Ontario Power Generation Case Study

How a nuclear power producer standardized on a Group II–based turbine oil and extended reliability—validated by rigorous lab testing.

By selecting a premium Group II–based turbine fluid, Ontario Power Generation (OPG) achieved consistent oxidation stability, excellent water separability, and reliable air release across severe steam-turbine conditions

Quick Facts

Problem

Aging Group I turbine oil and rising reliability risks in high-temperature steam-turbine service at a major nuclear facility.

Resolution

A performance-based specification led OPG to a premium Group II–based turbine oil program (Petro-Canada TURBOFLO™ XL) with industry-leading RPVOT, fast water separation, and dependable air release—meeting or exceeding OEM requirements.

About Ontario Power Generation

OPG is one of North America’s largest electricity producers, operating nuclear generating stations near Toronto along with hydro, oil, and gas-fueled plants. Its Darlington Nuclear station alone supplies a significant share of Ontario’s electricity and was selected for a multi-year refurbishment—an ideal moment to re-baseline turbine-oil specs and performance.

The Challenge

The Solution

Challenge

Move from a long-used Group I turbine oil to a modern fluid without sacrificing demulsibility, oxidation resistance, or cleanliness—under tight regulatory oversight and with detailed justification for any change.

Solution

OPG designed a multi-month evaluation of eight candidate turbine oils (Group I, Group II, and blends), aging samples under controlled conditions and weighting critical properties like RPVOT and TAN most heavily. Results guided a new, performance-based specification centered on Group II oils.

Challenge

Mitigate varnish risk and aging-oil issues (rust, deposit formation, TAN growth) while maintaining uptime on high-temperature steam turbines reaching >100 °C casings and complex auxiliary systems.

Solution

Adopted a Group II turbine oil—Petro-Canada TURBOFLO™ XL—under a performance-based spec for high oxidation stability and fast water/air release, cutting varnish and aging issues while maintaining uptime.

Challenge

Prove performance with data: OPG required staged, ASTM-based testing (artificial aging, RPVOT, oxidation/TAN, air release, demulsibility, particle counts, membrane patch colorimetry) to compare candidate oils.

Solution

TURBOFLO XL is suitable where GE (GEK 32568J/46506E), Siemens (TLV 9013 04/05), and other major specifications apply—covering both steam and stationary gas turbines, including high-temperature bearings with sealing-air temps >260 °C (500 °F).

The Results

By weighting RPVOT, TAN, air release, demulsibility, and cleanliness across both aging and post-aging stages, OPG found that well-formulated Group II oils delivered the most consistent performance—enabling OPG to author a performance-based turbine-oil spec and transition away from Group I. TURBOFLO XL’s data profile—very high RPVOT, quick water shedding, stable viscosity, and strong anti-foam/air-release—fits those requirements and reduces risk of varnish, rust, and unplanned change-outs in severe service.

The lesson learned from our point of view is that all Group II oils are not the same....In my opinion, base oil quality impacted a lot, in comparison with additive pack performance. Certainly, well-formulated oils with proper additives have made the difference in the final results.

Khalid Malik

Ontario Power Generation

TURBOFLO™ XL

Premium turbine fluid for severe service

TURBOFLO™ XL is engineered to lubricate and cool steam, hydraulic, and gas turbines while delivering reliable protection to bearings operating in harsh conditions.

Blue Def

Download the Ontario Power Generation Case Study