A letter report issued by the Government Accountability Office with an abstract that begins "One key way that the Federal Aviation Administration (FAA) makes air travel safer is to inspect the manufacture, operation, and maintenance of aircraft that fly in the United States. To better direct its resources, FAA is shifting from an inspection process that relied on spot-checks of compliance with regulations to one that evaluates operating procedures and analyzes inspection data to identify areas that pose the most risk to safety (called system safety). While FAA believes the new approach requires some technical knowledge of aircraft, Congress and GAO have long-standing concerns over whether FAA inspectors have enough technical knowledge to effectively identify risks. GAO reviewed the extent that FAA follows effective management practices in ensuring that inspectors receive up-to-date technical training. In addition, GAO is reporting on technical training that the aviation industry provides to FAA."

A letter report issued by the Government Accountability Office with an abstract that begins "Following the invasion of Iraq in March 2003, concerns were raised about the security of Iraq's radiological sources. Such sources are used in medicine, industry, and research, but unsecured sources could pose risks of radiation exposure, and terrorists could use them to make "dirty bombs." This report provides information on (1) the readiness of the Department of Defense (DOD) to collect and secure sources, (2) the number of sources DOD collected and secured, (3) U.S. assistance to help regulate sources in Iraq, and (4) the lessons DOD and the Department of Energy learned."

A letter report issued by the Government Accountability Office with an abstract that begins "The Maritime Administration (MARAD) has more than 100 obsolete and deteriorating ships awaiting disposal that pose potentially costly environmental threats to the waterways near where they are stored. Congress, in 2000, mandated that MARAD dispose of them by September 30, 2006. While MARAD has various disposal options available, each option is complicated by legal, financial, and regulatory factors. In this report, GAO assesses (1) whether MARAD will meet the September 2006 disposal deadline for these ships and, if not, why not; (2) the extent that MARAD has used alternative disposal methods other than scrapping, and barriers to using other methods; (3) the appropriateness of MARAD's methods for procuring ship disposal services; and (4) the impact of foreign competition and other factors on reducing disposal costs."

A letter report issued by the Government Accountability Office with an abstract that begins "GAO is required to audit the consolidated financial statements of the U.S. government. Due to the significance of the federal debt held by the public to the governmentwide financial statements, GAO has also been auditing the Bureau of the Public Debt's (BPD) Schedules of Federal Debt annually. The audit of these schedules is done to determine whether, in all material respects, (1) the schedules are reliable and (2) BPD management maintained effective internal control relevant to the Schedule of Federal Debt. Further, we test compliance with selected provisions of significant laws related to the Schedule of Federal Debt. Federal debt managed by BPD consists of Treasury securities held by the public and by certain federal government accounts, referred to as intragovernmental debt holdings. The level of debt held by the public reflects how much of the nation's wealth has been absorbed by the federal government to finance prior federal spending in excess of federal revenues. Intragovernmental debt holdings represent balances of Treasury securities held by federal government accounts, primarily federal trust funds such as Social Security, that typically have an obligation to invest their excess annual …

A letter report issued by the Government Accountability Office with an abstract that begins "The International Atomic Energy Agency's (IAEA) safeguards system has been a cornerstone of U.S. efforts to prevent nuclear weapons proliferation since the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) was adopted in 1970. IAEA has strengthened its safeguards system and increased efforts to combat nuclear terrorism by helping countries secure nuclear and radioactive material and facilities. This report (1) identifies the steps IAEA has taken to strengthen safeguards, (2) assesses the challenges in implementing strengthened safeguards, (3) identifies U.S. financial support for safeguards, and (4) describes IAEA's efforts to help secure nuclear material and facilities."

A letter report issued by the Government Accountability Office with an abstract that begins "The Defense Logistics Agency's (DLA) mission is, in part, to provide food, fuel, medical supplies, clothing, spare parts for weapon systems, and construction materials to sustain military operations and combat readiness. To protect the information and information systems that support its mission, it is critical that DLA implement an effective information security program. GAO was asked to review the efficiency and effectiveness of DLA's operations, including its information security program. In response, GAO determined whether the agency had implemented an effective information security program."

A letter report issued by the Government Accountability Office with an abstract that begins "After security conditions in Iraq began to deteriorate in June 2003, the U.S.-led Coalition Provisional Authority (CPA) included restoring essential services in Iraq, such as water and sanitation, as part of its strategy for establishing a secure, peaceful, and democratic Iraq. From 1991 to 2003, a decreasing number of Iraqis had access to safe drinking water and sanitation services, and water-borne disease rates rose. The United States has made available $2.6 billion for rebuilding the water and sanitation sector. As part of GAO's review of Iraq reconstruction under the Comptroller General's authority, we assessed U.S. activities in the water and sanitation sector, including (1) the funding and status of U.S. activities, (2) U.S. efforts to measure progress, (3) the factors affecting the implementation of reconstruction activities, and (4) the sustainability of U.S.-funded projects."

A letter report issued by the Government Accountability Office with an abstract that begins "The Department of Homeland Security's (DHS) Atlas program is intended to modernize Immigration and Customs Enforcement's (ICE) information technology (IT) infrastructure. By congressional mandate, DHS is to develop and submit for approval an expenditure plan for Atlas that satisfies certain legislative conditions, including a review by GAO. GAO was asked to determine whether the plan satisfied certain legislative conditions and to provide observations on the plan and management of the program."

A letter report issued by the Government Accountability Office with an abstract that begins "Recipients of federal government contracts for services are subject to wage, hour, benefits, and safety and health standards under the McNamara-O'Hara Service Contract Act (SCA) of 1965, as amended, which specifies wage rates and other labor standards for employees of contractors. SCA requires the Department of Labor (DOL) to set locally prevailing wage rates and other labor standards for employees of contractors furnishing services to the federal government. DOL's Employment Standards Administration's Wage and Hour Division (WHD) administers the SCA and each year determines prevailing wage and fringe benefit rates for over 300 standard service occupations in 205 metropolitan areas. SCA also authorizes DOL to enforce contractor compliance with SCA provisions. This report describes how DOL (1) establishes locally prevailing wages and fringe benefits and (2) enforces SCA."

The high level waste storage double-shell tanks at the Hanford site are highly basic. The high basicity is a key factor in controlling the chemical behavior of different components of the waste and in influencing the corrosion rate of the carbon steel primary tanks. However, the introduction of atmospheric CO2 can act to reduce the pH of the tank wastes over time and possibly alter the corrosion rate of the carbon steel tanks. In order to at least partially address this issue for waste tank 241-AN-107, thermodynamic modeling calculations were performed to predict the changes in pH and carbonate concentration that could occur as CO2 is absorbed from the atmosphere. The calculations extended to complete equilibrium with the partial pressure of CO2 in the atmosphere (i.e. pCO2 = 10-3.5 atm). Simulations were performed for both the “upper” segments of tank 241-AN-107, which have been influenced by the introduction of high concentrations of NaOH to the supernatant, and for the “lower” segments where the salt cake/interstitial liquid have not been substantially altered by the introduction of base concentration.

Tritium contaminated concrete rubble from the 232-F Tritium Facility was disposed in the Slit 1 Trenches 1 and 2 in 1997. A Special Analysis (SA) has been performed to evaluate any impact this disposal may have on the groundwater. The SA assumed that the disposed concrete rubble was fully saturated at the time of disposal, however if the concrete was less than fully saturated, migration of tritium out of the concrete would be slower than under fully saturated conditions. Therefore if the concrete at disposal was less than fully saturated, the PA assumption of full saturation would be a conservative assumption. In order to evaluate whether the PA assumption resulted in a conservative analysis from the standpoint of the concrete saturation, concrete rubble samples were collected from various facilities being demolished at the Savannah River Site (SRS) and evaluated for in-field moisture content, absorbable moisture, and water exchangeable porosity. The purpose of this task was to collect concrete rubble samples from various demolished SRS facilities for the purpose of determining in-field moisture content, absorbable moisture, and water exchangeable porosity. Since moisture content testing for concrete rubble is not typical, existing ASTM Standards were reviewed for method and procedure development.

In a conventional permanent magnet (PM) machine, the air-gap flux produced by the PM is fixed. It is difficult to enhance the air-gap flux density due to limitations of the PM in a series-magnetic circuit. However, the air-gap flux density can be weakened by using power electronic field weakening to the limit of demagnetization of the PMs. This paper presents the test results of controlling the PM air-gap flux density through the use of a stationary brushless excitation coil in a reluctance interior permanent magnet with brushless field excitation (RIPM-BFE) motor. Through the use of this technology the air-gap flux density can be either enhanced or weakened. There is no concern with demagnetizing the PMs during field weakening. The leakage flux of the excitation coil through the PMs is blocked. The prototype motor built on this principle confirms the concept of flux enhancement and weakening through the use of excitation coils.

The intended purpose of the multiscale thermohydrologic model (MSTHM) is to predict the possible range of thermal-hydrologic conditions, resulting from uncertainty and variability, in the repository emplacement drifts, including the invert, and in the adjoining host rock for the repository at Yucca Mountain. The goal of the MSTHM is to predict a reasonable range of possible thermal-hydrologic conditions within the emplacement drift. To be reasonable, this range includes the influence of waste-package-to-waste-package heat output variability relevant to the license application design, as well as the influence of uncertainty and variability in the geologic and hydrologic conditions relevant to predicting the thermal-hydrologic response in emplacement drifts. This goal is quite different from the goal of a model to predict a single expected thermal-hydrologic response. As a result, the development and validation of the MSTHM and the associated analyses using this model are focused on the goal of predicting a reasonable range of thermal-hydrologic conditions resulting from parametric uncertainty and waste-package-to-waste-package heat-output variability. Thermal-hydrologic conditions within emplacement drifts depend primarily on thermal-hydrologic conditions in the host rock at the drift wall and on the temperature difference between the drift wall and the drip-shield and waste-package surfaces. Thus, the ability to predict a …

Using spin-polarized relativistic density functional theory the electronic and magnetic structures for the plutonium compounds Pu{sub 3}M(M = Al; Ga; In) and PuNp have been investigated. For the first group of compounds the enhanced hybridization between Pu 5f and p-states of alloying element, as it has been found in spin-polarized calculations, is believed to be the main reason for the higher formation energies obtained in such kind of studies in comparison with the non-spin-polarized case. Also, comparative analysis of the actinides U, Np, Pu, Am, and Cm has been performed based on their electronic and magnetic structure. Some noticeable difference in the calculated magnetic structure was discovered between the actinide with local magnetic moments (Cm) and the actinides (Pu, Am) in which magnetic moments were found only in the calculations.

This cleanup verification package documents completion of remedial action for the 300-8 waste site. This waste site was formerly used to stage scrap metal from the 300 Area in support of a program to recycle aluminum.

Ben Cap, LLC, has a technology that utilizes bebtonite to plug wells. The bentonite is encapsulated in a cardboard capsule, droped down to the bottom of the well where it is allowed to hydrate, causing the bentonite to expand and plug the well. This method of plugging a well is accepted in some, but not all states. This technology can save a significant amount of money when compared to cementing methods currently used to plug and abandon wells. The test objective was to obtain the terminal velocity of the capsule delivery system as it drops through a column of water in a wellbore. Once the terminal velocity is known, the bentonite swelling action can be timed not to begin swelling until it reaches the bottom of the well bore. The results of the test showed that an average speed of 8.93 plus or minus 0.12 ft/sec was achieved by the capsule as it was falling through a column of water. Plotting the data revealed a very linear function with the capsules achieving terminal velocity shortly after being released. The interference of the capsule impacting the casing was not readily apparent in any of the runs, but a siginal sampling anomaly …

The objective of this project is to design, fabricate and demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind Department of Energy study at the Rocky Mountain Oilfield Testing Center. The performance of the scanner was inconsistent during the blind study. However, most of the leaks were outside the view of the multi-spectral scanner that was developed during the first year of the project. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. A prototype scanner was built and evaluated during the second year of the project. Only laboratory evaluations were completed during the second year. The laboratory evaluations show the feasibility of using …

The relativistic spin-polarized density functional theory has been used for the study of electronic and magnetic structure of the compounds NpM{sub 2}, PuM{sub 2} and AmM{sub 2} (M = Mn; Fe;Co;Ni). It has been shown that the peculiarities in their magnetic properties come mainly from the hybridization between 5f-electrons of actinides and 3d-electrons of transition metals. It is interesting, that existence of the local magnetic moments appears to be possible on the atoms, despite the fact that Hill's condition is not satisfied for these compounds of actinides. Besides, the electronic and magnetic structures of PuU have been studied and the comparative analysis of them with another compounds of plutonium and its neighbors in Periodic System: PuNp and PuAm has been performed. It has been found that in all the cases the electronic structure formation is a result of a superposition of spin-orbit and exchange band splitting with some increasing of the role of exchange as we are going to americium. Atoms of plutonium appear to be near the point of equal importance of both interactions.

Spin-polarized relativistic density functional theory has been employed for the study of the electronic and magnetic structures for the compounds Np{sub 3}M and Am{sub 3}M (M = Al; Ga; In) and their comparison with plutonium's alloys Pu{sub 3}M has been made. It has been found that of the three actinides (Np, Pu, Am) only plutonium has its FCC structure essentially more stable after alloying with aforementioned elements. Apart from that, the electronic and magnetic structures for the system Pu-Am presented by three different compounds: Pu{sub 3}Am, PuAm, and PuAm{sub 3} have been investigated. Their magnetic structures have been found to be too robust in comparison with the experimental fact that magnetism in Pu-Am system depends strongly on the percentage of the americium in the alloy. One possible explanation consists in the overestimation of the spin splitting and in the disregarding of orbital dependence of the exchange-correlation potential.

This report examines the distribution of income in the United States, including factors that may help explain it, how it has changed over time, and how it compares with those of other countries.

Several theoretical studies have indicated that the presence of subsurface cavities in the vadose zone results in complete or partial diversion of flow around cavities. As a result, the region immediately below the cavities is partially shielded from the downward flux. This shadowing effect of cavities can be exploited in the design of dry subsurface storage facilities as an additional barrier to contain waste within or around the cavities. However, empirical evidence that supports these theories is lacking. This study is motivated by the inherent difficulty to make direct observation of the shadow zone as it occurs under very dry conditions. To aid future field and laboratory scale investigations of the shadow zone, we performed rigorous theoretical scrutiny of the conditions that result in the shadowing effect. We formulated relative permeability and saturation based criteria to identify the boundaries of the shadow zone. Analytical and numerical tools were used to develop dimensionless scaling laws that define the size of the shadow zone. Moreover, we analyzed the effect of natural perturbations (heterogeneity and fracturing) on the integrity of the shadow zone. The results will be used in selecting study sites; identifying observation locations and methods; and designing active tests to test …

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This report provides information on the amount of time taken to act on all Supreme Court nominations occurring between 1900 and the present. It focuses on the actual amounts of time that Presidents and the Senate have taken to act (as opposed to the elapsed time between official points in the process).

Estimating unknown system configurations/parameters by combining system knowledge gained from a computer simulation model on one hand and from observed data on the other hand is challenging. An example of such inverse problem is detecting and localizing potential flaws or changes in a structure by using a finite-element model and measured vibration/displacement data. We propose a probabilistic approach based on Bayesian methodology. This approach does not only yield a single best-guess solution, but a posterior probability distribution over the parameter space. In addition, the Bayesian approach provides a natural framework to accommodate prior knowledge. A Markov chain Monte Carlo (MCMC) procedure is proposed to generate samples from the posterior distribution (an ensemble of likely system configurations given the data). The MCMC procedure proposed explores the parameter space at different resolutions (scales), resulting in a more robust and efficient procedure. The large-scale exploration steps are carried out using coarser-resolution finite-element models, yielding a considerable decrease in computational time, which can be a crucial for large finite-element models. An application is given using synthetic displacement data from a simple cantilever beam with MCMC exploration carried out at three different resolutions.