ML24198A170
| ML24198A170 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/09/2024 |
| From: | Flynn J - No Known Affiliation |
| To: | Office of Administration |
| References | |
| NRC-2024-0076, 89FR53659 00006 | |
| Download: ML24198A170 (1) | |
Text
PUBLIC SUBMISSION As of: 7/16/24, 12:47 PM Received: July 09, 2024 Status: Pending_Post Tracking No. lye-nc1a-vqsq Comments Due: July 29, 2024 Submission Type: Web Docket: NRC-2024-0076 Notice of Intent to Conduct Scoping Process and Prepare an Environmental Assessment Holtec Decommissioning International, LLC and Holtec Palisades, LLC; Palisades Nuclear Plant, Unit 1 Comment On: NRC-2024-0076-0001 Holtec Decommissioning International, LLC, and Holtec Palisades, LLC; Palisades Nuclear Plant; Notice of Intent To Conduct Scoping Process and Prepare an Environmental Assessment Document: NRC-2024-0076-DRAFT-0006 Comment on FR Doc # 2024-14112 Submitter Information Name: jody flynn Address:
covert, MI, 09043 Email:jodygflynn@gmail.com Phone:3175060803 General Comment It is critical that the GAOs report on the nuclear industries preparedness for climate change be analyzed and addressed in writing point by point so that the public is comfortable that the nuclear waste on the shores of Lake Michigan will be safe from all the unexpected storms, extreme temperatures, massive rains, droughts. This should be a priority.
Attachments REPORT. 2024. GAO. NRC failure address climate risks. (GAO) 7/16/24, 12:48 PM blob:https://www.fdms.gov/af933f57-b6c4-48ac-af84-a99d8ac0b70c blob:https://www.fdms.gov/af933f57-b6c4-48ac-af84-a99d8ac0b70c 1/1 SUNSI Review Complete Template=ADM-013 E-RIDS=ADM-03 ADD: Laura Willingham, Mary Richmond, Antoinette Walker-Smit, Jessica Hammock, Marlayna Doell, Mary Neely Comment (6)
Publication Date:6/27/2024 Citation: 89 FR 53659
1 April 2024 ~GAO - REPORT. 2024. GAO. NRC failure address climate risks. (GAO)
CIECP Synopsis last updated Apr 16, 2024 Council on Intelligent Energy & Conservation Policy (CIECP) SYNOPSIS GAO REPORT: Nuclear Power Plants:
NRC Should Take Actions to Fully Consider the Potential Effects of Climate Change (April 2024)
WIP - WORKING DRAFT.
KEY to this Document Box bracketed synopsis is not intended to be a comprehensive overview or summary. Words within curly brackets provide commentary or contextual information not within the underlying source. Some quoted passages omit spacing of original to save room.
We aim to be reliable but make no representations and urge others to double-check what is presented here. Internal footnote, cite, graph, and table references are, for the most part, excluded.
CIECP FOREWARD: This report synopsized is a Government Accountability Office (GAO) report to Congressional requesters. The requesters were Sen. Joe Manchin III, Chairman of the US Senate Committee on Energy and Natural Resources, and Sen. Tom Carper, Chairman of the Senate Committee on Environment and Public Works. GAO was asked to review the climate resilience of the US energy infrastructure. The GAOs focus in this report is exclusively on nuclear power plants. The central finding of the report is that climate change and natural hazard events pose risks to nuclear power plants which the Nuclear Regulatory Commission (NRC) is neither adequately analyzing nor addressing.
U.S. GAO: Rusco, Frank, Director, Natural Resources and Environment, U.S. Government Accountability Office (GAO), Nuclear Power Plants: NRC Should Take Actions to Fully Consider the Potential Effects of Climate Change, U.S. GAO report to Congressional requesters, GAO-24-106326, Apr 2, 2024. https://www.gao.gov/assets/d24106326.pdf.
(Most Headings and all NOTEs and COMMENTs are added by CIECP. The summary reorganizes order of material presented in the report under the below headings to enable easier finding of points relevant to specific topics. Some points are repeated under multiple headings.)
Aging Plants & License Extensions Appendix III Climate & Natural Events Factored into GAO Analysis Cold Flooding, Hurricanes, Storm Surge, and Sea Level Rise
-Flooding & Storm Surge
-Sea level rise
2 Heat & Drought Seismic Risk - Earthquakes Wildfire Disaster Mitigation & Emergency Response Capability - Diverse and Flexible Coping Strategies (FLEX) & Strategic Alliance for FLEX Emergency Response (SAFER) Centers NRC Oversight & Regulatory Regime NRC Reliance on Historical Data GAO FINDINGS Licensing License renewals Inspections NRC RESPONSE TO DRAFT VERSION OF GAO REPORT (Attached to final GAO Report as Appendix IV: Comments from the Nuclear Regulatory Commission)
[To examine how climate change is expected to affect nuclear power plants, the GAO conducted a literature review of articles and reports related to the effects of climate change on nuclear power plants. On the basis of this method, the office reviewed prior GAO reports, the fourth and fifth U.S. Global Change Research Programs National Climate Assessments (NCA), and 36 articles in the literature.
(The GAO report excluded consideration of experimental and test reactors.)
The midcentury time frame was selected as a key focus because it captures potential hazard effects during the period in which most US nuclear plants are likely to remain operational.
As of August 2023, 93 commercial nuclear reactors at 54 sites in 28 states were operating in the US. The plants have an average age of 42 years. As of July 2023, 21 shutdown plants had high level nuclear waste stored onsite in spent fuel pools or in dry casks. Most plants are located next to lakes, rivers, or the ocean.
Climate change is expected to affect every aspect of the electricity grid: from generation, transmission, and distribution to electricity demand.
Operation of the cooling pumps and other systems which reactors rely on for key safety and operational functions requires a reliable source of electric power. Nuclear power plants normally rely on offsite power; i.e., the electricity grid to which they are connected.
[P]ower outages can have significant cascading effects on critical sectors and electric service disruptions can significantly affect the reliability of other parts of the energy sector. These losses are of special concern because outages caused by climate effects can be widespread and affect large geographic areas all at once, according to the Department of Energy. (p 8, citing, GAO, Electricity Grid Resilience: Climate Change Is Expected to Have Far-Reaching Effects and DOE and FERC Should Take Actions, GAO-21-346, Mar 5, 2021)
3 Loss of access to offsite power requires nuclear plants to rely on backup power sources, such as diesel generators, for power. The loss of power and ability to pump cooling water can have a significant adverse impact on a plants ability to safely shut down and maintain safe shutdown conditions. This could result in damage to a reactors core and potentially release radiological material into the environment. (p 9)
Spent nuclear fuel can remain onsite long after a reactor permanently shuts down. (p 9)
Aging Plants & License Extensions NRC can issue a license to operate a nuclear power reactor for up to 40 years and can renew a license for up to 20 additional years. A renewed license may be subsequently renewed for up to another 20 years, allowing a reactor to operate for up to a total of 80 years. (p 9)
As of January 2024, NRC had issued license renewals to 49 of the 54 operating nuclear power plants. This means that most plants are operating on the basis of natural hazard risk assessments that are over 40 years old. (p 36)
As of December 2023, NRC had issued subsequent license renewals for 6 reactors at 3 nuclear power plants. (p 9)
Appendix III Appendix III: Nuclear Power Plant Exposure to Selected Natural Hazards contains:
- Table1 Potential Exposure to Current and Future Hazards at Operating Nuclear Power Plants (pp 55-61)
- Table 2 Potential Exposure to Current and Future Hazards at Shutdown Nuclear Power Plants (pp 62-63)
Climate & Natural Events Factored into GAO Analysis The GAO audit included examination of national-level data sets from relevant federal agencies for 6 natural conditions likely to be exacerbated by climate change: flooding, extreme cold, extreme heat, sea level rise, storm surge from hurricanes, and wildfire. GAO did not analyze drought data because of insufficient national-level geospatial data relevant to nuclear sites.
{-- NOTE: the fifth NCA was released on Nov 14, 2023.}
{--NOTE: GAO did not engage in a detailed review of risks to nuclear from climate related phenomenon. Nor did the GAO discuss risk multipliers or review the elevation/exacerbation of risk from combinations of events which are increasingly occurring concurrently or in rapid succession, sometimes over very wide geographic regions.}
{--COMMENT: Besides the six hazards of GAO focus (cold, flooding, heat, sea level rise, storm surges from hurricanes, and wildfires), climate change introduces a wide array of other conditions and phenomena that have been inadequately assessed. These include:
biota/ecosystem change; freeze-thaw cycling; erosion; excessive precipitation (not just extreme
4 precipitation); extreme snowstorms; increasingly powerful and/or wide-ranging tornadoes; subsidence (i.e. sinking of an area of land including sinkholes); water chemistry composition alteration (e.g., due to warming and runoff; and wildlife changes (e.g., increases in jellyfish infestations which can clog intake pipes). Even beyond the level of risk posed by individual phenomena and natural hazard events, are the risks posed by combined and interacting conditions and events. For example, excessive precipitation can accelerate corrosion of buried plant components, systems, and infrastructure which may then fail when stressed by a natural disaster}
{--COMMENT: Failure of dams and levees can present flood risks not contemplated in FEMA floodplain maps. FEMA floodplain maps also fail to depict small areas where stream overflows and flash floodings may occur or where flooding may suddenly emerge as a risk due to alteration of the landscape.}
{--COMMENT: Wildfire risk beyond the focal point of U.S. Forest Service data extends to human-added fuel sources and built infrastructure such as electric power lines and fossil infrastructure that can ignite blazes and add combustible components to an areas risk profile.
Wildfire risk to plant sites also comes from the smoke, which can introduce particulates into system and obviously impact on-site worker capabilities, even if flames are not near the plant site.}
Cold To analyze projected exposure to extreme cold hazards, GAO used data from the fourth NCA on the projected exposure to maximum and minimum temperatures by the midcentury (2036-2065) under both a low-and high-emission scenario.
Cold temperatures can diminish cooling capacity and lead to the loss of offsite power, posing risks to nuclear power plants. Specifically, extreme cold conditions may create ice that could block a plants cooling water intake system, potentially reducing the supply of cooling water to safety-related systems and components. In addition, frozen precipitation can cause icing of power lines and lead to full or partial loss of off-site power, potentially forcing a plant to rely on backup diesel that may be vulnerable to extremely cold air temperatures. (p 25)
Flooding, Hurricanes, Storm Surge, and Sea Level Rise About 63% of US nuclear power plants (47 of 75) are located in areas with exposure to category 4 or 5 hurricane storm surge or high flood hazard, and 9 are on a coastline, where NOAA projects a range of sea level increases. In addition, 20 percent of nuclear power plants (15 of
- 75) are located in areas with exposure to both Category 4 or Category 5 hurricane storm surge and high flood hazard. The NCA predicts that climate change will exacerbate all three hazards.
(p 18)
Of the 37 nuclear power plants located in a coastal region, 24 are operating and 13 are shut. Of the 9 nuclear power plants located on the coastline, 7 are operating and 2 are shut. (p 23, fn 33)
After the Fukushima Daiichi nuclear power plant accident, in 2013 and nearly annually since, NRC has hosted Probabilistic Flood Hazard Assessment workshops, in which participants from federal agencies and other organizations shared information about probabilistic assessment of extreme rainfall, flood-induced dam and levee failures, tsunami flooding, river flooding, extreme storm surge, and combined-events flooding. These workshops often share research results
5 with the public. For example, NRC contracted with the Pacific Northwest National Laboratory to publish four national and regional reports on the potential impacts of climate change, which as of 2022 have not yet led to additional NRC guidance for probabilistic flood hazard assessment.
(p 31, fn 44)
NRC does not require licensees to use climate projections data to assess future flooding risks as part of their needs assessments for Diverse and Flexible Coping Strategies (FLEX) equipment, which is intended to ensure key plant safety functions can be maintained during a beyond design basis event. (pp 36-37)
-Flooding & Storm Surge-Flooding could pose risks to nuclear power plants by, among other things, diminishing a plants cooling capacity. Flooded roads could prevent personnel, equipment, and supplies from reaching a plant. Flooding could also cause damage to buildings, equipment, and electrical systems that could require a plant to curtail operations or shut down. In addition, flood waters could interfere with heat removal from spent fuel pools by blocking ventilation ports with water.
Prolonged exposure to salt water from coastal flooding could also degrade or corrode a casks exterior, potentially posing risks to the environment and human health. (p 19)
GAOs analysis of Federal Emergency Management Agency (FEMA) data shows that 80% (60 of 75) US nuclear plants are in areas of high flood hazard and 2 are in areas of moderate flood hazard. Over a third of plants (21 of 60) in high flood hazard areas are in the South. (p 19) Of the 60 plants in high flood hazard, 42 are operating and 18 are shut. The 2 plants situated in moderate flood hazard areas are operating. (19, fn 26)
The NCA predicts heavy rainfall and flooding to become more frequent and severe across the US and climate change will continue to exacerbate hurricane storm surge, rainfall, and flood events in coastal areas. (p 19)
GAO analysis of NOAA data shows about 23% of nuclear power plants (17 of 75) are located in areas at risk of inundation by storm surge from Category 4 or Category 5 hurricanes. All of these plants are in the East and South, with 6 exposed to Category 5 hurricanes being in the South.
The NCA expects climate change to heighten hurricane storm surges, wind speeds, and rainfall rates. (p 21)
Of the 17 plants located in areas that may be inundated by storm surge from Category 4 or 5 hurricanes, 11 are operating and 6 are shut. (p 21, fn 27)
For the West Coast, storm surge data were only available for Southern California. (p 21, fn 27)
NOAA uses a hurricane storm surge model called Sea, Lake, and Overland Surges that estimates the maximum extent of storm surge at high tide. (p 21, fn 28)
The NCA expects climate change will heighten hurricane storm surges, wind speeds, and rainfall rates. (p 21)
Storm surge impacts to nuclear power plants would depend on several factors, including a plants elevation and protective measures. (p 21, fn 29)
-Sea level rise-
6 Sea level rise could affect nuclear power plants by contributing to greater storm surges and flooding. According to NOAA officials, a rise in sea level can increase corrosion from saltwater intrusion and lead to chronic long-term erosion of coastal cliffs, where some plants are located.
According to a NOAA report, over the next 30 years sea levels will continue to rise as climate change warms glaciers and ice sheets, causing additional water mass to enter the ocean. The rise in sea level is expected to increase coastal flooding by contributing to higher tides and storm surges that reach further inland, potentially affecting coastal nuclear power plants. (p 22-
- 23)
NOAA data indicates that about half of US nuclear power plants (37 of 75) are in a coastal region, with 9 located on the coastline. Projected coastal sea level rise in 2050 varies by region, (from 0.5 in the Northwest to 1.9 in the Western Gulf). (p 23)
In addition, sea level rise may increase saltwater intrusion into the coastal rivers or groundwater aquifers that some nuclear power plants use for service or potable water. (p 23)
NOAA officials told GAO that Turkey Point Nuclear Generating Station is an example of a plant where sea level rise could lead to saltwater intrusion into the plants cooling canals. NOAA officials also said that Southern California is an example of an area where cliffs consist of unconsolidated rock which is particularly vulnerable to long-term erosion from sea level rise.
(p 23, fn 31)
According to a U.S. Environmental Protection Agency (EPA) source, sea level rise may increase river levels and risk of saltwater intrusion into rivers and coastal groundwater aquifers, especially during dry periods. According to NRCs Generic Environmental Impact Statement for License Renewal of Nuclear Plants, saltwater intrusion into groundwater aquifers can degrade the quality of groundwater used for potable and service water at nuclear power plants. (p 23, fn 34, citing See NUREG-1437, Vol. 1, Revision 1)
Heat & Drought To analyze projected exposure to extreme heat hazards, GAO used data from the fourth NCA on the projected exposure to maximum and minimum temperatures by the midcentury (2036-2065) under both a low-and high-emission scenario.
Heat and drought can affect the water used for cooling. Specifically, high temperatures may increase the temperature and drought can reduce the supply of source water.
If a plant has an insufficient supply of cooling water or its cooling water approaches or exceeds the maximum allowable temperature for cooling certain reactor components, a licensee may need to temporarily limit or stop operations to ensure plant safety. Higher temperatures in the bodies of water into which nuclear power plants discharge cooling water may also require a plant to limit or temporarily stop operations to comply with laws designed to protect aquatic ecosystems and wildlife. In addition, high temperatures can also degrade the performance or cause failure of pumps and other equipment, reduce the lifetime of plant components, and reduce the overall efficiency of power plants. Warmer temperatures may also increase levels of certain algae or other biological material which can block cooling water systems and lead to reduced production or a temporary plant shutdown. (p 14)
7 Both operating and shutdown nuclear power plants are located in areas where climate change is projected to increase measures of heat, including daily and average maximum temperature.
The effects of climate change on maximum temperatures are projected to be most severe in the South, where a third of the plants are located. The plants in the South are projected to experience an annual average of 21 to 31 days with higher maximum temperatures than historical highs. (p 15)
Climate change is also expected to increase drought intensity in some regions, especially the Southwest, where 2 operating and 4 shutdown nuclear power plants are located. (p 15)
Seismic Risk - Earthquakes NRC is reviewing new seismic information from a 2018 report to assess updated seismic hazards at the nuclear power plants located in the region addressed by the report. See Pacific Earthquake Engineering Research Center, Central and Eastern North America Ground-Motion Characterization: NGA-East Final Report, (Berkeley, CA: December 2018). After reviewing this report, NRC determined that 13 nuclear power plants located in the central and eastern United States needed further assessment. Based on assessments conducted as of March 2024, NRC determined that no regulatory action was needed. (p 32, fn 47)
Wildfire Climate change has already contributed to unprecedented wildfire events in the Southwest and NCA projects increased drought risk, heatwaves, and more frequent and larger wildfires. (p
- 16)
Wildfires pose several risks to nuclear power plants, including increasing the potential for onsite fires that could damage plant infrastructure, damaging transmission lines that deliver electricity to plants, and causing a loss of power that could require plants to shut down. Wildfires and the smoke they produce could also hinder or prevent nuclear power plant personnel and supplies from getting to a plant. (p 16)
GAO analysis of U.S. Forest Service data shows that about 20% of nuclear power plants (16 of
- 75) are sited in areas with high or very high wildfire potential. More than one-third of nuclear power plants in the South (9 of 25) and West (3 of eight) are in areas with high or very high wildfire potential. (p 16)
The Strategic Alliance for FLEX Emergency Response (SAFER) centers that the nuclear industry uses to maintain emergency equipment for provision to all nuclear plants as a backup to primary onsite backup equipment are located in Phoenix, Arizona and Memphis, Tennessee (p 33) Both SAFER centers are in areas projected to see an increase in daily temperature from 3.6 to 4.9 degrees and the Phoenix SAFER center is in an area with high to very high wildfire risk. (p 33, fn 49)
Disaster Mitigation & Emergency Response Capability - Diverse and Flexible Coping Strategies (FLEX) & Strategic Alliance for FLEX Emergency Response (SAFER) Centers After Fukushima, in 2012, NRC issued an order requiring all licensees and nuclear power plant construction permit holders to ensure key plant safety functions could be maintained during a beyond design basis event. In response, the nuclear industry developed the Diverse and
8 Flexible Coping Strategies (FLEX) Implementation Guide, which NRC endorsed as one method to comply with the 2012 order. FLEX is a strategy that uses controls, procedures, and backup equipment to ensure that the key safety functions related to cooling a reactors core and spent fuel, as well as containment to prevent accidental releases of radiation, are maintained if a disaster occurs at a plant. (pp 32-33, citing Nuclear Energy Institute, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, NEI 12-06, Aug 2012.)
NRC does not require licensees to use climate projections data to assess future flooding risks as part of their FLEX needs assessment. (pp 36-37)
The nuclear power industry operates two Strategic Alliance for FLEX Emergency Response (SAFER) centers - one in located in Phoenix, Arizona, and the other in Memphis, Tennessee -
that maintain emergency equipment for provision to plants as a backup to their primary onsite backup equipment. (p 33)
The SAFER centers are staffed by a private company that has contractual agreements with every US nuclear licensee to manage and deploy offsite FLEX equipment. The SAFER centers maintain generic equipment useful for multiple plants, including various types of generators and pumps, and site-specific equipment unique to certain plants. NRC determined there is reasonable assurance that equipment at the SAFER centers can be deployed to any plant in the United States within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, as specified by licensees SAFER response plans. (p 33, fn 49)
The SAFER centers are located in areas projected to see an increase in daily temperature from 3.6 to 4.9 degrees and the Phoenix SAFER center is in an area with high to very high wildfire risk. (p 33, fn 49)
NRC does not require licensees to use climate projections data to assess future flooding risks as part of their FLEX equipment needs assessments. (pp 36-37)
NRC Oversight & Regulatory Regime NRC actions to address natural hazard risks to nuclear power plants do not fully consider the potential effects of climate change. (p 27)
NRC resident inspectors verify that selected systems and components will function when affected by adverse weather. (p 28)
In May 2017, the NRC approved a process to determine the need for additional research, site-specific assessments, or regulatory action called Process for the Ongoing Assessment of Natural Hazard Information (POANHI). POANHI involves collecting and maintaining hazard information in the Natural Hazards Information Digest a database that supports POANHI and reviewing and assessing the hazard information to determine whether a hazard has a potentially significant impact on plant safety. (pp 31-32)
According to NRC officials, NRC has not taken any regulatory actions as a result of POANHI.
(p 32)
In 2019, NRC began using a Natural Hazards Information Digest as a repository for information on natural hazard-related events at or near nuclear power plants. The database, which is supposed to support POANHI, includes historical site-specific events and captures
9 documentation provided by licensees in response to site hazard reevaluations and plant inspections and other information. (p 32, fn 45)
Under NRC policy, POANHI assessment is supposed to determine whether new information about a hazard indicates it could adversely affect the capability of a plants structures, systems, and components to perform their intended safety functions. (p 32, fn 46)
GAO observes that POANHI has several limitations as a mechanism for comprehensively identifying and assessing climate risks. (p 37) While POANHI requires continuous evaluation of new information on natural hazards, NRC officials said that the agency conducts assessments for only one hazard at a time. The agency also does not have a schedule for reviewing natural hazards beyond an assessment of seismic hazards currently underway. As such, POANHI is used to react to new hazard information or events when NRC staff become aware of them. (p
- 37)
In addition, NRC
- has not implemented POANHI and the Natural Hazards Information Digest at all levels of the agency,
- has not documented the new hazard information it reviews as part of POANHI, and
- has not documented the way it incorporates climate projections data to determine whether to initiate a POANHI assessment, require additional plant-specific assessments, conduct an overall hazard reevaluation, or take regulatory action. (p 37)
Several regional branch chiefs and resident inspectors interviewed by the GAO were unaware of POANHI and this information database. (p 37)
NRC Reliance on Historical Data For initial licensing of new reactors 10 C.F.R. § 100.20(c) requires NRC to consider the geology, hydrology, meteorology, and seismology of a site and to estimate the maximum probable flood using historical data. Under 10 C.F.R. § 60.2, the design basis of plants requires estimate of severe natural events based on historical and physical data. Also, 10 C.F.R. Part 50, Appendix A, General Design for Nuclear Power Plants, Criterion 2Design Bases for Protection Against Natural Phenomena, the design basis for the reactors safety structures, systems, and components must include, inter alia, consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated. (p 38, fn 57)
NRC officials interviewed told the GAO that NRC probabilistic risk assessments (PRAs) use current estimates of the probability of external events, but neither licensee nor NRC assessments incorporate climate projections. NRC officials said that while it is both technical and feasible to update these models with the latest information reflecting their current state of knowledge, using climate projections data would increase uncertainty in the results of the probabilistic risk assessments, and no historical trends have emerged to suggest the need to adjust these. (p 35, fn 50)
NRC officials told [GAO] that they use historical data in licensing and oversight processes rather than climate projections data, in part because regulations require NRC to use available historical data to assess the safety of the reactor site and design and they believe these data are reliable and sufficient for developing an adequate margin of safety for plants. (p 38)
10 According to NRC officials, using site-specific climate projections data for extreme hazard levels in nuclear power plant design and safety reviews is challenging because of the uncertainty associated with applying these data to specific sites. Without incorporating the best available information into its licensing and oversight processes, it is unclear whether the safety margins for nuclear power plants established during the licensing periodin most cases over 40 years agoare adequate to address the risks that climate change poses to plants. (pp 38-39)
GAO FINDINGS NRCs actions to address risks to nuclear power plants from natural hazards in its licensing, license renewal, and inspection processes do not fully consider the potential increased risks from natural hazards that may be exacerbated by climate change. (p 34)
Licensing.
NRC does not use climate projections data to identify and assess risk as part of the safety reviews or probabilistic risk. assessment reviews it conducts during the initial licensing process.
Rather, NRC uses historical data to extrapolate the future risks of natural hazards that may occur during the lifetime of a nuclear power plant. Extrapolating historical data into the future assumes that existing climatological trends will continue. NRC officials we interviewed told us that they review regional climate projections information for some hazards but do not incorporate site-specific climate projections data, which include hazard assessments, design bases, or determining the adequate safety margin for plants. For example, NRC officials said they review the projected average increase in temperature that applies to a multistate region according to the NCA designation and compare that with the maximum temperature limits for a particular plant in that region. The officials said that they do not use data on the projected temperature increase to inform licensing decisions at the plant site itself. (pp 34-35)
Climate change is altering the characteristics of many extreme weather events. According to the NCA, some extreme weather events have already become more frequent, intense, widespread, or of longer duration. Many are expected to continue to worsen. (p 35, fn 52)
Following an initial 40-year licensing period, NRC does not reevaluate natural hazard risks, including climate-related risks, to update the safety reviews required for the license renewal process. (pp 35-36)
NRC officials interviewed told the GAO that NRC probabilistic risk assessments (PRAs) use current estimates of the probability of external events, but neither licensee nor NRC assessments incorporate climate projections. NRC officials said that while it is both technical and feasible to update these models with the latest information reflecting their current state of knowledge, using climate projections data would increase uncertainty in the results of the probabilistic risk assessments, and no historical trends have emerged to suggest the need to adjust these. (p 35, fn 50)
As of January 2024, NRC had issued license renewals to 49 of the 54 operating nuclear power plants, meaning most plants are operating on the basis of assessments of natural hazard risk that are over 40 years old. (p 36)
11 Inspections.
NRC resident inspectors are responsible for focusing on the immediate day-to-day safety of plants rather than on potential long-term safety risks. Inspections do not include an assessment of future climate projections data. In addition, while NRC sometimes conducts additional inspections using outside teamsincluding staff from NRC regional officesto address recent events or emerging issues related to safety, these inspections also do not focus on long-term safety risks. (p 36)
NRC officials interviewed by GAO expressed their belief that conservatism, defense-in-depth, and safety margins adequately address the risks posed by climate change to the safety of nuclear power plants. However, NRC has not conducted an assessment to demonstrate that this is the case. (p 36)
NRC officials told [GAO] that they use historical data in licensing and oversight processes rather than climate projections data, in part because regulations require NRC to use available historical data to assess the safety of the reactor site and design and they believe these data are reliable and sufficient for developing an adequate margin of safety for plants. (p 38)
Moreover, NRC actions taken to address risks to nuclear power plants from natural hazards post-Fukushima did not fully consider the effects of climate change. Specifically, NRC required licensees to assess flooding risk and enhance safety and emergency equipment, but NRC did not require licensees to use climate projections data to assess future flooding risks as part of these assessments or in the FLEX equipment needs assessments. (pp 36-37)
Further, POANHI has several limitations as a mechanism for comprehensively identifying and assessing climate risks.
(p 37)
NRC officials told us that while POANHI requires continuous evaluation of new information on natural hazards, NRC conducts POANHI assessments for one hazard at a time, and the agency does not have a schedule for reviewing natural hazards beyond the assessment of seismic hazards currently underway. As such, POANHI is used to react to new hazard information or events when NRC staff become aware of them. (p 37)
NRC has not documented the new hazard information it reviews as part of POANHI or the way it incorporates climate projections data to determine whether to initiate a POANHI assessment, require additional plant-specific assessments, conduct an overall hazard reevaluation, or take regulatory action. (p 37)
NRC has not implemented POANHI and the Natural Hazards Information Digest at all levels of the agency. For example, several regional branch chiefs and resident inspectors we interviewed were unaware of POANHI and this information database. (p 37)
NRC has not documented the new hazard information it reviews as part of POANHI or the way it incorporates climate projections data to determine whether to initiate a POANHI assessment, require additional plant-specific assessments, conduct an overall hazard reevaluation, or take regulatory action. (p 37)
12 NRC has not implemented POANHI and the Natural Hazards Information Digest at all levels of the agency. For example, several regional branch chiefs and resident inspectors we interviewed were unaware of POANHI and this information database. (p 37)
Commercial nuclear power plants in the United States were licensed and built an average of 42 years ago, and weather patterns and climate related risks to their safety and operations have changed since their construction. Climate change is expected to exacerbate natural hazards such as heat, drought, wildfires, flooding, hurricanes, sea level rise, and extreme cold weather eventsthat can affect nuclear power plant safety and operations in various ways. Some of these effects are already occurring, and many are expected to continue to worsen. (p 39)
However, NRC does not use climate projections data to identify and assess risk as part of the safety reviews it conducts or the probabilistic risk assessments it reviews during the initial licensing process. NRC has also not fully developed POANHI, which the agency relies on to identify and assess changes in natural hazard risks, including climate change. (p 39)
Specifically, assessing whether its licensing and oversight processes adequately consider climate risks to nuclear power plants and developing and implementing a plan to address any gaps identified would help the agency do so. As NRC makes licensing, license renewal, and oversight decisions, adopting an approach that incorporates the best available information on climate risks and ways that those risks may affect nuclear plants, would provide greater assurance that licensees have adequate measures to address risks from climate change. (p
- 40)
NRC has not conducted an assessment to demonstrate that the safety margins for nuclear power plants established during the licensing period are adequate to address the risks that climate change poses to plants. According to the NCA, many of the climate conditions and impacts experienced in the United States today are unprecedented for thousands of years.
Across all regions of the United States, extremes, including heat, drought, flooding, wildfire, and hurricanes, are becoming more frequent and/or severe, with a cascade of effects in every part of the country. (p 40)
The GAO believes that the NRC cannot fully consider potential climate change effects on plants without using the best available informationincluding climate projections datain its licensing and oversight processes. (pp 40-41)
NRC RESPONSE TO DRAFT VERSION OF GAO REPORT (Attached to final GAO Report as Appendix IV: Comments from the Nuclear Regulatory Commission)
In a March 7, 2024 letter signed by the NRCs Acting Executive Director for Operations, Ray V.
Furstenau, the NRC responded to a draft version of the GAO Report. In this letter,, the agency expressed disagreement with the conclusion that it does not address the impacts of climate change.
In effect, the layers of conservatism and defense in depth incorporated into NRCs processes provide reasonable assurance regarding any plausible natural hazard and combinations at a site for the licensed operational lifetime of the reactor, including those that could result from climate change. Specifically, the processes, tools, methods, models, data, and additional
13 margins provide reasonable assurance of the ability to withstand or mitigate projected changes in natural hazards. (p 65, in Appendix IV)
It is also important to note that the NRCs mission is focused on nuclear safety; as such, we cannot impose requirements that would increase energy resilience or require consideration of potential future climate impacts without a sufficient nuclear safety justification. This is an important distinction since the predominant concerns expressed often in the draft report are that a licensees operations may be disrupted more frequently by climate change and that the NRC should more fully consider future climate projections. The NRC is focused on nuclear safety and any potential increase in the risk of a radiological release, consistent with the NRCs mandate.
(p 1 of letter, at p 65, in Appendix IV)
Mr. Furstenau protests the lack of focus during the audit and lack of mention in GAOs report of the NRCs proactive approach to safety reviews to support the licensing of new reactors which, he asserts, makes a significant contribution by the NRC to climate resilience because the NRC is licensing new energy sources that are an alternative to fossil-fuel-based plants. (p 2 of letter, at p 66, in Appendix IV)
Mr. Furstenau recommends that the GAO reference NRCs contribution to climate resilience via the proactive planning and implementation of new and advanced reactor licensing and license renewals. (p 2 of letter, at p 66, in Appendix IV)
{--NOTE: Raymond V. Furstenau joined the NRC in 2018 as the Director of Nuclear Regulatory Research after serving at the DOE as Associate Principal Deputy Assistant Secretary and Central Technical Authority of the Office of Nuclear Energy (DOE-NE). He holds a MS in Nuclear Science and Engineering from Idaho State University.}