In the Communications of the ACM of April, 1960, p. 240, there appeared two Algol algorithms for the computation of In, the modified Bessel function of the first kind. One of these algorithms uses a convergent series and the other an asymptotic series. Their author, Dorothea S. Clarke, did not give any information with regard to which algorithm is more appropriate in a given situation (a given situation meaning the computation of In (x) for a definite pair of numbers n and x). Such information is necessary, however, if the algorithms are to be useful, particularly since the asymptotic series is in many cases not valid.

On 3/14/60 the Applied Physics Corporation was awarded a subcontract for the design and development of a high-temperature high-pressure spectrophotometer system based on the Cary Model 14pm Spectrophotometer insofar as possible, and consistent with our specifications, No. CTD-2, December 16, 1959.

Abstract: A zero power experiment on the SM-1 Core II included an element by element reactivity check of fuel elements and control rod absorber sections, and an estimate of burnable nuclear poison loading in stationary fuel elements. An approach to criticality was made by the inverse multiplication method, and critical rod bank position obtained as a function fuel loading up to full core loading. Minimum and maximum core reactivity measurements were obtained by selective loading of stationary fuel elements, and total excess K of the core was established. Power distribution measurements were taken in the regions of the core-reflector interface and the fuel-absorber interface in the control rod assemblies. The effectiveness of europium flux suppressors in the top of control rod fuel elements was determined, and power peaking was measured in stationary elements adjacent to control rod assembly water gaps. Survey measurements established the work of spiking clean, cold SM-1 cores with SM-2 elements and the work of water holes in the SM-1 Core. The reduced scope zero power experiment performed on SM-1A core I included an element by element uniformity check of stationary fuel elements, a core assembly test, comparison of Eu2O3 and B4C absorber sections, and development of …

Abstract: "Discussion is directed toward eventual optimization of the largest diffusion-pump systems. Less than 100 diffusion pump fluid molecules per cm 2/sec are possible to detect using an accumulation method. Optimization discussed demands highest possible system speed compatible with the above contamination rate. Bakeable oil diffusion pump systems, with equal orifice valve-tap units, without conventional baffling, permit theoretical through-put speeds up to 0.3 of the system orifice. The average backstreaming rate of oil in two unconventionally baffled commercial pumps of 6-in. and 10-in. size is reduced to < 3 x 10-(-4) g/cm-2/24 hr, including heating and cooling the pump boiler. A Ho factor of >0.4 is maintained. Results on trapping with activated alumina, retained by a wire mesh, at both liquid-nitrogen and room temperature are included. A variety of pumping speed measurements and bakeable combination valve-trap units are discussed."

Report discussing the "equilibrium uranium distribution between an aqueous nitric acid solution and a 30 per cent by volume solution of tributyl phosphate in a hydrocarbon diluent" (p. 2). This includes the necessary equations.

The following document describes the usage of the LRL 9-ZOOM code, a neutron diffusion theory reactor code for the IBM 709. The code has been modified to solve configuration of a series of stacked cylindrical disks, designating a new geometry case.

Applications of sheathed (metal) thermocouples may require in many instances, the insertion of the thermocouple thermal junction into an area that must be hermetically sealed to the outside. This same area usually contains highly reactive heat transfer medium such as an eutectic alloy of sodium and potassium of sodium alone. When fissionable materials are being irradiated, fission products that are driven off would also be present and must be contained under varying temperatures and pressures.

The Plutonium Recycle Test Reactor is heavy water moderated with a heavy or light water reflector contained by a complex aluminum vessel called a Calandria. ( See Figure 1). Construction of this vessel started in August, 1958, at a large West Coast vendor's plant and was completed at Hanford in December, 1959. The fabrication problems associated with a high integrity welded aluminum vessel were generally unrealized prior to this period. This report covers the fabrication of the Calandria and lists recommendations for improving the design and reducing the cost.

This semiannual progress report and future reports will be published as two documents to permit a wider distribution of the unclassified material. The report numbers are assigned in sequence so that the two reports will fall together when filed by report number.

Abstract. The cross section of photoneutron production in Be9 at energies of 1.692, 1.720, and 1.78 Mev has been investigated using radioisotope gamma-ray sources. Neutron counting was by manganous sulfate bathe and a long counter. Gamma-ray counting was by a scintillation spectrometer consisting of a NaI(T1) scintillation crystal and a 256 channel pulse-height analyzer. A theoretical treatment of the P [right arrow] S transition near threshold using square-well potentials is also presented.

Critical mass experiments to be conducted at HAPO will require dilute and concentrated plutonium solutions. Since very high plutonium concentrations (~2,000 g/l) cannot be attained in pumpable solutions, solid plutonium compounds will be utilized for this phase of the work. Mixtures of plutonium oxide and polyethylene, methyl methacrylate or paraffin compacted in containers have been considers for use in highly-concentrated plutonium systems of known hydrogen to plutonium atomic ratio (H/Pu).

Operating plant experiences in restoring to useful service failed equipment contaminated through exposures to radioactive processes is of international interest to the nuclear industry. In accordance with a request from the Hanford Operations Office of the United States Atomic Energy Commission this report of the various measures taken in rehabilitating for re-use expensive engineered equipment has been compiled by the General Electric Company. This report is a review and summary of the disposition of contaminated major processing equipment at Hanford Atomic Products Operation during 1958-1959 and a listing of 1) equipment buried, 2) equipment stored, to be buried or decontaminated, and 3) equipment decontaminated and returned to service.

This document will be concerned with the design, operation and maintenance of an automatic fuel element stamping machine. In order to take advantage of automatic unloading and length checking at the Acme-Gridley lathes in the 313 Building, automatic stamping of fuel elements is desirable. This, along with the need for a permanent canning line identification, resulted in a request for a machine to automatically stamp HAPO fuel elements on a production basis.

Organic compounds with high boiling points and low corrosion qualities have been considered for use as reactor coolants and moderators. Those being considered, however, have a greater tendency to leak than does water. A program to evaluate mechanical closures to be used for a leak-tight system for organic fluids has been established. Report HW-59446 covered descriptions of the facility used in this study and the primary results of tests covering two liquids, fittings, and instrumentation. This report will cover final results and other pertinent information.

The decontamination of the present Hanford reactors involves a once-through cleaning operation. Considerable interest has also been shown in determining the feasibility of this once-through technique for cleanup of certain portions of the NPR system. This report contains information on a series of tests performed in the 242-B single pass flow facility. Information concerning the following are presented: (1) Efficiency of decontaminating KER Loop 1 and 2 contaminated specimens. (2) Efficiency of decontaminating present reactor pigtails by different methods. (3) Areas that need further study.

Formulas derived from earlier work satisfactorily predicted low frequency ground effects resulting from the Pre-Gnome explosions, but they not predict high accelerations associated with high frequency ground waves. The Pre-Gnome experiments taken since indicated that accelerations and ground amplitudes are proportional to the explosive charge, but physical conditions limit extrapolation on this basis to relatively low yields. Predicted accelerations resulting from the 10 kt Gnome explosion in potash mines eight or more miles away will be somewhat less than from routine blasts in the mines. The compressional wave speed in the salt stratum of the area is about 14,000 feet per second.