Safety classifications for the fusion DEMO plant of Korea

Abstract

Regulatory requirements and industrial codes and standards are to be compulsory top-tier prerequisites for the design and construction of a power plant with nuclear technologies. As it will take considerable time and substantial amounts of investment to develop that for the fusion power plants, design studies on a fusion DEMO plant will be carried out in parallel with developing its regulatory requirements and codes and standards. To overcome this dilemma, a tentative set of general design criteria and classification criteria that are to be applicable for the design studies of the fusion DEMO plant of Korea (DEMO Plant) are proposed with the vacuum vessel pressure boundary that corresponds to the Reactor Coolant Pressure Boundary of the nuclear power plant. To determine the tentative set, the radiation release to the environment and consequences of the postulated events in DEMO Plant are analyzed with rough approximation assuming the inherent safety of a fusion DEMO reactor. The classification criteria of the tentative set include safety class, electrical class, quality group and seismic category for the components, structures and systems of DEMO Plant. Use of ASME Section III for the design study of DEMO Plant is also proposed to make the best use of the commonalities between DEMO Plant and existing nuclear power plant. A. Overview of the DEMO Program of Korea The ftrst phase of the fusion DEMO program of Korea (DEMO Program) is a preparatory program, from 2009 through 2011, and is mainly for deftning the life cycle and developing the strategic plans for the program. In accordance with the strategic plans, the second phase of DEMO Program is to be a R&D program that is to put focus on developing engineering and construction technologies, rather than carrying out scientiftc researches, to expedite realization of fusion energy in the bottom half of 2030s [1]: It is to rely on the scientiftc outcomes of and lessons learned from KST AR, ITER, 978-1-4577-0668-4111/$26.00

An exploratory study on the gaps and pathways to the Korean fusion DEMO

“…-Safety analysis on K-DEMO reactor in accordance with the current methodologies used for the design of NPPs was carried out and the needs for the engineered safety features were discovered [10]; -Analysis of the source terms and radiological consequences, in accordance with the results of the safety analysis and also with the technologies and databases of NPPs, were carried out and it was discovered that the tritium behaviors will be dominant, but unresolved, issues for the design of K-DEMO reactor [11]; -The regulatory requirements and C&S applicable for the development of K-DEMO reactor have been studied and they most likely will be developed through the iterative processes of designing, manufacturing, testing, constructing, and even operation of K-DEMO reactor [11]; -The life cycle management of K-DEMO program was reviewed and needs for the scenario based risk management, cost estimation, and time management were identified.…”

“…Tritium is expected to be the major contributor to the source-terms of a fusion reactor [15] and K-DEMO plant as well [11]. The studies on tritium inventories and behaviors were started as an in-kind procurement of ITER.…”

“…With the exploratory studies on the safety and licensing of K-DEMO plant [11], the desired status of safety and licensing will be as follows:…”

“…8 the top-tier requirements, including regulatory requirements and C&S for MFE, will be developed in parallel with design, fabrication, testing, construction, and operation of K-DEMO itself: As K-DEMO will be a first-of-a-kind, validation tests for the top-tier requirements will be carried out in K-DEMO through iterative processes as it is a first-of-a-kind [11].…”