《福島事件後龍門電廠(核四廠)壓力測試審查》

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2013 年 9 月 9 日

福島事件後龍門電廠(核四廠)壓力測試審查 Review of the post-Fukushima nuclear stress-tests of the Lungmen nuclear power plant (NPP4) 臺灣原子能委員會在 2012 年宣布將採用在歐盟實施的福島核災後壓力測試方式作為基礎,進行臺 灣核電廠的壓力測試。 如同歐盟,綠色和平邀請物理學家 Oda Becker 針對臺灣目前核能計畫的重點 -- 核四廠的壓力測 試報告進行評估。此次評估中得到一個清楚的結論,若要改善反應爐目前的狀態以把核災風險降至 最低是有困難的。此外,再加上因福島核災後對於核四廠的核安升級建議不甚明確,便已足夠構成 充分的理由說明核四廠不應該繼續建蓋直至最終取得運轉執照。 福島核災所造成的恐怖結果是因為數十年來錯誤的安全觀念所造成的。強大核能工業壓力的影響下 ,以至於管制機構的安全規範極度鬆散-這不只存在於日本。福島事件對歐盟造成的首要影響,便 是歐盟決心改變核能安全的問題,在管理機制中加入原本被因為機率過低而被排除在安全案例之外 的各種可能發生事件。 導致歐盟深切的希望能對於核能及其相關安全性之問題有所改變,並且認為這些改變是絕對有可能 發生的。以上的考量在以前都因為被認為核災發生的機率很小而被忽略。 針對此次事件的回應,歐盟進行了一系列的壓力測試,希望這些測試可以降低歐洲國家的核災風 險。此次壓力測試讓歐洲建有核電廠的國家開始著手訂立國家型行動計劃,就在過去兩年中所發現 的缺失加以改善。綠色和平針對這些計劃進行評估,而評估結果指出,儘管在壓力測試後歐盟國家 已經大量投入與核能安全相關的安全升級1,但許多關鍵的核安相關的問題仍然未獲解決。另外,即 使是目前已經在處理的問題,也需要再幾年的時間才能予以修正,在此期間,歐洲人民仍暴露在核 能安全的風險之中。 綠色和平推論,歐盟管制機構宣稱其壓力測試獲得最高分,是因為歐盟國家打算儘管已知自己的反 應爐有缺陷,仍然打算持續運轉。公民團體的代表及專家憂心,歐盟的壓力測試主要目的僅是用來 提升歐洲核電管理部門對於核能安全的信心,而不是真正探究核能本身已經或將會產生的問題。不 幸的是,這樣的觀點似乎是真的。 臺灣所進行的壓力測試比歐盟更加不符合壓力測試應發揮之功能,該壓力測試的時機剛好是在核四 公投之前,致使其將抹上為核四安全背書的公關色彩。 Oda Becker 的分析結果顯示,臺灣核四廠計畫中的壓力測試令人憂心。再加上考量到核四先前所經 歷的各種波折,她的結論是最好取消核四計畫。 綠色和平遵照 Oda Becker 的建議向臺灣政府建議,不論公投是否舉辦、結果為何都應該中止核四 計畫,並且以其他較安全的能源提供滿足電力需求,例如:執行節能措施或再生能源的使用。 1

歐盟執委會估計歐盟在壓力測試後進行的核能升級總花費約為 250 億歐元; http://www.nytimes.com/2012/10/04/world/europe/safety-review-says-europes-nuclear-reactors-needrepair.html?_r=0

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核四廠重要議題概述2 地震引起的風險 電廠的防震結構措施目前仍未準備充足。核四廠的設計必須特別關注並預期可能發生的強烈地震問 題。 蓄水池在地震後可能因為流失過多水量,無法達到其緊急備用的功能。原子能委員會(AEC)建議 加強這些水池,但在經濟和技術層面上的可行性尚不明確。另外,因地震造成的間接影響也未被考量 到(例如:因管路破裂、火災、非地震防護合格組件的損壞已導致內部淹水),多重裝置損害的問題 亦然。再者,還必須考量到因地震破壞所造成的預期外故障狀況。臺電現有設計,卻是導致須手動 啟用許多位於難以觸及的設備,方能啟用消防用水系統,緊急降溫。且無法並未能保證臺電在取得 運轉執照前,將會對於相關設備依照專家的建議進行設備安全升級。若遭遇地震,燃料儲存池的緊 急冷卻裝置仍不夠堅固。

綠色和平:從福島核災學到的首要教訓是,國家遭受強烈地震襲擊時,最不希望去同時面對的事就

是核能災害。核四廠附近人口密集,這顯現出核四廠是在錯誤的地方採用錯誤的技術。

水災和極端天氣 目前針對海嘯提出的防護措施可能不足,對於海嘯高度預防的設計計算是否適當亦受質疑。防護設 計僅採 100 年降雨造成洪水的重現期為基礎,這顯然不夠,應該要以 10000 年為基礎才恰當。也 沒有針對多重極端天候事件進行分析。在核電廠尚未取得運轉執照前,無法明確得知是否已經實施 建議的升級。 綠色和平:有鑑於複雜的後果,綠色和平認為無論是海嘯或極端天候事件造成的洪水,都會有無法

承受的高風險,因此質疑目前官方所提出的措施並不足以因應。

其他部份議題        

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原子能委員會提出許多「參考」建議,但並未明確指出是否會採行或說明其時程。 核四廠現有設計中並未包含日本和歐盟的進步型沸水式反應器(ABWR)的標準配備,即在洩 壓狀況下防止輻射外洩所需之圍阻體過濾排氣系統,。 原子能委員會並未訂立安裝被動式氫氣再結合器(PAR)的約束,該裝置能在系統意外中斷 時防止氫爆。建議採用此裝置以降低氫爆的風險,進一步防止放射性物質排放到大氣中。 臺灣的設計並不像 歐盟的進步型沸水式反應器( EU-ABWR)具備 爐心補集器 (corecatcher)。 若發生重大事故,大量含有放射性的水極有可能會被排放到海中。 用過燃料儲存池若遭遇嚴重問題時,緊急準備和設備均缺乏且遠低於歐盟的規範標準。 核安管制機構原子能委員會注意到,並無充足的準備以因應多重事故的同時發生(例如同時 涉及兩組反應爐或著單一反應爐與用過燃料池)。 臺電公司或原子能委員會均未提出若發生重大事故時,將如何提供操作人員與其他作業人員 輻射防護,此議題在歐洲備受關注。

詳情請參閱顧問報告:Becker, Oda, Critical Review on the stress tests of the Lungmen nuclear power plant (NPP4) Study commissioned by Greenpeace East Asia; http://www.greenpeace.org/taiwan/Lungmen-Nuclear-Power-

Plant-stress-test-report/ 2


斷然處理措施明顯無法發揮功效,經濟合作暨發展組織(OECD)指出,斷然處置將緊急操 作程序書(EOP)、嚴重事故處理指引(SAMG)、大範圍廠區受損救援指引(EDMG)、 斷然處置程序指引(URG)進行整合,只會導致更多的混亂。

於壓力測試中未突顯的議題      

電廠以日本設計為基礎但採用歐洲和美國的材料建造,其中的差異使得電廠與原始設計有許 多出入。 電廠在建造的過程中,已經有許多安全和品質確保上的缺失。 數位儀控(I&C)系統完全沒有傳統類比硬體線路接線(hard-wired)系統作為後備,這在目 前歐洲和美國的歐洲壓水式反應爐(EPR)中為必要條件。 在初級測試階段,核四的檢測是由一組非獨立於臺電公司(TPC)的團隊進行,這可能導致 系統存在故障但未被揭露。 原子能委員會針對核四廠的建造一直無法進行適當的監督。 核四廠所採用的進步型沸水式反應器(ABWR)設計無法承受大型飛機撞擊。

綠色和平:在壓力測試中沒有將這些複雜的因素視為問題,令人擔憂。只要這些問題仍然存在,無

論如何都不能依據壓力測試的結果「批准」核四廠計畫。

綠色和平關切卻未列入壓力測試中的議題 除了在 Oda Becker 的報告中提出的議題之外,綠色和平也擔憂在評估中沒有列入場外緊急應變和 安全風險的考量(如:恐怖攻擊、網路攻擊、遭受破壞、或發生戰爭),這些項目並沒有列入壓力測 試中。基於核四廠靠近主要人口密集區的考量,這些關鍵問題受到忽視也未獲解決,更讓我們質疑 壓力測試的實質作用。

聯絡人: Jan Haverkamp – 綠色和平核能和能源政策專業顧問:+48 534 236 502,jan.haverkamp@greenpeace.org Rianne Teule – 國際綠色和平核能專家:rianne.teule@greenpeace.org Rashid Kang – 綠色和平東亞區域發展經理:rashid.kang@greenpeace.org

查看核能議題的最新消息和評論: twitter.com/nukereaction 綠色和平是一個獨立的全球性環保組織,致力於以實際行動推動積極的改變,保護地球環境與世界和平。綠色 和平不接受任何政府、歐盟、企業或政治團體的資助。

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Review of the post-Fukushima nuclear stress-tests of the Lungmen nuclear power plant (NPP4) The nuclear regulator of Taiwan announced in 2012 it wanted to carry out nuclear stress tests of its nuclear park on the basis of the post-Fukushima nuclear stress tests carried out in the EU. Like in the EU, Greenpeace asked physicist Oda Becker to carry out an assessment of the stress test reports of a key project for the Taiwanese nuclear programme, the Lungmen nuclear power plant (NPP4). This assessment comes to the sobering conclusion that it would be difficult to backfit the reactor in its current state so that it would meet state of the art risk reduction levels. Furthermore, lack of clarity about the proposed post-Fukushima upgrades should be sufficient reason not forward the project to final licensing. The Fukushima catastrophe was the horrible result of decades of mistaken safety philosophy, a very lax safety regulation under strong industry influence on the regulators – not only in Japan. The first shock led in the EU to the honest wish to change this, to also involve events which are definitely possible but were kept out of the safety cases by using probabilities. In response, the European Union carried out a series of nuclear stress tests, supposed to be a transparent exercise to reduce the risk of nuclear energy in Europe. As a result, the countries with nuclear power stations worked out national action plans to address weaknesses that emerged during the two years of analysis. Greenpeace had these plans assessed and concluded that in spite of significant investments into safety upgrades following the tests3, many vital and known issues are not addressed. Even problems that are being dealt with will take years to be remedied – leaving European citizens exposed to these risks in the meantime. Greenpeace concluded for the EU that where national regulators claimed receiving the highest scores for their stress tests, they intend to let reactors continue to run despite known flaws. The fear of representatives of civil society and independent experts that the stress tests were mainly set up to improve the confidence in the safety of the European nuclear power sector regardless of his findings unfortunately appears to be true. The circumstances under which the nuclear stress-tests are carried out in Taiwan are even further from ideal, and their timing – just before an already announced national referendum on the future of NPP4 – increases the space for PR spin on its results. The analysis carried out by Oda Becker shows that the Taiwanese stress tests of the new Lungmen nuclear project are reason for severe concern. Taken together with the chequered past of the project, her conclusion is that the project is better cancelled. Greenpeace follows that advice and suggests the government of Taiwan cancels the project irrespective of the outcome of the referendum and turns to less dangerous ways to meet its electricity demand, e.g. by energy efficiency measures and renewable energy sources.

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The European Commission estimates the total costs of nuclear upgrades in the EU following the stress-tests at around 25 Billion EUR; http://www.nytimes.com/2012/10/04/world/europe/safety-review-says-europes-nuclearreactors-need-repair.html?_r=0

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An overview of crucial issues with the Lungmen NPP4 Seismic risks There is still insufficient preparedness for beyond design earthquakes. This is of particular concern, because extreme earthquakes have to be expected. The raw water reservoirs might leak too much water after an earthquake to be able to fulfil their function as emergency back-up. Reinforcement of these reservoirs is advised by AEC, but economic and technical feasibility are still unclear. Indirect earthquake effects (internal flooding due to pipe-break, fires, damage to non-seismic qualified components) have not been taken into account, and neither has multi-installation damage. Additionally, unexpected failures as a result of seismic damage have to be expected. Manual actions in difficult to reach parts are still necessary to speed up emergency cooling with the fire water system. There is lack of clarity about whether proposed upgrades have to be implemented before the power station receives its operation license. The emergency cooling for the fuel storage ponds is vulnerable in case of earthquake. Greenpeace: Lesson number one from Fukushima was that when a severe earthquake hits your country, the last thing you want to have to pay attention to is a nuclear catastrophe. Given the dense population surrounding the Lungmen project, it is the wrong technology on the wrong place.

Flooding and extreme weather Current proposed protection measures against potential tsunamis may not be sufficient. There are doubts about the adequacy of the design based tsunami level calculations. There is only protection against precipitation based flooding based on a once in a century rainfall, which is clearly insufficient. Adequate would be a once in 10 000 years. Combinations of extreme weather events have not been analysed. There is lack of clarity about whether proposed upgrades have to be implemented before the power station receives its operation license. Greenpeace: Given the complex consequences, Greenpeace considers the risks of flooding by either tsunami or extreme weather unacceptably high and the proposed responses not sufficient.

Some of the other issues   

    4

The nuclear regulator AEC has given a lot of recommendations “for consideration”, without it being clear whether and when they will be implemented. The design does not know any filtered containment venting system in case of high pressure in spite of the fact that these are standard in the ABWR reactors in Japan and those designed for the EU market. AEC did not issue a binding requirement to install passive autocatalytic hydrogen recombiners to prevent hydrogen explosions in the case there is a system black-out. Measures proposed to reduce the risk of a hydrogen explosion in that case would lead to emissions of radioactivity into the atmosphere. The Taiwan design does not have a core-catcher as in the EU-ABWR. In case of a very large accident, it is likely that large amounts of radioactive water will leak towards the sea. Emergency preparation and equipment in case of severe problems with the spent fuel storage are insufficient and well under the levels required in the EU. Nuclear regulator AEC notices the complete lack of preparedness for a multi-event accident

For details, see the consultants report: Becker, Oda, Critical Review on the stress tests of the Lungmen nuclear power plant (NPP4) - Study commissioned by Greenpeace East Asia;

http://www.greenpeace.org/taiwan/Lungmen-Nuclear-Power-Plant-stress-test-report/ 5


 

(for instance involving two reactors or a reactor and spent fuel pool). Neither the Taiwan Power Corporation nor AEC addresses the radiation protection of operators and all other staff in case of a severe accident, an issue that received a lot of attention in Europe. The Urgent Response Guidelines are clearly insufficient, and there exists concern, among others voiced by the OECD, that the proposed integration of emergency operating procedures (EOPs), severe accident management guidelines (SAMGs), and extensive damage mitigation guidelines (EDMGs) with the ultimate response guidelines (URGs) will lead to more confusion.

Issues not highlighted in the stress tests      

There are relatively much diversions from the original plant design because of differences between the Japanese design base and the use of European and US materials. There have been many lapses of safety culture and quality insurance during the construction of the plant. There is no hard-wired system back-up for the completely digital I&C system, as is now required in the EPR reactors in Europe and the US. In the primary testing stage, the Lungmen NPP was tested by a team that was not independent from TPC, which could lead to system failures going undiscovered. AEC was and is insufficiently equipped to properly oversee the construction of Lungmen. The ABWR design used in Lungmen is not prepared for large aircraft impact.

Greenpeace: That these issues were not taken up in the stress test as complicating factors is worrying. If only because of these non-addressed outstanding issues, the stress tests can certainly never be used to give Lungmen any form “approval”.

Issues of concern to Greenpeace not addressed in the stress tests Next to the issues raised in the report of Oda Becker, Greenpeace also has major concerns about the fact that like in the EU stress tests, off-site emergency response and security risks (terrorist attacks, cyber-attacks, sabotage, acts of war) have not been included in the assessment. Given the close distance of the Lungmen NPP to major population concentrations, Greenpeace finds these omissions unacceptable.

Contacts: Jan Haverkamp – Greenpeace expert consultant on nuclear energy and energy policy: +48 534 236 502, jan.haverkamp@greenpeace.org Rianne Teule – Greenpeace International, nuclear campaigner: rianne.teule@greenpeace.org Rashid Kang – Greenpeace East Asia, regional development manager: rashid.kang@greenpeace.org

For breaking news and comment on nuclear issues:

twitter.com/nukereaction

Greenpeace is an independent global campaigning organisation that acts to change attitudes and behaviour, to protect and conserve the environment and to promote peace. Greenpeace does not accept donations from governments, the EU, businesses or political parties.

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