Thermal-hydraulics is one of the fundamental disciplines for the design and the operation of water cooled nuclear reactors. Achieving large core power densities requires deep understanding of thermal-hydraulics. Thermal hydraulics became one of the main nuclear safety disciplines when postulated accidents like the Loss-of-Coolant Accident (LOCA) and other thermal-hydraulic transients were identified as the dominant safety concern for LWRs. As full-scale experimentation was not feasible in most situations, significant computational developments had to be undertaken to be able to properly simulate such transients, as needed for the safety case of these reactors. Numerous national and international experimental programmes provided the data necessary for understanding the phenomena and simulating them. The CSNI has always considered with great attention the issue of thermal-hydraulic code validation as well as the experimental database needed for such validation. An overview of the large number of separate-effect and integral test programmes that have been carried out in the past is given in previous SESAR reports.1 2 3 4 The results from these programmes provide a sound basis for model validation of traditional system codes, whereas they are insufficient for multi-dimensional and, especially, for CFD codes. Wide research programs in thermal-hydraulics have been carried out in the period from 70’s to 90’s and contributed to confirm the safety of existing reactors. Once the objectives were achieved, interest and financing towards the related activities dropped down. Several large scale facilities and even laboratories all over the world have been closed or largely reduced their activities. On the one hand, the availability of data from those research programs for future use became difficult or questionable; on the other hand, the expertise of experimentalists leading those programs appears to be lost.
Issues and facilities unique to the nuclear industry - Thermal-hydraulics
F. D’Auria
Conceptualization
;
2019-01-01
Abstract
Thermal-hydraulics is one of the fundamental disciplines for the design and the operation of water cooled nuclear reactors. Achieving large core power densities requires deep understanding of thermal-hydraulics. Thermal hydraulics became one of the main nuclear safety disciplines when postulated accidents like the Loss-of-Coolant Accident (LOCA) and other thermal-hydraulic transients were identified as the dominant safety concern for LWRs. As full-scale experimentation was not feasible in most situations, significant computational developments had to be undertaken to be able to properly simulate such transients, as needed for the safety case of these reactors. Numerous national and international experimental programmes provided the data necessary for understanding the phenomena and simulating them. The CSNI has always considered with great attention the issue of thermal-hydraulic code validation as well as the experimental database needed for such validation. An overview of the large number of separate-effect and integral test programmes that have been carried out in the past is given in previous SESAR reports.1 2 3 4 The results from these programmes provide a sound basis for model validation of traditional system codes, whereas they are insufficient for multi-dimensional and, especially, for CFD codes. Wide research programs in thermal-hydraulics have been carried out in the period from 70’s to 90’s and contributed to confirm the safety of existing reactors. Once the objectives were achieved, interest and financing towards the related activities dropped down. Several large scale facilities and even laboratories all over the world have been closed or largely reduced their activities. On the one hand, the availability of data from those research programs for future use became difficult or questionable; on the other hand, the expertise of experimentalists leading those programs appears to be lost.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
