This document discusses systems thinking and ergonomics from a lecture by Professor Alan Hedge. It defines key concepts of systems such as inputs/outputs, open vs closed loop systems, and characteristics of components. The document uses the Three Mile Island nuclear accident as an extensive case study to illustrate issues in human-machine systems and factors that can lead to failures if human aspects are not properly considered.
Human always tries for better comfort and sophistic ation at each level of his life. Considering air conditioning,evaporative cooler is used in dry cli mates. But such evaporative coolers are not suitabl e in humid environment and also their performance is poo r in the places where ventilation is not proper. Re ason behind this is nothing but,uncontrollable humidity increment in the working environment (cabin) due t o process of evaporation. Report is sequential detail s about research carried out on the evaporative coo ler in order to remove this disadvantage. The important pa rameter in whole report is nothing but relative hum idity which should be maintained in specific range for ge tting better thermal comfort. Report briefly explai ns the basic concept required to understand evaporative co oling and performance of evaporative cooling. It al so explains why evaporative cooler is not as effective as air conditioners.
Human always tries for better comfort and sophistic ation at each level of his life. Considering air conditioning,evaporative cooler is used in dry cli mates. But such evaporative coolers are not suitabl e in humid environment and also their performance is poo r in the places where ventilation is not proper. Re ason behind this is nothing but,uncontrollable humidity increment in the working environment (cabin) due t o process of evaporation. Report is sequential detail s about research carried out on the evaporative coo ler in order to remove this disadvantage. The important pa rameter in whole report is nothing but relative hum idity which should be maintained in specific range for ge tting better thermal comfort. Report briefly explai ns the basic concept required to understand evaporative co oling and performance of evaporative cooling. It al so explains why evaporative cooler is not as effective as air conditioners.
For many countries, nuclear power remains an
important option for improving energy security and
reducing the impact of volatile fossil-fuel prices. As
a stable, base-load source of electricity in an era of
ever-increasing global energy demand, nuclear power
complements other energy sources—including renewables.
And because nuclear power, together with hydropower
and wind energy, has the lowest life cycle greenhouse
gas emissions among all power generation sources, it is
crucially linked to mitigating the effects of climate change.
A clear correlation links energy poverty and real
poverty. Energy is the engine of development. In his
vision for Sustainable Energy for All, UN Secretary
General Ban Ki-moon says that “all energy sources and
technologies have roles to play in achieving universal
access in an economically, socially and environmentally
sustainable fashion.” Simply put, to provide energy
access to everyone, all forms of energy are needed.
More information : http://www.sfen.org/
Ocean Thermal Energy Conversion (OTEC) is a marine renewable energy technology that converts solar radiation to electrical power by the temperature difference between the deep cold ocean water and warm tropical surface water.
what steps can be taken to prevent a core melt down when the tur.pdfARORACOCKERY2111
what steps can be taken to prevent a core melt down when the turbine housing ruptures at a
power plant
what steps can be taken to prevent a core melt down when the turbine housing ruptures at a
power plant
what steps can be taken to prevent a core melt down when the turbine housing ruptures at a
power plant
Solution
The prevention of a core melt down begins in the design stage of a nuclear power plant.
Step 1 is the threat assessment for where the reactor is going to be operated. Seismic stability,
tsunami, weather, and available water and power supplies are all evaluated and a probability of a
destructive event during the plant\'s lifetime are all considered. Evey attempt is made to make
these predictions as accurate as possible, but as Fukushima has shown, Mother Nature really is a
mother, and can trump your models in a heartbeat.
So the engineers take the data they get, give it the best look they can, add in some prudent
\"fudge factors\" and design to that.
Fukushima showed that the engineers who do this are a very pessimistic lot. The earthquake that
tore up the region did not damage the plants. It was the tsunami, far larger than predicted, that
did in the plants.
There are two systems or loops, primary and secondary. The primary loop is the water that
circulates through the core. The secondary loop is the steam/condensate loop the turns the
turbine. The primary loop is the one we are concerned with here.
The Step 2 is materials. Nothing goes into the build of the plant without rigorous (some have
said insane) quality control checks. Every part of the primary loop, the base metal, the piping, the
nuts and bolts, have their entire history tracked. And I mean the entire history, from where the
metal came out of the ground to the last delivery on the parts shelf.
Step 3 is the design. The design incorporates multiple, redundant methods to keep the core
cooled.
So the normal method of cooling the core is to circulate water by means of reactor coolant
pumps. (each piping system, consisting of the pump and steam generator and piping is called a
loop) But what if a pump failed, or there is a leak in the piping?
The answer is (at a minimum) there must be a second loop, identical to the first, just in case.
Some designs have 3 or four loops. This is the normal operating condition, where the steam plant
is the heat sink.
But what if the steam plant cannot function? A completely independent system, the Emergency
Core Cooling system, is designed to take over the job if needed.
But what if that fails? Then there is a design for injecting water directly into the core, using
portable pumps (fire trucks) to cool the core.
All these designs, plans, and procedures must be drawn, written up, reviewed and accepted by
the builder, the customer, and the regulators, before the first part is put together
Step 4 are the people who build, install and operate the plant. Every one of them are trained,
tested, retrained, qualified and requalified, to insure they kn.