Results 1 - 10 of 130
Results 1 - 10 of 130. Search took: 0.019 seconds
|Sort by: date | relevance|
[en] The Technical Area V (TA-V) Seismic Assessment Report was commissioned as part of Sandia National Laboratories (SNL) Self Assessment Requirement per DOE O 414.1, Quality Assurance, for seismic impact on existing facilities at Technical Area-V (TA-V). SNL TA-V facilities are located on an existing Uniform Building Code (UBC) Seismic Zone IIB Site within the physical boundary of the Kirtland Air Force Base (KAFB). The document delineates a summary of the existing facilities with their safety-significant structure, system and components, identifies DOE Guidance, conceptual framework, past assessments and the present Geological and Seismic conditions. Building upon the past information and the evolution of the new seismic design criteria, the document discusses the potential impact of the new standards and provides recommendations based upon the current International Building Code (IBC) per DOE O 420.1B, Facility Safety and DOE G 420.1-2, Guide for the Mitigation of Natural Phenomena Hazards for DOE Nuclear Facilities and Non-Nuclear Facilities.
[en] The paper focuses on the optimization of the test and maintenance intervals under the criteria of unavailability or cost including the effect of the aging of the components and models of imperfect maintenance. The results obtained in the case of application, which focuses on a system of safety of a nuclear power station, show differences, mainly in the outage when you consider the aging. (Author)
[en] There is a growing interest from both the regulatory authorities and the nuclear industry to stimulate the use of Probabilistic Risk Analysis (PRA) for risk-informed applications at Nuclear Power Plants (NPPs). Nowadays, special attention is being paid on analyzing plant-specific changes to Test Intervals (TIs) within the Technical Specifications (TSs) of NPPs and it seems to be a consensus on the need of making these requirements more risk-effective and less costly. Resource versus risk-control effectiveness principles formally enters in optimization problems. This paper presents an approach for using the PRA models in conducting the constrained optimization of TIs based on a steady-state genetic algorithm (SSGA) where the cost or the burden is to be minimized while the risk or performance is constrained to be at a given level, or vice versa. The paper encompasses first with the problem formulation, where the objective function and constraints that apply in the constrained optimization of TIs based on risk and cost models at system level are derived. Next, the foundation of the optimizer is given, which is derived by customizing a SSGA in order to allow optimizing TIs under constraints. Also, a case study is performed using this approach, which shows the benefits of adopting both PRA models and genetic algorithms, in particular for the constrained optimization of TIs, although it is also expected a great benefit of using this approach to solve other engineering optimization problems. However, care must be taken in using genetic algorithms in constrained optimization problems as it is concluded in this paper
[en] This paper presents the optimization of the testing surveillance and maintenance (TS and M) plan for high-pressure injection system (HPIS) in a nuclear power plant. Using the Particle Swarm Optimization (PSO) is obtained a group of viable solutions, each one corresponding to a non-dominated solution, which can be implemented in the plant.
[en] In a setting of stop with discovery of kernel crash is of special interest the maximum temperature of fuel elements (PCT) pod. The difficulty to directly measure this temperature makes is look for the measurement of the temperature of exit of the nucleus (CET). This paper proposes to study the correlation between these basic parameters of measurement in a commercial plant, based on the results of the simulation of different cases through the Thermo-hydraulic TRACE code.
[en] The applicability of the results of the experimental facility and its implications from the point of view of security of the same. have been studied Likewise within the experiment possible corrective measures for implementation to keep the plant in stable situation against the accidental happening.
[en] We study the recently introduced random walk problems of partial covering time (PCT) and random covering time (RCT). We generalize the concept of first-passage time to a given set of m sites by considering the probability of visiting all m sites for the first time on the tth step. For the one-dimensional case we derive an explicit result for the mean time needed to visit m sites for the first time. Using this result we are able to solve the PCT and RCT problems exactly in one dimension
[en] The purpose of this document focuses on the use of analysis of importance in the proposed approach. It provides a case study that focuses on a AOT change of the accumulators system of an Nuclear power plant with an APS of level 1