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in creator/contributor: "Kot, C. A."

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HDR (Heissdampfreaktor) Phase 2 vibrational experiments

As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level shaker tests (SHAG) were performed during June and July 1986. The purpose of these experiments is to investigate full-scale structural response, soil-structure interaction, and piping and equipment response under strong excitation conditions. While global safety considerations imposed load limitations, the HDR soil/structure system was nevertheless test… more

Date: October 1, 1986

Creator: Malcher, L. & Kot, C.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Air blast effects on concrete walls

The effects of airblast due to explosive detonation in close proximity of a concrete wall are investigated analytically. Estimates are obtained both for the spalling of the back-face of the concrete wall and for the overall wall response produced by the total impulsive load of the air blast. Assuming elastic wave propagation in the concrete wall, it is found that as spall thickness increases the spall velocity decreases. This holds for normal as well as oblique wave incidence on the back-face o… more

Date: July 1, 1976

Creator: Kot, C. A. & Turula, P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Computing the effect of plastic deformation of piping on pressure transient propagation. [LMFBR]

The computer program PTA-1 performs pressure-transient analysis of large piping networks using the one-dimensional method of characteristics applied to a fluid-hammer formulation. The effect of elastic-plastic deformation of piping on pulse propagation is included in the computation. Each pipe is modeled as a series of rings, neglecting axial effects, bending moments, and inertia. The fluid wave speed is a function of pipe deformation and, consequently, of position and time. Comparison with exi… more

Date: January 1, 1977

Creator: Youngdahl, C.K. & Kot, C.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

PTA-1 computer program for treating pressure transients in hydraulic networks including the effect of pipe plasticity. [LMFBR]

Pressure pulses in the intermediate sodium system of a liquid-metal-cooled fast breeder reactor, such as may originate from a sodium/water reaction in a steam generator, are propagated through the complex sodium piping network to system components such as the pump and intermediate heat exchanger. To assess the effects of such pulses on continued reliable operation of these components and to contribute to system designs which result in the mitigation of these effects, Pressure Transient Analysis… more

Date: January 1, 1977

Creator: Youngdahl, C.K. & Kot, C.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Two-dimensional fluid-hammer analysis by the method of nearcharacteristics

A numerical technique based on the method of nearcharacteristics is considered for solving propagation of fluid-hammer waves in a two-dimensional geometry. The solution is constructed by relating flow conditions by compatibility equations along lines called nearcharacteristics. Three choices are considered in the numerical scheme that are accurate within an error of the order of magnitude of the time step. Since the nearcharacteristics lie in the coordinate planes, the technique provides an eff… more

Date: May 1, 1975

Creator: Shin, Y.W. & Kot, C.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Computation of the effect of pipe plasticity on pressure-pulse propagation in a fluid system

No Description Available.

Date: April 1, 1975

Creator: Youngdahl, C.K. & Kot, C.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Vibrational experiments at the HDR (Heissdampfreaktor): SHAG results and planning for SHAM

As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level shaker tests (SHAG) were performed during June and July 1986 using a coast-down shaker capable of generating 1000 tons of force. The purpose of these experiments was to investigate full-scale structural response, soil/structure interaction, and piping and equipment response under strong excitation conditions. While global safety considerations imposed l… more

Date: January 1, 1987

Creator: Kot, C.A.; Malcher, L. & Steinhilber, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The in-depth safety assessment (ISA) pilot projects in Ukraine.

Ukraine operates pressurized water reactors of the Soviet-designed type, VVER. All Ukrainian plants are currently operating with annually renewable permits until they update their safety analysis reports (SARs). After approval of the SARS by the Ukrainian Nuclear Regulatory Authority, the plants will be granted longer-term operating licenses. In September 1995, the Nuclear Regulatory Authority and the Government Nuclear Power Coordinating Committee of Ukraine issued a new contents requirement f… more

Date: February 10, 1998

Creator: Kot, C. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Vibrational experiments at the HDR (Heissdampfreaktor) German/US cooperation

As part of an overall effort on the validation of seismic calculational methods, the US NRC/RES is collaborating with the Kernforschungszentrum Karlsruhe, FRG, in the vibrational/earthquake experiments conducted at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG. In the most recent experiments (SHAG), high level excitations were produced in the HDR by means of an eccentric-mass coastdown shaker capable of developing 1000 tons of force. The purpose of the experiments was to investiga… more

Date: April 1, 1987

Creator: Kot, C.A.; Malcher, L. & Costello, J.F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pressure transient analysis in piping systems including the effects of plastic deformation and cavitation. [PTA-2 code]

Computational methods for analyzing pressure transients in the intermediate heat transport system of a sodium-cooled breeder reactor are being developed at Argonne National Laboratory. Because these systems typically operate at low pressures, thin-walled piping is used. Consequently, the pressure pulses produced by a sodium/water reaction in a steam generator or a pipe break may plastically deform sections of the piping, and rarefaction waves, because of the low operating pressure, may produce … more

Date: March 1, 1978

Creator: Youngdahl, C.K.; Kot, C.A. & Valentin, R.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Risk methodologies for offsite hazardous materials

A number of suggestions have been advanced in recent years concerning the risks posed to nuclear power plants by offsite hazardous materials relative to (1) the regulatory approach including considerations of minimum and safe standoff distances, exclusion distances, site acceptance ceilings and floors, screening distances and screening probabilities, plant design, etc., and (2) the analysis and evaluation procedures such as material screening criteria, plant vulnerability, standarized physical … more

Date: January 1, 1983

Creator: Kot, C.A.; Eichler, T.V. & Wiedermann, A.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect of initial fluid-system pressures on the behavior of a rupture-disc pressure-relief device

Rupture disc assemblies are used in piping network systems as a pressure-relief device to protect the system from being exposed to excess pressures. Among the various disc assemblies, the reverse-buckling type is chosen for application in the Clinch River Breeder Reactor. This rupture-disc assembly consists of a portion of a thin spherical shell with its convex side subjected to the fluid system. The reverse-buckling type rupture disc assemblies have been used successfully in environments where… more

Date: 1983~

Creator: Hsieh, B. J.; Shin, Y. W. & Kot, C. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Verification of experimental modal modeling using HDR (Heissdampfreaktor) dynamic test data

Experimental modal modeling involves the determination of the modal parameters of the model of a structure from recorded input-output data from dynamic tests. Though commercial modal analysis algorithms are being widely used in many industries their ability to identify a set of reliable modal parameters of an as-built nuclear power plant structure has not been systematically verified. This paper describes the effort to verify MODAL-PLUS, a widely used modal analysis code, using recorded data fr… more

Date: January 1, 1983

Creator: Srinivasan, M.G.; Kot, C.A. & Hsieh, B.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Vibration testing and analysis of a multiply supported piping system

The behavior of nuclear power plant piping systems during earthquake, and the most appropriate and economical mode of supporting such piping, is an issue of major concern. Consequently, the verification and validation of piping analysis methods and assumptions used in the design and safety assessment of nuclear power plants are of great interest. As part of its program on the validation of seismic calculational methods the US Nuclear Regulatory Commission (NRC) is specifically interested in the… more

Date: January 1, 1987

Creator: Hsieh, B.J.; Kot, C.A. & Srinivasan, M.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect of expansion tanks and Tee losses on pressure transients: preliminary parameter study

No Description Available.

Date: October 1, 1974

Creator: Kot, C.A.; Srinivasan, M.G. & Youngdahl, C.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Response of HDR-VKL piping system to seismic test excitations: Comparison of analytical predictions and test measurements

As part of the earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, simulated seismic tests (SHAM) were performed during April--May 1988 on the VKL (Versuchskreislauf) piping system. The purpose of these experiments was to study the behavior of piping subjected to a range of seismic excitation levels including those that exceed design levels manifold and that might induce failure of pipe supports or plasticity in the pipe runs, and to establish seismic margi… more

Date: January 1, 1989

Creator: Srinivasan, M. G.; Kot, C. A. & Hsieh, B. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Investigation of superstructure damping identification for the HDR containment building

A method for the estimation of first mode structural damping, developed by other investigators, was applied to shaker test data of the HDR containment building. Due to inadequate precision in the experimental phase measurements no valid results could be obtained. Based on modal analysis it was also noted that for systems such as the HDR building, contributions of higher modes are not negligible as was assumed in the original approach. Therefore, the procedure for the determination of superstruc… more

Date: January 1, 1985

Creator: Hsieh, B. J.; Kot, C. A. & Srinivasan, M. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of dynamic testing of as-built civil engineering structures

This paper summarizes an evaluation of dynamic tests performed on large as-built structures. The objectives and methods (excitation and data analysis) of tests are reviewed. The utility and limitations of dynamic testing in light of actual experience is discussed. Though low-level tests in themselves will not be useful for predicting structural response to strong ground motion, they are useful for verifying linear models and for clarifying physical phenomena related to soil-structure interactio… more

Date: January 1, 1985

Creator: Srinivasan, M. G.; Kot, C. A. & Hsieh, B. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Comparison of analysis and vibration test results for a multiple supported piping system

The behavior of a nuclear power plant piping system subjected to high level vibrational excitation is investigated experimentally and analytically. The objective is to evaluate the piping analysis method employed in the SMACS computer code. Experimental data are obtained from the Large Shaker Experiments (SHAG) conducted at the HDR Test Facility in Kahl/Main, FRG, in which the dynamic behavior of an in-plant piping system with various support configurations was investigated. Comparisons of calc… more

Date: January 1, 1989

Creator: Hsieh, B. J.; Kot, C. A. & Srinivasan, M. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Comparison of test and earthquake response modeling of a nuclear power plant containment building

The reactor building of a BWR plant was subjected to dynamic testing, a minor earthquake, and a strong earthquake at different times. Analytical models simulating each of these events were devised by previous investigators. A comparison of the characteristics of these models is made in this paper. The different modeling assumptions involved in the different simulation analyses restrict the validity of the models for general use and also narrow the comparison down to only a few modes. The dynami… more

Date: January 1, 1985

Creator: Srinivasan, M. G.; Kot, C. A. & Hsieh, B. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Validation needs of seismic probabilistic risk assessment (PRA) methods applied to nuclear power plants

An effort to validate seismic PRA methods is in progress. The work concentrates on the validation of plant response and fragility estimates through the use of test data and information from actual earthquake experience. Validation needs have been identified in the areas of soil-structure interaction, structural response and capacity, and equipment fragility. Of particular concern is the adequacy of linear methodology to predict nonlinear behavior. While many questions can be resolved through th… more

Date: January 1, 1985

Creator: Kot, C. A.; Srinivasan, M. G. & Hsieh, B. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect of damage on the modal parameters of a cylindrical shell

The objective of the study was to investigate the feasibility of assessing damage to structural systems by measuring the changes in the dynamic characteristics of a thin circular cylindrical shell with both ends open. Theoretical and experimental modal analyses were performed for the shell. Subsequently, a notch was machined into the shell simulating a small amount of damage. The shell with the notch was again subjected to experimental modal analysis. A comparison of the modal parameters determ… more

Date: January 1, 1992

Creator: Srinivasan, M.G. & Kot, C.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A structural design and analysis of a piping system including seismic load

The structural design/analysis of a piping system at a nuclear fuel facility is used to investigate some aspects of current design procedures. Specifically the effect of using various stress measures including ASME Boiler Pressure Vessel (B PV) Code formulas is evaluated. It is found that large differences in local maximum stress values may be calculated depending on the stress criterion used. However, when the global stress maximum for the entire system are compared the differences are much sm… more

Date: January 1, 1991

Creator: Hsieh, B.J. & Kot, C.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Requalification analysis of a circular composite slab for seismic load

The circular roof slab of an existing facility was analyzed to requalify the structure for supporting a significant seismic load that it was not originally designed for. The slab has a clear span of 66 ft and consists of a 48 in thick reinforced concrete member and a steel liner plate. Besides a number of smaller penetrations, the slab contains two significant cutouts: a 9 ft square opening and a 3 ft dia hole. The issues that complicated the analysis of this non-typical structure, i.e., compos… more

Date: November 1, 1992

Creator: Srinivasan, M. G. & Kot, C. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department