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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.

3 comments

  1. why it’s prohibited to stand on the reactor lid?


    • Probably just the risk of ankle injury, since so many of the protective covers are out of place.


  2. What parameters did the fuel channel cartogram in front of A desk display? I saw in another post on your site that it was related to the SKALA system but I’m curious about what it actually indicates to the operator.



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