Paul D Ewing

Cybersecurity through Real-Time Distributed Control Systems

Critical infrastructure sites and facilities are becoming increasingly dependent on interconnected physical and cyber-based real-time distributed control systems (RTDCSs). A mounting cybersecurity threat results from the nature of these ubiquitous and sometimes unrestrained communications interconnections. Much work is under way in numerous organizations to characterize the cyber threat, determine means to minimize risk, and develop mitigation strategies to address potential consequences. While it seems natural that a simple application of cyber-protection methods derived from corporate business information technology (IT) domain would lead to an acceptable solution, the reality is that the characteristics of RTDCSs make many of those methods inadequate and unsatisfactory or even harmful. A solution lies in developing a defense-in-depth approach that ranges from protection at communications interconnect levels ultimately to the control system s functional characteristics that are designed to maintain control in the face of malicious intrusion. This paper summarizes the nature of RTDCSs from a cybersecurity perspec tive and discusses issues, vulnerabilities, candidate mitigation approaches, and metrics.

Measurement accuracy limitation analysis on synchrophasors

This paper analyzes the theoretical accuracy limitation of synchrophasors measurements on phase angle and frequency of the power grid. Factors that cause the measurement error are analyzed, including error sources in the instruments and in the power grid signal. Different scenarios of these factors are evaluated according to the normal operation status of power grid measurement. Based on the evaluation and simulation, the errors of phase angle and frequency caused by each factor are calculated and discussed.

Current research results on the technical basis for environmental qualification of safety-related digital I&C hardware in nuclear power plants

Abstract This paper presents progress to date of an NRC-sponsored confirmatory research program initiated to address hardware issues associated with the use of safety-related digital instrumentation and control (I&C) hardware in nuclear power plants. In particular, the potential vulnerability of digital technology to environmental stress effects and means for establishing environmental compatibility for digital I&C systems were studied. The research approach involved evaluating existing military and industrial guidance, identifying the most significant environmental stressors and, for advanced I&C systems in nuclear power plants, investigating the likely failure modes—both at the integrated circuit and system level—for digital technologies under varying levels of environmental stress. Environmental stressors used in the studies included smoke exposure, electromagnetic and radio-frequency interference (EMI/RFI), temperature, and humidity. The insights gained from these studies are being used to recommend appropriate methods for qualifying safety-related digital equipment in nuclear power plants. To characterize the EMI/RFI environment at current LWRs and to estimate the expected environment at ALWRs, ORNL conducted a long-term survey of ambient electromagnetic conditions at several nuclear power plants. A representative sampling of power plant conditions (reactor type, operating mode, site location) were monitored over extended observation periods (e.g., continuous measurements for up to 5 weeks at a single location) were selected to more completely determine the characteristic electromagnetic environment for nuclear power plants. The results of this study contributed to the technical basis for a Nuclear Regulatory Commission Draft Regulatory Guide (DG-1029) issued for comment in 1998.

Parameter correlation of impulse shapes using two-port synthesis

The authors derive equations for determining the time constants of the double exponential impulse from the commonly used parameters for several standard test impulses. They then proceed to synthesize a resistor-capacitor (RC) prototype circuit that will produce the desired impulse. The prototype network is realized through a computer-aided design (CAD) procedure using Cauers RC ladder two-port synthesis method. Descriptions of prototype circuits and test data comparing the theoretical and experimental impulse shapes are also included. The results are a simplified method for determining time constants of a double exponential function from given impulse parameters and a method for deriving the component values for prototype circuits. >

Impact of measurement errors on synchrophasor applications

Data from phasor measurement units (PMUs) inform powerful diagnostic tools that can help avert catastrophic failures in the power grid. Because of this, understanding PMU measurement errors is particularly valuable. This paper examines internal and external factors contributing to PMU phase angle and frequency measurement errors and gives a reasonable explanation for each. Based on these explanations, the impact of those measurement errors on several synchrophasor applications are analyzed: event location detection, oscillation detection, islanding detection, and dynamic line rating.

A pocket-size broadband electric field detection and storage device

The radio-frequency (RF) dosimeter developed by the Oak Ridge National Laboratory is described. It is a portable, pocket-sized, cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. Features of the RF dosimeter include a frequency range of 30 MHz to 10 GHz and a three-dimensional sensor. Data obtained with the RF dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to 6 months, after which the data are transferred to a computer by means on the dosimeters serial port.<<ETX>>

Tracking electric field exposure levels through radio frequency dosimetry

The radio-frequency (RF) dosimeter developed by the Oak Ridge National Laboratory is a portable, pocket-sized cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. The features of the RF dosimeter are described. Data obtained with the RF dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to six months. The proposed specifications for the RF dosimeter included a sensitivity range of 1 to 1000 mW/cm/sup 2/, an audible alarm for fields >8 mW/cm,/sup 2/, integration of dosage for later readout, autoranging capability, and a possible self-powering capability. The design process, starting with the sensor, is detailed, and the tests completed on the final product are described.<<ETX>>