This text presents a block diagram proposal of protection system for a PWR nuclear power plant. It describes the plant operation, as well as it defines what a protection system is. Some of the main inherent definitions to protection systems are shown and the system operation is explained in a global form. The block diagram proposed for the protection system can be used as a project foundation f...

加圧水型軽水炉(PWR)では，燃料集合体から蒸気発生器(SG)伝熱管に至るまで，随所にNi基合金が用いられており，PWRの安全性，信頼性評価を行う上で，これらのNi基合金の高経年化に伴う環境助長割れ特性評価は極めて重要である。特にSG伝熱管材の粒界損傷(IGA)や，一次系水中でのNi基合金の応力腐食割れ(PWSCC)は，PWRの稼働率を下げる要因の一つになった事から関係者に与えた衝撃は大きかった。そこで本稿では，先ず今までに経験したPWR用Ni基合金の環境助長割れについて，内外の今迄の研究・開発動向等を踏まえ論評する。

It is generally recognized that the spent fuel discharged from nuclear power plants constitutes the main contribution to nuclear waste. The management of spent fuel from nuclear power plants differs depending on the perspectives and scenarios posed by the countries directly concerned. However, there is a general consensus on the need for a deep geological repository and a reduction in the burde...

A new approach to PWR simplification is presented, in which a compact Reactor Coolant System (RCS) configuration introduced, particularly suited for power level the range of 600 MWe. Customary primary system components are eliminated achieve this RCS simplification. For example, pressure control through “self-pressurization” mode, with core exit at saturation temperature less than 1% steam, all...

Myocardial depression in sepsis is frequently encountered clinically and contributes to morbidity and mortality. Increased plasma levels of endothelin-1 (ET-1) have been described in septic shock, and previous reports have shown beneficial effects on cardiovascular performance and survival in septic models using ET receptor antagonists. The aim of the current study was to investigate specific c...

This paper presents MFM builder, a platform based on Multilevel Flow Modeling (MFM), which provides a graphical interface for modeling functions of complex artificial systems such as nuclear power plant with emphasizing the designed purposes of systems. Several algorithms based on MFM have been developed for dynamic system reliability analysis, fault diagnosis and quantitative software reliabil...

Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by volume). Since CHF is the upper limit of nucleate boiling, such enhancement offers the potential for major performance improvement in many practical applications that use nucleat...

The article considers the existing models and correlations for describing heat transfer during film boiling. Film boiling is an important thermophysical process that determines course of interaction melt reactor core materials with coolant, which can potentially occur a severe accident at nuclear power plant pressurized water-cooled (VVER/PWR). values Nusselt number predicted by these are compa...