The performance of diagnostic systems based on empirical models may vary in different zones of the training space. It is, thus, important to a-priori verify whether the model is working in a zone where the performance is expected to be satisfactory. In this respect, the objective of this work is to estimate the degree of confidence in the identification of nuclear transients by a diagnostic sys...

Liquid metals such as Bi and Pb and Pb–Bi eutectic alloy are serious contenders for use as coolant in LMFBRs in lieu of sodium due to a number of attractive characteristics (high density, low moderation, low neutron absorption and activation, high boiling point and poor interaction with water and air, etc.). Analysis of hypothetical accidents is of relevance to predict the catastrophe involving...

This paper presents a Fault Detection and Isolation (FDI) system that can detect and isolate nuclear power plant (NPP) faults occurring in interacting systems. The proposed methodology combines two tools: observer based residual generation and neural network pattern matching into a powerful, hybrid diagnostic system. A computer-based model of a commercial Boiling Water Reactor (BWR) is used as ...

Recent advances in computational fluid dynamics (CFD) codes along with high performance computing hardware made the codes more useful in many engineering applications. For instance, single-phase CFD codes have long been used to predict the fluid flow in fuel channels of a pressurized water reactor (PWR) [1, 2]. Considering the current affordable number of computation mesh is a little below one ...

In Indonesia, where diarrhea remains a major cause of mortality among children <5 years, the government promotes boiling of drinking water. We assessed the impact of boiling on water quality in South Sulawesi. We surveyed randomly selected households with at least one child <5 years old in two rural districts and tested source and stored water samples for Escherichia coli contamination. Among 2...

The authors examined the demand for clean drinking water using treatment behaviors in Kathmandu, Nepal. Water supply is inadequate, unreliable and low quality. Households engage in several strategies to cope with the unreliable and poor quality of water supplies. Some of the major coping strategies are hauling, storing, and point-of-use treatment. Boiling, filtering, and use of Uro-guard are so...

Despite shortcomings, boiling is the most common means of treating water at home and the benchmark against which emerging point-of-use water treatment approaches are measured. In a 5-month study, we assessed the microbiological effectiveness and cost of the practice among 218 self-reported boilers relying on unprotected water supplies. Boiling was associated with a 99% reduction in geometric me...

Since the introduction of mechanical seals in nuclear boiling water reactor (BWR) feed pumps operating with high drive ratings, keeping mechanical seal reliability high became a challenge. A problem also encountered in fossil feed pump applications using similar electrically low conductive feed water, referred to as Combined Water Treated (CWT) feed water operation. After a short number of oper...

The Fukushima accident sequence The earthquake and the subsequent tsunami that devastated part of Northeast Japan on March 11th, 2011, led to a series of accidents in the Fukushima Daichi nuclear plant, constructed and operated by Tokyo Electric Power Company (TEPCO). Only three of the six units of the plant (all of them boiling water reactors, BWR) were operating at that time. The sequence of ...

Sir,?Dr. A. Mitra, of Kashmir, wrote recommending the boiling of water in 1888, but Sir Joseph Fayrer anil Dr. (now Sir) Joseph Ewart wrote the same thing at least four years before, vi le "The book of Health," published by Cassell & Co., Ld., 3rd Edition, page 927, paragraph on the purification of drinking water. The article contributed by those eminent men is headed, " Health in India." The b...