Engineering Operations

OH water leak:• Water leak is located ~ 4.5” into the upper OH lead.

Leak location @ 2 o’clock

Cooling hole 0.188 in. dia.

Engineering Operations

OH water leak:

Leak first seen between conductor & Insulation

Engineering Operations

OH water leak repair preparation:• The upper TF hub disassembled to provide access.

•Repair Area

Engineering Operations

OH water leak repair options:• The mechanical and leak repairs will be addressed separately.

• A pin-hole leak can be repaired with a leak sealer. For a crack, the cooling hole will be reamed to a larger diameter to accommodate a cooling sleeve. An O-ring at the end of the sleeve will be compressed at the end of the reamed hole.

0.638”

0.394”

•OH Conductor

Engineering Operations

OH stress crack repair (IF REQUIRED):• A copper bridge secured to the conductor and lead block using

either clamping or a TIG-braze.

•Stitch TIG- Braze 1/8 “ fillets around support block to lead block

•TIG- Braze 1/8 “ fillets around support block to conductor

•Copper support block fits snuggly around conductor and attaches to lead block

•OH Center

Engineering Operations

OH Lead mechanical support:• A G-10 block added to support vertical and twisting loads.

Engineering Operations

Insulation repair:

•Epoxy/glass ground wrap around both conductors

•Turn insulation on lower conductor untouched

•Kapton insulation added to repaired conductor

•G-10 spacer between conductors

Engineering Operations

Post repair monitoring:• Sight tubes added to allow

periodic (daily?) inspections w/boroscope.

• Leads can be brought out to electrically monitor the resistance of the conductor or the flex link

• A leak divertor with an electronic water monitor is possible.

Engineering Operations

LLD Heating:• A “house air” heater to heat the 4th LLD plate has been

assembled in the VPL and tested to 12CFM at 300C.

Engineering Operations

Updated FY10 Schedule:• NSTX has completed 2 weeks of the planned 15 week run.

• We expect to resume operations on May 24th, but could be ready a week earlier based on the scope of the repair.

• Assuming a maintenance week each month, NSTX will need to run into September this year.

• Need to determine the scope of the upcoming outage. A timely start to the FY11 run is needed to support an aggressive NSTX upgrade schedule.