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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Dai-Kai Sze, The ARIES Team
Fusion Science and Technology | Volume 26 | Number 3 | November 1994 | Pages 1061-1068
Fusion Blanket, Shield, and Neutronic Technology | Proceedings of the Eleventh Topical Meeting on the Technology of Fusion Energy New Orleans, Louisiana June 19-23, 1994 | doi.org/10.13182/FST94-A40295
Articles are hosted by Taylor and Francis Online.
A series of reactor design studies based on the Tokamak configuration have been carried out under the direction of Professor Robert Conn of UCLA. They are called ARIES-I through IV. The key mission of these studies is to evaluate the attractiveness of fusion assuming different degrees of advancement in either physics or engineering development. This paper discusses the directions and conclusions of the blanket and related engineering systems for those design studies. ARIES-I investigated the use of SiC composite as the structural material to increase the blanket temperature and reduce the blanket activation. Li2ZrO3 was used as the breeding material due to its high temperature stability and good tritium recovery characteristics. To reduce the activation caused by the using of Zr, isotopic tailoring is required. Also, W was selected as the divertor target. The activation caused by the Zr and W, even with isotopic tailoring, reduced the safety advantage for the SiC blanket. The ARIES-IV is a modification of ARIES-I. The plasma was in the second stability regime. Li2O was used as the breeding material to remove Zr. A gaseous divertor was used to replace the conventional divertor so that high Z divertor target is not required. We investigated the possibility of breeding without the use of Be. However, tritium self sufficiency could not be assured with the uncertainties in the neutronic data. The safety advantage of ARIES-IV was enhanced by the removal of the high activation materials. The physics of ARIES-II was the same as ARIES-IV. The engineering design of the ARIES-II was based on a self-cooled lithium blanket with a V-alloy as the structural material. Even though it was assumed that the plasma was in the second stability regime, the plasma beta was still rather low (3.4%). To achieve an acceptable neutron wall loading, the magnetic field is rather high. This put an extra burden on a self-cooled liquid metal blanket. It was determined that a self-cooled lithium blanket with bare walls was not acceptable for a reactor with ARIES-II type parameters. Therefore, an insulating coating is required to assure an acceptable design window to reduce the MHD pressure drop. The ARIES-III is an advanced fuel (D-3He) tokamak reactor. The reactor design assumed major advancement on the physics, with a plasma beta of 23.9%. A conventional structural material is acceptable due to the low neutron wall loading. From the radiation damage point of view, the first wall can last the life of the reactor, which is expected to be a major advantage from the engineering design and waste disposal point of view. Organic coolant was selected as the reactor coolant to reduce the operating temperature compared to He, and to reduce the coolant pressure and improve thermal efficiency compared to water. However, the use of organic coolant raised safety and decomposition concerns.