NSTX-U 2nd Neutral Beam Relocation

Authors: N. Atnafu, M. Cropper, J. Edwards, K. Gilton, T. Stevenson, M. Viola

Abstract: AThe NSTX-U project required doubling the Beam Injection Power and extending pulse length. As a result, a second neutral beam (BL2) was brought in from the old TFTR Test Cell. The TFTR beam line had a Tritium contamination level of 120 million dam/100 sq. cm. The overall weight of BL2 was 72 Ton and its components weighed much as 40 Tons. Transporting the beam line from the TFTR Test Cell to the NSTX-U Test Cell without spreading contamination was a major priority. The components of BL2 were disassembled in order to simplify transportation and be able to decon all parts of the beam line. Decon reduced tenaciously held tritium contamination within the beam line surfaces to approximately two orders of magnitude. Some building structures had to be removed including 9 Ton lintel shield blocks and HVAC ducts to open up space for the beam line transportation. The 40 Ton NB Box was transported from the TFTR Test Cell to the NSTX-U High Bay area by sliding it over air casters and was then moved into the NSTX Test Cell by using the overhead crane to lift it above the 22 ft shield wall. The Lid was then brought in and placed inside the Box followed by other components including the 90" Flange, Magnet, Ion Dump, Exit Spool, TIV, Calorimeter, platforms and Beamline Sources. Three High Voltage Enclosures (HVE) were installed in the NSTX-U Test Cell and connected to the beamline sources using transmission lines. At completion of the 2nd Neutral Beam relocation, a platform was built to provide walkway to and from the 1st Neutral Beam and existing NSTX-U Test Cell Platforms.

Download PPPL-5288 (pdf 1.9 MB 9 pp)
_________________________________________________________________________________________________