Going the Distance? The Safe Transport of Spent Nuclear Fuel and High-Level Radioactive Waste in the United States (2006) / Chapter Skim
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3 Transportation Risk
3 Transportation Risk
Pages 109-182
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From page 109... ...
It also includes social risks that arise from social processes1 and people's perceptions,2 even in the absence of radiation exposures. The health and safety risks and social risks are collectively referred to as societal risks in the statement of task given in Sidebar 1.1.
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From page 110... ...
The risks from spent nuclear fuel transport can be characterized by several measures. For example, risk can be expressed in terms of the expected number of deaths per quantity of spent fuel transported, per number of packages shipped, or per number of package shipments.
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From page 111... ...
Although the radiation doses to individuals near transport routes are likely to be very low, large numbers of individuals may receive exposures, producing a "collective dose" that can be used to estimate health impacts (see Sidebar 3.3)
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From page 112... ...
from being as a direct result of transportation packages transportation program operations Perception-based impacts: anxiety and associated illness; loss of property values; and reduced economic activity Accidents Health and environmental Direct socioeconomic impacts: impacts arising from elevated Temporary loss of transportation radiation and/or the physical route use and associated business release of radioactive material as disruptions such as a loss of a result of the degradation or tourism loss of package containment Perception-based impacts: social amplification of the normal impacts as a result of accidents; these can result in secondary or tertiary impacts, including stigmatization of people and places; loss of trust in transportation program management; moratorium on transportation program operations; and/or increased program costs result from any hazard, especially anthropogenic hazards that can be controlled through regulation. Society places a high value on human life and routinely demands that governments strictly regulate life-threatening hazards.
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From page 113... ...
In any case, spent fuel and high-level waste transportation programs are a very small component of the overall transport system for hazardous materials, as measured both by load mass and by volume of traffic. The committee provides an examination of health and safety risks of spent fuel and high-level waste transportation in Section 3.1.
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From page 114... ...
Radiation and radioactivity can be found in nature in a number of different forms. The natural radiation environment consists of cosmic and solar radiation, external radiation from radioactive materials present in rocks and soil, and inhaled 3.1 HEALTH AND SAFETY RISKS Two approaches are used in this section to estimate the health and safety risks of spent fuel and high-level waste transportation: (1)
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From page 115... ...
(2) an examination of the principal quantitative risk analyses that have been carried out for spent fuel and high-level waste transport, including the analysis for transporting spent fuel and high level-waste to a federal repository at Yucca Mountain, Nevada (Section 3.1.2)
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From page 116... ...
in the final Yucca Mountain Environmental Impact Statement (EIS)
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From page 117... ...
Most spent fuel transport across the nation's public highways and private railroads has involved small-quantity shipments of commercial spent fuel. Estimates of quantities of commercial spent fuel shipments are available from several sources.
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From page 118... ...
The federal repository and Private Fuel Storage, LLC, programs, for example, plan to ship about 20 and 13 times, respectively, the amount of commercial spent fuel that has been shipped in the United States since 1964. Moreover, both programs plan to ship spent fuel primarily by rail.
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From page 119... ...
Private carriers will keep records for those workers who use radiation monitoring devices in accordance with regulations, but these records are not published. Consequently, the doses received by workers and the public associated with spent nuclear fuel shipments in the United States are not precisely known, although the committee judges that they are likely to be relatively small given the external dose limits allowed by regulations combined with the small numbers of shipments that have been made to date.
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From page 120... ...
This is illustrated elsewhere in this chapter for the planned transportation program to a federal repository at Yucca Mountain. Information on accidents and incidents involving spent fuel shipments in the United States has been reported since the late 1940s.
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A summary of available data on transportation accidents and incidents is provided in Table 3.3. These data were compiled by DOE's Office of Civilian Radioactive Waste Management.
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From page 122... ...
Such surface contamination typically results from inadequate decontamination of packages following the loading of spent fuel.15 However, there is no confirmation of cause of contamination in the database. Table 3.4 provides a list of transportation accidents involving spent fuel transport packages between 1971 and 2005 in the United States.
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No release aThis table lists only accidents involving loaded and empty spent fuel packages; it does not include all of the incidents listed in Table 3.3. SOURCES: Weiner and Tenn (1999)
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From page 124... ...
. Moreover, a majority of the worldwide spent fuel shipments have been by rail, the preferred mode for shipping to Yucca Mountain and Private Fuel Storage.
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125 TRANSPORTATION RISK TABLE 3.5 Worldwide Spent Fuel Transportation Estimates Mass of Spent Number of Fuel Shipped Packages Shipping (MTHM) a Country of Origin Shipped Modes Destination Canada 100 187 Czech Republic 242 65 Rail To and from Slovakia Finland 233 65 Highway USSR or the and rail Russian Federation France Domestic 11,700 2,600 Mostly rail La Hague Other Europe 10,000 2,500 Mostly rail La Hague Japan 2,940 660 Sea and La Hague highway Germany >25 66 Highway Domestic and rail Hungary 258 72 Italy 81 52 Highway Domestic Japan 19951999 161 50 Sea and land Domestic 20002004 (proj.)
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From page 126... ...
This too is likely to be the case for spent fuel and high-level waste transport in the United States because many mainline rail routes pass through large cities. Some of the spent fuel being transported to La Hague and Sellafield is cooled for less than a year before being shipped.22 In contrast, current practice in the United States is to cool commercial spent fuel for at least five years before shipping it, and some of the spent fuel to be shipped to Yucca Mountain will have been cooled much longer than five years.23 Road and rail shipping distances to La Hague and Sellafield are generally 1000 kilometers (about 600 miles)
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From page 127... ...
There was a three-year moratorium on spent fuel shipments in these countries while the incidents were investigated and new procedures were put into place to eliminate the contamination problems. A subsequent investigation by regulatory authorities concluded that no workers or members of the public had received radiation doses exceeding the relevant regulatory limits as a consequence of these incidents (HSK, 1998)
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From page 128... ...
risks for transportation size of the transport of spent fuel and high-level program waste to Yucca Mountain, Nevada WASH-1238 Study (1972) The first analytical study of the health effects of spent fuel transportation in the United States was undertaken by the AEC in 1972 (AEC, 1972)
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From page 129... ...
The 1977 transportation EIS characterized environmental impacts in terms of fatalities, expressed as an annual probability of occurrence for two types of transport: incident-free transport, where the main health impact is expected to be cancer fatalities due to exposure of workers and the general public to small doses of radiation from the shipping containers; and accidents that produce either conventional traffic fatalities or, for more severe conditions, latent cancer fatalities resulting from the release of radioactive materials from a damaged transport package. Sandia National Laboratories performed this study.
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From page 130... ...
It can provide estimates of collective dose as well as doses to maximally exposed indi viduals. The code was first developed by Sandia National Laboratories for use in the 1977 transportation EIS (USNRC, 1977)
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From page 131... ...
Since the issuance of this EIS, the USNRC has sponsored two additional studies to improve its understanding of the risks from commercial spent nuclear fuel transportation by road and rail. Those studies are discussed in the following sections.
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25To place these numbers in perspective, consider that the planned transportation program to a federal repository at Yucca Mountain by the "mostly rail" scenario (described later in this chapter) would, according to DOE, involve about 9600 rail shipments and 1100 truck shipments (see Table 3.8)
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From page 133... ...
using updated models and data. Since this is the most current generic study and has been used as the basis for a more recent analysis of transportation to a Yucca Mountain repository, as discussed later in this chapter, it is described in some detail in this section.
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. One of the permanent repository sites considered was Yucca Mountain.
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From page 135... ...
Rollover 0.596 0.7584 Roadbed Non- 15.9981 22 0.3334 collision 0.7728 Ear th 31.9865 23 0.6666 Fire only 0.7300 24 0.0073 Obstruction, Other 5.7700 25 0.0577 FIGURE 3.1 Accident event trees for rail accidents from the 2000 reexamination study, slightly modified from the modal study (see Figure 2.3)
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From page 136... ...
. Surfaces along transportation routes (e.g., soils, concrete structures)
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Several sets of RADTRAN calculations were performed in this study: · Calculations for the 200 truck and 200 rail routes obtained by Monte Carlo sampling as described previously; · Calculations for 5 truck and 5 rail routes selected from the 1977 transportation EIS or from the 474 routes that connect spent fuel storage sites to the locations of the hypothetical interim storage facilities considered in this study -- the latter calculations were carried out to demonstrate that results for real routes would fall within the envelope of results for the representative 200 rail and 200 truck routes; · Calculations comparing the consequences and risks for RADTRAN 1 with RADTRAN 5 for a single transportation route; and · Calculations comparing the risks and consequences using the package inventories and assumptions about radionuclide releases developed for the 1977 transportation EIS, 1987 modal study, and this study. The study provided RADTRAN calculations for both incident-free and severe accident scenarios.
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From page 138... ...
Consequently, the overall results of the Sandia analyses are likely to be neither realistic nor bounding and probably overestimate the transport risks.29 One result is discussed below for the sake of illustration: Population risk estimates for severe accidents involving rail transport of PWR spent fuel in a steel-lead rail package. This example was selected because PWR fuel is the most common fuel used in U.S.
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From page 139... ...
, which is represented by the vertical distance between the 5th and 95th percentile compound CCDFs, reflects the sensitivity of the calculations to route characteristics (e.g., route length, wayside hardness, traffic conditions)
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From page 140... ...
The EIS considers two scenarios for transporting spent nuclear fuel and high-level radioactive waste from 72 commercial and 5 defense sites to the proposed repository at Yucca Mountain, Nevada: a mostly truck scenario that would involve transporting most of the spent fuel and high-level waste by legal-weight truck across the 30The mean collective dose risk is the collective dose that is received by the population from an accident times the probability of occurrence of that accident. This follows from the general risk equation, risk = probability x consequences, where consequences = collective dose.
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From page 141... ...
The first assumes that Yucca Mountain would receive the legislatively mandated limit of 70,000 metric tons of spent fuel and high-level waste over a period of 24 years. The second assumes that the repository would operate for 38 years and would receive between 119,000 and 125,000 metric tons of spent fuel, high-level radioactive waste, and other special requirements waste (e.g., greater-than-class-C waste)
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From page 142... ...
Repository capacity 70,000 (MTHM) Number of legal-weight truck shipments Commercial SNF 41,000 1100 DOE SNF 3500 DOE HLW 8300 Number of rail shipments Commercial SNF 300 7200 DOE SNF 770 DOE HLW 1700 Radiological Impacts, Routine Transporta Worker collective dose 29,000 79008800 Collective dose (person-rem)
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From page 143... ...
10.4 million people for mostly truck scenario and 16.4 million people for mostly rail scenario over 24 years Estimated number of 2.5 0.60.8 public latent cancer fatalities Total estimated number 14 3.84.3 of latent cancer fatalities Radiological Impacts, Maximally Reasonably Foreseeable Accident (MRFA) c Accident scenario Long-duration Long-duration fire that leads fire that leads to breach of a to breach of a package and package and dispersal of a dispersal of a portion of its portion of its contents contents Annual probability that 2.3 in 2.8 in During each year of the accident will occur 10 million 10 million the 24-year shipping campaign Dose to maximally 3 29 Maximally exposed exposed individual individuals are located assuming the accident downwind of the does occur (rem)
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From page 144... ...
Nonradiological Impacts Total fatalities from 6.8 3.14.2 vehicular collisions, industrial accidents, and air emissions NOTE: Numbers are rounded to two significant figures. aThe dose estimates shown in this section of the table have a probability of occurrence of 1; that is, it is certain that these doses would be received by workers and members of the public if the Yucca Mountain transportation program were carried out as described in Appendix J of the final Yucca Mountain EIS.
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From page 145... ...
DOE defines any accident that has the chance of occurring more than 1 in 10 million times per year as being reasonably foreseeable. The Final Yucca Mountain EIS analyses of maximally reasonably foreseeable accidents were based on an examination of the accident scenarios presented in the reexamination study (Sprung et al., 2000)
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From page 146... ...
Route selections were made for all but six sites that do not have the capacity to load or handle rail packages. 33However, as discussed in Chapter 5, the first fuel shipped to Yucca Mountain might not be thermally and radiologically cool.
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Table 3.8 provides a summary of the EIS analyses for Yucca Mountain for a 24-year transportation program involving the movement of 70,000 metric tons of spent fuel and high-level waste to the repository. The table provides several types of consequence estimates: · Estimates of radiation exposures during incident-free transport.
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From page 148... ...
This low probability is reflected in the small collective dose risk estimates shown in the table. The State of Nevada provided extensive commentary on the Yucca Mountain draft EIS estimates of transportation risk (Nevada, 2000)
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The committee has not performed an in-depth analysis of the methods used in the final Yucca Mountain EIS to estimate the radiological impacts shown in the table. The calculation of maximum incident-free impacts can be made if reliable data on shipments, routes, and populations can be obtained.
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From page 150... ...
Severe accidents involving loaded transportation packages might lead to the temporary loss of use of a transportation route, which could result in business disruptions and other inconveniences with economic and quality-of-life impacts. These direct socioeconomic impacts arise from generally well understood social processes.
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From page 151... ...
With respect to a spent fuel and high-level waste transportation program, risks might arise as follows. The advent of a program for transporting spent fuel and high-level waste -- perhaps even in the planning stages -- might produce im 37Another term used to describe these effects is "special impacts." Appendix N of the final EIS for Yucca Mountain (DOE, 2002a)
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From page 152... ...
, it is not surprising that the prospect or advent of a transport program through a community may widely be perceived to be threatening. The discernment of a threat posed by spent fuel and high-level waste shipments -- regardless of whether it is consistent with technical estimates of risk -- has real implications for affected individuals.
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From page 153... ...
. For spent fuel and high-level waste shipments, concern about stigma would be associated chiefly with severe accidents, but it could also result from frequent and widely publicized shipments or minor vehicular accidents involving spent fuel or high-level waste shipments.
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From page 154... ...
Most people recognize that transportation programs are run by fallible institutions and that institutional and human errors play a large role in determining transportation risks. There are many examples of technological systems where the experts were wrong or overly optimistic (SchraderFrechette, 1995; Perrow, 1999; Freudenburg, 2003)
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From page 155... ...
. A large body of published work has examined public perceptions concerning the proposed federal repository at Yucca Mountain, Nevada; much of the initial work was supported by the State of Nevada (e.g., Kasperson et al., 2001; see also, NRC, 1984; Slovic et al., 1991, 1994; Gregory et al., 1995)
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From page 156... ...
In addition, for any project with potentially adverse consequences, such as those that might result from the transportation of spent nuclear fuel and high-level waste, there are affected groups and vulnerable groups. Affected groups are all communities within an influence zone of a transportation project.
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From page 157... ...
Consequently, larger numbers of spent fuel and high-level waste shipments will pass through communities in that state than anywhere else in the country if a federal repository at Yucca Mountain is opened. Two surveys -- one of residents, the other of bankers and appraisers -- were undertaken by the Urban Environmental Institute, LLC (UER)
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From page 158... ...
Intertech Services Corporation completed a study for Lincoln County, Nevada, on the potential adverse impacts to Caliente, Nevada, from a Yucca Mountain transportation program (Intertech Services Corporation, 2001)
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From page 159... ...
A DOE-sponsored study of real estate transactions in South Carolina (Gawande and Jenkins-Smith, 2001) measured the effects of a series of highly publicized shipments of foreign spent fuel to the Savannah River Site (research reactor spent fuel shipments to the Savannah River Site are described in more detail in Chapter 4)
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From page 160... ...
· Risk perceptions may have gender, cultural, and ethnic predispositions. · Social risks are difficult to quantify and there are no universally agreed-upon metrics for comparing them.
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From page 161... ...
The committee's objective in presenting this comparison is to inform readers' understanding about the risks of spent fuel and high-level waste transportation, not to persuade readers that such risks are -- or are not-acceptable. The committee recognizes that acceptability is a normative judgment; that is, there is no basis in science for judging the acceptability of transportation risks.
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From page 162... ...
Other outcomes -- for example, those for the social risks described in Section 3.2 -- may be equally important, but data may be lacking to make meaningful comparisons.
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From page 163... ...
Thus, the committee separates comparisons of doses associated with routine radiological transport risks, which have the potential to provide chronic exposures, and severe accident risks, which have the potential to provide acute exposures. Risk estimates for cancer incidence and mortality from exposure to radiation and radionuclides are available (e.g., EPA, 1999; NRC, 2005a)
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From page 164... ...
This allowed the committee to compare cancer mortality from exposures to ionizing radiation in a spent fuel transportation accident with other types of hazardous material accidents -- for example, deaths from an accident involving releases of chlorine from a rail tanker car. The committee has used a wide range of comparison factors, some of which are more directly comparable than others.
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From page 165... ...
The most complete estimate of scenario-specific routine radiological risks for spent fuel and high-level waste transportation is provided by the planned Yucca Mountain transportation program. Those estimates, which are provided in the final Yucca Mountain EIS and described in Section 3.1.2, were used by the committee for some of the comparisons in this section.
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From page 166... ...
from transport of spent fuel and high-level waste to Yucca Mountain, approximately 4 million to 6 million would be expected to be diagnosed with solid cancers during their lifetimes for causes unrelated to the transportation program; about 2 million to 3.3 million of those cancers would be expected to be fatal. The estimated cancer fatalities from exposure to radiation during incident-free transport to Yucca Mountain -- one for the mostly rail scenario and about three for the mostly truck scenario-would not be detectable in this much larger population of fatal cancers.
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From page 167... ...
The exposures from spent fuel transport to a Yucca Mountain repository also will be largely involuntary for the individuals who receive them. Natural background radiation consists of cosmic and solar radiation, external radiation exposure from radioactive materials present in rocks and soil, and radioactivity that is inhaled or ingested (see Sidebar 3.2)
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From page 168... ...
Current DOE annual occupational administrative dose limit (DOE, 1999) All-pathways annual dose limit to reasonably maximally exposed individual near Yucca Mountain at time periods greater than 10,000 years after repository closure (70 FR 49014, August 22, 2005)
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annual natural 3 Includes doses from exposure to background radiation dose (300) radon (NCRP, 1987)
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From page 170... ...
Operations a Regulations b All-pathways annual dose limits for release of radiation to the environment from land disposal facilities (10 CFR Part 61) All-pathways annual dose limit to reasonably maximally exposed individual near Yucca Mountain for first 10,000 years after repository closure Approximate annual dose to maximally exposed resident near rail stop, mostly rail scenario (DOE, 2002a, Table 6-12)
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From page 171... ...
calculated using the CARI-6 Tokyo (Friedberg and computer program, which estimates Copeland, 2003) the effective dose of galactic cosmic radiation 0.12 Applies to maximally exposed (12)
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From page 172... ...
. There is also a qualitative difference between natural background radiation and radiation from a Yucca Mountain transportation program.
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First, according to analyses presented in the final Yucca Mountain EIS (DOE, 2002a) , maximally exposed workers (primarily transportation crews, escorts, and inspectors)
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From page 174... ...
Maximally exposed members of the public are estimated to receive substantially lower annual radiation doses from a Yucca Mountain transportation program as shown by the two bottom-most entries in the first column of the table. The maximally exposed resident near a rail stop (for the mostly rail scenario)
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The committee compared this mean CCDF to those for accidents involving rail transport of three other kinds of hazardous materials: a flammable liquid (methanol) , a flammable gas (propane)
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From page 176... ...
, and the population densities along the shipping routes were approximately the same for these three types of hazardous material shipments and the spent fuel shipments. The results should not be taken as exact estimates, but they are useful for comparison purposes.
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From page 177... ...
The mean CCDF for accidental releases of radioactive material from spent fuel packages has the same general shape as the CCDF for propane. However, the frequency of accidents that lead to such releases is expected to be four to five orders of magnitude lower because of the robust construction of the transportation packages.
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From page 178... ...
potential increases in radiation shine and release of radioactive materials from transport packages under accident conditions that are severe enough to compromise fuel element and package integrity. The radiological risks associated with the transportation of spent fuel and highlevel waste are well understood and are generally low, with the possible exception of risks from releases in extreme accidents involving very long duration, fully engulfing fires.
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From page 179... ...
Of course, spent fuel transportation is not risk-free, and past experience is not necessarily a useful predictor of future performance. The fact that spent fuel transportation risks have been low in the past does not necessarily mean that risks will also be low in the future.
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FINDING: The social risks for spent fuel and high-level waste transportation pose important challenges to the successful implementation of programs for transporting spent fuel and high-level waste in the United States. Such risks, which can result in lower property values along transportation routes, reductions in tourism, and increased anxiety, have received substantially less attention than health and safety risks, and some are difficult to characterize.
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From page 181... ...
This finding and recommendation spring from several factors: Social risk is a poorly understood phenomenon; expert opinion frequently differs; DOE does not, to the committee's knowledge, have any precedent to guide its understanding and management of social risks; and most transportation program staff are not likely to be well acquainted with either theory or practice on this issue. Consequently, the committee concluded that broad input and advice on social risks will be essential to the establishment and ultimate success of programs to transport spent fuel and high-level waste to a federal repository or interim storage.
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From page 182... ...
One of the most important functions of these advisory groups would be to foster continuous learning and improvement. The recommendation to expand the scope and membership of the TEC Working Group builds on and complements existing public participation and communication activities within DOE's transportation program for Yucca Mountain.
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