核技術(shù)導(dǎo)論英文課件：Chapter 7 Nuclear Waste

1、Chapter 7. Nuclear WasteNuclear Waste Disposal: Amounts of Waste Categories of Nuclear Waste Wastes from Commercial ReactorsHazard Measures for Nuclear Wastes 2. Storage and Disposal of Nuclear Wastes Stages in Waste HandlingDeep Geologic DisposalAlternatives to Deep Geologic DisposalWorldwide Statu

2、s of Nuclear Waste Disposal Plans城市放射性廢物管理辦法IAEA Safety Standards: Geological disposal of radioactive waste 1.1 Categories of Nuclear WasteThe Nature of the ProblemMilitary and Civilian WastesWastes from commercial nuclear reactors raise more critical issues the amounts are greater, their production

3、 continuesFormHalf lifetimeRadioactivity levelAs with all radioactive sources, radioactive waste is potentially hazardous to health. Therefore, it must be managed in a safe way to protect people and the environmentGood waste management begins before the wasteis generated: the starting point for all

4、activities that produce radioactive waste is to avoid or reduce waste generation at its source. Minimizing primary waste generation also minimizes the quantity of waste requiring disposal.Bad News: Wastes from commercial nuclear reactors raise more critical issues the amounts are greater, their prod

5、uction continuesGood News: The world has over half a centurys knowledge and experience on how to deal with nuclear waste. When the characteristics of the waste are known, it can be managed. -IAEATypes of WasteHigh-level waste (HLW)Transuranic waste (TRU)Low-level waste (LLW)Uranium Mill TailingsThis

6、 categorization varies slightly from country to country, but in principle the main criteria for determining the type of waste are derived from radioactive content and half-life, i.e. the time taken for the waste to lose half of its radioactivity.Types of WasteHigh-Level WasteThe most dangerous radio

7、active wasteSpent fuel comes from nuclear reactors (52,000 tons) liquid and solid waste from plutonium production (91 million gallons).About 70 percent of the available storage space is now filled with used fuel assemblies at Turkey Point. Types of WasteTransuranic WasteIncludes clothing, tools, and

8、 other materials contaminated with plutonium, neptunium, and other man-made elements heavier than uranium. Types of WasteLow and Mixed Low-Level WasteIncludes radioactive and hazardous wastes from hospitals, research institutions, and decommissioned power plants (472 million cubic feet)Uranium Mill

9、TailingsResidues left from the extraction of uranium ore (265 million tons).Types of Waste MiningUranium ore is usually located aerially; core samples are then drilled and analyzed by geologists. The uranium ore is extracted by means of drilling and blasting. Mines can be in either open pits or unde

10、rground. Uranium concentrations are a small percentage of the rock that is mined, so tons of tailings waste are generated by the mining process. Production in 2000Canada 10,682 Australia 7,578 Niger 2,895 Namibia 2,714 Uzbekistan 2,350 Russia (est) 2,000 Kazakhstan 1,752 USA 1,456 South Africa 878 C

11、hina (est) 500 Ukraine (est) 500 Czech Republic 500 India (est) 200 France 319 others 422 Total world 34,746 companytonnes UCameco7218Cogema 6643WMC3693ERA 3564Navoi 2400Rossing2239KazAtomProm2018Priargunsky2000Source: /search/index.htm Whatever the type of the radioactive waste, all of it has to be

12、 disposed of in a safe manner!It is a common misbelief that radioactive waste takes up a lot of space. However, all the spent fuel generated by two 860 MW reactors during their 40 years of operation would fit into three 10 metre by ten metre pools.Measures of Waste MagnitudesMass: The most common ma

13、ss measure for nuclear waste is the mass of the uranium in the initial fuel, more broadly designated as metric tonnes of initial heavy metal (MTIHM or MTHM)Volume: The volume of the fuel can be inferred from the UO2 mass and density (about 10 tonnes/m3).Radioactivity: in terms of the activity (in cu

14、ries or becquerels) taken either for the radionuclides individually or for their sum. radionuclides differ in the types of particles emitted, their energy, the half-lives, and the possibility of their reaching thebiosphere. Nonetheless, it provides some overall perspective.Heat output: on the scale

15、of 6 kW of heat are produced per megacurie of activity1.2 Wastes from Commercial ReactorsMass and Volume per GWyrActivity of selected radionuclides in spent fuel versus time since discharge of fuel from reactorActivity of selected radionuclides as a function of timeHeat ProductionThe handling of the

16、 nuclear wastes is significantly complicated by the heat generated in the decay of the radionuclidesThe heat generation per unit activity depends on the energy carried by the emitted particles.1 megacurie 5.93 kW (at 1 MeV per disintegration).Decay of spent fuel from 1 GWyr of PWR operation, for bur

17、nup of 40 GWd/t (28.5 MTHM): activity and thermal output as a function of time since discharge.1.3 Hazard Measures for Nuclear WastesTotal System Performance Assessments (TSPAs)The maximum permissible concentration is established as the maximum level acceptable for drinking wateris closely related t

18、o the annual limit on intake (ALI). 20 mSv/yrThe water dilution volume (in cubic meters) is the amount of water required to dilute the radionuclide to the maximum permissible concentration.Illustration of use of water dilution volume: WDV of radionuclides in PWR spent fuel, as a function of timeChap

19、ter 7. Nuclear WasteNuclear Waste Disposal: Amounts of Waste Categories of Nuclear Waste Wastes from Commercial ReactorsHazard Measures for Nuclear Wastes 2. Storage and Disposal of Nuclear Wastes Stages in Waste HandlingDeep Geologic DisposalAlternatives to Deep Geologic DisposalWorldwide Status of

20、 Nuclear Waste Disposal PlansWaste Storage AlternativesLeave It Where It IsDeep Geologic DisposalYucca Mountain, NevadaSalt Cave DisposalWIPP near Carlsbad, New MexicoVery Deep Holes (6 miles)Ice-Sheet DisposalSpace DisposalSub-Seabed DisposalIsland Geologic DisposalDeep-Well Injection DisposalVitri

21、fication (Glass Waste)ReprocessingIt is better to have used nuclear fuel in one locationNIMBY: Not In My Back YardFear of radiation because they dont understand itConcern that the waste facility willrelease long-term contaminationWorry that property values will be reducedwith construction of a waste

22、 facilityBelief that power companies are the ones responsible for storing their own wastePeople dont want dumped on by otherpeoples wasteBelief that nuclear power should just goaway and be replaced by other energyresourcesEnvironmental concernsCurrent Waste DisposalAt this time, radioactive wastes a

23、re being stored at the Department of Energys facilities around the country High level wastes are stored in underground carbon or stainless steel tanksSpent nuclear fuel is put in above-ground dry storage facilities and in water-filled pools Current High-Level Waste Storage in the US2.2 Deep Geologic

24、 DisposalIn every option, deep geological disposal is the preferred final end point.The principle of geological disposal is to isolate the waste deep inside a suitable host formation, e.g. granite（花崗巖）, salt or clay.The waste is placed in an underground facility or disposal facility, designed to ens

25、ure that a system of natural and multiple artificial barriers work together to prevent radioactivity from escaping.Yucca MountainThe Future of Nuclear Waste StorageYucca Mountain Project: Nuclear Fuel and High Level Waste RepositoryMuch more secure repository than leaving high level waste at 60 reac

26、tor sites around the country.On old atomic bomb testing base, inside a mountain.The storage is above the water table.The Yucca Mountain site would be 60% filled by present waste.US has legal commitment to the reactor industry.Site has been studied extensively by scientists for over 20 years.Will sto

27、re waste during its 10,000 year decay time.Questions of how to deflect dripping water around and under the storage vessels.Questions of radioactive decay weakening storage containers.A solution would be to build containers that can be opened and reincased, or to which surrounded casings could be add

28、ed.Transportation ConcernsArtists conception of transportation cask and carrier for truck transport;total length = 18 m (56 ft).Typical Low-Level Waste Disposal SiteHanford (Nuclear News, November 2004)CountryFacility name / RegionGeologyDepthStatusBelgiumHADES Underground Research Facility / Molpla

29、stic clay223 min operation 1982CanadaAECL Underground Research Laboratory / Pinawagranite420 m1990-2006FinlandONKALO/Olkiluotogranite400 munder constructionFranceMeuse/Haute Marne Underground Research Laboratory/ Buremudstone500 min operation 1999JapanHoronobe Underground Research Lab /Horonobesedim

30、entary rock500 munder constructionJapanMizunami Underground Research Lab /Mizunamigranite1000 munder constructionKoreaKorea Underground Research Tunnelgranite80 min operation 2006SwedenAspo Hard Rock Laboratorygranite450 min operation 1995SwitzerlandGrimsel Test Sitegranite450 min operation 1984Swit

31、zerlandMont Terri Rock Laboratory / Mont Terriclaystone300 min operation 1996USAYucca Mountain nuclear waste repository/ Nevadatuff,ignimbrite50 m1997-20082.4 Worldwide Status of Nuclear Waste Disposal PlansKoreaGyeongjuL&ILW80 munder constructionSwedenSFR / Forsmark63,000 m3L&ILWgranite50 min opera

32、tion 1988SwedenForsmarkspent fuelgranite450 mlicence application 2011Switzerlandhigh-level wasteclaysitingUnited Kingdomhigh-level wasteunder discussionUSAWaste Isolation Pilot Plant/ New Mexicotransuranic wastesalt bed655 min operation 1999USAYucca Mountain Project/ Nevada70,000 ton HLWignimbrite20

33、0-300 mproposed, canceled 2010高放廢物地質(zhì)處置研究開發(fā)規(guī)劃指南國 防 科 學(xué) 技 術(shù) 工 業(yè) 委 員 會科 學(xué) 技 術(shù) 部國 家 環(huán) 境 保 護(hù) 總 局 2006我國高放廢物地質(zhì)處置規(guī)劃研究的總體思路是：統(tǒng)籌規(guī)劃、協(xié)調(diào)發(fā)展、分步?jīng)Q策、循序漸進(jìn)。研究開發(fā)和處置庫工程建設(shè)包括三個階段：試驗室研究開發(fā)和處置庫選址階段（20062020）、地下試驗階段（20212040）、原型處置庫驗證與處置庫建設(shè)階段（2041本世紀(jì)中葉）甘肅北山3個預(yù)選地段（舊井、野馬泉、向陽山-新場）北山完整的花崗巖體安全評價安全標(biāo)準(zhǔn)數(shù)據(jù)庫程 序場址特征地質(zhì)穩(wěn)定性、地震安全性水文地質(zhì)、地球化學(xué)工程地質(zhì)、巖石、裂隙深部地質(zhì)環(huán)境未來變化地學(xué)信息庫. 工程設(shè)計開挖技術(shù)硐室穩(wěn)定性工程布局、間隔膨潤土、廢物罐工程經(jīng)濟(jì).核素遷移特征巖石力學(xué)工程屏障膨潤土廢物罐景象開發(fā)后果分析不確定分析高放廢物地質(zhì)處置的主要內(nèi)容框架 高放廢物地質(zhì)處置：科學(xué)挑戰(zhàn) 處置庫中的廢物：放射性強(qiáng)毒性大半衰期長處置庫的安全評價期至少要達(dá)到1萬年。 這一要求是前任何工程所沒有的。 并且要求有科學(xué)、可信的手段評價處置庫是 安全的核工業(yè)北京地質(zhì)研究院，Beijing Research Institute of Uranium GeologyIn terms