A significant portion of the cost of fabricating LMFBR fuels is in the non-fuel components such as fuel pin cladding, fuel assembly ducts and end fittings. The contribution of these to fuel fabrication costs, based on FFTF experience and extrapolated to large LMFBR fuel loadings, is discussed. The extrapolation considers the expected effects of LMFBR development programs in progress on non-fuel component costs.

Installation of the major hardware subsystems for MFTF is nearing completion. These subsystems include the Fusion Chamber System, the eighty KV Neutral Beam System, the Superconducting Magnet System, and the Personnel Safety System. The Local Controls group has undertaken a uniform aproach to implementing the control systems for all of these hardware subsystems. This approach has two major aspects: (1) to provide a stand-alone computer control system with a remote, portable terminal so that computer control can be provided at the site of the hardware for initial testing, (2) to provide hardware simulators so that the complicated MFTF computer control system can be tested independent of the hardware. The software and hardware tools which were developed to carry out this plan will be described. Our experiences with bringing up subsystems containing up to 900 separate channels of control and status will also be described.

The Supervisory Control and Diagnostic System (SCDS) for the Mirror Fusion Test Facility (MFTF) consists of nine 32-bit minicomputers arranged in a tightly coupled distributed computer system utilizing a share memory as the data exchange medium. Debugging of more than one program in the multi-processor environment is a difficult process. This paper describes what new tools were developed and how the testing of software is performed in the SCDS for the MFTF project.

Passive pumping of tandem-mirror thermal barriers by a combination of E x B and gradient magnetic field (grad-B) drifts has the advantages of engineering simplicity, low power consumption and selectivity in pumping out trapped thermal ions while retaining high-energy sloshing ions, hot electrons, and central-cell ions. Specifically, installing dc perturbation coils in suitable locations utilizes the differences in the turning points of these populations. In addition, we can dispose of the thermalized alphas and impurities after they diffuse into velocity space accessible to the grad-B pumping. Questions concerning adiabaticity are under investigation through guiding-center drift calculations.

A roll compaction and roll granulation system has been designed and fabricated to replace conventional preslugging and crushing operations typically used in the fabrication of mixed oxide nuclear fuel pellets. This equipment will be of maintenance advantage with only the compaction and granulation rolls inside containment. The prototype is being tested and the results will be reported within a year.

Plasma confinement in the Tandem Mirror Experiment (TMX) is described. Axially confining potentials are shown to exist throughout the central 20-cm core of TMX. Axial electron-confinement time is up to 100 times that of single-cell mirror machines. Radial transport of ions is smaller than axial transport near the axis. It has two parts at large radii: nonambipolar, in rough agreement with predictions from resonant-neoclassical transport theory, and ambipolar, observed near the plasma edge under certain conditions, accompanied by a low-frequency, m = 1 instability or strong turbulence.

The generalized conjugate gradient scheme based on the k-line block Jacobi splitting A = M-N was studied for solving model two-dimensional parabolic and elliptic difference equations AU = F tilde. A represents the matrix ch/sup ..cap alpha../-h/sup 2/..delta../sub h/. Eigenvalues of M/sup -1/N cluster, and the cluster radii decrease as ch/sup ..cap alpha../ or k increases. Computations with k = 4, 8, 16, 32, and ch/sup ..cap alpha../ = 0, h, 2 are discussed.

Magnetic switching offers an alternative to overcoming the rep-rate and life limitations of the spark gaps in the ETA/ATA induction accelerators. The principle has been applied for many years to radar modulators but at much lower power levels and longer pulse lengths. Comparatively recent developments in magnetic materials together with some optimal circuits have made it possible to go well beyond the state of the art. A magnetic modulator has been built which steps up and compresses a 25 kV, 5 ..mu..s pulse into a 250 kV, 50 ns pulse. A second magnetic modulator has been built and installed to replace four Blumleins and spark gaps in order to provide triggers for the complete ETA injector and accelerator. The paper outlines some practical and theoretical considerations affecting the design of the magnetic pulse generator.

The long term residual heat removal for the Clinch River Breeder Reactor Plant (CRBRP) is accomplished through the use of three protected air-cooled condensers (PACC's) each rated at 15M/sub t/ following a normal or emergency shutdown of the reactor. Steam is condensed by forcing air over the finned and coiled condenser tubes located above the steam drums. The steam flow is by natural convection. It is drawn to the PACC tube bundle for the steam drum by the lower pressure region in the tube bundle created from the condensing action. The concept of the tube bundle employs a unique patented configuration which has been commercially available through CONSECO Inc. of Medfore, Wisconsin. The concept provides semi-parallel flow that minimizes subcooling and reduces steam/condensate flow instabilities that have been observed on other similar heat transfer equipment such as moisture separator reheaters (MSRS). The improved flow stability will reduce temperature cycling and associated mechanical fatigue. The PACC is being designed to operate during and following the design basis earthquake, depressurization from the design basis tornado and is housed in protective building enclosure which is also designed to withstand the above mentioned events.

We describe the software structures that control the operation of MFTF Sustaining Neutral Beam Power Supplies (SNBPS). These components of the Supervisory Control and Diagnostics System (SCDS) comprise ten distinct tasks that exist in the SCDS system environment. The codes total about 16,000 lines of commented Pascal code and occupy 240 kbytes of memory. The controls have been running since March 1981, and at this writing are being integrated to the Local Control System and to the power supply Pulse Power Module Controller.

For inertial confinement fusion plasma diagnostics, x-ray diode (XRD) detectors using conventional cathodes are not sensitive enough to measure x-rays above approx. 1.5 keV. However, for laser driver fusion targets, x-rays in the range of 2 to 5 keV are important because of their mobility in the target. We have successfully used fluor-microchannel plate (MCP) detectors to obtain absolute x-ray measurements in the 2 to 5 keV range. Recent data obtained from experiments on the Shiva laser system are presented. In addition, designs for a variety of channels in the range using fluor-MCP and CsI-XRD's above 1.5 keV will be discussed.