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Detection and mitigating rod drive control system degradation in Westinghouse PWRs

Description: A study of the effects of aging on the Westinghouse Control Rod Drive (CRD) System was performed as part of the US NRC's Nuclear Plant aging Research (NPAR) Program. For the study, the CRD system boundary includes the power and logic cabinets associated with the manual control rod movement, and the control rod mechanism itself. The aging-related degradation of the interconnecting cables and connectors and the rod position indicating system also were considered. This paper presents the results of that study pertaining to the electrical and instrumentation portions of the CRD system including ways to detect and mitigate system degradation.
Date: January 1, 1990
Creator: Gunther, W. & Sullivan, K.
Partner: UNT Libraries Government Documents Department

Updating the NRC Standard Review Plan - Chapter 8 - Electrical Systems

Description: The Standard Review Plan (SRP) (Reference 2), provides guidance to the regulatory staff of the Nuclear Regulatory Commission (NRC) on performing their safety reviews of applications to construct or operate nuclear power plants, and applications to approve standard designs and sites for nuclear power plants. Chapter 8 of the SRP provides guidance related to the review of station electrical distribution systems described by the applicant in its Design Control Document (DCD) or Safety Analysis Report (SAR). As part of the 2006-2007 SAR update, all sections in this Chapter (8.1, 8.2, 8.3.1, 8.3.2, Appendix 8A, and Appendix 8B) were revised to incorporate new analyses, design approaches, and the lessons learned from the review of the AP 1000 design certification and to assure consistency with the draft Regulatory Guide DG-1145, ''Combined License Applications for Nuclear Power Plants (LWR Edition)''.
Date: June 24, 2007
Creator: Sullivan, K.
Partner: UNT Libraries Government Documents Department

Glass and ceramic immobilization alternatives and the use of new facilities

Description: The Department of Energy (DOE) is examining options for placing weapons-usable surplus nuclear materials (principally plutonium [Pu] and highly enriched uranium [U]) in a form or condition that is substantially and inherently more difficult to use in weapons either by the Host Country or by a subnational group. The two most promising alternatives for achieving these aims are: fabrication and use as fuel, without reprocessing, in existing or modified nuclear reactors; or vitrification in combination with high-level radioactive waste. The mission of the immobilization technologies and facilities considered in this paper and the paper ``Use of Savannah River Site (SRS) Facilities for Glass and Ceramics,`` is to produce a waste form by incorporating plutonium in either an amorphous glass or a crystalline ceramic matrix and then disposal of it in a geologic repository. This paper summarizes all the glass and ceramic alternatives under consideration and presents the immobilization options using new facilities. The subsequent paper presents the immobilization options which use existing facilities at the Savannah River Site.
Date: December 31, 1995
Creator: Kan, T. & Sullivan, K.
Partner: UNT Libraries Government Documents Department

Aging mechanisms in the Westinghouse PWR (Pressurized Water Reactor) Control Rod Drive system

Description: An aging assessment of the Westinghouse Pressurized Water Reactor (PWR) Control Rod System (CRD) has been completed as part of the US NRC's Nuclear Plant Aging Research, (NPAR) Program. This study examined the design, construction, maintenance, and operation of the system to determine its potential for degradation as the plant ages. Selected results from this study are presented in this paper. The operating experience data were evaluated to identify the predominant failure modes, causes, and effects. From our evaluation of the data, coupled with an assessment of the materials of construction and the operating environment, we conclude that the Westinghouse CRD system is subject to degradation which, if unchecked, could affect its safety function as a plant ages. Ways to detect and mitigate the effects of aging are included in this paper. The current maintenance for the control rod drive system at fifteen Westinghouse PWRs was obtained through a survey conducted in cooperation with EPRI and NUMARC. The results of the survey indicate that some plants have modified the system, replaced components, or expanded preventive maintenance. Several of these activities have effectively addressed the aging issue. 2 refs., 2 figs., 2 tabs.
Date: January 1, 1991
Creator: Gunther, W. & Sullivan, K.
Partner: UNT Libraries Government Documents Department

Effect of component aging on PWR control rod drive systems

Description: An aging assessment of PWR control rod drive (CRD) systems has been completed as part of the US NRC Nuclear Plant Aging Research (NPAR) Program. The design, construction, maintenance, and operation of the Babcock Wilcox (B W), Combustion Engineering (CE), and Westinghouse (W) systems were evaluated to determine the potential for degradation as each system ages. Operating experience data were evaluated to identify the predominant failure modes, causes, and effects. This, coupled with an assessment of the materials of construction and operating environment, demonstrate that each design is subject to degradation, which if left unchecked, could affect its safety function as the plant ages. An industry survey, conducted with the assistance of EPRI and NUMARC, identified current CRD system maintenance and inspection practices. The results of this survey indicate that some plants have performed system modifications, replaced components, or augmented existing preventive maintenance practices in response to system aging. The survey results also supported the operating experience data, which concluded that the timely replacement of degraded components, prior to failure, was not always possible using existing condition monitoring techniques. The recommendations presented in this study also include a discussion of more advanced monitoring techniques, which provide trendable results capable of detecting aging.
Date: January 1, 1992
Creator: Grove, E.; Gunther, W. & Sullivan, K.
Partner: UNT Libraries Government Documents Department

Effect of component aging on PWR control rod drive systems

Description: An aging assessment of PWR control rod drive (CRD) systems has been completed as part of the US NRC Nuclear Plant Aging Research (NPAR) Program. The design, construction, maintenance, and operation of the Babcock & Wilcox (B & W), Combustion Engineering (CE), and Westinghouse (W) systems were evaluated to determine the potential for degradation as each system ages. Operating experience data were evaluated to identify the predominant failure modes, causes, and effects. This, coupled with an assessment of the materials of construction and operating environment, demonstrate that each design is subject to degradation, which if left unchecked, could affect its safety function as the plant ages. An industry survey, conducted with the assistance of EPRI and NUMARC, identified current CRD system maintenance and inspection practices. The results of this survey indicate that some plants have performed system modifications, replaced components, or augmented existing preventive maintenance practices in response to system aging. The survey results also supported the operating experience data, which concluded that the timely replacement of degraded components, prior to failure, was not always possible using existing condition monitoring techniques. The recommendations presented in this study also include a discussion of more advanced monitoring techniques, which provide trendable results capable of detecting aging.
Date: June 1, 1992
Creator: Grove, E.; Gunther, W. & Sullivan, K.
Partner: UNT Libraries Government Documents Department

Carbon dioxide, hydrographic, and chemical data obtained during the R/V Thomas Washington TUNES-1 in the equatorial Pacific Ocean (WOCE Section P17C)

Description: This report discusses the procedures and methods used to obtain measurements of total carbon dioxide (TCO{sub 2}), total alkalinity (TALK), and radiocarbon ({Delta} {sup 14}C), as well as hydrographic and chemical data, during the Research Vessel Thomas Washington Expedition TUNES-1 in the Equatorial Pacific Ocean (Section P17C). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in San Diego, California, on May 31, 1991, and ended in Papeete, Tahiti, on July 11, 1991. WOCE Meridional Section P17C, along 135{degree}W and between {approximately}5{degree}S and 36{degree}N, was completed during the 42-day expedition. All 123 hydrographic stations (including 9 large-volume stations) were completed to the full water-column depth. Spacing between stations was 30 nautical miles, except between 3{degree}N and 3{degree}S, where it was 10 nautical miles. At 30 stations, CO{sub 2} measurements were provided for the US Department of Energy`s Carbon Dioxide Program. Hydrographic and chemical measurements made along WOCE Section P17C included pressure, temperature, salinity, and oxygen (measured by conductivity, temperature, and depth sensor), as well as bottle measurements of salinity, oxygen, phosphate, nitrate, nitrite, silicate, chlorofluorocarbon (CFC)-11, CFC-12, {Delta} {sup 14}C, TCO{sub 2}, and TALK. In addition, potential temperatures were calculated from the measured variables.
Date: June 1, 1997
Creator: Goyet, C.; Key, R.M.; Sullivan, K.F.; Tsuchiya, M. & Kozyr, A.
Partner: UNT Libraries Government Documents Department

Modification of the CEBAF transport dipoles for energy upgrade considerations

Description: The CEBAF accelerator at the Thomas Jefferson National Accelerator Facility contains 415 resistive dipoles in the recirculation arcs and transport lines. These dipoles were originally designed and magnetically mapped to support the operation of the accelerator at 6 GeV. Recent interests in upgrading the CEBAF energy beyond 6 GeV prompted a study into operating the dipoles beyond their design limits. Finite element modeling was performed to quantify saturation effects at higher currents and to test simple modifications to improve magnetic performance. For confirmation, various steps were prototyped and magnetically measured. Measurement results agreed with finite element models and showed that saturation could be reduced to manageable levels. It was found that the most populous dipole families could be modified to reach twice their design field with minimal cost and effort. At these higher fields, the magnets operate at a reasonable thermal state with minimal saturation losses a nd little degradation in field quality. Work continues on studying the smaller population of dipoles to determine their performance at higher fields.
Date: March 1, 1999
Creator: Bullard, D.; Harwood, L.; Hiatt, T.; Karn, J.; Martin, E.; Oren, W. et al.
Partner: UNT Libraries Government Documents Department

A Linear RFQ Ion Trap for the Enriched Xenon Observatory

Description: The design, construction, and performance of a linear radio-frequency ion trap (RFQ) intended for use in the Enriched Xenon Observatory (EXO) are described. EXO aims to detect the neutrinoless double-beta decay of {sup 136}Xe to {sup 136}Ba. To suppress possible backgrounds EXO will complement the measurement of decay energy and, to some extent, topology of candidate events in a Xe filled detector with the identification of the daughter nucleus ({sup 136}Ba). The ion trap described here is capable of accepting, cooling, and confining individual Ba ions extracted from the site of the candidate double-beta decay event. A single trapped ion can then be identified, with a large signal-to-noise ratio, via laser spectroscopy.
Date: January 14, 2008
Creator: Flatt, B.; Green, M.; Wodin, J.; DeVoe, R.; Fierlinger, P.; Gratta, G. et al.
Partner: UNT Libraries Government Documents Department

A Liquid Xenon Ionization Chamber in an All-fluoropolymer Vessel

Description: A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of ultra-clean fluoropolymer. We describe the advantages in terms of low radioactivity contamination, provide some details of the construction techniques, and show the energy resolution achieved with a prototype all-fluoropolymer ionization detector.
Date: February 26, 2007
Creator: LePort, F.; Pocar, A.; Bartoszek, L.; DeVoe, R.; Fierlinger, P.; Flatt, B. et al.
Partner: UNT Libraries Government Documents Department