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Home My WebLink AboutDRC-2012-001696 - 0901a068802f7a71DENISON MINES Dii Pf!C-20I2-D01696 Denison Mines Corp 6425 S Highway 191, PO Box 809 Blanding. UT 84511 USA Tel 435 678-2221 Fax 435 678-2224 www denisonmines com VIA EMAIL AND FEDERAL EXPRESS July 16, 2012 Mr Rusty Lundberg Director Utah Division of Radiation Control State of Utah Department of Environmental Quality 168 North 1950 West Salt Lake City, UT 84114-4850 Re. Response to Email Request of July 5, 2012 Regarding Radiological Data for March 25, 2012 Dear Mr Lundberg This letter responds to the email request which Denison Mines (USA) Corp ("Denison") received from Mr Kevin Carney of the Utah Division of Radiation Control ("DRC") on July 5, 2012 regarding Denison's June 27, 2012 letter to the Division of Air Quality descnbing a temporary imbalance in the leach Circuit on March 25, 2012 Specifically, Mr Carney 1 Stated DRC's concern regarding the release of any radioactive matenal dunng the event, 2 Requested that Denison forward any radiological sample data available for this event, and 3 Stated that DRC disagrees that particulates, dust, and airborne solids can be ascertained through human observation No Release of Radiological Material Based on all the information collected regarding the event, as provided below, Denison has determined that no measurable level of radioactive matenal was released dunng the event Denison submits the following information relative to radionuclides and radiation monitonng on and around the date of the event Radiological Data Alpha Radiation Safety Officer David Turk, and Safety Manager Wayne Palmer entered the leach plant dunng the event on March 25, 2012 and were in intimate contact with the CO/NOx vapors in the building That is, they stood directly inside vapors on and near the leach tanks Both of them scanned themselves, their clothing, their personnel protective equipment, and Draeger tube sampling devices with one of the Mill's personnel scanning 177 alpha meters when they left the leach area Both recorded zero alpha contamination above background on their persons, clothing, PPE, samples, sample devices, and samples That is, there was no detectable alpha contamination released dunng the event Daily efficiency check data for each of the Mill's alpha meters is provided in Attachment 1 Beta/Gamma Routine monthly beta/gamma results were collected in the leach area on March 28, (three days after the event) Monthly beta/gamma data for March 2012, the month of the leach event, are lower than results for February 2012 That is, there was no measurable increase in gamma radiation due to the event Beta/gamma reports for the months of February and March 2012 are provided in Attachment 2 Radon Routine monthly radon progeny concentration data (assessed in Working Levels ("WLs")) was measured in the leach area on February 10, 2012 and March 30, 2012 Monthly radon progeny results for March 2012, the month of the leach event, are lower than results for February 2012 (The WL value for the month of March was zero) That is, there was no measurable increase in radon progeny due to the event Radon Progeny Concentration Reports for the months of February and March 2012 are provided in Attachment 3 Radioactive Particulates Monthly area airborne particulate filters, including BA-8 located in the leach area, were collected and counted on March 5, 2012 (before the event) and Apnl 6, 2012 (after the event) Airborne activity concentration was reported as 0 uCi/mL for both months That is, there was no measurable increase in airborne radioactive particulates due to the event Monthly area airborne sampling data for the measurements in March and Apnl 2012 are provided in Attachment 4 Human Observation of Particulate Opacity Contrary to DRC's assertion in the email of July 5, 2012, that the presence of particulates cannot be ascertained by direct human observation, 40 CFR 60, Appendix A, Method 9 Visible Emissions Evaluation, and Utah R307-201-3, expressly require that particulate opacity be determined by direct human observation by a trained and certified observer The Mill's Utah Air Approval Order, in Part II B 1 d, requires that measurement of particulate opacity be performed per 40 CFR Appendix A Method 9, by direct human observation Mill Safety Manager Wayne Palmer, a currently-certified opacity observer per U S EPA Method 9 who was present as a responder to the CO/NOx event, observed no particulate opacity Please contact me if you have any further questions or require any further infomnation Yours very truly. Jo Ann Tischler Director, Compliance and Permitting DENISON MINES (USA) CORP. DENISO MINES Jiii CC Bryce Bird, Utah Division of Air Quality Kevin J Carney, Utah Division of Radiation Control David C Frydenlund Dan Hillsten Sarah Malluche, Utah Division of Air Quality Harold R Roberts David Turk KathenneA Weinel Denison Central Files DENISO MINES ATTACHMENT 1 Daily Efficiency Checks 177 Alpha Meters DENISO MINES Jiii Daily Efficiency checks 177 Alpha Meters Date Instrument Model Senal # Location Rad Tech Alarm Background \11'Q\ ^^74o 5o Th 230 SNg;99^-o 9 DPM .-^^jcyr^ CPM -Z^£iO EFF 9 0^. Alpha Meter EFF Factor JfO.^ Cal Date ^Jjf^l/Z^ MDA Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background /?? .^^ Th 230 SN ^^^i'O^ DPM_^^^^ CPM '^GVO EFF ^.Q-y., Alpha Meter EFF Factor Cal Date c2^f;€:f// MDA .^9-^ 3 Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background Th 230 SN Alpha Meter EFF Factor /f ^ DPM_^3^^£_ CPM EFF J-/ Cal ^^X^JJlALCiL MDA 7/7 Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background J72 70 ^0 Th230SNj£2^^f^:^ DPM 33.tJ^£? EFF Alpha Meter EFF Factor o^^fP Cal Date H <hny/jL MDA ^/D Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background m Th 230 SN.<9:^--^^ DPM ^"^^^CxP ) CPM EFF g.f 7 Alpha Meter EFF Factor Cal Date MDA S/n Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background UV Th 230 SN 5^)94^^^^ DPM CPM EFF ^r^y, Alpha Meter EFF Factor>^o2 <A Cal Date^^/^/^ MDA Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background Alpha Meter Th 230 SN f'9^^<^l>^ EFF Factor cJ^ DPM CP M_3i^^^:^_ EFF '9 ^-^^ Cal Date MDA ,^9^ Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background Th 230 SN. DPM CPM EFF Alpha Meter EFF Factor Cal Date MDA Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background Alpha Meter Tn 2iU bN EFF Factor DPM Cal Date CPM MDA EFF Daily Efficiency checks 177 Alpha Meters Date Instrument Model Serial # Location Rad Tech Alarm Background Th 230 SN. DPM CPM EFF Alpha Meter EFF Factor Cal Date MDA ATTACHMENT 2 Beta/Gamma Data Sag Mill/Leach Areas DENISO MINES Jiii to QJ JC u 03 o 0 <S •I 0 4| ro E £ ro OJ CO I rr> >. > to 4 c t^ 01 *-> 4-> ro Q PA Q E I- < CO CD (U U 03 0) — 00 i. 2 — bO 5 s -= ao m 0 (§1 < C-0 Ro o m OJ in c h Sh i f t e r ' s O f f i c to r ' s L t Sh i f t e r ' s O f f i c Op e r a i •D •o O o Ci ft o ATTACHMENT 3 Radon Progeny Concentration Reports February and March 2012 DENISO MINES Jiii Radon Progeny Concentration Report for February 2012 Sampled By; Radiation Department Sample Date Sample No. Station Elpsd. Time Count Time Total Cnt. CPM Bkg. Net CPM Instr. Model Time Fctr. Eff. Fctr. Vol. (v) Total Vol. (V) Working Level Comments Sample Date Sample No. Station Elpsd. Time CT TC (TC/ CT) Bkg. CPM- Bk§. 2200 or 2929 TF EF L/Mm V=v*Ts (litre) (Net CPM*EF)/ (TF*V) 02/10/12 BAl Scalehouse 57 1 3 3 00 69 0 00 2929 116 4 09 4L 20 OOOO Monthly Samples 02/10/12 BA2 Ore Storage 60 1 9 9 00 69 2 07 2929 110 4 09 4L 20 0 004 02/10/12 BA6 Sample Plant 62 1 7 7 00 69 0 07 2929 106 4 09 4L 20 OOOO 02/10/12 BA7 SAG Mill 70 1 4 4 00 69 0 00 2929 90 4 09 4L 20 OOOO 02/10/12 BA8 Leach 65 1 29 29 00 69 22 07 2929 100 4 09 4L 20 0 045 02/10/12 BA9 CCD Circuit 48 1 6 6 00 69 0 00 2929 134 4 09 4L 20 OOOO 02/10/12 BAIO SX Building 50 1 5 5 00 69 0 00 2929 130 4 09 4L 20 OOOO 02/10/12 BA12 Y C Precip 51 1 5 5 00 69 0 00 2929 128 4 09 4L 20 OOOO Average - 0 004 02/10/12 BAI2A NYC Dryer Encl 50 1 10 10 00 69 3 07 2929 130 4 09 4L 20 0 005 Highest - 0 045 02/10/12 BA12B S Y C Dryer Encl 58 1 9 9 00 69 2 07 2929 114 4 09 4L 20 0 004 Area is Locked 02/10/12 BA13 Y C Drying Area 61 1 5 5 00 69 0 00 2929 108 4 09 4L 20 OOOO 02/10/12 BA13A Y C Pckg Encl 63 1 5 5 00 69 0 00 2929 104 4 09 4L 20 OOOO 02/10/12 BAM Y C Storage 65 1 7 7 00 69 0 07 2929 100 4 09 4L 20 oooo 02/10/12 BAl 5 Bucking Room 58 1 7 7 00 69 0 07 2929 114 4 09 4L 20 oooo 02/10/12 BAl 6 Lunch Room 55 1 13 13 00 69 6 07 2929 120 4 09 4L 20 0 010 02/10/12 BAl 7 Change Room 58 1 11 11 00 69 4 07 2929 114 4 09 4L 20 0 007 02/10/12 BAl 8 Admin Bldg 50 1 5 5 00 69 0 00 2929 130 4 09 4L 20 oooo 02/10/12 BAl 9 Warehouse 50 1 9 9 00 69 2 07 2929 130 4 09 4L 20 0 003 02/10/12 BA20 Maint Shop 52 1 1 1 00 69 0 00 2929 126 4 09 4L 20 oooo 02/10/12 BA21 Boiler 74 1 7 7 00 69 0 07 2929 84 4 09 4L 20 oooo 02/10/12 BA22 Vanadium Panel 63 1 7 7 00 69 0 07 2929 104 4 09 4L 20 oooo 02/10/12 BA22A Vanadium Dryer 67 1 14 14 00 69 7 07 2929 96 4 09 4L 20 0015 02/10/12 BA23 Van Fltr Belt 72 1 16 16 00 69 9 07 2929 87 4 09 4L 20 0 021 02/10/12 BA24 Tails 70 1 8 8 00 69 1 07 2929 90 4 09 4L 20 0 002 02/10/12 BA25 Control Room 55 1 11 11 00 69 4 07 2929 120 4 09 4L 20 0 007 02/10/12 BA26 Shifter's Office 70 1 5 5 00 69 0 00 2929 90 4 09 4L 20 OOOO 02/10/12 BA27 Oper's LR 71 1 12 12 00 69 5 07 2929 89 4 09 4L 20 0 012 \ 02/10/12 BA29 Generator Station, 69 1 6 6 00 69 0 00 2929 92 4 09 4L 20 OOOO 02/10/12 BA30 Truck Shop i 75 1 8 8 00 69 1 07 2929 83 4 09 4L 20 0 003 02/10/12 BA31 Womens Locker Rni 53 1 9 9 00 69 2 07 2929 124 4 09 4L 20 0 003 ' (F ' 02/10/12 BA32 Oxidation i 65 1 11 11 00 69 4 07 2929 100 4 09 4L 20 0 008 02/10/12 BA33A AF Dump Station 75 1 6 6 00 69 0 00 2929 83 4 09 4L 20 OOOO 02/10/12 BA33B North AF PAD 77 1 5 5 00 69 0 00 2929 81 4 09 4L 20 OOOO Radon Progeny Concentration Report for March 2012 Sampled By; Radiation Department Sample Date Sample No. Station Elpsd. Time Count Time Total Cnt. CPM Bkg. Net CPM Instr. Model Time Fctr. Eff. Fctr. Vol. (v) Total Vol. (V) Working Level Comments Sample Date Sample No. Station Elpsd. Time CT TC (TC/ CT) Bkg. CPM- Bkg. 2200 or 2929 TF EF L/Min V=v*Ts (litre) (Net CPM*EF)/ (TF*V) 03/30/12 BAl Scalehouse 61 1 4 4 00 69 0 00 2929 105 4 09 4L 20 OOOO Monthly Samples 03/30/12 BA2 Ore Storage 60 1 7 7 00 69 0 07 2929 110 4 09 4L 20 oooo 03/30/12 BA6 Sample Plant 56 1 11 11 00 69 4 07 2929 118 4 09 4L 20 0 007 03/30/12 BA7 SAG Mill 65 1 5 5 00 69 0 00 2929 100 4 09 4L 20 OOOO 03/30/12 BA8 Leach 67 1 3 3 00 69 0 00 2929 96 4 09 4L 20 oooo 03/30/12 BA9 CCD Circuit 74 1 7 7 00 69 0 07 2929 84 4 09 4L 20 oooo 03/30/12 BAIO SX Building 73 1 7 7 00 69 0 07 2929 85 4 09 4L 20 oooo 03/30/12 BA12 Y C Precip 83 1 9 9 00 69 2 07 2929 71 4 09 4L 20 0 006 Average- Ojm^'^-'f 03/30/12 BA12A NYC Dryer Encl 74 1 13 13 00 69 6 07 2929 84 4 09 4L 20 0 015 Highest - 0 021 03/30/12 BA12B S Y C Dryer Encl 78 1 15 15 00 69 8 07 2929 78 4 09 4L 20 0 021 Area is Locked 03/30/12 BAl 3 Y C Drying Area 77 1 8 8 00 69 1 07 2929 81 4 09 4L 20 0 003 03/30/12 BA13A Y C Pckg Encl 87 1 8 8 00 69 1 07 2929 65 4 09 4L 20 0 003 03/30/12 BAH Y C Storage 75 1 9 9 00 69 2 07 2929 83 4 09 4L 20 0 005 03/30/12 BAl 5 Bucking Room 70 1 9 9 00 69 2 07 2929 90 4 09 4L 20 0 005 03/30/12 BA16 Lunch Room 59 1 9 9 00 69 2 07 2929 112 4 09 4L 20 0 004 03/30/12 BA17 Change Room 57 1 10 10 00 69 3 07 2929 116 4 09 4L 20 0 005 03/30/12 BAl 8 Admin Bldg 60 1 6 6 00 69 0 00 2929 110 4 09 4L 20 OOOO 03/30/12 BA19 Warehouse 52 1 8 8 00 69 1 07 2929 126 4 09 4L 20 0 002 03/30/12 BA20 Maint Shop 54 1 4 4 00 69 0 00 2929 122 4 09 4L 20 OOOO 03/30/12 BA21 Boiler 60 1 3 3 00 69 0 00 2929 110 4 09 4L 20 OOOO 03/30/12 BA22 Vanadium Panel 80 1 8 8 00 69 1 07 2929 75 4 09 4L 20 0 003 03/30/12 BA22A Vanadium Dryer 81 1 9 9 00 69 2 07 2929 74 4 09 4L 20 0 006 I 03/30/12 BA23 Van Fltr Belt 83 1 6 6 00 69 0 00 2929 71 4 09 4L 20 OOOO 03/30/12 BA24 Tails 62 1 9 9 00 69 2 07 2929 106 4 09 4L 20 0 004 03/30/12 BA25 Control Room 82 1 10 10 00 69 3 07 2929 73 4 09 4L 20 0 009 A 1." / 03/30/12 BA26 Shifter's Office 79 1 9 9 00 69 2 07 2929 76 4 09 4L 20 0 006 r / 03/30/12 BA27 Oper's LR 80 1 5 5 00 69 0 00 2929 75 4 09 4L 20 OOOO 03/30/12 BA29 Generator Station 81 1 4 4 00 69 0 00 2929 74 4 09 4L 20 OOOO • r 03/30/12 BA30 Truck Shop 63 1 7 7 00 69 0 07 2929 104 4 09 4L 20 OOOO 03/30/12 BA31 Womens Locker Rm 54 1 7 7 00 69 0 07 2929 122 4 09 4L 20 oooo 03/30/12 BA32 Oxidation 62 1 5 5 00 69 0 00 2929 106 4 09 4L 20 OOOO 03/30/12 BA33A AF Dump Station 64 1 4 4 00 69 0 00 2929 102 4 09 4L 20 oooo 03/30/12 BA33B North AF PAD 60 1 9 9 00 69 2 07 2929 110 4 09 4L 20 0 004 03/30/12 BA33C CaFo DumoStation 71 1 12 17 Ofl (S q S 07 9Q9Q so A HQ A T on A f*1 O ATTACHMENT 4 Monthly Area Airbome Sampling Field Sheet DENISO MINES Jiii Month March-12 Monthly Area Airborne Sampling Field Sheet Denison Mines (USA) Corp. White Mesa Mill Sampled By: Radiation Department Filter Location Run Time Flow Rate Volume Sampled Comments ID Date (Min.) (LPM) (mL) By Comments BA-1 Scalehouse 03/05/12 60 40 2 40E+06 JP Collected on desk in front room BA-2 Ore Storage 03/05/12 60 40 2 40E+06 JP Collected near the pandora ore storage BA-7 Sag Mill 03/08/12 60 40 2 40E+06 JP Sample taken during non Operation tune BA-8 Leach 03/07/12 60 40 2 40E+06 JP Collected above Pre-Leach tanks Air Particulate Calculations Summary Sheet Reviewed by Count Date/Time Filter ID Instrument Serial No Efficiency Total Count/Time CPM Bkg Count/Time Net Count (Tot-Bkg) LLD (uCi/mL) Concentration uCi/ mL Percent of DAC Sample Counted By 03/08/12 BAl 2200 27 19% 226 22 6 16 23 6 37 4 29E-12 4 40E-12 7 33% RN 03/08/12 BA2 2200 27 19% 59 59 7 27 0 00 2 93E-12 0 OOE+00 0 00% RN 03/11/12 BAT 2200 27 19% 122 12 2 16 23 0 00 4 29E-12 0 OOE+00 0 00% RN 03/10/12 BA8 2200 27 19% 121 12 1 16 23 0 00 4 29E-12 0 OOE+00 0 00% RN Concentration ( pCi/cc)= (Net CPM) (2 22 E6)(V)(EfFd) LLD or MDA= 2 71+3 29 \/ Bkg *Ts(l+Ts/T"b) (Ts)(Eff d)(Eff f)(FF)(V)(2 22E6) Ts= Time of Sample Tb= Background Count Time in Minutes Eff d= Detector efficiency in Counts per Dismtegration EfiF f = Filter Efficeincy V= Total Volume m miUilitres or Cubic Centimeters 2 22E6 = Factor to convert DPM to uCi Net CPM = Total Counts - Background Count Percent of DAC= Actual Concentration DAC Month Apnl-12 Monthly Area Airborne Sampling Field Sheet Denison Mines (USA) Corp. White Mesa Mill Sampled By: Radiation Department Filter Location Run Time Flow Rate Volume Sampled Comments ID Date (Mm.) (LPM) (mL) By Comments BA-1 Scalehouse 04/06/12 60 40 2 40E+06 JP Collected on desk m front room BA-2 Ore Storage 04/06/12 60 40 2 40E+06 JP Collected near the pandora ore storage BA-7 Sag Mill 04/05/12 60 40 2 40E+06 JP Sample taken during non Operation time BA-8 Leach 04/05/12 60 40 2 40E+06 JP Collected above Pre-Leach tanks Air Particulate Calculations Summary Sheet Reviewed by Count Date/Time Filter ID Instrument Senal No Efficiency Total Count/Time CPM Bkg Count/Tune Net Count (Tot-Bkg) LLD (uCi/mL) Concentration uCi/mL Percent of DAC Sample Coimted By 04/09/12 BAl 3030 23 75% 15 1 5 12 00 0 00 4 25E-12 0 OOE+00 0 00% RN 04/09/12 BA2 2929 23 66% 75 75 7 27 0 23 3 37E-12 0 OOE+00 0 00% RN 04/08/12 BAT 2929 23 66% 87 87 6 47 2 23 3 19E-12 0 OOE+00 0 00% RN 04/08/12 BA8 2200 26 98% 58 58 15 73 0 00 4 26E-12 0 OOE+00 0 00% RN Concentration ( pCi/cc)= (Net CPM) (2 22 E6)(V)(Effd) LLD or MDA= 2 71+3 29 V Bkg •Ts(l+Ts/Tb) (Ts)(Eff d)(Eff f)(FF)(V)(2 22E6) Ts= Time of Sample Tb= Background Coimt Time m Mmutes Eff d= Detector efficiency m Coimts per Dismtegration Eff f= Filter Efficemcy V= Total Volume m millilitres or Cubic Centimeters 2 22E6 = Factor to convert DPM to uCi Net CPM = Total Counts - Background Count Percent of DAC= Actual Concentration DAC