Radioactive waste management ppt

ASSIGNMENT-1 ASSIGNMENT-1 This ppt is presented by:-This ppt is presented by:-

ADITYA KUMAR SAHUROLL NO:-411PH5082

INTEGRATED MSc. IN PHYSICSNIT,ROURKELA

Nuclear Waste Nuclear Waste DisposalDisposal

Aditya kumar sahuAditya kumar sahu

Nuclear Waste…Why?Nuclear Waste…Why?

•Recently nuclear power has entered many discussions as

world energy needs rise and oil reserves diminish.

•Most opponents of nuclear power point to two main

arguments: meltdowns and nuclear waste.

•Nuclear waste is any form of byproduct or end product that

releases radioactivity.

•How to safely dispose of nuclear waste is pivotal for the

continued operation of nuclear power plants, safety of people

living around dump sites, and prevention of proliferation of

nuclear materials to non-nuclear states

Nuclear Fuel Cycle

Most nuclear waste comes from the byproducts of the nuclear fuel cycle. The cycle typically is split into three sections: front end, service period, and back end. There can be intermediate stages that include the reprocessing of nuclear waste elements.

Nuclear Fuel Cycle (Cont.)Nuclear Fuel Cycle (Cont.)

Radioactive WasteRadioactive Waste

We will discuss -Low Level Radioactive WasteHigh Level Radioactive WasteMining Tailings

ClassificationsClassificationsNuclear waste is segregated into several

classifications.Low level waste is not dangerous but

sometimes requires shielding during handling. Intermediate level waste typically is chemical

sludge and other products from reactors.High level waste consists of fissionable

elements from reactor cores and transuranic wastes.

Transuranic waste is any waste with transuranic alpha emitting radionuclides that have half-lives longer than 20 years.

Low level waste is any waste that could be from a high activity area.

90% volume of wasteIt does not necessarily carry any

radioactivity.Split into four catagories: A, B, C, and

GTCC.

Low Level WasteLow Level WasteLLWLLW

Intermediate Level WasteIntermediate Level WasteILWILW

Intermediate level waste requires shielding when being handled.

7% volume of wasteDependent on the amount of activity it can

be buried in shallow repositories. Not recognized in the United States.

High Level WasteHigh Level WasteHLWHLW

High level waste has a large amount of radioactive activity and is thermally hot.

3% volume of waste95% of radioactivityCurrent levels of HLW are increasing about

12,000 metric tons per year.Most HLW consists of Pu-238, 239, 240,

241, 242, Np-237, U-236

Transuranic WasteTransuranic WasteTRUWTRUW

Transuranic waste consists of all waste that has radionuclides above uranium.

TRUWs typically have longer half-lives than other forms of waste.

Typically a byproduct of weapons manufacturing.

Only recognized in the United States.

Creation of Nuclear WasteCreation of Nuclear Waste•Nuclear waste is generated at all points of the fuel cycle.•Front end waste consists primarily of low level alpha emission waste.•Service period waste typically includes LLW and ILW such as contaminated reactor housings and waste from daily operation.•Back end waste normally is the most radioactive and includes spent fuel rods and reactor cores.

Front End WasteFront End Waste

Front end waste consists mostly of LLW and ILW.

The primary front end waste is depleted uranium and radium. – DU has several uses due to its high density

(19,050 kg/m3).– Mix with uranium to form reactor fuel

Service Period WasteService Period Waste

Consists of mostly ILW.Mostly waste produced at the plant during

normal operation.Spent fuel rods are the most dangerous

waste produced during the service period.

Back End WasteBack End Waste

Nuclear waste developed during the back end of the fuel cycle is the most dangerous and includes most of the HLW produced.

Most back end waste emits both gamma and beta particles.

Also uranium-234, neptunium-237, plutonium-238 and americium-241are found in back end waste.

Spent nuclear fuel in a cooling pond in NorthKorea.

Low Level Radioactive WasteLow Level Radioactive Waste

Low Level Radioactive waste consists of microcurie, millicurie and at times curie activity waste.

(A Curie is a unit of nuclear transformations. 1 Curie is 3.7 x1010 transformations per second)

Low Level Radioactive WasteLow Level Radioactive Waste

Low level radioactive waste consists of:– Contaminated solids– liquids– animal carcasses– small sealed sources

There are several options available for the disposal of LLW due to its lack of radioactivity.

Waste Isolation Pilot Plant

On-site disposal

Waste Management (LLW)Waste Management (LLW)

Map of WIPP Facility


Low level radioactive liquids are either:– Incinerated– Deep well injected (not as frequent anymore)– Solidified– Sewer Disposed (Regulations allow curie levels

of some isotopes to be sewer disposed of if dilution is large enough)


Radioactive animal carcasses are either incinerated or buried onsite.


Small sealed sources are “Stabilized” in concrete and buried. Stabilized concrete is concrete that is certified to resist wear for a certain time period.


Low level contaminated solid wastes are buried. GSU has it’s solid waste “Supercompacted” at 30,000 psi to reduce the volume to be buried


Most low level wastes come from Government and Utilities. These consist of contaminated solids from nuclear reactor usage and weapon construction.


Colleges, research and medical applications account for less than 25% of the low level Radioactive wastes created


Class A low-level radioactive waste is the least hazardous, containing mostly short-lived radionuclides that will be reduced in radioactivity (decay) in a relatively short time. It contains only small amounts of radionuclides that take a relatively short time to decay. Class A waste will be disposed of in concrete canisters that will maintain their shape and strength for hundreds of years.


Class B low-level radioactive waste is more hazardous than Class A waste. Most of it comes from nuclear reactors. It must be in a stable form for disposal and will also be disposed of in concrete canisters. Stabilization can be accomplished by solidifying liquid waste, compacting solid waste, or placing the low-level radioactive waste in a container that will be stable for many years. Class B low-level radioactive waste makes up only a small percent of the waste volume generated; but along with Class C waste, it contains the largest portion of the total radioactivity.


Class C low-level radioactive waste is the most hazardous and must be handled accordingly. It also must be disposed of in a stable form.


There are 3 LLRW Burial sites:– Hanford– Envirocare– Barnwell


Politics of LLRW– Compacts– On-site burial– NIMBY


The compact system was set up by NRC to have all states share in the responsibility of disposal of radioactive waste and to limit waste transport distance. Georgia is in the Southeast compact.

Until 1992, all states within the SE compact (excluding Florida) would host a LLRW landfill on a 20-25 year revolving timetable.


Kentucky was the first (Maxie Flats), then South Carolina (Barnwell). In 1995, North Carolina was to open a site but the citizens protested and sued. The State legislature refused.

North Carolina was then “kicked out” of the S.E. compact and left with no place to dispose of waste. Other States followed N.C.’s lead and refused

This lead to the collapse of the traditional compact system and the


In the past, many Universities and companies were allowed to bury their radioactive wastes onsite. Some were allowed to deep well inject liquid radioactive waste.


N.I.M.B.Y.

Not

In

My

Back

Yard

The true politics of Hazardous Waste

Fear of radiation because they don’t understand it

Concern that the waste facility willrelease long-term contamination

Worry that property values will be reducedwith 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 otherpeoples’ waste

Belief that nuclear power should just goaway and be replaced by other energyresources

Environmental concerns

NIMBY: Not In My Back YardNIMBY: Not In My Back Yard

Low-Level Low-Level Disposal SitesDisposal Sites

Typical Low-Level Waste Typical Low-Level Waste Disposal SiteDisposal Site

Hanford (Nuclear News, November 2004)

Treatment (LLW)Treatment (LLW)

FiltrationIon ExchangeEvaporationIncinerationCompactionSolidification

Typical LLW treatment facility.

Waste Management (HLW)Waste Management (HLW)

Most common utilized option are reactor pools and dry cask storage.

Other Options for waste management include:– Deep Geologoical

Storage– Transmutation– Reuse– Launching it into space

Locations of storage sites for nuclear waste in the U.S.

High-Level Radioactive WasteHigh-Level Radioactive Waste

High-Level Radioactive Waste is: the irradiated fuel from the cores of nuclear reactors, the liquid and sludge wastes that are left over after irradiated fuel has been reprocessed (a procedure used to extract uranium and plutonium), the solid that would result from efforts to solidify that liquid and sludge from reprocessing.


Because there is currently no high level radioactive waste disposal facility, HLRW is held On-Site in water pools

Radioactive WasteRadioactive WasteOnce these

Pools are full, Waste is transferred to casks which are also held on-site


A HLRW repository is being constructed at Yucca Mountain in Nevada to hold all this waste. NIMBY again is playing a role in the opening

Current High-Level Waste Current High-Level Waste Storage in the US Storage in the US

www.nei.org

Transportation ConcernsTransportation Concerns

TreatmentTreatment

Most common initial treatment of waste is vitrification.– Waste is first mixed with sugar and then passed

through a heated tube to de-nitrite the material.– This material is then fed into a furnace and

mixed with glass.– The molten glass mixture is poured into steel

cylinders and welded shut.

Treatment (Cont.)Treatment (Cont.)

Mid level active waste is commonly treated with ion exchange

Process reduces the bulk volume of radioactive material.

Typically, mixed with concrete for a solid storage form.

Deep Geological RepositoryDeep Geological Repository

Most common method for handling nuclear waste.

Typically kept separate from actual plants and buried far below ground.

First used in 1999 in the US.

Current research is focusing on Yucca Mountain. Yucca Mountain Site

Transmutation of Nuclear Transmutation of Nuclear WasteWaste

Reduces transuranic waste. Integral Fast ReactorBanned 1977-1981 (U.S.)MOX Fuel

– Behaves as low-enriched uranium

Research now in subcritical reactors.Fusion also being researched.

Reuse of Nuclear WasteReuse of Nuclear Waste

Research is being performed to find uses for nuclear waste.

Caesium-137 and strontium-90 already used in industrial applications.

Some waste can be used for radioisotope thermoelectric generators (RTGs).

Overall can reduce total HLW but not eliminate it.

Launch it into SpaceLaunch it into Space

Near infinite storage space

Completely removes waste from biosphere

Technical risks and problems

Political entanglements

Yucca MountainYucca Mountain

For more information, http://www.ocrwm.doe.gov/ymp/index.shtml

Yucca Mountain• Technically sound

• 1,000’ below

ground

• Repository in block

of solid rock

• 1,000’ above water

table

• Remote location on Nevada

Test Range

It is better to have used nuclear fuel in one location

Deep Geologic RepositoryDeep Geologic Repository

Built forBuilt for300 years of retrieval300 years of retrieval

10,000 years of storage10,000 years of storage

Waste IsolationWaste IsolationPilot PlantPilot Plant

Opened March 26, 1999 Storage of transuranic

waste leftover from research an production of nuclear weapons

http://www.wipp.energy.gov/

http://www.radiochemistry.org/wipp_tour/index.html

Private Fuel StoragePrivate Fuel Storage(Skull Valley, Utah)(Skull Valley, Utah)

Temporary storage of spent nuclear fuel until Yucca Mountain is operational

Goshute Indian Skull Valley Band

3-ft thick concrete storage pads

http://www.privatefuelstorage.com/ http://www.kued.org/skullvalley/

ConclusionsConclusions

HLW is most dangerous byproduct of nuclear power.

Borosilicate glass most common storage.

Several venues being researched for the safe disposal of HLW.

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Radioactive waste management ppt

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