ML060960149

G20060270 - James E. Zelko Ltr Re. Braidwood - Handling and Storage of Tritiated Water

ML060960149
Person / Time
Site:	Braidwood
Issue date:	04/24/2006
From:	Dyer J Office of Nuclear Reactor Regulation
To:	Zelko J Will County, IL, Health Department and Community Health Ctr
Kuntz, Robert F, NRR/DORL, 415-3733
Shared Package
ML060960159	List: ML060810501 ML060960149 ML061080228
References
G20060270, TAC MD0688, TAC MD0689
Download: ML060960149 (5)

Text

April 24, 2006Mr. James E. ZelkoExecutive Director Will County Health Department & Community Health Center 501 Ella Avenue Joliet, IL 60433

Dear Mr. Zelko:

I am responding to your letter of March 15, 2006, seeking information related to eventsinvolving the handling and storage of tritiated water at Exelon Generation Company, LLC's (Exelon's) Braidwood Station. The Nuclear Regulatory Commission (NRC) shares yourconcerns regarding these issues at Braidwood. Although Exelon has recently identified the migration of tritiated water to offsite locations, our current assessment does not indicate any hazard to the public or to the environment. However, we are concerned that radioactive material was released in a manner that was not intended. In your letter, you expressed a concern that tritium is potentially linked to excess cancermortality. The NRC staff shares your concern with potential effects of radioactive material on the health and safety of the public. As with all ionizing radiation, the NRC assumes as aprudent precaution for the purposes of radiation protection that the risk of developing cancerfrom tritium exposure increases as exposure increases. That is why the NRC has set strict limits on the amount of radiation that the general public can be exposed to from nuclear powerplant operations. Our assessment indicates that the migration of tritium off-site at Braidwoodremains well below our dose limits.The NRC takes very seriously its mission to protect the public's health and safety from radioactive effluent discharges from nuclear power plants. I would like to briefly summarize our regulatory requirements to describe our regulatory framework and inspection process in place to routinely review radiological effluents. I will also address the information you requested onExelon's handling, storage, disposal plans, sampling methodology, and the NRC's plans relatedto Braidwood tritium issues.1.NRC Regulatory Framework for Radiological EffluentsThe most notable NRC regulations in place to ensure that licensees maintain adequate controlover radioactive effluents are Title 10 of the Code of Federal Regulations (CFR), "Standards forProtection Against Radiation," and 10 CFR Part 50, Appendix I, "Numerical Guides for Design Objectives and Limiting Conditions for Operation to Meet the Criterion "As Low As Is Reasonably Achievable" for Radioactive Material in Light-Water-Cooled Nuclear Power Reactor Effluents." These regulations establish requirements for the control of radioactive material to limit radiation exposure to workers and members of the public and the impact on the environment. These regulations require the licensee to maintain exposures as low as is reasonably achievable. Nuclear power reactors are required to maintain radioactive effluent releases to levels that will not cause the annual dose to a member of the public to exceed 1000 µSv (100 mrem). The design objective is 30

µSv (3 mrem) from liquid releases.

J. Zelko- 2 -The regulations also require licensees to operate monitoring programs to assess release levels,and potential doses to people who may be exposed.Section IV.B of Appendix I to 10 CFR Part 50 states:The licensee shall establish an appropriate surveillance and monitoring programto: 1. Provide data on quantities of radioactive material released in liquid and gaseous effluents... 2. Provide data on measurable levels of radiation and radioactive materials in the environment to evaluate the relationship between quantities of radioactive material released in effluents and resultant radiation doses to individuals from principal pathways of exposure; and, 3. Identify changes in the use of unrestricted areas (e.g., for agricultural purposes) to permit modifications in monitoring programs for evaluating doses to individuals from principal pathways of exposure.Radiological environmental monitoring and effluent monitoring at nuclear power plants arerequired by the NRC regulations contained in General Design Criteria 60, 61, and 64 ofAppendix A to Title 10 of the Code of Federal Regulations (10 CFR) Part 50. Such monitoringis important for plant operations. During operations, environmental monitoring verifies the effectiveness of in-plant measures for controlling the release of radioactive materials, and ensures that the levels of radioactive materials in the environment do not exceed the levelsanticipated before the plant was licensed.Licensees are also required to submit to the NRC (1) annual radiological environmental andeffluent monitoring reports on radiological effluent releases from the plant and their impact on the environment, and (2) a special report within 30 days of discovery of an event if predetermined levels of radioactivity are exceeded. In addition, the NRC requires that thelicensee participate in an Interlaboratory Comparison Program to ensure the accuracy of the licensee's data. The results of the licensee's radiological environmental monitoring and effluent release programs are available to the public.2.NRC Response to Recent Concerns about Environmental ContaminationIn response to recent concerns about environmental contamination at nuclear power plant sites,the NRC has assessed the significance of this contamination and confirmed adequateprotection of the public. This has included additional inspections at the sites, including observation of licensee monitoring and collection of independent samples to conform the representation and accuracy of licensee samples. The NRC has also participated in public foraand increased stakeholder outreach to explain our regulatory program and answer questions and hear comments. In addition, the NRC has added a page on the NRC Web site to give thepublic the latest available information on tritium issues. This information can be accessed by going to www.NRC.gov, then using the link "Groundwater Contamination (Tritium)." We areconsidering whether additional actions are necessary as part of our ongoing over site of licensee performance.

J. Zelko- 3 -As a separate complimentary action, the NRC has formed a task force to examine the agency'sregulations for radiological effluent and environmental monitoring programs and the associated inspection program. The task force is addressing several topics, including:*A general assessment of the potential public health impact from inadvertantreleases*How the issues were communicated to the public, State and local officials, otherFederal agencies, Congress, and other interested groups*A review of other inadvertent releases at nuclear power plants, includingdecommissioning sites, from 1996 to the present*Industry actions in response to the releases, including the timing of remediationefforts*NRC oversight of inadvertent releases, both under the Reactor OversightProcess (ROP) and the process in place prior to the ROPThe task force will be completing its review by August 31, 2006. A written report summarizingthe task force's findings will be issued late this year. The task force's charter is available on theNRC's Web site by going to www.NRC.gov, then using the link to "Groundwater Contamination(Tritium)," and then "NRC Actions." On February 7, 2006, Exelon made a written commitment (Agencywide Documents Access andManagement System (ADAMS) ML060670040) to the NRC to suspend liquid effluent releasesthrough the blowdown line. Exelon also committed to communicate with the NRC before anyfuture radioactive releases through the blowdown line and before disposition of the stored liquids onsite by any method other than recycling back into the plant. The NRC confirmedthese commitments in a letter dated February 17, 2006 (ADAMS ML060660590). In addition, to ensure that the licensee operates in a manner that continues to ensure the protection of thepublic and in accordance with Federal regulations and the plant's license, the NRC continuouslyassesses the licensee's performance in accordance with the NRC oversight process. As part of the NRC's oversight process, inspectors evaluate the licensee's performance thr oughinspection. Specifically, for the issues related to tritium at Braidwood, the inspectors initially used Inspection Procedure 71153, "Event Followup." After gaining a preliminary understanding of the situation, the inspectors utilized other inspection procedures such as InspectionProcedures 71122.01, "Radioactive Gaseous and Liquid Effluent Treatment and Monitoring Systems," and 71122.03, "Radiological Environmental Monitoring Program (REMP) and Radioactive Material Control Program." These procedures are available on the NRC's publicWeb site at www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html

.The NRC will continue to verify the licensee's activities related to the blowdown line byinspecting the adequacy of Exelon's ability to prevent, detect, respond to, and radiologicallyassess any leakage from the blowdown line.

J. Zelko- 4 -The results of the NRC inspection activities are documented in publically availableinspection reports. The initial inspection activities were documented in NRC InspectionReports 05000456/20050010 and 05000457/20050010, issued on February 6, 2006.

The current inspection activities will be documented in NRC Inspection Reports05000456/2006008 and 05000457/2006008. Issued inspection reports are available on the NRC's public Web site athttp://www.nrc.gov/NRR/OVERSIGHT/ASSESS/listofrpts_body.html#brai

.

3.Exelon's Handling of Tritium, Storage, and Disposal Plans at BraidwoodThe Braidwood Station discontinued the normal release of water containing tritium onNovember 23, 2005. Since that time the plant has installed temporary tanks to store the watercontaminated with tritium that normally would have been released to the Kankakee River.

These tanks are fixed-rear-axle container tanks used for storage only (they are not used for transport). Currently, there are 21 of these 21,000 gallon temporary storage tanks on the Braidwood site, and the licensee plans to add additional tanks as necessary. The temporary tanks are located in two areas within the plant's security fence. One of the areas is outdoorsand contains 14 tanks surrounded by a 12-inch-high berm wall. The other area is in an on site storage building which currently contains seven tanks that are surrounded by a similar berm.

The licensee may install additional tanks inside this building. The licensee is also making preparations to potentially utilize other permanent tanks available on site to store the water.Exelon is in the process of determining a permanent solution for tritium disposal, and is workingwith State agencies and the NRC. The options include, but are not limited to (1) recycling thetritiated water for nuclear plant makeup water, (2) recommencing liquid releases through the blowdown line (after upgrading the blowdown line and related equipment and installing leak-monitoring devices), and (3) evaporating the tritiated water. Any alternative selected by the licensee will have to meet NRC requirements in 10 CFR Part 20.NRC's resident and regional inspectors are performing an analysis of the storage tanks andassociated compensatory measures. The inspectors' review of the temporary storage tanks and compensatory measures found them to be in accordance with the licensee's Technical Requirements Manual and not to pose a threat to public health. Furthermore, the inspectors continue monitoring the licensee's handling of tritium.4.Groundwater Sampling and Results The Braidwood Station has installed monitoring wells both on site and off site. Sincediscovering the presence of tritium off site, Exelon has installed approximately 140 new wells and taken other water samples as follows:*Alongside the vaults of the vacuum breakers for the circulating water blowdownline*At sufficient locations to characterize and identify the perimeter of the tritiumplumes of past leaks*At shallow depths of approximately 13 feet

• At deeper depths of approximately 30 feet to determine levels in the shallow J. Zelko- 5 -aquifer and clay till level*At resident drinking wells in the vicinity of the plant and the blowdown line The NRC has collected independent samples and has obtained split samples from these wellsfor independent analysis of tritium levels. A split sample is a sample drawn by the licensee and a portion is provided to the NRC for independent analysis. To date, the NRC's analytical resultshave been consistent with the licensee's. The enclosure lists the sample results.

Also enclosed is a map showing the tritium plume that is 2,400 to 2,800 feet north of the plant'sproperty line.The NRC has also analyzed a number of samples for other radioactive material besides tritium, including gamma-emitting radioactivity, strontium-90, and technitium-99. Based on our own analysis, no licensed radioactive material other than tritium was identified above detection limits.5.Conclusion As I stated earlier, I share your concern about tritium contamination at Braidwood and othersites. In particular, I am concerned that the licensee may not have adequately identified the significance of these historical events when they occurred and evaluated the dose consequences and the impact to the environment caused by these spills. However, based oncurrently available information, we believe that the contamination at Braidwood does not poseany threat to public health and safety. In closing, I assure you that the NRC is and will continueto be a strong regulatory authority and will ensure that corrective actions for these issues areeffective.Sincerely,J. E. Dyer, Director /RA/Office of Nuclear Reactor Regulation

Enclosures:

1. Tritium Sample Results

2. NRC Groundwater Measurement Results J. Zelko- 5 -*At deeper depths of approximately 30 feet to determine levels in the shallowaquifer and clay till level*At resident drinking wells in the vicinity of the plant and the blowdown line The NRC has collected independent samples and has obtained split samples from these wellsfor independent analysis of tritium levels. A split sample is a sample drawn by the licensee and a portion is provided to the NRC for independent analysis. To date, the NRC's analytical resultshave been consistent with the licensee's. The enclosure lists the sample results.

Also enclosed is a map showing the tritium plume that is 2,400 to 2,800 feet north of the plant'sproperty line.The NRC has also analyzed a number of samples for other radioactive material besides tritium, including gamma-emitting radioactivity, strontium-90, and technitium-99. Based on our own analysis, no licensed radioactive material other than tritium was identified above detection limits.5.Conclusion As I stated earlier, I share your concern about tritium contamination at Braidwood and othersites. In particular, I am concerned that the licensee may not have adequately identified the significance of these historical events when they occurred and evaluated the dose consequences and the impact to the environment caused by these spills. However, based oncurrently available information, we believe that the contamination at Braidwood does not poseany threat to public health and safety. In closing, I assure you that the NRC is and will continueto be a strong regulatory authority and will ensure that corrective actions for these issues areeffective.Sincerely,J. E. Dyer, DirectorOffice of Nuclear Reactor Regulation

Enclosures:

1. Tritium Sample Results

2. NRC Groundwater Measurement ResultsDISTRIBUTION: G20060270 PublicRidsEdoMailCenterRidsNrrOdRidsNrrAdroRidsOgcRpRidsOpaMailRidsOcaMailCenterRidsNrrWpcMailRidsNrrDorl RidsNrrDorlLplIII-2RidsNrrPMMChawlaRidsNrrLADClarkeLPLIII-2 R/FRidsRgn3MailCenterRidsNmssOdOPATFryeSklementowiczvia email*Package: ML060960159Incoming: ML060810501Letter: ML060960149OFFICELPL3-1/PMLPL3-1/LADIRS/IHPB:BCLPL3-1/BC NAMEMChawla:caDClarkeTFryeDCollins DATE04/10/0604/19/0604/18/06 04 /19/06OFFICETech EditorRIII/DRSDORL/DNRR/DNAMEPKleeneABoland*CHaneyJDyer DATE04/10/0604/7/0604/19/0604/ 24/06OFFICIAL RECORD COPY Tritium Sample ResultsTritium concentrations are reported in the units of picocuries per liter. A picocuries is a verysmall amount of radioactivity equal to 0.000000000001 curie. As a result of natural and manmade causes, tritium is generally found in surface water in concentrations in the 200 to 300 pci/L range. Additional information useful in reading this table is found in the footnotes. Braidwood Tritium Sample ResultsNRC Split Sample ResultsLicenseeSample Designation 1Collection DatepCi/L 2pCi/L2,3NRCSample IDRatioLicensee to NRC 4P-112-01-0524842930NRC-1-R30.848P-412-01-053304133630NRC-2-R30.982P-512-01-0566216820NRC-3-R30.971P-612-01-05450190NRC-4-R3StatisticallyInsignificantP-712-01-0512101200NRC-5-R31.008P-812-01-0529982720NRC-6-R31.102RW-112-01-0520502650NRC-7-R30.774RW-212-01-053373634760NRC-8-R30.971BL-1712-01-0525240NRC-9-R3StatisticallyInsignificantBL-1812-01-05108150NRC-10-R3StatisticallyInsignificantBL-1912-01-0537300NRC-11-R3StatisticallyInsignificantPW-912-05-05142-340NRC-12-R3StatisticallyInsignificantPW-1112-05-0599100NRC-13-R3StatisticallyInsignificantPW-412-02-0543200NRC-14-R3StatisticallyInsignificantSW-412-02-0583210NRC-15-R3StatisticallyInsignificantPW-812-03-0511511490NRC-16-R30.772D-312-02-05137-60NRC-17-R3StatisticallyInsignificantRW-312-02-05197140NRC-18-R3StatisticallyInsignificantRW-412-02-05380420NRC-19-R30.905P-212-02-0543442750NRC-20-R31.580P-312-02-0532582470NRC-21-R31.319VB3-712-02-05169-90NRC-22-R3StatisticallyInsignificant Braidwood Tritium Sample ResultsNRC Split Sample ResultsLicenseeSample Designation 1Collection DatepCi/L 2pCi/L2,3NRCSample IDRatioLicensee to NRC 4VB3-812-02-05171110NRC-23-R3StatisticallyInsignificantPW-111-30-05-26200NRC-24-R3StatisticallyInsignificantPW-211-30-0548180NRC-25-R3StatisticallyInsignificantPW-311-30-0525-250NRC-26-R3StatisticallyInsignificantPW-812-06-0515241020NRC-27-R31.494SW-111-30-0524642480NRC-28-R30.994SW-211-30-0523472490NRC-29-R30.943G-112-06-05133290NRC-30-R3StatisticallyInsignificantG-212-06-0587230NRC-31-R3StatisticallyInsignificantG-312-06-0581140NRC-32-R3StatisticallyInsignificantP-912-05-051346-40NRC-33-R3StatisticallyInsignificantP-1012-05-0519342120NRC-34-R30.912P-1112-05-0516811770NRC-35-R30.950P-1212-05-0515351400NRC-36-R31.096S-112-05-05-21-70NRC-37-R3StatisticallyInsignificantS-212-05-0595110NRC-38-R3StatisticallyInsignificantS-312-05-05145140NRC-39-R3StatisticallyInsignificantS-412-05-0512801230NRC-40-R31.041S-512-05-0520232190NRC-41-R30.924S-612-05-05679490NRC-42-R31.386D-412-06-0591-30NRC-43-R3StatisticallyInsignificantD-212-05-05125-40NRC-44-R3StatisticallyInsignificantP-412-06-052531130020NRC-45-R30.843P-812-06-0522122500NRC-46-R30.885VB2-612-05-0523481640NRC-47-R3 1.432 Braidwood Tritium Sample ResultsNRC Split Sample ResultsLicenseeSample Designation 1Collection DatepCi/L 2pCi/L2,3NRCSample IDRatioLicensee to NRC 4VB3-412-05-054370842580NRC-48-R3 1.026MW-11312-05-0535983840NRC-49-R30.937NRC Sample(VB 3-4)11-30-0539400NRC-50-R3D-512-02-0573280NRC-51-R3StatisticallyInsignificantNRC Sample(PW-3)12-07-05280NRC-52-R3NRC Sample(PW-2)12-08-05210NRC-53-R3NRC Sample(PW-1)12-08-05150NRC-54-R3PW-512-07-059310NRC-55-R3StatisticallyInsignificantPW-1012-07-0572210NRC-56-R3StatisticallyInsignificantPW-1212-07-0544190NRC-57-R3StatisticallyInsignificantPW-712-07-05-58170NRC-58-R3StatisticallyInsignificantVB3-9D12-13-052171521720NRC-61-R31.000MW-113D12-14-0548354810NRC-62-R31.005P-2D12-12-0525992480NRC-63-R31.048RW-2@10'12-13-055411155920NRC-64-R30.968RW-2@20'12-13-05171166160400NRC-65-R31.067RW-2@25'12-13-05246442281800NRC-66-R30.875NRC Sample(PW-8) 12-27-051310NRC-67-R3NRC Sample (SW)12-08-05-30NRC-68-R3NRC Sample 12-08-05 1360NRC-69-R3 1The Licensee Sample Designation code provides some indication of the location:BLBlowdown LinePWPrivate Well Dnear the on-site DitchRWRemediation Well GPrivate WellSPrivate Well MWMonitoring WellSWSurface Water PPondVBVacuum Breaker 2The negative numbers indicated radioactivity statistically indistinguishable from backgroundradiation or from the laboratory's Lower Limit of Detection (LLD). 3The NRC's contract laboratory's LLDs:(1)drinking water wells 200 picocuries per liter (2)non-drinking water wells 500 picocuries per liter 4The term Statistically Insignificant applied when sample results are near the LLD.