ML061170621

NRC SIT Slides for the Public Meeting Regarding Contamination of Onsite Groundwater

ML061170621
Person / Time
Site:	Indian Point
Issue date:	03/28/2006
From:	NRC Region 1
To:
References
Download: ML061170621 (12)

Text

NRC Special Inspection Indian Point Energy Center September 20, 2005 - February 28, 2006 Contamination of Onsite Groundwater Nuclear Regulatory Commission - Region I Public Meeting, Peekskill, New York March 28, 2006

2 Agenda

• Overview of Special Inspection

• Discussion of Dose and Dose Limits

• NRC Communications

3 NRC Overview

• Discovery and Initiation of Special Inspection

• Special Inspection Charter and Revision

• Scope of Special Inspection

• Results

• Next Steps

4 Discovery and Initiation of Special Inspection

• August 22, 2005 - Moist SFP crack first identified, nothing detectable

• September 1, 2005 - Contamination detected on swipe sample-NRC informed

• September 7-15, 2005 - NRC preliminary structural and radiological assessments performed

• September 12, 2005 - First liquid volume collected for analysis

• September 19, 2005 - Tritium detected from SFP crack leakage similar to SFP

• September 20, 2005 - Special Inspection Charter issued

• October 5, 2005 - Tritium contamination found in an onsite monitoring well (MW-111)

• October 7, 2005 - Special Inspection Charter revised

Special Inspection Charter and 5 Revision

• Determine the facts and assess the conditions of the Unit 2 spent fuel pool leak

• Areas of Review: spent fuel pool structural strength, radiological sampling and dose impact assessment, and adequacy of Entergys corrective actions

• Charter was revised to include investigation of groundwater contamination in the Unit 2 transformer yard (MW-111) and monitoring/control of the Unit 1 SFP leakage

6 Scope of Special Inspection

• Unit 2 spent fuel pool structural integrity

• Unit 2 spent fuel pool liner inspection for leaks

• Radiological assessment of bounding dose calculation

• Independent sampling of both onsite groundwater and offsite water locations

• Site groundwater transport characterization

• Previous samples and data reviewed for possible precursor conditions

• Unit 1 spent fuel pool leakage collection efficiency

7 Inspection Results

• No issues relative to Unit 2 spent fuel pool structural integrity

• Approximately 40% of pool liner inspected - no leaks identified, more to follow

• Bounding dose calculations continue to indicate that regulatory dose limits are being met

• The most recent estimated dose was approximately 0.1% of regulatory limits

• 3-way sample splits between New York State, the NRC, and Entergy confirmed no plant-related activity detected at offsite environmental sampling locations

8 Inspection Results (Cont.)

• Site groundwater characterization efforts are technically sound and provide useful information

• To date, no circumstances identified that reasonably should have led Entergy to earlier detection or prevention of current onsite conditions

• Unit 1 spent fuel pool drain system performance and efficiency are not completely understood. Continued efforts are necessary to assure that all leakage is accounted for and effectively handled

• The cause of the onsite conditions and corrective actions are being pursued in a reasonable manner. Efforts to determine source(s) of contamination and effect mitigation or remediation are progressing.

9 Next Steps

• Continue to assess Entergys performance, effectiveness, and diligence relative to resolving the source and extent of this groundwater contamination

• Recognizing the evolving nature of this investigation, take appropriate regulatory actions as warranted by inspection findings

• Continually assess dose consequence, regulatory compliance and impact to public health and safety

• Evaluate onsite and offsite groundwater monitoring plans to assure early detection of contamination

10 Summary Of Current NRC Assessment

• Based on current information, public health and safety has not been, nor is likely to be, adversely affected.

• The source(s) causing ground water contamination have not been positively identified.

• The NRC will continue regulatory oversight of Entergys efforts and activities to resolve the condition. A follow-up NRC inspection report will provide final conclusions.

• Since discovery, Entergys response has been reasonable and technically sound.

• NRC is reviewing generic implications of groundwater contamination.

11 Radiation Dose Perspective

• Background (est.) 360 mrem/year (NCRP 94)

• Public Dose Limits 100 mrem/year (10CFR20.1301) 25 mrem/year (40CFR190)

• Liquid Effluent Limit 3 mrem/year, total body 10 mrem/year, organ (10CFR50, App. I)

• Estimated Dose Rate 0.0034 mrem/year, total body 0.01 mrem/year, bone

• EPA drinking water limits (40 CFR 141.16)

Tritium (H-3) 20,000 pCi/L Strontium (Sr- 90) 8 pCi/L (EPA maximum contaminant level based on 4 mrems per year)

NRC Communications 12

• Lessons learned

• Corrective actions

• Communication efforts going forward