Summary of NCSX SIT Meeting of Monday, May 5, 2003

1. Critical Technical Issues

* Modeling of the Z01 coils is progressing, but completion is still about a week away (Brad)

* Assessment of the "E04" coils.

-Physics (various inputs): The ongoing PIES run is reportedly seeing some deterioration in the neighborhood of the 6/9 island.  About 10% of the plasma volume has been lost. It may be recoverable with some tweaking of the coil currents to shift the iota profile.  The assessment of physics properties has not been carried out yet. Have coil data been delivered to Physics yet?

ACTION: Hutch follow-up with Art Brooks and Physics team.

-Engineering (Brad): The E04  coils that Art presented last Wednesday looked better, at least for coil 1, and we could change to this when and if appropriate.  Coil 3, or C, shows very little, if any, change between the Z01 and E04 configurations.

-We are not in a position to switch to E04 at this time, because as yet there has not been a successful physics validation.

* Keystoning and control of the winding pack dimensions.

-The 4-cable conductor does not appear to be a good solution to the keystoning problem, so we are back to the single-cable conductor. Forcing the conductor into shape can be done to some degree but is limited by concerns about compromising the insulation if too much pressure is applied.

-Brad proposed: It may be possible to accomodate the keystoning problem by expanding the space available in appropriate places according to algorithms developed through more keystoning R&D. (This means that the winding form may have to be machined differently to accommodate keystoning.)  Brad suggests winding a single pancake, circular coil with 30 turns or so, starting with the smallest radius we expect in any coil.  We can measure any 9 turns on the this winding and correlate the total stack height and the stack center (it won't be in the middle, since the first turns will keystone more than the later turns).  Turns 1-9 would represent the worst case (shorter and wider pack) and turns 22-30 would represent a much more benign situation.  We can wind one test pancake the hard way and a second test pancake the easy way to get a correlation for lateral and radial deformation respectively.

This seems like a practical plan, and Engineering is revising the R&D program to accommodate it.

* Splice in the conductor. The baseline is no splice, but a splice would be advantageous for field errors if it would work. Engineering feels it is not a big impact on the R&D plan to investigate it before the PDR.

2. Release of drawings to MCWF suppliers for prototype fabrication

The MCWF suppliers will soon be needing us to identify the drawings we want them to use for prototype fabrication. We may wish to authorize them to proceed with the best-available model at the time, rather than wait for the Z01 modeling to be completed, in order to keep the R&D work on schedule. If so we need to address concerns raised by PPPL management about proceeding in a way that precludes the possibility of using the prototypes as real coils. A recommendation from Engineering is needed.

ACTION: Brad, Phil, with support from John.

3. Re-baselining activity (Ron)

* Cost reviews are starting this week with WBS 14 and 18 (J. Chrzanowski's scope). WBS 25 (NBI, T. Stevenson) will be scheduled for later in the week. WBS 82 needs to be postponed until both Reiersen and Neilson are available.

* The PPPL Institutional Plan for FY04-08 is being prepared. An estimate of annual operating costs is needed for FY-08. (Also needed for CD-2).

ACTIONS:

-Facility Ops costs: Ron follow-up with Mike Williams, who is updating previous estimates.

-Upgrade costs: Hutch send to Ron.

-Research Costs: Hutch provide estimate.

4. System Engineering Tasks (Bob)

*  Bob indicated that only minor revisions to the Project Execution Plan are needed to conform to new DOE orders and project changes since the CDR. An internal review has been conducted, and the next step is to cirulate the PEP for concurrent review among the DOE signatories.

ACTION: Bob coordinate external review with Greg Pitonak.

*  Bob requested prompt attention to outstanding documents awaiting signature approval. See follow-up e-mail from Bob.

*  Bob recommended the project identify tasks requiring Davis-Bacon review and initiate necessary actions.

ACTION: Bob follow up.

5. Cost drivers (discussion)

How will we react to to nasty surprises on cost?

* Reduce weight?  Once structural requirements are understood, we can investigate removing material to reduce cost and eddy currents. It is argued that trying to do so by making the structure thinner could make casting more difficult and move the cost in the wrong direction. Making bigger holes is likely possible, but may not save that much in fabrication cost. We concluded that this needs more near-term attention with increased emphasis on cost optimization in the supplier workscope. We should  not wait for nasty surprises.

ACTION: Brad, Phil, work with suppliers.

* Relax tolerances?  Tolerances may be our primary cost driver from component fabrication all the way through final assembly. We don't know yet if the tolerances we have set are affordable. How will we react if they ae not? Re-allocate tolerance budgets?  Rely more on trim coils?  Recent PIES calculations of some of Art's coil perturbations indicate that Art's analysis may be very conservative!  If this conclusion holds up, can we take credit and relax tolerances?

5. Next SIT Meeting:  Monday, May 19, 2003. (No SIT meeting next week)

Summary by:

Hutch Neilson