Planta nuclear de Fukushima: pérdida de agua radiactiva

20 August 2013 Last updated at 10:57 GMT

Fukushima nuclear plant: Radioactive water leak found

The tsunami knocked out cooling systems to the reactors at Fukushima

Radioactive water has leaked from a storage tank into the ground at Japan's Fukushima plant, its operator says.

Tokyo Electric Power Company (Tepco) said the leak of at least 300 tonnes of the highly radioactive water was discovered on Monday.

The plant, crippled by the earthquake and tsunami in 2011, has seen a series of water leaks and power failures.

The tsunami knocked out cooling systems to the reactors, three of which melted down.

An employee discovered the leak on Monday morning, Tepco said in a statement.

Officials described the leak as a level-one incident - the lowest level - on the International Nuclear and Radiological Event Scale (Ines), which measures nuclear events.

This is the first time that Japan has declared such an event since the 2011 earthquake and tsunami, however.

Under the Ines, events have seven categories starting with Level 0 ("without safety significance") and Levels 1-3 denoting "incidents" while Levels 4-7 denote "accidents".

A puddle of the contaminated water was emitting 100 millisieverts an hour of radiation, Kyodo news agency said.

Masayuki Ono, general manager of Tepco, told Reuters news agency: "One hundred millisieverts per hour is equivalent to the limit for accumulated exposure over five years for nuclear workers; so it can be said that we found a radiation level strong enough to give someone a five-year dose of radiation within one hour."

More monitoring

A Tepco official told a press conference on Tuesday that the water probably leaked from a tank after escaping a concrete barrier.

Workers were pumping out the puddle and the remaining water in the tank and would be transferring it to other containers, Kyodo added.

Water is being pumped into the reactors after cooling systems were knocked out by the tsunami.

Hundreds of tanks were built to store the contaminated water. Some of them had experienced similar leaks since 2012, but not on this scale, a Tepco official said.

Tepco had been instructed to retrieve contaminated soil and to strengthen monitoring of the surrounding environment, a regulatory official told Agence-France Presse news agency.

No major changes in radiation levels outside the plant had been observed so far, the official added.

The incident comes days after Tepco admitted that as much as 300 tonnes of contaminated water a day was leaking from the damaged reactor buildings to the sea.

http://www.bbc.co.uk/news/world-asia-23764382

Organizador gráfico sobre agua radiactiva en Fukushima

KNOW	WANT TO KNOW	LEARNED
- En 2011 un terremoto, y posterior tsunami, provocó la ruptura de los reactores causando la segunda pero catástrofe radiactiva después de Chernobyl. - Se encontró agua radiactiva afuera de la planta de Fukushima. Se está investigando el origen.	- ¿Qué tiene el agua radiactiva? - ¿Cuál es la situación actual de la planta? - ¿Qué perjuicios puede tener para las personas que estuvieron en contacto con el agua radiactiva?	- Fueron descubiertas pérdidas de 300 toneladas de agua radiactiva. - La pérdida fue catalogada como “incidente”. El nivel más bajo en la escala de eventos nucleares y radiactivos. - Un charco de agua contaminada emitió 100 milisieverts de radiación en una hora. 100 milisieverts por hora equivale al límite de exposición acumulada por 5 años de un trabajador nuclear. - Un funcionario de Tepco dijo en una conferencia que el agua provenía probablemente del escape de una barrera de hormigón. - Cientos de tanques fueron construidos para contener el agua contaminada. Algunos han tenido pérdidas desde 2012 pero no a esta escala. - El incidente ocurrió días después que Tepco admitió que 300 toneladas de agua contaminada al día son vertidos al océano desde los reactores dañados. - Tepco dice que esta es la pero fuga en volumen y en términos radiactivos. Supera 80 millones de veces el límite permitido de bequereles por litro en agua potable. - La preocupación es que esta agua sea vertida dentro del mar que está a 100 metros de distancia.

Agua radiactiva en la costa de Fukushima

Texto 1 Conectivismo

                                        http://www.connectivism.ca/about.html

Connectivism is a learning theory for the digital age. Learning has changed over the last several decades. The theories of behaviourism, cognitivism, and constructivism provide an effect view of learning in many environments. They fall short, however, when learning moves into informal, networked, technology-enabled arena. Some principles of connectivism:

§  The integration of cognition and emotions in meaning-making is important. Thinking and emotions influence each other. A theory of learning that only considers one dimension excludes a large part of how learning happens.

§  Learning has an end goal - namely the increased ability to "do something". This increased competence might be in a practical sense (i.e. developing the ability to use a new software tool or learning how to skate) or in the ability to function more effectively in a knowledge era (self-awareness, personal information management, etc.). The "whole of learning" is not only gaining skill and understanding - actuation is a needed element. Principles of motivation and rapid decision making often determine whether or not a learner will actuate known principles.

§  Learning is a process of connecting specialized nodes or information sources. A learner can exponentially improve their own learning by plugging into an existing network.

§  Learning may reside in non-human appliances. Learning (in the sense that something is known, but not necessarily actuated) can rest in a community, a network, or a database.

§  The capacity to know more is more critical that what is currently known. Knowing where to find information is more important than knowing information.

§  Nurturing and maintaining connections is needed to facilitate learning. Connection making provides far greater returns on effort than simply seeking to understand a single concept.

Learning and knowledge rest in diversity of opinions.

Learning happens in many different ways. Courses, email, communities, conversations, web search, email lists, reading blogs, etc. Courses are not the primary conduit for learning.

Different approaches and personal skills are needed to learn effectively in today's society. For example, the ability to see connections between fields, ideas, and concepts is a core skill.

Organizational and personal learning are integrated tasks. Personal knowledge is comprised of a network, which feeds into organizations and institutions, which in turn feed back into the network and continue to provide learning for the individual. Connectivism attempts to provide an understanding of how both learners and organizations learn.

Currency (accurate, up-to-date knowledge) is the intent of all connectivist learning.

Decision-making is itself a learning process. Choosing what to learn and the meaning of incoming information is seen through the lens of shifting reality. While there is a right answer now, it may be wrong tomorrow due to alterations in the information climate impacting the decision.

Learning is a knowledge creation process...not only knowledge consumption. Learning tools and design methodologies should seek to capitalize on this trait of learning.

Texto 2 Conectivismo

26

Theories for the digital age: Connectivism

Learning in the industrialised world can now be contextualised within a largely technological landscape, where the use of digital media is assuming increasing importance.  Much of this learning is informal, (Commentators such as Cofer (2000), Cross (2006) and Dobbs (2000) place the proportion of informal learning at around 70%) and is also generally location independent.

The present technology rich learning environment is characterised by a sustained use of digital media, their integration into formal contexts, and a shift toward personalisation of learning. These facets of modern life in combination have led educators to question the validity of pre-digital age learning theories. In recent years a range of new explanatory theories has been generated that can be applied as lenses to critically view, analyse and problematise new and emerging forms of learning. 

One highly visible theory is Connectivism (Siemens, 2004). Connectivism has been lauded as a ‘learning theory for the digital age’, and as such seeks to describe how students who use personalised, online and collaborative tools learn in different ways to previous generations of students. The essence of Siemens’ argument is that today, learning is lifelong, largely informal, and that previous human-led pedagogical roles and processes can be off-loaded onto technology. Siemens also criticises the three dominant learning theories, namely behaviourism, cognitivism, and constructivism, suggesting that they all locate learning inside the learner. His counterargument is that through the use of networked technologies, learning can now be distributed outside the learner, within personal learning communities and across social networks.

Perhaps the most significant contribution of Connectivist theory is the premise that declarative knowledge is now supplemented or even supplanted by knowing where knowledge can be found. In a nutshell, connectivism argues that digital media have caused knowledge to be more distributed than ever, and it is now more important for students to know where to find knowledge they require, than it is for them to internalise it. This places the onus firmly upon each student to develop their own personalised learning tools, environments, learning networks and communities within which they can ‘store their knowledge’ (Siemens, 2004). In McLuhan’s view, as we embrace technology, ‘our central nervous system is technologically extended to involve us in the whole of mankind and to incorporate the whole of mankind in us’ (McLuhan, 1964, p. 4). Clearly our social and cultural worlds are influenced by new technology, but are there also biological implications?

References

Cross, J. (2006) Informal Learning: Rediscovering the natural pathways that inspire innovation and performance.London: John Wiley and Sons. 

Cofer, D. (2000) Informal Workplace Learning. Practice Application Brief No. 10, U.S. Department of Education: Clearinghouse on Adult, Career, and Vocational Education.

Dobbs, K. (2000) Simple Moments of Learning. Training, 35 (1), 52-58.

McLuhan, M. (1964) Understanding Media. London: McGraw Hill.
Siemens, G. (2004) Connectivism: A LearningTheory for the Digital Age. eLearnspace. 

 

 

http://steve-wheeler.blogspot.com/2012/10/theories-for-digital-age-connectivism.html

Cuadro comparativo

 

Cuadro comparativo entre el texto trabajado en clase

y el encontrado en la web

 

Texto 1	Texto 2
El conectivismo es una teoría de aprendizaje para la era digital.	El conectivismo es una teoría de aprendizaje para la era digital y describe cómo los estudiantes utilizan las herramientas en línea para aprender de diferente manera que las generaciones anteriores.
Las demás teorías de aprendizaje (conductivismo, cognitivismo y constructivismo) dejan de lado la era tecnológica o digital y el cómo se aprende en ella.	Las demás teorías de aprendizaje (conductivismo, cognitivismo y constructivismo) sostienen que el aprendizaje se localiza en el interior del alumno. Sin embargo, el conectivismo afirma que con el uso de las tecnologías de red el aprendizaje puede ser distribuido fuera del alumno.
-          Para el conectivismo los pensamientos y emociones de cada uno influyen en la elaboración de significados. -          El aprendizaje tiene como objetivo incrementar la habilidad para hacer algo. -          El aprendizaje es un proceso de conexión de nodos especializados con fuentes de información. -          El aprendizaje ocurre en artefactos no humanos. -          La capacidad de saber más es más importante que el conocimiento actual. -          Nutrición y mantenimiento de conexiones es necesario para facilitar el aprendizaje.	-          El conectivismo se basa en la idea de que los medio digitales han distribuido el conocimiento más que nunca. -          Que los estudiantes sepan dónde encontrar el conocimiento que buscan es más importante que  internalizarlo.