Wellgreen Project Preliminary Economic Assessment ... - OTCIQ.com

As of September 2011, the generating capacity of the Yukon Electrical Company
Limited (YECL) is 112 MW (75 MW from hydroelectric power generation stations,
36 MW from diesel generators and 1 MW from wind turbines). YEC is exploring the
possibility of increasing its hydroelectric generating capacity by 30 to 40 MW
between 2012 and 2020.
Drawing power from the YEC power grid will not be sufficient for the Project power
demand at present. Therefore several options for on-site power generation without a
connection to a power grid were considered for the property of the Project.
After overall evaluation (based on the criteria of the levelized cost of electricity
(LCOE)), fuel supply availablity, power supply availability and continuity of service,
constructability, ease of operation, maintainability, safety, and emission from
combustion), a CHP plant with diesel fuel generator has been selected for the
Wellgreen PEA. Fuel supply is assumed to be diesel natural gas which will be
delivered by truck to the plant. The total power demand for the Project is estimated
to be 40 MW which includes allowances of 10% for the power plant load, losses,
contingency and future loads.
A power plant consisting of 6x10 MW (site condition performance) low speed engine
generator sets (N+1), operating at 13.8 kV, 60 Hz output voltage, is considered
sufficient to meet this demand.
Recovered heat energy from the CHP plant will be used for heating the process plant
area infrastructure.
The LCOE for the Wellgreen PEA is estimated to be Cdn$0.28/kWh.
18.4 P ROPOSED T AILINGS S TORAGE
All tailings dams will be constructed of compacted rock fill using the downstream
method with a geomembrane liner on the upstream face. The tailings impoundment
footprint will be lined with a low density polyethylene liner over a layer of broadly
graded silty sand and gravel, to act as low permeability bedding material and provide
secondary containment.
Material for construction will be sourced from the site during initial construction and
from the open pit, for the later raises during operations.
Based on the tailings storage requirements, the starter dams required to store one
year of tailings plus freeboard will be 2.25 m high based on a conservative “rate of
rise” for the dam. The final wall height will be 60 m.
In Year 28, a second impoundment will be built to contain the remaining tails. The
TMF will have an ultimate capacity of approximately 280 Mm 3 , corresponding to an
Prophecy Platinum Corp. 18-3 1193460500-REP-R0001-02
Wellgreen Project Preliminary Economic Assessment,
Yukon, Canada