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Impurity control in near-term tokamak reactors

Description: Several methods for reducing impurity contamination in near-term tokamak reactors by modifying the first-wall surface with a low-Z or low-sputter material are examined. A review of the sputtering data and an assessment of the technological feasibility of various wall modification schemes are presented. The power performance of a near-term tokamak reactor is simulated for various first-wall surface materials, with and without a divertor, in order to evaluate the likely effect of plasma contamination associated with these surface materials.
Date: October 1, 1976
Creator: Stacey, W. M. Jr.; Smith, D. L. & Brooks, J. N.
Partner: UNT Libraries Government Documents Department

Evaluation of the /sup 115/In(n,n)/sup 115m/In reaction for the ENDF/B-V dosimetry file

Description: An evaluation of the /sup 115/In(n,n')/sup 115m/In reaction for the ENDF/B-V Dosimetry File is presented. This evaluation is based entirely on reported experimental differential data. Several data sets were renormalized prior to the evaluation in order to take into account recent adjustments in corresponding standard cross sections and in other nuclear parameters used for derivation of cross sections. The present evaluation is compared with the corresponding ENDF/B-IV evaluation. The value of the spectrum-average cross section for the standard neutron field resulting from thermal-neutron fission of /sup 235/U has been computed for this reaction using cross section values from the present evaluation. This computed cross section compares favorably with the result of a recent evaluation of integral data.
Date: December 1, 1976
Creator: Smith, D. L.
Partner: UNT Libraries Government Documents Department

Remarks concerning the accurate measurement of differential cross sections for threshold reactions used in fast-neutron dosimetry for fission reactors

Description: Some remarks are submitted concerning the measurement of differential cross sections for threshold reactions which are used in fast-neutron dosimetry for fission reactors. The objective is to familiarize the reader with some of the problems associated with these measurements and, in the process, to explain why the existence of large discrepancies in the data sets for many of these reactions is not surprising. Limits to the accuracy which can be expected for these cross sections in the near future--using current technology and available resources--are examined in a general way and recommendations for improving the accuracy of the differential data base for dosimetry reactions are presented.
Date: December 1, 1976
Creator: Smith, D. L.
Partner: UNT Libraries Government Documents Department

Monitoring and measurement of oxygen concentrations in liquid sodium

Description: The measurement of oxygen concentrations in sodium at levels of interest for LMFBR applications is reviewed. Additional data are presented to support the validity of the vanadium-equilibration method as a reference for determination of oxygen concentrations in sodium at levels equal to or less than 15 ppM. Operating experience with electrochemical oxygen meters that have a thoria-yttria electrolyte and a Na--Na/sub 2/O reference electrode is described. Meter lifetimes in excess of one year have generally been achieved for operating temperatures of 352 and 402/sup 0/C, and fairly stable emfs have been observed for periods of several months. 7 fig, 21 references. (auth)
Date: January 1, 1976
Creator: Smith, D. L.
Partner: UNT Libraries Government Documents Department

Influence of sodium on the low-cycle fatigue behavior of types 304 and 316 stainless steel

Description: Fatigue tests in sodium were conducted to investigate the influence of a high-temperature sodium environment on the low-cycle fatigue behavior of Types 304 and 316 stainless steel. The effects of testing in a sodium environment as well as long-term sodium exposure were investigated. The fatigue tests were conducted at 600 and 700/sup 0/C in sodium of controlled purity, viz., approximately 1 ppM oxygen and 0.4 ppM carbon, at a strain rate of 4 x 10/sup -3/s/sup -1/. The fatigue life of annealed Type 316 stainless steel is substantially greater in sodium than when tested in air; however, the fatigue life of annealed Type 304 stainless steel is altered much less when tested in sodium. A 1512-h preexposure to sodium had no significant effect on the fatigue life of Type 316 stainless steel tested in sodium. However, a similar exposure substantially increased the fatigue life of Type 304 stainless steel in sodium. 10 fig. (auth)
Date: January 1, 1976
Creator: Smith, D. L.; Zeman, G. J.; Natesan, K. & Kassner, T. F.
Partner: UNT Libraries Government Documents Department

Tokamak Experimental Power Reactor primary energy conversion system

Description: A primary energy conversion system designed for the ANL Tokamak Experimental Power Reactor consisting of the first wall assembly, the blanket region, the magnet shield and the penetrations for plasma access are herein described.
Date: January 1, 1976
Creator: Stevens, H. C.; Abdou, M. A.; Mattas, R. F.; Maroni, V. A.; Patten, J. S.; Smith, D. L. et al.
Partner: UNT Libraries Government Documents Department