Integrated Functional Modeling Method for Configuring NPP Plant DiD Risk Monitor and its Application for AP1000

2014 ◽  
Author(s):  
Hidekazu Yoshikawa ◽  
Ming Yang ◽  
Morten Lind ◽  
Takeshi Matsuoka
Keyword(s):  
Plant Defense ◽  
Severe Accident ◽  
Monitor System ◽  
Functional Modeling ◽  
Passive Safety System ◽  
Preliminary Study ◽  
Defense In Depth ◽  
Risk Monitor ◽  
Term Management

A new risk monitor system has been under developing, in order not only to prevent severe accident in daily operation but also even to serve as to mitigate the radiological hazard just after severe accident happens and long term management of post-severe accident consequences. In the proposed risk monitor, the range of risk is not limited to core melt accidents but includes all kinds of negative outcome events, i.e., not only precursor troubles and incident but also any types of hazard states resulting from a severe accident. The whole system of the proposed risk monitor system is configured the by plant Defense-in Depth (DiD) risk monitor and reliability monitor, and in this paper the result of how to configure the Plant Defense in-Depth Risk Monitor by functional modeling approach is first presented. Then, a preliminary study is conducted on applying the integrated functional modeling for Plant Defense-in-depth risk monitor for passive safety system of AP1000.

Reliability Monitor for PWR Safety System Using FMEA and Go-Flow Methodology: Application of Risk Monitor for Nuclear Power Plants

2013 ◽  
Author(s):  
Muhammad Hashim ◽  
Hidekazu Yoshikawa ◽  
Takeshi Matsuoka ◽  
Ming Yang
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Fault Tree Analysis ◽  
Reliability Evaluation ◽  
Safety System ◽  
Severe Accident ◽  
Monitor System ◽  
Dynamic Reliability ◽  
Defense In Depth ◽  
Risk Monitor

Author’s proposed risk monitor system of Nuclear Power Plant (NPP) is based on the idea of Plant Defense-in-Depth (DiD) risk monitor and reliability monitor to monitor what degree of safety functions incorporated in the plant system is maintained by multiple barriers of Defense-in-Depth (DiD). In the risk monitor system, the range of risk state is not limited in core damage accident but includes all kinds of dangerous states brought by severe accident. In present study, method of the reliability monitor of a risk monitor system is applied to the PWR safety system in order to evaluate the risk state numerically by pursuing all conditions of reliability evaluation given by plant DiD risk monitor. Large break LOCA is taken as an initiating accident event and the implementation of method of the reliability monitor is discussed in detail for single loop PWR safety system by considering the Multilevel Flow Model (MFM), Failure Mode and Effect Analysis (FMEA), and the qualitative reliability evaluation by Fault Tree Analysis (FTA) and the dynamic reliability evaluation by GO-FLOW. The summary of reliability results of PWR safety subsystems are also presented.

A preliminary study of regeneration in wild populations of threatened endemic Hawaiian palms (Pritchardia; Arecaceae)

2007 ◽  
Vol 13 (1) ◽  
pp. 20 ◽  
Author(s):  
Melany H. Chapin ◽  
Mike Maunder ◽  
Katherine E. Horak
Keyword(s):  
Seed Predation ◽  
Conservation Management ◽  
Management Strategies ◽  
Ecological Change ◽  
Wild Populations ◽  
In The Wild ◽  
Human Colonization ◽  
Preliminary Study ◽  
Term Management

Island floras have been subject to catastrophic changes since human colonization; the Hawaiian Islands exemplify this pattern of species decline and ecological change. Archaeological and historic findings support the former existence of coastal, lowland and interior Pritchardia dominated forests. Wild Pritchardia populations are highly fragmented and exhibit poor or absent regeneration in the wild. This study records seed predation, goat grazing, pig damage, and human harvesting on six wild populations of three species and outlines requirements for the long-term management of wild populations. Only one population of the six studied was found to contain seedlings. Recommended conservation management strategies are outlined.

Knowledge-based software design for Defense-in-Depth risk monitor system and application for AP1000

2017 ◽  
Vol 54 (5) ◽  
pp. 552-568 ◽  
Author(s):  
Zhanguo Ma ◽  
Hidekazu Yoshikawa ◽  
Takashi Nakagawa ◽  
Ming Yang
Keyword(s):  
Software Design ◽  
Monitor System ◽  
Knowledge Based ◽  
Defense In Depth ◽  
Risk Monitor

Effects of surgical technique on bone. A preliminary study

1994 ◽  
Vol 84 (3) ◽  
pp. 115-119
Author(s):  
JD Johnson ◽  
HK Jones ◽  
DP Feigelson ◽  
J Gerbert ◽  
A Pedroja
Keyword(s):  
Surgical Technique ◽  
Treatment Effect ◽  
Surgical Patient ◽  
Significant Digit ◽  
Distal Interphalangeal ◽  
Preliminary Study ◽  
Term Management ◽  
Slight Advantage

The authors compared the use of the power saw with bone-cutting forceps for excision of bone. A total of 44 digits were studied in 12 patients. The study was performed on patients requiring bilateral digital arthroplasties of the proximal and distal interphalangeal joints. The authors examined the differences in healing: pain, inflammation, and fibrosis. Digits on which the power cuts were made showed a slight advantage with regard to inflammation and pain, until 1 week after surgery. By week 12, neither technique demonstrated superiority. Overall results demonstrated no significant digit (p > 0.2) or treatment effect (p = 0.11). The authors believe that the study showed that the technique used for bone excision may have little effect on inflammation and healing in the long-term management of a surgical patient.

scholarly journals CFD Analysis of a Decay Tank and a Siphon Breaker for an Innovative Integrated Passive Safety System for a Research Reactor

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Kwon-Yeong Lee ◽  
Hyun-Gi Yoon ◽  
Dong Kyou Park
Keyword(s):  
Research Reactor ◽  
Safety System ◽  
Integrated System ◽  
Severe Accident ◽  
Passive Safety ◽  
Tank Model ◽  
Passive Safety System ◽  
Computational Fluid Dynamics Analysis ◽  
New Type

An innovative integrated passive safety system for a research reactor is proposed in this study to improve the safety of the research reactor. This integrated system has three functions in the facility as a decay tank, siphon breaker, and long-term cooling tank. This paper also deals with the process of designing and optimizing the decay tank and the siphon breaker of the integrated passive safety system. At first, the decay tank was designed and improved step by step, while considering the computational fluid dynamics analysis results. Consequently, we could satisfy the design requirements of the decay tank. In addition, the performance of a new type of siphon breaker that was installed in the final decay tank model was tested. We designed an 18-inch diameter siphon breaker at the top of the decay tank’s third section, and we could observe the breaking of the siphon that prevented the occurrence of a severe accident in the research reactor. By locating the siphon breaker at the third section of the decay tank, we could also use the coolant of the front three sections for long-term cooling of the research reactor.

Ultrastructural observations of the aorta of calves implanted with a mechanical left ventricular assist device

1990 ◽  
Vol 48 (3) ◽  
pp. 834-835
Author(s):  
J P Cassella ◽  
V Salih ◽  
T R Graham
Keyword(s):  
Left Ventricular Assist Device ◽  
Ventricular Assist Device ◽  
Left Ventricular ◽  
Aortic Tissue ◽  
Assist Device ◽  
Ventricular Assist ◽  
Transmission Electron ◽  
Left Ventricular Assist ◽  
Preliminary Study

Left ventricular assist systems are being developed for eventual long term or permanent implantation as an alternative to heart transplantation in patients unsuitable for or denied the transplant option. Evaluation of the effects of these devices upon normal physiology is required. A preliminary study was conducted to evaluate the morphology of aortic tissue from calves implanted with a pneumatic Left Ventricular Assist device-LVAD. Two 3 month old heifer calves (calf 1 and calf 2) were electively explanted after 128 days and 47 days respectively. Descending thoracic aortic tissue from both animals was removed immediately post mortem and placed into karnovsky’s fixative. The tissue was subsequently processed for transmission electron microscopy (TEM). Some aortic tissue was fixed in neutral buffered formalin and processed for routine light microscopy.

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