From: Hutch Neilson [hneilson@pppl.gov]
Sent: Tuesday, December 09, 2003 9:27 AM
To: Mike Zarnstorff; Wayne Reiersen; Bob Simmons; Larry Dudek; Ron Strykowsky; Brad Nelson; John Schmidt; Hutch Neilson; Jim Lyon
Subject: Summary of NCSX SIT Meeting of 12/8/03
Summary of NCSX System Integration Team (SIT) Meeting of Monday, December 8, 2003

1.  Vacuum Vessel Schedule Risks
We are making progress in coming to closure on the critical vacuum vessel design decisions:

• We will likely retain the current vacuum vessel segmentation scheme. The alternatives have too many unknowns for this stage of the design, consequently high risk to the design schedule. We expect to confirm this decision at next SIT.
• This week, Art Brooks will tweak the vacuum vessel shell geometry to try to increase plasma-wall spacing within the existing segmentation and assembly constraints.
• On 350 C bake, we will try to wrap up the decision by next SIT, but the way things appear to be heading is:
  
  • The tube attachment issue can be resolved by eliminating the requirement to cool the vessel. If they only have to heat the vessel (a slow process), mechanical attachments (clips) can be used, avoiding the need for high-temperature epoxy or welding. Electrical heaters need to be installed on the ports. The program risk is that the cooldown time for 12 MW plasma pulses my be longer than 15 mins. The benefits are increased plasma-wall space and reduced operational costs and risk due to thinner PFCs that do not need a separate cooling loop, except possibly for local hot spots such as divertor plates.
  • The thermal expansion issue is probably limited to port interferences requiring some modifications of the port ducts, but currently thought to be workable. The homework still needs to be finished on this issue. ACTION: Goranson.
  • The thermal cycling of the vacuum vessel at ~400 C is thought not to be a feasibility issue but could be prohibitively costly. ACTION: Goranson to follow up with suppliers.
    
  The goal is to resolve the 350C bakeout issues this week and decide at the next SIT.
  

• In a separate discussion, Goranson advocated the need for 3D thermal modeling of the vacuum vessel and neighboring structure to address cooldown between pulses. This would be a new task not included in the current work plans. ACTION: Goranson develop and propose plan.
  

2. Modular Coil Schedule Risks

• CAD modeling of the MCWF is making progress and, it is hoped, will be resolved this week. The T. Brown approach is working well.  The Williamson approach is still being pursued. The Hargrove approach has been dropped. Hargrove is working on “tool solids” modeling needed by J.P. Pattern.  It is anticipated that the Brown approach will be able to model all three MCWF’s, without interferences. This has not been demonstrated yet but it is hoped to be completed this week.
• Structural analysis remains an issue, but resources have recently been added to the global modeling task (H.M. Fan) and we expect to make progress with simpler approaches in parallel, and have a story by the FDR. The plan for documenting all needed load cases still needs to be fleshed out and incorporated in the WAFs. ACTION: Williamson.
  

• In a separate discussion, Williamson advocated making fuller use of the prototyping activities to develop the process for accurately winding the coils. Multiple metrology approaches may need to be tested to determine the best approach for use in coil production. ACTION: Williamson follow up with metrology and coil winding groups to ensure needed tools are being procured and to develop the plan.
  

3. Technical Risks
Wayne led a discussion of critical technical issues and updated a tracking list which has been developed. Highlights not already covered:

• We do not yet have an adequate R&D plan to develop the reference material properties and design criteria, and resolving cure strain inconsistencies. ACTION: Brad, develop the SOW for the R&D program.
• We need the magnitude of field arrors from structural steel around the machine. ACTION: Wayne follow up with Brooks and Strickler to determine responsibility.
  

4.  CD-2 preparations

• The Change Control Board met on 12/8 to review changes to the GRD. A handfull of issues requiring follow-up was identified and assigned. It is expected that the GRD changes will be approved before the holidays.
• The PDR, PBR, and EIR disposition plans are out for review and response by the WBS managers by Friday, Dec. 12. ACTION: Neilson follow up.
• The ECP documenting changes from the PDR baseline to the CD2 baseline will incorporate review responses and any changes to the DOE funding profile. Project-initiated changes resulting from the WAF planning and updating processes will, as a rule, not be incorporated into this ECP but swept up at the next Lehman review. Exceptions will be considered case-by-case. They may entail calls on contingency.
  

5.  Next SIT Meeting: Monday, December 15, 2003 at 1:00 p.m. (Note special time.)


Summary by:
Hutch Neilson