Lessons learned from nuclear decommissioning projects · 9/11/2012  · Some lessons learned from...

Lessons learned from nuclear decommissioning projects11 September 2012

Studsvik in brief• Founded 1947

• A world wide supplier of nuclear services

• Development of the Swedishnuclear program

• Net sales €150M, 1,200 employees

• Offices in 7 countries - Major operation in Sweden, Germany, UK and USA

• Major products and services:

– Materials testing, hot cells

– Fuel and core software

– Engineering, consulting and maintenance services

– Waste Treatment and D&D

Studsvik decommissioning experience

Participation in decommissioning of:

•BWR and PWR power plants

•Research reactors and other researchfacilites

•Fuel manufacturing plants

•Uranium mines and uranium extraction plants

•Military weapons facilities

Obrigheim high pressure turbine before dismantling

After dismantling

Important general parameters in D&DSimilar to any large project

• Planning

• Experience, competence and understanding

• Structure and logistics, do things in the right order

• Effective and robust processes

• Close co-operation

Some lessons learned from D&D• Plan for an early start – Plant knowledge will

disappear over time

• Implement waste led decommissioning.Waste is ~1/3 of total cost

• Characterize waste – Develop clear objectives

• A well structured categorization is a basis forgraded approach in clearance

• Off site waste treatmentsaves time and money

Characterisation

Categorisation

Rip, Pack

and Ship

Waste

treatment

Radwaste

minimisation

Waste management – key stones

Decommissioning waste management – the Studsvik concept

Time is critical - Rip and Ship

On Site

Off Site

Rip & Ship Concept

• Minimize calendar time for decommissioning (Increased efficiency and decreased cost)

• Remove decontaminated waste early in the process to a Centralized facility (Parallel operation, Storage if necessary)

• ”Transform” the nuclear site to a more standard demolition site (Easy access and operation, Increased safety)

• Maximize volume reduction and recycling (Best in class environmentally, Reduced final disposal)

• Ensure optimized packaging of waste for final disposal (Reduced volume for final disposal)

Transport and handling

Two types of transports:

•In ISO freight containers (mainly loaded with boxes)

•Large components

Two major transport alternatives:

•Truck

•Ship

Environmental aspectsMaximize waste volume reduction

• Direct free release + Reuse/recycling of material

• Decontamination and free release+ Recycling of valuable material

• Incineration+ Energy recovery

• Compacting and packing+ Minimize waste volume

for final repositoryAvoid/

Minimise ReuseRecycle

Energy recovery Dispose

IncinerationDry combustible waste

• 97 % volume reduction

• 92 % weight reduction

• Ash – Stable end product

• Customer specific campaigns

Arrival inpection & sorting

Incinerator

Secondary waste ~ 3 %

Weight/Dosrate

Heat recovery

SecondaryWaste

Volume reduction & recycling Containerized scrap metal

• Volume reduction and recycling• Steel, brass, copper, aluminium & lead• Decont. by blasting & melting

Sorting Segmentation

Blasting

Melting

Slag crushing

Free release> 95 %

Arrival inspection

A

B

C

SecondaryWaste

Volume reduction & recycling Large Components (BWR)

Segmentation

Blasting

Melting

Crushing (slag)

Arrival inspection

SecondaryWaste

Ingots

Free release> 95 %

• Volume reduction and recycling• Segmentation• Decont. by blasting & melting

Steam Generator Treatment Secondarywaste

Tube pullingBand saw

Blasting chamberTube blasting

Melting

Arrivalinspection

Separation of steam dome

Repository

SecondaryWaste Return

Free release~90 % volume~80% weight

Studsvik waste management large components - examples

170t HX, NPP Oskarshamn (Swe)

Turbine componentsNPP Würgassen (Ger)

700t Turbine componentsNPP Ringhals (Swe)

300t Turbine componentsNPP Mühleberg (Ch)

1600t TurbinesNPP Forsmark (Swe)

8x88t HX, TVO (Fini)

9 x 310t Steam GeneratorsRinghals (Swe)

4 x 165t Steam GeneratorsNPP Stade (Ger)

5 x 300t BoilersBerkeley Magnox (UK)

Experience can be developed and reducecost and time

Example from Studsvik SG treatment:

Year Processing time

2005 SG1 18 months

2006-7 SG 2-4 6-8 months

2008-10 SG 5-10 4-6 months

2011-12 SG 11- 3-4 months SG

’str

eate

dpe

r ye

ar

Key areas for safe and low costdecomissioning

• Regulatory harmonization– Decomissioning– Waste treatment– Free release

• International cooperation

• Transparant planning

• Minimize waste

• Development of technologiesand facilities

• Standardization

• Best practices

• Capacity

• Resources

Questions?