Preliminary Design of an Ultra-high Temperature Reactor

Using MHD Power Conversion for Mars Exploration

An Weijian, Song Jian, Xie Jiachun, Hu Gu, Zhao Shouzhi,

Sun Zheng, Wu Yuanyuan

Presented by Xie Jiachun

China Institute of Atomic Energy

4. Conclusion

3. Reactor Design

2. Fuel Consideration

1. Introduction

Contents

Introduction

Item Chemical rocket NTP NEP

Thrust Very high High Low

Isp Low High Very high

Human Mars exploration:

Initial mass

Trip time

Introduction

Thermoelectric Thermionic

Stirling Brayton

Succeeded

or

Promising

Introduction

Schemetic view of MHD reactor system by Ron J. Litchford and Nobuhiro Harada

MHD: a far term technology, >40%, very attractive

Introduction

Parameters values

Thrust , N 100

Isp, s 5000

Operating time, yr 1.5

Table 1

Parameters Values

Thermal power, MW 25

Coolant Helium

Inlet temperature, K 800

Outlet temperature, K 2200

Table 2

Fuel Consideration: Challenges

Ultrahigh temperature

> 2000 K

PWR

SFR

HTGR

……

NTP

Fuel Consideration: Current technology

(U,Zr)C graphite based fuel Cermet fuel

Rover/NERVA GE 710, ANL, and now NCPS

> 2500 K > 2500 K

No more than hundreds of minutes Believed to be much more robust

Reactor Design: Fuel Description

Fuel derived from GE 710 and ANL program

Parameters Values

Active Fuel length(cm) 60.96

Fuel Composition W-60vol%UO2-

6vol%Gd2O3

Coolant Channel number 91

Across Flats(cm) 2.361

Channel Diameter(mm) 0.914

Clad Composition W-25wt%Re

Channel Clad Thickness(mm) 0.204

Outer Clad Thickness(mm) 0.415

Reactor Design: Core Description

Parameters Values

Active Core Height(cm) 60.96

Effective Core Radius(cm) 21.0

Core Height(cm) 71.2

Core Radius(cm) 31.5

Safety Rod Channel Radius(cm) 1.05

Fuel Element Number 246

Filler Element Number 66

Drum Number 16

235U Mass(kg) 254.0

Reactor Mass(kg) 1617.0

Calculation Results: Power Distribution

Calculation Results: Temperature Distribution

Calculation Results: Depletion

Calculation Results: Critical Safety

Submerged in Water

Keff = 0.9652

Submerged in Wet Sand

Keff = 0.9664

Conclusion

Reactor scheme meets the

requirements very well Cermet holds the key

Thank you for your attention