05pD17P
炉心プラズマと炉内構造物の過渡応答解析コードに基づく安全性研究
Safety Research based on Transient Response Code Coupled with
Core Plasma and Plasma Facing Components筒井俊樹1),東郷訓1),伊庭野健造1),小川雄一1)
T.Tsutusi1), S.Togo1), K.Ibano1), Y.Ogawa1)
1)東京大学 新領域科学研究科
1) Graduated school of Frontier Sciences, the University of Tokyo
excess output). In fig.1, the top is the data of output(green) and fueling rate (red), the second is the dataof surface temperature of divertor (red) andevaporation rate of surface (green), the third is dataof ion (green) and electron (red) temperature , thebottom is the data of ion (green), impurity (blue)and electron (red) density. Excess output heats
PFCs and surface temperature rises. The impurities
from PFCs rise and go through plasma and cool
plasma, and then plasma shuts down.
Now, to improve plasma model between the coreand edge plasmas, zero-dimensional plasma model
is subtended three regions, CORE, SOL andDIVERTORregion.
CORE
model
is
zero-dimensional, as well, and in SOL andDIVERTOR model is 2-point model (2) isintroduced. CORE model give the flux across theseparatrix to solve SOL/DIV 2-point model. In thismodel, we expect dividing and integrating featuresof core and edge plasma.

Introduction
A safety analysis code RAILS has been developed
to analyze in-Vessel anomaly events, for example,
the plasma in LOCA (loss of coolant accident)
event, loss of plasma control, excess energy output
event and so on. This code evaluates the time
evolution of plasma parameters and temperature
distribution of plasma facing components (PFCs) inthese anomaly events. This code goes by SAFALY
code that used safety analysis of ITER, integrating azero dimensional plasma model and one
dimensional thermal analysis of in-vessel
components (1).
RAILS code is firstly aim to research “passive”
safety analysis with no active controls. It will give
prospects of how much damage is in worst case,timescales and relative priority in various anomaly
events. This research will also contribute toconsider a necessity of- “active” safety functions- ,for example, plasma control for soft landing andsafety interlocks in reactor.
Numerical models
RAILS code is composing of the plasma transportmodel and the thermal analysis model of PFCs. In
the plasma model, particle balance and energybalance are calculated; the set of main parameters
includes fuel density, alpha density, impuritydensity, electron density, ion temperature andelectron temperature. Thermal analysis model is
one-dimensional and the PFCs are divided into
several regions. These models are interactively
combined by heat flux to PFCs and impurity source
to core plasma. Plasma model decides the boundary
conditions of thermal model. PFCs become
impurity sources, surface temperatures decide theamount of impurity emission, and some of them go
into plasma.
In previous research, we composed code
integrating a zero dimensional plasma model and
one dimensional thermal model (wall material isassumed Carbon) and simulated some anomaly
event (see Fig.1: irregular pellet injection andFig.1 development of excess output scenario

Reference(1) HONDA, T., et al.,”Development of Time
Dependent Safety Analysis Code for Plasma
Anomaly Events in Fusion Reactors”, J. Nucl. Sci.
Tech. 34(1997)(2) R. Hiwatari., et al.,” Simple Core-SOL-Divertor
model and its application to operational apace ofHT-7U”, Journal of Nuclear Materials, 337-339(2005)

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