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Title: MFTF-. cap alpha. + T shield design

Abstract

MFTF-..cap alpha..+T is a DT upgrade option of the Tandem Mirror Fusion Test Facility (MFTF-B) to study better plasma performance, and test tritium breeding blankets in an actual fusion reactor environment. The central cell insert, designated DT axicell, has a 2-MW/m/sup 2/ neutron wall loading at the first wall for blanket testing. This upgrade is completely shielded to protect the reactor components, the workers, and the general public from the radiation environment during operation and after shutdown. The shield design for this upgrade is the subject of this paper including the design criteria and the tradeoff studies to reduce the shield cost.

Authors:
Publication Date:
Research Org.:
Argonne National Lab., IL (USA)
OSTI Identifier:
5882134
Report Number(s):
CONF-850310-65
ON: DE85010496
DOE Contract Number:
W-31-109-ENG-38
Resource Type:
Conference
Resource Relation:
Conference: 6. topical meeting on the technology of fusion energy, San Francisco, CA, USA, 3 Mar 1985
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; MFTF DEVICES; SHIELDING; DESIGN; BREEDING; BREEDING BLANKETS; COST; TRITIUM; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; HYDROGEN ISOTOPES; ISOTOPES; LIGHT NUCLEI; MAGNETIC MIRRORS; NUCLEAR FUEL CONVERSION; NUCLEI; ODD-EVEN NUCLEI; OPEN PLASMA DEVICES; RADIOISOTOPES; REACTOR COMPONENTS; THERMONUCLEAR DEVICES; YEARS LIVING RADIOISOTOPES; 700209* - Fusion Power Plant Technology- Component Development & Materials Testing

Citation Formats

Gohar, Y. MFTF-. cap alpha. + T shield design. United States: N. p., 1985. Web.
Gohar, Y. MFTF-. cap alpha. + T shield design. United States.
Gohar, Y. 1985. "MFTF-. cap alpha. + T shield design". United States. doi:. https://www.osti.gov/servlets/purl/5882134.
@article{osti_5882134,
title = {MFTF-. cap alpha. + T shield design},
author = {Gohar, Y.},
abstractNote = {MFTF-..cap alpha..+T is a DT upgrade option of the Tandem Mirror Fusion Test Facility (MFTF-B) to study better plasma performance, and test tritium breeding blankets in an actual fusion reactor environment. The central cell insert, designated DT axicell, has a 2-MW/m/sup 2/ neutron wall loading at the first wall for blanket testing. This upgrade is completely shielded to protect the reactor components, the workers, and the general public from the radiation environment during operation and after shutdown. The shield design for this upgrade is the subject of this paper including the design criteria and the tradeoff studies to reduce the shield cost.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1985,
month = 1
}

Conference:
Other availability
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  • MFTF-..cap alpha..+T is a DT upgrade option of the Tandem Mirror Fusion Test Facility (MFTF-B) to study better plasma performance, and test tritium breeding blankets in an actual fusion reactor environment. The central cell insert, designated DT axicell, has a 2-MW/m/sup 2/ neutron wall loading at the first wall for blanket testing. This upgrade is completely shielded to protect the reactor components, the workers, and the general public from the radiation environment during operation and after shutdown. The shield design for this upgrade is the subject of this paper including the design criteria and the tradeoff studies to reduce themore » shield cost.« less
  • Three separate and distinct vacuum vessel and nuclear shield trade studies were performed in series. The studies are: vacuum topology, nuclear shield location and composition, and water bulk shield location and material selection.
  • Drift pumping in mirrors is a new concept (less than one year old). If it works, compared to charge-exchange pumping, it will simplify the MFTF-..cap alpha..+T interface and possibly reduce the circulating power required. From an engineering standpoint, it has some very demanding requirements in terms of power and bandwidth. This paper describes a design which satisfies these requirements. It also identifies a number of promising alternatives requiring investigation and verification.
  • The conceptual design of the end-plug magnets for MFTF-..cap alpha..+T is described. MFTF-..cap alpha..+ T is a near-term upgrade of MFTF-B, which features new end plugs to improve performance. The Fusion Engineering Design Center has performed the engineering design of MFTF-..cap alpha..+T under the overall direction of Lawrence Livermore National Laboratory. Each end plug consists of two Yin-Yang pairs, each with approx.2.5:1 mirror ratio and approx.5-T peak field on axis; two transition coils; and a recircularizing solenoid. This paper describes the end-plug magnet system functional requirements and presents a conceptual design that meets them. The peak field at the windingsmore » of the end-plug coils is approx.6-T. These coils are designed using the NbTi MFTF-B conductor and cooled by a 4.2K liquid helium bath. All the end-plug magnets are designed to operate in the cryostable mode with adequate quench protection for safety. Shielding requirements are stated and a summary of heat loads is provided. Field and force calculations are discussed. The field on axis is shown to meet the functional requirements. Force resultants are reported in terms of winding running loads and resultant coil forces are also given. The magnet structural support is described. A trade study to determine the optimum end-cell coil internal nuclear shield thickness and the resulting coil size based on minimizing the end-cell life cycle cost is summarized.« less
  • A photon shield capsule made of high density tungsten alloy was designed for a 400 GBq {sup 241}Am/Be ({alpha},n) NIST-traceable source using Monte Carlo calculations. The {sup 241}Am/Be ({alpha},n) source replaces a {sup 239}Pu/Be ({alpha},n) source used in the Los Alamos Neutron Well for dose rate calibrations of portable and fixed neutron rem meters. Potential operator exposure due to {sup 241}Am photon emission (E{sub {gamma}} = 59.5 keV, Y{sub {gamma}} = 0.357 {gamma} d{sup -1}) is a major practical concern in using this type of source. This has been recognized by the International Organization for Standardization (ISO 8529:1989), which recommendsmore » wrapping the source in a 1 mm thick lead shield. However, the optimum photon shield capsule design depends on source construction and other considerations. These considerations include minimizing source spectrum degradation and inelastic gamma production from shielding, structural integrity, toxicity, and cost effectiveness of available materials and construction. Investigations of several materials and combinations using stainless steel, high density tungsten alloy (composed of 90%W, 6% Ni and 4% Cu) and lead with various capsule thicknesses were simulated using the Los Alamos Monte Carlo N-Particle Transport Code. The final design was based on a 2 mm thick capsule using the high density tungsten alloy. This material resulted in a small change in the neutron spectrum accompanied with only a slight increase in inelastic gamma production, and unobservable 59.5 keV photon emissions compared to the bare {sup 241}Am/Be ({alpha},n) source.« less