Real-time operations, regulatory movement and commercial impact—translated into decision-ready intelligence.
Kashiwazaki-Kariwa · Photo: 皓月旗 / CC BY-SA 4.0
New information ranked and translated into its decision context.
Validated from complete nuclear records in OCCTO's unit-level publication.
This is the latest complete validated national day. Later incomplete publications are rejected rather than displayed as national totals.
Mitsubishi Heavy Industries raised its fiscal-2026 nuclear order forecast to ¥600 billion from ¥450 billion and its nuclear revenue forecast to ¥550 billion from ¥400 billion. The company attributes the order revision partly to increased fuel-cycle work and says it currently expects about ¥100 billion of production-capacity investment from fiscal 2027, including renewal of large processing equipment with new nuclear construction in view.
The disclosure is a primary-source signal of stronger near-term demand across Japan's nuclear and fuel-cycle supply chain and a concrete commitment to expand heavy-manufacturing capacity for future projects. The ¥100 billion figure is a forward investment plan, not completed spending or evidence that a new reactor project has been approved.
Kyushu Electric applied to the NRA to amend the approved long-term facility-management plans for Sendai 1 and 2 after deciding to add a new type of electrical penetration. The operator says its additional evaluation found no soundness problem at the 60-year operating point and no additional maintenance activity required for the new type.
The filing updates the regulatory ageing-management basis for two operating 890 MW reactors. It is an application, not an approval: the change remains subject to NRA review and does not alter either unit's current operating classification or establish completion of the regulatory process.
The NRA's 29 October dated page classifies 13 of Japan's 33 existing commercial reactors as operating and 20 as suspended. Compared with the retained 20 October snapshot, Onagawa 2 and Genkai 3 moved from suspended to operating; the other unit classifications are unchanged.
The dated regulatory snapshot adds 2,005 MW of unit membership to the NRA operating category and updates the Fleet Pulse and fleet register. It is not presented as a live output feed: current operator observations and OCCTO measured generation remain separately labelled.
Five initial government-backed programme records across decommissioning, advanced reactors, supply chain and fusion—with financial stages kept explicit.
NRA status at 2026-10-29 · cross-checked
13 units with positive measured output · 2026-11-08 · nameplate capacity
OCCTO validated national total · 2026-11-08
JAIF fleet sheet · 2026-10-09
Approximate site placement over a Natural Earth coastline. Unit membership: JAIF 2026-10-09; green rings show positive measured generation in the complete OCCTO 2026-11-08 daily record, not live operation; NRA status is a 2026-10-29 cross-check.
Latest published month: September 2026 · 15 historically restarted reactors · 12 generated during the month · 3 recorded a full-month outage
| Reactor | September 2026 status | Time availability | Capacity factor | Generation |
|---|---|---|---|---|
| Sendai 1Kyushu EPC · 890 MWe | Generated | 100.0%720 of 720 h | 105.3% | 674,771 MWh |
| Sendai 2Kyushu EPC · 890 MWe | Generated | 100.0%720 of 720 h | 105.3% | 674,600 MWh |
| Takahama 4Kansai EPC · 870 MWe | Generated | 100.0%720 of 720 h | 104.3% | 653,280 MWh |
| Takahama 1Kansai EPC · 826 MWe | Generated | 100.0%720 of 720 h | 104.0% | 618,486 MWh |
| Takahama 2Kansai EPC · 826 MWe | Generated | 100.0%720 of 720 h | 103.8% | 617,240 MWh |
| Kashiwazaki-Kariwa 6TEPCO · 1,356 MWe | Generated | 100.0%720 of 720 h | 102.2% | 998,254 MWh |
| Ikata 3Shikoku EPC · 890 MWe | Generated | 100.0%720 of 720 h | 101.9% | 652,729 MWh |
| Shimane 2Chugoku EPC · 820 MWe | Generated | 100.0%720 of 720 h | 101.8% | 601,112 MWh |
| Genkai 4Kyushu EPC · 1,180 MWe | Generated | 100.0%720 of 720 h | 101.1% | 858,910 MWh |
| Onagawa 2Tohoku EPC · 825 MWe | Generated | 100.0%720 of 720 h | 101.0% | 599,759 MWh |
| Ohi 4Kansai EPC · 1,180 MWe | Generated | 100.0%720 of 720 h | 100.3% | 852,081 MWh |
| Mihama 3Kansai EPC · 826 MWe | Generated | 8.5%61 of 720 h | 2.2% | 12,996 MWh |
| Takahama 3Kansai EPC · 870 MWe | Full-month outage | 0.0%0 of 720 h | 0.0% | 0 MWh |
| Ohi 3Kansai EPC · 1,180 MWe | Full-month outage | 0.0%0 of 720 h | 0.0% | 0 MWh |
| Genkai 3Kyushu EPC · 1,180 MWe | Full-month outage | 0.0%0 of 720 h | 0.0% | 0 MWh |
How to read this: time availability is the share of monthly hours generating; capacity factor is measured generation relative to rated output. Values above 100% follow JAIF’s rated-output convention. A zero is an outage record, not evidence of poor performance while operating. Source: 日本の原子力発電所の運転実績 2026年9月, published 2026-10-09 · latest-release check 2026-11-10 · verified industry-primary.
Collected once daily, with the extraction quality and observation time made explicit for every source.
Output unavailable
Output unavailable
Output unavailable
Output unavailable
Numeric fields only · 10,000 kW converted to MW · accepted range 0–110% of nameplate.
Operator reports output adjustment in progress
Approx. from 100% of 1,180 MW nameplate
Approx. from 99% of 1,180 MW nameplate
Approx. from 103% of 826 MW nameplate
Approx. from 102% of 826 MW nameplate
Approx. from 0% of 870 MW nameplate
Approx. from 103% of 870 MW nameplate
*Approximate MW is calculated from the operator-reported percentage and nameplate capacity. Platform snapshot observed 04 Aug, 14:45 JST; open the operator source for a newer reading between daily collections.
83.4 × 10,000 kW converted to MW · 825 MW nameplate
0% operator reading converted to MW · 820 MW nameplate
Awaiting TEPCO numeric value · 1,356 MW nameplate
Output unavailable · 890 MW nameplate
No reliable current numeric output feed identified. Nothing is inferred from operating status.
Shimane 2 resumed generationChugoku Electric synchronized Shimane 2 to the grid at 14:00 on 19 August. Its measured ramp explains the national rise over the following days.
Chugoku Electric source ↗Onagawa 2 stopped for valve inspectionTohoku Electric confirmed that the 825 MW unit stopped generating at 01:00 on 17 October for a planned feedwater-heater relief-valve inspection. The lost output explains the 15.8 GWh national fall that day.
Tohoku Electric source ↗Onagawa 2 resumed generationTohoku Electric confirmed that the 825 MW unit resumed generation on 29 October and raised output. Its return accounts for part of the sharp rise at the end of October.
Tohoku Electric source ↗Genkai 3 returned from periodic inspectionKyushu Electric scheduled the 1,180 MW unit to resume generation on 29 October and ramp through adjustment operation; OCCTO's reactor-level measurements record that return. Together with Onagawa 2, the 2,005 MW of returning capacity explains the approximately 47.2 GWh/day national rise from 28 October to 3 November.
Kyushu Electric source ↗Official preliminary measured generation · all areas, nuclear filter · every displayed total recalculated from the underlying 30-minute unit rows · incomplete days rejected, never filled · static fallback collected 10 Nov 2026, 13:33 JST
33 existing JAIF OP table
15 historically restarted not “operating now”
Unavailable operating now no verified live feed connected
13 / 20 operation / suspended NRA snapshot 2026-10-29
3 under construction separate JAIF UC table
27 closed down separate JAIF CD table
Dated cross-check, not live. JAIF source date 2026-10-09; NRA source date 2026-10-29; collected 2026-07-30 JST. All 33 rows cross-checked. “Operating now” is intentionally unavailable.
Operator targets and regulatory facts are separated from possible future options. No synthetic progress scores.
1operator target
2advanced, no date
4under NRA review
10no active application
1regulatory block
Approximate site placement over a Natural Earth coastline. Each reactor is classified separately from the JAIF 2026-09-09 source snapshot; a target or review stage is not an operating status.
NRA installation-change permission granted 30 Jul 2025; Hokkaido governor accepted restart in Dec 2025.
Complete design-and-construction approvals, safety works and pre-use inspections.
NRA conformity approval obtained in 2018; safety measures, including the SSF, scheduled for completion in Dec 2026.
Complete construction and obtain the required local-government consent.
NRA conformity approval obtained in 2017; fuel loading and equipment checks were completed, then fuel removal began in Oct 2025.
TEPCO must confirm the unit sequence and secure the remaining restart readiness and local acceptance.
Application has been under NRA review since Jul 2013; no conformity approval.
Resolve review issues, complete safety works and obtain local acceptance.
Application has been under NRA review since Jul 2013; no conformity approval.
Resolve review issues, complete safety works and obtain local acceptance.
Application has been under NRA review since Jun 2014; safety-work completion date is undecided.
Complete the regulatory review and establish a safety-construction schedule.
The NRA received Chubu Electric's withdrawal of the Unit 3 installation-change application on 25 Sep 2026. There is no active new-regulation conformity application.
Operator decision and a new, credible conformity application before any regulatory restart pathway can resume.
The NRA received Chubu Electric's withdrawal of the Unit 4 installation-change, construction-plan and operational-safety-rule applications on 25 Sep 2026. There is no active new-regulation conformity application.
Operator decision and new, credible applications before any regulatory restart pathway can resume.
Application has been under NRA review since Aug 2014; no conformity approval.
Complete the regulatory review and address site and safety-work requirements.
Existing commercial reactor, but no new-regulation conformity application is recorded in the JAIF snapshot.
Operator decision to pursue restart and submit a regulatory application.
Existing commercial reactor, but no new-regulation conformity application is recorded for this unit in the JAIF snapshot.
TEPCO fleet strategy, regulatory application and local acceptance.
Existing commercial reactor, but no new-regulation conformity application is recorded for this unit in the JAIF snapshot.
TEPCO fleet strategy, regulatory application and local acceptance.
Existing commercial reactor, but no new-regulation conformity application is recorded for this unit in the JAIF snapshot.
TEPCO fleet strategy, regulatory application and local acceptance.
Existing commercial reactor, but no new-regulation conformity application is recorded for this unit in the JAIF snapshot.
TEPCO fleet strategy, regulatory application and local acceptance.
Existing commercial reactor, but no new-regulation conformity application is recorded for this unit in the JAIF snapshot.
TEPCO fleet strategy, regulatory application and local acceptance.
Existing commercial reactor, but no new-regulation conformity application is recorded in the JAIF snapshot.
Operator decision to pursue restart and submit a regulatory application.
Existing commercial reactor, but no new-regulation conformity application is recorded in the JAIF snapshot.
Operator decision to pursue restart and submit a regulatory application.
NRA concluded in Nov 2024 that the reactor did not meet the new regulatory standards.
The current regulatory outcome must be overcome before a restart pathway can exist.
Source snapshot: Japan Atomic Industrial Forum (JAIF), 2026-09-09; collected 30 Jul 2026 JST. “No restart date” means no operator restart schedule was identified in this source. Excludes periodic-outage returns and the three separate under-construction units.
Mitsubishi Heavy Industries raised its fiscal-2026 nuclear order forecast to ¥600 billion from ¥450 billion and its nuclear revenue forecast to ¥550 billion from ¥400 billion. The company attributes the order revision partly to increased fuel-cycle work and says it currently expects about ¥100 billion of production-capacity investment from fiscal 2027, including renewal of large processing equipment with new nuclear construction in view.
The disclosure is a primary-source signal of stronger near-term demand across Japan's nuclear and fuel-cycle supply chain and a concrete commitment to expand heavy-manufacturing capacity for future projects. The ¥100 billion figure is a forward investment plan, not completed spending or evidence that a new reactor project has been approved.
2026年度第2四半期決算説明資料
Published 6 Nov 2026 · collected 9 Nov 2026, 19:50 JST
Verified · primary sourceKyushu Electric applied to the NRA to amend the approved long-term facility-management plans for Sendai 1 and 2 after deciding to add a new type of electrical penetration. The operator says its additional evaluation found no soundness problem at the 60-year operating point and no additional maintenance activity required for the new type.
The filing updates the regulatory ageing-management basis for two operating 890 MW reactors. It is an application, not an approval: the change remains subject to NRA review and does not alter either unit's current operating classification or establish completion of the regulatory process.
川内原子力発電所１、２号機 長期施設管理計画の変更認可申請について
Published 6 Nov 2026 · collected 6 Nov 2026, 13:45 JST
Verified · primary sourceThe NRA's 29 October dated page classifies 13 of Japan's 33 existing commercial reactors as operating and 20 as suspended. Compared with the retained 20 October snapshot, Onagawa 2 and Genkai 3 moved from suspended to operating; the other unit classifications are unchanged.
The dated regulatory snapshot adds 2,005 MW of unit membership to the NRA operating category and updates the Fleet Pulse and fleet register. It is not presented as a live output feed: current operator observations and OCCTO measured generation remain separately labelled.
発電所の現在の運転状況
Published 29 Oct 2026 · collected 30 Oct 2026, 19:42 JST
Verified · primary sourceTohoku Electric's 04:40 operator page says Onagawa 2 resumed electricity generation on 29 October after the reactor restart reported on 26 October. The unit was in the process of raising output when the page was inspected.
This is the first primary-source confirmation that the 825 MW unit progressed from reactor startup to electricity generation after its valve inspection outage. It does not establish full output or a completed return to steady commercial operation, which remain separate milestones.
女川原子力発電所発電機出力グラフ
Published 29 Oct 2026 · collected 29 Oct 2026, 07:34 JST
Verified · primary sourceKansai Electric says Ohi 3's 22nd periodic inspection, which began on 5 October without a published completion schedule, is now planned to reach grid parallel in late January. The operator will replace the exciter as part of corrective work following the generator and reactor trip on 8 August.
The schedule provides a new primary-source indication of when 1,180 MW could begin returning to the grid and supports maintenance, fuel and wholesale-market planning. Late-January parallel is a plan, not a completed restart or confirmation of full output.
大飯発電所３号機の定期検査工程の変更
Published 29 Oct 2026 · collected 29 Oct 2026, 19:35 JST
Verified · primary sourceKyushu Electric, Kyuden Holdings and Karatsu City signed an amended safety agreement for the Genkai nuclear station following the holding company's creation on 1 October. The agreement adds Kyuden Holdings as a party and states that it must support Kyushu Electric in fulfilling the agreement, while Kyushu Electric remains the nuclear operator.
The amendment clarifies safety-governance responsibilities after the corporate restructuring and preserves a direct local-government accountability framework. It is a governance change, not an operating-status or consent milestone for any reactor.
キューデンホールディングス株式会社設立に伴い玄海原子力発電所に関する「唐津市域の安全確保に関する協定書」を締結しました
Published 29 Oct 2026 · collected 30 Oct 2026, 07:35 JST
Verified · primary sourceTohoku Electric's 03:00 operator page says inspection of the high-pressure feedwater-heater B relief valve was completed and the Onagawa 2 reactor was started on 26 October. The operator says generation will resume once preparations are complete.
This converts the reactor-start milestone from a prospective HJKS signal into a verified operator-reported event for the 825 MW unit. It does not establish grid connection, electricity generation or full commercial operation; those later milestones remain unverified until separately confirmed.
女川原子力発電所発電機出力グラフ
Published 27 Oct 2026 · collected 27 Oct 2026, 07:31 JST
Verified · primary sourceTohoku Electric says reinforcing steel made from clearance metal generated during decommissioning work at Hamaoka 1 and 2 was delivered to Higashidori on 26 October. The material is planned for the foundations of an additional on-site warehouse and will be Tohoku Electric's first use of clearance metal as construction material.
The project is a concrete domestic reuse pathway for very-low-activity metal that has passed the regulatory clearance process, linking decommissioning waste reduction with construction procurement. Delivery is complete, but use in the warehouse foundation remains planned and is not presented as completed construction.
東通原子力発電所におけるクリアランス金属の建設資材への再利用について
Published 26 Oct 2026 · collected 26 Oct 2026, 17:34 JST
Verified · primary sourceTEPCO says the sixth ALPS-treated-water discharge of fiscal 2026, and 24th overall, finished at 12:09 JST on 23 October after the transfer from measurement tanks ended on 22 October and residual water in the transfer line was flushed. The completed release ran from 5 to 23 October, discharged 7,852 cubic metres and contained about 1.2 trillion becquerels of tritium.
This converts the previously published start and planned parameters into a verified completed decommissioning operation. TEPCO says daily diluted-water checks remained below 1,500 becquerels per litre and its rapid seawater results remained below investigation and suspension levels; the record does not establish the status of the separately scheduled seventh discharge.
福島第一原子力発電所 2026年度第6回（通算24回）ALPS処理水海洋放出の完了
Published 23 Oct 2026 · collected 24 Oct 2026, 13:33 JST
Verified · primary sourceKyushu Electric submitted the eighth statutory safety-improvement evaluations for Sendai 1 and 2 to the NRA. The operator says the reviews confirmed that existing safety activities and previously implemented measures remain effective, and identified further work covering instrumentation-and-control upgrades, equipment changes to reduce severe-accident workload, heat-stress measures in radiological areas, spent-fuel dry storage and enhanced education and training.
The filing provides current primary-source evidence of the operator's next safety-investment priorities for two generating 890 MW units. It is a submitted evaluation and programme of further measures, not evidence that every identified upgrade or the planned dry-storage facility is complete.
川内原子力発電所１号機第８回及び川内原子力発電所２号機第８回安全性向上評価の届出書を提出しました－安全性向上のための評価と今後の取組み－
Published 23 Oct 2026 · collected 24 Oct 2026, 13:33 JST
Verified · primary sourceKyushu Electric says Genkai 3 has nearly completed the inspections required while shut down for its 19th periodic inspection. The operator plans to start the reactor and reach criticality on 27 October, resume generation on 29 October, then raise output progressively during adjustment operation before a planned return to normal operation on 25 November.
The operator's schedule provides primary-source milestones for the expected return of a 1,180 MW unit and corroborates the prospective HJKS output-reduction window already tracked. Every date remains a plan: reactor startup, criticality, grid generation and normal-operation return must each be verified after they occur and are not presented as completed or live.
玄海原子力発電所３号機の発電再開予定をお知らせします
Published 23 Oct 2026 · collected 24 Oct 2026, 07:50 JST
Verified · primary sourceA new official JEPX HJKS disclosure schedules a Genkai 3 output-reduction window from 15:00 JST on 29 October, with restoration indicated for 1 November. The record gives a 556 MW registered reduction and states maximum and minimum reductions of 1,121 MW and 295 MW.
Genkai 3 is currently in periodic inspection, so the disclosure is a forward operational signal relevant to the unit's return pathway. HJKS labels it as a future output-reduction event; it does not establish reactor startup, grid connection, commercial-operation resumption or current generation.
玄海原子力発電所３号機 出力低下
Published 22 Oct 2026 · collected 22 Oct 2026, 16:08 JST
Verified · primary sourceA new official JEPX HJKS disclosure schedules an Onagawa 2 startup-curve output-reduction window from 18:00 JST on 28 October, with restoration indicated for 31 October. The record gives a 127 MW registered reduction and identifies the cause as output reduction associated with the startup curve.
The disclosure provides the first official forward signal in this feed for Onagawa 2's expected return after its 17 October planned shutdown. It remains a schedule: Tohoku Electric's latest inspected operator page still records the unit stopped, and no restart, grid connection or current generation is claimed until separately verified.
女川原子力発電所２号機 出力低下（起動カーブに伴う出力低下）
Published 22 Oct 2026 · collected 22 Oct 2026, 16:08 JST
Verified · primary sourceTEPCO says its analyses and an external laboratory's results met the release criteria for the fiscal-2026 seventh ALPS-treated-water discharge. It plans to begin on 26 October and finish on 13 November, discharging about 7,800 cubic metres with an estimated total tritium amount of about 1.4 trillion becquerels and an estimated post-dilution concentration of about 240 becquerels per litre.
The primary-source schedule defines the next monitored Fukushima Daiichi discharge window and its planned parameters. The analysis result is verified, but the 26 October start, 13 November completion and planned volumes remain prospective and must not be presented as completed operations.
福島第一原子力発電所 2026年度第7回（通算25回）ALPS処理水海洋放出に向けた分析結果と開始予定日
Published 22 Oct 2026 · collected 24 Oct 2026, 13:33 JST
Verified · primary sourceKansai Electric says the C pressurizer safety-valve outlet temperature at Takahama 1 began rising again at 15:00 JST on 20 October and reached about 66°C by 14:00 on 21 October, after remaining within its usual range of about 50°C or below since 5 October. The unit remained in constant rated thermal-power operation, other plant parameters were normal and the operator reported no radiological impact.
The renewed increase warrants continued monitoring because it affects a safety-valve train at an operating 826 MW reactor. The operator has not reported a shutdown, power reduction or abnormality in other plant parameters, so this notice is not used to infer any output change.
高浜発電所１号機 Ｃ加圧器安全弁の出口温度上昇に伴う監視強化の状況
Published 21 Oct 2026 · collected 22 Oct 2026, 07:33 JST
Verified · primary sourceThe NRA's 20 October dated page classifies 11 of Japan's 33 existing commercial reactors as operating and 22 as suspended. Compared with the previously retained NRA snapshot, Onagawa 2 and Ohi 3 are now suspended, while Mihama 3 and Shimane 2 are operating. Kashiwazaki-Kariwa 6 remains classified as operating.
The total operating denominator is unchanged, but its unit membership has materially changed. This dated regulatory snapshot updates the Fleet Pulse and fleet register without being presented as a live status feed; current operator observations and OCCTO measured generation remain separately labelled.
発電所の現在の運転状況
Published 20 Oct 2026 · collected 21 Oct 2026, 22:14 JST
Verified · primary sourceTohoku Electric says Onagawa 2 stopped generating at 01:00 JST on 17 October and reached cold shutdown at 13:57 JST. The operator will inspect, dismantle and replace parts in the high-pressure feedwater-heater B relief valve after monitoring a small water leak into a controlled drain tank.
This converts the previously announced roughly ten-day stop from a schedule into a verified operational event affecting an 825 MW reactor. OCCTO's complete 17 October national record is consistent with a partial generating day for Onagawa 2, but it is not used to claim a live reactor state. Restart remains prospective until separately confirmed by the operator.
女川原子力発電所2号機における原子炉の計画停止について
Published 17 Oct 2026 · collected 19 Oct 2026, 09:05 JST
Verified · primary sourceTohoku Electric says it plans to stop Onagawa 2 around 17 October to dismantle, inspect and replace parts in a relief valve on high-pressure feedwater heater B. The operator has monitored a small water leak into a controlled drain tank since 1 September and says the amount increased slightly. It expects the interval from shutdown to restart to be about ten days.
The planned stop temporarily removes an 825 MW reactor from generation and should be visible in national output after it occurs. The operator says the water is collected and treated, there is no environmental radiological impact and the event is not reportable under national law. The schedule is verified, but the stop and restart remain future actions and are not presented as completed or live.
女川原子力発電所2号機における高圧第1給水加熱器(B)水室逃し弁の点検実施に伴う原子炉の計画停止について
Published 15 Oct 2026 · collected 15 Oct 2026, 16:11 JST
Verified · primary sourceOCCTO's complete national record for 11 October contains positive 30-minute measured generation for Mihama 3. The validated national total was 254.011 GWh across all 33 nuclear-unit records, with 30 complete measured rows, three fully blank non-reporting rows and 12 units reporting positive generation.
This is official dated evidence that the 826 MW unit generated during 11 October after Kansai Electric's planned reactor-start milestone. It is not a live operating-status claim and does not verify completion of adjustment operation or the planned November commercial-operation milestone. The incomplete 10 October OCCTO record remains rejected, so no day-on-day change is calculated across that gap.
発電情報公開システム
Published 12 Oct 2026 · collected 12 Oct 2026, 19:30 JST
Verified · primary sourceKansai Electric says repairs and preparations are complete after identifying an external-corrosion hole in piping near the 6A high-pressure feedwater-heater level-control valve. The operator plans to start the Mihama 3 reactor and begin adjustment operation on 10 October, followed by full commercial operation after the integrated load-performance test on 4 November.
The schedule provides a primary-source pathway for the return of an 826 MW reactor that stopped manually on 18 September. Both dates are planned milestones: this record does not verify that reactor start, grid synchronization or commercial-operation resumption has occurred.
美浜発電所３号機の原子炉起動および調整運転の開始予定について（６Ａ高圧給水加熱器常用水位制御弁出口配管の空気抜き弁周辺からの水の滴下）
Published 9 Oct 2026 · collected 9 Oct 2026, 19:42 JST
Verified · primary sourceJAIF's September performance report records 7,814,218 MWh of generation across the 33-unit existing commercial fleet, with an aggregate capacity factor of 32.8%. Twelve of the 15 historically restarted reactors generated during the month. Mihama 3 generated for 61 hours before stopping again, while Takahama 3, Ohi 3 and Genkai 3 recorded full-month outages. JAIF's companion 9 October fleet sheet retains 33 existing units and 15 historically restarted units.
The publication provides the freshest comparable monthly unit-level capacity-factor and time-availability evidence and updates the website's reactor-performance table. It is a monthly JAIF compilation of utility data, not a live operating-status feed; values above 100% follow JAIF's rated-output convention.
「日本の原子力発電所の運転実績（2026年9月）」等の掲載について
Published 9 Oct 2026 · collected 9 Oct 2026, 13:48 JST
Verified · primary sourceThe Japan Atomic Human Resource Consortium (J-AHRC) launched on 7 October as a reorganization of the Nuclear Human Resource Development Network. JAIF says the 84 participating institutions are expected to continue, while 13 founding organizations will operate a standing secretariat and implementation structure. The consortium plans to quantify workforce gaps by occupation and specialty and prepare a roadmap during fiscal 2026.
This creates a more execution-oriented industry, government and academic mechanism for a constraint that affects reactor operation, maintenance, decommissioning and potential replacement construction. The launch is verified through JAIF, a founding organization; future workforce numbers and the roadmap remain planned outputs, not completed findings.
原子力人材確保へ新コンソーシアム発足 課題解決に向けた実行体制へ機能強化
Published 8 Oct 2026 · collected 9 Oct 2026, 07:45 JST
Verified · primary sourceJEPX HJKS updated Kyushu Electric's Genkai 4 planned-outage disclosure. The outage remains scheduled to begin at 09:00 JST on 12 November 2026, while the expected restoration date moved one day earlier, from 19 January to 18 January 2027.
The revision modestly shortens the disclosed maintenance window for a 1,180 MW operating reactor and refines winter supply planning. It is a future operator schedule disclosure, not evidence that Genkai 4 is currently offline or that the restoration date is guaranteed.
玄海原子力発電所 ４号機・計画停止・停止／定期検査等
Published 5 Oct 2026 · collected 5 Oct 2026, 19:38 JST
Verified · primary sourceTEPCO says it began the fiscal-2026 sixth—and 24th overall—ALPS-treated-water discharge at 11:21 JST on 5 October. The operator reported that external and internal analyses met the applicable release criteria. It plans to discharge about 7,800 cubic metres through 23 October, with an estimated total tritium amount of about 1.2 trillion becquerels and an expected post-dilution concentration of about 200 becquerels per litre.
This converts a previously announced schedule into a verified operational decommissioning event and starts the latest monitored discharge window. The source verifies the start and planned parameters; it does not verify completion, and monitoring results during the discharge remain relevant.
福島第一原子力発電所 2026年度第6回（通算24回）ALPS処理水海洋放出の開始
Published 5 Oct 2026 · collected 7 Oct 2026, 14:10 JST
Verified · primary sourceFollowing the 1 October establishment of Kyuden Holdings, Kagoshima Prefecture, Satsumasendai City, Kyushu Electric Power and the new holding company signed an amended safety agreement and exchanged an updated memorandum concerning the Sendai nuclear power station. Kyushu Electric says it remains the entity responsible for the nuclear business.
The four-party arrangement clarifies local-government oversight and corporate accountability after the group reorganization. It does not change Sendai 1 or 2's verified generating status, reactor licensing or output.
キューデンホールディングス株式会社設立に伴い川内原子力発電所に関する安全協定を締結しました
Published 5 Oct 2026 · collected 6 Oct 2026, 19:45 JST
Verified · primary sourceTEPCO's 1 October roadmap material says work using the Fukushima Daiichi Unit 2 robotic arm was scheduled to start on 2 October with construction of an access route into the primary containment vessel. TEPCO says the overall sequence—access-route construction, three-dimensional mapping, debris sampling and other data collection—is expected to involve about six months of remote operations.
The plan moves a larger robotic system toward detailed internal investigation and trial fuel-debris retrieval, a technically important step in Fukushima Daiichi decommissioning. The primary source states a scheduled start: it does not verify that work began, that the arm reached the target area or that debris was retrieved.
２号機 PCV内部調査・試験的取り出し作業の状況
Published 1 Oct 2026 · collected 2 Oct 2026, 19:45 JST
Verified · primary sourceHitachiomiya Mayor Sadayuki Suzuki announced that the city will accept the economy minister's request for a literature survey concerning geological disposal of high-level radioactive waste. The mayor said the decision followed discussions with the national government and framed the survey as an initial evidence-gathering step.
The decision adds a new municipality to Japan's first-stage final-disposal siting process and broadens the geographic pipeline for resolving a national fuel-cycle constraint. Acceptance does not mean a repository has been selected, that field investigation has begun or that later-stage local consent has been granted.
文献調査受け入れに係る市長発言（令和8年9月30日記者会見）
Published 30 Sept 2026 · collected 2 Oct 2026, 13:40 JST
Verified · primary sourceTohoku Electric moved the planned start of construction for Onagawa 2's first spent-fuel dry-storage building from September to December 2026 and its planned start of operation from March to December 2028. The operator cited additional time required for regulatory review and authorization, and submitted a related construction-plan change notice to the NRA.
The nine-month shift delays additional spent-fuel management capacity at an operating reactor and may affect future fuel-pool and outage logistics. It is an operator schedule revision, not regulatory approval, construction completion or an operating-status change.
女川原子力発電所2号機における使用済燃料乾式貯蔵施設第1棟目の着工および運用開始時期見直しについて
Published 29 Sept 2026 · collected 1 Oct 2026, 19:40 JST
Verified · primary sourceTohoku Electric revised the planned completion of Onagawa 2's third permanent on-site DC power system from March to August 2028 after reassessing the large-scale work required inside the reactor building. The operator submitted revised operating-plan and construction-plan notices to the NRA; the applicable transitional deadline is December 2029.
The change updates the delivery schedule for a required resilience system but remains inside the stated regulatory transition period. It does not establish a shutdown, loss of compliance, regulatory approval or current output change.
女川原子力発電所2号機運転計画を踏まえた「所内常設直流電源設備（3系統目）」の工事完了時期見直しについて
Published 29 Sept 2026 · collected 1 Oct 2026, 19:40 JST
Verified · primary sourceDuring power-ascension checks at Mihama 3, Kansai Electric found water dripping at about three drops per second from insulation around an air-vent valve on the outlet piping of the No. 6A high-pressure feedwater heater's normal water-level control valve. The operator decided at 17:45 JST on 17 September to stop the reactor for inspection and began reducing load at 20:30. JEPX HJKS subsequently recorded a planned outage entry beginning at 01:30 on 18 September, with the cause under investigation and no restoration outlook stated.
The 826 MW unit had positive measured output in the latest complete OCCTO national record, so the shutdown can materially reduce subsequent national nuclear generation. The 16 September Fleet Pulse remains a dated measured snapshot and is not rewritten as live output; the next complete OCCTO day will determine the measured national effect.
美浜発電所３号機の原子炉手動停止
Published 17 Sept 2026 · collected 18 Sept 2026, 11:24 JST
Verified · primary sourceThe NRA received Chubu Electric's withdrawal of the Hamaoka 3 and 4 reactor-installation-change applications and Unit 4's construction-plan and operational-safety-rule applications on 25 September. This completes the filing step announced in the operator's 14 September board decision.
Neither unit now has an active new-regulation conformity application, so both move from active NRA review to the no-active-application segment of the restart pipeline. Any future restart case depends on new, credible applications and supporting evidence. The withdrawals do not remove the units from the 33-unit existing fleet and are not decommissioning decisions.
中部電力(株)から浜岡原子力発電所3号炉及び4号炉の新規制基準適合性に係る発電用原子炉設置変更許可申請等の取下書を受理
Published 25 Sept 2026 · collected 28 Sept 2026, 07:45 JST
Verified · primary sourceThe NRA received TEPCO's report that a water leak in the cylinder head of Unit 6 emergency diesel generator B made the generator unavailable. That also made the Unit 6-to-7 inter-unit emergency power-transfer function unavailable, leading to operating-limit deviation declarations for Units 6 and 7.
The event temporarily reduces credited backup-power availability across the two-unit safety arrangement and requires prompt corrective action under the operating rules. The NRA notice does not establish a reactor shutdown or generation loss, and this item does not treat the deviation as either.
東京電力ホールディングス(株)から柏崎刈羽原子力発電所6号機及び7号機における運転上の制限からの逸脱に係る報告を受理
Published 11 Sept 2026 · collected 13 Sept 2026, 07:37 JST
Verified · primary sourceAt the NRA's 10 September review meeting, Chugoku Electric submitted responses on Shimane 3's accident-sequence selection, probabilistic risk assessment, portable severe-accident equipment locations and access routes, together with an updated review-explanation schedule.
The submissions move a 1,373 MW reactor under construction through a substantial block of the new-regulatory-standard review. The meeting and documents do not establish NRA approval, construction completion, fuel loading or a confirmed operating date.
第1435回原子力発電所の新規制基準適合性に係る審査会合
Published 10 Sept 2026 · collected 12 Sept 2026, 07:33 JST
Verified · primary sourceIn material submitted to the NRA, Japan Nuclear Fuel proposed moving verification runs using process solutions and high-level liquid waste to before completion of the Rokkasho reprocessing plant. The runs are intended to confirm long-idled equipment and vitrification-system performance.
The proposal changes the planned commissioning sequence for a central constraint in Japan's nuclear fuel cycle and could improve evidence available before completion. It remains an operator proposal under regulatory review: the NRA record does not establish approval, completion, commercial operation or a revised completion date.
日本原燃株式会社 再処理施設 廃棄物管理施設 設工認申請の対応状況について
Published 7 Sept 2026 · collected 11 Sept 2026, 07:42 JST
Verified · primary sourceThe NRA opened public consultation on a draft amendment to the review standard for commercial-reactor operational safety regulations. The comment period runs from 3 September through 2 October 2026.
The proposal could change the regulatory framework utilities use for maintenance while reactors are operating, affecting outage planning and plant work management. It remains a draft under consultation and is not an enacted rule or a reactor-level operating-status change.
実用発電用原子炉及びその附属施設における発電用原子炉施設保安規定の審査基準の一部を改正する規程（案）に対する意見公募について
Published 3 Sept 2026 · collected 3 Sept 2026, 19:30 JST
Verified · primary sourceTohoku Electric confirmed that it submitted an installation-change permit application to the NRA for replacing Onagawa 2's containment hydrogen concentration monitors, one day after initiating prior consultation with Miyagi Prefecture, Onagawa Town and Ishinomaki City.
The filing converts a planned regulatory step into a verified application and opens the NRA review path for the equipment change. It is not an approval, installation completion or operating-status change; Tohoku says it will respond to the forthcoming review.
女川原子力発電所２号機における原子炉格納容器内水素濃度計の変更に係る原子炉設置変更許可申請について
Published 2 Sept 2026 · collected 2 Sept 2026, 19:30 JST
Verified · primary sourceKyushu Electric confirmed receipt of 24 new fuel assemblies for Sendai 1 and 28 for Sendai 2 after a combined land-and-sea shipment from Nuclear Fuel Industries conducted from 30 August through 2 September.
The completed delivery is a verified fuel-supply and outage-planning milestone for two operating reactors and a concrete demand signal for Japan's domestic PWR fuel chain. It does not establish that the fuel has been loaded or change either unit's operating status.
川内原子力発電所の新燃料輸送を行いました－１号機用として24体、２号機用として28体の新燃料を受入れ－
Published 2 Sept 2026 · collected 2 Sept 2026, 19:30 JST
Verified · primary sourceTohoku Electric initiated local prior consultation for replacing Onagawa 2's containment hydrogen concentration monitors with a detector design it says has better operability and maintainability. The change follows detector faults in May and June 2025; monitoring currently continues with quality-improved detectors.
The proposal addresses a known reliability and maintenance burden in post-accident hydrogen monitoring. Tohoku says it plans an NRA installation-change application and implementation during the 13th periodic inspection, but neither regulatory approval nor installation is complete and no operating-status change is inferred.
女川原子力発電所２号機における原子炉格納容器内水素濃度計の変更に係る事前協議申し入れについて
Published 2 Sept 2026 · collected 2 Sept 2026, 07:43 JST
Verified · primary sourceKyushu Electric confirmed that 72 new fuel assemblies for Genkai 4 were transported from Mitsubishi Nuclear Fuel and received after a combined land-and-sea shipment conducted from 27 August through 1 September.
The completed delivery is a verified fuel-supply and outage-planning milestone for an operating reactor and a concrete order-flow signal for Japan's domestic PWR fuel chain. It does not indicate that the assemblies have been loaded or change Genkai 4's current operating status.
玄海原子力発電所の新燃料輸送を行いました－４号機で使用する72体の新燃料を受入れ－
Published 1 Sept 2026 · collected 1 Sept 2026, 19:30 JST
Verified · primary sourceFukui Prefecture announced prior consent for Kansai Electric's spent-fuel dry-storage plans at Mihama and for the first phase at Takahama. Kansai Electric separately states that the consent covers those two plans; the company still needs the applicable detailed regulatory approvals before construction can proceed.
The decision clears a material local-consent gate for additional on-site spent-fuel management capacity at two operating stations. It supports fuel-pool management and future transport logistics, but it does not mean either facility is built, licensed for use or operating, and it does not cover the still-pending Ohi plan.
関西電力の乾式貯蔵施設設置計画の事前了解について
Published 28 Aug 2026 · collected 1 Sept 2026, 07:44 JST
Verified · primary sourceThe NRA received Shikoku Electric's report that one of four overtemperature delta-T protection channels produced an unreliable signal at Ikata 3. After confirming the other three channels remained operable, the affected channel was bypassed and the unit returned to compliance with its operating limits.
The notice records a verified temporary reduction in protection-channel redundancy and its recovery. It does not establish a reactor shutdown, generation loss or continuing non-compliance, so no operating-status or output change is inferred from it.
四国電力(株)から伊方発電所3号機における運転上の制限からの逸脱及び復帰に係る報告を受理
Published 27 Aug 2026 · collected 1 Sept 2026, 13:44 JST
Verified · primary sourceThe Cabinet Secretariat says the government compiled the Power GX package following the 17th GX Implementation Council on 26 August. The package calls for maximum use of nuclear power alongside renewables as part of strengthening Japan's energy-supply structure; it is a policy direction, not approval or a restart decision for any reactor.
The package raises the policy priority attached to nuclear utilization and may affect future restart support, investment frameworks and supply-chain demand. Reactor-level timing still depends on NRA review, operator readiness and local processes, so no fleet-status change is inferred from the package.
エネルギー需給構造強靭化総合パッケージ（パワーGX）
Published 26 Aug 2026 · collected 31 Aug 2026, 09:41 JST
Verified · primary sourceDenki Shimbun reports that Japan's BWR operators plan to apply to the NRA in early 2029 for installation changes needed to introduce 10×10 fuel assemblies, which use more fuel rods than conventional 9×9 fuel. The NRA confirms that one 10×10 product received type certification in late June; the 2029 timetable remains attributed to Denki Shimbun.
This provides the first identified operator timetable for moving the new fuel from generic design approval toward plant-specific deployment. Adoption could improve safety performance and fuel utilization, while creating a multi-year regulatory and procurement pathway for BWR utilities and fuel suppliers. No plant-specific application or installation date has yet been announced.
ＢＷＲ新燃料、２９年許可申請へ／安全性向上見込む（1面）
Published 14 Aug 2026 · collected 14 Aug 2026, 07:52 JST
Reported · Denki ShimbunThe NRA received a legally reportable event notice after Ohi 3 automatically shut down from rated thermal-power operation on 9 August. NRA inspectors confirmed no environmental impact. KEPCO lists the unit as stopped and published an investigation update on 19 August; the cause investigation remains ongoing.
This is a verified operating-status change for one of the historically restarted reactors and explains why Ohi 3 cannot be counted as currently generating. It also explains the missing-unit validation failures in OCCTO's national daily records from 9 August onward; no restart timing should be inferred until KEPCO confirms it.
関西電力(株)から大飯発電所3号機における原子炉の自動停止について報告を受理
Published 10 Aug 2026 · collected 21 Aug 2026, 19:46 JST
Verified · primary sourceJAIF published its monthly July operating-results tables, including unit, reactor-type and utility capacity factors plus updated operating, construction, planned and closed-down reactor tables.
The publication provides a dated monthly fleet and performance cross-check. It is not a live operating-status source and does not by itself change the 33-reactor existing-fleet denominator.
「日本の原子力発電所の運転実績（2026年7月）」等の掲載について
Published 7 Aug 2026 · collected 10 Aug 2026, 13:41 JST
Verified · primary sourceThe NRA convened a non-public review concerning specified severe-accident response facilities at Kashiwazaki-Kariwa Units 6 and 7. No decision or substantive meeting material was published with the notice.
The meeting is evidence of regulatory activity, not evidence of approval or restart progress. Its closed status means no milestone should be inferred until the NRA publishes an outcome.
第1423回原子力発電所の新規制基準適合性に係る審査会合
Published 30 Jul 2026 · collected 30 Jul 2026, 13:38 JST
Verified · primary sourceKyushu Electric reported that no abnormalities had been identified at the Genkai and Sendai nuclear stations following recurring earthquakes in Kumamoto from 28 July.
This closes the immediate plant-condition question raised by the earthquakes. It is an operator condition report, not a new numeric output reading.
熊本県天草・芦北地方での地震における川内及び玄海原子力発電所の状況について
Published 29 Jul 2026 · collected 30 Jul 2026, 13:38 JST
Verified · primary sourceTohoku Electric filed a change notice moving the planned construction start for Onagawa 2's first spent-fuel dry-storage building from July to September 2026 while design-and-construction approval review continues. The planned March 2028 start of operation is unchanged.
The two-month construction shift is a concrete fuel-cycle schedule change and signals continued regulatory-review timing risk, without changing the stated 2028 commissioning target or the reactor's operating status.
女川原子力発電所2号機の原子炉設置許可に係る工事計画変更届出について（使用済燃料乾式貯蔵施設第1棟目の着工時期の変更）
Published 27 Jul 2026 · collected 31 Jul 2026, 21:21 JST
Verified · primary sourceJapan Nuclear Fuel Limited said Aomori Prefecture and Rokkasho Village gave prior consent to its plan to increase the uranium-enrichment plant's maximum depleted-uranium storage capacity. The supporting plan identifies a July 2026 amendment application and a September 2028 target for use of the changed facilities.
The consent clears a local procedural gate for fuel-cycle infrastructure needed as enrichment operations expand. It is not an NRA approval and does not establish that the additional capacity is already available.
六ヶ所ウラン濃縮工場に係る新増設等計画書に関する事前了解について
Published 24 Jul 2026 · collected 13 Aug 2026, 11:10 JST
Verified · primary sourceShikoku Electric published a notice concerning an instrument used for secondary-system water chemistry at steam generator 3A.
The notice is operationally relevant, but it is not treated as evidence of a reactor shutdown or a live-output change without a separate operator confirmation.
伊方発電所3号機 蒸気発生器3Aにおける2次系水質計器の不具合について
Published 21 Jul 2026 · collected 30 Jul 2026, 11:46 JST
Verified · primary sourceKansai Electric lists Takahama 2 as having resumed full commercial operation on 16 July after its periodic inspection.
This is a verified operating-status change and is reflected in the dated operating-capacity snapshot. It does not change the 33-reactor existing-fleet denominator.
高浜発電所２号機の本格運転再開
Published 16 Jul 2026 · collected 30 Jul 2026, 11:46 JST
Verified · primary sourceShikoku Electric submitted the fifth safety-improvement assessment for Ikata 3, as required after operation under the post-Fukushima regulatory framework.
The filing adds a new regulatory record for the operating unit; it is not presented as a new operating permit or restart approval.
伊方発電所3号機 安全性向上評価届出書(第5回)の提出について
Published 15 Jul 2026 · collected 30 Jul 2026, 11:46 JST
Verified · primary sourceJapan Steel Works' updated medium-term plan calls for nuclear-product production capacity in the year ending March 2029 to reach twice the year-ending March 2026 level, amid anticipated large-reactor and SMR demand overseas.
This is a concrete Japanese nuclear-supply-chain expansion signal with potential implications for forgings and other long-lead components. It is a capacity plan, not evidence of secured reactor orders or completed expansion.
中期経営計画「JGP2028」アップデートの策定に関するお知らせ
Published 13 Jul 2026 · collected 13 Aug 2026, 11:10 JST
Verified · primary sourceKyushu Electric completed inspections of facilities required to retain their safety functions during decommissioning at Genkai 1 and 2.
This is decommissioning progress for permanently closed units. The items remain outside the 33-unit existing commercial-reactor denominator.
玄海原子力発電所１、２号機の定期事業者検査（廃止措置段階）が終了しました
Published 9 Jul 2026 · collected 30 Jul 2026, 11:46 JST
Verified · primary source