Considerations of importance to decisions on an alternate nuclear program

The nuclear power program of the United States is based on the concept that nuclear plants of the thermal converter type—primarily those cooled and moderated by light water—will fill the generating needs in the early years, and that the fast breeder will be developed on a sufficiently rapid schedule to take over the major portion of the electrical load before our reserves of moderate-cost uranium are used up. In this plan the thermal converter reactors play an important, if not altogether essential, role as producers of plutonium for the initial inventory of the breeders. To reassess this plan, in the absence of any reliable model for the long-term U.S. economy in its relationship to energy supplies and costs, we are forced to use as input some estimate of the energy demand over a period of approximately a century. This input has a profound impact on the assessment, affecting not only our estimate of the urgency of development of the breeder, but conclusions as to optimum choice of converter reactors as well. Inasmuch as the demand is not an independent variable, but will surely depend upon the cost of power, this approach has obvious deficiencies.Since, however, the objective of planning is to make things happen as one wants them to—and what we are doing here is planning—I believe we should concentrate on making available the desirable quantities of electrical energy, rather than some smaller amounts which may indeed fill the demand if our plans go awry and the power cost rises drastically.I have therefore chosen a relatively generous demand projection, which amounts to 18.3 × 10⁷ MW-yr of total electrical energy over the next century, of which it is assumed that 70% will be generated by nuclear fission. In view of the great uncertainty of projection, a simple linear growth has been assumed.When one assesses the options for the future in terms of large energy productions, it is necessary to consider separately the case in which no fast breeder is assumed to be developed and the case in which it is assumed that the fast breeder is developed to a viable commercial stage, but possibly on a delayed schedule. In the former case the important performance characteristic of the nuclear plant is the amount of energy produced per unit of natural uranium fed into the system. In the latter case one must consider the production of plutonium for the fast breeder inventory. The important characteristic then becomes the amount of net plutonium produced per unit of natural uranium fed to the system. If the growth rate of breeder capacity is limited by plutonium availability, the efficiency of use of feed uranium, in terms of energy production, has little effect on the total quantity of natural uranium required.The minimum mission for fission power plants is assumed to be the supply of 70% of the total electrical demand over the next century, a period which might be a reasonable one for the development and large scale production of some alternate energy producer. If the light water nuclear plants produced all of this energy (13 × 10⁷ MW-yr) they would require some 25 million tons of natural U₃O₈: more than our estimated resources, even including those in the cost range of $100/lb. It is concluded that, in the absence of the fast breeder, an acceptable alternative would be a reactor whose power cost sensitivity to the price of natural U₃O₈ would be less than that of the light water reactor, by something like a factor of four.If we seek, not to replace the breeder in our plan, but to find some better converter than the LWR in the interim before its large-scale production, the considerations become more complex. For minimum long-term resource requirement we must provide first for plutonium production, up to the point that plutonium availability is never a limit to breeder growth. Up to that point, the building of plants which use up natural uranium without producing net plutonium can only increase the long-term consumption of uranium, regardless of how efficient they are in producing energy. I refer you to Fig. 3 for an illustrative set of curves which show typical characteristics of a converter-breeder system in which the early growth of breeder capacity is plutonium-limited.The optimum converter mix then depends on a number of considerations which we are unlikely to predict with any accuracy: the electrical demand curve, the development schedule of the breeder, the limitations other than plutonium availability to the rate of construction of breeders, and the breeding and inventory characteristics of the breeder. From the point of view of resource conservation alone, however, we cannot go wrong with an improved converter which can be made either an efficient energy producer or an efficient producer of plutonium, simply by changing its fuel cycle. This of course suggests the heavy water reactor.From the more practical point of view we must recognize that any decision to introduce a new converter type in the United States could slow down the development of the fast breeder, not only by diverting development and production resources, but also by appearing to reduce the urgency of that development. In the long run this might overbalance any direct benefit from the alternate converter type. I believe the one thing that can be shown by analysis is that the most effective way of conserving nuclear resources is to develop, introduce, and build the fast breeder as rapidly as possible. My own opinion is that the real incentive for looking at alternates is to provide some kind of a backup against the possibility, which I hope is a very remote one, that the fast breeder development may be stopped or severely delayed for non-technical reasons.     

Stimulation of phospholipase C-beta 2 by recombinant guanine-nucleotide-binding protein beta gamma dimers produced in a baculovirus/insect cell expression system. Requirement of gamma-subunit isoprenylation for stimulation of phospholipase C

Recombinant wild-type beta 1 gamma 1 dimers of signal-transducing guanine nucleotide-binding proteins (G proteins) and beta 1 gamma 1 dimers carrying a mutation known to block gamma-subunit isoprenylation (beta 1 gamma 1 C71S) were expressed in baculovirus-infected insect cells. Both wild-type and mutant beta 1 gamma 1 dimers were found in soluble fractions of infected cells upon subcellular fractionation. Anion exchange chromatographic and metabolic-radiolabeling studies revealed that the soluble beta 1 gamma 1 preparation contained approximately equal amounts of non-isoprenylated and isoprenylated beta 1 gamma 1 dimers. Soluble wild-type and mutant beta 1 gamma 1 dimers and native beta 1 gamma 1 dimers purified from bovine retina were reconstituted with recombinant phospholipase C-beta 2. Only isoprenylated beta 1 gamma 1 dimers were capable of stimulating phospholipase C-beta 2. The results show that gamma-subunit isoprenylation and/or additional post-translational processing of the protein are required for beta gamma subunit stimulation of phospholipase C.     

Proximity printing of chrome masks

We have investigated the application of proximity printing to the copying of chrome masks used for integrated circuit fabrication. The mask blanks were coated with various positive and negative photoresists. When plotting the difference in width between etched lines on the print and the corresponding feature on the mask as a function of the separation, one observes fluctuations due to the movement of the diffraction peaks in the optical image. For the negative resist, the averaged difference in width is approximately constant to separations of 25 micrometer (μm), while for positive resists it changes monotonically with increasing gap spacing. The measured results are compared with calculations using a model of the resist exposure and development and good agreement is obtained. On the basis of these results we conclude that proximity printing would be difficult to apply to mask replication, but that it has considerable promise for replicating 10X step-and-repeat reticles.     

Elektronenmikroskopische Beiträge zum Feinbau des buchenholzes (Fagus sylvatica L.)—Erste Mitteilung: Untersuchungen an Markstrahl-Parenchymzellen

Ohne Zusammenfassung

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Electron-microscopic contributions to the fine structure of beechwood (Fagus sylvatica L.)—Part I: investigations on ray parenchyma cells

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Mitteilung aus dem Institut für Holzforschung und Holztechnik der Universit?t München

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Herrn Dr. Eberhard Schmidt bin ich für die Anregung zu dieser Arbeit und fruchtbare Diskussionen sehr verbunden. Fr?ulein E. Baldermann danke ich für die sorgf?ltige Ausführung der elektronenmikroskopischen Pr?parationen.     

Verfahren zur Kristallisation aus Lösungen

Crystallization from solution . In general the processes occurring in crystallizers have previously been treated in only summary and phenomenological manner because only little was known about the joint action of the individual steps. An attempt has therefore been made, in the present survey, to examine the relationship between the physico-chemical properties of the relevant system, the process chosen, and engineering economics.     

Die einzelnen Lebensmittel (Chemie, Technologie, Analytik)

Ohne Zusammenfassung     

Backyard range-a real backyard (actually front yard, garage anddriveway) antenna range on a shoestring

The evolution of a range for developing and measuring antennas in the author's home, which is the location of his consulting company, is discussed. The range hardware is described. Examples of the pattern produced by the system are presented