Mike,

 

I figured it would be productive to sit down and write out expectations for the TF PDR which could serve as a basis for discussion.  Please review the list below and we’ll discuss it at your convenience.

 

1. Requirements.  Design requirements for the TF Coil System are documented in a Systems Requirements Document (SRD).  The SRD should be signed (or at least thoroughly reviewed and iterated).  Development of lower level specs should be apparent in the WAFs for final design.
2. Design versus requirements.  It should be shown that the design fully meets all requirements.  Where analysis results are cited, the memo or analysis report should be referenced.  Analysis results should show that the design meets design criteria, e.g. NCSX Structural and Cryogenic Design Criteria, not just provide a number representing a stress.  The electrical and mechanical integrity of the electrical insulation should be established along with the mechanical integrity of the conductor.  Requirements related to field errors should also be addressed, e.g. field errors from leads and transitions.  Where test results are cited, the test documentation should be referenced.  Where the design basis is incomplete, the activities planned to provide the missing data or analysis should be apparent in the WAFs, e.g. insulation testing to be completed during final design.
3. Analyses.  Analyses should be documented.  Memos are OK for a PDR.  For the FDR, the analyses should be documented in formal analysis reports prepared per project guidelines, signed, and checked.  Activities required to accomplish this should be apparent in the WAFs for final design.
4. Models and drawings.  The models and drawings defining the TF design should be reviewed for completeness and compatibility other stellarator core elements and promoted to Preliminary Design Release level.
5. Design documentation.  The Design Description for Conventional Coils and Structures (WBS 13 and 15) should be updated to reflect the design presented at the TF PDR.
6. Chits.  All chits relevant to the TF from prior design reviews should be satisfactorily resolved.
7. Standardization.  Planned use of standardized parts should be addressed when presenting and documenting the design.  In this case, I believe the electrical leads, coil I&C, co-wound flux loops, and epoxy formulation qualify as standardized parts.
8. Cost and schedule.  Provide a cost basis and cost and schedule estimates which are consistent with the preliminary design.
9. Interfaces.  Interfacing systems are defined in the SRD.  At a minimum, scope sheets should be prepared to identify the actions required to define all interfaces.  The activities required to define the interfaces and provide whatever interface documentation is required, e.g. ICDs, should be apparent in the WAFs.
10. Procurement plans.  Discuss how each of the elements comprising the TF coil system will be procured.  These procurement plans should be reflected in the WAFs.
11. Assembly, installation, and test.  The scheme for joining the wedge pieces with the windings should be discussed.   These activities should be apparent in the WAFs  It should be demonstrated that the TF design is compatible with the scheme for field period and final assembly reflected in the WAFs.  Plans for qualification and acceptance testing of the TF coils and for demonstrating the readiness of the system for operations should be discussed and should be apparent in the WAFs.  (The actual test plans and procedures will be developed following the FDR.  For the PDR, just provide an overview of what the plans are so we know that they are covered in our plans.)
12. Risk management.  This is extremely important for the TF coil system PDR.  The TF coils are critical components in many ways.  They are near the critical path – quality or production glitches in the procurement could compromise the project schedule, which in turn could have substantial cost risk.  They are projected to be costly items in their own right – the cost uncertainty represents significant cost risk.  Ditto for the uncertainty in how long it will take to fabricate 18 coils.  The TF coils are critical components in the sense that failure of a TF coil could compromise the experimental program, shutting down the device for a year or more – the coils must have ultra-high reliability, which places a premium on having a design which designs out failure modes, having a design that provides conservative design margins, and providing excellent quality control.  One of the more challenging design requirements is that the current center of the TF coils must be within 3mm of the ideal current center in the installed position – if not, plasma performance could be compromised.  Each risk should be identified and the strategy for mitigating that risk discussed.  Risk mitigation should be documented in the design description.  Implementation of that strategy should be apparent in the WAFs.

 

Reviewing the above, a checklist of documentation for the PDR would be as follows:

 

1. PDR presentation material
2. TF SRD
3. Updated Design Description for Conventional Coils and Structures
4. Catalog of design basis analysis memos
5. TF models and drawings (promoted to Preliminary Design Release level)
6. Updated cost basis documentation and cost and schedule estimates
7. Scope sheets for each interface

 

I believe the right path forward is this:

 

1. Get the requirements finalized so we are not evaluating the design against a moving target
2. Get Brad Nelson’s concurrence (as Project Engineer for Stellarator Core Systems, i.e. your supervisor) that the design approach taken is indeed the one we want to go forward with for final design and that it is on sure footing with respect to meeting its requirements – I am concerned that he has not been in the loop on making key design choices
3. Get the documentation together for the PDR (see checklist above) and let me know when it is ready
4. We’ll form a review committee, issue a charge, and schedule the PDR

 

Regards,

 

Wayne