Study on eutectic melting behavior of control rod materials in core disruptive accidents of sodium-cooled fast reactors, 3; Effect of BC addition on thermophysical properties of austenitic stainless steel in a liquid state

ナトリウム冷却高速炉の炉心損傷事故時の制御棒材の共晶溶融挙動に関する研究,3; BC追加による液状オーステナイトステンレス鋼の熱物性への影響

福山 博之*; 東 英生*; 山野 秀将

Fukuyama, Hiroyuki*; Higashi, Hideo*; Yamano, Hidemasa

溶融混合物316Lステンレス鋼(SS316L)及び制御棒材の熱物性は、ナトリウム冷却高速炉を含む原子力プラントのシビアアクシデント時の炉心崩壊のメカニズムを示すコンピュータ模擬コードの開発に必要である。まず、示差走査熱量測定によりSS316LにBCを追加した際の固相線温度及び液相温度を計測した。溶融316L及びBCを含む溶融316Lの密度,表面張力,垂直分光放射率,比熱容量,熱伝導率の計測には静磁場での電磁浮上技術が用いられた。BC追加による物性への影響の研究は10mass%まで行われた。

Thermophysical properties of molten mixture of 316L stainless steel (SS316L) and control-rod material (BC) are necessary for the development of computer simulation codes that describe core degradation mechanisms during severe accidents in nuclear power plants involving sodium-cooled fast reactors. The effect of BC addition to SS316L on the solidus and liquidus temperatures were first measured by differential scanning calorimetry. An electromagnetic levitation technique performed in a static magnetic field was used to measure the density, surface tension, normal spectral emissivity, specific heat capacity, and thermal conductivity of molten SS316L and SS316L containing BC. The effects of BC addition to SS316L on the thermophysical properties were studied up to 10 mass%.