大型ナトリウム冷却高速炉（JSFR）の自然循環崩壊熱除去に関する試験研究

摘要

Fully natural circulation system is adopted in a decay heat removal system (DHRS) of the designs of Japan Sodium Cooled Fast Reactor (JSFR). Several investigations of experiments and simulation methods on this DHRS were performed. Water experiments were carried out for the primary heat transportation system including a reactor vessel and heat exchangers of DHRS using a 1/10 model. As for the DHRS loop, sodium experiments were carried out, especially for a heat exchanger installed in an Intermediate Heat Exchanger (IHX). Here, several results of the sodium experiments were described. Transient characteristics during the start up in the air system of the air cooler, secondary loop of DHRS, and the primary loop were examined by the sodium experiments. Smooth increases of natural circulation flow rates in all systems of air and sodium were confirmed. Verifications of numerical simulation methods are planned based on the water and sodium experiments in this investigation plan.%JSFRの自然循環崩壊熱除去システムについて，水rnおよびナトリウム試験を実施した．ナトリウム試験rnでは，崩壊熱除去系の空気系，2次側ナトリウムルrnープ，1次系の自然循環の起動過程を把握した．空rn気側入口ベーンを開けることで，全系統の自然循環rnがスムーズに立ち上がることを確認した．rn本報告は，特別会計に関する法律（エネルギー対rn策特別会計）に基づく文部科学省からの受託事業とrnして，三菱FBRシステムズ㈱が実施した平成20年rn度「過渡時の自然循環による除熱特性解析手法の開rn発」の成果である．尚，本報のナトリウム試験は三rn菱FBRシステムズ㈱から委託を受けて原子力機構rnが実施したものである．