Radiological Environmental and Public Exposure Considerations for Existing and Future Nuclear Power Plants

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1 Radiological Environmental and Public Exposure Considerations for Existing and Future Nuclear Power Plants Jason T. Harris, Ph.D. Department of Physics and Nuclear Engineering Idaho State University David W. Miller, Ph.D. Department of Nuclear, Plasma, and Radiological Engineering University of Illinois at Urbana-Champaign

2 Introduction Commercial Nuclear Power Plants (NPPs) produce gaseous, liquid, and solid wastes during normal operations as a result of the beneficial electricity produced Radioactive waste treatment systems are used by these plants to assure radioactivity levels are ALARA (As Low As Reasonably Achievable) and below the limits required by governmental regulations Although the radioactivity levels released by NPPs can be quite low (effluents), they can still have environmental impacts on man, fauna, and flora Figure 1: U.S. Commercial Nuclear Power Plant Map 2

3 Possible New Plants According to recent MIT study, the two most important factors for new construction are financing and environmental siting

4 Public Exposure Although effluent releases are well below regulatory limits (1%) it is important to continually monitor and scrutinize effluent release programs Effluent releases have a direct financial impact on nuclear liability insurance premiums via the ERF (Engineering rating Factor) program. There is also an indirect financial impact. Performance information also plays an important part in the development of insurance risk profiles that support loss control strategies at each nuclear power plant facility. As technology improves, MDAs will decrease and what may not have been there in the past, may now appear Increased environmental findings at several operating and decommissioned plants Study effects of re-licensing, power uprates and new construction Multi-reactor sites concerns (C-14) Public perception and confidence (Reputation!) 4

5 REMP REMP NPPs required to monitor the radiological impact of reactor operations on the environment and public (NEPA 1969 and FWPCA 1976) implemented as RETS/ODCM (operational plants) Program Preoperational and operational components Trend and assess radiation exposure rates and conc. in the environment Annual report submitted (and for releases) Problem decreased programs, decreased LLDs (positive results), HTD, public opinion, recent unexpected releases, and staff turnover 5

6 REMP Objectives Validate Adequacy of Effluent Controls to Minimize Effluent Releases ALARA Systematic Approach to Monitor Major Pathways demonstrate no significant impact Primary Concern for Human Pathways Secondary Concern for Assessing Dose to non-human Organisms in the Environment Individual Licensees Commitments Vary Dated (based on 60 s technology changes coming)

7 NRC REMP Guidance Regulatory Guide 4.1, Programs for Monitoring Radioactivity in the Environs of Nuclear Power Plants (1975) Revision issued in 2009, new construction? Regulatory Guide 4.8, Environmental Technical Specifications for Nuclear Power Plants (1975) NUREG-0475, Radiological Environmental Monitoring by NRC Licensees for Routine Operations of Nuclear Facilities (1978) Branch Technical Position on Environmental Monitoring (1979) NUREG-1301/1302 (1991)

8 RG 1.21 NRC Reg. Guide Updates Release Points (and sample frequency) Principal Radionuclides (and LLD) C-14 Leaks and Spills Dose Assessments ARERR RG 4.1 REMP Exposure Pathways AREOR

9 Required Analyses & Sensitivity Nuclides Dependent on Media/Pathway Liquids vs. Solids, Foodstuffs vs. Basal Media (soil, sediment) Detection Sensitivity Dependent on Nuclide Lower Limit of Detection (LLD) Methodology Specified by NRC for Consistency (Major gamma emitters: pci/kg in solids) Originally based on [then] state of the art detection sensitivity, rather than dose impact Currently doesn t require LLDs for hard-to-detect nuclides in REMP samples Primarily C-14, Fe-55, Ni-63, Sr-89/90 others? Some foreign plants do monitor for HTD in REMP Results in gaps when applying REMP LLDs to other situations material release, groundwater monitoring, etc.

10 Environmental LLDs Additional Applications NRC defaulted to environmental LLDs as basis for unconditional free-release of bulk materials Reasonable survey within capabilities of licensee Clean = No Detectable Activity no acceptable level below regulatory concern Comparability/conflict with more recent MARSSIM freerelease criteria; REMP LLDs based on 1960s technology and guidance

11 Unconditional Release MARSSIM - Multi-Agency Radiation Survey and Site Investigation Manual Recent development -- Late 1990s Standardized approach agreed upon by multiple regulatory agencies (NRC, Department of Energy, Department of Defense, Environmental Protection Agency) Risk-based approach based on dose impact MARSSIM specifies acceptable levels of contamination suitable for free-release of site or material

12 Public Confidence Problems Groundwater Contamination Events Oyster Creek Indian Point Braidwood Callaway Dresden Byron Palo Verde Quad Cities 12

13 Groundwater Protection Initiative Tritium identified in groundwater at several sites in timeframe Led to voluntary industry initiative to institute groundwater monitoring at all commercial sites, coordinated through NEI and later EPRI REMP LLDs have been commonly accepted as de facto LLDs for groundwater analyses Many sites have incorporated groundwater monitoring as part of their REMP, especially for offsite wells

14 Basic Steps for GW Monitoring 14

15 Protection of Non-human Biota Protection of non-human species from radiation effects is element of many European programs Canadian Environmental Protection Act of 1999 recognized the need to assess impact on non-human biota. In 2003, ICRP issued ICRP-91, A framework for assessing the impact of ionising radiation on non-human species to provide guidance; ICRP Committee 5 activities IAEA activities in the Biota Working Group and Coordination Group on Radiation Protection of the Environment

16 Protection of Non-human Biota (cont.) US DOE includes non-human biota when assessing dose impact at their facilities; formed Biota Dose Assessment Committee in 1998; website: DOE-STD , A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota Much of the existing guidance appears intended for assessment of residual activity following decommissioning, as opposed to realtime effluent releases The NRC is considering establishment of guidance regarding assessment of impact to non-human biota for new construction; questions regarding applicability to currently operating plants

17 EPRI Actions Groundwater Protection Evaluation of systems, structures, components, and work practices Site hydrology Groundwater monitoring Grade Approach Remediation Monitored Natural Attenuation Tritium Atmospheric deposition In plant tritium and water management Precipitation washout 17

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19 NEI Actions Groundwater Protection Initiative NPP Issues Indian Point, Braidwood NRC Liquid Radioactive Release Lesson Learned Task Force NEI Technical Report (new plants) Meet operational requirements of 10 CFR & Reg. Guide 4.21 Minimize facility contamination Minimize environmental contamination Minimize generation of waste Facilitation of decommissioning Decommissioning Planning Rules 19

20 ISFSI Direct radiation gamma exposure rates from plant ISFSIs 20

21 Conclusions Future (and current) radiological environmental concerns RETS unplanned releases (tritium, groundwater) REMP HTDs, principle radionuclides, new pathways C-14 Decommissioning Non-human biota Implementation of new regulations 21

22 Acknowledgements Richard Conatser, U.S. NRC Ken Sejkora, Entergy Nuclear Northeast Pilgrim Station Karen Kim, EPRI 22

23 Questions? Thank You!