Commitments and Contingencies	9 Months Ended
Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Indemnities Edison International and SCE have various financial and performance guarantees and indemnity agreements, which are issued in the normal course of business. Edison International and SCE have provided indemnifications through contracts entered into in the normal course of business. These are primarily indemnifications against adverse litigation outcomes in connection with underwriting agreements, and indemnities for specified environmental liabilities and income taxes with respect to assets sold. Edison International's and SCE's obligations under these agreements may or may not be limited in terms of time and/or amount, and in some instances Edison International and SCE may have recourse against third parties. Edison International and SCE have not recorded a liability related to these indemnities. The overall maximum amount of the obligations under these indemnifications cannot be reasonably estimated. SCE has indemnified the City of Redlands, California in connection with the Mountainview power plant's California Energy Commission permit for cleanup or associated actions related to groundwater contaminated by perchlorate due to the disposal of filter cake at the City's solid waste landfill. The obligations under this agreement are not limited to a specific time period or subject to a maximum liability. SCE has not recorded a liability related to this indemnity. Contingencies In addition to the matters disclosed in these Notes, Edison International and SCE are involved in other legal, tax, and regulatory proceedings before various courts and governmental agencies regarding matters arising in the ordinary course of business. Edison International and SCE believe the outcome of these other proceedings will not, individually or in the aggregate, materially affect its financial position, results of operations and cash flows. Southern California Wildfires In December 2017, several wind-driven wildfires (the "December 2017 Wildfires") impacted portions of SCE's service territory and caused substantial damage to both residential and business properties and service outages for SCE customers. The largest of these fires, known as the Thomas Fire, originated in Ventura County and burned acreage located in both Ventura and Santa Barbara Counties. According to the most recent California Department of Forestry and Fire Protection ("CAL FIRE") incident information reports, the Thomas Fire burned over 280,000 acres, destroyed an estimated 1,063 structures, damaged an estimated 280 structures and resulted in two fatalities. As of September 30, 2018, SCE had incurred approximately $84 million of capital expenditures related to restoration of service resulting from the December 2017 Wildfires and the Montecito Mudslides (as defined below). Determining wildfire origin and cause is often a complex and time-consuming process and several investigations into the facts and circumstances of the Thomas Fire are believed to be ongoing. SCE has been advised that the origins and causes of the fire are being investigated by CAL FIRE and the Ventura County Fire Department. In connection with its investigation of the Thomas Fire, CAL FIRE has removed and retained certain of SCE's equipment that was located in the general vicinity of suspected ignition points of the fire. SCE expects that the Ventura County Fire Department and/or CAL FIRE will ultimately issue reports concerning the origins and causes of the Thomas Fire but cannot predict when these reports will be released. The CPUC's Safety Enforcement Division ("SED") is also conducting an investigation to assess the compliance of SCE and its facilities with applicable rules and regulations in areas impacted by the Thomas Fire. SCE cannot predict when the investigations of CAL FIRE, the Ventura County Fire Department or the SED, will be completed. As it does in all wildfire matters in which its facilities may or are alleged to be involved, SCE is conducting its own review into the facts and circumstances of the Thomas Fire. SCE's internal review of the Thomas Fire is complex and examines various matters including possible ignition points, the location of those ignition points, fire progression and the attribution of damages to fires with separate ignition points. As its review of the Thomas Fire progresses and the Thomas Fire litigation process continues, SCE expects to obtain and review additional information, materials and physical information that are in the possession of CAL FIRE and other parties, including SCE equipment that has been retained by CAL FIRE. Based on currently available information, SCE believes that the Thomas Fire had at least two separate ignition points, one near Koenigstein Road in the City of Santa Paula and the other somewhere in the Anlauf Canyon area of Ventura County. With respect to the Koenigstein Road ignition point, witnesses have reported that a fire ignited in the vicinity of an SCE power pole, and SCE believes that its equipment was associated with this ignition. CAL FIRE has removed equipment located in the general vicinity of Koenigstein Road and SCE has not been able to inspect it. SCE is continuing to assess the progression of the fire from the Koenigstein Road ignition point and the extent of damages that may be attributable to that ignition. At this time, based on available information, SCE has not determined whether the ignition in the Anlauf Canyon area involved SCE equipment. CAL FIRE has removed equipment located in the Anlauf Canyon area and SCE has not been able to inspect it. Edison International and SCE expect to incur a material loss in connection with the Thomas Fire. However, given the uncertainty as to the contributing causes of the Thomas Fire, the complexities associated with multiple ignition points and the potential for separate damages to be attributable to fires ignited at separate ignition points, Edison International and SCE are currently unable to reasonably estimate a range of losses that may be incurred in connection with the Thomas Fire, but anticipate being able to do so when sufficient additional information becomes available. Such additional information is expected to become available from multiple external sources, during the course of litigation, and from SCE's ongoing internal review, including, among other things, information regarding the extent of damages that may be attributable to any ignition determined to have been substantially caused by SCE's equipment, information that may be obtained from the equipment in CAL FIRE's possession and information pertaining to fire progression, suppression activities, alleged damages and insurance claims. The extent of potential liability for December 2017 Wildfire-related damages depends on a number of factors, including whether SCE substantially caused, or contributed to, the damages and whether parties seeking recovery of damages will be required to show negligence in addition to causation. Certain California courts have previously found utilities to be strictly liable for property damage, regardless of fault, by applying the theory of inverse condemnation when a utility's facilities were determined to be a substantial cause of a wildfire that caused the property damage. The rationale stated by these courts for applying this theory to investor-owned utilities is that property damages resulting from a public improvement, such as the distribution of electricity, can be spread across the larger community that benefited from such improvement. However, in November 2017, the CPUC issued a decision denying SDG&E's request to include in its rates uninsured wildfire-related costs arising from several 2007 fires, finding that SDG&E did not prudently manage and operate its facilities prior to or at the outset of the 2007 wildfires. In July 2018, the CPUC denied both SDG&E's application for rehearing on its cost recovery request and a joint application for rehearing filed by SCE and PG&E limited to the applicability of inverse condemnation principles in the same proceeding. SDG&E has petitioned the California Court of Appeal to review the CPUC's denial of SDG&E's application. SCE has filed an amicus brief in support of SDG&E's position on the applicability of inverse condemnation. The petition, which is being opposed by the CPUC and other parties, remains pending. When inverse condemnation is held to be applicable to a utility, the utility may be held strictly liable for property damages and associated interest and attorneys' fees. If inverse condemnation is held to be inapplicable to SCE in connection with the December 2017 Wildfires, SCE could be held liable for property damages and associated interest if the property damages were found to have been proximately caused by SCE's alleged negligence. If SCE is found negligent, SCE could also be held liable for, among other things, fire suppression costs, business interruption losses, evacuation costs, medical expenses, and personal injury/wrongful death claims. These potential liabilities, in the aggregate, will be material. Additionally, SCE could potentially be subject to fines for alleged violations of CPUC rules and laws in connection with the December 2017 Wildfires. SCE is aware of multiple lawsuits filed related to the Thomas Fire naming SCE as a defendant. A number of the lawsuits also name Edison International as a defendant and some of the lawsuits were filed as purported class actions. The lawsuits, which have been filed in the superior courts of Ventura, Santa Barbara and Los Angeles Counties allege, among other things, negligence, inverse condemnation, trespass, private nuisance, and violations of the public utilities and health and safety codes. By order of the Chair of the California Judicial Council, the lawsuits are being coordinated in the Los Angeles Superior Court. On October 4, 2018, the Superior Court denied Edison International's and SCE's challenge to the application of inverse condemnation to SCE. SCE is assessing the availability of potential challenges to this ruling. SCE expects to be the subject of additional lawsuits related to the Thomas Fire. The litigation could take a number of years to be resolved because of the complexity of the matters and number of plaintiffs. Additionally, in July 2018 and September 2018, two separate derivative lawsuits for breach of fiduciary duties and unjust enrichment were filed in the Los Angeles Superior Court against certain current and former members of the Boards of Directors of Edison International and SCE (collectively, the "Individual Defendants"). Edison International and SCE are identified as nominal defendants in those actions. The derivative lawsuits generally allege that the Individual Defendants violated their fiduciary duties by causing or allowing SCE to operate in an unsafe manner in violation of relevant regulations, resulting in substantial liability and damage from the December 2017 Wildfires and the Montecito Mudslides. For events that occurred in 2017, principally the December 2017 Wildfires, SCE has approximately $1 billion of wildfire-specific insurance coverage, subject to a self-insured retention of $10 million per occurrence. Various coverage limitations within the policies that make up SCE's wildfire insurance coverage could result in material self-insured costs in the event of multiple wildfire occurrences during a policy period. Should responsibility for a significant portion of the damages related to the December 2017 Wildfires be attributed to SCE, SCE's insurance may not be sufficient to cover all such damages. In addition, SCE may not be authorized to recover some or all of its uninsured damages through electric service rates if, for example, the CPUC finds that the damages were incurred because SCE did not prudently manage its facilities. Edison International and SCE are pursuing legislative, regulatory and legal strategies to address the application of a strict liability standard to wildfire-related damages without the ability to recover resulting damages in rates. In September 2018, California Senate Bill 901 ("SB 901") was signed by the Governor of California. Although SB 901 does not address the strict liability standard imposed by courts in inverse condemnation actions, the bill as enacted introduces a number of considerations the CPUC can apply to determine whether costs are recoverable in rates for wildfires occurring on or after January 1, 2019, including, among other things, the utility's actions, circumstances beyond the utility's control and the impact of extreme climate conditions. SB 901 requires investor-owned utilities to prepare annually, for CPUC approval, wildfire risk mitigation plans, and, compliance with an approved plan is one factor the CPUC can consider in addressing cost recovery. SB 901 also calls for a commission on Catastrophic Wildfire Cost and Recovery to be formed to examine, among other things, the allocation of catastrophic wildfire costs in an equitable manner. Edison International and SCE cannot predict whether or when a comprehensive solution mitigating the significant risk faced by a California investor-owned utility related to wildfires will be achieved. Current Wildfire Insurance Coverage SCE has approximately $1 billion of wildfire-specific insurance coverage, subject to a self-insured retention of $10 million per occurrence, for events that may occur during the period June 1, 2018 through May 31, 2019. SCE may obtain additional wildfire insurance for portions of this time period in the future. Various coverage limitations within the policies that make up SCE's wildfire insurance coverage could result in material self-insured costs in the event of multiple wildfire occurrences during a policy period or in the event of an exceptionally large wildfire. SCE's cost of obtaining wildfire insurance coverage has increased significantly as a result of, among other things, the December 2017 Wildfires. Based on policies currently in effect, SCE anticipates that its wildfire insurance expense, prior to any regulatory deferrals, will total approximately $237 million during 2018. SCE has requested approval from the CPUC for regulatory mechanisms to track and recover wildfire insurance premiums in excess of the amounts that are ultimately approved in the 2018 GRC decision. As of September 30, 2018, SCE has a regulatory asset of $63 million related to wildfire insurance costs and believes that such amounts are probable of recovery. Montecito Mudslides In January 2018, torrential rains in Santa Barbara County produced mudslides and flooding in Montecito and surrounding areas (the "Montecito Mudslides"). According to Santa Barbara County initial reports, the Montecito Mudslides destroyed an estimated 135 structures, damaged an estimated 324 structures, and resulted in at least 21 fatalities, with two additional fatalities presumed. Of the lawsuits mentioned above, several allege that SCE has responsibility for the Thomas Fire and that the Thomas Fire proximately caused the Montecito Mudslides, resulting in the plaintiffs' claimed damages. Some of the Montecito Mudslides lawsuits also name Edison International as a defendant. In addition to other causes of action, some of the Montecito Mudslides lawsuits also allege personal injury and wrongful death. By order of the Chair of the California Judicial Council, the Thomas Fire and Montecito Mudslides lawsuits are being coordinated in the Los Angeles Superior Court. SCE expects that additional lawsuits related to the Montecito Mudslides will be filed. The inquiry into whether the Thomas Fire proximately caused or contributed to the Montecito Mudslides, the source of ignition of the portion of the Thomas fire that burned through the Montecito area and other factors that contributed to the Montecito Mudslides is complex and time consuming. Many other factors, including, among other things, weather conditions and insufficiently or improperly designed and maintained roads, bridges and other channel crossings, could have contributed to or exacerbated the losses that resulted from the Montecito Mudslides. While SCE is not aware of any governmental agency that is investigating the causes of the Montecito Mudslides, SCE is conducting its own review of the factors that potentially contributed to the losses that resulted from the Montecito Mudslides. At this time, based on available information, SCE has not been able to determine the source of ignition of the portion of the Thomas fire that burned through the Montecito area. In the event that SCE is determined to have caused the fire that spread to the Montecito area, SCE cannot predict whether the courts will conclude that the Montecito Mudslides were caused or contributed to by the Thomas Fire or that SCE is liable for damages caused by the Montecito Mudslides. As a result, Edison International and SCE are currently unable to predict the outcome of the claims made against SCE and Edison International arising from the Montecito Mudslides or reasonably estimate a range of losses that may be incurred. If it is determined that SCE is liable for damages caused by the Montecito Mudslides, SCE will incur a material loss. SCE's insurance coverage for such losses may be limited to its wildfire insurance. In January 2018, SCE also had other general liability insurance coverage of approximately $450 million, but it is uncertain whether these other policies would apply to liabilities alleged to be related to the Montecito Mudslides. Additionally, if SCE is determined to be liable for a significant portion of costs associated with the Montecito Mudslides, SCE's insurance may not be sufficient to cover all such damages. In addition, SCE may not be authorized to recover some or all its uninsured damages through electric service rates if, for example, the CPUC finds that the damages were incurred because SCE did not prudently manage its facilities. If it is ultimately determined that SCE is legally responsible for damages caused by the Montecito Mudslides and inverse condemnation is held to be applicable to SCE with respect to such damages, SCE may be held liable for resulting property damages and associated interest and attorneys' fees. If inverse condemnation is held to be inapplicable to SCE in connection with the Montecito Mudslides, SCE could be held liable for property damages and associated interest if the property damages were found to have been proximately caused by SCE's alleged negligence. If SCE is found negligent, SCE could also be held liable for, among other things, business interruption losses, evacuation costs, clean-up costs, medical expenses and personal injury/wrongful death claims associated with the Montecito Mudslides. These potential liabilities, in the aggregate, will be material. SCE cannot predict whether it will be subjected to regulatory fines related to the Montecito Mudslides. Permanent Retirement of San Onofre Replacement steam generators were installed at San Onofre in 2010 and 2011. On January 31, 2012, a leak suddenly occurred in one of the heat transfer tubes in San Onofre's Unit 3 steam generators. The Unit was safely taken off-line and subsequent inspections revealed excessive tube wear. Unit 2 was off-line for a planned outage when areas of unexpected tube wear were also discovered. On June 6, 2013, SCE decided to permanently retire Units 2 and 3. San Onofre CPUC Proceeding On January 30, 2018, SCE, SDG&E, The Alliance for Nuclear Responsibility, The California Large Energy Consumers Association, California State University, Citizens Oversight dba Coalition to Decommission San Onofre, the Coalition of California Utility Employees, the Direct Access Customer Coalition, Ruth Henricks, the CPUC's Public Advocates Office, The Utility Reform Network, and Women's Energy Matters (the "OII Parties") entered into a Revised San Onofre Settlement Agreement (the "Revised San Onofre Settlement Agreement") to resolve the CPUC's investigation regarding the steam generator replacement project at San Onofre and the related outages and subsequent shutdown of San Onofre in the San Onofre Order Instituting Investigation ("OII") proceeding. In July 2018, the CPUC approved all of the terms of the Revised San Onofre Settlement Agreement other than a provision under which SCE agreed to fund $10 million for a research, development and demonstration program intended to develop technologies and methodologies to reduce greenhouse gas emissions (the "Modification"). The Revised San Onofre Settlement Agreement with the Modification became effective on August 2, 2018. All issues under consideration in the San Onofre OII have been resolved. Disallowances, Refunds and Recoveries SCE and SDG&E (the "Utilities") agreed in the Revised San Onofre Settlement Agreement to cease rate recovery of San Onofre costs once their combined remaining San Onofre regulatory assets equal $775 million. The CPUC granted SCE's request to reduce the San Onofre regulatory asset by applying approximately $72 million of proceeds received from litigation with the DOE related to DOE's failure to meet its obligation to begin accepting spent nuclear fuel from San Onofre. As a result, the combined San Onofre regulatory asset balance for the Utilities reached $775 million on December 19, 2017 and SCE ceased recovery of San Onofre costs in rates beginning on December 20, 2017. SCE has refunded to customers approximately $155 million of San Onofre-related amounts recovered in rates on and after December 20, 2017. SCE will retain amounts collected under the Prior San Onofre Settlement Agreement before December 20, 2017. SCE will also retain $47 million of proceeds received in 2017 from arbitration with MHI over MHI's delivery of faulty steam generators. See Note 11 for additional information. In the Revised San Onofre Settlement Agreement, SCE retains the right to sell its stock of nuclear fuel and not share such proceeds with customers. SCE intends to sell its nuclear fuel inventory as market conditions warrant. Proceeds from sales of nuclear fuel may be significant. The Revised San Onofre Settlement Agreement also provides for certain exclusions from the determination of SCE's ratemaking capital structure. Notwithstanding that SCE will no longer recover its San Onofre regulatory asset, the debt borrowed to finance the regulatory asset will continue to be excluded from SCE's ratemaking capital structure. Additionally, SCE may exclude the after-tax charge resulting from the implementation of the Revised San Onofre Settlement Agreement from its ratemaking capital structure. Additional Challenges related to the Settlement of San Onofre CPUC OII Proceeding A federal lawsuit challenging the CPUC's authority to permit rate recovery of San Onofre costs and an application to the CPUC for rehearing of its decision approving a November 2014 settlement agreement in the San Onofre OII were filed in November and December 2014, respectively. In April 2015, the federal lawsuit was dismissed with prejudice and the plaintiffs in that case appealed the dismissal to the Ninth Circuit Court of Appeals in May 2015. On September 10, 2018, as part of the Revised San Onofre Settlement Agreement, the plaintiffs filed a motion with the Ninth Circuit to dismiss this case with prejudice. The CPUC is opposing the motion. The Ninth Circuit has not yet ruled on the plaintiff's motion to dismiss. In July 2015, a purported securities class action lawsuit was filed in federal court against Edison International, its then Chief Executive Officer and its then Chief Financial Officer. The complaint was later amended to include SCE's former President as a defendant. The lawsuit alleges that the defendants violated the securities laws by failing to disclose that Edison International had ex parte contacts with CPUC decision-makers regarding the San Onofre OII that were either unreported or more extensive than initially reported. The complaint covers a class of persons who acquired Edison International common stock between March 21, 2014 and August 10, 2015. In September 2016, the federal court granted defendants' motion to dismiss the complaint, with an opportunity for plaintiff to amend the complaint. Plaintiff filed a second amended complaint in October 2016, which the federal court dismissed again with an opportunity for the plaintiff to amend the complaint. Plaintiff filed a third amended complaint in May 2017. In March 2018, the federal court dismissed the third amended complaint with prejudice and entered judgment in defendants' favor. Plaintiff has appealed the dismissal. In November 2015, a purported class action lawsuit was filed in federal court against Edison International, its then Chief Executive Officer and its Treasurer by an Edison International employee, alleging claims under the Employee Retirement Income Security Act. The complaint purports to be filed on behalf of a class of Edison International employees who were participants in the Edison 401(k) Savings Plan and invested in the Edison International Stock Fund between March 27, 2014 and June 24, 2015. The complaint alleges that defendants breached their fiduciary duties because they knew or should have known that investment in the Edison International Stock Fund was imprudent because the price of Edison International common stock was artificially inflated due to Edison International's alleged failure to disclose certain ex parte communications with CPUC decision-makers related to the San Onofre OII. In July 2016, the federal court granted the defendants' motion to dismiss the lawsuit with an opportunity for the plaintiff to amend her complaint. Plaintiff filed an amended complaint in July 2016, which dismissed Edison International as a named defendant and the remaining defendants filed a motion to dismiss in August 2016. In June 2017, the federal court again granted defendants' motion to dismiss the lawsuit with an opportunity for the plaintiff to amend her complaint. Plaintiff filed another amended complaint in July 2017. Defendants filed a motion to dismiss the amended complaint and, in May 2018, the federal court again granted defendants' motion to dismiss the lawsuit with an opportunity for the plaintiff to amend her complaint. Plaintiff elected not to amend her complaint and the federal court granted judgment in favor of the defendants in August 2018. Plaintiff has appealed the judgment. Edison International and SCE cannot predict the outcome of these proceedings. Environmental Remediation SCE records its environmental remediation liabilities when site assessments and/or remedial actions are probable and a range of reasonably likely cleanup costs can be estimated. SCE reviews its sites and measures the liability quarterly, by assessing a range of reasonably likely costs for each identified site using currently available information, including existing technology, presently enacted laws and regulations, experience gained at similar sites, and the probable level of involvement and financial condition of other potentially responsible parties. These estimates include costs for site investigations, remediation, operation and maintenance, monitoring, and site closure. Unless there is a single probable amount, SCE records the lower end of this reasonably likely range of costs (reflected in "Other long-term liabilities") at undiscounted amounts as timing of cash flows is uncertain. At September 30, 2018, SCE's recorded estimated minimum liability to remediate its 21 identified material sites (sites with a liability balance at September 30, 2018, in which the upper end of the range of the costs is at least $1 million) was $136 million, including $90 million related to San Onofre. In addition to these sites, SCE also has 15 immaterial sites with a liability balance as of September 30, 2018, for which the total minimum recorded liability was $4 million. Of the $140 million total environmental remediation liability for SCE, $135 million has been recorded as a regulatory asset. SCE expects to recover $43 million through an incentive mechanism that allows SCE to recover 90% of its environmental remediation costs at certain sites (SCE may request to include additional sites) and $92 million through a mechanism that allows SCE to recover 100% of the costs incurred at certain sites through customer rates. SCE's identified sites include several sites for which there is a lack of currently available information, including the nature and magnitude of contamination, and the extent, if any, that SCE may be held responsible for contributing to any costs incurred for remediating these sites. Thus, no reasonable estimate of cleanup costs can be made for these sites. The ultimate costs to clean up SCE's identified sites may vary from its recorded liability due to numerous uncertainties inherent in the estimation process, such as: the extent and nature of contamination; the scarcity of reliable data for identified sites; the varying costs of alternative cleanup methods; developments resulting from investigatory studies; the possibility of identifying additional sites; and the time periods over which site remediation is expected to occur. SCE believes that, due to these uncertainties, it is reasonably possible that cleanup costs at the identified material sites and immaterial sites could exceed its recorded liability by up to $138 million and $7 million, respectively. The upper limit of this range of costs was estimated using assumptions least favorable to SCE among a range of reasonably possible outcomes. SCE expects to clean up and mitigate its identified sites over a period of up to 30 years. Remediation costs for each of the next five years are expected to range from $7 million to $20 million. Costs incurred for the nine months ended September 30, 2018 and 2017 were $7 million and $6 million, respectively. Based upon the CPUC's regulatory treatment of environmental remediation costs incurred at SCE, SCE believes that costs ultimately recorded will not materially affect its results of operations, financial position, or cash flows. There can be no assurance, however, that future developments, including additional information about existing sites or the identification of new sites, will not require material revisions to estimates. Nuclear Insurance SCE is a member of NEIL, a mutual insurance company owned by entities with nuclear facilities. NEIL provides insurance for nuclear property damage, including damages caused by acts of terrorism up to specified limits, and for accidental outages for active facilities. The amount of nuclear property damage insurance purchased for San Onofre and Palo Verde exceeds the minimum federal requirement of $50 million and $1.06 billion, respectively. If NEIL losses at any nuclear facility covered by the arrangement were to exceed the accumulated funds for these insurance programs, SCE could be assessed retrospective premium adjustments of up to approximately $52 million per year. Federal law limits public offsite liability claims for bodily injury and property damage from a nuclear incident to the amount of available financial protection, which is currently approximately $13.1 billion for Palo Verde and $560 million for San Onofre. SCE and other owners of San Onofre and Palo Verde have purchased the maximum private primary insurance available through a Facility Form issued by American Nuclear Insurers ("ANI"). SCE withdrew from participation in the secondary insurance pool for San Onofre for offsite liability insurance effective January 5, 2018. Based on its ownership interests in Palo Verde, SCE could be required to pay a maximum of approximately $60 million per nuclear incident for future incidents. However, it would have to pay no more than approximately $9 million per future incident in any one year. SCE could be required to pay a maximum of approximately $255 million per nuclear incident and a maximum of $38 million per year per incident for liabilities arising from events prior to January 5, 2018, although SCE is not aware of any such events. For more information on nuclear insurance coverage, see Note 11 in the 2017 Form 10-K. Spent Nuclear Fuel Under federal law, the DOE is responsible for the selection and construction of a facility for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The DOE has not met its contractual obligation to accept spent nuclear fuel. Extended delays by the DOE have led to the construction of costly alternatives and associated siting and environmental issues. Currently, both San Onofre and Palo Verde have interim storage for spent nuclear fuel on site sufficient for their current license period. In June 2010, the United States Court of Federal Claims issued a decision granting SCE and the San Onofre co-owners damages of approximately $142 million (SCE share $112 million) to recover costs incurred through December 31, 2005 for the DOE's failure to meet its obligation to begin accepting spent nuclear fuel from San Onofre. SCE received payment from the federal government in the amount of the damage award. In April 2016, SCE, as operating agent, settled a lawsuit on behalf of the San Onofre owners against the DOE for $162 million (SCE share $124 million, which included reimbursement for approximately $2 million in legal and other costs), to compensate for damages caused by the DOE's failure to meet its obligation to begin accepting spent nuclear fuel for the period from January 1, 2006 to December 31, 2013. In August 2018, the CPUC approved SCE's proposal to return the SCE share of the award to customers based on the amount that customers actually contributed for fuel storage costs; resulting in approximately $105.6 million of the SCE share being returned to customers and the remaining $16.6 million being returned to shareholders. Of the $105.6 million, $71.6 million was applied against the remaining San Onofre Regulatory Asset in accordance with the Revised San Onofre Settlement Agreement. See Note 11 for further information. The April 2016 settlement also provided for a claim submission/audit process for expenses incurred from 2014 – 2016, where SCE may submit a claim for damages caused by the DOE failure to accept spent nuclear fuel each year, followed by a government audit and payment of the claim. This process made additional legal action to recover damages incurred in 2014 –2016 unnecessary. The first such claim covering damages for 2014 – 2015 was filed on September 30, 2016 for approximately $56 million. In February 2017, the DOE reviewed the 2014 – 2015 claim submission and reduced the original request to approximately $43 million (SCE share was approximately $34 million). SCE accepted the DOE's determination, and the government paid the 2014 – 2015 claim under the terms of the settlement. In October 2017, SCE filed a claim covering damages for 2016 for approximately $58 million. In May 2018, the DOE approved reimbursement of approximately $45 million (SCE share was approximately $35 million) of SCE's 2016 damages, not allowing recovery of approximately $13 million. SCE accepted the DOE's determination, and the government paid the 2016 claim under the terms of the settlement. The damages awards are subject to CPUC review as to how the amounts will be refunded among customers, shareholders, or to offset other costs.

Commitments and Contingencies

Indemnities

Edison International and SCE have various financial and performance guarantees and indemnity agreements, which are issued in the normal course of business.

Edison International and SCE have provided indemnifications through contracts entered into in the normal course of business. These are primarily indemnifications against adverse litigation outcomes in connection with underwriting agreements, and indemnities for specified environmental liabilities and income taxes with respect to assets sold. Edison International's and SCE's obligations under these agreements may or may not be limited in terms of time and/or amount, and in some instances Edison International and SCE may have recourse against third parties. Edison International and SCE have not recorded a liability related to these indemnities. The overall maximum amount of the obligations under these indemnifications cannot be reasonably estimated.

SCE has indemnified the City of Redlands, California in connection with the Mountainview power plant's California Energy Commission permit for cleanup or associated actions related to groundwater contaminated by perchlorate due to the disposal of filter cake at the City's solid waste landfill. The obligations under this agreement are not limited to a specific time period or subject to a maximum liability. SCE has not recorded a liability related to this indemnity.

Contingencies

In addition to the matters disclosed in these Notes, Edison International and SCE are involved in other legal, tax, and regulatory proceedings before various courts and governmental agencies regarding matters arising in the ordinary course of business. Edison International and SCE believe the outcome of these other proceedings will not, individually or in the aggregate, materially affect its financial position, results of operations and cash flows.

Southern California Wildfires

In December 2017, several wind-driven wildfires (the "December 2017 Wildfires") impacted portions of SCE's service territory and caused substantial damage to both residential and business properties and service outages for SCE customers. The largest of these fires, known as the Thomas Fire, originated in Ventura County and burned acreage located in both Ventura and Santa Barbara Counties. According to the most recent California Department of Forestry and Fire Protection ("CAL FIRE") incident information reports, the Thomas Fire burned over 280,000 acres, destroyed an estimated 1,063 structures, damaged an estimated 280 structures and resulted in two fatalities. As of September 30, 2018, SCE had incurred approximately $84 million of capital expenditures related to restoration of service resulting from the December 2017 Wildfires and the Montecito Mudslides (as defined below).

Determining wildfire origin and cause is often a complex and time-consuming process and several investigations into the facts and circumstances of the Thomas Fire are believed to be ongoing. SCE has been advised that the origins and causes of the fire are being investigated by CAL FIRE and the Ventura County Fire Department. In connection with its investigation of the Thomas Fire, CAL FIRE has removed and retained certain of SCE's equipment that was located in the general vicinity of suspected ignition points of the fire. SCE expects that the Ventura County Fire Department and/or CAL FIRE will ultimately issue reports concerning the origins and causes of the Thomas Fire but cannot predict when these reports will be released. The CPUC's Safety Enforcement Division ("SED") is also conducting an investigation to assess the compliance of SCE and its facilities with applicable rules and regulations in areas impacted by the Thomas Fire. SCE cannot predict when the investigations of CAL FIRE, the Ventura County Fire Department or the SED, will be completed.

As it does in all wildfire matters in which its facilities may or are alleged to be involved, SCE is conducting its own review into the facts and circumstances of the Thomas Fire. SCE's internal review of the Thomas Fire is complex and examines various matters including possible ignition points, the location of those ignition points, fire progression and the attribution of damages to fires with separate ignition points. As its review of the Thomas Fire progresses and the Thomas Fire litigation process continues, SCE expects to obtain and review additional information, materials and physical information that are in the possession of CAL FIRE and other parties, including SCE equipment that has been retained by CAL FIRE. Based on currently available information, SCE believes that the Thomas Fire had at least two separate ignition points, one near Koenigstein Road in the City of Santa Paula and the other somewhere in the Anlauf Canyon area of Ventura County.

With respect to the Koenigstein Road ignition point, witnesses have reported that a fire ignited in the vicinity of an SCE power pole, and SCE believes that its equipment was associated with this ignition. CAL FIRE has removed equipment located in the general vicinity of Koenigstein Road and SCE has not been able to inspect it. SCE is continuing to assess the progression of the fire from the Koenigstein Road ignition point and the extent of damages that may be attributable to that ignition. At this time, based on available information, SCE has not determined whether the ignition in the Anlauf Canyon area involved SCE equipment. CAL FIRE has removed equipment located in the Anlauf Canyon area and SCE has not been able to inspect it.

Edison International and SCE expect to incur a material loss in connection with the Thomas Fire. However, given the uncertainty as to the contributing causes of the Thomas Fire, the complexities associated with multiple ignition points and the potential for separate damages to be attributable to fires ignited at separate ignition points, Edison International and SCE are currently unable to reasonably estimate a range of losses that may be incurred in connection with the Thomas Fire, but anticipate being able to do so when sufficient additional information becomes available. Such additional information is expected to become available from multiple external sources, during the course of litigation, and from SCE's ongoing internal review, including, among other things, information regarding the extent of damages that may be attributable to any ignition determined to have been substantially caused by SCE's equipment, information that may be obtained from the equipment in CAL FIRE's possession and information pertaining to fire progression, suppression activities, alleged damages and insurance claims.

The extent of potential liability for December 2017 Wildfire-related damages depends on a number of factors, including whether SCE substantially caused, or contributed to, the damages and whether parties seeking recovery of damages will be required to show negligence in addition to causation. Certain California courts have previously found utilities to be strictly liable for property damage, regardless of fault, by applying the theory of inverse condemnation when a utility's facilities were determined to be a substantial cause of a wildfire that caused the property damage. The rationale stated by these courts for applying this theory to investor-owned utilities is that property damages resulting from a public improvement, such as the distribution of electricity, can be spread across the larger community that benefited from such improvement. However, in November 2017, the CPUC issued a decision denying SDG&E's request to include in its rates uninsured wildfire-related costs arising from several 2007 fires, finding that SDG&E did not prudently manage and operate its facilities prior to or at the outset of the 2007 wildfires. In July 2018, the CPUC denied both SDG&E's application for rehearing on its cost recovery request and a joint application for rehearing filed by SCE and PG&E limited to the applicability of inverse condemnation principles in the same proceeding. SDG&E has petitioned the California Court of Appeal to review the CPUC's denial of SDG&E's application. SCE has filed an amicus brief in support of SDG&E's position on the applicability of inverse condemnation. The petition, which is being opposed by the CPUC and other parties, remains pending.

When inverse condemnation is held to be applicable to a utility, the utility may be held strictly liable for property damages and associated interest and attorneys' fees. If inverse condemnation is held to be inapplicable to SCE in connection with the December 2017 Wildfires, SCE could be held liable for property damages and associated interest if the property damages were found to have been proximately caused by SCE's alleged negligence. If SCE is found negligent, SCE could also be held liable for, among other things, fire suppression costs, business interruption losses, evacuation costs, medical expenses, and personal injury/wrongful death claims. These potential liabilities, in the aggregate, will be material. Additionally, SCE could potentially be subject to fines for alleged violations of CPUC rules and laws in connection with the December 2017 Wildfires.

SCE is aware of multiple lawsuits filed related to the Thomas Fire naming SCE as a defendant. A number of the lawsuits also name Edison International as a defendant and some of the lawsuits were filed as purported class actions. The lawsuits, which have been filed in the superior courts of Ventura, Santa Barbara and Los Angeles Counties allege, among other things, negligence, inverse condemnation, trespass, private nuisance, and violations of the public utilities and health and safety codes. By order of the Chair of the California Judicial Council, the lawsuits are being coordinated in the Los Angeles Superior Court. On October 4, 2018, the Superior Court denied Edison International's and SCE's challenge to the application of inverse condemnation to SCE. SCE is assessing the availability of potential challenges to this ruling. SCE expects to be the subject of additional lawsuits related to the Thomas Fire. The litigation could take a number of years to be resolved because of the complexity of the matters and number of plaintiffs.

Additionally, in July 2018 and September 2018, two separate derivative lawsuits for breach of fiduciary duties and unjust enrichment were filed in the Los Angeles Superior Court against certain current and former members of the Boards of Directors of Edison International and SCE (collectively, the "Individual Defendants"). Edison International and SCE are identified as nominal defendants in those actions. The derivative lawsuits generally allege that the Individual Defendants violated their fiduciary duties by causing or allowing SCE to operate in an unsafe manner in violation of relevant regulations, resulting in substantial liability and damage from the December 2017 Wildfires and the Montecito Mudslides.

For events that occurred in 2017, principally the December 2017 Wildfires, SCE has approximately $1 billion of wildfire-specific insurance coverage, subject to a self-insured retention of $10 million per occurrence. Various coverage limitations within the policies that make up SCE's wildfire insurance coverage could result in material self-insured costs in the event of multiple wildfire occurrences during a policy period. Should responsibility for a significant portion of the damages related to the December 2017 Wildfires be attributed to SCE, SCE's insurance may not be sufficient to cover all such damages. In addition, SCE may not be authorized to recover some or all of its uninsured damages through electric service rates if, for example, the CPUC finds that the damages were incurred because SCE did not prudently manage its facilities.

Edison International and SCE are pursuing legislative, regulatory and legal strategies to address the application of a strict liability standard to wildfire-related damages without the ability to recover resulting damages in rates. In September 2018, California Senate Bill 901 ("SB 901") was signed by the Governor of California. Although SB 901 does not address the strict liability standard imposed by courts in inverse condemnation actions, the bill as enacted introduces a number of considerations the CPUC can apply to determine whether costs are recoverable in rates for wildfires occurring on or after January 1, 2019, including, among other things, the utility's actions, circumstances beyond the utility's control and the impact of extreme climate conditions. SB 901 requires investor-owned utilities to prepare annually, for CPUC approval, wildfire risk mitigation plans, and, compliance with an approved plan is one factor the CPUC can consider in addressing cost recovery. SB 901 also calls for a commission on Catastrophic Wildfire Cost and Recovery to be formed to examine, among other things, the allocation of catastrophic wildfire costs in an equitable manner. Edison International and SCE cannot predict whether or when a comprehensive solution mitigating the significant risk faced by a California investor-owned utility related to wildfires will be achieved.

Current Wildfire Insurance Coverage

SCE has approximately $1 billion of wildfire-specific insurance coverage, subject to a self-insured retention of $10 million per occurrence, for events that may occur during the period June 1, 2018 through May 31, 2019. SCE may obtain additional wildfire insurance for portions of this time period in the future. Various coverage limitations within the policies that make up SCE's wildfire insurance coverage could result in material self-insured costs in the event of multiple wildfire occurrences during a policy period or in the event of an exceptionally large wildfire.

SCE's cost of obtaining wildfire insurance coverage has increased significantly as a result of, among other things, the December 2017 Wildfires. Based on policies currently in effect, SCE anticipates that its wildfire insurance expense, prior to any regulatory deferrals, will total approximately $237 million during 2018. SCE has requested approval from the CPUC for regulatory mechanisms to track and recover wildfire insurance premiums in excess of the amounts that are ultimately approved in the 2018 GRC decision. As of September 30, 2018, SCE has a regulatory asset of $63 million related to wildfire insurance costs and believes that such amounts are probable of recovery.

Montecito Mudslides

In January 2018, torrential rains in Santa Barbara County produced mudslides and flooding in Montecito and surrounding areas (the "Montecito Mudslides"). According to Santa Barbara County initial reports, the Montecito Mudslides destroyed an estimated 135 structures, damaged an estimated 324 structures, and resulted in at least 21 fatalities, with two additional fatalities presumed.

Of the lawsuits mentioned above, several allege that SCE has responsibility for the Thomas Fire and that the Thomas Fire proximately caused the Montecito Mudslides, resulting in the plaintiffs' claimed damages. Some of the Montecito Mudslides lawsuits also name Edison International as a defendant. In addition to other causes of action, some of the Montecito Mudslides lawsuits also allege personal injury and wrongful death. By order of the Chair of the California Judicial Council, the Thomas Fire and Montecito Mudslides lawsuits are being coordinated in the Los Angeles Superior Court. SCE expects that additional lawsuits related to the Montecito Mudslides will be filed.

The inquiry into whether the Thomas Fire proximately caused or contributed to the Montecito Mudslides, the source of ignition of the portion of the Thomas fire that burned through the Montecito area and other factors that contributed to the Montecito Mudslides is complex and time consuming. Many other factors, including, among other things, weather conditions and insufficiently or improperly designed and maintained roads, bridges and other channel crossings, could have contributed to or exacerbated the losses that resulted from the Montecito Mudslides. While SCE is not aware of any governmental agency that is investigating the causes of the Montecito Mudslides, SCE is conducting its own review of the factors that potentially contributed to the losses that resulted from the Montecito Mudslides.

At this time, based on available information, SCE has not been able to determine the source of ignition of the portion of the Thomas fire that burned through the Montecito area. In the event that SCE is determined to have caused the fire that spread to the Montecito area, SCE cannot predict whether the courts will conclude that the Montecito Mudslides were caused or contributed to by the Thomas Fire or that SCE is liable for damages caused by the Montecito Mudslides. As a result, Edison International and SCE are currently unable to predict the outcome of the claims made against SCE and Edison International arising from the Montecito Mudslides or reasonably estimate a range of losses that may be incurred. If it is determined that SCE is liable for damages caused by the Montecito Mudslides, SCE will incur a material loss. SCE's insurance coverage for such losses may be limited to its wildfire insurance. In January 2018, SCE also had other general liability insurance coverage of approximately $450 million, but it is uncertain whether these other policies would apply to liabilities alleged to be related to the Montecito Mudslides. Additionally, if SCE is determined to be liable for a significant portion of costs associated with the Montecito Mudslides, SCE's insurance may not be sufficient to cover all such damages. In addition, SCE may not be authorized to recover some or all its uninsured damages through electric service rates if, for example, the CPUC finds that the damages were incurred because SCE did not prudently manage its facilities.

If it is ultimately determined that SCE is legally responsible for damages caused by the Montecito Mudslides and inverse condemnation is held to be applicable to SCE with respect to such damages, SCE may be held liable for resulting property damages and associated interest and attorneys' fees. If inverse condemnation is held to be inapplicable to SCE in connection with the Montecito Mudslides, SCE could be held liable for property damages and associated interest if the property damages were found to have been proximately caused by SCE's alleged negligence. If SCE is found negligent, SCE could also be held liable for, among other things, business interruption losses, evacuation costs, clean-up costs, medical expenses and personal injury/wrongful death claims associated with the Montecito Mudslides. These potential liabilities, in the aggregate, will be material. SCE cannot predict whether it will be subjected to regulatory fines related to the Montecito Mudslides.

Permanent Retirement of San Onofre

Replacement steam generators were installed at San Onofre in 2010 and 2011. On January 31, 2012, a leak suddenly occurred in one of the heat transfer tubes in San Onofre's Unit 3 steam generators. The Unit was safely taken off-line and subsequent inspections revealed excessive tube wear. Unit 2 was off-line for a planned outage when areas of unexpected tube wear were also discovered. On June 6, 2013, SCE decided to permanently retire Units 2 and 3.

San Onofre CPUC Proceeding

On January 30, 2018, SCE, SDG&E, The Alliance for Nuclear Responsibility, The California Large Energy Consumers Association, California State University, Citizens Oversight dba Coalition to Decommission San Onofre, the Coalition of California Utility Employees, the Direct Access Customer Coalition, Ruth Henricks, the CPUC's Public Advocates Office, The Utility Reform Network, and Women's Energy Matters (the "OII Parties") entered into a Revised San Onofre Settlement Agreement (the "Revised San Onofre Settlement Agreement") to resolve the CPUC's investigation regarding the steam generator replacement project at San Onofre and the related outages and subsequent shutdown of San Onofre in the San Onofre Order Instituting Investigation ("OII") proceeding.

In July 2018, the CPUC approved all of the terms of the Revised San Onofre Settlement Agreement other than a provision under which SCE agreed to fund $10 million for a research, development and demonstration program intended to develop technologies and methodologies to reduce greenhouse gas emissions (the "Modification"). The Revised San Onofre Settlement Agreement with the Modification became effective on August 2, 2018. All issues under consideration in the San Onofre OII have been resolved.

Disallowances, Refunds and Recoveries

SCE and SDG&E (the "Utilities") agreed in the Revised San Onofre Settlement Agreement to cease rate recovery of San Onofre costs once their combined remaining San Onofre regulatory assets equal $775 million. The CPUC granted SCE's request to reduce the San Onofre regulatory asset by applying approximately $72 million of proceeds received from litigation with the DOE related to DOE's failure to meet its obligation to begin accepting spent nuclear fuel from San Onofre. As a result, the combined San Onofre regulatory asset balance for the Utilities reached $775 million on December 19, 2017 and SCE ceased recovery of San Onofre costs in rates beginning on December 20, 2017. SCE has refunded to customers approximately $155 million of San Onofre-related amounts recovered in rates on and after December 20, 2017. SCE will retain amounts collected under the Prior San Onofre Settlement Agreement before December 20, 2017. SCE will also retain $47 million of proceeds received in 2017 from arbitration with MHI over MHI's delivery of faulty steam generators. See Note 11 for additional information.

In the Revised San Onofre Settlement Agreement, SCE retains the right to sell its stock of nuclear fuel and not share such proceeds with customers. SCE intends to sell its nuclear fuel inventory as market conditions warrant. Proceeds from sales of nuclear fuel may be significant.

The Revised San Onofre Settlement Agreement also provides for certain exclusions from the determination of SCE's ratemaking capital structure. Notwithstanding that SCE will no longer recover its San Onofre regulatory asset, the debt borrowed to finance the regulatory asset will continue to be excluded from SCE's ratemaking capital structure. Additionally, SCE may exclude the after-tax charge resulting from the implementation of the Revised San Onofre Settlement Agreement from its ratemaking capital structure.

Additional Challenges related to the Settlement of San Onofre CPUC OII Proceeding

A federal lawsuit challenging the CPUC's authority to permit rate recovery of San Onofre costs and an application to the CPUC for rehearing of its decision approving a November 2014 settlement agreement in the San Onofre OII were filed in November and December 2014, respectively. In April 2015, the federal lawsuit was dismissed with prejudice and the plaintiffs in that case appealed the dismissal to the Ninth Circuit Court of Appeals in May 2015. On September 10, 2018, as part of the Revised San Onofre Settlement Agreement, the plaintiffs filed a motion with the Ninth Circuit to dismiss this case with prejudice. The CPUC is opposing the motion. The Ninth Circuit has not yet ruled on the plaintiff's motion to dismiss.

In July 2015, a purported securities class action lawsuit was filed in federal court against Edison International, its then Chief Executive Officer and its then Chief Financial Officer. The complaint was later amended to include SCE's former President as a defendant. The lawsuit alleges that the defendants violated the securities laws by failing to disclose that Edison International had ex parte contacts with CPUC decision-makers regarding the San Onofre OII that were either unreported or more extensive than initially reported. The complaint covers a class of persons who acquired Edison International common stock between March 21, 2014 and August 10, 2015. In September 2016, the federal court granted defendants' motion to dismiss the complaint, with an opportunity for plaintiff to amend the complaint. Plaintiff filed a second amended complaint in October 2016, which the federal court dismissed again with an opportunity for the plaintiff to amend the complaint. Plaintiff filed a third amended complaint in May 2017. In March 2018, the federal court dismissed the third amended complaint with prejudice and entered judgment in defendants' favor. Plaintiff has appealed the dismissal.

In November 2015, a purported class action lawsuit was filed in federal court against Edison International, its then Chief Executive Officer and its Treasurer by an Edison International employee, alleging claims under the Employee Retirement Income Security Act. The complaint purports to be filed on behalf of a class of Edison International employees who were participants in the Edison 401(k) Savings Plan and invested in the Edison International Stock Fund between March 27, 2014 and June 24, 2015. The complaint alleges that defendants breached their fiduciary duties because they knew or should have known that investment in the Edison International Stock Fund was imprudent because the price of Edison International common stock was artificially inflated due to Edison International's alleged failure to disclose certain ex parte communications with CPUC decision-makers related to the San Onofre OII. In July 2016, the federal court granted the defendants' motion to dismiss the lawsuit with an opportunity for the plaintiff to amend her complaint. Plaintiff filed an amended complaint in July 2016, which dismissed Edison International as a named defendant and the remaining defendants filed a motion to dismiss in August 2016. In June 2017, the federal court again granted defendants' motion to dismiss the lawsuit with an opportunity for the plaintiff to amend her complaint. Plaintiff filed another amended complaint in July 2017. Defendants filed a motion to dismiss the amended complaint and, in May 2018, the federal court again granted defendants' motion to dismiss the lawsuit with an opportunity for the plaintiff to amend her complaint. Plaintiff elected not to amend her complaint and the federal court granted judgment in favor of the defendants in August 2018. Plaintiff has appealed the judgment.

Edison International and SCE cannot predict the outcome of these proceedings.

Environmental Remediation

SCE records its environmental remediation liabilities when site assessments and/or remedial actions are probable and a range of reasonably likely cleanup costs can be estimated. SCE reviews its sites and measures the liability quarterly, by assessing a range of reasonably likely costs for each identified site using currently available information, including existing technology, presently enacted laws and regulations, experience gained at similar sites, and the probable level of involvement and financial condition of other potentially responsible parties. These estimates include costs for site investigations, remediation, operation and maintenance, monitoring, and site closure. Unless there is a single probable amount, SCE records the lower end of this reasonably likely range of costs (reflected in "Other long-term liabilities") at undiscounted amounts as timing of cash flows is uncertain.

At September 30, 2018, SCE's recorded estimated minimum liability to remediate its 21 identified material sites (sites with a liability balance at September 30, 2018, in which the upper end of the range of the costs is at least $1 million) was $136 million, including $90 million related to San Onofre. In addition to these sites, SCE also has 15 immaterial sites with a liability balance as of September 30, 2018, for which the total minimum recorded liability was $4 million. Of the $140 million total environmental remediation liability for SCE, $135 million has been recorded as a regulatory asset. SCE expects to recover $43 million through an incentive mechanism that allows SCE to recover 90% of its environmental remediation costs at certain sites (SCE may request to include additional sites) and $92 million through a mechanism that allows SCE to recover 100% of the costs incurred at certain sites through customer rates. SCE's identified sites include several sites for which there is a lack of currently available information, including the nature and magnitude of contamination, and the extent, if any, that SCE may be held responsible for contributing to any costs incurred for remediating these sites. Thus, no reasonable estimate of cleanup costs can be made for these sites.

The ultimate costs to clean up SCE's identified sites may vary from its recorded liability due to numerous uncertainties inherent in the estimation process, such as: the extent and nature of contamination; the scarcity of reliable data for identified sites; the varying costs of alternative cleanup methods; developments resulting from investigatory studies; the possibility of identifying additional sites; and the time periods over which site remediation is expected to occur. SCE believes that, due to these uncertainties, it is reasonably possible that cleanup costs at the identified material sites and immaterial sites could exceed its recorded liability by up to $138 million and $7 million, respectively. The upper limit of this range of costs was estimated using assumptions least favorable to SCE among a range of reasonably possible outcomes.

SCE expects to clean up and mitigate its identified sites over a period of up to 30 years. Remediation costs for each of the next five years are expected to range from $7 million to $20 million. Costs incurred for the nine months ended September 30, 2018 and 2017 were $7 million and $6 million, respectively.

Based upon the CPUC's regulatory treatment of environmental remediation costs incurred at SCE, SCE believes that costs ultimately recorded will not materially affect its results of operations, financial position, or cash flows. There can be no assurance, however, that future developments, including additional information about existing sites or the identification of new sites, will not require material revisions to estimates.

Nuclear Insurance

SCE is a member of NEIL, a mutual insurance company owned by entities with nuclear facilities. NEIL provides insurance for nuclear property damage, including damages caused by acts of terrorism up to specified limits, and for accidental outages for active facilities. The amount of nuclear property damage insurance purchased for San Onofre and Palo Verde exceeds the minimum federal requirement of $50 million and $1.06 billion, respectively. If NEIL losses at any nuclear facility covered by the arrangement were to exceed the accumulated funds for these insurance programs, SCE could be assessed retrospective premium adjustments of up to approximately $52 million per year.

Federal law limits public offsite liability claims for bodily injury and property damage from a nuclear incident to the amount of available financial protection, which is currently approximately $13.1 billion for Palo Verde and $560 million for San Onofre. SCE and other owners of San Onofre and Palo Verde have purchased the maximum private primary insurance available through a Facility Form issued by American Nuclear Insurers ("ANI"). SCE withdrew from participation in the secondary insurance pool for San Onofre for offsite liability insurance effective January 5, 2018. Based on its ownership interests in Palo Verde, SCE could be required to pay a maximum of approximately $60 million per nuclear incident for future incidents. However, it would have to pay no more than approximately $9 million per future incident in any one year. SCE could be required to pay a maximum of approximately $255 million per nuclear incident and a maximum of $38 million per year per incident for liabilities arising from events prior to January 5, 2018, although SCE is not aware of any such events.

For more information on nuclear insurance coverage, see Note 11 in the 2017 Form 10-K.

Spent Nuclear Fuel

Under federal law, the DOE is responsible for the selection and construction of a facility for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The DOE has not met its contractual obligation to accept spent nuclear fuel. Extended delays by the DOE have led to the construction of costly alternatives and associated siting and environmental issues. Currently, both San Onofre and Palo Verde have interim storage for spent nuclear fuel on site sufficient for their current license period.

In June 2010, the United States Court of Federal Claims issued a decision granting SCE and the San Onofre co-owners damages of approximately $142 million (SCE share $112 million) to recover costs incurred through December 31, 2005 for the DOE's failure to meet its obligation to begin accepting spent nuclear fuel from San Onofre. SCE received payment from the federal government in the amount of the damage award. In April 2016, SCE, as operating agent, settled a lawsuit on behalf of the San Onofre owners against the DOE for $162 million (SCE share $124 million, which included reimbursement for approximately $2 million in legal and other costs), to compensate for damages caused by the DOE's failure to meet its obligation to begin accepting spent nuclear fuel for the period from January 1, 2006 to December 31, 2013. In August 2018, the CPUC approved SCE's proposal to return the SCE share of the award to customers based on the amount that customers actually contributed for fuel storage costs; resulting in approximately $105.6 million of the SCE share being returned to customers and the remaining $16.6 million being returned to shareholders. Of the $105.6 million, $71.6 million was applied against the remaining San Onofre Regulatory Asset in accordance with the Revised San Onofre Settlement Agreement. See Note 11 for further information.

The April 2016 settlement also provided for a claim submission/audit process for expenses incurred from 2014 – 2016, where SCE may submit a claim for damages caused by the DOE failure to accept spent nuclear fuel each year, followed by a government audit and payment of the claim. This process made additional legal action to recover damages incurred in 2014 –2016 unnecessary. The first such claim covering damages for 2014 – 2015 was filed on September 30, 2016 for approximately $56 million. In February 2017, the DOE reviewed the 2014 – 2015 claim submission and reduced the original request to approximately $43 million (SCE share was approximately $34 million). SCE accepted the DOE's determination, and the government paid the 2014 – 2015 claim under the terms of the settlement. In October 2017, SCE filed a claim covering damages for 2016 for approximately $58 million. In May 2018, the DOE approved reimbursement of approximately $45 million (SCE share was approximately $35 million) of SCE's 2016 damages, not allowing recovery of approximately $13 million. SCE accepted the DOE's determination, and the government paid the 2016 claim under the terms of the settlement. The damages awards are subject to CPUC review as to how the amounts will be refunded among customers, shareholders, or to offset other costs.