LOT 201.17 Incore NI’s

Question 1

• LOT 201.17 Incore NI’s*
• • *

How many fission chambers and thermocouples are there?

Answer 1

• *6 Fission Chambers**
• Provide flux mapping of the core*
• U₃O₈ enriched to 95% U₂₃₅*
• *50 Thermocouples**
• Train “A” and Train “C”*

Question 2

• LOT 201.17 Incore NI’s*
• • *

What are thimbles and thimble guide tubes?

Answer 2

Thimble Guide Tube:

Tubes that are welded into the bottom of the Rx Vessel

Movable detector thimbles are lowered into thimble guide tube

Mechanically sealed (compression fittings) at top of the reactor

Dry inside guide tube allowing detector to move vertically in reactor

Thimble:

Movable miniature detectors