台電公司核能電廠因應福島事故之斷然處置措施說明與介紹 王琅琛 2013年1月23日

簡報內容 一.前言 二.緣起 三.斷然處置措施 四.分析結果 五.結論 2

一.前言 9/9 台電首次於大型國際會議(NUTHOS-9)發表斷然處置措施 9/19「兩岸交流研討會」台電公司向大陸介紹斷然處置措施 大陸學者李冠興院士認為台電斷然處置措施實際上是一套保證及時注水的決策程序，值得研究學習。大陸「核安全與放射性汙染防治“十二五”規劃及2020年遠景目標」將斷然處置納入研究建立目標 台電斷然處置措施已發表於國際期刊「Nuclear Engineering and Design 253 (2012) 259-268」 3

二.緣起 福島事故-加長型的電廠全黑事故 長時間喪失ECCS設計資源 運轉參數已不可信 僅剩非正常爐心注水系統(特性-注水壓低) 移動式電源/消防車 廠用水/生水/海水 8

Key lesson learned 3/11 2:46 PM Earthquake Happened (loss of offsite power, start IC/RCIC) 3/11 3:38~41 PM Tsunami attack (loss of AC/DC power) After 3 or 4 days RCIC/HPCI failed Delayed venting, depressurization Finally Core Degradation Hydrogen Explosion To avoid core damage: Short term: Reactor water makeup by non-AC power(IC/RCIC/HPCI )

Key lesson learned Require workable/effective SAM 3/11 2:46 PM Earthquake Happened (loss of offsite power, start IC/RCIC) 3/11 3:38~41 PM Tsunami attack (loss of AC/DC power) After 3 or 4 days RCIC/HPCI failed Delayed venting, depressurization Finally Core Degradation Hydrogen Explosion To avoid core damage: Short term: Reactor water makeup by non-AC power(IC/RCIC/HPCI ) Require workable/effective SAM

Workable SAMG (severe accident management guideline) 3/11 2:46 PM Earthquake Happened (loss of offsite power, start IC/RCIC) 3/11 3:38~41 PM Tsunami attack (loss of AC/DC power) After 3 or 4 days RCIC/HPCI failed Delayed venting, depressurization Finally Core Degradation Hydrogen Explosion Require workable/effective SAM While trying to restore AC/DC power& heat sink, Also: Depressurize by SRV Activate low pressure injection system Containment venting (avoid over-pressure failure) To avoid core damage: Short term: Reactor water makeup by non-AC power(IC/RCIC/HPCI )

Our DIVing procedure: Lineup within 1 hour Start DIVing: Require workable/effective SAM While trying to restore AC/DC power& heat sink, Also: Depressurize by SRV Activate low pressure injection system Containment venting (avoid over-pressure failure) Our DIVing procedure: Lineup within 1 hour Start DIVing: Depressurize by SRV Activate low pressure injection system Containment venting (keep containment in a low pressure)

三.斷然處置措施 “Ultimate Response Guidelines (URG) ” . 正常設計爐心注水系統功能恢復前之應變措施 機組斷然處置措施-DIVing procedure : D : Depressurization緊急洩壓 I : Cooling Water Injection灌水 V : Containment Venting圍阻體通氣 ing : Simultaneously同時進行 15

機組斷然處置措施(各廠已建立程序書並完成演練) 16

Assumptions for Analysis 0秒 發生地震 喪失廠外電源，RCIC啟動 10分 海嘯進來 電廠全黑，控制性降壓開始 1小時 RCIC假設失效 (Start DIVing) 啟動緊急洩壓，洩壓至低壓水可注入之壓力後，開始注水 數小時後 持續操作EOP，維持釋壓閥開啟以利持續注水 (使PCT維持低溫)

成功準則 DIVing高壓轉低壓(HI TO LO)過程 維持電廠完整性確保大眾安全 燃料尖峰護套溫度 < 1500 F 無爐心熔毀 無氫氣產生 無須進行疏散 維持電廠完整性確保大眾安全 18

四.分析結果(核一廠) 19 19

壓力與注水流量變化圖(C)

壓力與水位變化圖(C)

水位與PCT變化圖(C)

Raw Water Flow PCT(℉) 450 gpm 809.20 400 gpm 1404.01 350 gpm 1550.35 PCT vs. Raw Water Flow

~ Effect of RCIC Available Time ~ Raw Water Flow PCT (℉) 4HR 8HR 400 gpm 756.909 - 350 gpm 1250.52 587.33 300 gpm 1566.75 1323.1 250 gpm Exceed 1520.4 4 hr 1 hr 8 hr 255 gpm 310 gpm 370 gpm PCT vs. Raw Water Flow

Diff. Raw Water Flow Rate after PCT vs. PCT Chinshan Raw Water Pool Capability : 250 gpm Diff. Raw Water Flow Rate after PCT vs. PCT

四.分析結果(核二廠) 26 26

壓力與注水流量變化圖(K)

壓力與水位變化圖(K)

水位與PCT變化圖(K)

PCT vs. Raw Water Flow Raw Water Flow PCT(℉) 800 1055.29 750 1092.67 700 1201.25 650 1466.90 600 1803.02 1500 F 645 gpm PCT vs. Raw Water Flow

~ Effect of RCIC Available Time ~ Raw Water Flow PCT (℉) 4HR 8HR 600 920.387 761.928 550 1356.97 - 500 1760.15 1322.93 450 exceed 1642.97 1 hr 4 hr 8 hr 475 gpm 530 gpm 645 gpm PCT vs. Raw Water Flow

四.分析結果(核四廠) 32 32

壓力與注水流量變化圖(L)

壓力與水位變化圖(L)

水位與PCT變化圖(L)

Reactor Injection Flow Rate (gpm) Analysis Condition Required Minimum Reactor Injection Flow Rate (gpm) Base Case 1974 4 Hours RCIC Available Time 1483 8 Hours RCIC Available Time 1335 Raw Water Injection at Reactor Upper Plenum 801

四.分析結果(核三廠) 37 37

蒸汽產生器壓力

蒸汽產生器水位 39

一次側自然循環流量 40

Emptiness of Accumulator by RCP Seal Leakage 41

Descending of Reactor Water Level by RCP Seal Leakage 42

Termination of RCS Natural Circulation Flow by RCP Seal Leakage 43

Effect of Accumulator Isolation on Reactor Water Level Descending RCP 軸封洩漏分析 Effect of Accumulator Isolation on Reactor Water Level Descending 44

Effect of Accumulator Isolation on PCT Ascending RCP 軸封洩漏分析 Effect of Accumulator Isolation on PCT Ascending 45

五.結論 應付福島此類加長型的電廠全黑事故， 「機組斷然處置措施」主要操作為: (1)啟動DIVing動作之前，爐心或蒸汽產生器設法先行適度降壓。 (2)啟動DIVing動作時，緊急洩壓將已列置妥當之非正常爐心注水(消防水)迅速灌入爐心或蒸汽產生器同時執行圍阻體通氣至大氣，避免圍阻體內壓過高造成水無法灌入。 (3) DIVing動作順利完成後，EOP後續之操作應避免爐心或蒸汽產生器壓力再次上升而阻礙消防水持續灌入。

五.結論(續) 台電公司各運轉中核能電廠已依「機組斷然處置措施」之理念，精進現有操作程序書及完成人員訓練，並利用夜間實地模擬全黑測試及在多次緊急計畫演習中演練，證實一旦核能電廠遭遇超過預期的複合式災害， 「機組斷然處置措施」仍然可以確保核能安全，不會讓輻射有外洩的機會。 另因應日本福島事故，台電公司也比照國際作法進行核安總體檢，以深度防禦觀念，執行各項強化措施，提升各電廠的防災能力。

Thanks for your attention 謝謝注意 洩洩注逸 洩洩注溢 48

內容(緊急洩壓) 核一廠－4260-3600=660 seconds 核二廠—4200-3600=600 seconds

PCT與注水流量關係圖. Base Case. :. 1974 gpm (緊急洩壓開啟 8 只 SRVs; 生水注入降流區) PCT與注水流量關係圖 Base Case : 1974 gpm (緊急洩壓開啟 8 只 SRVs; 生水注入降流區) SRVx16 Case : 1497 gpm (緊急洩壓開啟 16 只 SRVs; 生水注入降流區)