The effect of ruminal and duodenal application of different levels of calcium and phosphorus to sheep on semi-purified diets

Nege behandelings van CaoPo, Car, Cad, Pd, (CAP)r, CadPr, (CaP)d en CarPd (o = geen supplementasie; r -= aan rumen en d = aan duodenum) is ondersoek. P-supplementasie onderdruk Ca-absorpsie en -retensie en omgekeerd. P-absorpsie in duodenum is konsentrasie-afhanklik en Ca- en anolgllniese P-konsentrasie in die rumen is afhanklik van die inname: Ca meer so as P. Serum-Ca was betreklik konstant terwyl serum anorganiese P (Pi) beduidend deur die behandelings beinvloed is. Ca- en P-onderhoudsbehoeftes kan as 3,0 en 1,8 g/dag en die totale endogene verlies 0,5 en ongeveer 0,34 g/dag onderskeidelik beskou word. Die Ca/p verhouding vir die rumen-mikro-organismes is nie kritiesnie maar die Ca-peil mag gewoonweg meer krities as die P-peil in die rumen wees. 'n'Wye Ca/P verhouding vir herkouers is aan te beveel. Konsentrasiesvan Pi en vetsure in rumenvloeistof is betekenisvol gekorreleerd sowel as rumen-Ca met vetsure en TCA-N.The effect of different levels and combinations of Ca and P consisting of nine treatments as CaoPo, Car, Pr,Cad, Pd, (CaP)r, CadPr, (CaP)d and CarPd were investigated with an unrestricted semi-purified diet (r = to the rumen; d = to the duodenum, and o = no supplementation). P supplementation, irrespective of site, depressed Ca absorption and retention and vice versa. P absorption is favoured by high concentrations in the duodenum, absorption thus being concentration dependent. Ca and inorganic P (Pi) concentration in rumen liquor isintake dependent; the former more so than the latter. The serum Ca was relatively stable despite treatment differences, whereas serum Pi concentrationwas significantly affected by treatments. Serum Ca and Pi are negatively correlated (r = -0,5307). Car resulted in the highest concentrationof serum Ca but depressed serum Pi more effectively than e.g. CaoPo and Cad. The Ca and P maintenance requirements were found to be 3,0 and 1,8 g/day and the endogenous loss 0,5 and approximately 0,34 g/day respectively. The Ca/P ratio for the rumen microorganisms is not critical but the rumen Ca level may usually be of a more critical nature in contrast to rumen Pi levels, and thus, favouring a wider ratio than is usually recommended for non-ruminants. Concentrations of rumen liquor Pi and VFA were found to be significantly associated as well as rumen Ca with VFA and TCA-N, respectively.

Recommendations for a restart of molten salt reactor development

Abstract The concept of the molten salt reactor (MSR) refuses to go away. The Generation-IV process lists the MSR as one of the six concepts to be considered for extending fuel resources. Good fuel utilization and good economics are required to meet the often-cited goal of 10 TWe globally and 1 TWe for the US by non-carbon energy sources in this century by nuclear fission. Strong incentives for the molten salt reactor design are its good fuel utilization, good economics, amazing fuel flexibility and promised large benefits. It can: use thorium or uranium; be designed with lots of graphite to have a fairly thermal neutron spectrum or without graphite moderator to have an epithermal neutron spectrum; fission uranium isotopes and plutonium isotopes; produces less long-lived wastes than today's reactors by a factor of 10-100; operate with non-weapon grade fissile fuel, or in suitable sites it can operate with enrichment between reactor-grade and weapon grade fissile fuel; be a breeder or near breeder; operate at temperature >1100°C if carbon composites are successfully developed. Enhancing 232 U content in the uranium to over 500 ppm makes the fuel undesirable for weapons, but it should not detract from its economic use in liquid fuel reactors: a big advantage in nonproliferation. Economics of the MSR are enhanced by operating at low pressure and high temperature and may even lead to the preferred route to hydrogen production. The cost of the electricity produced from low enriched fuel averaged over the life of the entire process, has been predicted to be about 10% lower than that from LWRs, and 20% lower for high-enriched fuel, with uncertainties of about 10%. The development cost has been estimated at about 1 B$(e.g., a 100 M$/year base program for 10 years) not including construction of a series of reactors leading up to the deployment of multiple commercial units at an assumed cost of 9 B$(450 M$/year over 20 years). A benefit of liquid fuel is that smaller power reactors can faithfully test features of larger reactors, thereby reducing the number of steps to commercial deployment. Assuming electricity is worth $50 per MWe h, then 50 years of 10 TWe power level would be worth 200 trillion dollars. If the MSR could be developed and proven for 10 B$ and would save 10% over its alternative, the total savings over 50 years would be 20 trillion dollars: a good return on investment even considering discounted future savings. The incentives for the molten salt reactor are so strong and its relevance to our energy policy and national security are so compelling that one asks, ''Why has the reactor not already been developed?"

Interaction of Laser Radiation with Plasmas and Nonadiabatic Motion of Particles in Magnetic Fields

Contains reports on two research projects.United States Atomic Energy Commission (Contract AT(30-1)-3285

Analyses in Support of Z-Pinch IFE and Actinide Transmutation - LLNL Progress Report for FY-06

This report documents results of LLNL's work in support of two studies being conducted by Sandia National Laboratories (SNL): the development of the Z-pinch driven inertial fusion energy (Z-IFE), and the use of Z-pinch driven inertial fusion as a neutron source to destroy actinides from fission reactor spent fuel. LLNL's efforts in FY06 included: (1) Development of a systems code for Z-IFE and use of the code to examine the operating parameter space in terms of design variables such as the Z-pinch driver energy, the chamber pulse repetition rate, the number of chambers making up the power plant, and the total net electric power of the plant. This is covered in Section 3 with full documentation of the model in Appendix A. (2) Continued development of innovative concepts for the design and operation of the recyclable transmission line (RTL) and chamber for Z-IFE. The work, which builds on our FY04 and FY05 contributions, emphasizes design features that are likely to lead to a more attractive power plant including: liquid jets to protect all structures from direct exposure to neutrons, rapid insertion of the RTL to maximize the potential chamber rep-rate, and use of cast flibe for the RTL to reduce recycling and remanufacturing costs and power needs. See Section 4 and Appendix B. (3) Description of potential figures of merit (FOMs) for actinide transmutation technologies and a discussion of how these FOMs apply and can be used in the ongoing evaluation of the Z-pinch actinide burner, referred to as the In-Zinerator. See Section 5. (4) A critique of, and suggested improvements to, the In-Zinerator chamber design in response to the SNL design team's request for feedback on its preliminary design. This is covered in Section 6

Interaction of Laser Radiation with Plasmas and Nonadiabatic Motion of Particles in Magnetic Fields

Contains reports on three research projects.United States Atomic Energy Commission (Contract AT(30-1)-3285

Axisymmetric Tandem Mirror Magnetic Fusion Energy Power Plant with Thick Liquid-Walls

A fusion power plant is described that utilizes a new version of the tandem mirror device including spinning liquid walls. The magnetic configuration is evaluated with an axisymmetric equilibrium code predicting an average beta of 60%. The geometry allows a flowing molten salt, (flibe-Li{sub 2}BeF{sub 4}), which protects the walls and structures from damage arising from neutrons and plasma particles. The free surface between the liquid and the burning plasma is heated by bremsstrahlung radiation, line radiation, and by neutrons. The temperature of the free surface of the liquid is calculated, and then the evaporation rate is estimated from vapor-pressure data. The allowed impurity concentration in the burning plasma is taken as 1% fluorine, which gives a 17% reduction in the fusion power owing to D/T fuel dilution, with F line-radiation causing minor power degradation. The end leakage power density of 0.6 MW/m{sup 2} is readily handled by liquid jets. The tritium breeding is adequate with natural lithium. A number of problem areas are identified that need further study to make the design more self-consistent and workable; however, the simple geometry and the use of liquid walls promise the cost of power competitive with that from fission and coal

Progress on the conceptual design of a mirror hybrid fusion--fission reactor

A conceptual design study was made of a fusion-fission reactor for the purpose of producing fissile material and electricity. The fusion component is a D-T plasma confined by a pair of magnetic mirror coils in a Yin-Yang configuration and is sustained by neutral beam injection. The neutrons from the fusion plasma drive the fission assembly which is composed of natural uranium carbide fuel rods clad with stainless steel and helium cooled. It was shown conceptually how the reactor might be built using essentially present-day technology and how the uranium-bearing blanket modules can be routinely changed to allow separation of the bred fissile fuel. (MOW