Posts Tagged ‘control room’

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Chernobyl Unit 4, November 2016

January 19, 2017

Please select any photo in the galleries for a larger version and descriptive caption.
In November 2016, the massive New Safe Confinement arch slid over Unit 4 of the Chernobyl Nuclear Power Plant, and the old “Sarcophagus” that had defined the appearance of the damaged unit for 30 years receded from view.  Over the last three years, the iconic ventilation chimney shared by Units 3 and 4 has been disassembled as well, and now rests in pieces in various places (including the deck of No. 5 turbogenerator).  Inside the unit, work continues to finish the Perimeter Closure Project–the effort to hermetically seal off the east and west boundaries of the New Safe Confinement from the rest of the power plant.  Floor by floor, barriers are going up.  The memorial to Valery Khodemchuk, the first victim of the 1986 accident whose remains have never been recovered, has been removed from its old location at the northwest end of the chemical treatment and ventilation block, and will be reinstalled somewhere else once the project is finished.  The photos in the second gallery show the state of the Arch and the Local Zone around Unit 4 only several days before the Arch began its movement, and are certainly among the last photos of the old Unit 4 exterior we have come to know and love.

I was honored to have Bionerd along for this trip, and her video record of the visit inside Unit 4 is on YouTube here:

Finally, here is a gallery showing the Arch of the New Safe Confinement and some of the “Local Zone” surrounding Unit 4.

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Chernobyl Unit 2, November 2016 (Part 2)

January 18, 2017

Please select any photo in the galleries for a larger version and descriptive caption.

The reactor hall and control room of Unit 2 at the Chernobyl Nuclear Power Plant are documented in these photo galleries and companion video.

Room 612/2 (Central Hall); Room 804/2 (Refueling Machine Control Room)

The RBMK reactor design features an ability for online refueling: withdrawal and insertion of fuel bundles while the reactor is at power.  The charge face with its 2000-some channel covers is sited above the reactor within a massive “central hall” that is built like a hot cell, with concrete entryway mazes and leaded-glass windows for refueling operators.  The dominant piece of equipment is, of course, the crane-mounted RZM (refueling machine).  Also in the central hall are two spent-fuel basins, fresh fuel and instrumentation storage hangers, and metal plate covers for accessing the upper steamwater pipelines from the reactor and the peripheral ionization chambers.  Unit 1 and 2’s central halls are on the +20.2m elevation, typical of first-generation RBMK plants, while the later Unit 3 and 4 central halls are on +35.5m.  The chief reason for this is the introduction of a steam-suppressing pool and “Accident Localization System” below the reactor in the later design.  Unit 2 has been offline since a turbine hall fire in 1991, and is defueled and dry (all spent fuel is in the ISF-1 facility).  The spent fuel pools in the reactor hall are also dry, but are currently being used to store fuel support stringers.  Measured exposure rates in the reactor hall range from surprisingly low (3 mR/h on uncovered fuel channels on the “pyatak” or reactor lid) to surprisingly high (2 R/h close to a point source-maybe a fuel flea?-on a fuel stringer).  Like other RBMK reactors, including Unit 3 at Chernobyl, ChNPP-2 participated in transmutation doping of silicon for the Soviet semiconductor industry.  A single channel ordinarily used for the control and protection system was assigned for this application.

Video (via YouTube)

Room G364/2 (Unit 2 Control Room)

The control room, like all others at RBMK plants, is situated nominally at +10m elevation in the “deaerator stack” abutting the turbine hall.  The tray-type deaerators themselves, and reactor steam and feedwater piping, are in compartments directly above the control rooms, leading to some interesting hypothetical accident scenarios whereby radioactive water might invade the control rooms from above.  At ChNPP, the Unit 2 control room has a notable radiation “hot spot” above T Desk at the west end, possibly due to contamination in the steamwater piping compartment upstairs.

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Inside Peach Bottom Atomic Power Station

May 26, 2012

The two boiling water reactors at Peach Bottom Atomic Power Station are of the BWR/4 product line from General Electric and are housed in Mark I (“lightbulb”) containments.  They share a common turbine building and a common control room.  Electrical output is about 1200 MW each, leaving the station at a respectable 500 kV to feed the power-hungry metropolitan areas of the northeastern United States.  Condenser waste heat is rejected to the Susquehanna River, supplemented during particularly hot weather by some small forced-draft cooling towers.  Peach Bottom’s official name harkens back to 1958, when “atomic power” was a celebrated novelty, and construction began on a unique gas-cooled reactor at the Peach Bottom site.  The GCR operated until 1974.  Units 2 and 3 came on line that same year on a site on the right bank of the Susquehanna River just north of Unit 1.

Nuclear power plants have understandably committed unprecedented attention to safety and security in the last decade or so.  An unfortunate side effect has been that those of us who don’t work in these facilities have scant resources to help wrap our heads around their scale, layout, equipment, and operations.  With that in mind, I’m profoundly grateful to Exelon Corporation’s Peach Bottom staff, and in particular Jim Kovalchick, director of security, for allowing the comprehensive tour on which these photos were taken in April 2012.

To see pics with my descriptive captions, you must click “permalink” in the slideshow view after clicking the thumbnails below.  Sorry that’s not obvious, but WordPress.com has gone all knuckle-head in the tech department this year.  If you want to see the FULL SIZED photo: (1) click the thumbnail; (2) select “permalink”; (3) click the larger photo.  Whew!

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Visiting Vogtle and Bellefonte Nuclear Power Plants

September 6, 2011

The control room in Unit 2 at Plant Vogtle, August 12, 2011, just before 5:00PM. Reactor controls at left, balance of plant on the right. The reactor is at full power. A routine maintenance and refuelling shutdown is planned for the Fall.

The American South is widely seen as the most viable US market for new nuclear power plants.  Although the “nuclear renaissance” faces serious obstacles in the post-Fukushima world, if reactors are to be put on the grid then the South is almost certainly where it will happen first.  Dominion’s North Anna plant, which I visited in 2009, plans to add an ESBWR. This August 12th and 15th I accompanied Atlanta fusion hobbyist Chad Ramey, his father, and friend Steven Shaw to two other southern nuclear nurseries. Plant Vogtle (pronounced “VO-gel” in local dialect) is an operating two-unit Westinghouse PWR plant of recent vintage that is adding two additional Westinghouse AP1000 reactors.  Bellefonte Nuclear Generating Station, by marked contrast, is a 37-year-old never-completed Babcock and Wilcox PWR plant with two units, one of which TVA elected to complete by unanimous vote of its board on August 18.

Nuclear power plants are some of the most uptight and inaccessible places on the planet unless you work there, so I’m grateful to Mike McCracken at Plant Vogtle and to Chris Griffin at TVA for accommodating us.  I’m especially indebted to Mike for all the photos from Plant Vogtle.   (Unfortunately there is a strict no-photography policy in place at Bellefonte, so my gallery contains just two exterior shots.  However, we visited the reactor vessel head, a steam generator, spent fuel pools, a cable spreader room, and the well-preserved ’70s-vintage control room, among many other parts of the plant.)  Click any image below for a larger version with caption.

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Inside Chernobyl Nuclear Power Plant 2011, Part II: Deaerator Corridor and Unit 1 Control Room

August 8, 2011

More interior photographs from the Chernobyl Nuclear Power Plant, this selection focusing on highlights of the Unit 1 control room and the building’s perhaps most distinguishing interior feature, its 600-meter-long “Gold Corridor.” Right-click any photo and select “open in new window” (or equivalent) for a larger version with my caption.

For this summer’s photos of the Unit 3 end of the power plant, see this post.

Our photos from ChNPP last year are displayed at this site.

The floor plan below is compiled from an official plant safety document and is meant to help illustrate the geography of the power plant on the +10-meter elevation, near Units 1-2.

+10-meter floor plan, Phase I, Chernobyl Nuclear Power Plant

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