DRC-2013-001869 - 0901a068803639e4

ENERGYFUELS
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
www.energyfuels.com
VIA EMAIL AND OVERNIGHT DELIVERY
March 29,2013
Mr. Rusty Lundberg
Director of the Utah Division of Radiation Control
State of Utah Department of Environmental Quality
195 North 1950 West
P.O. Box 144850
Salt Lake City, UT 84116-4850
Re: White Mesa Uranium MUl - RML UT1900479
Transmittal of Safety and Environmental Review Panel C'SERP'') Annual Report
Dear Mr. Lundberg: DRC-2013-001869
Enclosed please find the 2012 Annual SERP Report for the White Mesa Mill, which is being submitted
in compliance with condition 9.4 C of State of Utah Radioactive Materials License No. UT 1900479.
If you have any questions, please contact me at [phone].
Yours very truly.
ENERGY FUELS RESOURCES (USA) INC.
Jo Ann Tischler
Manager, Compliance and Licensing
cc David C. Frydenlund
Phil Goble, Utah DRC
Dan Hillsten
Ronnie Nieves
Harold R. Roberts
David E. Turk
Kathy Weinel
Attachments
N:\WMM\Required Reports\SERP Reports\2012 SERP Reports\03.29.13 tmsmtl 2012 SERP Ann report.doc
WHITE MESA MILL
SAFETY AND ENVIRONMENTAL REVIEW PANEL (SERP)
2012 ANNUAL REPORT
March 29,2013
Submitted to the Utah Department of Enviroimiental Quality
Division of Radiation Control
Submitted by:
White Mesa Uranium Mill
License No. UT 1900479
1. INTRODUCTION
This report is being submitted by Energy Fuels Resources (USA) Inc. ("EFRI"), licensee of the
White Mesa Uranium Mill (the "Mill") to the Utah Division of Radiation Control ("DRC") in
compliance with condition 9.4 C of State of Utah Radioactive Materials License No. UT
1900479 (the "License").
There were four Safety and Environmental Review Panel ("SERP") evaluations conducted for
the period of January 1, 2012 through December 31, 2012. Each SERP evaluation and review
was conducted in accordance with SERP procedures set forth in the Mill's Standard Operating
Procedure PBL-1, Rev. No. R-4 (the "SERP SOP"). The evaluations are summarized below in
Section 2.
2. SUMMARY OF EVALUATIONS
This section describes the changes, tests, or experiments evaluated by the SERP pursuant to
License condition 9.4, and summarizes the evaluations performed and actions taken by the SERP
relative to each.
In each case, the SERP consisted of those individuals specified in License condition 9.4 C, with
additional members included as appropriate, to address technical aspects.
The SERP followed the SERP SOP as it performed its evaluations, to ensure that the actions
taken satisfy the following 3 conditions specified in License condition 9.4 B:
a) The change, test or experiment does not conflict with any requirement specifically stated
in the License, or impair the licensee's ability to meet all applicable regulations.
b) There is no degradation in the essential safety or environmental commitments in the
License application or provided by the approved reclamation plan.
c) The change, test or experiment is consistent with the conclusions of actions analyzed and
selected in the Environmental Assessment dated February 1997 (the "1997
Environmental Assessment).
2.1. SERP Report No. 2012-01 January 25, 2012 Revisions to Standard Operating
Procedure for Uranium SX Circuit
2.1.1. Proposed Action
Review and approve modifications to the Uranium Solvent Extraction ("SX") circuit
configuration and revisions to the Standard Operating Procedure for the Uranium SX
circuit (the "Uranium SX SOP"), SOP Book 4 Sections 2 and 3.
2.1.2. Description of Change, Tests or Experiments
A change to the uranium solvent extraction ("SX") circuit (the "Change") was proposed that
would reduce impurities in the loaded strip solution and the yellowcake product by converting
one of the four strippers into an impurity removal stage and adding a crud breaking step.
Because the Change involved only re-arrangement of piping, there was some question as to
whether a SERP was required. A SERP meeting was conducted for purposes of thoroughness.
2.1.3. Safety and Environmental Evaluation of this SERP Action
The SERP reviewed the proposed revision and determined that:
• Since the Change was limited to re-arrangement of piping, it involved no new feeds,
reagents or other materials, or changes to rates of addition.
• The Change does not generate any new radiation or occupational safety issues.
• The Change has no impact on environmental emissions or on the tailings system.
The SERP concluded that:
a) The Change, does not conflict with any requirements, such as yellowcake production,
specifically stated in the license. Because it has no effect on Mill feeds or emissions,
it does not affect Mill operations in any aspect addressed by any of the Mill's permits
or any regulations.
b) The Change will not produce any degradation in the essential safety or environmental
commitments in the License application, its scope is within the envelope of
environmental conditions assumed in the EA, and it has no effect on reclamation
commitments. The Change will not modify types or rates of feed, will not produce
any new environmental emissions, and has no effect on tailings.
c) The Change does not involve any new feeds, wastes, process material or operating
conditions, and would therefore produce no environmental impact beyond those
assessed in the EA dated February 1997.
2.1.4. SERP Action
The SERP concluded that the Change and the revised Uranium SX SOP meet the criteria set
forth in the SERP SOP for approval, and approved the Change and the revision.
2.2. SERP Report No. 2012-02 February 9, 2012 Review and Approval of Standard
Operating Procedure for Calcined Material Processing
2.2.1. Proposed Action
Review and approve revisions (the "Calcined Change") to the Calcined alternate feed
material ("Calcined Material") Standard Operating Procedure (the "SOP" or "Calcined
Material SOP") for processing of Calcined Material from Cameco Corporation's Blind
River Facility. PBL-13, Nodes 1 through 3 (the "Procedure").
2.2.2. Descriptions of Change. Tests or Experiments
The Mill has an existing License amendment to process alternate feed material from Cameco
Corporation's Blind River Facility, and has previously processed this material in the Mill's main
circuit. The Mill planned to resume processing Calcined Material in the main circuit via a
modified procedure which uses fewer chemical reagents and which can be run in continuous or
batch mode. The Calcined Change is reflected in revisions to the Procedure
2.2.3 Safetv and Environmental Evaluation of this SERP Action
The SERP reviewed the Procedure described above and concluded that:
a) The Calcined Change will eliminate the use of two reagents (ammonia and caustic) for
this feed, and will reduce the concentration of sulfuric acid required for this feed.
b) The process will use the same solvent extraction and drying and packaging nodes as
used for ores and previously used for this alternate feed.
c) As a result, no new Personnel Protective Equipment ("PPE") would be required, no
changes to derived air concentration ("DACs") would be required, and no new radiation
or safety issues would be produced by the Calcined Change.
d) There would be no increase in environmental emissions and no change in nature or
volume of tailings due to the Calcined Change.
2.2.4 SERP Action
The SERP concluded that:
a) The Procedure, as amended by the Calcined Change, does not conflict with any
requirements specifically stated in the license, or impair EFRI's ability to meet all
applicable regulations. The material is akeady covered by an existing license
amendment. The Mill has remained in compliance with the License and other regulatory
requirements while running this and other feeds requiring more processing stages and
reagents than the revised Procedure.
b) The Calcined Change will not produce any degradation in the essential safety or
environmental commitments in the License application, or provided by the approved
reclamation plan. The Calcined Change involves a feed already processed previously at
the Mill, and involves no new reagents, chemical or radiological hazards or
environmental emissions. It would have no effect on the volume or nature of tailings.
c) The Calcined Change is not expected to produce any environmental impacts beyond
those assessed in the EA dated February 1997, and is consistent with the conclusions
regarding actions analyzed in the EA. The Calcined Change would use fewer and/or
lower concentration of reagents than assumed in the EA, and produce no new
environmental emissions. The volumes of solutions and solid tailings that would be
transferred to the tailings cells will remain the same. There would be no new pathways
of exposure to workers or the public.
The SERP concluded that the Procedure meets the criteria set forth in the SERP SOP for
approval, and approved the Calcined Change and revised Procedure.
2.3 SERP Report No. 2012-03 February 24, 2012 Modifications to the Calcined
Alternate Feed Drum Unloading/Feed Addition Area
2.3.1 Proposed Action
Review and approve modifications to the Calcined alternate feed material ("Calcined
Material") drum unloading area/feed addition area for feeding of Calcined material from
Cameco Corporation's Blind River Facility (the "Drum Unloading Change").
2.3.2 Descriptions of Change. Tests or Experiments
The Mill has an existing License amendment to process alternate feed material from Cameco
Corporation's Blind River Facility, including drummed calcined alternate feed. The Drum
Unloading Change involves construction of an extension to the concrete pad at the current drum
emptying and washing station, where calcined feed, and other, drums are unloaded. The
proposed extension would receive emptied, washed drums after unloading of feed material imtil
they are picked up by a transfer truck for transfer to tailings, and would be large enough to allow
a truck to back up to the emptying station.
2.3.3 Safetv and Environmental Evaluation of this SERP Action
The SERP evaluated information and correspondence related to the proposed Drum Unloading
Change and determined that the change is limited to an extension of an existing concrete pad and
involves no process, feed, or material change whatsoever.
Therefore there are no anticipated new environmental emissions or emission sources, no
additional impacts on existing worker safety and no effects on the process or the tailings system.
The Drum Unloading Change will allow the transfer truck to pull closer to the emptying station,
and will provide a means to prevent any contact between residual wash water in the drums with
the ground surface.
2.3.4 SERP Action
The SERP concluded that:
a) The Drum Unloading Change does not conflict with any requirements specifically
stated in the license, or impair EFRI's ability to meet all applicable regulations. It
will improve EFRI's ability to comply with Part I.D.I l.d of the Mill's Groundwater
Discharge Permit.
b) The Drum Unloading Change will not produce any degradation in the essential safety
or environmental commitments in the License application, or provided by the
approved reclamation plan, and therefore this criterion is met. The reclamation surety
estimate already addresses removal and disposal of surface concrete and the
additional volume of concrete resulting from the Drum Unloading Change is too
small to affect the estimate.
c) The Drum Unloading Change has no effect on any assumption or condition assumed
in the EA dated February 1997. Therefore, the Drum Unloading Change is not
expected to produce any environmental impacts beyond those assessed in the EA, and
is consistent with the conclusions regarding actions analyzed in the EA.
The SERP concluded that the proposed modification meets the criteria set forth in the SERP SOP
for approval, and approved the Drum Unloading Change. The SERP authorized immediate
implementation of the Change
2.4 SERP Report No. 2012-04 June 21, 2012 Review and Approval of Standard
Operating Procedure for KF Alternate Feed Material Processing
2.4.1 Proposed Action
Review and approve revisions (the "KF Change") to the KF alternate feed material ("KF
Material" or "KF") Standard Operating Procedure (the "SOP" or "KF SOP") for
processing of KF Material from Cameco Corporation's Port Hope Facility.
2.4.2 Descriptions of Change. Tests or Experiments
The Mill has an existing License amendment to process the alternate feed material known as the
fluoride product, potassium fluoride, or KF, from Cameco Corporation's Port Hope Facility.
The existing (previous) SOP was based on processing the KF in the main Mill circuit via an acid
leach, countercurrent decantation ("CCD"), and solvent extraction process utilizing ammonia
precipitation. The proposed KF Change would modify the process into a multi-step water and
carbonate leach process.
2.4.3 Safetv and Environmental Evaluation of this SERP Action
The SERP evaluated the proposed KF Change and determined that:
Based on a radiological characterization of a composite from a number of drums, the KF material
is comparable to previous KF material received and processed at the Mill.
The proposed KF Change to the SOP will provide improved management of fluoride ion from
the KF. The KF Change will remove the fluoride ion in a water environment, leach the uranium
in a carbonate environment, and eliminate any opportunity for fluoride exposure to sulfuric acid.
The processing will not require the use of any additional chemicals beyond those already in
storage and use at the Mill, and due to the elimination of sulfuric acid from the processing will
use fewer chemicals and fewer process steps. Therefore, there will be no new emissions or
emissions sources, no new sources of exposure to workers or the public, and no changes in DAcs
or PPE required.
2.4.4 SERP Action
The SERP concluded that:
a. The KF Change does not conflict with any requirements specifically stated in the
License, or impair EFRI's ability to meet all applicable regulations. Processing of the
feed is already covered by an existing license condition. The Mill has remained in
compliance with the License and other regulatory requirements while running a
comparable process as will be required under the KF Change. The yellowcake
recovered from the KF material will not cause the Mill to exceed the yellowcake
production limit under the License.
b. The KF Change (increase in volume) will not produce any degradation in the
essential safety or environmental commitments in the License application, or
provided by the approved reclamation plan, and therefore this criterion is met. The
KF Change will not affect the volume of tailings, which would be the same whether
the former or proposed process is used.
c. The KF Change is not expected to produce any environmental impacts beyond those
assessed in the EA dated February 1997, and is consistent with the conclusions
regarding actions analyzed in the EA. All reagents proposed in the change are within
the envelope of materials considered in the EA.
The SERP concluded that the KF Change meets the criteria set forth in the SERP SOP for
approval, and approved the KF Change. The SERP authorized immediate implementation of the
KF Change.
ATTACHMENT 1
Revisions to Uranium SX SOP
While Mesa Mill - Standard Operating Procedures Dale: 01/12 Revision: DUSA 4
Book 4 Section 2 Page I of 4
URANIUM SOLVENT EXTRACTION
The purpose of the uranium solvent extraction circuit is to extract the uranium
from the uranium bearing acid solution produced while leaching ore.
The uranium SX circuit consists of four extractor mixer-settlers: one acid wash
mixer-settler, four strip mixer-settlers, one barren organic tank, one soda ash day tank,
two brine make-up tank, one organic regeneration mixer-settler, one loaded strip tank,
and all associated pumps and piping.
Organic is used in the settlers to extract the uranium from the uranium bearing
acid solution from leach. The organic is a mixture of amine, isodeconal, and kerosene.
Each of the four extractors is designed with an overflow weir, an underflow weir,
a mix tank, and is operated in a counter-current operation. Each extractor has an organic
recycle line with a manually operated control valve. The valves are generally run in a full
open position with the purpose of getting as much organic as possible to contact the
uranium bearing solution. The mixer pulls the organic from the overflow weir of its own
extractor, through the recycle line, and back into the mixer.
Barren organic is pumped from the barren organic tank to the number four
extractor mixer and flows in a reverse order of four, three, two, and one. While the
uranium bearing solution from leach is pumped to the number one extractor and moves in
a forward order of one, two, three, and four. The mixer of each extractor works as a
pump, pulling the organic from one extractor and pulling the uranium bearing solution
from the opposite extractor.
Example: The mixer of the number two extractor pulls organic from the overflow
of the number three extractor and, at the same time, pulls uranium solution from the
underflow of the number one extractor and also pulls extra organic back through the
recycle line.
The mixing process allows the organic to contact the uranium solution, thus
extracting the uranium from the uranium bearing solution and loading it onto the organic.
E.\Mill SOP Master CopyVBook 04_Uranium SXVDUSA Book no4\DU$A renumbered seciions\Sect>on 2 Uranium Solvent
Extraction Rev.fourOil72012.doc\]/17/20l2\Rev. 2
While Mesa Mill - Standard Operating Procedures Date: 01/12 Revision: DUS A 4
Book 4 Section 2 Page 2 of 4
The uranium bearing acid leach solution pumped from the leach process is
pumped to the mixer of the number one extractor and mixed with the organic. The mixed
material overflows into the main body of the extractor where the organic and the acid
solution are allowed to separate. The organic rises to the top and overflows the overflow
weir to the acid wash settler and the acid solution stays on the bottom and flows through
the underflow weir to the opposite extractor. After the acid solution has flowed through
the four extractors, it will be virtually free of all uranium and becomes barren solution.
The barren solution is then pumped to tailings unless the vanadium circuit is running.
Barren solution that went through the uranium SX that contains vanadium is
pumped to the vanadium solvent extraction circuit to extract the vanadium from the acid
solution.
Organic which has traveled through all four extractors is now loaded with
uranium. The organic is then pulled to the acid wash where it is mixed with water. The
water is maintained at a specified pH and contacted with the loaded organic and washes
out impurities that are considered waste, such as arsenic and iron. The loaded organic
then moves into the stripping circuit.
Brine (salt) solution is used to strip the uranium from the organic as well as act as
an impurity removal. The brine solution (also called "barren strip") is pumped to the
organic advance in the acid wash overflow weir and continues with the organic to the
number one stripper. This removes impuries such as zirconium, vanadium and arsenic
from the loaded organic along with some uranium. The aqueous solution from the
number one stripper is recycled back to the organic advance of the number two extractor
to recover any uranium contained in the liquor. The loaded organic then moves to the
number two stripper to recover the loaded uranium.
The brine solution is also introduced to the mixer of the number four stripper and
flows in a reverse order of four, three and then to two. When the brine solution reaches
the underflow of the number two stripper, it is loaded with the uranium. The loaded strip
solution is then pumped into the loaded strip holding tank where it is later pumped to the
uranium precipitation circuit.
E:\Mill SOP Master CopyXBook 04_Uranium SXVDUSA Book no4\DUSA renumbered sections\Section 2 Uranium Solvent
Extraction Rev.four 011720I2.doc\l/17/20l2\Rev. 2
White Mesa Mill - Standard Operating Procedures Date: 01/12 Revision: DUSA 4
Book 4 Section 2 Page 3 of 4
Each stripper also has a recycle line but, unlike the extractors which recycle the
organic, the strippers recycle the brine solution (or the underflow) with the same purpose
of more contact with the organic for maximum stripping of the organic. Each recycle line
has a manually operated valve for control of the strip loading.
The stripped organic coming off of the overflow of the number four stripper can
then be sent to the barren organic holding tank, or can be sent into the regeneration
vessel.
Periodically, the organic becomes contaminated with minerals and/or properties
which inhibit the extraction process. To clean the organic, we regenerate it by using a
high pH soda ash solution with a small amount of caustic soda. The spent regeneration
solution can be sent to tails or, if the spent solution has a sizable amount of uranium, it
can be pumped back into the extraction circuit. The clean (barren) organic is then
pumped into the barren organic holding tank. The organic can then be pumped back to
the number four extractor and the process can start again. ^
The caustic soda used in this process is stored in a bulk holding tank outside the
north end of the SX building.
The soda ash is stored in a dry holding bin on the north side of the SX. The dry
soda ash is augured into a wet tank where a specified gravity is obtained. The liquid soda
ash is then pumped inside the building to the soda ash day tank to be used when needed in
the regeneration tank.
The salt is also stored in a holding tank on the north end of the SX building.
Water is added to this tank to make a saturated solution of brine. The saturated brine is
pumped to the barren strip make up tank where it is diluted to a specified gravity with the
overflow solution from the number one yellowcake thickener. Sulfuric acid is added to
the diluted brine solution until a pH of 1.4 is obtained.
Spills in the SX building flow to a sump at the west end of the building and are
pumped back to the circuit.
The controls, start/stop switches, indicators, readouts, and alarms which are
located in the central control room in the main mill building.The power supply, main
E:\Mil] SOP Master CopyXBook 04_Uranium SXVDUSA Book no4\DUSA renumbered sectionsNSeclion 2 Uranium Solvent
Extraction Rev.fourOI l720l2.doc\l/l7/20l2\Rev. 2
White Mesa Mill - Standard Operating Procedures Date: 01/12 Revision: DUSA 4
Book 4 Section 2 Page 4 of 4
electrical disconnects, overhead light switches, and overhead fan switches for all
associated equipment are located in the MCC room on the north side of the SX building.
Safetv Procedures
Because of the flash point of the kerosene used in the SX building, the following
rules normally apply:
1. No gasoline driven engines are allowed in the building at any time.
2. No matches, lighters, or any spark producing items are allowed in the building.
3. No cutting, welding, or grinding is allowed in the building.
4. All electric motors used in the SX have to be explosion proof.
5. Should maintenance activities require the use of cutting, welding or grinding devices,
the atmosphere must be monitored for the appropriate hazard and work must proceed
after a safety analysis has been performed.
J
E.\Mill SOP Master Copy\Book 04_Uranium SXNOUSA Book no4\DUSA renumbered sec!ions\Section 2 Uranium Solvent
Extraction Rev.fourOI l72012.doc\I/17/20l2\Rev. 2
White Mesa Mill > Standard Operating Procedures Date: 11A)8 Revision: DUSA 1
Book 4 Section 2 Page 1 of 5
URANIUM SOLVENT EXTRACTION
The purpose of the uranium solvent extraction circuit is to extract the uranium
from the uranium bearing acid solution produced while leaching ore.
The uranium SX circuit consists of four extractor mixer-settlers: one acid wash
mixer-settler, four strip mixer-settlers, one barren organic tank, one soda ash day tank,
two brine make-up tank, one organic regeneration mixer-settler, one loaded strip tank,
and all associated pumps and piping.
Organic is used in the settlers to extract the uranium from the uranium bearing
acid solution from leach. The organic is a mixture of amine, isodeconal, and kerosene.
Each of the four extractors is designed with an overflow weir, an underflow weir,
a mix tank, and is operated in a counter-current operation. Each extractor has an organic
recycle line with a manually operated control valve. The valves are generally run in a full
open position with the purpose of getting as much organic as possible to contact the
uranium bearing solution. The mixer pulls the organic from the overflow weir of its own
extractor, through the recycle line, and back into the mixer.
Barren organic is pumped from the barren organic tank to the number four
extractor mixer and flows in a reverse order of four, three, two, and one. While the
uranium bearing solution from leach is pumped to the number one extractor and moves in
a forward order of one, two, three, and four. The mixer of each extractor works as a
pump, pulling the organic from one extractor and pulling the uranium bearing solution
from the opposite extractor.
Example: The mixer of the number two extractor pulls organic from the overflow
of the number three extractor and, at the same time, pulls uranium solution from the
underflow of the number one extractor and also pulls extra organic back through the
recycle line.
The mixing process allows the organic to contact the uranium solution, thus
extracting the uranium from the uranium bearing solution and loading it onto the organic.
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White Mesa Mill - Standard Operating Procedures Date: 11/08 Revision: DUSA I
Book 4 Section 2 Page 2 of 5
The uranium bearing acid leach solution pumped from the leach process is
pumped to the mixer of the number one extractor and mixed with the organic. The mixed
material overflows into the main body of the extractor where the organic and the acid
solution are allowed to separate. The organic rises to the top and overflows the overflow
weir to the acid wash settler and the acid solution stays on the bottom and flows through
the underflow weir to the opposite extractor. After the acid solution has flowed through
the four extractors, it will be virtually free of all uranium and becomes barren solution.
The barren solution is then pumped to tailings unless the vanadium circuit is running.
Barren solution that went through the uranium SX that contains vanadium is
pumped to the vanadium solvent extraction circuit to extract the vanadium from the acid
solution.
Organic which has traveled through all four extractors is now loaded with
uranium. The organic is then pulled to the acid wash where it is mixed with water. The
water is maintained at a specified pH and contacted with the loaded organic and washes
out impurities that are considered waste, such as arsenic and iron. The loaded organic
then moves into the stripping circuit.
Brine (salt) solution is used to strip the uranium from the organic as well as act as
an impurity removal. The brine solution (also called "barren strip") is pumped to the
organic advance in the acid wash overflow weir and continues with the organic to the
number one stripper. This removes impuries such as zirconium, vanadium and arsenic
from the loaded organic along with some uranium. The aqueous solution from the
number one stripper is recycled back to the organic advance of the number two extractor
to recover any uranium contained in the liquor. The loaded organic then moves to the
number two stripper to recover the loaded uranium.
The brine solution is also introduced to the mixer of the number four stripper and
flows in a reverse order of four, three and then tor two, and one. When the brine solution
reaches the underflow of the number ene-two stripper, it is loaded with the uranium. The
loaded strip solution is then pumped into the loaded strip holding tank where it is later
pumped to the uranium precipitation circuit.
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White Mesa Mill - Standard Operating Procedures Date: 11/08 Revision: DUSA 1
Book 4 Section 2 Page 3 of 5
Each stripper also has a recycle line but, unlike the extractors which recycle the
organic, the strippers recycle the brine solution (or the underflow) with the same purpose
of more contact with the organic for maximum stripping of the organic. Each recycle line
has a manually operated valve for control of the strip loading.
The stripped organic coming off of the overflow of the number four stripper can
then be sent to the barren organic holding tank, or can be sent into the regeneration
vessel.
Periodically, the organic becomes contaminated with minerals and/or properties
which inhibit the extraction process. To clean the organic, we regenerate it by using a
high pH soda ash solution with a small amount of caustic soda. The spent regeneration
solution can be sent to tails or, if the spent solution has a sizable amount of uranium, it
can be pumped back into the extraction circuit. The clean (barren) organic is then
pumped into the barren organic holding tank. The organic can then be pumped back to
the number four extractor and the process can start again.
The caustic soda used in this process is stored in a bulk holding tank outside the
north end of the SX building.
The soda ash is stored in a dry holding bin on the north side of the SX. The dry
soda ash is augured into a wet tank where a specified gravity is obtained. The liquid soda
ash is then pumped inside the building to the soda ash day tank to be used when needed in
the regeneration tank.
The salt is also stored in a holding tank on the north end of the SX building.
Water is added to this tank to make a saturated solution of brine. The saturated brine is
pumped to the barren strip make up tank where it is diluted to a specified gravity with the
overflow solution from the number one yellowcake thickener. Sulfuric acid is added to
the diluted brine solution until a pH of 1.4 is obtained.
Spills in the SX building flow to a sump at the west end of the building and are
pumped back to the circuit.
The controls, start/stop switches, indicators, readouts, and alarms which are
located in the central control room in the main mill building.The power supply, main
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Book 4 Section 2 Page 4 of 5
electrical disconnects, overhead light switches, and overhead fan switches for all
associated equipment are located in the MCC room on the north side of the SX building.
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White Mesa Mill - Standard Operating Procedures Dale: 11/08 Revision: DUSA 1
Book 4 Section 2 Page 5 of 5
Safety Procedures
Because of the flash point of the kerosene used in the SX building, the following
rules normally apply:
1. No gasoline driven engines are allowed in the building at any time.
2. No matches, lighters, or any spark producing items are allowed in the building.
3. No cutting, welding, or grinding is allowed in the building.
4. All electric motors used in the SX have to be explosion proof.
5. Should maintenance activities require the use of cutting, welding or grinding devices,
the atmosphere must be monitored for the appropriate hazard and work must proceed
after a safety analysis has been performed.
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White Mesa Mill - Standard Operating Procedures Dale: 01/12 Revision: DUSA 2
Book 4 Section 3 Page 1 of 2
Uranium Solvent Extraction Start Up Procedures
When both of the uranium and vanadium solvent extraction circuits are operating,
both circuits will have to be started up simultaneously to avoid overflowing extractors,
strippers, solution tanks, etc.
1. Notify your supervisor you are ready to start the circuit.
2. Notify the Vanadium SX Operator you are ready to start the feed.
a. Do not start the uranium SX until the Vanadium SX Operator has notified you
he/she is ready to start up.
3. Open the manual and automatic valves and set the flow on the panel.
4. Start the uranium raffinate pump.
5. Open the automatic lean organic valve, set the flow rate, and start the pump.
6. Start numbers one through four extractor mix tank agitators.
7. Start the acid wash mixer agitator and bleed pump.
8. Start the numbers one through four strip mixer agitators.
9. If the organic regeneration circuit is to be operated, start the organic return pump at
the regeneration settler.
10. Start the barren organic feed pump to the number four extractor mixer.
11. Start the barren strip pump to the number four strip mixer.
E:\Miil SOP Master Copy\Book 04_Uranium SXVDUSA Book no4VDUSA renumbered seclionsVSeclion 3 Stan Up Procedures
Rev.twoOl l720l2.docVl/17/20l2VRev. 0
White Mesa Mill - Standard Operating Procedures Date: 01/12 Revision: DUSA 2
Book 4 Section 3 Page 2 of 2
12. Start the barren strip and water to the number one stripper.
13. Start the number one stripper aqueous advance to the number two extractor.
14. Start the acid and add water to the acid wash.
15. Start the feed solution from the claricone at the leach.
If the organic regeneration circuit is operated, start the soda ash pump to the regeneration
settler mixer.
E:VMill SOP Master CopyVBook 04_Uranium SXVDUSA Book no4\DUSA renumbered sectionsVSection 3 Sian Up Procedures
Rev.two 01172012 dOCVI/l7/20l2VRcv. 0
While Mesa Mill - Standard Operating Procedures Dale: 11/08 Revision: DUSA I
Book 4 Section 3 Page 1 of 2
Uranium Solvent Extraction Start UP Procedures
When both of the uranium and vanadium solvent extraction circuits are operating,
both circuits will have to be staited up simultaneously to avoid overflowing extractor,
strippers, soludon tanks, etc.
1. Noti fy your supervisor you are ready to start the circuit.
2. Notify the Vanadium SX Operator you are ready to start the feed.
a. Do not start the uranium SX until the Vanadlium SX Operator has notified you
he/she is ready to start up.
3. Open the manual and automatic valves and set the flow on the panel.
4. Stan the uranium raffinate pump.
5. Open tbe automatic lean organic valve, set the flow rate, and start the pump.
6. Start numbers one through four extractor mix tank agitators.
7. Start the acid wash mixer agitator and bleed pump.
8. Start tbe numbers one through four strip mixer agitators.
9. If the organic regeneration circuit is to be operated, start the organic return pump at
the regeneration settler.
10. Start the barren organic feed pump to the number four extractor mixer.
11. Stan the barren strip pump to the number four strip mixer. FummttBd: List Pangriph, Line spadnQ:
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While Mesa Mill - Standard Operating Procedures
Book4 Section?
Dale: 11/08 Revision: DUSA 1
Page 2 of2
44T[ 2. Start the barren strip and water to the number one stripper.
447! 3. Start the number one stripper aqueous advance to the number two extractor.
ForiMttiBd: List Psrsgraph, Lme spsdng:
single, No iMllets or numbering
4^i4,Start the acid and add water to the acid wash. *' ' ~ •{ Rwimrttedj BuUetsand Numbering )
44r15.Start the feed solution from the claricone at the leach. ~ "j Pull—Itetii BuPets and Numbering ]
If the organic regeneration circuit is operated, stan the soda ash pump to the regeneration
settler mixer.
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ATTACHMENT 2
Revisions to Calcined Material SOP
10
No.: PBL-17
Rev. No.: 1.1
Date: February 2,
2012
DENISON MINING (USA) CORP.
STANDARD OPERATING PROCEDURES
Title: Calcine Drum Dumping Node
Page 1 of3
Hazard Assessment Worksheet
Equipment Component
Individual Equipment No.
Calcine Drum Dumping Node
Nodel
Parameter Process Material in Component
PFD Calcine Calcine Calcine
Quantity in Equipment (lb) 400/drum 4000/dump
tank
160,000/pulp
storage tank
Concentration (%) 100 40 20
Flashpoint, °F — —
TLV-TWA mg/m' 2.5 2.5 2.5
STEL mg/m^ NL NL NL
Radioactivity, pCi/g 5,000 5000 5000
Temperature, °C Amb Amb AMB
Pressure, psig 0-100 0-100 0-100
Health Rating 2 2 2
Hazard Rating 3 4 5
Assessment Description: This material is high in uranium and produces a very fine
powder. Dusting and contamination should be avoided. NOTE: Whenever working in,
around or on this process circuit YOU MUST wear PPE which includes at minimum
Tyvex coveralls, rubber boots and gloves, safety glasses, face shield and may include full
face respirators as instructed by the RSO or your supervisor.
REMEMBER Calcine material is radioactive and you must follow established
health physics controls as directed by the RSO. Keep the material wet at all times
and if any solution gets on you wash it off with plenty of water. Ifyou have any
questions about what you must wear or do when dumping drums ask your
supervisor or the RSO.
No.: PBL-17 DENISON MINING (USA) CORP.
Rev. No.: 1.1 STANDARD OPERATING PROCEDURES Page 2 of 3
Date: February 2, Title: Calcine Drum Dumping Node
Page 2 of 3
2012
Water
Calcine Drums
Drum dumping
station To Pulp
Tank
Operating Instructions
The various types of material in the drums must be closely momtored to make certain that
only Calcine material is dumped into the circuit. This is important because this material
may react with designed recovery process chemicals if it is different than Calcine
material and may react violently.
• Supervisor will inform you if there is any reason to suspend operations at the start
of shift or during shift.
• Make a safety inspection of all lines and equipment.
o Inspect lines for leaks or seeps.
o Inspect safety showers and eyewash foimtains.
o Report any damage or maintenance problem to supervisor and/or other
appropriate departments.
• Tum on the drum dumper and weigh scale.
• Confirmation of material will be performed during drum transport to dumping
area.
• Unfasten the lid carefully and report any unusual pressure release.
• Visually confirm material is Calcine by-product.
• Weigh and record the drum weight.
No.: PBL-17 DENISON ME^G (USA) CORP.
Rev. No.: 1.1 STANDARD OPERATING PROCEDURES Page 3 of 3
Date: February 2, Title: Calcine Drum Dumping Node
Page 3 of 3
2012
Take a sample from the drum and place it in the sample container for the daily
drum composite.
Any drummed material that may present a problem in dumping (for example,
solidified material) set aside. Supervisor will inform operator what will be done
with these dnmis.
Add the appropriate amount of water as instructed by the supervisor.
Place the drum securely in the drum dumper. Make sure the dumper water sprays
are operating before and during the dumping of any drum of Calcine material.
Take any other necessary measures for dust control during drum dumping as
instructed by your supervisor. Actuate the dumper as instructed by your
supervisor, thus emptying the drum into the dumper tank.
Upon accumulating enough of the dumped Calcine material in the dumper tank,
transfer the material to the pulp storage tanks as instructed by the supervisor.
Insure that the tank level in the pulp storage tank is above the agitator before
starting the agitator.
Agitate the slurry of Calcine material and water as instructed by the supervisor.
Continue dumping drums and transferring the slurry of Calcine material to the
pulp storage tanks until the target level in the tanks or the daily target of drums to
be dumped is reached as instructed by the supervisor.
Shut down the dumper station and clean out the equipment pertaining to the
dumper station as instructed by the supervisor.
No.: PBL-17
Rev. No.: 1.1
Date: February 2,
2012
DENISON MINING (USA) CORP.
STANDARD OPERATING PROCEDURES
Title: Calcine Acid Leach Node
Page 1 of3
Hazard Assessment Worksheet
Equipment Component
Individual Equipment No.
Calcine Acid Leach Node
Node 2
Parameter per Tank Process Material in Component
PFD H2SO4 U3O8
Quantity in Equipment (lb) 61,300 5,200
Concentration (%) 8 0.6
Flashpoint, °F —
TLV-TWA mg/m' 1.0
STEL mg/m^ 3.0
Radioactivity, pCi/g 0
Temperature, *^C 80 80
Pressure, psig 0-100
Health Rating 3
Health Hazard 7
Assessment Description: Addition of acid to a target of 60-80 gpl free acid and addition of live
steam to a target of 80°C to the first leach tank. Operators should protect themselves from
possible splashing of the leach tank contents, due to temperature, acidity, and radioactivity.
Whenever working in, around or on this process circuit the operator must wear PPE, which may
include Tyvex or Mill coveralls, rubber boots or regular steel toed boots, protective gloves, and
safety glasses. A face shield or a full face respirator maybe be required as instructed by the RSO
or your supervisor.
No.: PBL-17 DENISON MINING (USA) CORP.
Rev. No.: 1.1 STANDARD OPERATING PROCEDURES Page 2 of3
Date: February 2, Title: Calcine Acid Leach Node
Page 2 of3
2012
Slurry From Dumping Station
Calcine Leach
^ rSolid / Liquid Separation
Pulp StorageTank
Operating Instructions
This node deals with the leaching of the Calcine material.
• At the beginning of your shift, make a safety inspection of all tanks, lines and
equipment in the leach area.
o Inspect lines and tanks for leaks or seeps.
o Inspect safety showers and eyewash fountains.
o Report any damage or maintenance problem to your supervisor and/or
other appropriate departments.
• The leaching of the Calcine material will be conducted in either the
continuous or batchwise mode of operation.
• If your supervisor instructs you to operate the leach circuit in the continuous
mode, then add Calcine slurry from the pulp storage tank continuously to the
designated leach tank at a rate of 40 gallons per minute (equivalent to about
55 tons per day) or as instructed by your supervisor. Add steam to the
designated leach tanks sufficient to maintain a temperature of 80°C or as
instructed by your supervisor. Add sulfuric acid to the designated leach tanks
sufficient to maintain a free acid concentration of 60 grams per liter or as
instructed by your supervisor. Continue to maintain agitation in the
No.: PBL-17 DENISON MINING (USA) CORP.
Rev. No.: 1.1 STANDARD OPERATING PROCEDURES Page 3 of 3
Date: February 2, Title: Calcine Acid Leach Node
Page 3 of 3
2012
designated leach tanks and flow between leach tanks as instructed by your
supervisor. Transfer the leach discharge slurry to the Counter-Current
Decantation (CCD) circuit for the solid/liquid separation step of the
processing.
• If your supervisor instructs you to operate the leach circuit in the batchwise
mode, then add Calcine slurry from the pulp storage tank to the designated
leach tank at a rate as instructed by your supervisor up to a tank volume as
instructed by your supervisor. Tum on and continue agitation in the
designated leach tank as instmcted by your supervisor. Add sulfuric acid to
the designated leach tank to bring the tank contents to a free acid
concentration of 60 grams per liter or as instmcted by your supervisor. Add
steam to the designated leach tank sufficient to bring the contents to a
temperature of 80°C or as instmcted by your supervisor. Continue to add
steam as needed to maintain the temperature as instmcted by your supervisor.
Maintain leach conditions in the designated tank as instmcted by your
supervisor until the leaching step of processing is completed. Then tum off
agitation and stop reagent and steam addition in preparation for solid/liquid
separation.
• Take samples from leach tanks according to normal operation of the leach
circuit adjusted for the designated leach tanks in use and as instmcted by your
supervisor.
Always read and follow all instructions listed on the MSDS.
No.: PBL-17 DENISON MINING (USA) CORP.
Rev. No.: 1 STANDARD OPERATING PROCEDURES Page 1 of3
Date: January27, Title: Calcine Solid/Liquid Separation Node
Page 1 of3
2012
Hazard Assessment Worksheet
Equipment Component Calcine Solid/Liquid Separation Node
Individual Equipment No. Node 3
Parameter per Tank Process Material in Component
PFD H2SO4 U3O8 Flocculant
Quantity in Equipment (lb) 697,971 50,000 250
Concentration (%) 20 0.1
Flashpoint, °F ~ ~ ~
TLV-TWA mg/m' 2.5 2.5 NL
STEL mg/m^ NL NL NL
Radioactivity, pCi/g 0
Temperature, °C (F) 20 (70) 20 (70) 20 (70)
Pressure, psig 1-100 0-100 0-100
Health Rating 3 3 1
Health Hazard 7 7 1
Assessment Description: Operators should protect themselves from possible splashing of the tank
contents, due to temperature, acidity, and radioactivity. Operators should also be cautious of any
splashed or spilled flocculant solution or dry flocculant because the surfaces upon which the
flocculant lands will become dangerously slippery. Any splashed or spilled flocculant should be
cleaned up promptly by flushing the surface with generous amounts of water until the slippery
conditions are gone, or as instmcted by your supervisor. Whenever working in, around or on this
process circuit the operator must wear PPE, which may include Tyvex or Mill coveralls, mbber
boots or regular steel toed boots, protective gloves, and safety glasses. A face shield or a full face
respirator maybe be required as instmcted by the RSO or your supervisor.
No.: PBL-17 DENISON MINING (USA) CORP.
Rev. No.: 1 STANDARD OPERATING PROCEDURES Page 2 of3
Date: January27, Title: Calcine Solid/Liquid Separation Node
Page 2 of3
2012
t Leach
Circuit
Tanks
Flocculant
Flocculant
To Solvent Extraction
and YeUowcake
Precipitation
To Tailings
Disposal
CCD
Thickener
Flocculant
Wash
H,0
CCD Thickener
Flocculant
CCD
Thickener
mm.
Operating Instructions
Once the Calcine material has been processed in the leach circuit the uranium has
mostly dissolved into the liquid part of the slurry. In order to purify and recover this
dissolved uranium it is necessary to separate the remaining solids from the liquid as
the next processing step.
• At the beginning of your shift, make a safety inspection of all tanks, lines and
equipment.
o Inspect tanks and lines for leaks or seeps.
o Inspect safety showers and eyewash fountains.
o Report any damage or maintenance problem to your supervisor and/or
other appropriate departments.
• If the leach circuit is being operated in the continuous mode, then the
solid/liquid separation step is accomplished by normal operation of the
Counter-current Decantation (CCD) circuit. This separation step is begun by
flowing the leach circuit discharge through the existing pipe line into the CCD
circuit. The CCD circuit is then operated according to normal SOPs with the
possible exception that fewer CCD thickeners may be used than in normal
operation of the plant in the ore processing mode.
No.: PBL-17 DENISON MINING (USA) CORP.
Rev. No.: 1 STANDARD OPERATING PROCEDURES Page 3 of 3
Date: January27, Title: Calcine Solid/Liquid Separation Node
Page 3 of 3
2012
• If the leach circuit is being operated in the batchwise mode, then the
solid/liquid separation step is accomplished in the same tank in which the
leaching was performed, as follows.
o At the conclusion of leaching and before agitation is tumed off, add
flocculant solution to the contents of the tank as instmcted by your
supervisor and allow the agitation of the tank to continue for a brief
time as instmcted by your supervisor. Then tum off agitation to the
tank and allow the contents of the tank to settle.
o As the tank contents sit without agitation, the flocculated solids will
settle to the bottom of the tank, leaving a layer of clear supernatant
liquid above the layer of settled solids. When the settling of solids is
completed, as determined by your supervisor, begin to decant, or
transfer, the clear supernatant liquid to another leach tank as instmcted
by your supervisor, taking special care to not stir up the settled solids.
o Once the supernatant liquid has been transferred, as much as possible,
to another leach tank, add wash water to the settled solids in the
bottom of the leach tank to a volume level in the tank as instmcted by
your supervisor. Tum on agitation in the tank and mix the wash water
and solids thoroughly for a time as instmcted by your supervisor.
o At the conclusion of mixing the wash water and solids and before
agitation is tumed off, add flocculant solution once more to the
contents of the tank as instmcted by your supervisor and allow the
agitation of the tank to continue for a brief time as instmcted by your
supervisor. Then tum off agitation to the tank and allow the contents
of the tank to settle again.
o When the settling of solids is completed, as determined by your
supervisor, decant the clear supematant liquid to another leach tank as
instmcted by your supervisor, taking special care again to not stir up
the settled solids.
o Once the supematant liquid has been transferred, as much as possible,
to another leach tank, add water to the settled solids in the bottom of
the leach tank to a volume level in the tank as instmcted by your
supervisor. Tum on agitation in the tank and mix the water and solids
thoroughly for a time as instmcted by your supervisor. Then transfer
the contents of the tank to tailings disposal, discharging through the
valve at the bottom of the leach tank as instmcted by your supervisor.
o Mix and dilute the combined decanted supematant liquid to prepare it
for feeding to the Solvent Extraction (SX) circuit, as instmcted by your
supervisor. Then transfer the solution to another tank for feeding to
the SX circuit, as instmcted by your supervisor.
ATTACHMENT 3
Revisions to KF SOP
11
No.:
Rev. No.: R-l
Date: June 14, 2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Carbonate Digest Node
Page 1 of3
Hazard Assessment Worksheet Node #3
Equipment Component KF Carbonate Digest Node
Individual Equipment No.
Parameter per Tank Process Material in Component
PFD Na2C03 H2O2
Quantity in Equipment (lb) 73,500 100
Concentration (%) 11 50
Flashpoint, °F — —
TLV-TWA mg/m'
STEL mg/m'
Radioactivity, pCi/g 0 0
Temperature, °C 85°C Amb
Pressure, psig 0 0-20
Health Rating
Health Hazard
Assessment Description: This solution of Na2C03 will be made up in place in one of the leach tanks
from the dry soda ash in super sacks. All personnel should avoid breathing soda ash dust or any
other contact with the dust from the soda ash. The soda ash is a strong base and can cause chemical
bums. Also, the H2O2 is a powerful oxidizing agent and can rapidly cause chemical bums to
anything it touches. Operators and anyone in the area should wear proper PPE to protect from
these chemicals. In case of any contact, wash the area of contact off with generous amounts of
water.
NajCOg
Steam
H202
#3 Leach
Tank
Operating Instructions
This node deals with the carbonate digestion of the residue remaining after multiple
batches of water leaching of the KF material.
No.:
Rev. No.: R-l
Date: June 14,2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Carbonate Digest Node
Page 2 of3
• Obtain approval from your supervisor to run the carbonate digestion step of
processing on the accumulated residue from multiple batches of water leaching of
the KF material.
• Make a safety inspection of all lines and equipment.
o Inspect lines for leaks or seeps.
o Inspect safety showers and eyewash foimtains
o Always keep your work area clean and ensure your area is free of
hazardous obstmctions. Always read and follow all parameters listed on
the MSDS. This means that you must read and understand the information
on the MSDS and ifyou don't, ASK YOUR SUPERVISOR.
• Add water to the accumulated residue from multiple batches of water leaching in
one of the leach tanks to the tank level as instmcted by your supervisor, then tum
on agitation. Add soda ash from super sacks to the contents of the leach tank to a
Na2C03 concentration of 120 g/1 or as instmcted by your supervisor. Add steam to
the contents of the leach tank to a temperature of 85°C, or as instmcted by your
supervisor. Add any required hydrogen peroxide to the leach tank as instmcted
by your supervisor.
• Maintain digestion conditions and agitation in the leach tank for 6 hours or as
instmcted by your supervisor.
• Make certain any required sample is taken when the tank agitator is on and the
digestion has been completed.
• Just prior to shutting off agitation in the leach tank, add flocculant to the contents
of the leach tank as instmcted by your supervisor. Separate undissolved solids by
turning off the agitator and allowing the solids to settle to the bottom of the leach
tank.
• Once solids in the leach tank have settled sufficiently, operate the decant pump
and transfer the clear solution from the top of the tank to another leach tank as
instmcted by your supervisor. Make sure that none of the settled solids are
transferred with the clear solution during the decantation process.
• Depending on the m-anium content of the remaining solids in the leach tank, either
repeat the carbonate digestion step or add water and repulp and wash any
dissolved uranium from the remaining solids in the leach tank, as instmcted by
your supervisor. Following the repulp and wash, add flocculant and settle the
solids and decant the clear solution to another leach tank as instmcted by your
supervisor.
No.:
Rev. No.: R-l
Date: June 14,2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Carbonate Digest Node
Page 3 of3
Once the solids remaining in the leach tank have been sufficiently leached and
washed, discharge the remaining solids from the bottom of the leach tank to
tailings as instmcted by your supervisor.
Be sure to wear appropriate PPE at all times when working on or around this
process.
Always keep your work area clean and free of obstmctions.
No.:
Rev. No.: R-l
Date: June 14, 2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Caustic Precipitation Node
Page 1 of3
Hazard Assessment Worksheet Node #5
Equipment Component
Individual Equipment No.
KF Caustic Precipitation Node
Parameter per Tank Process Material in Component
PFD Uranium Sodium
Carbonate
NaOH
Quantity in Equipment (lb) 3,500 85,000 14,500
Concentration (%) 11 50
Flashpoint, °F — ~
TLV-TWA ppm
STEL ppm
Radioactivity, pCi/g
Temperature, °C 70 70 Amb
Pressure, psig 0-20 0-20 0-20
Health Rating
Health Hazard
Assessment Description: A uranium-rich precipitate is formed by NaOH addition to the
solution from the carbonate digestion of the KF water leach residue in this processing
step. The liquid in the tank is strongly basic. Any splashing or contact with the skin
should be avoided. These materials can cause skin and eye bums. The solution and
the precipitate that is formed are also radioactive and you must follow established
health physics controls. If any ofthe solution or precipitate gets on you, wash it off
with generous amounts of soap and water.
I NaOH I—I
m ite Leach
Tank
Liquor from Carbonate
Leach of KF Residue
after Water Leach
Decant to
Tailings
No.:
Rev. No.: R-l
Date: June 14,2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Caustic Precipitation Node
Page 2 of3
Operating Instructions
This node deals with formation of a uranium-rich precipitate by addition of
NaOH to the solution from the carbonate digestion of the residue after water
leach of the KF material.
• Make a safety inspection of all lines and equipment.
o Inspect lines for leaks or seeps.
o Inspect safety showers and eyewash fountains
• Maintain agitation of the filtrate solution from carbonate digestion of
the residue after water leach of the KF material in the leach tank. Add
steam, if necessary, to maintain the contents of the precipitation tank at
least at 70°C (158°F) or as instmcted by your supervisor.
• Make sure you are wearing all appropriate PPE for handling 50%
NaOH (caustic) solution.
• To the agitated contents of the precipitation tank carefully add 50%
NaOH (caustic) solution until the pH of the contents of the tank
reaches at least 13.0 or as instmcted by your supervisor. Measure the
pH ofthe tank contents with pH paper obtained from the lab. Do not
measure the pH using an ordinary pH meter and probe - these may not
give correct pH readings in this solution.
• After the contents of the tank reach the target pH, continue for about 4
hours to agitate the tank contents at the target temperature and
continue to carefully add small volumes of the 50% NaOH solution to
the tank as necessary to maintain the target pH or as instmcted by your
supervisor.
• After about four hours, the precipitation reaction should be complete.
At this point add to the slurry in the precipitation tank the amount of
flocculant as instmcted by your supervisor. Maintain agitation briefly
after flocculant addition to mix the flocculant into the contents of the
tank. Then tum off agitation and allow the solids to settle to the
bottom of the tank.
• Once solids in the leach tank have settled sufficiently, operate the
decant pump and transfer the clear solution from the top of the tank to
tailings as instmcted by yoiu* supervisor. Make sure that none of the
settled solids are transferred with the clear solution during the
decantation process.
No.:
Rev. No.: R-l
Date: June 14,2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Caustic Precipitation Node
Page 3 of3
• After decanting all possible clear solution from the leach tank, add
water and repulp and wash the precipitate solids in the leach tank, as
instmcted by your supervisor. Following the repulp and wash, add
flocculant and settle the solids and decant the clear solution to tailings
as instmcted by your supervisor. Make sure that none of the settled
solids are transferred with the clear solution during the decantation
process. Repeat this repulp and wash step as needed as instmcted by
your supervisor.
• Whenever working in, around or on this process you must avoid
splashing and any contact with the skin and YOU MUST wear PPE
which includes at a minimum, hard hat, coveralls, mbber boots and
gloves, safety glasses with side shields, and whatever level of
respiratory protection is deemed appropriate by the Radiation Safety
Officer, and may include a face shield or safety goggles.
No.:
Rev. No.: R-l
Date: June 14,2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Acid Re-Dissolve Node
Page 1 of2
Hazard Assessment Worksheet Node #6
Equipment Component
Individual Equipment No.
KF Acid Re-Dissolve Node
Parameter per Tank Process Material in Component
PFD Uranium Sulfuric Acid
Quantity in Equipment (lb) 3,500 3,400
Concentration (%) 93
Flashpoint, °F —
TLV-TWA ppm
STEL ppm
Radioactivity, pCi/g 0
Temperature, °C 25-40 25-40
Pressure, psig 0-20 0-100
Health Rating
Health Hazard
Assessment Description: The re-pulped basic uranium-rich precipitate and the acidic
solution in which it will be re-dissolved should be handled with caution. Any splashing or
contact with the skin should be avoided. The acidic chemicals in the liquid can cause
skin and eye bums. The solution and the filter cake are also radioactive and you
must follow established health physics controls. If any of the solution or filter cake
gets on you, wash it off with generous amounts of soap and water.
m
To Normal SX
and Yellowcake
Production
No.:
Rev. No.: R-l
Date: June 14,2012
INTERNATIONAL URANIUM (USA) CORPORATION
STANDARD OPERATING PROCEDURES
Title: KF Acid Re-Dissolve Node
Page 2 of2
Operating Instmctions
This node deals with the acid re-dissolution of re-pulped uranium-rich
precipitate.
• Make a safety inspection of all equipment.
o Inspect safety showers and eyewash foimtains
o Inspect valves and fittings in the acid line.
• Add water to the settled uranium precipitate solids in the bottom of the
leach tank to the level as instmcted by your supervisor. Tum on
agitation in the tank as soon as the level is sufficient according to your
supervisor's instmctions.
• Carefully add sulfuric acid to the agitated repulped precipitate to bring
the pH of the slurry to 2.0 or another pH as instmcted by your
supervisor.
• Add steam to bring the contents of the acid re-dissolution leach tank to
40°C or another temperature as instmcted by your supervisor. Agitate
the slurry in the tank at the target temperature and pH for a time of at
least one hour as instmcted by your supervisor, adding steam and
sulfuric acid as needed to maintain these conditions.
• Pump the solution from the acid re-dissolved uranium precipitate to
The SX circuit to be combined with the feed stream into normal SX
processing and other downstream yellowcake production as described
in existing SOPs.
• Whenever working in, around or on this process you must avoid
splashing and any contact with the skin and YOU MUST wear PPE
which may include hard hat, coveralls, mbber boots and gloves, safety
glasses with side shields, and whatever level of respiratory protection
is deemed appropriate by the Radiation Safety Officer, and may
include a face shield or safety goggles.