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in creator/contributor: "Lofaro, R."

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Using data bases to understand aging

A great deal of nuclear power plant operating experience has been documented in the form of national data bases. Individual plant maintenance records, design and manufacturing data, equipment qualification documents, and other published reports provide an enormous amount of information that can characterize a component. This can be of great importance in examining and understanding the effects of aging on plant performance and safety. To obtain meaningful results, however, the strengths and wea… more

Date: January 1, 1988

Creator: Subudhi, M. & Lofaro, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Monitoring of LWR component cooling water systems

As part of the Nuclear Plant Aging Research program, the monitoring methods used for component cooling water (CCW) systems in pressurized water reactors (PWRs) were reviewed and evaluated in terms of their effectiveness at detecting various aging mechanisms. A survey of PWRs was performed to determine what practices are currently used. Monitoring methods for three of the major components in the CCW system were correlated with the aging mechanisms they are able to detect, and generic tables of p… more

Date: January 1, 1991

Creator: Lofaro, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Leak rate analysis of the Westinghouse Reactor Coolant Pump

An independent analysis was performed by ETEC to determine what the seal leakage rates would be for the Westinghouse Reactor Coolant Pump (RCP) during a postulated station blackout resulting from loss of ac electric power. The object of the study was to determine leakage rates for the following conditions: Case 1: All three seals function. Case 2: No. 1 seal fails open while Nos. 2 and 3 seals function. Case 3: All three seals fail open. The ETEC analysis confirmed Westinghouse calculations on … more

Date: July 1, 1985

Creator: Boardman, T.; Jeanmougin, N.; Lofaro, R. & Prevost, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Detecting and mitigating aging in component cooling water systems

The time-dependent effects of aging on component cooling water (CCW) systems in nuclear power plants has been studied and documented as part of a research program sponsored by the US Nuclear Regulatory Commission. It was found that age related degradation leads to failures in the CCW system which can result in an increase in system unavailability, if not properly detected and mitigated. To identify effective methods of managing this degradation, information on inspection, monitoring, and mainte… more

Date: January 1, 1991

Creator: Lofaro, R.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nuclear plant aging study of Residual Heat Removal systems

The effects of aging on Residual Heat Removal systems in Boiling Water Reactors have been studied as part of the Nuclear Plant Aging Research program. The aging phenomena has been characterized by analyzing operating experience from various national data bases. In addition, actual plant data was obtained to supplement and validate the data base findings. Time-dependent failure rates were calculated for several components to identify aging trends. A computer program was developed and implemented… more

Date: January 1, 1988

Creator: Lofaro, R.; Gunther, W.; Subudhi, M. & Taylor, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Understanding aging in containment cooling systems

A study has been performed to assess the effects of aging in nuclear power plant containment cooling systems. Failure records from national databases, as well as plant specific data were reviewed and analyzed to identify aging characteristics for this system. The predominant aging mechanisms were determined, along with the most frequently failed components and their associated failure modes. This paper discusses the aging mechanisms present in the containment spray system and the containment fa… more

Date: December 1, 1993

Creator: Lofaro, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Plant maintenance and aging management: Are they the same?

As part of the NRC`s Nuclear Plant Aging Research Program, a number of aging studies were performed on safety-related systems and components which found that, even with current maintenance and monitoring practices in place, a large number of the reported failures are related to aging. This suggests that current practices are not sufficient to completely manage aging degradation, and other factors need to be considered. This paper examines the aging management process and the degree to which mai… more

Date: June 1, 1995

Creator: Lofaro, R.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Detecting and mitigating aging in component cooling water systems

Date: December 31, 1991

Creator: Lofaro, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Aging assessments: A strategy for today and the future

Aging assessments have been performed for selected nuclear power plant systems under the NRC`s Nuclear Plant Aging Research (NPAR) program. These assessments are typically performed by evaluating industry wide data from national databases. The results provide useful information on the typical aging characteristics for the system studied. However, due to the differences in operation and environmental conditions, as well as maintenance practices between plants, the results of the industry wide da… more

Date: June 1, 1993

Creator: Lofaro, R. & Taylor, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Aging assessment of Residual Heat Removal systems in Boiling Water Reactors

The effects of aging on Residual Heat Removal systems in Boiling Water Reactors have been studied as part of the Nuclear Plant Aging Research Program. The aging phenomena has been characterized by analyzing operating experience from various national data bases. In addition, actual plant data was obtained to supplement and validate the data base findings.

Date: January 1, 1992

Creator: Lofaro, R. J. & Aggarwal, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Reliability assurance for regulation of advanced reactors

The advanced nuclear power plants must achieve higher levels of safety than the first generation of plants. Showing that this is indeed true provides new challenges to reliability and risk assessment methods in the analysis of the designs employing passive and semi-passive protection. Reliability assurance of the advanced reactor systems is important for determining the safety of the design and for determining the plant operability. Safety is the primary concern, but operability is considered i… more

Date: January 1, 1991

Creator: Fullwood, R.; Lofaro, R. & Samanta, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Aging assessment of Residual Heat Removal systems in Boiling Water Reactors

Date: June 1, 1992

Creator: Lofaro, R. J. & Aggarwal, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Reliability assurance for regulation of advanced reactors

Date: December 31, 1991

Creator: Fullwood, R.; Lofaro, R. & Samanta, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Condition Monitoring of Cables Task 3 Report: Condition Monitoring Techniques for Electric Cables

For more than 20 years the NRC has sponsored research studying electric cable aging degradation, condition monitoring, and environmental qualification testing practices for electric cables used in nuclear power plants. This report summarizes several of the most effective and commonly used condition monitoring techniques available to detect damage and measure the extent of degradation in electric cable insulation. The technical basis for each technique is summarized, along with its application, … more

Date: November 30, 2009

Creator: Villaran, M.; Lofaro, R. & na

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Detecting and mitigating aging in component cooling water systems

Date: January 1, 1992

Creator: Lofaro, R. J. & Aggarwal, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Life extension of gas turbines used for power generation

Gas turbines have traditionally been used by electric utilities to supplement generating capacity during peak demand periods. As they age, the utility is faced with the decision of either replacing the units to maintain a reliable source of generating capacity, or extending the life of the units through the use of improved maintenance and monitoring techniques. This paper discusses some of the considerations for extended life operation of gas turbines. To perform this study, actual operating an… more

Date: January 1, 1990

Creator: Lofaro, R. & Villaran, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Literature review of environmental qualification of safety-related electric cables: Literature analysis and appendices. Volume 2

In support of the US NRC Environmental Qualification (EQ) Research Program, a literature review was performed to identify past relevant work that could be used to help fully or partially resolve issues of interest related to the qualification of low-voltage electric cable. A summary of the literature reviewed is documented in Volume 1 of this report. In this, Volume 2 of the report, dossiers are presented which document the issues selected for investigation in this program, along with recommend… more

Date: April 1996

Creator: Lofaro, R.; Bowerman, B. & Carbonaro, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Using Condition Monitoring to Predict Remaining Life of Electric Cables

Electric cables are passive components used extensively throughout nuclear power stations to perform numerous safety and non-safety functions. It is known that the polymers commonly used to insulate the conductors on these cables can degrade with time; the rate of degradation being dependent on the severity of the conditions in which the cables operate. Cables do not receive routine maintenance and, since it can be very costly, they are not replaced on a regular basis. Therefore, to ensure thei… more

Date: March 29, 2001

Creator: Lofaro, R.; Soo, P.; Villaran, M. & Grove, E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Assessment of Cable Aging Using Condition Monitoring Techniques

Electric cables in nuclear power plants suffer degradation during service as a result of the thermal and radiation environments in which they are installed. Instrumentation and control cables are one type of cable that provide an important role in reactor safety. Should the polymeric cable insulation material become embrittled and cracked during service, or during a loss-of-coolant-accident (LOCA) and when steam and high radiation conditions are anticipated, failure could occur and prevent the … more

Date: April 6, 2000

Creator: Grove, E.; Lofaro, R.; Soo, P.; Villaran, M. & Hsu, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Results of a literature review on the environmental qualification of low-voltage electric cables

In the design of nuclear power plants in the US, safety-related electric equipment must be qualified to provide reasonable assurance it can withstand the effects of a design basis event (DBE) and still be able to perform its prescribed safety function, even if the accident were to occur at the end of its service life. The requirement for environmental qualification (EQ) originates from the General Design Criteria in the Code of Federal Regulations, Title 10, Part 50 (10 CFR 50). The acceptable … more

Date: December 31, 1995

Creator: Lofaro, R.; Lee, B.; Villaran, M.; Gleason, J. & Aggarwal, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Workshop on environmental qualification of electric equipment

Questions concerning the Environmental Qualification (EQ) of electrical equipment used in commercial nuclear power plants have recently become the subject of significant interest to the US Nuclear Regulatory Commission (NRC). Initial questions centered on whether compliance with the EQ requirements for older plants were adequate to support plant operation beyond 40 years. After subsequent investigation, the NRC Staff concluded that questions related to the differences in EQ requirements between… more

Date: May 1, 1994

Creator: Lofaro, R.; Gunther, W.; Villaran, M.; Lee, B. S. & Taylor, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The effects of age on nuclear power plant containment cooling systems

A study was performed to assess the effects of aging on the performance and availability of containment cooling systems in US commercial nuclear power plants. This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program… more

Date: April 1, 1994

Creator: Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A. & Davis, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Aging and condition monitoring of electric cables in nuclear power plants

There are a variety of environmental stressors in nuclear power plants that can influence the aging rate of components; these include elevated temperatures, high radiation fields, and humid conditions. Exposure to these stressors over long periods of time can cause degradation of components that may go undetected unless the aging mechanisms are identified and monitored. In some cases the degradation may be mitigated by maintenance or replacement. However, some components receive neither and are… more

Date: May 1998

Creator: Lofaro, R. J.; Grove, E. & Soo, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The effects of aging in component cooling water systems and the implications for life extension

To help assess the effects of aging on safety and reliability, an aging and life extension analysis of component cooling water (CCW) systems in pressurized water reactors (PWRs) has been performed as part of the Nuclear Plant Aging Research (NPAR) program. The NPAR program is sponsored by the NRC Office of Research to provide a technical basis for understanding and managing the effects of aging degradation in nuclear plant applications. The objectives of the two phase CCW system analysis are to… more

Date: January 1, 1991

Creator: Lofaro, R.; Taylor, J. (Brookhaven National Lab., Upton, NY (USA)) & Aggarwal, S. (Nuclear Regulatory Commission, Washington, DC (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department