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This report describes research, development, support, and test activities in the Sandia Laboratory Aerospace Nuclear Safety Program for May 1968.

The purpose of this program is to conduct studies in the freshwater environment to acquire data needed to evaluate and predict the potential radiation hazards to human populations in the defined regions of proposed nuclear excavations in the Republics of Panama and Colombia. The results of the field surveys conducted in Phase II are presented in this report. Specifically, the data describes the elemental composition of the major components of the ecosystem, and reports the calculated stable element concentration factors for the major food organisms. This data provides baseline values from which predictions can be made of the potential maximum radionuclide intake by populations using this resource.

The purpose of this report is to describe the work accomplished to date in developing and implementing a computer programmed mathematical model for NSS reliability analysis.

This report describes the correlation study of the ultrasonic shearwave inspection of nozzle coolant-channel brazed shear-joints.

This report presents the details of the activities of Douglas United Nuclear at the Hanford site during the month of May 1968.

The efficiency of producing Pu-238 from Np-238 depends on the relative absorption cross sections of the target, Np-237, and the product, Pu-238. A lowering of the Pu-238/Np-237 cross section ratio reduces the destruction of Pu-238 formed during reactor operation. The absorption cross sections of both these isotopes are strongly neutron energy dependent; the absorption cross section of Pu-238 decreases more rapidly with thermal neutron temperature increases than the conventional v{sup {minus}1} dependency and exhibits negligible resonance absorption. On the other hand, Np-237 is a very nearly v{sup {minus}1} thermal neutron absorber and has dominant low level resonance cross sections. Thus, for higher thermal neutron temperatures and a more epithermal neutron spectrum, depletion of the Pu-238 product is reduced relative to Np-237 burnout. The relative absorption cross sections of these two isotopes were calculated for the K and N Reactors as a function of graphite temperature for two linear densitie of neptunium in the target elements for each.reactor type. The method of calculation was as follows: The HAMMER integral transport code was used to obtain region and cell averaged four-group cross sections for both the fuel and target cells. These cross sections were then used in the HFN diffusion theory code …

A primary factor in assessing the impact on the biosphere of the discharge of heated reactor effluent to the Columbia River is the degree of initial dilution. Each of the reactor effluent lines discharges at the bottom of the river, approximately normal to the current, and near the main channel. As part of the Division of Production research and development program titled ``The Effects of Reactor Effluent on the Quality of Columbia River Water,`` the temperature measurements recorded in this document were taken over a period of several years. Generally, the exact locations of the ends of the effluent lines could not be determined from the river. The intent therefore was to determine the initial degree of dilution at the point where the mixed effluent first reached the surface, the so-called ``bubble,`` over a range of river flow-rates. A secondary goal was to determine the distance downstream (in quarter-mile increments) at which vertical mixing of the effluent streams could be considered complete. The data reported here have been partially reported previously and used in the development of a mathematical model of plume development. The purpose of this document is to provide a record of the field data in more detail …

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During the first half of FY-1968, a test irradiation of neptunium was performed in KE Reactor. The basic objectives of this test were to show the reactor capability for irradiating neptunium target elements in an elevated flux; demonstrate the charge-discharge of several of the target columns during reactor operation; and establish the Pu-238 production characteristics of the K-type reactor. These objectives were successfully met. This document reports the results and conclusions derived in meeting the third objective -- establishing K reactor Pu-238 production characteristics.

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Some of the things discussed in this report are: (1) Computation--NAL is now obtaining satisfactory service on NYU's 6600 computer via the telephone data link. Until about two weeks ago we were plagued by numerous breakdowns of the computer itself (one lasting about three weeks), and bugs in the NYU programs that control the transmission. Early this month a two month complete rebuilding of the NYU computer was begun. During this period Control Data Corporation is making a new computer at their Manhattan data center available to NYU and to the remote-terminal users. This computer is reasonably reliable, and the most serious bugs have apparently been removed from the transmission system. NAL now has immediate access to the computer for most of the day and turn-around time for jobs with moderate amounts of output is often less than one hour. We have always received excellent service and help from Argonne's Applied Mathematics Division, which has made its two computers, a CDC 3600 and an IBM 360-75, available to us. At present we have a courier service to Argonne making three trips a day, soon to be extended to five. In addition IBM is furnishing very competent personnel to help convert …

Arguments are presented which suggest that PCAC is generally applicable only in theories where the once-integrated commutator of axial currents is a conserved vector current.

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The annual report on the previous fiscal year`s accomplishments attributed to process development has been provided about six months after the end of the fiscal year. In accordance with a recent request, the date of this report has been advanced to coincide with the end of the fiscal year. Further, the scope of the report has been expanded to include a narrative assessment of program accomplishments. Because of this enlargement of scope some liberty has been taken in identifying new products and development gains. The Douglas United Nuclear process development program can be categorized into the following: (1) Cost Reduction, (2) Increased Plant Life, (3) Versatility, and (4) Safety and Licensability. The overall program goal is to develop technology that will provide greater efficiency at reduced cost and yet be responsive to an increasing variety of product requirements while continuing the excellent plant safety performance. The goal is significant when considered in view of increasing budgetary pressure. The projected defense requirements after 1975 are not expected to require the full capacity of the Hanford reactors. However, based upon the anticipated growth of electric power requirements and space exploration power requirements, the current full productive capacity of the Hanford reactors will …

The objective of the test described in this report is to authorize loading KE Reactor tubes 4396, 4397, 4398, 4496, 4497, 4498, 4596, 4597, and 4598 with 0.947 enriched fuel in support of the X-2 level Battelle Northwest neutron spectrometer, when the spectrometer will be in use.

Progress is reported in these areas: nuclear graphite; fuel development for gas-cooled reactors; HTGR graphite studies; nuclear ceramics; fast-reactor nitrides research; non-destructive testing; metallic fuels; basic swelling studies; ATR gas and water loop operation and maintenance; reactor fuels and materials; fast reactor dosimetry and damage analysis; and irradiation damage to reactor metals.

This report contains the reports of progress and the plans for future work of Douglas United Nuclear, and Atlantic Richfield on the Basic Production Mission. This mission covers the Research and Development work associated with operating the Hanford production complex in its present mode. For the conventional reactors this means primarily the production of weapons-grade plutonium. For the N Reactor this primarily concerns the production of plutonium of 12 percent Pu-240 content, or such other Pu-240 level as may be assigned by the Commission. For Atlantic Richfield this entails isolating and purifying the products of the above described reactor operations. The report describes scope and objectives, progress during report period, evaluation of effort, budget period plans, milestones, references, and statistical summary schedules for the Hanford low pressure reactors, the N reactor, and spent fuel processing activities.

This program is directed to the production of higher weight plutonium isotopes and transplutonium isotopes from the irradiation of transuranic elements, particularly plutonium. Since production of Pu-238 from the irradiation of Np-237 and Am-241 is the subject of Mission 4, Pu-238 Program, it is excluded from this Mission. Specific products which are of prime interest are Cm-244 and plutonium containing a high concentration of either the Pu-240 isotope or the Pu-242 isotope. Because of the potential interest in Cm-244 as a heat source in the 1970`s, the main emphasis has been to provide the capability for producing this isotope. In support of this program, irradiations have been performed to obtain isotopic buildup rates, and a production and economic calculational model has been prepared for determining production methods and costs of producing Cm-244 in the Richland complex. The Richland production reactors have particular advantages in producing higher weight plutonium isotopes from the irradiation of plutonium because of a desirable neutron flux spectrum and a high heat removal capability. Specifically, the high temperature thermal neutron flux maximizes the capture-to-fission ratio of the Pu-239 and Pu-241 isotopes; the high heat removal capability provides for the large decrease in heat generation in the plutonium …

There are three principal facets to the Pu-238 Program which are important to Richland. First, reactor neptunium production rates can be materially enhanced by judicious fuel management plans. Second, significant improvement in production efficiency and costs may be made if the Pu-238 production step (irradiation of Np-237) were sites at Richland. Further, Richland reactors have ample capacity, without reducing power, to irradiate all neptunium from government and commercial reactor sources which has been forecasted well into the 1980`s. Third, a separate Pu-238 production process, that of irradiating Am-241 (obtained from power reactor plutonium returns), offers an attractive and competitive means to materially supplement Pu-238 from the Np-237 route. The first two of these aspects of the Pu-238 Program are being pursued actively, particularly in light of firm and predicted requirements for Pu-238. Technological development for irradiating and processing Am-241 will be performed in the near future.

In anticipation of a continuing trend for reductions in military plutonium requirements, reactor programs at the Richland site are being directed toward other long-term production objectives. For the general case of an alternate reactor product, uranium-238 would be displaced from the reactor by another target material, e.g., lithium (for tritium production) or neptunium-237 (for plutonium-238 production), and the remaining fuel would require higher enrichment (increase of uranium-235 concentration) to maintain reactor reactivity. The operating fuel reprocessing facilities at Hanford were originally designed for the processing of fuels containing less than one percent U-235 (pre-irradiation basis). Today, limited amounts of a ``spike`` fuel, averaging about 1.15 percent U-235, are included in the production load, and demonstration quantities of 2.1 percent enriched coproduct fuels have been processed under special test support conditions. Anticipated reactor programs requiring higher enrichment fuels pose new problems of reprocessing technology. These problems have their bases in the increased U-235 content of the fuel, and in the material and design features provided to obtain a higher specific power in the reactor. The programs required to develop the technological bases for reprocessing proposed Hanford fuels of greater enrichments, generally in excess of one percent U-235, are described by this …

While the safety status of the Richland facilities has in the past been deemed adequate, all aspects of nuclear technology have progressed and evolved including standards of nuclear safety. Hence, the national nuclear safety environment within which the Richland facilities are operated is grossly different now than was the case ten years ago; a commensurate change can be expected in the future. Further, the urgency of national security aspects of Hanford operation seems less acute now than in the past and may become less so in the future. Finally, the isolation of the Hanford site has been reduced by the release of land, and the concentration of people and valuable property in near proximity may increase in the future. While some program modifications and changes in emphasis are to be expected, the five-year outline shown here is considered to be a reasonable representation of the safety work of highest priority to be studied. The Nuclear Safety Program consists of seven, concurrent subprograms. These are: 8RLa--fuel temperature transients under accident conditions; 8RLb--chemical and metallurgical reactions and fission product release from overheated fuel; 8RLc--control of fission gases; 8RLd--meteorological studies; 8RLe--ground fixation of radioactive material in liquid wastes; 8RLf--particle formation and release from …