Experimental study on gas entrainment due to non-stationary vortex in a sodium cooled fast reactor; Comparison of onset conditions between sodium and water

ナトリウム冷却高速炉における非定常渦によるガス巻込みに関する実験研究; ナトリウムと水の初生条件の比較

木村 暢之; 江連 俊樹 ; 宮越 博幸; 上出 英樹 ; 福田 武司*

Kimura, Nobuyuki; Ezure, Toshiki; Miyakoshi, Hiroyuki; Kamide, Hideki; Fukuda, Takeshi*

ナトリウム冷却高速炉の炉上部プレナムの自由液面で発生が懸念されているガス巻込み現象に関して、同一形状の水試験/ナトリウム試験を実施し、発生条件に対する流体物性値の影響を確認した。その結果、水に比べてナトリウムの方が、わずかにガス巻込みを発生しにくいことがわかった。

In an innovative sodium cooled fast reactor, a compact reactor vessel (R/V) with increased sodium flow velocity was designed to reduce the construction cost. One of the thermal hydraulic problems in this design is gas entrainment at the free surface in the R/V. Sodium experiments were carried out to clarify the onset criteria of the gas entrainment due to a free surface vortex. Water experiments using a test section in which geometry is the same as that in the sodium tests were also performed. The gas entrainment in water slightly tended to take place in comparison with that in sodium under low velocity conditions.