ML15084A138

Submittal of the Annual Radiological Environmental Monitoring Report Per 10 CFR 72.44(d)(3), for the Three Mile Island Unit 2 Independent Spent Fuel Storage Installation, Docket 72-20 (EM-FMDP-15-011)

ML15084A138
Person / Time
Site:	Three Mile Island, 07200020
Issue date:	02/27/2015
From:	Ahrendts S R US Dept of Energy, Idaho Operations Office
To:	Document Control Desk, Office of Nuclear Material Safety and Safeguards
References
DE-AC07-05ID14516, EM-FMDP-15-011 DOE/ID-10739 (2014)
Download: ML15084A138 (10)

Text

2 Department of EnergyIdaho Operations Office1955 Fremont AvenueIdaho Falls, ID 83415February 27, 2015U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001

SUBJECT:

Submittal of the Annual Radiological Environmental Monitoring Report per 10 CFR72.44(d)(3), for the Three Mile Island Unit 2 Independent Spent Fuel StorageInstallation, Docket 72-20 (EM-FMDP-15-011)

Dear Sir or Madam:

The Department of Energy-Idaho Operations Office hereby submits the Annual RadiologicalEnvironmental Monitoring Report per 10 CFR 72.44(d)(3) for the Three Mile Island Unit 2Independent Spent Fuel Storage Installation (ISFSI) (Docket 72-20). This report coversoperation at the ISFSI for calendar year 2014.If you have any questions please call me at (208) 526-8888.Sincerely,Steven R. AhrqndtsNRC Licensed Facilities DirectorEnclosurecc: U.S. NRC Region IV w/attachG. Hall, CWIW " S S-DýP DOEIID-10739 (2014)Annual Radiological Environmental MonitoringProgram Report forthe Three Mile Island, Unit 2Independent Spent Fuel Storage InstallationG. G. Hall, CHPPublished February 2015Idaho National LaboratoryIdaho Nuclear Technology and Engineering CenterIdaho Falls, Idaho 83415Prepared for theU. S; Department of EnergyAssistant Secretary forEnvironmental ManagementUnder DOE Idaho Operations OfficeContract DE-AC07-051 D14516 ABSTRACTThis report presents the results of the 2014 Radiological Environmental MonitoringProgram condlucted in accordance with 10 CFR 72.44 for the Three Mile Island, Unit 2,Independent Spent Fuel Storage Installation. A description of the facility and themonitoring program is provided. The results of monitoring the two predominantradiation exposure pathways, potential airborne radioactivity releases and direct radiationexposure, indicate the facility operation has not contributed to any increase in theestimated maIximaum potential dose commitment to the general public.2 SUMMARYThe purpose of this report is to present the results of the Radiological EnvironmentalMonitoring Program (REMP) conducted during 2014 for the Three Mile Island, Unit 2,(TMI-2), Independent Spent Fuel Storage Installation (ISFSI). TMI-2 core debris wastransferred to the ISFSI between Marth 1999 and April2001 and remains in interimstorage at the ISFSI.The REMP was implemented from January through December 2014. Results of the loosesurface radioactive contamination surveys indicated no hicrease in either beta or Cs-B37radioactivity attributed to the facility operation. The results of the airborne radioactivitysampling did not indicate releases of airborne particulate radioactivity from the loadedHorizontal Storage Modules (HSM) that would contribute to an increase in the estimatedmaximum potential dose commitment to, the general public. The results oF thethermoluminescent dosimetry network did not indicate an increase in radiation levelsabove pre-operational background attributed to the facility operation.The monitoring program results support the conclusion reached in the FinalEnvironmental Impact Statement that operation of the facility will not result in asignificant dose commitment to the Maximum Exposed Individual.3 CONTENTSA B ST R A C T ................................................................................................................................. 2SU M M AA R Y .................................................................................................................................3IN T R O D U C T IO N ....................................................................................................................... 5PROGRAM DESCRIPTION .................................................................................................. 5R E S U L T S ..................................................................................................................................... 6D IS C U S SIO N .................................................................. ......................................................... 8CONCLUSION ........ .. ...... ..................: .: ... .......................................... 8REFERENCES "............................... ..9FIGURES1. TM I-2 ISFSI TLD Station Locations ...................................................................... ...........6TABLES1. TMI-2 ISFSI Air Sample Results (pCi/r).... ................................................ 72. TMI-2 ISFSI TLD Results (mre ./d) ................... .................. 74 Annual Radiological Environmental MonitoringProgram Report for the Three Mile Island, Unit 2,Independent Spent Fuel Storage InstallationINTRODUCTIONTile Three Mile Island, Unit 2, Independent Spent Fuel Storage Installation (TMI-2 ISFSJ) is aspent fuel dry storage facility designed for interim storage of the TMI-2 core debris. The TMI-2 ISFSI,.located within the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho NationalLaboratory (INL), is operated by CH2M -WG Idaho, LLC for the Department of Energy (DOE). The.TMI-2 ISFSI was licensed on March 19, 1.999 by the Nuclear Regulatory Commission (NRC) pursuant to10 CFR 72 for authorization to receive, possess, store, and transfer spent fuel and fuel debris, resultingfirom the 1979 TMI-2 accident, for a twenty-year termn." --The TMI-2 ISFSI is a modified NUI-IOMS spent fuel storage system, designated NUHOMS-12T.Each ofthe thirty NUHOMS-12T modules within the facility provide for the horizontal dry storage of upto twelve TMI-2 stainless steel canisters inside a dry shielded canister (DSC) which is placed inside aconcrete horizontal storage module (HSMI). The NUHOMS-12T mnodification includes venting of theDSC through high efficiency particulate air (H-EPA) grade filters during storage. The vent system allowsfor release of hydrogen gas, generated due to radiolysis, and monitoring and/or purging of the systemduring operation.The TMI-2 core debris which had been stored in stainless steel canisters in a fuel pool at the TestArea North (TAN) site within the INL has been transferred to the TMI-2 ISFSI for interim storage. ASettlement Agreement entered into by the State of Idaho, the Department of Energy, and the Departmentof the Navy in October 1995 established a schedule -For commencing core debris transfers by March 31,1999, and completing such transfers by June 1, 2001.3 The first core debris transfer was completed onMarch 31, 1999. Nine additional transfers were completedduring 2000. The remaining nineteentransfers were completed during 2001, with the last one completed on April 20, 2001.A Radiological Environmental Monitoring Program (REMP) was developed for the TMI-2 ISFSIand implemented in accordance with 10 CF.R 72.44. This report presents the REMD.results during theTMI-2 ISFSI operation in 2014.PROGRAM DESCRIPTIONThe REMP is designed to monitor the two predominant radiation exposure pathways inherentwith the facility design: potential airborne radioactivity releases and direct radiation. The airborneradioactivity release pathway is monitored using a combinationofloose surface radioactivecontamination surveys and periodic airborne radioactivity sampling. The direct radiation exposurepathway is monitored using thermoluminescent dosimetry (TLD) located along the outer perimeter fenceof the TMI-2 ISFSI.Loose surface radioactive contain inationsunrveys are performed at the vent and purge ports ofeach DSC as well as the drain port of each loaded HSSM. The survey frequency was monthly during thefirst year, quarterly during the second through fifth years, and is now annually. The frequency coincideswith the radiation monitoring surveil lance schedule required by the TMI-2 ISFSI Technical5 Specifications.". Sample media is analyzed for beta..radioadtivity. Depending on the amount.of betaradioactivity detected, gamma isotopic analysis is either performed for each sample or for an annualsample composite. The presefice of Cs-137 is qualitatively determined (or ql0antitatively as necessary)during the gamma isotopic analysis.Twenty-two TLD stations are located and maintained along the outer perimeter fence of the TMI-2 ISFSI. The TLD station locations are noted in Figure 1. .Dosimetty is changed out on a quarterlyfrequency. The minimum detectable dose is no greater than 10 mremn. Since the TMI-2 ISFSI is locatedamong other non-licensed DOE nuclear facilities, there is no specific control TLD station for the TMI-2ISFSI. The INL Radiological Environmental Monitoring Program does have 27 control TLD stations.located outside the INL boundary.Figure 1. TM1-2 ISFSI TLD Station Locations.40 41 42 43 44 45 46 47N61 30.29 28271 26'125T2414234221120 [1.17 Ai16* .." ,60 TLD Location U A-ir Samtpler'49'flj 94ý 13[1211 1109 8.17] ilK!_31 11 5058 57. 56 5 .54 .53 .52 .51A Iow-volumeair sampler is used to collect air through a particulate filter during a seven-dayperiod each month. The air sampler is located between the two rows of HSMs inside the TMI-2 ISFSI.Each air particulate sample is analyzed for beta radioactivity with a Lower Limit of Detection (LLD) nogreater than 0.01 pCi/m3.Depending on the amount of beta radioactivity detected, gamma isotopicanalysis is either performed for each air particulate sample or for an annual sample composite. Thepresence of Cs-137 is qualitatively determinied (or quantitativ'ely. as necessary) during the gamma isotopicanalysis. Independent airborne radioactivity monitoring stations are maintained off-site of the INL by theINL Environmental Surveillance Program (one station in .Howe, ID), the Idaho Department ofEnvironmental Quality INL Oversight Program :(three distance stations at Crater of the Moon NationalMonument, Fort Hall, ID and Idaho Falls, ID), and the Environmental Protection Agency, Region 10 (onestation in Boise, ID). These stationsare relied upon.as control air sampling stations; the sampling resultsof which are used for comparison purposes..RESULTSThe loose surface contamination survey resu Its for the'purge, vent, and drain ports were less thanthe Minimum Detectable Activity (MDA), 32 dpm/1 00 cm2beta/gamma and 19 dpm/100 cm2alpha,6.

calculated in accordance with NUREG/CR-1 507,2. The gamma isotopic -results for the purge, vent, anddrain port contamination survey composite samples from the HSMs indicated no fission productradioactivity. Cs-137 radioactivity was less than MDA which averaged 1.5E-2 nCi/sample; wellibelowthe required LLD of 5 nCi/sample.Mlonthly air sampling beta radioactivity results for the TMI-2 ISFSI are presented in Table 1.Beta radioactivity was not detected above the established threshold of 4E- 14 LCWi/cc (0.04 pCi/rn3) oneach monthly sample collected during Januaty and March tihrough December. Beta radioactivity for thesample collected in February was detected above the established threshold at 6.1 E- 14 ltCi/cc. Gammaspectroscopy results of the colnposited air samples collectedl throughout the year did not indicate thepresence of fission or activation product activity.Table 1. TMI 1-2 ISFSI Air Sample Results (pCi/mr3).Sample Date Beta .Sample Date Beta.lJnuary 0.01 'Ily' 0.02Februaiw, 0.06 .. August 0.02March 0.01 September 0.02April 0.02 October 0.02MNlay 0.01 November 0.04.lune 0.02 December 0.03TLD results are presented in Table 2 in units of mrem/d. TLD results include an artificialphantom backscatter correction of 3% to expressthe results in dose equivalent units.. Quarterly standarddeviations were between 0.1 rnrem/d and 0.2 mtem/d. Analysis of variance results indicated that duringthe first three quarters, quarterly variances were different than the pre-operational baseline variance.measured in March 1999. During the fourth quarter the variances were equal. T-test results indicatedquarterly mean TLD responses were in all cases significantly lower than the pre-operational baselinemean measured in March 1999 due to introduction of a new environmental dosimeter and processingsystem in June 1999.6 Mean TLD responses ranged from 0.5 to 0.9 mrem/d. Radiation monitoring atother locations within the 100 meter perimeter was not performed due to extremely low buildingoccupancy factors. There were no TLDs unaccounted for during the monitoring period.Table 2. TMI-2 ISFSI TLD Results (mrem/d).LOCATION QI Q2 Q3 Q4 MEAN40 0.7 0.6 0.6 0.6 0.641 0.6 0.6 0.6 0.6 0.642 0.6 0.5 0.5 0.5 0.643 0.6 0.5 0.5 0.5 0.644 0.6 0.5 0.5 0.5 0.545 0.6 0.5- 0.5 0.5 0.546 0.6. 0.5 0.5 0.5 *0.547 0.6 0.5 0.5 0.5 0.548 0.6 0.5 0.5 0.5 0.549 0.6 0.6 0.5 0.6 0.650 0.6 0.6 0.6 0.6 0.65.1 0.8 0.7 0.6 0.7 0.752 0.8 0.7 0.6 0.7 0.753 0.8 0.7 0.7 0.8 0.854 0.8 0.8 0.7 0.8 0.87 Table 2. TMI-2 ISFSI TLD Results (mrern/d) (continued)..LOCATION Q I Q2 Q3 Q4 MEAN55 0.8 0.8 0.7 0.8 0.856 0.9 0.8 " :.0.8 .0.9 0.8.57 0.9 0.8 0.8 0.9 *0.958. 0.9 0.8 0.8 0.9 0.959 0. 0.8 *0.8 0.9' :0.860 0.8 .-0.7' 0.7 0.8 0.761 0.7 0.7 0.7 0.8 0.7MEAN 0.7 0.6 0.6 0.7 0.7DISCUSSIONThe TMI-2 ISFSI REMP Was conducted in accordance with establishecl procedures. There wvereno changes made to the TMI-2 ISFS1 REMP during 2014.The loose surface raclioactive contamination survey results indicate there has been no measurablerelease of raclioactive material from tile DSCs stored in the HSMs at the ISFSI above and beyond thatprojected in the Final Environmental Impact Statement (EIS).7 Radioanalytical results are notsignificantly different from pre-operational results as well as those projected in the EIS.The airborne radioactivity sampling results indicate there has been no measurable release ofradioactive mateiial from the DSCs stored in the HSMs at the ISFSI above and beyond that projected inthe EIS.The radiation dosimetry results indicate there has been no measurable increase in ambientbackground radiation levels outside the TMI-2 ISFSI perimeter fence attributed to storage of the TMI-2core debris. The absence of any significant increase in radiation levels outside the TMI-2 ISFSI perimeterfence also supports conclusions reached in the EIS.Calibration and quality control of instrumentation used for beta analysis of surface contaminationand airborne radioactivity sample media is maintained in accordance with procedLures used by the IdahoCleanup Project (ICP) Radiological Control Program.8 Radioactivity sources used for instrumentationcalibration and quality control are traceable to the National Institute of Standards and Technology (NIST).CONCLUSIONAirborne radioactivity releases and direct radiation exposure from the facility during 2014 did notcontribute to any increase in the estimate of maximum potential dose commitment to the general public;characterized as 2.7E-3. mrem/y to the Maximum Exposed Individual reported in the EIS. There were noradioactive liquid effluents released from the facility, hence no radionuclides to report.8 REFERENCES1. Materials License SNM-2508 for the Three Mile Island, Unit 2, Independent Spent Fuel StorageInstallation (TAC No's L22283 and L22800), March 19, 1999, Docket No. 72-20.2. 10 CFR 72, "Licensing Requirements for the Independent Storage of Spent Nuclear Fuel andHigh-Level Radioactive Waste," Code of Federal Regulations, Office of the Federal Register,October 2004.3. Settlement Agreement between the State of Idaho, Department of the Navy, and the Departmentof Energy, October 16, 1995.4. Technical Specifications and Bases for the INL TMI-2 Independent Spent Fuel StorageInstallation.5. NUREG/CR-1507, "Minimuml Detectable Concentrations with Typical Radiation SurveyInstruments for Various Contaminants and Field Conditions," December 1997.6. P. E. Ruhter, N"ewl Environmental Dosimeter Response, letter PER-i17-99, July 29, 1999.7. NUREG-1626, "Final Environmental Impact Statement for the Construction and Operation of anIndependent Spent Fuel Storage Installation to Store the Three Mile Island Unit 2 Spent Fuel atthe Idaho National Engineering and Environmental Laboratory," Docket No. 72-20, March 1998.8. ICP, Radiological Control 15B and 15C.9