[en] The purpose of this paper is to describe the BNL review process applied to the reliability analyses of Auxiliary Feedwater Systems (AFWS) submitted by operating license applicants to NRC in order to satisfy the pertinent Standard Review Plan requirements. Some generic comments on the availability characteristics of the AFWS are also presented. This work represents an application of a quantitative reliability goal to the regulatory process

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No abstract available

[en] The stress analysis performed on the 1''-PCC-76-A piping system inside containment penetration S-1A is described. Deadweight, thermal expansion, and seismic loads were considered. Results of this analysis show that the subject piping system will meet ASME Boiler and Pressure Vessel Code, Section III, Class 2 requirements provided that supports S8 and S9 are installed as recommended

[en] Operation of L Reactor will necessitate annual cleaning of the L Area 186 basins. Alternatives are presented for sediment discharge due to 186-basin cleaning activities as a basis for choosing the optimal cleaning method. Current cleaning activities (i.e. removal of accumulated sediments) for the P, C and K-Area 186 basins result in suspended solids concentrations in the effluent waters above the NPDES limits, requiring an exemption from the NPDES permit for these short-term releases. The objective of mitigating the 186-basin cleaning activities is to decrease the suspended solids concentrations to within permit limits while continuing satisfactory operation of the basins

[en] EDF operates 6 km of safety-classified steel cylinder reinforced concrete pipelines spread over 8 PWR nuclear reactors located on the sea coast. These pipelines, placed in galleries, convey approximately 3000 m³/h of sea water under a pressure of 4 bar. They have been in operation since the mid eighties or early nineties. Their service life is limited by different scenarios of corrosion by pitting due to the presence of chlorides from sea water. Pipelines are subjected to frequent visual checks that can lead to immediate temporary reinforcement and subsequent replacement. In addition, a diagnosis methodology was developed in order to better anticipate the maintenance operations and in order to assess the remaining service life of pipelines. This methodology combines autopsies of replaced pipes with periodic campaigns of exhaustive half-cell potential mapping. For exhaustive campaigns, the grid spacing was 30 cm x 30 cm, refined to 10 cm x 10 cm in singular zones, on the entire external concrete surface of pipelines, which represents around 6x10⁵ measurement points for 6 km of pipelines. Robust specifications were drawn up for the measurement method and the interpretation of the results, initially based on RILEM and ASTM recommendations and then significantly reinforced based on operational feedback. These specifications ensure the implementation and the interpretation of half-cell potential mapping can be carried out on a very large scale and enable the comparison of results between successive campaigns. The diagnosis methodology was a decisive factor in the planning of a preventive maintenance strategy which would enable a pipeline service life of 60 years. (authors)

[en] The Service Water Assistance Program was developed to provide utility service water system engineers with a mechanism to quickly and efficiently address service water issues. Since its inception, its ability to assist utilities has resulted in a reduction in the operations and maintenance costs associated with service water systems and has provided a medium for EPRI awareness of industry service water issues

[en] It has been known that drain pumps in nuclear power plants may suffer cavitation under transient turbine load reductions. Although increasing the size and height of the drain tank can prevent it, such provisions are often not practical, and in some instances even not possible. The paper presented explores some conceptual protective methods, and briefly discusses their pros and cons as applied to both drain pumping forward and backward systems. The method of quantitative determination of design parameters required for each protective method is either referred to or derived. Based on simplicity, economy, and reliability, it is concluded that the drain tank pressure decay control system appears to be the most promising protective method for the drain pumping forward system, whereas either the continuous feedwater injection system or the continuous drain subcooling system is the optimum method for the drain pumping backward system

[en] The purpose of the review was to examine all remaining lines of the LOFT emergency core coolant facility piping outside of containment and with a diameter of less than two inches, not analyzed by ITT Grinnell Corporation. Because of a discrepancy on the Grinnell analysis, lines 3''-ECCV-10-A, 2''-ECCV-10-A and 2''-ECCV-11-A were included in this review. In addition, some lines from other systems which connected to the ECC piping were also examined, as listed on the isometric sketches in this report. An on-site ''walk-through'' was made first to verify existing restraint and valve locations. Very short stub lines were eliminated by inspection. All remaining lines, together with the lines analyzed by Grinnell and lines being currently analyzed by R. M. Fors of the Applied Mechanics Branch constitute a complete analysis of the ECC facility piping as now listed in LOFT Specification P-1, Line Designation Tables

No abstract available