Project Conference Call

30 July 1997



Participants:

(DOE) -
(UCSD) Miller, Najmabadi
(PPPL) -
(GA) Stambaugh
(UW) Khater, Mogahed
(FPA) -
(RPI) -
(ANL) Sze
(MDA) Waganer

Administrative

Farrokh Najmabadi noted that there were no significant administrative actions to mention. Miller, Najmabadi, Tillack, and Waganer (and J. Davis) are planning to attend and participate in the Fusion Power Associates Symposium, "Pathways to Fusion Power", in Colorado during 27-29 August. The next meeting is still scheduled for all day on both Thursday, Sept 25 and Friday, 26.

Les Waganer noted that effective 4 August, MDC will be merged with Boeing to become The Boeing Company. Company letterheads, signs, logos, and E-mail addresses will be changed (new addresses are lester.m.waganer@boeing.com and john.w.davis@boeing.com) but little else is anticipated to change. [Let Waganer know if the new Boeing mail system is causing you problems.] PS, The new Boeing High Energy Systems Web page address is http://www.boeing.com/ assocproducts/hienergy/ in case you reference or link to it.

Plasma Physics

Steve Jardin did not participate in the call, but Ron Stambaugh gave a quick update on GA activities. He noted that the PPPL and GA analyses and results seem to be converging on a common basis. TK Mau is currently at PPPL to confer with Martin Peng. Ron S. questioned if the modified coil locations have been assessed. Specifically, would the maintenance schemes allow the PF coils to be closer and/or the TF coils to be smaller? Could the PF coils be located inside the TF coils? Farrokh had discussed these topics with Steve Jardin but the issue has not been fully investigated or resolved. The present TF and PF coil configuration is somewhat of a legacy item from the Reverse Shear (RS) design, and the new groundrules for an ST/LAR configuration have not been fully or rigorously investigated. The coils could be smaller and/or interleaved, depending on other factors such as the coil connections, coil leads, and maintenance provisions. One difficulty is that the PF coils will likely be S/C; and when inside the TF, the cooling of the coils and TF coil connections are key issues. Steve had investigated some of these geometry effects, but could not seem to achieve the triangularity required.

Ron Miller noted that JSOLVER could position the coils closer to the TF coils. The outer cryostat (also a legacy from ARIES-RS) will be removed, with individual cryostats around each PF coil. These effects need to be added to the codes.

Engineering

Mark Tillack was on vacation but several others reported their status.

Blanket and Thermal Conversion - Dai-Kai Sze had several questions or concerns:

Configuration and Maintenance - Farrokh Najmabadi reported that there has been no progress on the maintenance and configuration task.

Safety Analyses - E. Mogahed has constructed a new model for the LOCA. The busbar is assumed to be the ultimate heat sink and is located outside the main power core (do not use the R-word). However he was not sure of the dimensions to use. R. Miller and W. Reiersen will coordinate to determine suitable busbar dimensions for E. Mogahed to use. Elsayed said his model is now using the wedge- shaped center post design.

Hesham Khater noted that one of Mike Corradini's students at UW is working on the safety analysis of the lithium and water reaction, which may be applicable to future ARIES work. There is added capability being incorporated into their existing code. In regard to a question raised by W. Reiersen at the Madison meeting, Hesham said that the waste from an unshielded aluminum centerpost would be acceptable under 10CFR rules, but the Fetter limits would result in a level of Al26 that is double the allowable limit for Class C disposal. If the centerpost is shielded, the disposal of the aluminum centerpost would be acceptable and the shield would be thinner than the one for copper (@ 30 cm).

High Heat Flux Components - No discussion.

Systems Studies

Ron Miller stated that he and Chuck Kessel have conferred. Chuck generated a EQDISK file for the A=1.6 regime. Ron has now developed systems code results for aspect ratios of 1.25, 1.4, and 1.6, with the latter looking much more favorable. For the 1.6 case, the current requirement is reduced, which makes most other data more favorable. More space is available in the center column, a better recirculating power fraction is obtained, and a smaller machine is forecasted. He will report the 1.6 strawman sometime in advance of the September ARIES meeting.

Ron turned on the availability subroutine in the systems code. Although the maintenance data has not been validated, the preliminary results were generally negative in the availability (and COE).

Dai-Kai noted that when we approach the 1.6 aspect ratio (or so), breeding only in the outboard region may not be adequate and we have to start breeding on the inboard side also. Ron agreed that this effect had not been included and will have to be incorporated at a future time. However, both agreed the crossover point has not been determined.

Alternate Applications

Les Waganer reported that he incorporated into his alternate application database some modifications from several suggested alternate weighting schemes resulting from the Madison meeting presentation. The presentation was modified, based on suggestions from Bill Dove and Farrokh Najmabadi, for use in the presentation to DOE-Office of Fusion Energy Sciences, namely Anne Davies and others. The DOE personnel generally agreed with the approach and results and suggested a more in- depth investigation within the available budget. The essence of this presentation will be given at the FPA symposium in August. Farrokh also gave the results of the ARIES-RS study to a subset of the same DOE audience.