Worst Case Credible Nuclear Transportation Accidents: Analysis for

112 Pages·2002·3.6 MB·English

by  Marvin Resnikoff

Worst Case Credible Nuclear Transportation
Accidents:
Analysis for Urban and Rural Nevada

Matthew Lamb and Marvin Resnikoff, Ph.D.
Radioactive Waste Management Associates
And
Richard Moore, P.E.
August 2001

Radioactive Waste Management Associates
th
526 W. 26 Street #517
New York, NY 10001
Table of Contents
Executive Summary.........................................................................................................................................i
Introduction.....................................................................................................................................................1
1. Accident Locations and Potential Radionuclide Releases...................................................................4
Accident Locations.................................................................................................................................4
Release Estimates....................................................................................................................................5
Postulated Release Fractions and Inventory............................................................................................9
Severity of the Accidents Being Considered in this Analysis...............................................................11
2. Downwind Radioactive Particulate Concentrations..........................................................................13
3. Las Vegas Specific Accident.............................................................................................................15
Individual Dose and Surface Contamination Estimates........................................................................15
Population Dose Estimates for Las Vegas Accidents............................................................................20
Contamination Inside Hotels: A Hypothetical Example.......................................................................25
Las Vegas Emergency Response and Evacuation.................................................................................27
Las Vegas Decontamination.................................................................................................................40
Other Factors Affecting Cleanup Cost Estimates..................................................................................47
4. Rural Truck Accident: West Wendover, Nevada................................................................................49
General Characteristics of West Wendover, Nevada............................................................................49
Individual Dose and Surface Contamination Estimates........................................................................49
Population Density Estimate.................................................................................................................52
Contamination Inside Hotels: A Hypothetical Example.......................................................................56
5. Rural Rail Accident: Carlin, Nevada....................................................................................................58
General Characteristics of the Carlin Tunnel Region............................................................................58
Individual Dose and Surface Contamination Estimates........................................................................59
Population Density Estimate.................................................................................................................61
Population Dose Estimate.....................................................................................................................61
Possible Contamination of the Humboldt River....................................................................................63
Conclusions...............................................................................................................................................67
References.................................................................................................................................................71

Appendices
A. Discussion of Severe Accident Release Estimates A-1
B. Category 6 Accident Contamination Charts B-1
C. Alternative Population Density Calculation C-1
D. Detailed Population Dose Calculations D-1
E. Estimation of Indoor Air Concentration E-1
Nevada Spent Fuel Transportation Severe Accident Analysis Page i
Executive Summary

If the proposed Yucca Mountain waste repository opens, a large number of irradiated fuel
and high-level waste shipments will converge in Nevada. According to the Department of
Energy (DOE), there could be between 23,000 and 96,000 shipments to Yucca Mountain over
four decades1. Depending on a range of factors, such as the eventual transportation mode and
any safety precautions that may be required, hundreds of accidents are expected nationwide.
Some of these accidents could result in release of radioactive materials.

As prior reports prepared by RWMA for the State of Nevada show2, DOE has
systematically underestimated the potential human health impacts from severe accidents and
completely ignored their potential economic impacts. The cost of cleanup, evacuation and
business loss resulting from a severe accident in a generic urban area can range from several
billion to several hundred billion dollars. An accident in a rural area will have a different set of
consequences, but has the potential to be as devastating as an accident in a more populated area.

Except for population density, the previous analyses were not location-specific. In
contrast, this study estimates site-specific accident consequences for select urban and rural
locations in the State of Nevada. These were chosen based on the locations of proposed and
likely truck and rail transportation corridors en route to the geologic repository at Yucca
Mountain. For the urban scenarios, representative truck and rail locations were chosen in Las
Vegas, a potential crossroads for fuel traveling to the proposed facility. The rural truck accident
location was chosen to be near the Utah-Nevada border along I-80, in the town of West
Wendover. The chosen rural rail location is at the Carlin Tunnel along the Union Pacific and
Southern Pacific railroads in western Elko County.

This study estimated the nature and amount of radioactivity that could be released from a
spent fuel shipping cask in the event of a serious accident, based on industry literature. From
these release estimates, we estimated the extent of contamination and the consequences to
individuals and collective populations associated with this contamination. Based on extensive
discussions with local emergency personnel, this report also discusses the likely response by
emergency personnel to an accident of this nature. Finally, the report lays out the
decontamination technologies available and comments on their cost and effectiveness.

Each cask that would be shipped to Yucca Mountain contains an enormous inventory of
radioactive material. Casks are not designed to withstand all credible highway and rail accidents.
Even a small release in terms of the fraction of the entire inventory that is released, such as those
considered in this report, can lead to major health and economic consequences.

Our calculations assumed average, site-specific meteorological conditions and wind
speeds. We used standard computer software, such as HOTSPOT and RISKIND, to model
downwind air and surface particulate concentrations. We further assumed a severe impact would

1 U.S. Department of Energy, 1999. Draft Environmental Impact Statement for a Geologic Repository of Spent Nuclear Fuel and
High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada. (DOE/EIS-0250D). pp. J-10.
2 Lamb, M and M Resnikoff, “Consequence Assessment of Severe Nuclear Transportation Accident in an Urban Environment,”
Radioactive Waste Management Associates, 5 July 2000
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Nevada Spent Fuel Transportation Severe Accident Analysis Page ii
lead to a ground level puff release of radioactive particulates. Our release estimates did not
consider the accident scenario involving “fire-only” conditions, which would result in a more
protracted release of material and a higher effective release height.

Near a transportation accident, this report estimates acute radiation doses due to
inhalation of a passing radioactive cloud to be in the hundreds of rems close to the release
location. This is a thousand times what a person receives from background radiation in a year.
Thousands of people are likely to be in the downwind path. For example, this study estimated
that over 138,000 persons would be affected by a severe rail accident releasing radioactive
material in Las Vegas. Persons indoors would also be exposed. If ventilation systems were not
shut off, radioactive particulates would settle within hotels and other buildings, contaminating
rugs, furniture, beds, and causing a radiation dose to those inside.

Discussions with emergency personnel in Las Vegas and Clark County clearly indicate
the accident would overwhelm local response capabilities. Before local emergency responders
could accurately assess the problem, the radioactive plume would have already contaminated an
extensive area. Radioactive particulates settling on roads and highways are likely to be spread
by traffic, possibly contaminating distant locations and extending the area of contamination past
that assumed in this study. This may result in the contamination of many more people than was
estimated in this report.

Given the high number of people exposed, local responders will not be able to identify,
let alone effectively quarantine, contaminated people. Thus, it will be extremely difficult to stop
the spread of contamination. Initial decontamination efforts will probably be limited to
emergency responders and people in the closest vicinity of the accidents. Decontamination of
the affected population in general will be a massive effort.

Evacuation will be difficult at best. Spontaneous evacuation by people not in the
contaminated area will probably occur in great numbers, making the targeted evacuations much
more difficult to complete. At a minimum, the evacuation of highly contaminated areas would
be necessary. For a rail accident, evacuation would have to be in a radius greater than one
kilometer; this would represent a large number of people if the accident took place near the Las
Vegas Strip.

In the case of an accident in Las Vegas, consideration would have to be given to closing
McCarren airport in order to prevent the migration of contaminated persons. Alternately, all
passengers would have to be screened for contamination. This would require a huge amount of
resources that could be better utilized dealing with the major issues.

The incident would overwhelm the capability of the local medical community. Blood
and urine samples of contaminated people should be taken to track the levels of contamination
and exposure, but this would be very difficult given the number of contaminated and potentially
contaminated individuals. Mental health resources would be overwhelmed as well.

Unless radionuclides, particularly cesium, were removed from surfaces, remaining
residents would be exposed for long time periods. Complete decontamination would be
Radioactive Waste Management Associates
Nevada Spent Fuel Transportation Severe Accident Analysis Page iii
prohibitively expensive and would also expose workers; a balance would take place between
clean-up costs and long-term radiation exposures. In this report we chose the EPA’s Protective
Action Guide as a criteria for decontamination; assuming that a person should not receive more
than 5 rems over a 50-year period, including initial inhalation due to the passing cloud. If areas
are not decontaminated, we estimate between 6,000 and 41,000 latent cancer fatalities would
result from exposure to radiation resulting from the rail accident in Las Vegas, depending on the
risk model. If radioactive contaminants were not remediated, there would be continuous direct
gamma exposure to remaining residents. Further, this would result in a tremendous concomitant
economic cost to the tourist industry. Social stigma costs are beyond the scope of this report.

Using the economic model of RADTRAN 5, evacuation and decontamination costs could
range to hundreds of billions of dollars. These potential costs greatly exceed the amount of
insurance coverage held by nuclear utilities or the Department of Energy. This raises the
question of how such an expensive endeavor would be financed. Government financing of
clean-up would require an act of Congress, which would significantly delay remedial action.

While the population densities are obviously lower in a rural area, an accident in West
Wendover on I-80, or a rail accident near the Carlin tunnel, both in Northern Nevada, would also
have serious consequences. I-80 is the main route into and out of West Wendover, as well as a
major cross-country thoroughfare. An accident that spread radioactive contamination could cut
off the exit and either leave cars trapped or have vehicles spread the contamination miles down
the highway. This report calculates the accident consequences in West Wendover. A rail
accident near the Carlin tunnel, in a canyon adjacent to the Humboldt River, would lead to
contamination of the river bed and water for miles downstream and leading to accumulations in
slowly moving sections of the river. Use of the river for recreation or drinking would be
curtailed for years to come.

This study shows the potentially disastrous consequences of an accident leading to the
release of radioactive material from a spent fuel transportation cask. It also underscores the
importance of preparation of emergency response for such an accident. Acknowledgement of the
potential for disaster, even if the probabilities are not high, is important in attempting to prepare
for an unprecedented spent fuel transportation campaign.

The tables below summarize the findings of this study. Table ES-1 presents a
comparison of the Las Vegas accidents discussed in this study with the urban ‘maximum
reasonably foreseeable’ accident scenarios listed in the DEIS for the Yucca Mountain Facility.
Table ES-2 presents a comparison of the rural accidents discussed in this study with the rural
‘maximum reasonably foreseeable ‘ accident scenario listed in the DEIS for the Yucca Mountain
Facility. The consequences estimated in this report are significantly higher than those estimated
in the Yucca Mountain DEIS, primarily due to the assumption of a higher population density and
an increased release fraction for cesium.
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Nevada Spent Fuel Transportation Severe Accident Analysis Page iv
Table ES-1: Comparison of State of Nevada and Yucca Mountain EIS Consequence
Assessments : Urban Accidents

Urban Truck Accident Urban Rail Accident
State of State of State of State of
YM DEIS, YM DEIS, YM DEIS, YM DEIS,
Nevada, Nevada, Nevada, Nevada,
Cat. 5a Cat. 6a Cat. 5a Cat. 6a
Cat.5a Cat.6a Cat.5a Cat.6a
Acute (24-hour)
not not not not not not
Population Dose 846 26,171
calculated calculated calculated calculated calculated calculated
(person-rem)b
Expected Latent not not not not not not
0.42-2.7 13-444
Cancer Fatalitiesc calculated calculated calculated calculated calculated calculated
1-year Population
not not not not
Dose (person- 29,514 9,400 915,968 61,000
calculated calculated calculated calculated
rem)b
Expected Latent not not not not
15-94 5 458-2,931 31
Cancer Fatalitiesc calculated calculated calculated calculated
50-year
not not not not not not
Population Dose 407,024 12,771,207
calculated calculated calculated calculated calculated calculated
(person-rem)b
Expected Latent 204- not not not 6,386- not not not
Cancer Fatalitiesc 1,306 calculated calculated calculated 40,868 calculated calculated calculated
Dose to
Maximally not not
3.9 38.5 4 22.5 224 26
Exposed calculated calculated
Individual (rem)d
Area
contaminated to
not not not not
greater than 5 11.1 192.2 104.7 1208.4
calculated calculated calculated calculated
rem long-term
dose (km2)
a. Release fractions are presented in Tables 1 and 2 of this report
b. The Yucca Mountain DEIS assumed an urban population based on the average densities in successive 8-kilometer rings around the 21
largest cities in the continental U.S. The State of Nevada estimated the population of the Las Vegas MSA using data from the 2000 U.S.
Census, and with the methodology explained in Section 3 of this report.
c. The Expected Latent Cancer Fatalities, and the probability of increasing a latent cancer fatality, are calculated in the Yucca Mountain DEIS
assuming a value of 0.0005 LCFs per person-rem exposure. The State of Nevada presents a range of latent cancer fatalities based on the
value of 0.0005-0.0032 LCFs per person-rem exposure. See Section 3, under "Population Dose Estimates for Las Vegas Accidents."
d. The Maximally Exposed Individual was assumed to be located 360 meters downwind of the release in the Yucca Mountain DEIS (pp. 6-31).
For comparison, the State of Nevada made the same assumption.
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Table ES-2: Comparison of State of Nevada and Yucca Mountain EIS Consequence
Assessments : Rural Accidents

Rural Truck Accident Rural Rail Accident
State of State of State of State of
YM DEIS, YM DEIS, YM DEIS, YM DEIS,
Nevada, Nevada, Nevada, Nevada,
Cat. 5a Cat. 6a Cat. 5a Cat. 6a
Cat.5a Cat.6a Cat.5a Cat.6a
Acute (24-hour) not not
not not not not
Population Dose 799 calculated calculated 393
calculated calculated calculated calculated
(person-rem)b
Expected Latent not not not not not not
0.4-2.6 0.2-1.3
Cancer Fatalitiesc calculated calculated calculated calculated calculated calculated
1-year Population
not not not not not
Dose (person- 27,886 430 13,760
calculated calculated calculated calculated calculated
rem)b
Expected Latent not not not not not
14-89 0.2 7-44
Cancer Fatalitiesc calculated calculated calculated calculated calculated
50-year
not not not not not not
Population Dose 388,326 191,859
calculated calculated calculated calculated calculated calculated
(person-rem)b
Expected Latent 194- not not not not not not
96-614
Cancer Fatalitiesc 1,243 calculated calculated calculated calculated calculated calculated
Dose to
Maximally not not not
1.73 17.1 3.9 26.9 267
Exposed calculated calculated calculated
Individual (rem)d
Area
contaminated to
not not not not
greater than 5 3.4 33.1 118.6 1202
calculated calculated calculated calculated
rem long-term
dose (km2)
a. Release fractions are presented in Tables 1 and 2 of this report
b. The Yucca Mountain DEIS assumed a rural population based on national averages for a representative rail route. The State of Nevada
estimated the rural truck population based on West Wendover, Nevada, and the rural rail population based on Elko, Nevada. See Sections 4
and 5 of this report.
c. The Expected Latent Cancer Fatalities, and the probability of increasing a latent cancer fatality, are calculated in the Yucca Mountain DEIS
assuming a value of 0.0005 LCFs per person-rem exposure. The State of Nevada presents a range of latent cancer fatalities based on the
value of 0.0005-0.0032 LCFs per person-rem exposure.
d. The Maximally Exposed Individual was assumed to be located 360 meters downwind of the release in the Yucca Mountain DEIS (pp. 6-31).
For comparison, the State of Nevada made the same assumption.
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Nevada Spent Fuel Transportation Severe Accident Analysis Page 1

Introduction

If the proposed Yucca Mountain waste repository opens, a large number of irradiated fuel
and high-level waste shipments will converge in Nevada. According to the Department of
Energy (DOE), there could be between 23,000 and 96,000 shipments to Yucca Mountain over
four decades3. Depending on a range of factors, such as the eventual transportation mode and
any safety precautions that may be required, hundreds of accidents are expected nationwide.
Some of these accidents could result in release of radioactive materials. DOE has estimated that
a maximum reasonably foreseeable truck or rail accident could release enough radioactive
materials to cause 4 to 31 latent cancer fatalities. DOE estimates the probability of such accidents
at 1.4 to 1.9 in 10 million per year.4

RWMA has previously evaluated DOE's accident consequence estimates. As prior reports
prepared for the State of Nevada show5, DOE has systematically underestimated the likely
human health impacts of severe accident. Moreover, DOE has completely ignored the potential
economic impacts of severe accidents. The cost of cleanup, evacuation and business loss
resulting from a severe accident in a generic urban area can range from several billion to several
hundred billion dollars. An accident in a rural area will have a different set of consequences, but
has the potential to be as devastating as an accident in a more populated area.

Except for population density, the previous analyses were not location-specific.
Assuming average weather conditions, average population density and a selected accident
severity, the health effects and economic consequences were calculated using standard computer
models, such RADTRAN46 and RISKIND7 and their associated economic models. The
accidents assumed in the previous analyses were the “maximum reasonably foreseeable accident
scenario” for rail and truck shipments as defined by the Department of Energy (DOE) in the draft
Environmental Impact Statement (EIS)8 for the proposed geologic repository at Yucca Mountain,
Nevada. Our previous studies did not investigate specific accident locations or specific details
about evacuation and decontamination following an accident.
This study estimates site-specific accident consequences for select urban and rural
locations in the State of Nevada. These were chosen based on the locations of proposed and
likely truck and rail transportation corridors en route to the geologic repository at Yucca
Mountain. For the urban scenarios, representative truck and rail locations were chosen in Las
Vegas, a potential crossroads for fuel traveling to the proposed facility. The rural truck accident
location was chosen to be near the Utah-Nevada border along I-80, in the town of West

3 U.S. Department of Energy, 1999. Draft Environmental Impact Statement for a Geologic Repository of Spent Nuclear Fuel and
High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada. (DOE/EIS-0250D). pp. J-10.
4 Ibid., pp. 6-31 to 6-33.
5 Lamb, M and M Resnikoff, “Consequence Assessment of Severe Nuclear Transportation Accident in an Urban Environment,”
Radioactive Waste Management Associates, 5 July 2000
6 Neuhauser and Kanipe, 1992. User’s Guide for RADTRAN 4. SAND89-2370, Sandia National Laboratories.
7 Yuan et al, 1995. RISKIND: A Computer Program for Calculating Radiological Consequences and Health Risks from
Transportation of Spent Nuclear Fuel. ANL/EAD-1. Argonne National Laboratory.
8 U.S. Department of Energy, 1999. Draft Environmental Impact Statement for a Geologic Repository of Spent Nuclear Fuel and
High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada. (DOE/EIS-0250D).
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Nevada Spent Fuel Transportation Severe Accident Analysis Page 2
Wendover. The chosen rural rail location is at the Carlin Tunnel along the Union Pacific and
Southern Pacific railroads in western Elko County.
The Las Vegas urban area is an interesting choice for a location-specific accident
scenario because it has very unusual, if not unique, economic and demographic characteristics.
Potential highway and rail routes to Yucca Mountain traverse the downtown Las Vegas area
known worldwide for its large casinos and resort hotels. High population densities are seen at
each of the major hotels. A large hotel could contain as many as 10,000 guests and 2,000
employees9. Many hotels and casinos are less than one-half mile from a potential shipping route,
and some hotel properties are physically adjacent to proposed routes to Yucca Mountain.
Las Vegas is one of the premiere tourist destinations in the country, attracting nearly 36
million visitors in the year 2000, filling approximately 125,000 hotel rooms10. In the event of a
radioactive release, evacuation would be difficult, owing to the highly transient population, the
fact that many visitors would not have access to a vehicle, and the concentration of people in a
relatively small area. The total time an area remains evacuated may be lengthy while cleanup
proceeds. As the center of Nevada’s most important industry, any accident resulting in the
closure of large casinos, even if temporarily, will have cascading effects on the economic well-
being of residents, local governments and the State.
Other aspects of Las Vegas’ unique nature make calculation of health effects very
difficult. It cannot be ascertained at this point whether, for example, a large hotel downwind
from a radioactive release would be able to shut off its ventilation system in time to prevent
contaminated air from entering the building. If the ventilation system were shut off too late, it
would have the effect of trapping radioactive material inside the hotel. On the other hand, given
sufficient time to shut off the air intakes to a hotel, the immediate consequences of a release
could be reduced. This report addresses these issues.
The rural areas we investigate also exhibit characteristics that could result in very severe
radiological accident impacts. The evacuation routes are limited, in some cases limited to one
highway. Blockage of an entire direction of evacuation due to a radioactive release would
significantly inhibit migration. Water supplies may be close to highways and railroads, creating
the possibility of contamination of drinking water. Emergency response capabilities are very
limited, compared to urban centers. In addition, the highway and railway characteristics in rural
areas may present conditions that allow greater release of radioactive materials, such as increased
travel speeds, steep grades and bare rock surfaces.
In this study, specific analyses of severe, yet credible highway and rail accidents at
specific locations within the State of Nevada are undertaken. Because of the uncertainty in the
mode of transportation to be ultimately used, as well as the vast demographic and geographic
differences among likely transportation corridors in Nevada, this study will provide separate
consequence assessments for 4 accident scenarios: A severe truck accident and a severe rail
accident involving the transportation of spent nuclear fuel through the metropolitan area of Las
Vegas, a severe truck accident in the town of West Wendover, near the Nevada-Utah border, and
a severe rail accident at the Carlin Tunnel, near the city of Carlin along the Union Pacific and
Southern Pacific railroads. At the heart of this study will be an estimation of the breadth and

9 The MGM Grand Hotel has 5,034 rooms. Assuming 2 persons per room, it could contain 10,000 guests at full occupancy.
According to the Las Vegas Sun (8/13/2000, ‘Casinos Compete for Job Hopping Workers, ‘ the MGM Grand has 8,000 employees.
This study assumes 25% of these employees are working at any given time.
10 Las Vegas Convention and Visitors Authority 2000 Executive Summary.
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Nevada Spent Fuel Transportation Severe Accident Analysis Page 3
depth of contamination under each scenario and an evaluation of the real ability and cost to
evacuate and decontaminate the exposed areas. These evaluations will necessarily focus on
different factors for the rural and urban areas.
We first must assess what is a credible accident at the specific chosen locations. In Las
Vegas, population densities might be high at specific potential accident locations, but vehicle
speeds may be low. That is, at certain locations, a potential accident might not be sufficiently
severe to lead to a release of radioactive particulates. Or, high impact accidents may be possible
at specific locations, but the population density may be low. In Section 1, we discuss the specific
locations we considered for potential accidents, and the type of accidents that are credible at
those locations. For each of these accidents, we discuss the radionuclide inventory that may be
released. In Section 2, we discuss the downwind radioactive particulate and gas concentrations
in air and surface concentrations of particulates. This information is used to estimate the
potential inhalation exposures to individuals outside and within buildings, and the direct gamma
dose rates due to deposited radionuclides. The information is also used to determine potential
remediation alternatives and economic costs. In Section 3 we discuss the specific situation in
Las Vegas for truck and train accidents. We estimate the population density in the tourist areas
of Las Vegas, and the health impact to visitors outside and within hotels. We also estimate the
surface concentrations inside and outside hotels and the effort and cost to decontaminate
horizontal (streets, sidewalks) and vertical (side of buildings) surfaces. This section also
investigates the ability to evacuate residents and visitors. In Section 4, we discuss the specific
situation for truck and train accidents in rural areas of Northern Nevada.
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