 7eachers Association 34
“President Bush’s foreign policy has become
so hollow that his favorite bargaining position
is to give everything away. He is repeatedly re-
warding bad behavior,” he said in a statement.
Outside experts with whom the adminis-
tration had been consulting on the deal said
they had sensed a recent cooling off on the
idea as Russia continued to hold out on bring-
ing sanctions against Iran. The idea seemed to
pick up again several weeks ago when Russia’s
top atomic energy official, Sergei V. Kiriyen-
ko, lobbied hard for it during meetings with
counterparts in Washington.
At the same time, the administration
seemed to come around to thinking that the
negotiations for the deal—which could take
place over months or even years—could help
bring Russia more fully on board with the
administration’s efforts to rein in Iran, said
Robert J. Einhorn, senior adviser at the Center
for Strategic and International Studies and a
former assistant secretary of state for nonpro-
liferation in the Clinton administration and
briefly in Bush’s.
“Tey had reached the conclusion that en-
tering the negotiations would provide continu-
ing leverage,” Einhorn said.
Te idea is not new, and some outside ex-
perts have been calling for just such an arrange-
ment for months. Te Council of Foreign Rela-
tions did so in a report on United States-Russian
relations in March that was highly critical of
Putin’s policies.
“Te idea was to create a greater founda-
tion for nuclear cooperation with the Russians
to support staying on the same track with Iran,”
said Stephen Sestanovich, a senior fellow at the
council and an adviser on Russia for former
President Bill Clinton.
But the report also cited such an agreement
as a way to foster cooperation on securing spent
fuel and providing nuclear energy to nonnuclear
nations seeking to develop their own enrich-
ment facilities.
C. J. Chivers contributed reporting from Moscow for
this article, and Matthew L. Wald from
Washington. Copyright 2006, by the New York Times
Company. Reprinted with permission.