NCSX Memorandum

To: T. Brown, A. Brooks, H-M. Fan, B. Nelson, D. Williamson, M. Cole, P. Goranson, R. Hatcher, C. Neumeyer, L. Dudek, P. Heitzenroeder, R. Ramakrishnan, J. Chrzanowski, L. Dudek, A. Klink, H. Kugel

CC: J. Schmidt, H. Neilson, J. Lyon, S. Hirshman, M. Zarnstorff, A. Reiman. L. Berry, D. Strickler, R. Simmons

From: W. Reiersen

Date: 1/18/2001

Re: Minutes of 1/17 Engineering telecon

An engineering telecon was held on January 17. The objective of the meeting was to leave with a clear understanding of what work and deliverables are required to be completed in the next six weeks.

Phil Heitzenroeder started the meeting by reporting on some design features that appear desirable for assembly. He would like to pre-assemble the stellarator core in thirds, if possible, prior to bringing the sub-assemblies into the test cell for final assembly. The best place for pre-assembly would be the empty TFTR test cell. Two concerns with assembling the stellarator core in thirds are size (can we fit it through the door into the NCSX test cell?) and weight (can we lift one third of the stellarator core with an upgraded overhead crane?). Heitzenroeder argued for a bolted joint on the v=0.5 plane for final assembly. With a 150C bakeout (assuming a 350C stand-alone liner), the bolted joint could use double Viton seals with a pumped inter-space. The bolts would be tightened from the inside of the vacuum vessel. This should create a reliable joint and avoid problems associated with welding (weld distortion and very tight space) during final assembly. This would allow many of the in-vessel components to be installed prior to final assembly and greatly expedite the assembly process. Another advantage of the bolted joint would be that the machine would be disassemble-able. This could be a significant advantage in the event that a major failure or reconfiguration was required. The main concern appeared to be the extra space required for the bolted joint.

The three (one-third) machine sectors would be brought together by moving them radially inward. Nelson indicated that it might be necessary to bring the three sectors together simultaneously to avoid interferences. Brown will develop a concept for the base assembly that is consistent with this assembly approach.

The next Engineering telecon will be held next Wednesday, January 17, at 1:30pm. Please provide the following information in advance of the meeting:

Assess feasibility of bringing in one-third of the stellarator core into the NCSX test cell and lifting it with an overhead crane (Chrzanowski/ORNL)

Provide comparative assessment of bolted v. welded joint for final assembly, recommendation for PVR (ORNL)

NB access at the reduced size (Cole)

Possibilities for beam scraping to reduce horizontal width requirements (Kugel)

Prospects for manned access on boom mounted creeper through port adjacent to NB port (Cole)

Why do we have fully potted coils and what are the associated DT (J²t) limits (Nelson)

Further thoughts on the free-standing, bakeable liner including cost impact, selection of VV material (Nelson)

Assess technical feasibility of mounting trim coils on inside of 150C VV (Nelson)

Impacts of eliminating PF4 (Reiersen, Cole)

Selection of winding cavity design – I-beam? T-section? L-section? (Nelson)

Assess technical feasibility and cost implications of using cast aluminum instead of SS (Nelson)

What do we think trim coils will look like (Brooks)

Cost impact of reducing the number of NB in TPC from 4 to 2 (Kugel)

Cost impact of reducing the number of circuits in Day One configuration from 10 to 6 (Neumeyer)

Impacts of not disassembling PBX, recommendation (Chrzanowski)

Current tally of costs requested by Director’s Office (Simmons)

1. Previous baseline estimate and contingency used in the presentation to FESAC

2. Present estimate for 1.7m option

3. Present estimate for 1.4m option

4. Actual NSTX costs (mapped into NCSX WBS as closely as possible)