Chapter 7. Nuclear Waste

1.Nuclear Waste Disposal: Amounts of Waste Categories of Nuclear Waste

Wastes from Commercial Reactors

Hazard Measures for Nuclear Wastes

2. Storage and Disposal of Nuclear Wastes Stages in Waste Handling

Deep Geologic Disposal

Alternatives to Deep Geologic Disposal

Worldwide Status of Nuclear Waste Disposal Plans

城市放射性废物管理办法

IAEA Safety Standards: Geological disposal of radioactive waste

1.1 Categories of Nuclear Waste

The Nature of the Problem

Military and Civilian WastesWastes from commercial nuclear reactors raise more critical issues the amounts are greater, their production continues…

FormHalf lifetimeRadioactivity level

As 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 environment

Good waste management begins before the wasteis generated: the starting point for all 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 production continues…

Good News: The world has over half a century’s knowledge and experience on how to deal with nuclear waste. When the characteristics of the waste are known, it can be managed. -IAEA

Types of Waste

• High-level waste (HLW)• Transuranic waste (TRU)• Low-level waste (LLW)• Uranium Mill Tailings

This 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 Waste

•High-Level Waste•The most dangerous radioactive waste•Spent 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 Waste

Transuranic Waste

– Includes clothing, tools, and other materials contaminated with plutonium, neptunium, and other man-made elements heavier than uranium.

Types of Waste

• Low and Mixed Low-Level Waste

– Includes radioactive and hazardous wastes from hospitals, research institutions, and decommissioned power plants (472 million cubic feet)

Uranium Mill Tailings•Residues left from the extraction of uranium ore (265 million tons)).

Types of Waste

 

Mining• Uranium 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 underground. 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 2000

Canada 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

China (est) 500

Ukraine (est) 500

Czech Republic 500

India (est) 200

France 319

others 422

Total world 34,746

company tonnes U

Cameco 7218

Cogema 6643

WMC 3693

ERA 3564

Navoi 2400

Rossing 2239

KazAtomProm 2018

Priargunsky 2000

Source: http://www.world-nuclear.org/search/index.htm

Whatever the type of the radioactive waste, all of it has to be 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 Magnitudes

Mass: The most common mass 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 curies 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 of 6 kW of heat are produced per megacurie of activity

1.2 Wastes from Commercial Reactors

Mass and Volume per GWyr

Activity of selected radionuclides in spent fuel versus time since discharge of fuel from reactor

Activity of selected radionuclides as a function of time

Heat Production

The handling of the nuclear wastes is significantly complicated by the heat generated in the decay of the radionuclides

The 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 burnup 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 water

is closely related to the annual limit on intake (ALI). 20 mSv/yr

The 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 time

Chapter 7. Nuclear Waste

1.Nuclear Waste Disposal: Amounts of Waste Categories of Nuclear Waste

Wastes from Commercial Reactors

Hazard Measures for Nuclear Wastes

2. Storage and Disposal of Nuclear Wastes Stages in Waste Handling

Deep Geologic Disposal

Alternatives to Deep Geologic Disposal

Worldwide Status of Nuclear Waste Disposal Plans

Waste Storage Alternatives

• Leave It Where It Is• Deep Geologic Disposal

– Yucca Mountain, Nevada• Salt Cave Disposal

– WIPP near Carlsbad, New Mexico• Very Deep Holes (6 miles)• Ice-Sheet Disposal• Space Disposal• Sub-Seabed Disposal• Island Geologic Disposal• Deep-Well Injection Disposal• Vitrification (Glass Waste)• Reprocessing

It is better to have used nuclear fuel in one location

NIMBY: Not In My Back Yard

• Fear of radiation because they don’t understand it• Concern that the waste facility will

release long-term contamination• Worry that property values will be reduced

with construction of a waste facility• Belief that power companies are the ones

responsible for storing their own waste• People don’t want dumped on by other

peoples’ waste• Belief that nuclear power should just go

away and be replaced by other energyresources

• Environmental concerns

Current Waste Disposal

• At this time, radioactive wastes are being stored at the Department of Energy’s facilities around the country

• High level wastes are stored in underground carbon or stainless steel tanks

• Spent nuclear fuel is put in above-ground dry storage facilities and in water-filled pools

Current High-Level Waste Storage in the US

www.nei.org

2.2 Deep Geologic Disposal

In 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（花岗岩） , salt or clay.

The waste is placed in an underground facility or disposal facility, designed to ensure that a system of natural and multiple artificial barriers work together to prevent radioactivity from escaping.

Yucca Mountain

The Future of Nuclear Waste Storage

Yucca Mountain Project: Nuclear Fuel and High Level Waste Repository

Much more secure repository than leaving high level waste at 60 reactor 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 store 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 added.

Transportation Concerns

Artist’s conception of transportation cask and carrier for truck transport;total length = 18 m (56 ft).

Typical Low-Level Waste Disposal Site

Hanford (Nuclear News, November 2004)

Country Facility name / Region Geology Depth StatusBelgium HADES Underground Research Facility

/ Molplastic clay 223 m in operation 1982

Canada AECL Underground Research Laboratory / Pinawa

granite 420 m 1990-2006

Finland ONKALO / Olkiluoto granite 400 m under construction

France Meuse/Haute Marne Underground Research Laboratory

/ Bure

mudstone 500 m in operation 1999

Japan Horonobe Underground Research Lab / Horonobe

sedimentary rock

500 m under construction

Japan Mizunami Underground Research Lab / Mizunami

granite 1000 m under construction

Korea Korea Underground Research Tunnel granite 80 m in operation 2006

Sweden Aspo Hard Rock Laboratory granite 450 m in operation 1995

Switzerland Grimsel Test Site granite 450 m in operation 1984

Switzerland Mont Terri Rock Laboratory / Mont Terri

claystone 300 m in operation 1996

USA Yucca Mountain nuclear waste repository / Nevada

tuff, ignimbrite 50 m 1997-2008

2.4 Worldwide Status of Nuclear Waste Disposal Plans

Korea Gyeongju L&ILW — 80 m under construction

SwedenSFR /

Forsmark63,000

m3 L&ILWgranite 50 m in operation 1988

Sweden Forsmark spent fuel granite 450 m licence application 2011

Switzerland

—high-level

wasteclay — siting

United Kingdom

—high-level

waste— — under discussion

USA

Waste Isolation Pilot Plant / New

Mexico

transuranic waste

salt bed 655 m in operation 1999

USA

Yucca Mountain Project / Nevada

70,000 ton HLW

ignimbrite 200-300 m proposed, canceled 2010

高放废物地质处置研究开发规划指南

国防科学技术工业委员会 科 学 技 术 部 国 家 环 境 保 护 总 局

2006

我国高放废物地质处置规划研究的总体思路是：统筹规划、协调发展、分步决策、循序渐进。

研究开发和处置库工程建设包括三个阶段：试验室研究开发和处置库选址阶段（ 2006 － 2020）、地下试验阶段（ 2021 － 2040）、原型处置库验证与处置库建设阶段（ 2041－本世纪中叶）

甘肃北山 3个预选地段（旧井、野马泉、向阳山 -新场）

In terms of good practices of radioactive waste management, responsibility covers all the steps from ‘cradle to grave’.

Energy Source Death Rate  deaths per TWhr deaths per GWyr  

Coal – world average 161 1410 (26% of world energy, 50% of electricity)

Coal – China 278 2435  Coal – USA 15 131  Oil 36 315 (36% of world energy)

Natural Gas 4 35 (21% of world energy)

Biofuel/Biomass 12 105  Peat 12 105  

Solar (rooftop) 0.44 3.85 (less than 0.1% of world energy)

Wind 0.15 1.31 (less than 1% of world energy)

Hydro 0.10 .88 (europe death rate, 2.2% of world energy)

Hydro - world including Banqiao)

1.4 12 (about 2500 TWh/yr and 171,000 Banqiao dead)

Nuclear 0.04 .35 (5.9% of world energy)

Living is not a risk-free endeavour to be sure.

Chapter 7. Nuclear Waste

1.Nuclear Waste Disposal: Amounts of Waste Categories of Nuclear Waste

Wastes from Commercial Reactors

Hazard Measures for Nuclear Wastes

2. Storage and Disposal of Nuclear Wastes Stages in Waste Handling

Deep Geologic Disposal

Alternatives to Deep Geologic Disposal

Worldwide Status of Nuclear Waste Disposal Plans

Oriel Wilson, Raquel R. Pinderhughes,Dennis Silverman, Lindsey GarstJay Nargundkar, Jonah Richmond