4.10 Intersite Transportation

4.10.1 Methodology

This PEIS evaluates the potential impacts from transporting special nuclear materials, hazardous wastes, and other weapons-related materials associated with the activities under consideration by the Stockpile Stewardship and Management Program. All materials shipped by DOE are first stabilized, then packed and shipped in accordance with all applicable Federal and state transportation regulatory requirements. In most cases, DOE requirements exceed DOT and NRC standards for commercial transport. Baseline information, the existing transportation patterns for each site, and the types of containers required to ship the materials have been included for this analysis, as appropriate.

Actual and projected inventories were used for the transportation analysis. Data already collected were used to the extent possible. Environmental impacts of transporting materials between facilities were estimated using a homogeneous population (i.e., urban, suburban, and rural), an average container or truckload of material, and a unit of measure (i.e., risk per kilometer) for each of the material forms. The assessment provides an overview comparison of transportation impacts for the alternatives being considered.

The estimated health risks in terms of potential total fatalities from transporting special nuclear material and radioactive material between the sites were quantitatively analyzed with the RADTRAN 4 computer code. Unit risk factors were developed for each type of special nuclear material and radioactive material to estimate the potential risk of transporting truckload shipments by DOE safe secure trailer over intersite routes or transporting shipments by air. These unit risk factors were used in conjunction with the quantity of material, form, distance, and number of shipments to estimate potential radiological and nonradiological impacts to the transport crew and public. The potential fatality impacts are presented for each alternative considered. The transportation of HE was evaluated qualitatively based on past shipping experience.

4.10.2 Affected Environment

The volume of DOE's hazardous material (radioactive and nonradioactive) shipments is extremely small in comparison to the volume of non-DOE hazardous materials shipments. DOT estimates that approximately 3.6 billion t (4 billion tons) of regulated hazardous materials are transported each year and that approximately 500,000 shipments of hazardous materials occur each day (PL 101-615, Section 2[1]). There are approximately 2 million shipments of radioactive materials, involving about 2.8 million packages, annually. This is about 2 percent of the Nation's total annual hazardous materials shipments. Most radioactive shipments involve small or intermediate quantities of material in relatively small packages. By comparison, the Complex ships about 6,200 radioactive packages (commercial and classified) between its sites, annually. This represents less than 0.3 percent of all radioactive shipments in the United States.

DOE's unclassified radioactive, HE, and other hazardous materials are transported by commercial carrier (truck, rail, or air). The hazardous and nonhazardous cargo shipped by commercial carriers to and from each of the alternative sites is described in appendix tables G.2-1, G.2-2, and G.2-3. Special nuclear materials, such as plutonium and HEU in the form of pits and secondaries included in this assessment, are transported by DOE-owned and -operated safe secure trailers. The safe secure trailers are vehicles designed specifically for the cargo's safety and security, and the special nuclear materials receive continual surveillance and accountability from DOE's Transportation Safeguards Division at Albuquerque, NM. Shipments by safe secure trailer are accompanied by armed guards and are monitored by a tracking system. Tritium components are transported by DOE's air cargo contractor.

HE is a nonradioactive, hazardous material. HE shipments must meet the standard shipping criteria established by DOT (49 CFR Subchapter C) and supplemented by state, local, and DOE regulations. These standards require the shipper to comply with selecting the proper, authorized packaging for the material; properly certifying what is being shipped; properly marking, labeling, loading, blocking, and bracing the material; and meeting safety requirements. HE is usually transported by commercial or Government truck (although DOE contract air shipments are allowed by DOT exemption).

4.10.2.1 Materials Transported Between Existing Sites (No Action)

Kansas City Plant. KCP produces nonnuclear components for nuclear weapons. These nonnuclear components are primarily transported from KCP to Pantex and SRS. A limited number of nonnuclear components are also shipped from KCP to LLNL and LANL for reliability testing. Nonnuclear components are transported by commercial truck.

Lawrence Livermore National Laboratory. LLNL performs nuclear weapons research, development, and testing (RD&T). LLNL also maintains a limited capability to fabricate plutonium components (pits), which are transported between sites by safe secure trailer. Presently, LLNL does not manufacture components for nuclear weapons. A limited amount of intersite transportation by commercial carriers, to or from LLNL, and the other DOE facilities is currently conducted to allow for research and testing needs. This transportation activity is unrelated to the direct weapons production activities.

Los Alamos National Laboratory. LANL performs nuclear weapons RD&T. Similar to LLNL, LANL also maintains a limited plutonium component (pit) fabrication capability. LANL currently produces and ships some nonnuclear components for nuclear weapons. Like LLNL, it does send and receive a limited number of weapons components to and from other DOE facilities by commercial carriers.

Nevada Test Site. NTS maintains the capability to conduct underground nuclear weapons testing and nonnuclear experiments. Nuclear weapons and fissile components to conduct such tests are transported by safe secure trailer from LLNL, LANL, and Pantex. Currently, there is no underground nuclear weapons testing. NTS has historically received LLW by truck from other DOE nuclear weapons sites, such as Pantex, for disposal. LLW is routinely transported to NTS from other DOE facilities by certified commercial truck carriers for disposal. NTS does not currently ship or receive nuclear weapon components for production, disposition, or testing.

Oak Ridge Reservation. The Y-12 Plant at ORR processes depleted uranium and HEU, and fabricates uranium components. Y-12 also produces lithium compounds and parts, provides precision machining and specialty subassembly of structural components, and provides storage for HEU. Y-12 ships secondaries to and receives secondaries from Pantex. A small number of secondaries are sometimes supplied to and from LLNL and LANL. HEU and secondaries and cases are transported by safe secure trailer. Other nonfissile components required by Y-12 are typically transported by commercial truck.

Pantex Plant. Pantex assembles and disassembles nuclear weapon components; performs weapons repair, modification, and disposal; conducts stockpile evaluation and testing; fabricates HE and nonnuclear components; and provides storage for plutonium in the form of pits. Fissile components such as pits, secondaries, or nuclear weapons are transported by safe secure trailer. Tritium reservoirs are transported between Pantex and SRS by air. HE and nonnuclear components are transported by commercial or Government truck. Pantex receives weapons from the stockpile for disassembly, uranium components from Y-12, tritium reservoirs from SRS, and nonnuclear components from KCP. Pantex ships nuclear weapons to the stockpile, uranium components to Y-12, tritium limited-life components to SRS, and LLW to NTS.

Sandia National Laboratories. Nonnuclear components for nuclear weapons systems are designed and engineered at SNL. SNL currently ships a limited number of nonnuclear weapons components to Pantex, LLNL, and LANL by commercial truck.

Savannah River Site. SRS recovers tritium from returned reservoirs, purifies the recovered tritium, and fills and surveys new and refurbished tritium reservoirs. SRS also stores a limited amount of weapons-grade plutonium. Under its current tritium recycling mission, SRS ships and receives tritium reservoirs to and from Pantex and DOD sites. Tritium reservoirs are transported almost exclusively by air. Plutonium is transported by safe secure trailer.

4.10.2.2 Site Transportation Interfaces for the Transport of Special Nuclear Materials

The existing transportation modes that serve each candidate site and the links to those modes for the intersite transport of special nuclear materials, weapon components, radioactive waste, and other hazardous materials are summarized in table 4.10.2.2-1.

Although hazardous materials could be transported by rail, truck, air, and barge, the materials discussed in this PEIS would normally be transported by truck or aircraft. Plutonium and HEU would be transported exclusively by DOE safe secure trailer. Tritium reservoirs would be transported by DOE contract air carrier. TRU waste and LLW would be transported by certified commercial truck carriers to licensed or permitted disposal facilities. It is unlikely that there would be any barge or rail shipments.

Table 4.10.2.2-1 also depicts the relative transportation ratings of the Stockpile Stewardship and Management Program alternative sites. This table was established using the rating methodology and evaluation procedures established by the Nuclear Weapons Complex Reconfiguration Site Panel and has been adapted for the stockpile stewardship and management alternatives.

Table 4.10.2.2-1.-- Transportation Modes and Comparison Ratings for the Candidate Sites

4.10.2.3 Packaging

Plutonium, HEU, and components containing tritium would always be transported in Type B packaging that meets stringent Nuclear Regulatory Commission (10 CFR) and DOT (49 CFR) requirements. Type B packaging is designed and tested to retain its containment and shielding properties in an accident. Thus, during normal operation, plutonium, HEU, or tritium-related transportation poses no significant risk to transportation workers or the public. Typical types of packagings used for stewardship and management materials are shown in table 4.10.2.3-1. Packaging is discussed further in appendix G.

Table 4.10.2.3-1.-- Types of Packaging for Stewardship and Management Materials

4.10.3 Environmental Consequences

Two kinds of intersite transportation of special nuclear materials are analyzed in this PEIS: the one-time relocation of strategic reserve materials and the transport of plutonium pits, canned subassemblies, and tritium reservoirs to support normal operation.

Under No Action, key weapons functions would continue to be performed at existing locations. These functions include pit storage and weapons A/D at Pantex, HEU storage and secondary and case fabrication at ORR, pit fabrication at LANL (in limited quantities), and production of tritium components at SRS. The combined annual radiological and nonradiological impacts from transporting pits, secondaries, and tritium components for normal operation (100 weapons per year) under No Action is estimated to be 3.33x10-3 fatalities per year (see table 4.10.3-2).

For the stockpile stewardship and management alternatives, the one-time relocation of the plutonium strategic reserve (pits) from storage at Pantex to storage at NTS and/or the relocation of the HEU strategic reserve secondaries from ORR to either NTS or Pantex could be required. The impact from transporting these materials was calculated using the RADTRAN computer code for standardized truckloads of material. The assumed truckloads consisted of 117 kg (256 lbs) of plutonium per truckload or 54 kg (119 lbs) of uranium per truckload. The annual impacts from transporting these materials are shown in table 4.10.3-1.

The transportation in support of normal operation would affect the individual sites as indicated below:

• The nonnuclear fabrication mission could remain at KCP with transportation requirements the same as No Action. Alternative sites to perform KCP's nonnuclear functions are LLNL, LANL, and SNL (many sites would absorb the mission).

Table 4.10.3-1.-- Annual Health Impacts from the One-Time Transportation of Strategic Reserve Materials

• Functions that could be relocated to LLNL are manufacturing secondary and case assemblies, nonnuclear components, and HE components. These functions would require the transport of nuclear components between LLNL and the A/D and/or the consolidated storage site and nonnuclear and HE components between LLNL and the A/D site.
• Functions that could be located at LANL would be fabricating pits, secondary and case assemblies, HE components, and nonnuclear components. These functions would require the transport of nuclear components between LANL and the A/D and/or the consolidated storage site and nonnuclear and HE components from LANL to the A/D site.
• NTS could be an alternative site to perform weapons A/D, which includes modifying existing plutonium pits, and could include storing the strategic reserve of plutonium and HEU. Placing the A/D function at NTS would require the shipment of weapon components (nuclear, nonnuclear, limited-life, and HE) between NTS and the pit and secondary and case fabrication, nonnuclear fabrication, HE fabrication, and the tritium recycling locations. It would also require the shipment of weapons to and from DOD facilities.
• The secondary and case fabrication mission could remain at ORR with transportation requirements the same as No Action. The alternative sites to fabricate ORR's fabrication of secondary and case assemblies are LLNL and LANL.
• The A/D and HE functions or the A/D function alone could remain at Pantex. If the A/D and HE functions remained, the transportation requirements would be the same as No Action except that the locations might change for primaries, secondaries, and nonnuclear components. Moving only the HE mission from Pantex would require shipping HE components and HE waste between Pantex and the new HE site or sites.
• SNL could be an alternative site for location of the majority of nonnuclear fabrication. This function would require shipping more nonnuclear weapon components to the A/D site.
• The function to fabricate pits could be reestablished at SRS. This would require the transportation of plutonium components between SRS and the A/D site and/or the plutonium storage site.

The Storage and Disposition PEIS is evaluating alternatives that could possibly move the plutonium strategic reserve from existing storage at Pantex to either Hanford, Idaho National Engineering Facility (INEL), NTS, ORR, or SRS, and the HEU strategic reserve from ORR to either Hanford, INEL, NTS, Pantex, or SRS. The one-time transport of materials to these potential consolidated storage locations is not addressed in this Stockpile Stewardship and Management PEIS. The impacts from the relocation of the strategic reserve pits from Pantex to NTS and the relocation of the strategic reserve secondaries from ORR to either NTS or Pantex under stockpile stewardship and management are presented in table 4.10.3-1. This section evaluates the potential impacts associated with the operational transportation requirements necessary to support the proposed management alternatives with storage at one of these storage and disposition sites.

Tritium reservoirs would continue to be recycled at SRS; thus, in the future these components would be transported between the A/D site (NTS or Pantex) and SRS. Tritium reservoirs would be transported by DOE contract air carrier.

If the A/D and HE missions remain collocated at Pantex (No Action), there would be no intersite transportation of HE, except for small quantities being shipped to LANL and LLNL for testing. If the HE mission is relocated, or if NTS is selected as the A/D site, an estimated 150 classified HE component shapes would be transported from either LLNL or LANL to Pantex, or from LLNL, LANL, or Pantex to NTS. In addition, HE waste material generated from the disassembly of weapons would be transported from the A/D Facility to the HE fabrication site.

Most of Pantex's shipments of HE material have been surplus material sold to commercial buyers. It is assumed surplus shipments would continue from a relocated HE mission (see appendix G for a description of HE shipments in 1994). Transporting HE component shapes is estimated to require approximately 12 round-trip shipments per year (the return leg would transport HE waste). There would be no impacts from normal (accident-free) transportation. The accident risk from transporting this material would be no greater than that encountered by the public from industry's transport of similar explosives. The HE accident impacts from transportation are bounded by the risk analyzed and presented in the facility accident sections.

For the alternatives under consideration, there are eight potential sites which could fabricate nuclear components, store strategic reserves of plutonium and uranium, recycle tritium, or perform A/D. All possible route combinations between these sites were evaluated to determine the potential impacts from transporting pits, secondaries, and tritium components for normal operation. The annual health risk for each potential combination of routes is described in appendix table G.1-1. Radiological and nonradiological and accident and accident-free risks are included.

There are 12 possible combinations of the stockpile stewardship and management alternatives for A/D, pit fabrication, and secondary and case fabrication. For each of these combinations, table 4.10.3-2 gives the annual health impact for the situation where strategic storage is collocated with the A/D function. In addition, taking into account the other possible consolidated storage locations considered in the Storage and Disposition Draft PEIS, table 4.10.3-3 gives the highest and lowest risk determined by the storage location for each possible combination of stockpile stewardship and management functions. Specific risks for all possible routes, including a breakout of accident and accident-free risks, are presented in appendix G.

In summary, annual transportation risk to support the activities required by the alternatives considered in this PEIS could range from 0.0154 to 2.85x10-3 fatalities. More detailed information is presented in appendix G. The route combinations required to support the alternatives considered in this PEIS are expected to increase upper and lower bound limits as follows:

• The maximum annual transportation health impact would be 0.0154, or approximately one additional fatality in 65 years. It is projected that this potential upper bound impact would result from the alternative which would require transporting pits from consolidated storage at Hanford to pit fabrication at SRS, then transporting them to weapons assembly at NTS; transporting secondaries from Hanford to secondary and case fabrication at ORR, then transporting them to weapons assembly at NTS; and transporting tritium reservoirs from SRS to weapons assembly at NTS.
• It is projected that the potential minimum annual transportation health impact would be 2.85x10-3 , or approximately one additional fatality in 351 years. This projected impact would result from selecting the alternative that would require transporting pits from storage at Pantex to pit fabrication at LANL, then transporting them to weapons assembly at Pantex; transporting secondaries from Pantex to secondary and case fabrication at LANL, then transporting them to weapons assembly at Pantex; and transporting tritium reservoirs from SRS to weapons assembly at Pantex.

Table 4.10.3-2.-- Summary of Annual Transportation Health Risk for Proposed Stockpile Stewardship and Management Alternatives

Table 4.10.3-3.-- High and Low Range of Annual Transportation Health Risk for All Possible Site Combinations (Strategic Storage Located at Any Site)

4.11 Next Generation Stockpile Stewardship Facilities

DOE recognizes that to be viable, its Stockpile Stewardship and Management Program must change over time to be responsive to national needs and the results of current research and evaluation activities. Accordingly, all facilities needed to fully implement the stockpile stewardship program over time cannot be fully identified at present. DOE has done some preliminary conceptual planning and research associated with the next generation of stockpile stewardship facilities, but is not yet able to define the facilities and/or their requirements sufficiently for decisionmaking. However, these next generation facilities can be defined in general terms at this time based on existing operating or proposed facilities such that broad environmental impacts can be discussed. These general impacts from construction and operation of such facilities are presented so that any significant cumulative environmental impacts that might be related to the ultimate science-based stockpile stewardship program can be identified in this PEIS and considered in the PEIS Record of Decision (ROD). At this time DOE has identified four potential facilities as next generation facilities for science-based stockpile stewardship: Advanced Hydrotest Facility (AHF), Advanced Radiation Source (ARS [X-1]), the Jupiter Facility, and High Explosive Pulsed Power Facility (HEPPF). The following section provides a broad description of what these proposed future facilities might look like and the types of environmental impacts associated with their construction and operation. In the future, DOE may choose to drop these concepts, expand upon them, or add to them. Any proposals would be subject to NEPA review prior to any decision to implement them.

Advanced Hydrotest Facility. AHF would be the next generation hydrodynamic test facility following the DARHT Facility at LANL. The AHF would be an improved radiographic facility that would provide for imaging on more than two axes, each with multiple time frames, though the number of axes and time frames is still subject to requirements definition and design evolution. The facility would be used to better reveal the evolution of weapon primaries implosion symmetry and boost-cavity shape under normal conditions and in accident scenarios. Due to the nature of the dynamic experiments and hydrodynamic testing to be conducted with the facility, AHF would probably be considered for location at NTS and LANL only.

At this point, the feasibility and definition of an AHF is still insufficiently determined for DOE to propose such a facility or adequately analyze it for the purposes of NEPA. For example, performance requirements and specifications for such a facility (i.e., determination of what capabilities should be required of an AHF for assessment of stockpile aging and related effects, beyond those of DARHT) have not been fully established. In addition, the type of technology to provide the basis for the facility has not been determined, and concepts for the resultant physical plant accordingly would vary significantly. Three basic technology approaches are currently being examined. These include linear induction accelerators of a type similar to that in the baseline DARHT Facility design (DOE/EIS-0228), an inductive-adder pulsed-power technology based on technology now in use for other purposes at SNL and elsewhere, and high-energy proton accelerators similar to technology in use at LANSCE and a number of facilities in the U.S. and internationally. The first two are different approaches to accelerating a high-current burst of electrons, which when stopped in a dense target produce x-rays for radiography. This is the approach used in the existing PHERMEX (LANL) and FXR (LLNL) facilities, and which will be used in DARHT. The third approach would use bursts of very energetic (approximately 20 billion-electron-volt) protons, magnetic lenses, and particle detectors to produce the radiographic image. These technologies still require development and validation.

It is likely that an AHF would require new building construction and considerable infrastructure (i.e., facilities, equipment, and personnel) in support of test events. Existing infrastructure at LANL or NTS might be used to the extent practical. The construction and operational requirements for AHF might be greater than that of the DARHT Facility. The impacts associated with construction and operation of facilities based on the different technology approaches could be significantly different. For example, the acreage required could be comparable to or somewhat larger than the 3.1 ha (9 acres) of land resources required for DARHT, but use of proton radiography could require an accelerator comparable in scale to the kilometer-long LANSCE or to other large accelerators operated by DOE. Based on information on the DARHT Facility, it is estimated that over 250 additional workers would be required for construction and operation of AHF. Construction and operation of AHF is not anticipated to use large quantities of water. New construction activities would be expected to result in an increase in short-term air emissions. Operation of AHF would be expected to have a minimal impact on the air quality considering the impacts projected for DARHT operations. AHF would not be expected to impact existing community infrastructure or services in the area; however, depending on the specific design, a proton accelerator could require significant electrical power resources. Waste volumes would not be expected to increase substantially over existing operations at LANL. Waste management associated with dynamic experiments with plutonium at NTS could require additional infrastructure.

To the extent the potential environmental impacts of an AHF can be forecast at this time, a significant part of the public and worker exposures and impacts due to normal operation of AHF would be those related to the conduct of hydrodynamic tests and dynamic experiments at the facility. While the impacts are inherently site-dependent, the hydrodynamic tests and dynamic experiments themselves can be anticipated to be similar to such activities as analyzed at DARHT in the DARHT Facility EIS (DOE/EIS-0228); therefore the DARHT Facility impacts are summarized here for reference. Population-based impacts may be expected to be lower at NTS. The normal radiological impacts of the DARHT Facility to the annual collective dose to the population residing within 80 km (50 mi) would be expected to be 0.57 person-rem. Latent cancer fatalities at this dose would not be expected. The maximum annual dose to any nearby resident would be about 2x10^-5rem with a corresponding latent cancer fatality of 1x10^-8 . The average annual dose to individual workers would probably not exceed 0.02 rem with a corresponding maximum probability of latent cancer fatality of 8x10-6 . Routine exposure to chemicals is expected to be low. The likelihood of a severe facility accident occurring would be very small. The population dose resulting from acute accidental release in the bounding facility accident, accidental uncontained detonation of a plutonium-containing assembly, evaluated on a what-if basis (related DOE safety studies indicate a probability of less than 10-6 per year), would be expected to range from 9,000 to 24,000 person-rem in the maximally exposed sector, based on 50th or 95th percentile atmospheric dispersion factors, respectively. Five to twelve latent cancer fatalities would [not] be expected from this dose. Population dose from acute accidental plutonium release from a containment breach was estimated to range from 210 to 560 person-rem, for which no latent cancer fatalities would be expected. For workers, the likelihood of a severe accident occurring and resulting in death would be minimized by a comprehensive training program and an explosives safety program.

Advanced Radiation Source (X-1) and Jupiter Facility. ARS (X-1) would be an advanced pulsed-power x-ray source that would provide enhanced capabilities in the areas of weapons physics, radiation science effects, and pulsed-power technology. SNL would be a principal candidate site because of its extensive expertise in this weapon physics and radiation effects technology and because the ARS (X-1) could probably utilize existing infrastructure associated with the Saturn Facility and Technical Area IV. The ARS (X-1) would likely require new building construction. The Saturn Facility accelerator is used as a nuclear weapon effects and weapon physics simulator with a large area and intense source of radiation. The Saturn Facility accelerator is designed to generate bremsstrahlung, x rays, and other electromagnetic radiation.

New construction activities for ARS (X-1) would be expected to result in an increase in short-term air emissions. The construction and operational requirements for the ARS (X-1) would be similar to those of the existing Saturn Facility. Operation of ARS (X-1) would be expected to have a minimal impact on the air quality of Albuquerque and the surrounding region considering the impacts resulting from operating the Saturn Facility. Based on Saturn Facility information, it is estimated that additional workers would be required for construction and operation of ARS (X-1). However, they would not be expected to impact existing community infrastructure or services in the area. Waste volumes would not increase substantially over existing operations. No radioactive materials would be expected to be produced or released from ARS (X-1). Materials handling and disposal of other wastes would serve to minimize the pollution and/or contamination risks.

Based on operation of the Saturn Facility, no significant risk to the public health and safety or to the environment would be expected from operation of ARS (X-1). Offsite impacts to the environment would be expected to be negligible or nonexistent. Onsite personnel exposures would be expected to be below 0.1 rem/yr and site boundary annual exposure would most likely be undetectable. Employee risk from industrial accidents during operation of ARS (X-1) would be identified and reduced to a level that is as low as reasonably achievable for the facility.

The Jupiter Facility would be a next generation facility well beyond ARS (X-1). It is not expected to have any significant or unusual environmental impacts based on the similar types of experiments and technology involved.

High Explosives Pulsed Power Facility. HEPPF, a potential next-generation facility, would be a possible follow-on HE firing site, configured specially for HE-driven pulsed power experiments, beyond the existing capabilities in the Complex to support such experiments. These experiments would, for example, study physics related to weapons secondary at shock pressures and velocities approaching those of actual weapon conditions.

DOE has pursued the application of electrical pulsed power on the microsecond time scale to weapons research since the 1960s. This R&D program has involved HE pulsed-power generators of various types, which have been used at existing HE firing sites in the Complex, in addition to fixed-facility capacitor banks such as Pegasus II at LANL and the proposed Atlas Facility. HE generators are used to explore higher energy (higher current) frontiers than may be available in existing fixed facilities without major capital investment, albeit at a relatively low data rate, and capacitor banks provide repeatable (and indoor) experimental facilities with higher data rates, for broad experimental use. These activities are programmatically complementary aspects of R&D (appendix K considers reliance on explosive-driven pulsed-power experiments and discusses why this is not a reasonable alternative to Atlas). Ongoing HE pulsed-power experiments are conducted for pulsed-power technology R&D, for weapons stockpile stewardship applications, and for unclassified scientific collaborations including those with Russian and other foreign scientists.

A variety of HE pulsed-power generator types are used in experiments. These generators are one-time-use assemblies of HE and metal and other components (commonly copper, structural materials such as aluminum, steel, and plastic, and possibly other materials depending on the experiment). When detonated, the explosive motion of the assemblies acts as an electrical generator to produce a large current, which is delivered to an experimental configuration. High magnetic fields result from the current pulse. In principle, such experiments can be performed at any appropriately equipped firing location, of which there are many in routine use at the DOE stockpile stewardship sites, within environmental limits and the structural design limits of the individual firing site. However, some HE firing sites (e.g., at TA-39 at LANL) have been specially configured to support these HE pulsed-power experiments; a principal firing site at TA-39 has within its bunker a capacitor bank to provide the seed electrical current for the HE pulsed-power generators. Currently, most of the largest-scale HE pulsed-power experiments in the United States are conducted at this LANL location. The highest-current generator design presently in routine use in the United States is called Procyon, and is about 3 m (10 ft) in length. Impacts of these ongoing R&D activities are included in the cumulative impacts for the No Action alternative in this PEIS.

HEPPF, as conceptualized, would be specially designed to support HE pulsed-power experiments of larger scale and of greater complexity in support of the stockpile stewardship mission: for example, to support generators using much larger explosive charges, which though not yet fully demonstrated for experiments, could produce higher pressures in larger masses and volumes than can be accessed at the LANL site. HEPPF would probably be sited at NTS because of the amount of HE and because an existing infrastructure is already available. Since the idea of a new HEPPF was first conceived some years ago, Big Explosives Experimental Facility (BEEF) has been separately developed as a firing site at NTS, based on refurbished bunkers originally developed for atmospheric nuclear tests. Although BEEF does not have specially configured HE pulsed power like the principal LANL firing site, in its current configuration BEEF is suitable for a variety of HE experiments, including many pulsed-power technology experiments. Experiments related to such purposes have been part of recent qualification tests. Therefore it may be possible to make modifications to BEEF when the need for and definition of such modifications is clear, to satisfy any future need for a new HEPPF.

BEEF is located in north-central Area 4 of Yucca Flat. BEEF comprises Bunkers 4-300 and 4-480, which house modern test equipment for use during detonations of very large, conventional HE charges and devices. Bunker 4-300 contains the control room, the laser room, and the utility room. The control and utility rooms were modified to house the diagnostic and firing control electronics, digitizers, electronic recording equipment, and other electronic equipment necessary for hydrodynamic and pulsed power experiments. The laser room was modified to accommodate a pulsed Ruby laser for image-converter camera illumination and a laser for multibeam Fabry-Perot velocimetry. Bunker 4-480 is designed to contain up to five helium or nitrogen-gas-driven rotating-mirror framing cameras and five optical ports with access to the gravel firing pad. The area surrounding the bunkers is graded with new earthen berms which provide blast protection, shield from radiation, and serve as a downrange projectile stop.

BEEF contains a firing table approximately 20x20 m (66x66 ft), consisting of pea gravel 1.8 m (6 ft) to 2.4 m (8 ft) deep, within the graded area west of the bunkers. Three large steel cylinders (3 m [10 ft] in diameter and 6 m [20 ft] long) are placed outside the bunkers near the firing pad to house 2.3-million-electron volt Febetron x-ray sources for high-energy x-ray radiography. As at other firing sites, among the HE experiments that can be performed at BEEF are pulsed-power-generating experiments. The facility has the capability to support many of the sophisticated diagnostic techniques needed for the evaluation of hydrodynamic and pulsed-power experiments containing large amounts of HE. Analysis of the impacts of operating the existing BEEF for explosive experiments, including those that involve pulsed-power technology, is incorporated in the NTS EIS (DOE/EIS 0243). These impacts are also included in cumulative impacts for the No Action alternative in this PEIS.

Should a need for HEPPF be determined, existing infrastructure at NTS would be used, to the extent practical, to develop the facility. Definition of the required modifications and additions is not yet mature enough to support environmental analysis in this PEIS. However, modifications to BEEF could include construction of additional bunker/shelter space near the firing location. The additional bunker space could be reinforced concrete construction, buried or earth covered in a manner virtually identical to Bunkers 4-300 and 4-480. In addition, future experiments conducted at HEPPF may require recording of a large number (several hundred) of channels of electronic and optical data. An expanded, suitably sheltered recording station also may be required. Additional shelters and blast-shields may be temporary or permanent and constructed of native soil to form earth berms or steel and sandbags to form structures. Upgrading construction activities would be expected to result in an increase in short-term air emissions.

Additional workers would be required for construction; however, for operation, the number of workers would be expected to be similar to that of BEEF. Operation of HEPPF would be expected to have minimal impact on the air quality of Clark County and the surrounding region considering the impacts projected for BEEF operations. HEPPF would not be expected to impact existing community infrastructure or services in the area.

Based on the operation of BEEF as analyzed in the NTS EIS, no significant risk to workers, to the public health and safety, or to the environment would be expected for HEPPF. Offsite impacts to the environment would be expected to be negligible or nonexistent.

4.12 Environmental Impacts of Underground Nuclear Testing

The last underground nuclear test was conducted in the United States in 1992. Since then, the Nation has been observing a moratorium on underground nuclear testing while pursuing a Comprehensive Test Ban Treaty (CTBT). On August 11, 1995, the President announced that, "one of my Administration's highest priorities is to negotiate a Comprehensive Test Ban Treaty to reduce the danger posed by nuclear weapons proliferation." In this announcement, the President also stated that he would seek a "zero-yield" CTBT, which would "ban any nuclear weapon test explosion or any other nuclear explosion immediately upon entry into force." The President declared his commitment "to do everything possible to conclude the Comprehensive Test Ban Treaty negotiations as soon as possible so that a treaty can be signed next year."

As part of this announcement, the President also stated that he had been assured "that we can meet the challenge of maintaining our nuclear deterrent under a Comprehensive Test Ban Treaty through a science-based Stockpile Stewardship Program without nuclear testing." However, the President cautioned that, "while I am optimistic that the Stockpile Stewardship Program will be successful, as President I cannot dismiss the possibility, however unlikely, that the program will fall short of its objectives." The President went on further to say that, "In the event that I were informed by the Secretary of Defense and Secretary of Energy...that a high level of confidence in the safety or reliability of a nuclear weapons type which the two Secretaries consider to be critical to our nuclear deterrent could no longer be certified, I would be prepared, in consultation with Congress, to exercise our `supreme national interests' rights under the Comprehensive Test Ban Treaty in order to conduct whatever testing might be required."

One of the primary purposes of the Stockpile Stewardship and Management PEIS is to evaluate ways of maintaining a continued safe and reliable nuclear deterrent in the absence of nuclear testing. Thus, the proposal described in chapter 3 of this PEIS does not include nuclear testing. However, because it is possible--although not probable--that under the CTBT the United States might one day exercise its "supreme national interests" rights to conduct underground nuclear testing to certify the safety and reliability of its nuclear weapons, the following programmatic evaluation of the environmental impacts of underground nuclear testing at NTS is provided. More detailed information on the environmental impacts of underground nuclear testing is contained in the Environmental Impact Statement for the Nevada Test Site and Off-site Locations in the State of Nevada (DOE/EIS 0243, 1996).

The various steps involved in conducting an underground nuclear test are summarized below to provide an overview to the reader, and to aid in understanding the potential environmental impacts associated with underground nuclear testing. (For other descriptions of the testing process, see NT USGS 1994a; OTA 1989a). Variations to this general description will occur based on which national laboratories performs the weapon emplacement and testing.

• In recent years, emplacement holes were drilled using mud or detergent and water and a dual-string reverse-circulation method. This method replaced the conventional circulation method that used bentonite or sepiolite mud. Steel casing is installed and extends 9 to 30 m (30 to 98 ft) from the surface. If the test point is below the static water level, a liner is also installed in the bottom of the emplacement hole, and the emplacement hole is dewatered. Otherwise, no liner is installed. Cement grout is placed around the casing and liner.
• Each test includes a test rack made of steel that is used to support the nuclear device and the various instruments and detectors used to measure test results. Typically, racks are more than 30 m (98 ft) in height and include from 2 to as many as 20 line-of-sight pipes, each with a window of a composition compatible with the desired measurement. The rack sits on top of a steel canister that contains the nuclear device.
• The canister is often lined with a mixture of boron and polyethylene. Large quantities of polyethylene are used on the racks. Other organic materials used include polyvinyl chloride, TeflonTM, polystyrene, phenolic, and neoprene. Complex fluorescing compounds and laser dyes are used as part of some detectors. Typically, tens of tons of lead are used to shield both the canister and the rack. Copper is used for wiring and other purposes. Beryllium, nickel, and zinc may be present in small quantities in detector packages. Arsenic, chromium, cadmium, osmium, and thallium have been used in rare instances. Other commonly used metals include tungsten, tantalum, stainless steel (iron, chromium, and nickel), and aluminum.
• Each test device contains nuclear materials, such as uranium, plutonium, tritium, lithium, and structural materials, such as steel, aluminum, beryllium, and gold. Radiochemical detectors (for example, yttrium, zirconium, thulium, and lutetium) and tracers (isotopes of uranium, plutonium, americium, or curium) are also used. The detectors and tracers are generally less than 100-g (3.5-oz) quantities.
• Magnetite powder is poured downhole to cover the sides and top of the rack. This naturally occurring mineral contains thorium and a variety of other impurities. Stemming materials are used to prevent the escape of radioactivity from the device upwards in the emplacement hole. Stemming materials consist of layers of coarse gravel with layers of fine gravel, sand, or bentonite. The gravel and sand are native materials. Two or more plugs made of two-part epoxy, coal-tar epoxy, sanded gypsum concrete, or sanded gypsum aggregate are placed in the hole, well above the cavity formed by the detonation, and remain intact after the test.
• As shown in figure 4.12-1, Stage I, the explosion initially creates a nearly spherical cavity filled with gases that are formed by atomization and vaporization of materials from the explosive device and its immediate surroundings. The molten cavity walls subsequently flow down to form a puddle that is vitrified as a result of quenching during condensation of the cavity gases as the cavity cools (Stage II). As gas pressure decreases, the rock above the cavity generally falls into the cavity with rubble (Stage III); this chimney-forming process may proceed upward all the way to the surface to form a crater, or it may stop at some intermediate point (Stage IV). Vaporized material is condensed and incorporated into molten rock or escapes into the chimney rubble where it may condense on solid rock. Volatile elements or materials tend to be enriched in the rubble zone, whereas refractory materials tend to remain in the puddle glass.

• The melt zone created by the nuclear test incorporates a mass (expressed in tons) of the same order of magnitude as the device yield (expressed in tons); the zone would extend well beyond the top of a 30-m (98-ft) rack if the yield was about 100 kt or more. In every test with a significant nuclear-energy release, the entire device is atomized and mixed with a relatively large quantity of rock.
• Reentry holes are typically drilled at an angle directed to intercept the test debris and puddle glass near its center. A profile of the radioactive material along the hole is measured with a downhole Geiger counter, and then samples of the puddle glass are collected using a sidewall sampler. The drilling procedure uses drilling mud with various additives, and a significant fraction of the mud is generally lost downhole into the highly permeable structure of the rubble created by the test. LLNL uses air foam for the upper part of the drill-back hole and drilling mud for the lower part of the hole.

The consequences of underground testing on the environment of the NTS can be evaluated on the basis of past testing actions. Through 1992, there have been 928 announced nuclear detonations on the NTS; 828 of these tests were underground tests. In general, the effects of underground testing that have occurred in the past, and those to be anticipated in the future, include impacts to land, geology, water resources, biotic, air quality, radiological and human health, and transportation. Each of these resource areas is discussed below.

Land. As shown in figure 4.12-2, underground nuclear testing would likely be conducted in the Yucca Flats, Painted Mesa, or Rainer Mesa Areas that are designated as the Nuclear Test Zone. Including a buffer zone, each underground nuclear test requires approximately 16 ha (40 acres). Approximately 5 ha (12 acres) of surface geologic media are disturbed in each underground nuclear test in Yucca Flat (Data Sheets, 1995). Radii of cavities at NTS range up to about 50 m (160 ft), and rubble chimneys range from up to about 50 m (160 ft) to about 350 m (1,150 ft) high (NT LLNL 1976a).

Because the land designated as the Nuclear Test Zone encompasses several hundred thousand hectares, the amount of potentially affected land would be a relatively small percentage (less than 1 percent). Additionally, underground testing would be a compatible use of the land; therefore, a change in land-use designation would not be required.

The formation of underground cavities and subsidence craters, as a result of underground testing, represent an unavoidable impact on the land in the vicinity of the planned tests. However, there are already hundreds of such cavities and craters on NTS.

Geology. Potential impacts on geological resources include fault reactivation and associated seismicity induced by underground testing of nuclear devices, offsite disturbances, and onsite radiological contamination of geological media. Fault reactivation from testing of nuclear devices disturbs subsurface and surface geologic media, which is potentially significant in terms of resultant limitations on land use or resultant changes in surface and subsurface water movement. Ground-motion studies have played a large role in the weapons testing program. SNL has developed a program for recording surface and subsurface motions resulting from underground nuclear explosions (SNL 1979a; SNL 1982b). There are several factors that influence the level and duration of ground motion from underground explosions, including yield of the device; ground-coupling at the source of explosion, which is a function of depth of the device, local geology, and stratigraphy; geological complexity along the transmission path; and the topography and geology at the location receiving ground motion. There is always some variation or unknown associated with estimating these factors; but, because of the long history of conducting weapon tests, the effects are reasonably predictable.

The yield or size of underground nuclear explosions is limited by the Limited Test Ban Treaty to a maximum HE equivalent of 150 kt. For the purposes of this evaluation, all future weapons testing is assumed to occur under this limitation. Historically, most underground nuclear testing has been conducted in the Paihute Mesa and Yucca Flat areas. Because geologic structure may differ considerably among the testing areas, effects of tests in the unused areas are uncertain. Nevertheless, the geographic areas for testing and the yield limits can be used to estimate ground-motion effects from future weapons tests.

Ground-motion hazards can result from the underground nuclear explosion and secondary seismic effects. Because of the rather complete recording of ground motions emanating from NTS activities, the effects of the weapons testing program are predictable, and damage effects have been documented. Communities within about 48 km (30 mi) of testing areas that could be most affected by ground motion from underground nuclear explosions are Beatty, Amargosa Valley, and Indian Springs. The closest potential testing areas for these communities are 31 to 40 km (19 to 25 mi) away. Table 4.12-1 is a tabulation of peak horizontal ground-motions for 150-kiloton tests at 31 km (19 mi) away, using regressions developed by Long (NT SNL 1986a). Peak ground acceleration, velocity, and displacement were computed at the 50th and 84th percentiles of the log-normal distributions given by Long (NT SNL 1986a) for rock and alluvium recording geology at 31 km (19 mi) for 150 kt tests. Expected peak ground accelerations are well below 0.05, which is the acceleration where slight damage might occur in typical buildings less than several stories in height.

Table 4.12-1.-- Predicted (50th and 84th Percentiles) Peak Ground Motions at Localities 31 Kilometers (19 Miles) from Underground Testing Areas

Data pertaining to offsite damage support conclusions based on expected motion. Since the Threshold Test Ban Treaty, only a few reports of damage to local communities occur each year, and these are of a very minor nature. Beyond about 48 km (30 mi), structures would have to be higher than several stories tall before they would be affected. The closest location where structures of that height are located is in Las Vegas. A smaller number of similar complaints have been recorded from people in Las Vegas high-rise structures.

Several Nye County mines are located in the testing vicinity, but all are at a distance greater than 40 km (25 mi) from the closest potential testing area. Because the distances from these mines to the underground nuclear explosions are approximately the same as, or greater than, the distances for communities, damage to structures in the mines is not expected. In investigations of earthquake effects to mines (Owen 1981a), there are very few reports of damage. Surveys of mines in the vicinity of NTS by Owen and Scholl further support these findings (NT ERDA 1977a).

In addition to direct ground motion effects of underground nuclear explosions, there is also a potential hazard from secondary seismic effects. Secondary effects are associated with co-seismic strain release attributed to release of tectonic strain, aftershocks that can be associated with tectonic strain release, and events associated with the collapse of cavities created by the underground nuclear explosions. Beyond 5 to 10 km (3 to 6 mi) of even the largest, pre-Limited Test Ban Treaty underground nuclear explosion (greater than 1 megaton), there was no evidence of significant secondary seismic effects associated with testing, and in no case has the magnitude of an aftershock been larger than the magnitude of the underground nuclear explosion (NT SNL 1986b).

Underground conventional HE, hydrodynamic, and hydronuclear experiments would produce some of the physical effects on geologic media and processes associated with underground tests of nuclear devices (e.g., compression and fracturing). These effects are anticipated to be significant and irrevocable although small in relation to the effects of detonation of nuclear devices.

In addition to the direct effect on geologic media and processes of detonating nuclear and other devices, preparation for such tests also disturbs geologic media. Disturbances include any associated infrastructure, excavated tunnels, and an inventory of deep boreholes up to 3.6 m (11.8 ft) in diameter for detonation of nuclear devices. Geologic media excavated in tunnels, boreholes, and borrow pits are considered to be permanently lost. Excavation of tunnels and any testing conducted in those tunnels potentially could impact slope stability.

During an underground detonation, large quantities of neutrons are released. Naturally occurring materials in the host rock, such as iron, lead, and zinc, capture some of these neutrons. The result is the formation of unstable radioactive nuclei. The majority of atoms in the host rock occur in a stable form; the activation products that are generated are considered part of the total release from a test. Radioisotope contamination might extend up to five cavity radii from the point of detonation where radioactivity has been released into the geologic media. However, most of the radioactive materials that are created during an underground nuclear explosion are expected to be trapped within a pocket of resolidified rock melt in the explosion cavity. Radioactive noble gases and tritium may be released to the surface by gradual seepage from the cavities and by escape of gases during sampling operations. The effects of subsidence and the confined radioactivity on the environment will persist for many years.

Water Resources. Because underground nuclear testing does not utilize any significant amount of groundwater, it is unlikely that there would be any potential to impact groundwater availability. However, as an unavoidable consequence of underground nuclear testing, the quality of the groundwater under some portions of NTS has been affected. If any underground tests were to be detonated under or near the water table, additional impacts to water quality could be expected.

The effects of underground testing have been well documented (NT LLNL 1976a), and the hazardous materials associated with testing have been detailed by Bryant (NT DOE 1996c). The potential for a given test event to result in groundwater contamination is a function of the yield of the test device and its location relative to the water table.

The types of contaminants related to active testing include four major categories of radionuclides and hazardous substances: source term and fission products, activation products, stemming material, and ancillary operations that use radioactive or hazardous substances. The exact quantity of substances that are released during a given test is unknown, but can be approximated based upon the similarity in materials used and in the overall testing procedures.

Information concerning releases from a test is summarized in Borg et. al. (NT LLNL 1976a) and Glasstone (DOD 1962a). The source term that is released during a test includes the original nuclear material that did not undergo reaction during detonation. The fission products are those direct products generated as a consequence of the detonation. About 80 different fission products result from the fission of a given nuclear detonation, and about 200 different isotopes of 36 elements can be formed through their decay into a complex mixture of daughter products. There are also 3 specific source-term radionuclides (tritium, plutonium, and uranium) and 24 specific fission products that result from a typical nuclear test. The estimated total release of fission and source-term radionuclides and activation products is 804,500 curies per kiloton.

Another source of contamination from underground testing is from the use of stemming materials. For most tests, significant quantities of nonradioactive materials are emplaced underground, along with the nuclear device, and are collectively termed stemming materials. For a typical test, at least 59,000 kg (130,000 lb) of rack and stemming materials are placed underground (NT DOE 1996c). Lead is by far the major hazardous constituent at about 450 kg (1,000 lb) per test. Small quantities (less than 0.5 kg [1 lb] each) of arsenic, beryllium, naphthalene, and zinc are also commonly present in the stemming materials.

Because test yields and the location and proximity to the water table of any tests that might be conducted have not been defined, it is not possible to estimate the total potential releases to the groundwater. If any tests are conducted in or near the water table, then significant releases to the groundwater are to be expected. If any tests are conducted in or near the water table, then significant releases of radionuclides and hazardous materials into the near test environment are to be expected. Tests conducted well above the water table would release significant quantities of radionuclides and hazardous materials into the unsaturated zone. Some downward migration of these contaminants might occur and might have the potential to contaminate the underlying groundwater.

The ancillary operations related to testing are primarily surface based and have little potential for groundwater contamination. Minor quantities of drilling fluids or lost circulation materials might be introduced into the near-water-table environment during test hole drilling and postshot drill-back operations. Any contamination that results from these activities would be considered inconsequential compared to the releases from the actual test.

It is difficult to predict the significance of the releases from underground testing on the water resources of NTS. Perhaps the best gauge can be made based upon the results of past testing activities. There have been 111 tests conducted under the water table and 124 tests where the lower shot cavity was under, or within 75 m (250 ft) of the water table. The combined yield of the tests conducted under the water table and tests with cavities that extended below the water table was 28 megatons.

The results of the Long Term Hydrology Monitoring Program and research into tritium migration have found that the migration of radionuclides beyond the near test environment is rare. Instances have been found where radionuclides have moved through fracture injection at the time of the test (NT DOE 1996c). Tritium migration via groundwater flow has been confirmed, but in the more than 30 years that underground testing has been done, no offsite releases of tritium in the groundwater have been detected.

Underground testing would be expected to have a significant impact on groundwater quality only if the testing is conducted in, or near, the water table. In this event, large scale contamination of the near-test groundwater resources could occur. However, because of the conditions at NTS (low hydraulic conductivities, high absorption geologic media, and slight hydraulic gradients), it is not considered likely that any significant impacts would occur in areas downgradient of the underground testing locations.

Biotic Resources. Because DOE has already prepared sufficient sites to handle numerous underground tests, no new impacts on biological resources would arise from preparation for these tests. A subsidence crater would be created by the underground test of the nuclear device. Because this crater would form in the area disturbed during site preparation for the test, no new loss of habitat would occur. Underground testing might impact individuals of recreational important species, such as waterfowl and doves, and candidate species of bats and birds, as they would be exposed to drilling fluid in drilling sumps constructed during postshot operations. Exposure to drilling fluid additives might increase these organisms' probability of drowning (NT DOE 1996c). The impact would not be large enough to decrease offsite recreational opportunities.

Hazardous or radioactive material releases could cause the mortality of plants and animals over tens or hundreds of hectares (NT DOE 1996c). This could have a significant impact on the viability of rare plants found in the northern half of NTS. However, because past aboveground tests and vented underground tests have not caused the expiration of any species from NTS, it is unlikely that future accidental venting would have that effect.

Because nuclear tests are conducted north of the range of the desert tortoise and because these tests normally are conducted when the wind is blowing to the north or northeast, accidental venting should not impact this threatened species (DOD 1977a; NT DOE 1995i). Additional releases of tritium into the aquifer from the underground nuclear test would not likely increase the impact to threatened and endangered species located at Devils Hole National Monument or Ash Meadows National Wildlife Refuge, given the short half-life of tritium and the slow rate of water exchange between the nuclear test sites and those springs (GTI 1995a; NT LLNL 1976a). Transportation to study sites would be infrequent enough as to not significantly increase the impact of this program on biological resources.

Air Quality. The average, annual fugitive dust emission rate (PM₁₀), including various drilling and construction activities, is about 1,290 t (1,422 tons). These emissions represent 0.16 percent of the total Nye County fugitive emissions. Fugitive dust calculations assume a 50-percent reduction as a result of watering the sites. As construction activities are only expected to occur on a short-term basis, long-term air quality impacts are not expected. Nevada Administrative Code 445B.365 regulates fugitive dust from surface disturbance of 2 ha (5 acres) or more. DOE has current Operating Permit 2743, which expires March 1998, for variable disturbance of land at NTS. If any radioactive noble gases and tritium were released to the surface by gradual seepage from the cavities or by escape during sampling operations, such releases are expected to be so small that impacts would be negligible.

Radiological and Human Health. Potential exposures of workers are possible during the tests conducted as part of the underground nuclear testing. The human health effects due to these exposures are based on an average annual dose reported in the NTS Site-Wide EIS (DOE/EIS 0243), with the results included in table 4.12-2.

Potential accidental releases from underground nuclear weapons testing were determined based on historical information from past testing at the site. These effects are also included in table 4.12-2.

Should DOE be directed by the President to conduct underground nuclear-yield testing under Alternative 1 of the NTS Site-Wide EIS, the probability of a single latent cancer fatality in the offsite population being caused as a result of radiological accidents over the 10 years evaluated by the EIS would be about 0.0055 (about one in 180). The probability of any other detrimental health effect occurring in the offsite population would be about 0.0025 (about one in 400).

Device delivery and assembly, as part of the underground nuclear weapons testing, are conducted at the Device Assembly Facility. Accident analyses performed as part of the Device Assembly Facility SAR show that for various design basis and operational accident scenarios considered, the impacts in terms of latent cancer fatalities fall well below the nuclear safety goal. All device assembly facility risk estimates are based on the SAR for the Device Assembly Facility. Section 4.9.3.9 of this PEIS discusses potential impacts associated with accidents at the Device Assembly Facility.

Transportation. DOE evaluated and reported the risks (consequences and probabilities) associated with transporting DP materials in SNL's Defense Programs Transportation Risk Assessment: Probabilities and Consequences of Accidental Dispersal of Radioactive Material Arising from Off-Site Transportation of Defense Programs Material (U) (SAND93-1617, September 1994). In that study, the annual risk of shipments of various cargos was evaluated based on many factors, including, but not limited to the transportation mode, how often and how far each cargo must be shipped, the specific route, and the population density along specific routes.

Table 4.12-2.-- Human Health Risks and Safety Impacts from Underground Nuclear Testing

Detailed information relating to methods and assumptions used for the risk analysis of DP materials is provided in appendix B of the transportation study. The results of the risk analysis indicate a very low potential for accidents; data analyzed from fiscal year 1984 through 1993 yielded an estimated 6.6 accidents per 161 million km (100 million mi). The risk of latent cancer fatalities (total to members of the public) and radiation detriment are significantly lower than the risk of fatalities and injuries from accidents (e.g., collision with a truck). Relating to onsite (within NTS) risk, the only potential hazard is on the 32 to 40 km (20 to 25 mi) of roadway that the safe secure trailer would travel. A group of flammable-liquid storage tanks located near the Mercury Facility is located about 30 m (100 ft) off the roadway and are protected by dikes. Based on accepted transportation accident rates, a transportation accident having serious consequences along this route would have a probability of less than or equal to 1 in 1 million.

¹ A closer onsite or nearby airfield could be used for DOE Transportation Safeguards System air cargo shipments only.
Note: TSS - Transportation Safeguards System. Source: DOE 1991j.

² Fatalities.
Source: RADTRAN model results.

³ Estimated fatalities per year.

⁴ Same as No Action risk.

⁵ Lowest potential impact of all site combinations.

⁶ Highest potential impact of all site combinations.
Source: RADTRAN model results.

⁷ Estimated fatalities per year. Specific risk for these different cases is presented in appendix table G.1-1.

⁸ Highest potential impact of all site combinations.

⁹ Lowest potential impact of all site combinations.
Source: RADTRAN model results.

¹⁰ Local acceleration due to gravity.

¹¹ Meters per second.

¹² Centimeters.

¹³ Kilotons. All peak values reported are the largest of the radial and transverse components.
Source: NT DOE 1996c.