PEER REVIEW: details and data on the scope of unit 2

Details provided here are for estimating what equipment was seen in the scope effort, what could potentially be determined by further efforts, where water is potentially located and radiation levels along with corium location. While we may not be able to make many detailed conclusions there is the potential to extract more information out of this effort. Schematics along with known data are below.

Some questions already asked on the live blog:
The washout in the 4th video, is some of it radiation washout vs. light reflection, steam and other interference. If it is washout due to high radiation what does that tell us about the distance from the fuel and possible radiation level where the camera is?

Exactly how far down do we know water does not reside?
What is the total visual range of the camera?
What do we know from the unit 5 scope attempts that can be translated to the effort at unit 2?

Please leave thoughts or questions here or come post on the live blog to discuss.

Camera total range: 10 meters with an 8mm camera end
Camera radiation maxium: 1000 sVh per hour
Containment thickness at penetration point: 1.5 to 2 meters
Penetration to center of containment is 8.7 meters (this does not include containment wall thickness)
From penetration access point to bottom of containment is 6.31 meters
From penetration to edge of the pedestal is 6.11 meters
Penetration X-53 is at an elevation of 12490 OP

Penetration X-53 with “CRD” noted as a landmark

Elevation view of X-53 and the CRD

Layout of 1st floor with X-53 penetration point.

Measurements shown on the elevation drawing of Unit 1 for comparison. 6.31 meters to floor of containment.
8.7 meters from inside of penetration to center of containment. 6.11 meters from inside of penetration to outer
edge of the pedestal.

 Generic BWR pedestal layout with radius measurements

 Inside pedestal of unit 5

Close up of containment access point. Red is the penetration depth. Green is the CRD, Yellow is TEPCO’s estimated light range for the camera.

Total camera range of 10 meters imposed over unit 1 elevation drawing

Where TEPCO originally thought water would be before scope in unit 2. Blue line indicates where they thought water would be.

Horizontal corium theory based on corium movement at Chernobyl. Added here for contrast vs. where the camera scope was inside unit 2.

Photo of the unit 5 scope practice. The CRD is marked on this photo. The upright pipes resemble structures found in unit 2

CRD photo from unit 5 scope practice

more pipes inside unit 5 near the CRD

Pipes and box type object in unit 2 seems similar to the one in unit 5?

Paint peeling from containment

Whiteout on camera?

Camera details provided by TEPCO

Links to all images captures of unit 2 scope project
Details on camera and work to be done 
Part 3 based on Video 4
Part 2 based on Video 2-3
Part 1 based on Video 1 

Videos of scope inside unit 2
Video 1
Video 2
Video 3
Video 4 (part 1)
Video 4 (part 2)

PDF showing intended scope process and some photos inside unit 5 
PDF with floor plan and how unit 2 will be scoped
PDF of scope used


This article would not be possible without the extensive efforts of the SimplyInfo research team
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