ALARA STUDIES FOR EDF NUCLEAR POWER PLANTS

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ALARA STUDIES FOR EDF NUCLEAR POWER PLANTS
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Presentation draft

• EDF and UTO presentation
• From PANTHER-RP simulation tool to practical
  recommendations
• The example of in-site recommendations
  implementation
• Gain issued from the methodology implementation

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1. A brief presentation of EDF Group and UTO
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A brief presentation of the EDF Group

• The EDF Group a leading player in the European
  energy industry.
• EDF Group is present in all areas of the
  electricity value chain, from generation to
  trading, and active in the gas chain in Europe.
• Leader in the French electricity market, the
  Group also has solid positions in the United
  Kingdom, Germany and Italy.

Breakdown of EDF Group's generation worlwide
Installed capacity
RE Renewable Energies
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UTO a Nuclear Technical Support Unit

• In charge of Fleet Maintenance
• for EDF NPPs
• (Nuclear Power Plants)

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2. From PANTHER-RP simulation to practical
recommandations
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PANTHER-RP models and calculations
spectrometry data, radiological map
radiological model
Maintenance programm Workstations, task duration
Biological protection list Workstations, task
duration
Plans et iso 3D models
workstation
Source
Biological Protection
Dose rates calculation for each source and for
each workstation
Dose rate reduction coefficient calculation for
each option
PANTHER-RP Model
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An UTO recommandation example
shielding definition

BOUCLE 1

Local R412

RCP120VP

Radiological protection option

12 mm lead shield in front of hot branch

Lead matress aound RCP 120 valve
RCP120VP
12 mm lead shield
Lead matress
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-
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3. An implementation example
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TRICASTIN example

• The NPP has identified UTO recommendations in the
  logistic activities management

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TRICASTIN example

• UTO recommendations are also integrated in the
  shielding contractor documents

Lead Screen
RCP 120 VP valve
gratting
Hot Branch
Lead matress
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4. Gains
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Gains the integrated dose

• In 2006  radiological gains around 25 H.mSv
  issued from UTO recommendation implementation
  compared to implementation based on habits
• An optimised shielding implementation the
  methodology developed helps NPP in choosing the
  best ALARA radiation protection options.

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This progress, based on TRICASTIN example, is due
to
More biological protections
Contributing sources identification
Justification of the lead mattresses thickness
from 6 mm to 12 mm
Optimal scenario definition
Mechanical stress calculations
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New biological protection  
Permanent shielding support
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Conclusion

• These elements leads to encouraging collective
  integrated dose decrease compared to the
  historical and empirical approaches that were
  previously implemented on-site.
• A prototype tool, that will help NPPs to analyse
  the optimal shielding protection implementation
  scenario, will be tested in 2 years on a real
  outage in Tricastin in 2010.