In the last two or three years there has been a notable improvement in the knowledge and understanding of reactor lattice physics. During this interval, measurements of parameters have been improved and the methods of analysis have been greatly strengthened. It has become apparent that the classical ways for computing the lattice parameters are not sufficient. It is the purpose of this report to publish under one cover as much of the most recent information as possible.

Nuclear safety specifications for storage, banding, or transfer of enriched uranium slugs depend upon slug arrangement and geometry, the presence of a moderator such as water or wood, and the presence of other fissionable materials and reflectors. Specifications are given for enriched I and E uranium slugs, solid uranium slugs of two types, and aluminum-uranium alloy slugs.

This report summarizes the operational experience and the data obtained on the 2AW Purex type process stream. The performance of an in-line alpha monitor for continuously monitoring Plutonium in Purex Process waste streams is described. The instrument has a lower limit of measurement of 1 x 10⁻⁶ grams of Plutonium per liter and can measure concentrations as high as 7.9 x 10⁻² grams/liter.

Pressure drops are reported for forced circulation flow of steam-water mixtures in a 23.5 foot long, 1.43 inch ID, 0.1 inch thick, horizontal annulus. The inner surface of the annulus was uniformly heated over a range from 97,000 to 233,000 Btu/hr-ft², exit pressures extended from 100 to 500 psig, and exit steam qualities varied from 0 to 60% by weight. Liquid water entered the annulus and boiling lengths up to 15 feet were investigated. Moreover, the Woods and the Martinelli and Nelson methods of calculating two-phase pressure drop were applied to the experimental conditions, and the deviations between the analytical and the test results are presented.

A nuclear safety indicator has been described. This is an instrument which will make it possible to determine the safety of performing contact maintenance work on certain long columns used in the continuous flow processing of plutonium.

Weld rejects have accounted for a large percent of the total rejects in the production of fuel elements, and consequently, the investigation of the causes of these rejects was a desirable undertaking. Although previous investigations had made possible a satisfactory standardization of the welding process, it was felt of value to more sharply define the causes of weld rejects and to facilitate the control of these causes.

The PRTR pressure loop is an experimental facility to be installed in the Plutonium Recycle Test Reactor, Building 309, for use in testing the feasibility of reactor cooling systems utilizing high pressure water or steam as the coolant. It will furnish operating experience with such systems and serve to test fuel elements and components designed to operate in such environments.

The region in which Hanford's chemical processing plant areas (separation areas) are located in the central portion of the Hanford Works area on a plateau, shaped like a giant bar, of glaciofluviatile materials. The general locations of these areas is shown in Figure 1. The region studied rises from 200 to 300 feet above the surrounding area and encompasses approximately 40 square miles or somewhat less than 8% of the Hanford reservation (Figure 2). Within the region are located the chemical separation plants and most of the major waste disposal sites.

The calculation of shielding the thickness for plutonium is complicated by the many different energies represented in the gamma radiation emitted during decay of the plutonium isotopes. Dose rate predictions are also frequently confused by gamma from varying content of fission product impurities in the plutonium, as well as other gamma radiation induced through alpha and neutron particle absorption within the source material or its environment. After assumptions are made for these many factors the radiation data for shielding determination is still frequently inadequate because of wide variations in dose rates resulting from self-absorption. The degree if self-shielding is in turn dependent on nature of the plutonium compound, degree of compactness, weight, and over-all geometrical distribution of the source material. By preparing a variety of plutonium samples representing combinations of these varying factors, actual dose rates and gamma spectra, as obtained from them, can then be extrapolated for application to specific situations.

The processing of irradiated fuels from power and propulsion reactors is planned by Hanford Atomic Products Operation as part of the Atomic Energy Commission's interim reprocessing scheme. The several chemical processes proposed for the reprocessing of these fuels may be divided into two categories: first, total dissolution processes which dissolve both fuel element cladding and core material and, second, selective dissolution processes which dissolve either cladding or core material. The Niflex process uses a nitric and hydrofluoric acid solution for the total dissolution of stainless steel clad uranium fuel elements.

This paper discusses a remotely operated system developed to transport (raise and lower) a 1/2 gram radium gamma radiation source for calibration of the HAPO film badges and finger rings. The system employs the rotometer principle for positioning the source for operating purposes. An accurate timer is utilized to assure the desired exposure time.

Property changes to common graphites resulting from reactor irradiation depends strongly on the temperature of exposure. Radiation affects at 30 C and 400 to 500 C are quite well known; however, at intermediate temperatures, results are not well known although a large volume of graphite in most reactors operate in this range. Production test, IP-22A, was reactivated, after a dormant period of many months, to study radiation damage between 30 and 400 C. This report concerns mainly the experimental details and evaluation of the equipment necessary for the controlled temperature irradiation.

Basic Studies. It has been reported previously that a reduction of PuO2 to a suboxide does not occur when a powder sample is heated for one hour at 1450 C. To investigate this anomaly, the present hooded facilities were converted from full air flow to an argon atmosphere to prevent oxidation of a possible suboxide. Five grams of PuO2 powder were heated in dry hydrogen to 1500 C for times of one and eight hours. Immediately after discharge, they were mounted and transferred to a helium atmosphere diffractometer hood. The resulting x-ray diffraction pattern consisted only of the single FCC PuO2 phase.

On a project of the magnitude and complexity of the Plutonium Recycle Test Reactor is was considered prudent engineering practice to obtain an independant design review by a competent off-site group that had not participated in any way in the development of the design. Accordingly, the Atomic Power Equipment Department of the General Electric Company was requested to make such an engineering review, and an Assistance to Hanford contract authorizing this work was approved by the Atomic Energy Commission in November, 1958.

The Atomic Energy Commission has assigned Hanford Atomic Products Operation the responsibility of reprocessing some of the slightly enriched uranium fuel elements from nuclear power reactors. Some stainless steel clad fuel elements contain sodium or a sodium-potassium alloy as a heat transfer medium between metallic core and outer sheath. The nature of the reaction between water and sodium is well known; however, the reaction between sodium and an oxidizing acid is more energetic and not so well known. The unknown factor of interest is the pressure generated by the reaction between the next transfer medium and the acid used for fuel dissolution prior to solvent extraction. The scouting studies discussed in this report were made to determine hydraulic pressures developed when sodium is exposed to cold concentrated nitric acid beneath the liquid surface.

The NPR design calls for carbon steel to be the major constituent in the reactor coolant piping system. The piping and its associated fittings will, in all likelihood, be exposed to atmospheric weather conditions during the period of reactor construction. This type of exposure causes rusting. From experience gained during the startup of KER Loop 1 it is expected that there will be initially high NPR coolant activity levels. The high activity during the startup of KER Loop 1 was partially caused by the activation of rust that was eroded from pipe walls. Prevention of rusting on the carbon steel prior to its introduction into the coolant system would reduce the initial activity levels.

This document presents a set of machine-computed curves involving a wide range of Kb and Kc, from which both thermal and resonance values of (E-1) may be obtained.

The information in this report is based on experience with a similar unit installed on experimental pule columns in the 321 Building. These installations were made to demonstrate the feasibility of the system. In one case, the installation on the 2A Prototype Column, the differential pressure cell (D/P cell) bottom interface control system was monitored by a capacitance-type instrument. The other installations were made on glass columns and were monitored visually.

In the Columbia River downstream from Richland, Washington there is a gradual decrease in concentration of radioactive isotope. At any one location there are fluctuations due to factors such as dilution and decay time. During this period at all locations the concentration of alpha particle emitters in water averaged below the detection limit. Beta particle emitters in water upstream of McNary Dam decreased slightly due to increased river flow this quarter, with averages at various locations. Downstream from McNary Dam, beta particle emitter average concentrations in water were about the same as the past three quarters.

During this quarter, the Hanford Atomic Products Operation reorganized with the elimination of the Radiological Sciences Department as a separate organizational entity. The new structure which was effective on September 1, 1956, is outlined in this report to indicate the new relationships.

Transfer operations of highly radioactive solutions by the normal transfer pipette leads in most instances to a spread of contamination in the shielded facility. In the dripless pipette, the solution is held in the reservoir by the use of the siphon principle.

In the fall of 1952, a pilot plant batch dissolution study was carried out to obtain the data required for the design of the Purex Plant dissolvers. Particular emphasis was placed on the rate of dissolution and the efficiency of nitrogen oxide recovery from the dissolver off-gas. The results are presented in this report.