Archive for the ‘Nuclear Tourism’ Category

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Chernobyl Turbine Hall, November 2016

February 1, 2017

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

The mercury-vapor lights in the ChNPP turbine hall barely turn on in the freezing darkness of Ukrainian winter, emitting a harsh buzz but only weak, jaundiced illumination.  With no climate control (the on-site heating plant is shut down because the fuel needed comes from Russia and is prohibitively expensive), corrosion has set in on every available surface.  Across the turbine decks, in vast heaps, lie demounted valves, piping, bearings, casings, and of course, pieces of the turbines themselves, all of it too radioactive to go anywhere else but here.  Made in Ukraine at the Kharkov Turbine Factory (now Turboatom), the vast machines are destined to rust away while similar turbines continue to turn at more auspicious nuclear power plants throughout the former USSR.

In addition to the turbogenerators, the turbine hall also contains condensate and feedwater machinery, some of which may be seen in the photos in the gallery here.  The hall is being temporarily used to store radioactive structural components of the highly-contaminated ventilation stack that once stood between the Units 3-4 reactor buildings. Click below to watch a Bionerd video about the turbine hall:

 

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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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Chernobyl Unit 2, November 2016 (Part I)

January 17, 2017

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

This photo gallery documents the main circulation pumps and the repair/transport corridor in Unit 2 at the Chernobyl Nuclear Power Plant as they appeared in mid-November 2016.  Unit 2 operated until a fire damaged the No. 4 generator and the unit’s feedwater machinery in October of 1991, after which the unit was permanently shut down.  It is an example of the earliest variant of the RBMK plant design, following the model of the Leningrad units.  The main circulation pumps in these earlier units are aligned on an axis perpendicular to the turbines and on the +1.0m elevation, whereas in the later generation of RBMK units (e.g. ChNPP Units 3-4), the pump engines are on the +12.5m elevation and aligned parallel with the turbines so that twinned units could share the same MCP engine halls and associated cranes.  The earlier-generation units are smaller than the later generation, mainly because they lack a steam-condensing “accident localization system” beneath the reactor.

Locations shown in the photo gallery may be identified on the following plan of the +1m elevation in the Unit 2 reactor building, taken from plant safety documentation:

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New life for Silkwood plant

November 20, 2016
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Plutonium vault in the former Kerr-McGee Cimarron Fuel Fabrication Plant. Some 50 lb. of plutonium went unaccounted for at the Cimarron plant during the Silkwood years due to sloppy handling and accounting uncertainties.

Stigma has a long half-life.  42 years ago, a young woman named Karen Silkwood was found dead in her wrecked car on the side of Oklahoma State Highway 74.  She had been a laboratory worker at the nearby Kerr-McGee Cimarron Fuel Fabrication Plant as well as an OCAW union officer, and at the time of her death she was on a journey south to Oklahoma City, purportedly carrying evidence of unsafe work conditions and nuclear material diversion to a meeting with union representatives and the press.  After Silkwood’s death, the alleged smoking-gun documents were nowhere to be found.  Conspiracy theories blossomed in the absence of conclusive understanding into the circumstances of her death.  The idea that Kerr-McGee management had her “bumped off” gained a major following, despite no evidence underpinning this suggestion and a competing toxicology finding of methaqualone in Karen’s blood.  Two years later, in 1976, the Cimarron plant shut down in ignominy.

In 1983, Meryl Streep played Karen Silkwood to critical acclaim in a major motion picture that served to cement the murder theory in the popular imagination.  While the basic plausibility of the alleged murder conspiracy fades with each passing year, it endures as fact in the folk wisdom of numerous anti-corporate and anti-nuclear advocates.  As for the Kerr-McGee plutonium fuel plant, it too endures; and after decades of vacancy, is poised to rise from the ashes of its scandal-ridden nuclear past as a manufacturing facility for aircraft parts.  This is particularly remarkable, as very few former nuclear facilities survive cleanup intact, and few structures survive decades of neglect to the elements.  (Some of the surrounding lands, however, remain under NRC license and are still being remediated for contaminants.)  I visited the site in the fall of 2016, and would like to thank Jeff Lux, project manager and engineer, for his generosity and willingness to take me around this landmark in the cultural history of nuclear technology in the USA.

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Manhattan Project National Historical Park, Part I: B Reactor

June 29, 2016

In November 2015, the US National Park Service and Department of Energy came to an agreement outlining a new national park, one that would focus on the history of the American effort in World War II to develop nuclear energy for warfare (the “Manhattan Project”).  B Reactor at Hanford is already open with scheduled tours managed under this arrangement.  It was the world’s first plutonium production reactor, designed and built under truly remarkable wartime circumstances, and it operated from 1943 to 1968.

By special arrangement with Colleen French, the DOE’s park coordinator at B Reactor, I was able to visit the reactor at my own pace with a small group of nuclear enthusiasts in March.  Geiger counters, scintillators, and gamma spectrometers also came along, although there was some official resistance to their presence.  And this brings me to the two questions I hoped to answer in visiting this place: firstly, how are the NPS and DOE handling the interpretive challenges inherent in opening a radiation facility to the general public of all ages; and secondly, will hardcore “nukeheads” like me find a sufficiently authentic and engaging experience given the constraints imposed by preparing the site for the public.  My experience at B Reactor was heartening.  The reactor remains an interesting radiation environment (see photo galleries below), and its staff have made rational choices in seeking balance between public safety and respect for the authentic realities of the place.  For nerds with the right instrumentation, the radiation signatures in various parts of the building tell little stories about what happened there.  Reactor equipment has been lovingly left intact throughout–down to the decommissioning tags from 1968.

The radiation signatures at B Reactor were thrilling to me, like little ghosts of the past jumping out to whisper their secrets, but of course, radiation is sometimes feared and loathed.  I empathize with administrators who worry that the crackle of a Geiger counter might repulse or anger some visitors.  My own view is that all kinds of genuine reactions, ranging from enthusiasm to fear, are valid, and all should be tolerated.  Scientifically-informed judgement should guide how safety is established at such sites, but it is still possible to be welcoming and accommodating toward visitors expressing a broad spectrum of reactions, including both the occasional phobia and the occasional super-demanding “nukehead” (e.g., me).  The sites in the nascent Manhattan Project National Historical Park belong to all of us–the enthusiastic and the timid, the plant operators and the “downwinders,” the bombers and the bombed.  Uniting us all is interest in the history, and I am encouraged by the respect for history I witnessed at B Reactor this year.  Best wishes to the other Manhattan Project park sites as they open doors to the public.

Now what you probably came here for: captioned photo galleries!

Reactor operating position and safety systems

B Reactor offers a window into the minds of reactor designers who had never before worked at the power scale envisioned for plutonium production, but who still thought of a surprisingly comprehensive suite of instrumentation, controls, and safety systems, many of which have analogous descendants in modern reactors.  Notable are multiple ranges of power measurement instruments, flux profiling and distribution control in the core, gravity-dropped safety rods, a backup gravity-operated shutdown system in case the core sustained mechanical damage, emergency core cooling tanks in case of a water delivery failure, electrical and hydraulic redundancy in the horizontal control rod system, seismometer SCRAM in case of earthquake or war; and individual fuel channel pressure measurements.

Horizontal control rods

Horizontal control rods were used to regulate the reactor power and adjust the flux distribution in the core.  Some of the rods were hydraulically driven, others electrically driven.  The “inner rod room” lies directly above the control room and is still quite radioactive and off limits (even to me).  This is where withdrawn rods would actually reside after exiting the core.  Their drive mechanisms are on the other side of a heavily-shielded wall, the “outer rod room” (shown in most of these photos).  Radiation is detectable in the outer rod room, and particularly in a floor drain under it.  The radiation here mostly comes from cobalt-60, a product of neutron activation of steel.

Reactor discharge face

Irradiated nuclear fuel slugs would be pushed out the back of B Reactor into a water-filled trough.  This is a truly exciting part of B Reactor, since the radiation levels are bordering on high even today.  The gamma spectra reveal the activation nuclide europium-152, which we know accumulated in the cooling water system (see below) but could also be formed in the pile graphite and shielding concrete; and long-lived fission product cesium-137.  The Cs-137 was formed in fuel and subsequently escaped through ruptures and leaks in the fuel cladding.

Irradiated fuel storage pool

After being irradiated, short-lived radioactivity in the fuel was allowed to decay for several months before chemical processing to recover the plutonium was undertaken (typically, unless one was doing a “green run,” in which case you would process it right away).  In common with the reactor discharge face area, radiation levels in the fuel storage pool at B Reactor remain a little too high for public access.  However, the wooden decking over the pool can be viewed through a window.  The cause for the high residual radioactivity is none other than our old friend, cesium-137, which escaped from damaged fuel.

Above and below the reactor

At the “pile top” we find the gravity-aided vertical safety rod (VSR) mechanisms, as well as hoppers full of boron carbide balls–a last-ditch shutdown feature in case the VSR guide tubes warped from thermal-mechanical damage in the core.  Below the reactor is a small basement (the “Beckman room”) where reactor flux measuring instruments were located.  Today, the basement contains an impressive stash of radioactive tools and fuel handling equipment, probably left in position from shutdown in 1968.

Cooling water systems

B Reactor employed a once-through cooling circuit: water was drawn from the Columbia River, treated, pumped through the reactor’s process tubes, allowed to “cool down,” both thermally and radiologically, in an outdoor basin, and then discharged back into the river.  The discharge water sampling station in B Reactor allowed chemists to monitor their effluent, alerting them to damaged fuel or water treatment problems.  Today, the sampling station remains a bit radioactive, with the rare-earth activation nuclide europium-152 being wholly responsible for the measured gamma radiation there.

Reactor grounds

The back yard of B Reactor has some interesting stuff, like pallets full of channelized reactor graphite and drums full of unused boron carbide shutdown balls.  Several railroad cars used to transport irradiated fuel are now permanently displayed on the grounds, and these are sizzlin’, producing peak gamma exposure readings in excess of 5 mR/h, all due to residual Cs-137.

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2015 Photos from Chernobyl

June 11, 2016

I have been extremely slothful in attending to my blog, and if anyone still reads it, I apologize and thank you for your patience!  I’m attempting to catch up for the last few years in my spare time, posting the content and photos I’ve intended to publish more punctually but somehow haven’t found the time to do yet.  The following images were taken at Chernobyl Nuclear Power Plant in September of 2015 (with a couple from 2013, another trip I somehow managed not to document on my blog).  Amazing progress has been made on the New Safe Confinement.

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