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Incursions of southern-sourced water into the deep North Atlantic during late Pliocene glacial intensification

Nature Geoscience Advanced Online - Sun, 04/03/2016 - 23:00

Nature Geoscience. doi:10.1038/ngeo2688

Authors: David C. Lang, Ian Bailey, Paul A. Wilson, Thomas B. Chalk, Gavin L. Foster & Marcus Gutjahr

The circulation and internal structure of the oceans exert a strong influence on Earth’s climate because they control latitudinal heat transport and the segregation of carbon between the atmosphere and the abyss. Circulation change, particularly in the Atlantic Ocean, is widely suggested to have been instrumental in the intensification of Northern Hemisphere glaciation when large ice sheets first developed on North America and Eurasia during the late Pliocene, approximately 2.7 million years ago. Yet the mechanistic link and cause/effect relationship between ocean circulation and glaciation are debated. Here we present new records of North Atlantic Ocean structure using the carbon and neodymium isotopic composition of marine sediments recording deep water for both the Last Glacial to Holocene (35–5 thousand years ago) and the late Pliocene to earliest Pleistocene (3.3–2.4 million years ago). Our data show no secular change. Instead we document major southern-sourced water incursions into the deep North Atlantic during prominent glacials from 2.7 million years ago. Our results suggest that Atlantic circulation acts as a positive feedback rather than as an underlying cause of late Pliocene Northern Hemisphere glaciation. We propose that, once surface Southern Ocean stratification and/or extensive sea-ice cover was established, cold-stage expansions of southern-sourced water such as those documented here enhanced carbon dioxide storage in the deep ocean, helping to increase the amplitude of glacial cycles.

Melting at the base of the Greenland ice sheet explained by Iceland hotspot history

Nature Geoscience Advanced Online - Sun, 04/03/2016 - 23:00

Nature Geoscience. doi:10.1038/ngeo2689

Authors: Irina Rogozhina, Alexey G. Petrunin, Alan P. M. Vaughan, Bernhard Steinberger, Jesse V. Johnson, Mikhail K. Kaban, Reinhard Calov, Florian Rickers, Maik Thomas & Ivan Koulakov

Ice-penetrating radar and ice core drilling have shown that large parts of the north-central Greenland ice sheet are melting from below. It has been argued that basal ice melt is due to the anomalously high geothermal flux that has also influenced the development of the longest ice stream in Greenland. Here we estimate the geothermal flux beneath the Greenland ice sheet and identify a 1,200-km-long and 400-km-wide geothermal anomaly beneath the thick ice cover. We suggest that this anomaly explains the observed melting of the ice sheet’s base, which drives the vigorous subglacial hydrology and controls the position of the head of the enigmatic 750-km-long northeastern Greenland ice stream. Our combined analysis of independent seismic, gravity and tectonic data implies that the geothermal anomaly, which crosses Greenland from west to east, was formed by Greenland’s passage over the Iceland mantle plume between roughly 80 and 35 million years ago. We conclude that the complexity of the present-day subglacial hydrology and dynamic features of the north-central Greenland ice sheet originated in tectonic events that pre-date the onset of glaciation in Greenland by many tens of millions of years.

18 years – 10 months! The Global Warming ‘Pause’ refuses to go away, despite greatly exaggerated rumors of its death

Climate Depot - Sun, 04/03/2016 - 16:25
Special to Climate Depot Via: https://kenskingdom.wordpress.com/2016/04/02/the-pause-update-march-2016-preliminary/ The Pause Update: March 2016 (Preliminary) Well my last post certainly stirred up some Global Warming Enthusiasts who found it difficult to get their heads around the continued existence of The Pause.  What will they make of this month’s update?  The Pause refuses to go away, despite greatly exaggerated rumours of [...]

‘Never before seen’ spring snowfall in the Caribbean islands – & Colorado Ski Resort snowiest in 50 years – Snow chaos in Germany

Climate Depot - Sun, 04/03/2016 - 15:37
Via: http://iceagenow.info/ ‘Never before seen’ spring snowfall in the Caribbean islands (Update: This article from the Dominca News Online was an April Fool’s joke. See: UPDATE: It Did Not Snow in Guadeloupe) APRIL 3, 2016 – “No, it is not an April Fools Day joke, snowflakes actually fell in the neighbouring French island of Guadeloupe.” PHOTO: ‘Residents film the falling [...]

Attorneys General Create Axis For Global Warming Shakedown

Climate Depot - Sat, 04/02/2016 - 20:51
http://www.investors.com/politics/editorials/attorneys-general-create-axis-for-global-warming-shakedown/ Inquisition: The top law enforcement officers in 16 states have formed a coalition to investigate and prosecute companies that don’t agree with them on climate change. In other words, those not practicing orthodoxy will be punished. Joining this distinguished group of modern-day Torquemadas at its formation was Al Gore, who apparently has nothing better [...]

Retooling the Workforce for Small Modular Reactors

This Week In Nuclear - Wed, 12/25/2013 - 14:22

Smaller reactors have many advantages, but in order to be cost effective in competitive energy markets a typical small modular reactor (SMR) will need to operate with a much smaller workforce than today’s large commercial nuclear energy facilities.  This will mandate a retooling of existing nuclear training programs to align with the knowledge and skills needed by the SMR staff.

As opposed to fossil-fueled power plants in which the majority of operating costs are associated with the fuel they burn, the majority of the costs of generating electricity from nuclear energy are associated with the costs of capital to build the plant, and the ongoing cost of people needed to operate and maintain (O&M) the plant.  The capital costs, determined by construction & financing costs, are generally fixed during the first decades of operation.  The O&M costs, however, vary over the life of the plant and are highly dependent on overall labor costs; the number of people required and their salaries and benefits, contracted labor costs, and the cost of out-sourced services. For this reason the long-term economic viability of nuclear energy facilities relies upon maintaining capacity factors high and labor costs reasonable and predictable.  Obviously, the balance sheet also depends on the structure of the energy market in which the facility is located.

Anti-nuclear groups understand this connection between labor costs and economic viability.  For years their strategy has been to convince nuclear regulators of the need for ever-tougher standards resulting in larger and larger staff sizes and thus tighter profit margins.  They are, in a very deliberate way, working to regulate nuclear energy out of business.  Coupled with lower electricity market prices brought about by falling natural gas prices, these higher labor costs mean some smaller nuclear plants are finding it increasingly difficult to maintain profitability. Utilities planning to deploy SMRs can expect these same anti-nuclear groups to push for regulations to limit their ability to operate with the smaller staff sizes needed.

Using “ball park” numbers, today’s large 1000 MWe nuclear plants typically employ a staff of about 700 people, or about 0.7 people per megawatt. At this ratio a 100 MWe SMR would employ only about 70.  Under today’s paradigm of division of labor within a nuclear plant, separate groups of specialized workers perform various functions; operators operate the plant, maintenance technicians maintain and repair the equipment, chemists monitor and control the chemistry within plant systems, planners and schedulers do the planning and scheduling, and radiation protection technicians monitor radiation levels and help ensure everyone works safely.  The staff size enables economies of scale; in this case specialization is efficient because the amount of work being performed is more than enough to fully engage each specialized group. In recent years most nuclear plants have deployed cross functional “Fix-it-Now” or FIN teams made up of one or two people from each specialty. The FIN Teams are highly efficient at performing a routine or less complex maintenance tasks that require multiple skill sets.

The smaller, simpler physical plant typical of an SMR will mean a lower overall volume of maintenance, and less opportunity to take advantage of the economies of scale afforded by workforce specialization. This translates into the need for a multi-skilled staff in which the same people who operate the plant perform a wide rage of maintenance tasks.  Much like a FIN Team, operators in SMRs will likely plan their own maintenance work, perform their own chemical monitoring and analysis, and provide their own radiation protection coverage.  With broader skill sets required, the training programs for this new breed of SMR operator-technician will need to include greater coverage of operations, maintenance, chemistry, and radiation protection knowledge and skills than do the training programs currently in place for the more specialized operators and technicians at gigawatt scale reactors.

This is not a new concept; the Nuclear Navy has used a multi-skilled operator concept since it’s beginning.  On a submarine every operator also has a maintenance specialty, and when not operating the power plant they perform maintenance on their assigned equipment.  In fact, the specialization that exists in today’s land-based utility-sized nuclear plants came about as a natural evolution of the larger staff sizes needed to maintain the scores of pumps and miles of pipes and wiring that exist in gigawatt scale nuclear plants.  The commercial SMR organization will need to look and function much more like that of another type of SMR, the “small mobile reactor” (or “Small Marine Reactor”).

There are alternatives. For example,

  • Utilities with other generating assets could rely on roving teams of maintenance specialists to perform more complex repairs, limiting the need for the SMR staff to undertake these tasks.  This would work particularly well if an SMR were located near an existing larger commercial reactor.
  • Workers who serve the utility’s coal and gas power plants could be cross-trained to work on the SMRs.
  • Different companies operating the same vintage of SMR could form alliances and create maintenance teams that would travel from reactor to reactor.
  • Utilities operating SMRs could out-source more complex maintenance activities to third-party service providers.

Many of these approaches are already in use at fossil-fueled and renewable generating stations, and at some large utilities that operate mostly non-nuclear power stations, but have one or two nuclear plants. Whichever approaches utilities elect to deploy, it will require retooling the existing nuclear training programs to align with the SMR technologies, workforce strategies, and management philosophies. A step-by-step approach to accomplish this retooling would be:

  1. Establish an over-arching vision of how the SMR will operated and maintained within an “all in” target labor budget.
  2. Create a set of organization design principles that encompass the ideals set forth in the vision. This vision should consider what types of work the station staff will perform, what work will be handled by alliance partners, what will be out-sourced, and when contingent labor would be brought in to fill the gap.
  3. Develop an operating system; essentially a high level description of “who does what” at the SMR. Define roles and responsibilities for each group within and outside of the organization.
  4. Design a model SMR organization that conforms to the design principles and implements the operating system within the established labor budget.
  5. Perform a job and task analysis (JTA) for each category of worker in the SMR organization. The JTA forms the bases for identifying the necessary knowledge, skills, and abilities each training program must impart to participants. This is the first step in the “systematic approach to training” and is the precursor to designing and developing the SMR training programs.
  6. Engage human resources professionals to establish a compensation structure aligned with the model organization, a long rage workforce plan, and a talent sourcing strategy.
  7. These strategies could evolve over time as additional SMR units are added to the site and efficiencies of scale become available.

The specifics of the JTAs will depend among other things on the SMR design, the technologies deployed, the man-machine interface, and the ease of maintenance.  It would be prudent for the engineers involved in the design of the first wave of SMRs to “think like” operators, maintenance technicians, chemists, and radiation protection technicians as they put the finishing touches on their designs and operating license applications.  Without consideration of the knowledge and skills it will take to operate, maintain, and repair the first generation of SMRs, designers risk building machines that cannot be economically operated.


John Wheeler

5 Nuclear Jobs Starting at $50,000 Without a 4-year Degree

This Week In Nuclear - Fri, 12/13/2013 - 03:42

“If I only knew then what I know now!”

I was having a conversation with a friend who had spent years working full time while putting himself through college. His business degree had landed him a good job in the corporate support organization of  a large electric utility.  He was happy to have it and his smarts, maturity, and work ethic had served him well.

Yet to some extent he lamented his choice of a four-year business degree because he saw friends in nuclear technical fields advancing faster and earning more money.  Rather than being graduates of four-year colleges or universities, many had started their careers with an associate degree, military training or a certificate in a skilled trade. In many cases this meant they began earning more at an earlier age and had little student loan debt.  If my colleague had been aware of these opportunities he may have chosen a different path. In the least he would  have made an informed decision.

Even in the highly technical field of nuclear energy there are many jobs that do not require a 4-year degree for an entry-level position.  Most of these have starting wages of about $50,000 per year (more if you include overtime and bonuses). In each of these positions there is an established career progression. Pay increases as you complete company-provided training and achieve higher levels of qualification.  I have known many coworkers in these types of jobs who with just two or three years of experience routinely earn more than $100,000 per year with overtime and bonuses.  Even better, these positions are the entry points for supervisory and management positions meaning there is opportunity for long-term career growth.

So what are these great jobs that don’t require a 4-year degree?  Here are some examples:


Radiation Protection Technician (also called health physics technician)

Radiation protection technicians monitor radiation levels throughout the nuclear energy facility. They also maintain and calibrate radiation protection instruments and equipment. They play an important role in helping fellow employees work safely in areas where radiation levels are greater than natural background.

Electrical Technician (also called nuclear electrician)

Electrical technicians install, repair and maintain the highly complex electrical and electronic equipment in the nuclear plant. They work on power plant equipment like motors, circuit breakers, electrical cables, switchgear, generators, transformers, and batteries.

Instrument & Controls Technician

I&C technicians are the “industrial computer technicians” in nuclear energy facilities. They install, test, calibrate, troubleshoot, and repair nuclear plant instrumentation and control equipment and systems.

Mechanical Maintenance Technician (also called nuclear mechanic)

Mechanical maintenance technicians keep all the power plant and reactor mechanical systems and equipment running smoothly and reliably.  They install, test, and repair equipment like pumps, valves, piping systems, heat exchangers, air conditioning, and emergency diesel engines.

 Nuclear Plant Operator (also called non-licensed operator)

Nuclear plant operators start up, monitor, shut down, and test systems and equipment throughout the nuclear energy facility. They also ensure equipment is properly removed from service so that maintenance may be safely performed.  Once work is complete they return the systems to service. The nuclear plant operator position is the first step in becoming a licensed reactor operator or senior reactor operator.


When I speak to young people about careers in the nuclear industry I often suggest they consider an alternative to starting with a four-year degree; instead why not start with an associate degree from a community college leading to one of these positions.  Later you can return to school using the company’s tuition reimbursement program and earn your bachelors degree. This approach is far less costly and gets young people into the workforce sooner with a highly marketable set of skills.

Demand is high in all of these positions.  Each nuclear energy facility employs more than 100 workers in these types of jobs. Today there are 100 nuclear energy facilities in operation in the USA and 435 around the world with another 70 under construction (four are under construction in the USA).  The US Bureau of Labor Statistics projected a 14% increase in the number of nuclear technician jobs between 2010 and 2020.  That number understates the real opportunity because their data does not include hiring needed to replace retiring workers. Over the next several years the need to replace retiring workers means utilities in the United States will be hiring thousands of workers into these positions.  These skills are readily transferable to other industries too (petrochemical, advanced manufacturing, and other energy industry segments).

Links to resources for exploring nuclear career opportunities:
  1. Careers & Education in the Nuclear Industry (from the Nuclear Energy Institute)
  2. Get into Energy, a web site containing information about careers in the broader energy industry.
  3. US Bureau of Labor Statistics
  4. Nuclear Power Reactors in the World, 2013 Edition, International Atomic Energy Agency


This post originally appeared on the Nuclear Workforce Strategies blog

The Global Nuclear Renaissance Rolls On, Career Opportunities Continue

This Week In Nuclear - Wed, 12/11/2013 - 22:10

Despite claims by anti-nuclear groups of the pending demise of nuclear energy production in the United States, the nuclear renaissance is alive and well. According to the non-partisan Energy Information Administration, nuclear energy production in the USA will continue to expand for the next 25 years.

Electricity generation from nuclear power plants grows by 14 percent in the AEO2013 Reference case, from 790 billion kilowatt-hours in 2011 to 903 billion kilowatt-hours in 2040, accounting for about 17 percent of total generation in 2040 (compared with 19 percent in 2011). Nuclear generating capacity increases from 101 gigawatts in 2011 to a high of 114 gigawatts in 2025 through a combination of new construction (5.5 gigawatts), uprates at existing plants (8.0 gigawatts), and retirements (0.6 gigawatts).

Coupled with retirements among the 120,000 people who work in the nuclear industry, this expansion means continued career opportunities building, operating and maintaining the nation’s fleet of commercial reactors.  And this is just the start.  In addition to the 100 commercial nuclear plants operating in United States, there are 335 in operation in other nations and 73 more under construction (including four in the USA).

Recently announced shutdowns of four nuclear energy facilities in the USA has done little to dampen the demand for talent; the industry has more than enough demand for knowledgeable workers to absorb those displaced by plant closures. While some older nuclear plants will gradually go out of service over the next few decades they’ll be replaced with larger power plants that require larger staff sizes.  New technologies like small modular reactors may add even more jobs in advanced manufacturing and construction.

What does all this mean for career opportunities? Every nuclear plant employs at about 600 to 1500 people depending on the power plant size, the technology used, and the number of reactors at the facility.  In the USA alone the combination of modest expansion and hiring to replace about 40% of the workforce over the next decade means nuclear energy companies will hire 30,000 to 50,000 new engineers, operators, and technicians.  The numbers are even larger in other countries where growth will create more than 70,000 career opportunities as new facilities come on line.

More information about nuclear energy careers is available below:


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