MD 8.3, NRC Incident Investigation Program

NRC Incident Investigation Program

• https://www.nrc.gov/docs/ML2229/ML22294A067.pdf

• Previoushttps://www.nrc.gov/docs/ML1807/ML18073A200.pdf

• issue date: May 4, 2023

See also: Category:MD 8.3 Reactive Inspection Evaluation

Text

U.S. NUCLEAR REGULATORY COMMISSION MANAGEMENT DIRECTIVE (MD)

For updates or revisions to policies contained in this MD that were issued after the MD was signed,

please see the Yellow Announcement to Management Directive index (YA-to-MD index).

MD 8.3 NRC INCIDENT INVESTIGATION

PROGRAM

DT-23-06

Volume 8: Licensee Oversight Programs

Approved By: Scott Morris, Deputy Executive Director for Reactors and Preparedness

Programs, Office of the Executive Director for Operations

Date Approved: May 4, 2023

Cert. Date: N/A, for the latest version of any NRC directive or handbook,

see the online MD Catalog.

Issuing Office: Office of Nuclear Security and Incident Response

Division of Preparedness and Response

Contact Name: Anthony Ulses

EXECUTIVE SUMMARY

Management Directive (MD) 8.3, “NRC Incident Investigation Program,” is revised to—

• Clarify when the staff should recommend to the Commission that an accident

investigation be considered under MD 8.9, “Accident Investigation,” in addition to, or

instead of, an incident investigation under MD 8.3.

• Reflect the current U.S. Nuclear Regulatory Commission organization (i.e., the

restructuring of the Office of Nuclear Material Safety and Safeguards and the Office of

Nuclear Reactor Regulation).

POLICY

It is the policy of the U.S. Nuclear Regulatory Commission (NRC) to ensure that significant

events involving reactor and materials facilities licensed by the NRC are investigated in a

timely, objective, systematic, and technically sound manner; that the factual information

pertaining to each event is documented; and that the cause or causes of each event are

ascertained. The events may involve reactive inspection responses by an incident

investigation team (IIT), augmented inspection team (AIT), or special inspection (SI). (See

Directive Handbook 8.3,Section I.D.1 for the definition of a significant event.1

)

OBJECTIVES

— Promote public health and safety, instill public confidence, and provide for the common

defense and security by reducing the frequency of incidents and preventing accidents.

— Increase the efficiency and effectiveness of NRC regulatory programs and licensee

operations by the prompt dissemination of the facts, conditions, circumstances, and

causes of significant events and the identification of appropriate follow-up actions.

---

1 A significant event is any radiological, safeguards, security, or other event at an NRC-licensed

facility that poses an actual or potential hazard to public health and safety, common defense and

security, property, or the environment.

MD 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

For the latest version of any NRC directive or handbook, see the online MD Catalog. 3

— Improve regulatory oversight of licensee activities by uncovering facts that may indicate

a need to reevaluate whether an aspect of the regulatory process before the event

contributed directly to the cause or course of the event.

— Ensure that IIT, AIT, and SI findings are identified for proper disposition.

ORGANIZATIONAL RESPONSIBILITIES AND DELEGATIONS OF AUTHORITY

A. Commission

Approves the follow-up actions assigned as a result of IIT investigations.

B. Executive Director for Operations (EDO)

1. Approves an IIT investigation of a significant event and ensures that follow-up

actions are taken, as defined in Sections II and III of the directive handbook.

2. Determines whether a potentially significant event is to be investigated by an IIT and

when to recommend to the Commission that an event meets the criteria in

Management Directive (MD) 8.9, “Accident Investigation,” for the formation of an

independent Accident Review Group (ARG) rather than, or in addition to, an IIT.

3. Selects the IIT leader and members, provides policy and technical direction, and

ensures the independence of the IIT.

4. Concurs with the decision, made by the appropriate regional administrator (RA) and

office director following an event that involves an IIT response that facility operations

may resume.

5. Resolves conflicts between a regional office and/or one or more program offices

regarding such matters as the need to initiate an SI, AIT, or IIT.

6. Ensures agency decision-making is appropriately risk-informed, as defined in

NUREG‑2122, “Glossary of Risk-Related Terms in Support of Risk-Informed

Decisionmaking.”

7. Assesses the effectiveness of an IIT investigation and whether it was consistent with

the goals of the incident investigation program.

8. Monitors the closure of IIT findings (i.e., staff actions) of the assigned NRC office

using the Executive Director for Operations (EDO) system of tracking and reporting

and evaluates the staff’s actions to confirm that pertinent aspects of each IIT finding

are addressed in the implemented resolution.

C. Office of the General Counsel (OGC)

1. Provides legal assistance in implementing the NRC incident investigation program.

2. Provides legal staff to support IITs.

For the latest version of any NRC directive or handbook, see the online MD Catalog. 4

D. Office of the Inspector General (OIG)

Participates as an observer during IITs and AITs in coordination with the Director of the

Office of Nuclear Security and Incident Response (NSIR).

E. Atomic Safety and Licensing Board Panel (ASLBP)

Provides professional stenographers to transcribe formal interviews conducted by the

IIT.

F. Director, Office of Congressional Affairs (OCA)

Makes congressional notifications and arranges congressional briefings, as appropriate,

to ensure Congress is informed of NRC responses to events.

G. Director, Office of Public Affairs (OPA)

1. Follows established NRC public affairs policies for keeping the media and the public

informed of information related to NRC investigatory responses to events (see

Section II of the directive handbook).

2. Supports IITs.

3. Reviews the scenario(s) to determine the importance of issuing news releases and

social media communications announcing the formation of applicable AITs, IITs, and

SIs on a case-by-case basis, as appropriate; and arranges for media briefings.

Informs and, as applicable, educates the public of AIT exit meetings, IIT status

briefings, and meetings regarding the final investigation results.

H. Director, Office of Nuclear Security and Incident Response (NSIR)

1. With the assistance of other NRC offices, and in consideration of the Office of

Nuclear Security and Incident Response’s (NSIR’s) independent role as lead for the

agency’s Incident Response Program, administers the incident investigation program

to meet the objectives set forth in this MD.

2. Establishes and maintains an NRC investigatory capability and identifies and

coordinates training requirements for IIT candidates through the Technical Training

Center (TTC).

3. Establishes and maintains rosters of potential IIT team leaders and team members

who are certified through formal training in incident investigation.

4. Ensures that procedures governing IITs are developed, coordinated, approved,

distributed, and maintained.

5. Ensures the agency decision-making regarding reactive inspections is appropriately

risk-informed and provides independent review of the agency’s incident investigation

activities, as needed.

For the latest version of any NRC directive or handbook, see the online MD Catalog. 5

6. Provides administrative support staff to IITs (and, as requested, for AITs), as

necessary, to achieve objectives defined in Section II of the directive handbook, with

assistance from other NRC offices. This may include security experts in the case of

security issues.

7. For events warranting consideration of an AIT or an IIT, consults with the appropriate

RA and the Director of the Office of Nuclear Reactor Regulation (NRR) (power

reactor or non-power utilization facilities (NPUF) events), or the Director of the Office

of Nuclear Material Safety and Safeguards (NMSS) (fuel facility or materials events)

on the decision. Identifies the potential security or safeguards issues and provides

recommendations to the EDO on events warranting consideration of an IIT and on

the composition of the IIT.

8. Assesses the effectiveness of incident investigation program activities and

recommends action, as appropriate, to improve the program.

9. Provides advice and assistance on the conduct of the agency’s incident investigation

activities, including on the protection of classified or Controlled Unclassified

Information (CUI) related to the incident.

10. Provides advice and consultation to the IIT leader on procedural matters and

suggestions regarding completeness of the IIT report.

11. Coordinates with the Office of Administration (ADM) to provide support necessary to

publish an IIT report as a NUREG document.

I. Director, Office of Nuclear Reactor Regulation (NRR)

1. Ensures that event procedures governing AITs and SIs for power reactors, NPUF,

and vendor facilities are defined, developed, coordinated, approved, distributed, and

maintained.

2. Identifies and provides staff to be members and leaders of IITs, AITs, and SIs, as

needed.

3. Provides assistance in implementing the incident investigation program.

4. For power reactor events warranting consideration of an IIT or AIT, consults with the

appropriate RA and the Director of NSIR on the decision.

5. For NPUF and vendor facilities, coordinates with the appropriate RA and the Director

of NSIR on events warranting consideration of an IIT or AIT. Determines whether an

SI is warranted at NPUF and vendor facilities. Notifies the appropriate RA, the

Director of NSIR, and the EDO when initiating an AIT or SI led out of NRR. When

conflicts exist between a regional office and/or one or more program offices

regarding the decision to initiate an SI, AIT, or IIT, the EDO shall make the decision.

For the latest version of any NRC directive or handbook, see the online MD Catalog. 6

6. Selects the SI and AIT leader and team members, as appropriate, and directs,

coordinates, and monitors the performance of SIs and AITs led out of NRR.

7. Identifies the potential public health and safety or safeguards issues and provides

recommendations to the EDO on events warranting consideration of an IIT and on

the composition of the IIT.

8. Provides and coordinates risk analysis support to the regions for events that warrant

an IIT or AIT consideration or when requested by the appropriate RA.

9. Discusses with the appropriate RA and the Director of NSIR the acceptability of the

licensee’s decision to resume facility operations following an IIT response and

event-related shutdown. Obtains the EDO’s concurrence for resumption of

operations.

10. Ensures that office decision-making is appropriately risk-informed.

J. Director, Office of Nuclear Regulatory Research (RES)

1. Provides staff as members and leaders of IITs, AITs, and SIs, as needed.

2. Provides assistance in implementing the NRC incident investigation program.

3. Provides risk analysis support (coordinated by NRR) to the regions for power reactor

events that warrant an IIT or AIT consideration or when requested by the appropriate

RA.

4. Assists in identifying potential nuclear material safety, health, or safeguards issues.

K. Director, Office of Nuclear Material Safety and Safeguards (NMSS)

1. Ensures that procedures governing SIs and AITs for fuel cycle facility, waste

disposal, spent nuclear fuel storage facility, nuclear and radioactive material, and

material transportation events are defined, developed, coordinated, approved,

distributed, and maintained.

2. Identifies and provides staff as members and leaders of IITs, AITs, and SIs, as

needed.

3. Provides assistance in implementing the NRC incident investigation program.

4. For fuel cycle facility, waste disposal, spent nuclear fuel storage facility, nuclear and

radioactive material, and material transportation events warranting consideration of

an IIT or AIT, consults with the appropriate RA and the Director of NSIR on the

decision.

5. Notifies the appropriate RA, the Director of NSIR, and the EDO when initiating an SI

led out of NMSS. When conflicts exist between a regional office and/or one or more

MD 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

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program offices regarding the decision to initiate an SI or IIT, the EDO shall make the

decision.

6. Selects the SI or AIT leader and members, as appropriate, and directs, coordinates,

and monitors the performance of SIs or AITs led out of NMSS.

7. Identifies the potential public health and safety or safeguards issues and provides

recommendations to the EDO and the Director of NSIR on events warranting

consideration of an IIT, including the composition of the IIT.

8. Discusses with the appropriate RA and obtains the EDO's concurrence on the

acceptability of the decision by the affected licensee to resume facility operations

following an event that involves an IIT response where the facility has been shut

down.

9. Ensures that office decision-making is appropriately risk-informed.

L. Director, Office of Investigations (OI)

1. Provides assistance in implementing the incident investigation program.

2. Provides staff members in support of IIT, AIT, and SI objectives.

3. Shares with the appropriate region and headquarters offices information obtained in

connection with any parallel OI investigation that indicates significant increases in the

health, safety, or security significance of the event.

M. Chief Human Capital Officer (CHCO)

1. Assists with IIT training on an as needed basis.

2. Coordinates and assists with IIT training development and delivery following

established agency training policies and procedures.

N. Regional Administrators

1. Identify and provide staff to be members and leaders of IITs, AITs, and SIs as

needed.

2. Provide assistance in implementing the NRC incident investigation program.

3. Coordinate with the Directors of NRR or NMSS, as appropriate, and the Director of

NSIR on events that warrant consideration of an IIT or AIT.

4. For SIs and AITs led out of the region (e.g., power reactors, fuel cycle facilities),

determine whether an SI or AIT is warranted. Notify the appropriate Director of NRR

or NMSS, the Director of NSIR, and the EDO when initiating an SI or AIT led out of

the region. When conflicts exist between a regional office and/or one or more

program offices regarding the decision to initiate an SI, AIT, or IIT, the EDO shall

make the decision.

For the latest version of any NRC directive or handbook, see the online MD Catalog. 8

5. Select the SI or AIT leader and members, as appropriate and direct, coordinate, and

monitor the performance of SIs or AITs led out of the region.

6. Identify potential health and safety or safeguards issues and provide

recommendations to the EDO on events warranting consideration of an IIT.

7. Make appropriate notifications to Federally recognized Tribes and States(s) of NRC

responses to events.

8. Issue a confirmatory action letter when significant concerns about health and safety,

safeguards, or the environment exist to establish commitments to ensure the facility

is maintained in a safe condition and to preclude event-related resumptions of

operations without NRC concurrence when appropriate. The confirmatory action

letter may also need to address failed equipment, quarantined areas, agreed-upon

controls for troubleshooting, and data preservation and retrieval to ensure a

complete understanding of the event’s causes and timeline.

9. Consult with the appropriate office director(s) and the Director of NSIR on the

acceptability of the licensee’s decision to resume facility operations following an IIT

response and event-related shut down. Obtain the EDO’s concurrence for

resumption of operations.

10. Ensure that regional decision-making is appropriately risk-informed.

11. Provide assistance in briefing and supplying background information to the IIT when

it arrives on site. Provide onsite support for the IIT during its investigation.

12. Identify and provide staff to monitor licensee troubleshooting activities to assess

equipment performance.

O. Office Directors

Participate in the incident investigation program as defined in this MD.

APPLICABILITY

The policy and guidance of this directive and handbook apply to all NRC employees and

contractors.

DIRECTIVE HANDBOOK

Directive Handbook 8.3 discusses the major components of the NRC's response to

significant events (i.e., IIT, AIT, and SI).

MD 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

For the latest version of any NRC directive or handbook, see the online MD Catalog. 9

REFERENCES

Code of Federal Regulations

10 CFR Part 20, Appendix B, Table 2, “Effluent Concentrations.”

10 CFR 71.87, “Routine Determinations.”

Nuclear Regulatory Commission Documents

Incident Response Manual Chapter 300, “Incident Investigation” (ML14113A013).

Inspection Manual Chapters (https://www.nrc.gov/reading-rm/doc-collections/inspmanual/manual-chapter/index.html):

0609, “Significance Determination Process.”

1301, “Response to Radioactive Material Incidents That Do Not Require

Activation of the NRC Incident Response Plan.”

1302, “Follow-up Actions and Action Levels for Radiation Exposures Associated

with Materials Incidents Involving Members of the Public.”

Inspection Procedures (https://www.nrc.gov/reading-rm/doc-collections/inspmanual/inspection-procedure/index.html):

71153, “Follow up of Events and Notices of Enforcement Discretion.”

93800, “Augmented Inspection Team.”

93812, “Special Inspection.”

Management Directives (https://www.nrc.gov/reading-rm/doccollections/management-directives/index.html):

8.2, “NRC Incident Response Program.”

8.9, “Accident Investigation.”

8.10, “NRC Assessment Program for a Medical Event or an Incident Occurring at

a Medical Facility.”

NUREG‑2122, “Glossary of Risk-Related Terms in Support of Risk-Informed

Decisionmaking” (https://www.nrc.gov/reading-rm/doccollections/nuregs/staff/sr2122/index.html).

U.S. NUCLEAR REGULATORY COMMISSION DIRECTIVE HANDBOOK (DH)

For updates or revisions to policies contained in this MD that were issued after the MD was signed,

please see the Yellow Announcement to Management Directive index (YA-to-MD index).

DH 8.3 NRC INCIDENT INVESTIGATION

PROGRAM

DT-23-06

Volume 8: Licensee Oversight Programs

Approved By: Scott Morris, Deputy Executive Director for Reactors and Preparedness

Programs, Office of the Executive Director for Operations

Executive Director for Operations

Date Approved: May 4, 2023

Cert. Date: N/A, for the latest version of any NRC directive or handbook,

see the online MD Catalog.

Issuing Office: Office of Nuclear Security and Incident Response

Division of Preparedness and Response

Contact Name: Anthony Ulses

EXECUTIVE SUMMARY

Management Directive (MD) 8.3, “NRC Incident Investigation Program,” is revised to—

• Clarify when the staff should recommend to the Commission that an accident

investigation be considered under MD 8.9, “Accident Investigation,” in addition, to or

instead of, an incident investigation under MD 8.3.

• Reflect the current U.S. Nuclear Regulatory Commission organization (i.e., the

restructuring of the Office of Nuclear Material Safety and Safeguards and the Office of

Nuclear Reactor Regulation).

TABLE OF CONTENTS

I. MAJOR COMPONENTS AND RESPONSIBILITIES OF THE PROGRAM ........................ 2

A. Coverage...................................................................................................................... 2

B. Incident Investigation Team (IIT) .................................................................................. 2

C. Augmented and Special Inspections............................................................................. 2

D. Significant Event Process ............................................................................................. 3

II. INCIDENT INVESTIGATION TEAM................................................................................... 8

A. Objectives of an Incident Investigation Team................................................................ 8

B. Scope of an Incident Investigation ................................................................................ 8

DH 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

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C. Schedule ...................................................................................................................... 9

D. Team Composition and Qualifications .......................................................................... 9

E. Duties of the Incident Investigation Team ...................................................................10

F. Conduct of an Investigation ........................................................................................11

G. Follow Up ...................................................................................................................12

III. AUGMENTED AND SPECIAL INSPECTIONS ................................................................12

A. Objectives of an AIT and an SI team ..........................................................................12

B. Scope of an augmented or special inspection.............................................................12

C. Schedule ....................................................................................................................13

D. Composition and Qualifications ..................................................................................13

E. Follow Up ...................................................................................................................13

I. MAJOR COMPONENTS AND RESPONSIBILITIES OF THE PROGRAM

A. Coverage

“Incident investigation” is a formal process conducted for the purpose of accident

prevention. The process includes gathering and analyzing information; determining

findings and conclusions, including the cause(s) of a significant event; and disseminating

the investigation results for the U.S. Nuclear Regulatory Commission (NRC), industry,

and public review. The components of the process follow.

B. Incident Investigation Team (IIT)

An Incident Investigation Team (IIT) consists of technical experts who, to the extent

possible, do not have, and have not had, previous significant involvement with licensing

and inspection activities at the affected facility and who perform the single NRC

investigation of a significant event as described in Section II of this handbook. An NRC

senior manager leads the IIT. Each IIT reports directly to the Executive Director for

Operations (EDO) and is independent of regional and headquarters office management.

Incident Response Manual Chapter (IRMC) 300, “Incident Investigation”

(ML14113A013), provides implementing guidelines for IITs.

C. Augmented and Special Inspections

An augmented or special inspection is performed by one or more technical experts from

the region where the event took place and may be augmented by personnel from

headquarters, contractors, or other regions, as needed. The inspector(s) may have had

prior involvement with licensing and inspection activities at the affected facility. The

inspector(s) report(s) directly to the appropriate regional administrator (RA) or office

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director when the reactive inspection is led out of headquarters. Inspection Procedure (IP) 93800, “Augmented Inspection Team” (AIT) and IP 93812, “Special Inspection” (SI)

are the implementing procedures for these reactive inspections.

D. Significant Event Process

1. General

(a) A significant event is any radiological, safeguards, security, or other event at an

NRC-licensed facility that poses an actual or potential hazard to public health and

safety, common defense and security, property, or the environment. A significant

operational event also may be referred to as “an incident” (see Management

Directive (MD) 8.2, “NRC Incident Response Program,” for more information).

(b) The decision regarding an “investigatory response” for a significant event is

defined by its risk significance, complexity, and generic safety or security

implications. Significant events at power reactor facilities are evaluated

considering both deterministic criteria and risk significance (e.g., conditional core

damage probability (CCDP)) in order to define the level of investigatory

response. Other significant events (e.g., fuel facility, material, non-power

utilization facilities (NPUF), safeguards, and security events) are evaluated on

the basis of deterministic criteria in order to define the level of investigatory

response.

(c) Significant events may involve responses by an IIT or less formal responses by

an AIT or an SI, depending upon the level of response deemed appropriate. The

level of investigatory response for significant power reactor events is based on

both the deterministic criteria and the risk criteria included in this section. See

Section I.D.2 of this handbook for the criteria for significant events involving

power reactors, NPUFs, fuel cycle, and materials. Consult MD 8.10, “NRC

Assessment Program for a Medical Event or an Incident Occurring at a Medical

Facility,” for detailed criteria for medical events.

(d) Upon notification of a significant power reactor event, the RA and staff should

perform an initial review to assess the safety or security significance of the event

in order to determine the level of response required. The Office of Nuclear

Regulatory Research (RES) will provide risk analysis support (coordinated by the

Office of Nuclear Reactor Regulation (NRR)) to the regions for power reactor

events that warrant at least consideration of an AIT. If requested by the RA, RES

will provide risk analysis support for events for which only consideration of the

need for an SI may be warranted.

(e) If the initial review indicates that the event warrants at least consideration of an

AIT response, the RA shall consult with the Director of the Office of Nuclear

Security and Incident Response (NSIR) and the Director of NRR (power reactor

and NPUF events), or the Director of the Office of Nuclear Material Safety and

DH 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

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Safeguards (NMSS) (fuel facility, material and material transportation events), to

decide if an AIT or an IIT response is appropriate on the basis of their collective

judgment.

(f) Upon notification of a significant event at an NPUF, the Director of NRR and staff

should perform the initial review to assess the safety or security significance of

the event to determine the level of response required.

(g) If the results of the initial review of a significant event at an NPUF conclude that

the event warrants at least consideration of an AIT response, the Director of NRR

shall consult with the Director of NSIR and the appropriate RA to decide if an AIT

or an IIT is the proper response.

(h) If an IIT is agreed upon, the initiating office makes that recommendation to the

EDO. The EDO resolves differences among offices concerning whether an AIT or

an IIT is the proper response.

2. Criteria to Evaluate Level of Response for a Significant Event

(a) Significant Event at a Power Reactor

(i) A power reactor event meeting the following deterministic criteria should be

evaluated for risk to aid in determining the level of response, if any. The event

may include significant unplanned degraded conditions as identified by the

licensee or the NRC.

• Operation that exceeded, or was not included in, the design bases of the

facility.

• Major deficiency in design, construction, or operation having a potential

generic safety implication.

• Significant loss of integrity of the fuel, the primary coolant pressure

boundary, or the primary containment boundary.

• Loss of a safety function or multiple failures in systems used to mitigate

an actual event.

• Possible adverse generic implication.

• Significant unexpected system interaction.

• Repetitive failures or events involving safety-related equipment or

deficiencies in operations.

• Question or concern pertaining to licensee performance.

• Circumstance sufficiently complex, unique, or not well enough

understood, or involving safeguards concerns, or involving characteristics

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the investigation of which would best serve the needs and interests of the

Commission.

(ii) Failure of licensee safety-related equipment or adverse impact on licensee

operations because of a safeguards-initiated event (e.g., tampering).

• Actual intrusion into the protected area.

• Significant loss of safeguards information that could compromise common

defense and security.

(iii) A significant power reactor event meeting the above deterministic criteria

should be evaluated for risk as follows:

• CCDP best reflects loss of defense-in-depth due to the event, regardless

of whether the cause is deficient licensee performance or otherwise.

• CCDP accounts for actual plant configuration, including equipment that is

unavailable because of maintenance and testing.

(iv) Inspection Manual Chapter (IMC) 0609, “Significance Determination

Process,” addresses CCDP determination. Although CCDP represents a

fundamentally different concept for events than for degraded conditions that

do not initiate an event, the same guidelines may be applied to each in

assisting management in its risk-informed decision-making.

(v) The lack of complete event information at the time of the NRC response

decision focuses attention on the uncertainty of influential assumptions and

their effect on the risk significance. IP 71153, “Follow up of Events and

Notices of Enforcement Discretion,” discusses inspector input to risk analyses

that is needed to understand the risk significance. In determining the risk

significance of an event, NRC should assess the potential influence on risk of

the following:

• Dominant core damage sequence(s).

• Level of confidence in failure/unavailability values assumed for the

sequence(s).

• Influence on the CCDP estimate of contributing factors where the

confidence level is low.

(vi) The following table lists appropriate power reactor event response options as

a function of CCDP. The overlap of options relative to CCDP levels provides

the opportunity to select different inspection or investigation options on the

basis of factors like uncertainty of the risk estimate coupled with the

deterministic insights. Risk insights should also be used in considering the

number of inspectors, their expertise, and the areas of focus. In addition to

DH 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

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risk, NRC should assess whether degraded conditions could increase the

likelihood of a large, early release resulting from containment failure.

Estimated CCDP

CCDP < 1E-6 1E-6 –> 1E-5 1E-5 –> 1E-4 1E-4 –> 1E-3 CCDP > 1E-3

No Additional Inspection

SI

AIT

IIT

(b) Significant NPUF, Fuel Facility, or Materials Event

In addition to the above guidance for power reactor events (and guidance found

in IMC 1301, “Response to Radioactive Material Incidents That Do Not Require

Activation of the NRC Incident Response Plan,” and IMC 1302, “Follow-up

Actions and Action Levels for Radiation Exposures Associated with Materials

Incidents Involving Members of the Public”) the following guidance should be

considered for any significant NPUF, fuel cycle, or materials event, including

materials events at power reactors:

(i) An IIT should be considered for a significant event with one or more of the

following characteristics:

• Led to a significant radiological release (levels of radiation or

concentrations of radioactive material in excess of 10 times any

applicable limit in the license or 10 times the concentrations specified in

10 CFR Part 20, Appendix B, Table 2, “Effluent Concentrations,” when

averaged over a year) of byproduct, source, or special nuclear material to

unrestricted areas.

• Led to a significant occupational exposure or significant exposure to a

member of the public. In both cases, “significant” is defined as five times

the applicable regulatory limit (except for shallow-dose equivalent to the

skin or extremities from discrete radioactive particles).

• Led to a site area emergency.

• Exceeded a safety limit of the licensee's technical specifications.

• Involved the medical use of byproduct, source, or special nuclear material

and may have resulted in deterministic effects to a significant number of

patients or individuals over a long period (months or years).

DH 8.3 NRC INCIDENT INVESTIGATION PROGRAM Date Approved: 5/4/2023

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• Involved the medical, academic, or commercial use of byproduct, source,

or special nuclear material and resulted in the potential exposure of a

significant number of individuals above occupational or public dose limits.

• Involved the deliberate misuse of byproduct, source, or special nuclear

material from its intended or authorized use, which resulted in the

exposure of a significant number of individuals.

• Involved byproduct, source, or special nuclear material, which may have

resulted in a fatality.

• Involved circumstances sufficiently complex, unique, or not well enough

understood, or involved safeguards concerns, or involved characteristics

the investigation of which would best serve the needs and interests of the

Commission.

• Actual intrusion into the protected area or controlled access area or the

established first-line physical barrier for controlling personnel access to

the facility.

• Involved a willful disclosure of classified information with potential

damage to national security.

(ii) For an event of lesser health and safety or safeguards significance an AIT

should be formed. The characteristics of this event may include one or more

of the following:

• Led to a radiological release of byproduct, source, or special nuclear

material to unrestricted areas that resulted in occupational exposure or

exposure to a member of the public in excess of the applicable regulatory

limit (except for shallow-dose equivalent to the skin or extremities from

discrete radioactive particles).

• Involved the deliberate misuse of byproduct, source, or special nuclear

material from its intended or authorized use and had the potential to

cause an exposure of greater than 5 rem to an individual or 500 mrem to

an embryo or fetus.

• Involved a significant infraction or repeated instances of safeguards

infractions that demonstrate the ineffectiveness of facility security

provisions.

• Involved repeated instances of inadequate nuclear material control and

accounting provisions to protect against theft or diversions of nuclear

material.

• Involved the failure of the dam for mill tailings with substantial offsite

release of tailings material and solution.

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• Involved the failure of radioactive material packaging that resulted in

external radiation levels exceeding 10 rads/hr or contamination of the

packaging exceeding 1000 times the applicable limits specified in

10 CFR 71.87, “Routine Determinations.”

• Involved a loss of classified or safeguards information with potential

disclosure to unauthorized individuals affecting national security or the

common defense and security.

II. INCIDENT INVESTIGATION TEAM

The investigatory initiative involving a response by an IIT is described in this part.

A. Objectives of an Incident Investigation Team

The objectives of an IIT are to—

1. Conduct a timely, thorough, systematic, formal, and independent investigation of

certain safety-significant or security events occurring at facilities licensed by the

NRC.

2. Collect, analyze, and document factual information and evidence sufficient to

determine the probable cause(s), conditions, and circumstances pertaining to the

event.

B. Scope of an Incident Investigation

1. An IIT investigation should emphasize factfinding and determination of probable

cause for a significant event. The scope of the investigation must be sufficient to

ensure that the event is clearly understood, the relevant facts and circumstances are

identified and collected, and the probable cause(s) and contributing cause(s) are

identified and substantiated by the evidence associated with the event. The

investigation must consider whether licensee and NRC activities preceding and

during the event were timely and adequate.

2. The scope of an IIT investigation must (1) be approved by the EDO and (2) include

conditions preceding the event, event chronology, systems response, human factors

considerations, equipment performance, precursors to the event, emergency

response, safety significance, radiological considerations, security significance, and

findings and conclusions. The scope of the IIT investigation will be established by a

charter attached to the initiating memorandum from the appropriate office director to

the EDO.

3. The scope of the investigation shall exclude—

(a) Specific assessment of violations of NRC rules and requirements;

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(b) Review of the design and licensing bases for the facility, except as necessary to

assess the cause for the event under investigation;

(c) Assessment of reasonable assurance of offsite emergency response capabilities

of Federally recognized Tribes, States(s), and local agencies; and

(d) Determination for resumption of licensed operation.

4. However, the NRC will consider information collected as part of the IIT process when

a decision is made by the affected licensee to resume facility operations before

issuance of the IIT report. These instances require close coordination between the

IIT leader, the RA, the appropriate program office director, and the Director of NSIR.

C. Schedule

1. The IIT must be activated as soon as practicable after the health and safety

significance of the event is determined and will begin its investigation as soon as

practicable after the facility has been placed in a safe, secure, and stable condition. If

there is an NRC incident response, the IIT investigation will begin after the incident

response is deactivated. Refer to IRMC 300 (ML14113A013) for detailed activation

and scheduling guidance.

2. The IIT must issue interim reports at appropriate intervals outlining the status, plans,

and relevant new information related to its investigation.

3. The IIT must prepare and transmit its final report to the Commission and the EDO

within 45 days of activation of the team, unless relief is granted by the EDO. The

EDO will normally schedule a meeting for the IIT to brief the Commission on its

investigation approximately 1 week after receipt of the final report. The final IIT report

will be published as a NUREG.

4. Information contained in the report is not to be released to the public until a copy of

the final report is placed in the Agencywide Documents Access and Management

System (ADAMS), which normally occurs during the day of the Commission briefing,

if one is conducted. Following the Commission briefing, the EDO will transmit a copy

of the final report to the licensee and the NRC staff for review and comment before

the EDO defines the follow-up actions and assigns them to NRC offices. If deemed

necessary, the EDO may forward a copy of the final report to the affected licensee

before the Commission briefing and simultaneously forward a copy of the final report

to ADAMS.

D. Team Composition and Qualifications

1. The IIT will be composed of technical experts selected based on their expertise

relevant to the event under investigation and their freedom from significant

involvement in the licensing and inspection of the facility involved or other activities

associated with issues that had a direct effect on the course or consequences of the

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event. The number of members and areas of technical expertise required for each IIT

will be determined based on the type of facility and characteristics of the event.

2. The special procedures for clearing non-Government individuals, which are outlined

in IRMC 300, apply whenever these individuals are used to support an IIT.

3. The team leader and expert members should, to the extent practicable, be selected

from rosters of candidates who have been certified through formal training in incident

investigation. An NRC senior manager from the Senior Executive Service shall be

the team leader.

E. Duties of the Incident Investigation Team

1. The IIT carries out the single NRC fact finding investigation of the event and is

authorized to pursue and is responsible for pursuing all aspects of an event that are

within its scope as defined above. NRC response personnel on site shall provide

support as needed to ensure the efficient and effective transition to investigation of

the event in a manner that does not interfere with facility safety.

2. IIT Leader

(a) Directs and manages the IIT in its investigation and ensures that the objectives

and schedules are met for the investigation as defined in this handbook.

(b) Identifies, adds, and removes equipment and areas from the quarantined list to

ensure facility safety. In addition, ensures that the licensee is able to perform

appropriate maintenance and testing of equipment and determine causes for

equipment anomalies.

(c) Works with the Office of Public Affairs (OPA) in providing the news media with

information on IIT activities.

(d) Serves as principal spokesperson for IIT activities when interacting with the

licensee, NRC offices, the Advisory Committee on Reactor Safeguards (ACRS),

the Advisory Committee on the Medical Uses of Radioisotopes (ACMUI), news

media, and other organizations on matters involving the investigation.

(e) Prepares frequent status reports documenting IIT activities, plans, significant

findings, and health and safety concerns that may require timely remedial actions

or issuance of information notices, bulletins, or orders.

(f) Receives direction from and supervision by the EDO.

(g) Identifies and requests that the EDO provide additional IIT resources

(e.g., additional members, consultants, contractor assistance), as needed.

(h) Identifies and recommends to the EDO further studies and investigations, for

example, as those involving staff performance in regulatory activities before the

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event, when significant concerns could not be thoroughly evaluated because of

time or resource limitations.

(i) Ensures, in cooperation with the IIT members and the technical writer/editor,

preparation of the final report by the due date established by the EDO.

(j) Briefs the Director of NRR or NMSS, as appropriate, the Director of NSIR, and

the RA on the facts surrounding the event in support of decision-making

concerning resumption of facility operations by the affected licensee.

(k) Promptly documents and conveys significant ancillary findings or information

outside the scope of the IIT charter to regional management for follow-up action.

(l) Ensures that a lessons-learned evaluation is conducted and documented on the

IIT efforts and results.

F. Conduct of an Investigation

1. The investigation process is based on the principles of incident

investigation provided in IIT training programs and described in IRMC 300.

2. The composition of the IIT must be structured and the procedures developed to

maintain independence and objectivity. Personnel possessing a high degree of

independence, ingenuity, and resourcefulness should be selected to ensure that

the investigation is conducted in a timely, professional, thorough, and coordinated

manner.

3. Implementing procedures to guide and control the establishment and investigatory

activities of an IIT are included in IRMC 300. This procedure provides guidance for—

(a) Activating an IIT, including responsibilities, coordination, communication, team

composition, and guidance;

(b) Outlining an IIT investigation of an event, including responsibilities, work plan,

communication, interfaces, scope, and schedule;

(c) Interviewing personnel;

(d) Collecting and maintaining records, documents, data, and other information;

(e) Treating quarantined equipment and areas; and

(f) Preparing the IIT report, reviewing the IIT report for classified or sensitive

unclassified information, and distributing the IIT report and related documents.

4. For an IIT involving a medical event, additional guidance is provided in MD 8.10.

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G. Follow Up

1. Following NRC staff and licensee review and comment on the IIT report, the EDO

identifies generic and facility-specific staff actions that must be taken as a result of

the findings of the investigation. Following Commission approval, the EDO shall

assign an NRC office responsibility for each action. Office directors shall provide a

written status report on the disposition of each assigned action as directed by the

EDO.

2. The memorandum assigning follow-up actions (i.e., staff actions) should address all

IIT findings, including those that are judged to require no follow-up action, to

document the consideration of all findings. The resolution of each staff action will be

documented by the assigned NRC lead office in a single safety evaluation report,

and each staff action will be individually tracked by the EDO's status tracking and

reporting system.

III. AUGMENTED AND SPECIAL INSPECTIONS

A. Objectives of an AIT and an SI team

1. Conduct a timely, thorough, and systematic inspection related to significant events at

facilities licensed by the NRC.

2. Assess the health and safety significance of the event and communicate to regional

and headquarters management the facts and safety or security concerns related to

the event so that appropriate follow-up actions can be taken (e.g., study a generic

concern, issue an information notice or bulletin, or issue a generic communication).

3. Collect, analyze, and document information and evidence sufficient to determine the

cause(s), conditions, and circumstances pertaining to the event.

B. Scope of an augmented or special inspection

AIT inspections and SI are conducted using IP 93800 and IP 93812, respectively. The

scope of inspection is defined by the inspection guidance contained in each IP and the

inspection charter developed for the inspection.

1. The purpose of the charter is to delineate the general scope of the reactive

inspection and to facilitate fact gathering and understanding thorough independent

review. Available risk insights should be used to develop the scope of the charter.

Examples of items the charter can include are conditions preceding the event, event

chronology, system responses, human factors, safety culture, equipment

performance, quality assurance, radiological considerations, safeguard

considerations, event precursors, event response, operating experience, and safety

or security impacts in determining the causes of the significant event and in support

of appropriate agency follow-up actions. The charter should assess any immediate

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corrective actions and compensatory measures taken to address immediate safety or

security concerns. The charter should be consistent with event risk insights.

2. At power reactor sites, the charter should not attempt to assess the adequacy of any

longer-term corrective actions used to improve licensee performance and prevent

recurrence of significant conditions since those follow-up activities are addressed

using supplemental or baseline inspections. Performing these activities during a

reactive inspection may delay prompt dissemination of the facts and circumstances

surrounding the significant event and pose unwarranted regulatory burden on

licensees.

3. The charter is generally communicated as an enclosure to a memorandum from the

approving authority to the leader. The charter may be modified during the inspection

in consultation with management when the inspection develops significant new

information that warrants review.

C. Schedule

The reactive inspection must be activated as soon as practicable after the health and

safety significance of the event is determined and should begin its inspection as soon as

practicable after the facility has been placed in a safe, secure, and stable condition.

D. Composition and Qualifications

AIT and SI lead, team composition, and qualifications are defined in IP 93800 and

IP 93812, respectively.

E. Follow Up

1. Identification, review of licensee corrective actions, actions necessary for resumption

of facility operations, and enforcement actions must be accomplished through the

normal organizational structure and procedures.

2. After the inspection is documented, the inspection team should consider providing

feedback to the appropriate headquarters division director with copy to the office

director on any suggested changes to prevent or reduce the frequency of similar

significant events or to enhance oversight. Based on this feedback and the results of

the inspection, management will initiate appropriate follow-up actions. Generally,

staff will handle any follow-up actions through the normal organizational structure

and procedures.