The chapter deals with two topics: 1) evaluation of nuclear thermal hydraulics (NTH) as it derives from the proposed scope; 2) perspectives/proposals for development in the area. Referring to the former topic: NTH implies a universe of knowledge, which, among the other things, is not easy to summarize and is correctly described from different viewpoints. Furthermore, (a) modeling is imperfect; (b) validation is essential; (c) scaling is controversial; (d) uncertainty is a guru-type of matter; (e) applications need proper strategy and consideration of research outcomes, including connections with different technologies. The Best Estimate Plus Uncertainty (BEPU) approach considers those statements and their consequences and fixes the links between NTH on the one side and the Probabilistic Safety Assessment (PSA) and licensing on the other side. Referring to the latter topic, the key outcomes are: a) a reflection needs in relation to expertise and database acquired in the past, i.e. preventing the lost; b) progress in different areas, pursued by several ten-thousands scientists must be followed (i.e. the list of references for the book); c) attempts are proposed to improve fundamental knowledge. Noticeably, strategic investigations are necessary in the areas of turbulence modelling and averaging processes. In this connection most of system codes using relatively large control volumes where interface and wall models appear at the origin of the largest error in calculation results: resolving scaling for physical models, developing and validating physical models for three-dimensional situations and 3-field model shall have the highest priority.
Perspectives in nuclear thermal hydraulics
D’Auria Francesco
Primo
Writing – Original Draft Preparation
;Bestion D.Ultimo
Supervision
2024-01-01
Abstract
The chapter deals with two topics: 1) evaluation of nuclear thermal hydraulics (NTH) as it derives from the proposed scope; 2) perspectives/proposals for development in the area. Referring to the former topic: NTH implies a universe of knowledge, which, among the other things, is not easy to summarize and is correctly described from different viewpoints. Furthermore, (a) modeling is imperfect; (b) validation is essential; (c) scaling is controversial; (d) uncertainty is a guru-type of matter; (e) applications need proper strategy and consideration of research outcomes, including connections with different technologies. The Best Estimate Plus Uncertainty (BEPU) approach considers those statements and their consequences and fixes the links between NTH on the one side and the Probabilistic Safety Assessment (PSA) and licensing on the other side. Referring to the latter topic, the key outcomes are: a) a reflection needs in relation to expertise and database acquired in the past, i.e. preventing the lost; b) progress in different areas, pursued by several ten-thousands scientists must be followed (i.e. the list of references for the book); c) attempts are proposed to improve fundamental knowledge. Noticeably, strategic investigations are necessary in the areas of turbulence modelling and averaging processes. In this connection most of system codes using relatively large control volumes where interface and wall models appear at the origin of the largest error in calculation results: resolving scaling for physical models, developing and validating physical models for three-dimensional situations and 3-field model shall have the highest priority.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
