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 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 Energy Idaho Operations Office 1955 Fremont Avenue Idaho Falls, ID 83415 February 27, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

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)

Dear Sir or Madam:

The Department of Energy-Idaho Operations Office hereby submits 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 (ISFSI) (Docket 72-20). This report covers operation at the ISFSI for calendar year 2014.

If you have any questions please call me at (208) 526-8888.

Sincerely, Steven R. Ahrqndts NRC Licensed Facilities Director Enclosure cc: U.S. NRC Region IV w/attach G. Hall, CWI W " SS-DýP

DOEIID-10739 (2014)

Annual Radiological Environmental Monitoring Program Report forthe Three Mile Island, Unit 2 Independent Spent Fuel Storage Installation G. G. Hall, CHP Published February 2015 Idaho National Laboratory Idaho Nuclear Technology and Engineering Center Idaho Falls, Idaho 83415 Prepared for the U. S; Department of Energy Assistant Secretary for Environmental Management Under DOE Idaho Operations Office Contract DE-AC07-051 D14516

ABSTRACT This report presents the results of the 2014 Radiological Environmental Monitoring Program 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 the monitoring program is provided. The results of monitoring the two predominant radiation exposure pathways, potential airborne radioactivity releases and direct radiation exposure, indicate the facility operation has not contributed to any increase in the estimated maIximaum potential dose commitment to the general public.

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SUMMARY

The purpose of this report is to present the results of the Radiological Environmental Monitoring Program (REMP) conducted during 2014 for the Three Mile Island, Unit 2, (TMI-2), Independent Spent Fuel Storage Installation (ISFSI). TMI-2 core debris was transferred to the ISFSI between Marth 1999 and April2001 and remains in interim storage at the ISFSI.

The REMP was implemented from January through December 2014. Results of the loose surface radioactive contamination surveys indicated no hicrease in either beta or Cs-B37 radioactivity attributed to the facility operation. The results of the airborne radioactivity sampling did not indicate releases of airborne particulate radioactivity from the loaded Horizontal Storage Modules (HSM) that would contribute to an increase in the estimated maximum potential dose commitment to, the general public. The results oF the thermoluminescent dosimetry network did not indicate an increase in radiation levels above pre-operational background attributed to the facility operation.

The monitoring program results support the conclusion reached in the Final Environmental Impact Statement that operation of the facility will not result in a significant dose commitment to the Maximum Exposed Individual.

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CONTENTS A B ST RA C T ................................................................................................................................. 2 SUM MAA R Y ................................................................................................................................. 3 IN T ROD U C T IO N ....................................................................................................................... 5 PROGRAM DESCRIPTION .................................................................................................. 5 RE SU L TS ..................................................................................................................................... 6 DIS C U SSION .................................................................. ......................................................... 8 CONCLUSION ........ ......

................. ..........................................8 REFERENCES "............................... .. 9 FIGURES

1. TM I-2 ISFSI TLD Station Locations ...................................................................... ........... 6 TABLES

1. TMI-2 ISFSI Air Sample Results (pCi/r).... ................................................ 7

2. TMI-2 ISFSI TLD Results (mre ...................

./d) .................. 7 4

Annual Radiological Environmental Monitoring Program Report for the Three Mile Island, Unit 2, Independent Spent Fuel Storage Installation INTRODUCTION Tile Three Mile Island, Unit 2, Independent Spent Fuel Storage Installation (TMI-2 ISFSJ) is a spent 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 National Laboratory (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 to 10 CFR 72 for authorization to receive, possess, store, and transfer spent fuel and fuel debris, resulting firom 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 up to twelve TMI-2 stainless steel canisters inside a dry shielded canister (DSC) which is placed inside a concrete horizontal storage module (HSMI). The NUHOMS-12T mnodification includes venting of the DSC through high efficiency particulate air (H-EPA) grade filters during storage. The vent system allows for release of hydrogen gas, generated due to radiolysis, and monitoring and/or purging of the system during operation.

The TMI-2 core debris which had been stored in stainless steel canisters in a fuel pool at the Test Area North (TAN) site within the INL has been transferred to the TMI-2 ISFSI for interim storage. A Settlement Agreement entered into by the State of Idaho, the Department of Energy, and the Department of 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 on March 31, 1999. Nine additional transfers were completedduring 2000. The remaining nineteen transfers 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 ISFSI and implemented in accordance with 10 CF.R 72.44. This report presents the REMD.results during the TMI-2 ISFSI operation in 2014.

PROGRAM DESCRIPTION The REMP is designed to monitor the two predominant radiation exposure pathways inherent with the facility design: potential airborne radioactivity releases and direct radiation. The airborne radioactivity release pathway is monitored using a combinationofloose surface radioactive contamination surveys and periodic airborne radioactivity sampling. The direct radiation exposure pathway is monitored using thermoluminescent dosimetry (TLD) located along the outer perimeter fence of the TMI-2 ISFSI.

Loose surface radioactive contain inationsunrveys are performed at the vent and purge ports of each DSC as well as the drain port of each loaded HSSM. The survey frequency was monthly during the first year, quarterly during the second through fifth years, and is now annually. The frequency coincides with the radiation monitoring surveil lance schedule required by the TMI-2 ISFSI Technical 5

Specifications.". Sample media is analyzed for beta..radioadtivity. Depending on the amount.of beta radioactivity detected, gamma isotopic analysis is either performed for each sample or for an annual sample 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 quarterly frequency. The minimum detectable dose is no greater than 10 mremn. Since the TMI-2 ISFSI is located among other non-licensed DOE nuclear facilities, there is no specific control TLD station for the TMI-2 ISFSI. 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 47 N

61 30.29 28271 26'125T2414234221120 Ai16

[1.17 60 *. Location TLD U. " ,A-ir Samtpler

'49' flj 94ý 13[12111109 8.17] ilK!_31 11 50 58 57. 56 5 .54 .53 .52 .51 A Iow-volumeair sampler is used to collect air through a particulate filter during a seven-day period 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) no greater than 0.01 pCi/m3 . Depending on the amount of beta radioactivity detected, gamma isotopic analysis is either performed for each air particulate sample or for an annual sample composite. The presence of Cs-137 is qualitatively determinied (or quantitativ'ely. as necessary) during the gamma isotopic analysis. Independent airborne radioactivity monitoring stations are maintained off-site of the INL by the INL Environmental Surveillance Program (one station in .Howe, ID), the Idaho Department of Environmental Quality INL Oversight Program :(three distance stations at Crater of the Moon National Monument, Fort Hall, ID and Idaho Falls, ID), and the Environmental Protection Agency, Region 10 (one station in Boise, ID). These stationsare relied upon.as control air sampling stations; the sampling results of which are used for comparison purposes..

RESULTS The loose surface contamination survey resu Its for the'purge, vent, and drain ports were less than the Minimum Detectable Activity (MDA), 32 dpm/1 00 cm 2 beta/gamma and 19 dpm/100 cm2 alpha, 6.

calculated in accordance with NUREG/CR-1 507,2. The gamma isotopic -results for the purge, vent, and drain port contamination survey composite samples from the HSMs indicated no fission product radioactivity. Cs-137 radioactivity was less than MDA which averaged 1.5E-2 nCi/sample; wellibelow the 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/rn 3) on each monthly sample collected during Januaty and March tihrough December. Beta radioactivity for the sample collected in February was detected above the established threshold at 6.1 E- 14 ltCi/cc. Gamma spectroscopy results of the colnposited air samples collectedlthroughout the year did not indicate the presence 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' 0.02 Februaiw, 0.06 .. August 0.02 March 0.01 September 0.02 April 0.02 October 0.02 MNlay 0.01 November 0.04

.lune 0.02 December 0.03 TLD results are presented in Table 2 in units of mrem/d. TLD results include an artificial phantom backscatter correction of 3% to expressthe results in dose equivalent units.. Quarterly standard deviations were between 0.1 rnrem/d and 0.2 mtem/d. Analysis of variance results indicated that during the 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 indicated quarterly mean TLD responses were in all cases significantly lower than the pre-operational baseline mean measured in March 1999 due to introduction of a new environmental dosimeter and processing system in June 1999.6 Mean TLD responses ranged from 0.5 to 0.9 mrem/d. Radiation monitoring at other locations within the 100 meter perimeter was not performed due to extremely low building occupancy 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 MEAN 40 0.7 0.6 0.6 0.6 0.6 41 0.6 0.6 0.6 0.6 0.6 42 0.6 0.5 0.5 0.5 0.6 43 0.6 0.5 0.5 0.5 0.6 44 0.6 0.5 0.5 0.5 0.5 45 0.6 0.5- 0.5 0.5 0.5 46 0.6. 0.5 0.5 0.5 *0.5 47 0.6 0.5 0.5 0.5 0.5 48 0.6 0.5 0.5 0.5 0.5 49 0.6 0.6 0.5 0.6 0.6 50 0.6 0.6 0.6 0.6 0.6 5.1 0.8 0.7 0.6 0.7 0.7 52 0.8 0.7 0.6 0.7 0.7 53 0.8 0.7 0.7 0.8 0.8 54 0.8 0.8 0.7 0.8 0.8 7

Table 2. TMI-2 ISFSI TLD Results (mrern/d) (continued)..

LOCATION QI Q2 Q3 Q4 MEAN 55 0.8 0.8 0.7 0.8 0.8 56 0.9 0.8 "  :.0.8 .0.9 0.8

.57 0.9 0.8 0.8 0.9 *0.9

58. 0.9 0.8 0.8 0.9 0.9 59 0. 0.8 *0.8 0.9' :0.8 60 0.8 .- 0.7' 0.7 0.8 0.7 61 0.7 0.7 0.7 0.8 0.7 MEAN 0.7 0.6 0.6 0.7 0.7 DISCUSSION The TMI-2 ISFSI REMP Was conducted in accordance with establishecl procedures. There wvere no changes made to the TMI-2 ISFS1 REMP during 2014.

The loose surface raclioactive contamination survey results indicate there has been no measurable release of raclioactive material from tile DSCs stored in the HSMs at the ISFSI above and beyond that projected in the Final Environmental Impact Statement (EIS). 7 Radioanalytical results are not significantly 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 of radioactive mateiial from the DSCs stored in the HSMs at the ISFSI above and beyond that projected in the EIS.

The radiation dosimetry results indicate there has been no measurable increase in ambient background radiation levels outside the TMI-2 ISFSI perimeter fence attributed to storage of the TMI-2 core debris. The absence of any significant increase in radiation levels outside the TMI-2 ISFSI perimeter fence also supports conclusions reached in the EIS.

Calibration and quality control of instrumentation used for beta analysis of surface contamination and airborne radioactivity sample media is maintained in accordance with procedLures used by the Idaho Cleanup Project (ICP) Radiological Control Program.8 Radioactivity sources used for instrumentation calibration and quality control are traceable to the National Institute of Standards and Technology (NIST).

CONCLUSION Airborne radioactivity releases and direct radiation exposure from the facility during 2014 did not contribute 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 no radioactive liquid effluents released from the facility, hence no radionuclides to report.

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REFERENCES

1. Materials License SNM-2508 for the Three Mile Island, Unit 2, Independent Spent Fuel Storage Installation (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 and High-Level Radioactive Waste," Code of FederalRegulations, Office of the Federal Register, October 2004.

3. Settlement Agreement between the State of Idaho, Department of the Navy, and the Department of Energy, October 16, 1995.

4. Technical Specifications and Bases for the INL TMI-2 Independent Spent Fuel Storage Installation.

5. NUREG/CR-1507, "Minimuml Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions," December 1997.

6. P. E. Ruhter, N"ewl EnvironmentalDosimeterResponse, letter PER-i17-99, July 29, 1999.

7. NUREG-1626, "Final Environmental Impact Statement for the Construction and Operation of an Independent Spent Fuel Storage Installation to Store the Three Mile Island Unit 2 Spent Fuel at the Idaho National Engineering and Environmental Laboratory," Docket No. 72-20, March 1998.

8. ICP, Radiological Control M*ntals 15B and 15C.

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