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Scott Cameron Manager Radiation Protection 2008 International ALARA Symposium

ALARA Performance at OPG. Scott Cameron Manager Radiation Protection 2008 International ALARA Symposium. Overview. Introduction Dose Reduction Initiatives Human Performance Improvements Future Challenges. Dose Reduction Initiatives: Darlington Installation of Submicron Filtration.

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Scott Cameron Manager Radiation Protection 2008 International ALARA Symposium

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  1. ALARA Performance at • OPG Scott Cameron Manager Radiation Protection 2008 International ALARA Symposium

  2. Overview • Introduction • Dose Reduction Initiatives • Human PerformanceImprovements • Future Challenges

  3. Dose Reduction Initiatives:DarlingtonInstallation of Submicron Filtration • HTS bleed filter pore size reduced in steps from 2 uM to 0.45 uM in May/2002 and 0.1 uM in Dec/2003 • Increased filter replacement rate was driven by dose rate not ΔP • Contribution to dose savings: 130 rem for Unit 1 since 2004

  4. Dose Reduction Initiatives:Remote Monitoring • Teledosimetry for dose monitoring and Rx face scan Remote readout of gamma and tritium levels at airlock (HP)

  5. Dose Reduction Initiatives: Shielding Applications • Water wall for on-power Airlock EQ work – 3 rem dose and 4 M$ outage critical path savings • Water bag for ECI hot spot shielding • Face shielding Rx Shield Block Data: Each block weighs 22 lbs with a 7” hole cut out 15 min and 14 mrem to install 35 blocks Shielding effectiveness: Before shielding – 90 mrem/h, after shielding – 42 mrem/h

  6. Dose Reduction Initiatives: Decontamination • Application of strippable Decon Gel • Example: • HX1 room floor Coated and peeled the next day • Before – 5000 cpm • After - 0 cpm • Peeling - 4.5 mrem/h C

  7. Internal Dose Reduction: Outage Tritium Reduction ALARA Plan • Action Levels established with pre-determined corrective actions • Reduce closure plug leakage (CP tightening, PHT low level drain state to reduce static pressure) • Install portable dryers (96% capacity factor, 24 drums of D2O, 1200 Ci extracted from vault air) • Contain and reduce tritium @ airlocks (H3 <0.1 MPCa outside AL) Munter Dryer

  8. Human Performance Improvement:Impact of Worker Practice • Human performance has a large impact on the effectiveness of RPPE: • Good RP practice can increase protection factor (PF) by a factor of 2 • Human performance can be improved by communication and focused O&C’s 1st wave of intense communication

  9. Human Performance Improvement:Example of Worker Communication Campaign Communication campaign to emphasize impact of unplugged time on tritium uptake: Video presentation and posters Outage handbook Safety meetings

  10. Human Performance Improvement:Coaching, Monitoring & Follow-up Daily dose monitoring and follow-up of EPD dose and tritium uptake Action levels: • 3 uCi/l or 10 mrem EPD – follow-up with worker/supervisor • 10 uCi/l above planned or EPD alarm – department EFDR, SCR • 35 uCi/l above planned or 100 mrem above EPD alarm – root cause investigation Performance management • Focused observation and coaching (O&C) by RP staff • Interview by RPM and RHP for significant events or repeats • RP qualification review of worker and supervisor

  11. ALARA Achievement Three Consecutive WANO Strengths in ALARA 2007, 2008 WANO: • High standards in RP have been set and achieved • Robust controls prevent unplanned exposures • Extensive ALARA planning, innovative shielding and aggressive tritium reduction • Reactor face shielding • On-line tritium / gamma system

  12. Future Challenges:2. Reduce γ dose rate in HT system by 25% by 2011 • Gamma scans identify Co-60 as the dominant source of radiation • More than 80% of Co-60 originates from FM stellite ram balls • Long term plan: COG joint/R&D project to develop replacement • Short term plan: FM filtration improvement – submicron filters & IX

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