§73.77. Cyber security event notifications.
10 C.F.R. § 73.77
Each licensee subject to the provisions of § 73.54 or § 73.110 shall notify the NRC Headquarters Operations Center via the Emergency Notification System (ENS), under paragraph (c) of this section:
Within one hour after discovery of a cyberattack that adversely impacted—
Safety-related or important-to-safety functions, security functions, or emergency preparedness functions (including offsite communications); or that compromised support systems and equipment resulting in adverse impacts to safety, security, or emergency preparedness functions within the scope of § 73.54; or,
Safety, security, and emergency preparedness functions performed by digital assets that prevent a postulated fission product release resulting in offsite doses exceeding the values in § 53.210 of this chapter, or security functions performed by digital assets necessary for implementing the physical security requirements in § 53.860(a) of this chapter.
Within 4 hours—
After discovery of a cyberattack that could have caused an adverse impact to—
Safety-related or important-to-safety functions, security functions, or emergency preparedness functions (including offsite communications); or that could have compromised support systems and equipment, which if compromised, could have adversely impacted safety, security, or emergency preparedness functions within the scope of § 73.54; or,
Safety, security, and emergency preparedness functions performed by digital assets that prevent a postulated fission product release resulting in offsite doses exceeding the values in § 53.210 of this chapter, or security functions performed by digital assets necessary for implementing the physical security requirements in § 53.860(a) of this chapter.
After discovery of a suspected or actual cyberattack initiated by personnel with physical or electronic access to digital computer and communication systems and networks within the scope of § 73.54 or § 73.110.
After notification to a local, State, or other Federal agency (e.g., law enforcement, Federal Bureau of Investigation (FBI), etc.) of an event related to the licensee's implementation of their cybersecurity program for digital computer and communication systems and networks within the scope of § 73.54 or § 73.110 that does not otherwise require a notification under paragraph (a) of this section.
Within 8 hours after receipt or collection of information regarding observed behavior, activities, or statements that may indicate intelligence gathering or pre-operational planning related to a cyberattack against digital computer and communication systems and networks within the scope of § 73.54 or § 73.110.
Twenty-four hour recordable events.
The licensee shall use the site corrective action program to record vulnerabilities, weaknesses, failures and deficiencies in their § 73.54 or § 73.110 cybersecurity program within 24 hours of their discovery.
The licensee shall use the site corrective action program to record notifications made under paragraph (a) of this section within twenty-four hours of their discovery.
Notification process.
Each licensee shall make telephonic notifications required by paragraph (a) of this section to the NRC Headquarters Operations Center via the ENS. If the ENS is inoperative or unavailable, the licensee shall make the notification via a commercial telephone service or other dedicated telephonic system or any other methods that will ensure a report is received by the NRC Headquarters Operations Center within the timeframe. Commercial telephone numbers for the NRC Headquarters Operations Center are specified in appendix A to this part.
Notifications required by this section that contain Safeguards Information may be made to the NRC Headquarters Operations Center without using secure communications systems under the exception in § 73.22(f)(3) for emergency or extraordinary conditions.
Notifications required by this section that contain Safeguards Information and/or classified national security information and/or restricted data must be made to the NRC Headquarters Operations Center using secure communications systems appropriate to the sensitivity/classification level of the message. Licensees making these types of telephonic notifications must contact the NRC Headquarters Operations Center at the commercial numbers specified in appendix A to this part and request a transfer to a secure telephone.
If the licensee's secure communications capability is unavailable (e.g., due to the nature of the security event), the licensee must provide as much information to the NRC as is required by this section, without revealing or discussing any Safeguards Information and/or Classified Information, in order to meet the timeliness requirements of this section. The licensee must also indicate to the NRC that its secure communications capability is unavailable.
Licensees using a non-secure communications capability may be directed by the NRC Emergency Response management to provide classified information to the NRC over the non-secure system, due to the significance of the ongoing security event. In such circumstances, the licensee must document this direction and any information provided to the NRC over a non-secure communications capability in the written security follow-up report required in accordance with paragraph (d) of this section.
For events reported under paragraph (a)(1) of this section, the NRC may request that the licensee maintain an open and continuous communication channel with the NRC Headquarters Operations Center.
Licensees desiring to retract a previous security event report that has been determined to not meet the threshold of a reportable event must telephonically notify the NRC Headquarters Operations Center and indicate the report being retracted and basis for the retraction.
Declaration of emergencies. Notifications made to the NRC for the declaration of an emergency class shall be performed in accordance with § 50.72 or § 53.1630 of this chapter, as applicable.
Elimination of duplication. Separate notifications and reports are not required for events that are also reportable under §§ 50.72 and 50.73 or §§ 53.1630 and 53.1640 of this chapter. However, these notifications should also indicate the applicable § 73.77 reporting criteria.
Written security follow-up reports. Each licensee making an initial telephonic notification of security events to the NRC according to the provisions of paragraphs (a)(1), (a)(2)(i), and (a)(2)(ii) of this section must also submit a written security follow-up report to the NRC within 60 days of the telephonic notification in accordance with § 73.4.
Licensees are not required to submit a written security follow-up report following a telephonic notification made under § 73.77(a)(2)(iii) or (a)(3).
Each licensee shall submit to the NRC written security follow-up reports that are of a quality that will permit legible reproduction and processing.
Licensees shall prepare the written security follow-up report on NRC Form 366.
In addition to the addressees specified in § 73.4, the licensee shall also provide one copy of the written security follow-up report addressed to the Director, Office of Nuclear Security and Incident Response, or the Director's designee. Any written security follow-up reports containing classified information shall be transmitted to the NRC Headquarters' classified mailing address as specified in appendix A to this part.
The written security follow-up report must include sufficient information for NRC analysis and evaluation.
Significant supplemental information which becomes available after the initial telephonic notification to the NRC Headquarters Operations Center or after the submission of the written security follow-up report must be telephonically reported to the NRC Headquarters Operations Center under paragraph (c) of this section and also submitted in a revised written security follow-up report (with the revisions indicated) as required under this section.
Errors discovered in a written security follow-up report must be corrected in a revised written security follow-up report with the revision(s) indicated.
The revised written security follow-up report must replace the previous written security follow-up report; the update must be complete and not be limited to only supplementary or revised information.
If the licensee subsequently retracts a telephonic notification made under this section as not meeting the threshold of a reportable event, and has not yet submitted a written security follow-up report then submission of a written security follow-up report is not required.
If the licensee subsequently retracts a telephonic notification made under this section as not meeting the threshold of a reportable event after it has submitted a written security follow-up report required by this paragraph, then the licensee shall submit a revised written security follow-up report in accordance with this paragraph.
Each written security follow-up report submitted containing Safeguards Information or Classified Information must be created, stored, marked, labeled, handled, and transmitted to the NRC according to the requirements of §§ 73.21 and 73.22 or with part 95 of this chapter, as applicable.
Each licensee shall maintain a copy of the written security follow-up report of an event submitted under this section as a record for a period of three years from the date of the report or until the Commission terminates the license for which the records were developed, whichever comes first.
Notes, amendments, and revision history
Amendments
[80 FR 67275, Nov. 2, 2015, as amended at 91 FR 15871, Mar. 30, 2026]
Source
Source: 88 FR 15891, Mar. 14, 2023, unless otherwise noted.
Authority
Authority: Atomic Energy Act of 1954, secs. 53, 147, 149, 161, 161A, 170D, 170E, 170H, 170I, 223, 229, 234, 1701 (42 U.S.C. 2073, 2167, 2169, 2201, 2201a, 2210d, 2210e, 2210h, 2210i, 2273, 2278a, 2282, 2297f); Energy Reorganization Act of 1974, secs. 201, 202 (42 U.S.C. 5841, 5842); Nuclear Waste Policy Act of 1982, secs. 135, 141 (42 U.S.C. 10155, 10161); 44 U.S.C. 3504 note. Section 73.37(b)(2) also issued under Sec. 301, Public Law 96-295, 94 Stat. 789 (42 U.S.C. 5841 note).
Source
Source: 38 FR 35430, Dec. 28, 1973, unless otherwise noted.
Amendments
[80 FR 67275, Nov. 2, 2015, as amended at 91 FR 15871, Mar. 30, 2026]