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Nuclear data for fusion: a view from two meetings
ELSEVIER
Fusion Engineering and Design 28 (1995) 446-448
Fusion Engineer!ng and Des,gn
Nuclear data for fusion: a view from two meetings Frederick M. Mann a, Edward T. Cheng b aWestinghouse Hanford Company, PO Box 1970 MSIN H0-36, Richland, WA 99352, USA bTSI Research Inc, 225 Stevens Avenue, Solana Beach, CA 92075, USA
Abstract
Recently two meetings dealing with nuclear data have been held which gave major attention to nuclear data needs and developments of fusion. A brief overview of these meetings is given.
1. Introduction
A major focus of nuclear data activities around the world is the application to fusion energy. Recently two meetings, The International Workshop on Nuclear Data for Fusion Reactor Technology and The International Conference on Nuclear Data for Science and Technology, have occurred where major attention was paid to the need, the status, and the future of nuclear data for fusion technology. Although progress is being made, there are still major uncertainties in fusion technology that need better nuclear data.
2. Del Mar Workshop
The first-ever International Workshop on Nuclear Data for Fusion Reactor Technology was held May of 1993, in Del Mar, California, USA. The location, near the International Thermonuclear Experimental Reactor (ITER) San Diego co-center, was selected to maximize contact with the ITER staff.
The objective of the workshop was to gather the leading international experts to determine the adequacy of nuclear data for the design of ITER. As this was a workshop, the 82 experimentalists, evaluators, designers, and other users of nuclear data spent their time discussing nuclear data needs, status, and plans. The workshop greatly benefited from the contributions from members of the ITER team. The workshop was divided into various subgroups: 1. Nuclear data needs - - Plenary Session 2. Measurements a. Measurement facilities b. Status of International Measurements Program c. International data measurements 3. Evaluations a. Status of nuclear data evaluations for fusion applications b. Fusion evaluation Nuclear Data Library (FENDL) activities e. International cooperation in data evaluations d. Nuclear models/theory/evaluation techniques
0920-3796•95/$09.50 © 1995 Elsevier Science S.A. All rights reserved SSDI 0920-3796(94) 00235-5
F.M. Mann, E.T. Cheng / Fusion Engineering and Design 28 (1995) 446-448
4. Validation of libraries a. Interface between experiment and calculation b. Activation evaluations/calculations c. Integral measurements and benchmarking nuclear data 5. Validation of workshop recommendations Major deficiencies were found in the evaluations of various materials considered for applications of ITER. Plans were outlined to correct the deficiencies. More general concerns were also discussed: A. Communication must be improved between nuclear data generators and processors and the people using the nuclear data such as reactor physicists and safety analysts. B. There are cases where data are said to be known to 20%, yet evaluations can differ by factors of two. Uncertainty bands are extremely important, although they may be difficult to determine. An example is SSNi(n,p)5~Co. The workshop learned that the uncertainties in nuclear data lead to uncertainties in nuclear responses which will lead to concerns in: A. Safety (due to uncertainties in radionuclide production). B. Operations (due to uncertainties in the time periods necessary to allow entry into the torus). C. Waste management (due to uncertainties in radionuclide production). D. Heating in critical components such as the superconducting magnets. E. Determination of shielding thicknesses. Experimental facilities were found to be insufficiently supported and certain important capabilities to meet data needs for fusion development have been lost in recent years. Others are expected to be closed in the near future. There appears to be no organized effort to coordinate facilities internationally so that fusion nuclear data needs can be met in the future. More reliance is being placed on nuclear models in the preparation of evaluated nuclear data libraries. Modeling approaches have advanced significantly in recent years and much more is known about the accuracy with which certain nuclear data can be predicted. Still, further model development is essential to providing data with small uncertainties, in particular for reactions that cannot be measured directly such as on radioactive nuclei for which there are no target materials available. A full report on the workshop [1] is available from the Workshop Chairman, Dr. E. Cheng. the next meeting will occur in September of 1995. Dr. Cheng and Dr. C. Dunford of the Nuclear Data Section of the Interna-
447
tional Atomic Energy Agency (IAEA) will coordinate the next meeting with the ITER project.
3. Gatlinburg Conference The International Conference on Nuclear Data for Science and Technology: Nuclear Data for the Twentyfirst Century was held in May, 1994 in Gatlinburg, Tennessee, USA. This meeting is the latest meeting in a series that dates from the 1960s in three-year intervals. Over 250 nuclear data experts in various fields (fusion, fission power, defense needs, medicine, space, and others) presented 305 papers. Some progress has been made in the year since the Del Mar Workshop. The GEEL accelerator, the source of much of the resonance parameters for the structural materials, is now ensured funding. Talks [2] on the outstanding University of Japan Atomic Energy Research Institute-California Los Angeles series of measurements were presented as were talks on structural materials performed in Germany [3] and Japan [4]. On the theoretical side, M. Chadwick of Lawrence Livermore National Laboratory is now able to deduce the angular distribution systematic of C. Kalbach [5]. The F E N D L files selected under the auspices of the Nuclear Data Section of the IAEA have been processed by Dr. R. MacFarlane of the Los Alamos National Laboratory (LANL) (general purpose files) and by Dr. F. Mann of Westinghouse Hanford Company (activation file). The coordinated research programs of the IAEA on helium production and on long-lived activation cross sections reported progress in measurements and calculations [6]. Other progress on activation libraries include the validation efforts at L A N L [7] and the use of uncertainty data in actual activation calculations by the Energy Center of the Netherlands [8]. More obvious in this conference than in previous meetings in the series a r e international teams that are now tackling problems in nuclear data important for fusion. Proceedings of the meeting will be published in a special issue of Nuclear Science and Engineering. The next meeting will be in 1997 with Russia having submitted a bid.
4. Conclusions The Del Mar Workshop demonstrated the importance and benefit of increasing the communication be-
448
F.M. Mann, E.T. Cheng / Fusion Engineering and Design 28 (1995) 446-448
tween the designers of fusion devices and the developers of nuclear data. The Gatlinburg Conference demonstrated the importance of international teams. By building on both trends, the nuclear data community can better meet the needs of the fusion designers.
[4]
[5]
References [1] E. Cheng, F. Mann, D. Ruane, and G. Howell, International Workshop on Nuclear Data for Fusion Reactor Technology, Del Mar, California, 1993. Available from TSI Research corp, 225 Stevens Avenue, Solona Beach, California, 92075, USA. [2] Y. Ikeda and A. Kumar, Nuclear heating measurements with a micro-calorimeter and KERMA data testing, to be published in Nucl. Sci. Eng. See also papers in this conference. [3] D. Schmidt, W. Mannhart and R. Nolte, Neutron scat-
[6]
[7]
[8]
tering cross sections of iron. to be published in Nucl. Sci. Eng. M. Baba, N. Ito, I. Matsuyama, S. Matsuyama, N. Hirakawa, S. Chiba, T. Fukahori, M. Mizumoto, K. Hasegawa and S. Meigo, Measurement of double-differential (n,c0 cross sections of Fe, Ni, Cu, and 50Cr for 4.5-14.1 MeV neutrons, to be published in Nucl. Sci. Eng. P.E. Hodgson and M.B. Chadwick, The Feshbach-Kerman-Koonin multistep reaction theory and its applications to data evaluation, to be published in Nucl. Sci. Eng. D. Smith, M. Chadwick, J. Csikai, A. Paschenko and H. Vonach, Investigation of the generation of several longlived radionuclides of fusion reactor technology, to be published in Nucl. Sci. Eng. D.W. Muir and W.B. Wilson, Validation of a large activation cross-section library, to be published in Nucl. Sci. Eng. R.A. Forrest, Nuclear data for fusion reactor calculations, to be published in Nucl. Sci. Eng.
Fusion Engineering and Design 28 (1995) 446-448
Fusion Engineer!ng and Des,gn
Nuclear data for fusion: a view from two meetings Frederick M. Mann a, Edward T. Cheng b aWestinghouse Hanford Company, PO Box 1970 MSIN H0-36, Richland, WA 99352, USA bTSI Research Inc, 225 Stevens Avenue, Solana Beach, CA 92075, USA
Abstract
Recently two meetings dealing with nuclear data have been held which gave major attention to nuclear data needs and developments of fusion. A brief overview of these meetings is given.
1. Introduction
A major focus of nuclear data activities around the world is the application to fusion energy. Recently two meetings, The International Workshop on Nuclear Data for Fusion Reactor Technology and The International Conference on Nuclear Data for Science and Technology, have occurred where major attention was paid to the need, the status, and the future of nuclear data for fusion technology. Although progress is being made, there are still major uncertainties in fusion technology that need better nuclear data.
2. Del Mar Workshop
The first-ever International Workshop on Nuclear Data for Fusion Reactor Technology was held May of 1993, in Del Mar, California, USA. The location, near the International Thermonuclear Experimental Reactor (ITER) San Diego co-center, was selected to maximize contact with the ITER staff.
The objective of the workshop was to gather the leading international experts to determine the adequacy of nuclear data for the design of ITER. As this was a workshop, the 82 experimentalists, evaluators, designers, and other users of nuclear data spent their time discussing nuclear data needs, status, and plans. The workshop greatly benefited from the contributions from members of the ITER team. The workshop was divided into various subgroups: 1. Nuclear data needs - - Plenary Session 2. Measurements a. Measurement facilities b. Status of International Measurements Program c. International data measurements 3. Evaluations a. Status of nuclear data evaluations for fusion applications b. Fusion evaluation Nuclear Data Library (FENDL) activities e. International cooperation in data evaluations d. Nuclear models/theory/evaluation techniques
0920-3796•95/$09.50 © 1995 Elsevier Science S.A. All rights reserved SSDI 0920-3796(94) 00235-5
F.M. Mann, E.T. Cheng / Fusion Engineering and Design 28 (1995) 446-448
4. Validation of libraries a. Interface between experiment and calculation b. Activation evaluations/calculations c. Integral measurements and benchmarking nuclear data 5. Validation of workshop recommendations Major deficiencies were found in the evaluations of various materials considered for applications of ITER. Plans were outlined to correct the deficiencies. More general concerns were also discussed: A. Communication must be improved between nuclear data generators and processors and the people using the nuclear data such as reactor physicists and safety analysts. B. There are cases where data are said to be known to 20%, yet evaluations can differ by factors of two. Uncertainty bands are extremely important, although they may be difficult to determine. An example is SSNi(n,p)5~Co. The workshop learned that the uncertainties in nuclear data lead to uncertainties in nuclear responses which will lead to concerns in: A. Safety (due to uncertainties in radionuclide production). B. Operations (due to uncertainties in the time periods necessary to allow entry into the torus). C. Waste management (due to uncertainties in radionuclide production). D. Heating in critical components such as the superconducting magnets. E. Determination of shielding thicknesses. Experimental facilities were found to be insufficiently supported and certain important capabilities to meet data needs for fusion development have been lost in recent years. Others are expected to be closed in the near future. There appears to be no organized effort to coordinate facilities internationally so that fusion nuclear data needs can be met in the future. More reliance is being placed on nuclear models in the preparation of evaluated nuclear data libraries. Modeling approaches have advanced significantly in recent years and much more is known about the accuracy with which certain nuclear data can be predicted. Still, further model development is essential to providing data with small uncertainties, in particular for reactions that cannot be measured directly such as on radioactive nuclei for which there are no target materials available. A full report on the workshop [1] is available from the Workshop Chairman, Dr. E. Cheng. the next meeting will occur in September of 1995. Dr. Cheng and Dr. C. Dunford of the Nuclear Data Section of the Interna-
447
tional Atomic Energy Agency (IAEA) will coordinate the next meeting with the ITER project.
3. Gatlinburg Conference The International Conference on Nuclear Data for Science and Technology: Nuclear Data for the Twentyfirst Century was held in May, 1994 in Gatlinburg, Tennessee, USA. This meeting is the latest meeting in a series that dates from the 1960s in three-year intervals. Over 250 nuclear data experts in various fields (fusion, fission power, defense needs, medicine, space, and others) presented 305 papers. Some progress has been made in the year since the Del Mar Workshop. The GEEL accelerator, the source of much of the resonance parameters for the structural materials, is now ensured funding. Talks [2] on the outstanding University of Japan Atomic Energy Research Institute-California Los Angeles series of measurements were presented as were talks on structural materials performed in Germany [3] and Japan [4]. On the theoretical side, M. Chadwick of Lawrence Livermore National Laboratory is now able to deduce the angular distribution systematic of C. Kalbach [5]. The F E N D L files selected under the auspices of the Nuclear Data Section of the IAEA have been processed by Dr. R. MacFarlane of the Los Alamos National Laboratory (LANL) (general purpose files) and by Dr. F. Mann of Westinghouse Hanford Company (activation file). The coordinated research programs of the IAEA on helium production and on long-lived activation cross sections reported progress in measurements and calculations [6]. Other progress on activation libraries include the validation efforts at L A N L [7] and the use of uncertainty data in actual activation calculations by the Energy Center of the Netherlands [8]. More obvious in this conference than in previous meetings in the series a r e international teams that are now tackling problems in nuclear data important for fusion. Proceedings of the meeting will be published in a special issue of Nuclear Science and Engineering. The next meeting will be in 1997 with Russia having submitted a bid.
4. Conclusions The Del Mar Workshop demonstrated the importance and benefit of increasing the communication be-
448
F.M. Mann, E.T. Cheng / Fusion Engineering and Design 28 (1995) 446-448
tween the designers of fusion devices and the developers of nuclear data. The Gatlinburg Conference demonstrated the importance of international teams. By building on both trends, the nuclear data community can better meet the needs of the fusion designers.
[4]
[5]
References [1] E. Cheng, F. Mann, D. Ruane, and G. Howell, International Workshop on Nuclear Data for Fusion Reactor Technology, Del Mar, California, 1993. Available from TSI Research corp, 225 Stevens Avenue, Solona Beach, California, 92075, USA. [2] Y. Ikeda and A. Kumar, Nuclear heating measurements with a micro-calorimeter and KERMA data testing, to be published in Nucl. Sci. Eng. See also papers in this conference. [3] D. Schmidt, W. Mannhart and R. Nolte, Neutron scat-
[6]
[7]
[8]
tering cross sections of iron. to be published in Nucl. Sci. Eng. M. Baba, N. Ito, I. Matsuyama, S. Matsuyama, N. Hirakawa, S. Chiba, T. Fukahori, M. Mizumoto, K. Hasegawa and S. Meigo, Measurement of double-differential (n,c0 cross sections of Fe, Ni, Cu, and 50Cr for 4.5-14.1 MeV neutrons, to be published in Nucl. Sci. Eng. P.E. Hodgson and M.B. Chadwick, The Feshbach-Kerman-Koonin multistep reaction theory and its applications to data evaluation, to be published in Nucl. Sci. Eng. D. Smith, M. Chadwick, J. Csikai, A. Paschenko and H. Vonach, Investigation of the generation of several longlived radionuclides of fusion reactor technology, to be published in Nucl. Sci. Eng. D.W. Muir and W.B. Wilson, Validation of a large activation cross-section library, to be published in Nucl. Sci. Eng. R.A. Forrest, Nuclear data for fusion reactor calculations, to be published in Nucl. Sci. Eng.