초록

14 MeV 중성자빔을 구조재료에 조사하였을 때 dpa 손상정도를 MCNPX, SPECTER, PHITS 코드를 이용하여 계산하고 비교 분석하였고, 구조재료에서 생성되는 수소, 헬륨 기체 및 고체원자의 생성량을 도출하였다. 또한 중성자 조사손상 실험을 모의 실험하기 위해서 양성자빔 조사를 통하여 dpa에 따라 나타내는 재료의 특성도 TEM을 이용하여 조사 분석하였다.

( 출처 : 보고서 요약서 5p )

Abstract ▼

Ⅳ. Results
The irradiation damages in pfc materials by 14-MeV neutrons generated from the D-T fusion reactions were simulated. In this study the neutron flux of 3.5×10¹³ neutrons/ cm²·sec from a 0.78 MW/m² neutron wall load of the ITER design base was used. The fl

Ⅳ. Results
The irradiation damages in pfc materials by 14-MeV neutrons generated from the D-T fusion reactions were simulated. In this study the neutron flux of 3.5×10¹³ neutrons/ cm²·sec from a 0.78 MW/m² neutron wall load of the ITER design base was used. The fluence 1.1×10²¹ neutrons/cm² corresponds to a total flux for one-year full power operation. The dpa values of MCNPX/ SPECTER from the irradiation damage of 14-MeV neutron were simulated as 0.6 dpa/fpy for graphite, 4.7 dpa/fpy for Cu and 2.1 dpa/fpy for SS316L. The dpa values of PHITS from the irradiation damage of 14-MeV neutron were simulated as 0.8 dpa/fpy for graphite, 4.6 dpa/fpy for Cu and 2.7 dpa/fpy for SS316L.
Comparing the calculation results of the two codes, the differences for graphite, Cu, and SS316L were 13 %, 9 %, and 13 % respectively.

The hydrogen and helium production rates for pfc were simulated by using the SPECTER code. The hydrogen and helium production rates for graphite during one-year operation were negligible. The hydrogen and helium production rates for copper were 5.5 appm/dpa and 4.5 appm/dpa, respectively. The hydrogen production rate for Fe, Cr, Ni were 40.5 appm/dpa, 37.5 appm/dpa, and 101.7 appm/dpa, respectively. The helium production rate for Fe, Cr, Ni were, 11.1 appm/dpa, 20.3 appm/dpa, and 40.1 appm/dpa, respectively. The hydrogen and helium production rates for SS316L were 40 appm/dpa and 11 appm/dpa, respectively.

The solid elements generated by Fe atoms were Cr and Mn, their production rates were 4.79E-05 and 4.3E-04, respectively. The solid elements generated by the Cr atoms were V and Ti with the production rates of 1.76E-04 and 4.57E-05, respectively. The solid elements generated by Ni atoms were Co and Fe with the production rates of 8.20E-04 and 1.15E-04, respectively.

The phenomena of a 17-MeV proton irradiation were studied because of the neutron source treatments were not available. The PKA spectrum of 17-MeV proton was calculated from Lindhard theory and the PKA spectrum of 14-MeV neutron was simulated by using MCNPX/SPECTER. Similar curves were obtained. For practical experiments, the recoil energy spectrum for proton irradiation was simulated by SRIM code. The Bragg peak by 17-MeV proton irradiation appeared at a 0.64-mm depth and the range is 0.68-mm. For 1016 protons/cm² the dpa values were 5×10^-7 dpa at the SS316 surface and 7×10^-6 dpa at the peak . The SS316L specimens with a 20-mm diameter and an 1-mm thickness were irradiated by the proton beam of KOMAC up to the fluence 10¹⁶ p/cm² at room temperature. These samples were cooled down to a natural background level and analyzed by transmission electron microscopy.

( 출처 : SUMMARY 12p )

목차 Contents

• 표지 ... 1
• 제 출 문 ... 3
• 보고서 요약서 ... 5
• 요 약 문 ... 7
• SUMMARY ... 11
• CONTENTS ... 15
• 목차 ... 17
• 제 1 장 연구개발과제의 개요 ... 19
• 1. 연구개발의 목적 및 필요성 ... 19
• 2. 연구개발의 범위 ... 19
• 제 2 장 국내외 기술개발 현황 ... 20
• 1. 국내 수준 ... 20
• 2. 국내외 연구현황 ... 20
• 제 3 장 연구개발수행 내용 및 결과 ... 21
• 1. 변위손상 원자수(dpa) 전산모사 ... 21
• 가. MCNPX 코드 ... 23
• 나. SPECTER 코드 ... 23
• 다. SRIM 코드 ... 24
• 2. 중성자에 의한 대면재료의 변위손상 원자수 전산모사 ... 24
• 가. 전산모사를 위한 플라즈마 대면재료 사양 ... 24
• 나. MCNPX/SPECTER 코드를 이용한 변위손상 원자수 계산 ... 25
• 다. PHITS 코드를 이용한 변위손상 원자수 계산 ... 31
• 3. 수소 및 헬륨기체 생성 ... 32
• 4. 고체 원자 생성 ... 36
• 5. 유도 방사능 생성 ... 41
• 6. 양성자 조사에 대한 dpa 평가 ... 42
• 가. 변위 단면적 ... 42
• 나. PKA 스펙트럼 ... 43
• 다. SRIM코드를 이용한 양성자의 dpa 계산 ... 44
• 라. 양성자 조사 실험 ... 45
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 49
• 제 5 장 연구개발결과의 활용계획 ... 51
• 제 6 장 참고문헌 ... 52
• 끝페이지 ... 53