ML22027A681
| ML22027A681 | |
| Person / Time | |
|---|---|
| Issue date: | 01/18/2022 |
| From: | NRC Region 1 |
| To: | |
| Sheehan N | |
| References | |
| Download: ML22027A681 (27) | |
Text
Overview of Pilgrim Liquid Discharge Considerations Briefing for NDCAP Vice-Chair U.S. NRC Region 1 18 JAN 2022
Agenda
- 1. Review of Regulatory Approach to Effluents
- 2. History of Effluent Releases at Pilgrim
- 3. History of Environmental Monitoring Near Pilgrim
- 4. Tritium in Perspective
- 5. Regulatory Summary
- 6. YOUR questions 2
- 1. The Regulatory Approach
- 10 CFR 20 (U.S. NRC)
- 40 CFR 190 (U.S. EPA)
- NPDES Permit (State of Massachusetts and EPA) 3
Regulations - NRC
- Radiation Safety Regulations Apply to ALL Licensees (medical, manufacturing, power, etc)
- Objectives Based
- Performance Objectives vs Specific Criteria
- What vs How
- NRC compared to OSHA
- Radiation Dose Based
- Absorbed dose is the best indicator of potential health risks
- Regulatory Limits Are Not Safety Limits (10 CFR 20)
- Conservative Assumptions in Guidance Documents 4
NRC - 10 CFR 20 5
NRC - 10 CFR 20 6
Another Option Available NRC - 10 CFR 20 7
EPA - 40 CFR 190 8
EPA - 40 CFR 190 H-3 (Tritium) not listed 9
Existing NPDES Permit 10
- 2. History of Effluent Releases Publicly available at: https://www.nrc.gov/reactors/operating/ops-experience/tritium/plant-info.html 11
Number of Liquid Releases & Volume - Pilgrim Station 35 350000 30 29 300000 Volume (gallons)
No. Releases 25 250000 21 20 200000 Number of liquid releases 15 150000 10 100000 7
6 5
5 4 50000 3
2 2 1 1 0 0 0 0 0 0 0 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Year 12
Comparison of Annual Tritium Releases, Gas & Liquid - Pilgrim 500 Liquid Releases Gas Releases 450 400 350 300 250 200 Note: values in the blue call-outs show the activity of Tritium in the liquid release, in Curies Tritium Activity Released (Curies) 150 0 0.141 0.23 0 1.98 2.48 4.43 0.099 6.2 0.0039 3.56 0.0015 0.00082 0 0 0 100 50 0
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Year 13
Comparison of Liquid and Gas Releases to Limits - Pilgrim 120 NRC annual whole-body dose limit as found in 10 CFR 20.1301 100 Typical whole-body dose from one transcontinential flight in the summer season (4 millirem) 80 60 Note: values in the blue call-outs show the TOTAL whole-body dose for ALL radionuclides and ALL releases in that year 40 Dose from ALL Radionuclides in millirem EPA annual whole-body dose limit as found in 40 CFR 190 20 3.00 0.57 0.05 0.08 0.03 0.02 0.02 0.01 0.90 0.10 0.12 0.03 0.05 0.02 0.05 0.00 0
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Year Liquid Releases Gas Releases 14
Dose Calculations - Assumptions and Example Fish: 21 kg/yr Shellfish: 9 kg/yr Swimming: 52 hrs/yr Boating: 52 hrs/yr 15
Groundwater - 2020 Annual Report EPA Drinking Water Standard:
- Assumes that all drinking water in a year contains tritium at this level
- Is assumed to equal 4 mrem/yr (not correct and a significant over-estimate) 16
- 3. History of Environmental Monitoring Publicly available at: https://www.nrc.gov/reactors/operating/ops-experience/tritium/plant-info.html 17
Radiological Environmental Monitoring Program
- Required as part of the facilitys licensing basis
- Results reported annually
- Described in Regulatory Guide 04-001
- Objectives
- Evaluate the local environment to establish a baseline prior to operation
- Determine if any measurable radiation or radioactive materials are attributable to plant operation
- Determine if any measurable radiation or radioactive materials that are attributable to plant operation are commensurate with the reported effluents and meet design objectives 18
Samples and Monitoring 19
Sampling Results - Aquatic Edibles 2020
- Shellfish:
- Blue mussels and soft-shelled clams
- Natural K-40 detected, as expected
- No plant-related radionuclides, results similar to pre-operational period
- Lobster:
- Collected from outfall June, July, August, September
- Results same as shellfish
- Fish:
- Some species harder to collect as warm discharge water has stopped
- Results same a shellfish 20
Sample Results - Surface Water 2020 Sample Point Release Point Note: No H-3 (tritium) was detected in 2011, the year with the largest number of liquid releases 21
- 4. Tritium in Perspective
- A radioactive isotope of Hydrogen (one proton, two neutrons)
- Produced naturally in the upper atmosphere when cosmic rays interact with Nitrogen atoms (along with C-14 and Be-7)
- Produced by reactors, however releases are at fractions of the natural background production rate [EPA fact sheet]
- Can be found at very low concentrations in lakes and streams (about 4 pCi/L)
- Radiation emitted as Beta particles of very low energy (cannot penetrate the skin surface)
- Rapidly incorporates with water molecules and cannot be removed
- Because water turns over rapidly in the body, tritium in the body is rapidly cleared from tissues [EPA fact sheet, 10-day biological half-life]
22
Relative Risks - Tritium
- Dose per unit of radioactivity in the body - ingestion
- K-40: 5.02 E-09
- Cs-137: 1.35E-08
- Co-60: 7.28 E-09
- Ra-226: 6.83 E-06 [Bone Surface]
- Th-232: 1.85 E-05 [Bone Surface]
Comparison of Tritium Risk to Other Radionuclides 80,000 70,000 68,450.0 60,000 50,000 40,000 30,000 25,271.0 Relative Risk (millirem per microCurie ingested) 20,000 10,000 0.1 18.6 50.0 26.9 0
H-3 K-40 Cs-137 Co-60 Ra-226 Th-232 Radionuclide 24
- Popular shopping site
- Tritium activity not even listed
- Found online
- No warning or precautions
- Each watch contains 27,000 microCuries of H-3 25
- 5. Regulatory Summary
- Anthony Dimitradis, Branch Chief Region 1 26
27 This Photo by Unknown Author is licensed under CC BY-NC