Three ''gassy'' irradiated uranium dioxide pins were run past failure in a 35-ms natural TREAT transient in TREAT loop Test E3 to guide in choosing between two modeling assumptions regarding energy conversion from sodium vaporization in an irradiated-oxide-fuel/coolant interaction (FCI): (1) The trapped fission gas enhances fuel fragmentation upon failure, accelerates fuel-coolant mixing, and thus promotes an energetic FCI, or, conversely, (2) the trapped fission gas blankets the fuel and reduces the rate of heat transfer to sodium, preventing an energetic FCI.

Cladding failure is one of the major considerations in analysis of fuel-pin behavior during hypothetical accident transients since time, location, and nature of failure govern the early post-failure material motion and reactivity feedback. Out-of-pile thermal transient tests of both irradiated and unirradiated fast-reactor cladding show that local plastic instability, or bulging, often precedes rupture and that the extent of local instability limits the initial rip length. To investigate the details of bulge formation and growth, a perturbation analysis of the equations governing large deformation of a cylindrical shell has been developed, resulting in a set of linear differential equations for the bulge geometry. These equations have been solved along with appropriate constitutive equations and various constraints on the ends of the cladding. Sources for bulge formation that have been considered include initial geometric imperfections and thermal perturbations due to either eccentric fuel pellets or non-symmetric cooling. Of these, only the first is relevant to out-of-pile burst tests. Here it has been found that the most likely imperfection that will grow unstably to failure leads to a bulge around half the circumference with an axial length 1.1 times the deformed diameter. This is in general agreement with burst-test results. For the …

The principal safety-related characteristics of current CANDU-PHW power plants are described, and a distinction between those characteristics which are intrinsic to the CANDU-PHW system and those that are not is presented. An outline is given of the main features of the Canadian safety and licensing approach. Differences between the U.S. and Canadian approach to safety and licensing are discussed. Some of the main results of the safety analyses, routinely performed for CANDU-PHW reactors, are presented. U.S.-NRC General Design Criteria are evaluated as regards their applicability to CANDU-PHW reactors; vice-versa the CANDU-PHW reactor is evaluated with respect to its conformance to the U.S.-NRC General Design Criteria. A number of design modifications are proposed to be incorporated into the CANDU-PHW reactor in order to facilitate its introduction into the U.S.

Annual report of the Argonne National Laboratory Radiological and Environmental Research Division regarding activities related to atmospheric physics.

Annual report of the Argonne National Laboratory Environmental Research Division regarding activities related to ecology and the effects of radiation on the environment.

This document reports on the work done in applied physical chemistry at the Chemical Technology Division (CMT), Argonne National Laboratory (ANL), in the period October 1991 through September 1992. this work includes research into the process that control the release and transport of fission products under accident-like conditions in a light water reactor, the thermophysical properties of the metal fuel in the Integral Fast Reactor under development at ANL, and the properties of candidate tritium breeding materials in environments simulating those of fusion energy systems.

This paper presents an algorithm in PROLOG for compiling recursively computable descriptions of system behavior from computable descriptions of behavior for parts and lists of interconnections. We give a set of conditions that must be satisfied by various data structures in the computation. It seems possible to provide an informal verification (by hand) that these conditions are true also of the output.

Report on an ongoing experimental program to systematically test industrial shell-and-tube exchanger configurations for the occurrence of potentially-damaging tube vibration as a function of flow rate.

This collection of exercises has been prepared to teach the use of the automated reasoning system ITP. Previous knowledge of automated reasoning is not presumed. The exercises are designed for use with the UNIX operating system.

Possible methods for disposing of the immobilized raffinate from TRUEX processing are reviewed. The purpose of the TRUEX process is to extract transuranium elements from high-level and TRU wastes into a small volume that can be managed at lower cost than that of the original wastes. The raffinate from the TRUEX process, containing negligible concentrations of transuranium elements, would be combined with salt solutions also derived from processing high-level waste, and the mixture would be converted to grout.

Metal cutting techniques that can be used to segment the reactor pressure vessel of the Experimental Boiling Water Reactor (EBWR) at Argonne National Laboratory (ANL) have been evaluated by Nuclear Energy Services. Twelve cutting technologies are described in terms of their ability to perform the required task, their performance characteristics, environmental and radiological impacts, and cost and schedule considerations. Specific recommendations regarding which technology should ultimately be used by ANL are included. The selection of a cutting method was the responsibility of the decommissioning staff at ANL, who included a relative weighting of the parameters described in this document in their evaluation process.

In 1956, the Experimental Boiling Water Reactor (EBWR) Facility was first operated at Argonne National Laboratory (ANL) as a test reactor to demonstrate the feasibility of operating an integrated power plant using a direct cycle boiling water reactor as a heat source. In 1967, ANL permanently shut down the EBWR and placed it in dry lay-up. This project plan presents the schedule and organization for the decontamination and decommissioning of the EBWR Facility which will allow it to be reused by other ANL scientific research programs. The project total estimated cost is $14.3M and is projected to generate 22,000 cubic feet of low-level radioactive waste which will be disposed of at an approved DOE burial ground. 18 figs., 3 tabs.

One aspect of Argonne research in parallel computing involves the speed and other properties of parallel SDI algorithms. Various algorithms under study have exhibited speedups resulting from parallelization on shared-memory machines. A weapon-target accessibility algorithm called ACCESS exhibited a high degree of inherent parallelism and has been studied on a wide variety of sequential and parallel multiple instruction multiple data (MIMD) machines. To study ACCESS on a massively parallel single instruction multiple data (SIMD) machine architecture, ANL researchers developed a version of ACCESS on a Thinking Machines Corporation 16K processor Connection Machine-2 (CM-2) located at the ACRF. ANL researchers wrote the Connection Machine version of ACCESS in C(*), a version of C by Thinking Machines Corporation with extensions to accommodate SIMD parallelism. Because of the large number of available physical processors and the ability to create virtual processors on the CM-2, the Connection Machine version of ACCESS was able to process an array of 128 x 1024 tasks in parallel. For the data tested, the CM-2 implementation of ACCESS was faster than both the parallel version run on the Alliant FX/8, the Encore Multimax, and the Sequent Balance and the sequential version run on the ANL Cray X-MP/14. For the …

This paper summarizes our investigations into the computational detection of secondary and tertiary structure of ribosomal RNA. We have developed a new automated procedure that not only identifies potential bondings of secondary and tertiary structure, but also provides the covariation evidence that supports the proposed bondings, and any counter-evidence that can be detected in the known sequences. A small number of previously unknown bondings have been detected in individual RNA molecules (16S rRNA and 7S RNA) through the use of our automated procedure. Currently, we are systematically studying mitochondrial rRNA. Our goal is to detect tertiary structure within 16S rRNA and quaternary structure between 16S and 23S rRNA. Our ultimate hope is that automated covariation analysis will contribute significantly to a refined picture of ribosome structure. Our colleagues in biology have begun experiments to test certain hypotheses suggested by an examination of our program's output. These experiments involve sequencing key portions of the 23S ribosomal RNA for species in which the known 16S ribosomal RNA exhibits variation (from the dominant pattern) at the site of a proposed bonding. The hope is that the 23S ribosomal RNA of these species will exhibit corresponding complementary variation or generalized covariation.

Report on the development of square integrable solutions for Hamiltonian systems in all cases, including intermediate cases.

The complete high-plutonium-240 fuel experiment in ZPPR assembly 4 is reviewed. Results of criticality, enrichment, small-sample perturbation, sodium void, uranium-238 Doppler, control rod substitution and reaction rate measurements are presented. Comparison of these measured values with calculated results are included where possible. The relationship between the ZPPR high-plutonium-240 fuel experiments and the results obtained in previous critical experience is considered.

In the development of lithium-aluminum/iron sulfide secondary cells at Argonne National Laboratory, an instrumentation system was necessary to automatically operate experimental cells over extended periods of times. The system described in this report provides the capability for control of cell cycling and recording of data without the need for constant attendance by research personnel. In these tests, electrical performance, power, energy storage capacity cycle-life and cell lifetimes are determined by repetitive charging and discharging of the cells.

Progress report on water-reactor-safety heat-transfer and flow problems. Covering the following research and development areas: loss-of-coolant accident research, transient fuel response and fission-product release program, mechanical properties of zircaloy containing oxygen, and steam-expulsion studies.

One of the important issues related to fluidized bed combustion of fossil fuels is the subsequent handling and/or treatment of the partially sulfated lime material removed from the combustor. One alternative would be to regenerate the sulfated additive to recover the sulfur, which would be stored for use, and lime that would be recycled for reuse in the combustor. It is the purpose of this report to review the development of regeneration technology which has progressed rather slowly as compared with the technology relative to the fluidized bed combustion process. The review covers research efforts specifically directed toward the regeneration of sulfated limestones plus those studies which have been made to investigate the decomposition of naturally occurring minerals of calcium sulfate. The report reviews basic thermodynamic and kinetic studies as well as laboratory, bench, and pilot scale process development studies. No attempt has been made in the review to evaluate the engineering, environmental, or economic merits of regeneration of the various regeneration schemes.

The corrosive and erosive environments at high temperatures and pressures in coal gasifiers impose severe requirements on the alloys of fabrication. A concise review of the application of ceramic coatings to resist coal-gas environments has been conducted. The purpose of this review is to explore suitable ceramic or cermet materials that may resist or retard the degradation of metal components and to summarize the state of the art of various methods of producing such coatings.

The behavior of FTR-type, mixed-oxide, pre-irradiated "high-power-structure" fuel during a simulation of an FTR loss-of-flow accident was studied in the Mark-IIA integral TREAT loop. Analysis of the data leads to a postulated scenario (sequence and timing) of events in this test. This scenario is presented, together with the calculated timing of events obtained by use of SAS code.

This effort is being directed toward support studies for the national endeavor on in situ coal gasification. This task involves the investigation of reaction-controlling variables and product distributions for the gasification of both coals and chars utilizing steam and oxygen. Included in this task is the investigation of the effects of using brackish water as the water supply. The high-pressure char gasification system has been received from the manufacturer and is currently undergoing testing. The types of experiments that would be most useful in their studies have been discussed with two of the three laboratories carrying out field tests of in-situ gasification.

This paper supplements the Proposed Standard for a Generic Package of Primitive Functions for Ada, '' written by the ISO- IEC/JTC1/SC22/WG9 (Ada) Numerics Rapporteur Group. Based on recommendations made jointly by the ACM SIGAda Numerics Working Group and the Ada-Europe Numerics Working Group, the proposed primitive functions standard is the second of several anticipated secondary standards to address the interrelated issues of portability, efficiency, and robustness of numerical software written in Ada. Its purpose, features, and developmental history are outlined in this commentary.

The only effective way to raise the confidence level of a program significantly is to give a convincing proof of its correctness. But one should not first make the program and then prove its correctness, because then the requirement of providing the proof would only increase the poor programmer's burden. On the contrary: the programmer should let correctness proof and program grow hand in hand.