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Commitments and Contingencies - Narrative (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 USD ($) assessment case | Jun. 19, 2019 facility
Loss Contingencies [Line Items] |  |
Nuclear insurance liability limit per incident | $ 13,800 |
Required nuclear liability insurance | 450 |
Nuclear financial protection pool mandated by the Price-Anderson Act | 13,300 |
Maximum assessment mandated by Price-Anderson Act per nuclear reactor for a nuclear incident | $ 138 |
Maximum assessment, administrative fee (as percent) | 5.00% |
Maximum assessment payment mandated by Price-Anderson Act for a nuclear incident | $ 21 |
Maximum assessment | 44.00% |
Nuclear operator maximum annual assessment | $ 9 |
Maximum liability per nuclear incident | 61 |
Mutual property insurance additional blanket policy property coverage | 1,300 |
Nuclear property insurance coverage limit per individual insured | 1,500 |
Lost revenue insurance maximum weekly recovery | 3 |
Accidental outage weekly recovery limit for loss revenues from a nuclear industry mutual insurance company in the event of insurable loss | $ 2 |
The number of months a nuclear industry mutual insurance company will respond to retrospective premium adjustments | 24 months |
Number of years board of directors of industry mutual insurance company can adjust policy after policy expires | 6 years |
Sierra Club Et Al V. Midwest Generation L L C |  |
Loss Contingencies [Line Items] |  |
Number of facilities | facility |  | 4
XOOM Energy Litigation |  |
Loss Contingencies [Line Items] |  |
Number of class action lawsuits | case | 2 |
High |  |
Loss Contingencies [Line Items] |  |
Multiplier that the industry mutual insurance company may assess against insureds premium | assessment | 10 |
Low |  |
Loss Contingencies [Line Items] |  |
Multiplier that the industry mutual insurance company may assess against insureds premium | assessment | 6 |
Nuclear Event |  |
Loss Contingencies [Line Items] |  |
Total nuclear property insurance coverage | $ 2,800 |
Lost revenue insurance maximum weekly recovery | 274 |
Accidental outage weekly recovery limit for loss revenues from a nuclear industry mutual insurance company in the event of insurable loss | 216 |
Non-nuclear Event |  |
Loss Contingencies [Line Items] |  |
Total nuclear property insurance coverage | 1,000 |
Lost revenue insurance maximum weekly recovery | 184 |
Accidental outage weekly recovery limit for loss revenues from a nuclear industry mutual insurance company in the event of insurable loss | $ 144 |

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- Definition This represents the additional policy for weekly lost revenues insured by a nuclear industry mutual insurance company. + References No definition available. + Details
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- Definition NRG’s percentage of ownership in STP. + References No definition available. + Details
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- Definition The industry mutual insurance company may assess the company: 10 times the amount of the total annual premium. + References No definition available. + Details
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- Definition This represents the maximum total weekly recovery for lost revenues insured by a nuclear industry mutual insurance company. + References No definition available. + Details
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- Definition Additional property insurance coverage under a single limit blanket policy purchased from an industry mutual insurance company in order to insure property beyond the individual maximum coverage limit per insured. + References No definition available. + Details
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- Definition Maximum coverage limit per individual insured for property insurance from an industry mutual insurance company. + References No definition available. + Details
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- Definition Total coverage for property insurance from an industry mutual insurance company. + References No definition available. + Details
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- Definition Nuclear Insurance Financial Protection Pool, Maximum Annual Assessment + References No definition available. + Details
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- Definition Maximum assessment to be paid per nuclear reactor for a nuclear incident under the financial protection pool mandated by the Price-Anderson Act. This assessment is paid by each United State nuclear reactor operator over multiple years at a limited amount per year in the event of an incident at any US nuclear reactor. + References No definition available. + Details
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- Definition Nuclear Insurance Financial Protection Pool, Maximum Assessment, Administrative Fee, As a Percent + References No definition available. + Details
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- Definition Nuclear Insurance Financial Protection Pool Nuclear Operator Maximum Annual Assessment + References No definition available. + Details
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- Definition Maximum total assessment to be paid by a nuclear reactor for a nuclear incident under the financial protection pool mandated by the Price-Anderson Act. The total amount is calculated by multiplying the maximum assessment per nuclear reactor, by NRG’s ownership percentage. + References No definition available. + Details
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- Definition Nuclear Insurance Financial Protection Pool Value + References No definition available. + Details
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- Definition This represents the number of years after the policy expires that the industry mutual insurance company’s board of directors can make premium adjustments. + References No definition available. + Details
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- Definition This represents number of months a nuclear industry mutual insurance company will respond to retrospective premium adjustments for policy purchased by company to guarantee financial obligations. + References No definition available. + Details
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