1. OPG WTP Performance / Trends in High Purity Water Treatment Presented at IAPWS Workshop May 11, 2009 By Gabriel Nicolaides

2. Outline Darlington WTP - Background Pickering WTP - Background Demin Water Quality: DND vs. PND Demin Water Quality Survey Trends in High Purity Water Treatment New WTP Design Considerations RO for Primary Demineralization UF for Pretreatment Different Options for Polishing Deionization

3. Darlington WTP - Background  WTP design finalized in 1985, WTP in service 1986  Fourth in a series of WTPs designed by “old” Ontario Hydro: 1. PNGS, 2. BNGS-A, 3. BNGS-B, 4. DNGS  “conventional” WTP design consisting of clarification / sand filtration / activated carbon / ion exchange  Key features incorporated into the design of the WTP: Deep water intake 1 km off-shore, 10 m below the water surface Dual clarifiers External regeneration of mixed beds

4. Darlington WTP Process

5. Pickering WTP - Background OPG’s 1 st outsourced WTP 10 year operating contract awarded to Nalco in Feb. 2001; a local company, Eco- Tec, supplied the equipment and assists with WTP operation and key maintenance activities WTP in-service since Oct. 2001

6. Site Selection/Raw Water Source WTP located outside of protected area; allows vendor ready access and permits equipment retrofits as commercial modifications CCWR outfall structure used for raw water supply pumps, warm raw water for improved RO efficiency and reduced foot- print

7. Pickering WTP – External View OPG owns the building housing the WTP; Nalco owns and operates the equipment

8. PND WTP Process

9. Pickering WTP – Internal View

10. Demin Water Quality: DND vs. PND

11. Demin Water Quality Survey DND WTP was ranked against 24 other Nuclear Stations. DND WTP ranked 10th out of 25 stations, placing it in the 2nd quartile PND WTP ranked 6th out of the 25 stations, placing it in the 1st quartile

12. Trends in High Purity Water Treatment Outsourcing of WTP Operation Extensive Use of Membrane-Based Technologies (e.g. UF, RO) Improved demin water quality especially lower Na & TOC levels Reduction / elimination of hazardous chemicals (acid, caustic) Automatic operation / remote monitoring reduces labour cost

13. New WTP Design Considerations What are you starting with? - Feed water Quality & Characteristics –Source – surface water, well water, other –Seasonal Variations & Effects –Dissolved & Suspended Solids What quality do you need? - Finished water Quality & Characteristics –Benchmark Chemistry –Dissolved Solids (TDS, specific ions, etc.) –TOC

14. “Heart” of the Water Treatment System is RO ROUF EDI or IX polishing

15. RO Membrane Feed Specs RO feedwater requirements are:  SDI:< 3.0  Chlorine (free):< 0.01 ppm  Iron:< 0.1 ppm  Turbidity:< 0.2 NTU

16. Filtration Spectrum

17. Hollow-fibre Ultrafiltration Screen Reject / neutralized waste to drain

18. Comparison of UF vs. MMF PretreatmentUFConventional Description ZW 1000 IHF UF, Out/In 0.02  m nominal pore size MMF 5  m cartridge filter Treated Water Quality Consistent, reliable quality SDI < 2.5, 100% of the time, usually < 1.5 Turbidity: < 0.1 NTU Positive barrier to particles and pathogens - no breakthrough Bacteria: > 5 log removal GiardiaCyst: > 4 log removal Virus: > 4 log removal Fluctuating quality SDI < 4 ~90% of the time Turbidity: < 1.0 NTU MMF not a positive barrier to colloidal and suspended particles. Quality of water produced fluctuates significantly with respect to particulates.

19. RO Membrane Systems: < 2 MegOhm RO rejection range of 96 – 99+% on dissolved solids

20. Deionization: 2 – 18 MegOhm –Electrodeionization (EDI) – regenerated continuously with electricity –Traditional DI – resin is regenerated with acid and caustic on-site –Traditional DI – resin regenerated off-site

21. Acknowledgements GE Water & Process Technologies: Sandy Schexnailder