{"id":2716,"date":"2017-01-06T17:09:56","date_gmt":"2017-01-06T08:09:56","guid":{"rendered":"http:\/\/fdada.info\/?page_id=2716"},"modified":"2017-01-06T17:10:10","modified_gmt":"2017-01-06T08:10:10","slug":"seq_unit3-en","status":"publish","type":"page","link":"https:\/\/fdada.info\/fdada\/en\/home2\/accident2\/sequences2\/seq_unit3-en\/","title":{"rendered":"Event sequence of Unit 3"},"content":{"rendered":"

Event sequence of Unit 3<\/h2>\r\nCited from NEA\/CSNI\u201cBenchmark Study of the Accident at the Fukushima Daiichi Nuclear Power Plant (BSAF Project) Phase I Summary Report\u201d(2015), p.17.<\/a>

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No<\/th>\r\n Date<\/th>\r\n Time[s]<\/th>\r\n Time[h]<\/th>\r\n Event<\/th>\r\n <\/tr>\r\n <\/thead>\r\n
1<\/td>\r\n 3\/11 14:46:00<\/td>\r\n 0 <\/td>\r\n 0.00 <\/td>\r\n Earthquake<\/td>\r\n <\/tr>\r\n
2<\/td>\r\n 3\/11 14:47:35<\/td>\r\n 95 <\/td>\r\n 0.03 <\/td>\r\n Reactor scram<\/td>\r\n <\/tr>\r\n
3<\/td>\r\n 3\/11 14:48:45<\/td>\r\n 165 <\/td>\r\n 0.05 <\/td>\r\n MSIV closed<\/td>\r\n <\/tr>\r\n
4<\/td>\r\n 3\/11 15:05:00<\/td>\r\n 1,140 <\/td>\r\n 0.32 <\/td>\r\n RCIC manually started<\/td>\r\n <\/tr>\r\n
5<\/td>\r\n 3\/11 15:25:00<\/td>\r\n 2,340 <\/td>\r\n 0.65 <\/td>\r\n RCIC automatically tripped (L-8)<\/td>\r\n <\/tr>\r\n
6<\/td>\r\n 3\/11 15:36:00<\/td>\r\n 3,000 <\/td>\r\n 0.83 <\/td>\r\n Tsunami hit<\/td>\r\n <\/tr>\r\n
7<\/td>\r\n 3\/11 15:38:00<\/td>\r\n 3,120 <\/td>\r\n 0.87 <\/td>\r\n Station black-out<\/td>\r\n <\/tr>\r\n
8<\/td>\r\n 3\/11 16:03:00<\/td>\r\n 4,620 <\/td>\r\n 1.28 <\/td>\r\n RCIC manually started<\/td>\r\n <\/tr>\r\n
9<\/td>\r\n 3\/12 11:36:00<\/td>\r\n 75,000 <\/td>\r\n 20.83 <\/td>\r\n RCIC automatically tripped<\/td>\r\n <\/tr>\r\n
10<\/td>\r\n 3\/12 12:06:00<\/td>\r\n 76,800 <\/td>\r\n 21.33 <\/td>\r\n Alternative S\/C spray by DDFP<\/td>\r\n <\/tr>\r\n
11<\/td>\r\n 3\/12 12:35:00<\/td>\r\n 78,540 <\/td>\r\n 21.82 <\/td>\r\n HPCI automatically started (L-2)<\/td>\r\n <\/tr>\r\n
12<\/td>\r\n 3\/13 02:42:00<\/td>\r\n 129,360 <\/td>\r\n 35.93 <\/td>\r\n HPCI manually stopped<\/td>\r\n <\/tr>\r\n
13<\/td>\r\n 3\/13 03:05:00<\/td>\r\n 130,740 <\/td>\r\n 36.32 <\/td>\r\n Alternative S\/C spray by DDFP was stopped. Completion of switchover to alternative water injection into the reactor reported to MCR<\/td>\r\n <\/tr>\r\n
14<\/td>\r\n 3\/13 05:08:00<\/td>\r\n 138,120 <\/td>\r\n 38.37 <\/td>\r\n Alternative S\/C spray by DDFP started (switched over from the alternative water injection line into the reactor)<\/td>\r\n <\/tr>\r\n
15<\/td>\r\n 3\/13 07:39:00<\/td>\r\n 147,180 <\/td>\r\n 40.88 <\/td>\r\n Alternative D\/W spray by DDFP started (switched over from the alternative S\/C spray)<\/td>\r\n <\/tr>\r\n
16<\/td>\r\n 3\/13 07:43:00<\/td>\r\n 147,420 <\/td>\r\n 40.95 <\/td>\r\n Alternative S\/C spray by DDFP was halted<\/td>\r\n <\/tr>\r\n
17<\/td>\r\n 3\/13 08:40:00 to 09:10:00<\/td>\r\n 150,840 to 152,640<\/td>\r\n 41.9 to 42.4<\/td>\r\n Alternative D\/W spray by DDFP halted. Switched over to alternative water injection line into the reactor.<\/td>\r\n <\/tr>\r\n
18<\/td>\r\n around 3\/13 09:08:00<\/td>\r\n around 152,520<\/td>\r\n around 42.37<\/td>\r\n Reactor depressurized<\/td>\r\n <\/tr>\r\n
19<\/td>\r\n 3\/13 09:20:00<\/td>\r\n 153,240 <\/td>\r\n 42.57 <\/td>\r\n PCV pressure decrease by venting confirmed<\/td>\r\n <\/tr>\r\n
20<\/td>\r\n 3\/13 09:25:00<\/td>\r\n 153,540 <\/td>\r\n 42.65 <\/td>\r\n Freshwater injection started by fire engines<\/td>\r\n <\/tr>\r\n
21<\/td>\r\n 3\/13 11:17:00<\/td>\r\n 160,260 <\/td>\r\n 44.52 <\/td>\r\n Closure of AO-valve of S\/C venting line confirmed due to loss of driving gas pressure<\/td>\r\n <\/tr>\r\n
22<\/td>\r\n 3\/13 12:20:00<\/td>\r\n 164,040 <\/td>\r\n 45.57 <\/td>\r\n Freshwater injection terminated due to water inventory depletion in fire protection pools. Switching over to seawater injection started<\/td>\r\n <\/tr>\r\n
23<\/td>\r\n 3\/13 12:30:00<\/td>\r\n 164,640 <\/td>\r\n 45.73 <\/td>\r\n S\/C vent valve opened for PCV venting<\/td>\r\n <\/tr>\r\n
24<\/td>\r\n 3\/13 13:12:00<\/td>\r\n 167,160 <\/td>\r\n 46.43 <\/td>\r\n Seawater injection line configured and injection started<\/td>\r\n <\/tr>\r\n
25<\/td>\r\n 3\/14 01:10:00<\/td>\r\n 210,240 <\/td>\r\n 58.40 <\/td>\r\n Water injection halted to make up the water source pit<\/td>\r\n <\/tr>\r\n
26<\/td>\r\n 3\/14 03:20:00<\/td>\r\n 218,040 <\/td>\r\n 60.57 <\/td>\r\n Water source pit make up done. Seawater injection resumed<\/td>\r\n <\/tr>\r\n
27<\/td>\r\n 3\/14 05:20:00<\/td>\r\n 225,240 <\/td>\r\n 62.57 <\/td>\r\n Small S\/C vent valve (AO) opening started for PCV venting<\/td>\r\n <\/tr>\r\n
28<\/td>\r\n 3\/14 06:10:00<\/td>\r\n 228,240 <\/td>\r\n 63.40 <\/td>\r\n Small S\/C vent valve (AO) opening started for PCV venting<\/td>\r\n <\/tr>\r\n
29<\/td>\r\n 3\/14 11:01:00<\/td>\r\n 245,700 <\/td>\r\n 68.25 <\/td>\r\n Unit 3 reactor building exploded<\/td>\r\n <\/tr>\r\n
30<\/td>\r\n 3\/14 11:01:00<\/td>\r\n 245,700 <\/td>\r\n 68.25 <\/td>\r\n Seawater injection halted (as consequence of the explosion)<\/td>\r\n <\/tr>\r\n
31<\/td>\r\n 3\/14 15:30:00<\/td>\r\n 261,840 <\/td>\r\n 72.73 <\/td>\r\n Seawater injection resumed<\/td>\r\n <\/tr>\r\n
32<\/td>\r\n 3\/14 19:30:00 to 19:54:00<\/td>\r\n 276,240 to 277,680<\/td>\r\n 76.73 to 77.13<\/td>\r\n Seawater injection halted (fire engines found to have been out-of-service from 30 min to 1 hour before 19:20)<\/td>\r\n <\/tr>\r\n
33<\/td>\r\n 3\/14 21:14:00<\/td>\r\n 282,480 <\/td>\r\n 78.47 <\/td>\r\n Seawater injection halted<\/td>\r\n <\/tr>\r\n
34<\/td>\r\n 3\/15 02:30:00<\/td>\r\n 301,440 <\/td>\r\n 83.73 <\/td>\r\n Seawater injection resumed<\/td>\r\n <\/tr>\r\n
35<\/td>\r\n 3\/15 16:05:00<\/td>\r\n 350,340 <\/td>\r\n 97.32 <\/td>\r\n S\/C vent valve closure assumed for PCV venting<\/td>\r\n <\/tr>\r\n <\/tbody>\r\n<\/table>\r\n\r\n
\r\nback<\/a>\r\n<\/div>\r\n\r\n","protected":false},"excerpt":{"rendered":"Event sequence of Unit 3 Cited from NEA\/CSNI\u201cBenchmark Study of the Accident at the Fukushima Daiichi Nuclear […]","protected":false},"author":1,"featured_media":0,"parent":1129,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"class_list":["post-2716","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/pages\/2716","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/comments?post=2716"}],"version-history":[{"count":1,"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/pages\/2716\/revisions"}],"predecessor-version":[{"id":2717,"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/pages\/2716\/revisions\/2717"}],"up":[{"embeddable":true,"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/pages\/1129"}],"wp:attachment":[{"href":"https:\/\/fdada.info\/fdada\/wp-json\/wp\/v2\/media?parent=2716"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}