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FCSS Interim Staff Guidance-12, Revision 1

10 CFR Part 70, Appendix A - Reportable Safety Events

1 Issue

Prepared by

Division of Fuel Cycle Safety and Safeguards

Office of Nuclear Material Safety and Safeguards

This guidance addresses event reporting criteria in Appendix A to Title 10 of the Code of

Federal Regulations (10 CFR) Part 70 (Appendix A).

2 Introduction

Effective October 18, 2000, licensees subject to the 10 CFR 70.62 integrated safety analysis 

(ISA) summary requirements were required to report events in accordance with Appendix A. 

Event reporting is an important part of the regulatory framework because it provides the U.S. 

Nuclear Regulatory Commission (NRC) with real-time information about unfolding conditions at 

its regulated facilities, allows it to inform other licensees of potentially safety-significant concerns 

at other fuel facilities, and contributes to performance-based regulation through monitoring and 

trending of performance.

A number of issues concerning the interpretation of Appendix A reporting requirements have 

arisen since its implementation. In June 2007, industry representatives and NRC staff met to 

discuss these issues and other areas where conflicting interpretations had resulted in events or 

conditions not being reported in accordance with Appendix A. Industry presented a white paper 

prepared by the Nuclear Energy Institute documenting some of the challenges and 

inconsistencies regarding reportability. The NRC staff, having also observed inconsistent 

reporting of events under Appendix A, had developed a matrix of reporting issues based on 

actual events.

The purpose of this Interim Staff Guidance (ISG) is to clarify some of the reporting requirements 

in Appendix A, which contains criteria for submitting one hour reports, twenty-four hour reports, 

and concurrent reports. These criteria are discussed below.

3 Discussion

3.1 Time of Discovery – Paragraphs (a) and (b) of Appendix A

Paragraphs (a) and (b) of Appendix A pertain to one-hour and twenty-four hour reports, 

respectively, and are tied to when the reportable event is discovered. One-hour reportable 

events are significant operational events that must be quickly reported. Such events typically do 

not require substantial evaluation to determine reportability (e.g., an event involving the loss of

all controls, such that a release or criticality accident is possible). However, if a licensee cannot 

determine whether an event requires reporting under paragraph (a) of Appendix A, the licensee 

should assume that the one hour rule is applicable.

1 Twenty-four-hour reportable events have

1 Additional guidance can be found in NUREG-1520, “Standard Review Plan for the Review of a License 

Application for a Fuel Cycle Facility,” Section 5.4.3.4.7 (7)(d) which states that, “If the licensee cannot 

ascertain within one hour of whether the criteria of 10 CFR 70 Appendix A Paragraph (a) or (b) apply, the 

event should be treated as a one-hour reportable event.”
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less safety significance than one-hour reportable events and sometimes require more extensive 

evaluation to determine reportability. The twenty-four hour time period for reportable events is 

intended to allow licensees sufficient time to make this determination. However, if the 

determination cannot be completed within this time frame then the event must be reported to the 

NRC Operations Center within twenty-four hours of discovery. Licensees are encouraged to be 

conservative in making decisions of reportability, in order to ensure compliance with the

specified time periods established in the regulations. Event reports may be corrected or 

supplemented in accordance with 10 CFR 70.74(a)(4), as appropriate. The flowchart in

Attachment A of this guide illustrates an example of a typical notification process at a fuel cycle

facility.

The time of discovery begins when a cognizant individual observes, identifies, or is notified of a 

safety significant event or condition. A cognizant individual is anyone who, by position or 

experience, is expected to understand that the particular condition or event adversely impacts 

safety. For some conditions, such as the examples2 shown in Table 1 and Attachment B, an 

investigation and evaluation is necessary and may lead to the discovery of a potentially 

reportable situation. This evaluation should proceed on a time scale commensurate with the 

safety significance of the issue.

Table 1 Examples of discovery determination

Issue Discovery Determination

Poor quality uranium powder is observed and 

reported as being discharged from a heated 

calciner process.

After the process was shutdown and the equipment 

was disassembled, it was discovered that the 

calciner tube had cracked allowing uranium to 

accumulate outside of the analyzed geometry.

A crack is found in a solution process area that may

have allowed uranium-bearing solutions to 

accumulate beneath the floor. Initial probing could 

not determine the extent or depth of the crack. The 

licensee had not anticipated any problems but was 

aware of prior spills of uranium solution in the area 

and decided to investigate further. Arrangements 

were made to remove the damaged section of floor 

in this area and soil samples were collected.

Upon analysis of the soil samples, it was 

discovered that a mass of uranium had 

accumulated in an unanalyzed area beneath the 

floor.

A small release of UF6 occurred during a cylinder 

change-out inside a process area. Although the air 

monitoring system in the area did not alarm, an 

operator reported he was working in the area

during the release.

The time of discovery is when the operator 

realized he may have been exposed. Nasal 

smears did not indicate a significant intake

occurred. At this point the licensee had reasonable 

justification for not reporting the event since it did 

not appear to meet the reporting requirements.

One hour, eight hour and twenty-four hour urine 

samples were collected and analyzed, which 

revealed the worker had received an intake of 

approximately 40mg of uranium. This constituted a 

new time of discovery.

2 These examples are not meant to be an exhaustive list and should not be used as such.
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3.2 Loss or Degradation of Items Relied on for Safety (IROFS) –

Paragraphs (a)(4) and (b)(2) of Appendix A

10 CFR 70.61(e) requires that the controls needed to meet the performance requirements (i.e.,

§§ 70.61(b), 70.61(c), and 70.61(d)) must be designated as IROFS. In addition, each IROFS

must be described in the ISA (§70.62(c)(1)(vi)) and in the ISA Summary (§70.65(b)(6)). Thus, 

for the reporting requirements of Appendix A, no control can be credited which is not listed as 

an IROFS in the ISA Summary.

When a licensee discovers a condition where there are one or more failed or degraded IROFS, 

it must assess whether such an event or condition is reportable under Paragraphs (a)(4) or

(b)(2) of Appendix A. All situations where IROFS have failed or degraded are reportable under

Paragraphs (a)(4) or (b)(2), except for the following:

1. The failed or degraded IROFS are not needed to meet the performance requirements.

Thus, the ISA Summary should indicate that the remaining IROFS are sufficient to meet 

the performance requirements.

2. IROFS listed for other accident sequences are applicable to the accident sequences 

where the ISA Summary indicates that the failed or degraded IROFS were needed to 

meet the performance requirements. These other IROFS must be in place physically 

where the event occurred, and must be available and reliable when the event occurred; 

the IROFS must also perform a safety function that prevents or mitigates the event in 

question. In this case, the performance requirements were met, but had not been 

adequately demonstrated in the ISA Summary.

3. The capabilities of the degraded IROFS are still sufficient to meet the performance 

requirements.

Licensees may also apply IROFS from another sequence, in the manner described above, to 

report under Paragraph (b)(2) instead of Paragraph (a)(4).

3.3 Inadequate ISA – Paragraph (b)(1) of Appendix A

When a licensee discovers an unanalyzed condition and determines that the ISA is not 

adequate to demonstrate that the performance requirements are met, it must assess whether 

this event or condition is reportable under Paragraph (b)(1).

As mentioned in the previous section, controls which are needed to meet the performance 

requirements must be designated as IROFS. However, it is recognized that failing to properly 

document controls does not always pose a safety concern that is significant enough to warrant 

reporting to the NRC. The following guidance distinguishes between situations where an event 

occurred and situations where no event occurred in relation to the situation where the ISA is 

discovered to be inadequate. The reason for this distinction is that the occurrence of an event 

represents an actual challenge to the safety basis.
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Event occurs

The licensee should presume that the event could lead to a high consequence until it can 

determine otherwise.

• In the case where IROFS were identified, but the event was improperly analyzed, the 

condition should first be evaluated under the section above (Loss or Degradation of 

IROFS). If none of the criteria in that section are met, then the event should be 

reported under Appendix A, Paragraph (b)(1) unless it is determined that the 

performance requirements are met.

• In the case where IROFS were not identified, such as an unanalyzed event or 

condition, the condition should be evaluated under the section above (Loss or 

Degradation of IROFS) with the assumption that no IROFS are available or reliable.

If none of the criteria in that section are met, then the event should be reported under

Appendix A, Paragraph (b)(1) unless it is determined that the performance 

requirements are met.

No event occurs

These situations can include conditions identified during audits, maintenance, testing, 

surveillance, or other management measure activities. However, if events or conditions are 

caused by the conduct of such activities, then they should be treated like other events.

• If available IROFS are sufficient to meet the performance requirements, the condition 

is not reportable under Appendix A, Paragraph (b)(1).

• If available IROFS are not sufficient to meet the performance requirements, the 

condition is reportable under Appendix A, Paragraph (b)(1).

Other situations where it cannot be determined if the performance requirements are met should 

be reported under Appendix A, Paragraph (b)(1).

3.4 External Events - Paragraph (b)(4) of Appendix A

A natural phenomenon (e.g., hurricane, tornado, earthquake, flood, fire) or other external 

condition that poses an actual threat to the safety of the facility must be reported within 24 

hours.

3 Natural phenomenon which damages some portion of the facility would typically be 

reported. Where a phenomenon has not resulted in damage to the facility, the licensee should 

decide if a phenomenon or condition actually threatens the facility. For example, a minor brush 

fire in a remote area of the site that is quickly controlled by fire fighting personnel and, as a 

result, did not present a threat to the facility should not be reported. However, a major forest 

fire, large-scale flood, or major earthquake that presents a clear threat to the facility should be 

reported. As another example, an industrial or transportation accident which occurs near the 

site, creating a safety concern, should be reported.

The licensee must use judgment to determine if an external event threatens the facility. For 

example, with regard to tornadoes the decision would be based on such factors as the size of 

the tornado, and its location. There are no prescribed limits. In general, situations involving 

only monitoring by the plant’s staff are not reportable, but if preventive actions are taken or if 

there are serious concerns, then the situation should be carefully reviewed for reportability.

3 For those licensee’s required to have an NRC approved Emergency Plan, it should be noted that the 

reportability of the natural phenomenon events may be superseded by site specific emergency action 

levels (e.g., sustained winds in excess of 70 mph onsite) which, if met, would result in an Emergency Plan 

classification and subsequent one-hour reportability requirement.
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3.5 Concurrent Reports – Paragraph (c) of Appendix A

The purpose of the criterion in Paragraph (c) is to ensure the NRC is made aware of issues that 

will cause heightened public or government concern related either to the health and safety of

the public, on-site personnel or protection of the environment. Licensees typically issue press 

releases or notify local, county, State or Federal agencies on a wide range of topics that are of

interest to the general public. The following clarifications are intended to set a reporting

threshold that ensures necessary reporting, while minimizing unnecessary reporting.

3.5.1 Press Release

The NRC has an obligation to inform the public about issues within the NRC's purview that 

affect or raise a concern about the public health and safety. Thus, the NRC needs accurate, 

detailed information in a timely manner regarding such situations. The NRC Operations Center 

should be made aware of any such information that the licensee has available for the press or 

other government agencies. However, the NRC need not be notified of every press release a 

licensee issues. The field of NRC interest is narrowed by the phrase "related to the health and 

safety of the public or onsite personnel, or protection of the environment," in order to exclude 

administrative matters or those events of no safety significance. Routine radiation releases are 

not specifically reportable under this criterion. However, if a release receives significant media 

attention, the release is reportable under this criterion. If possible, licensees are encouraged to 

notify the NRC Operations Center before issuing a press release because news media 

representatives will usually contact the NRC public affairs officer shortly after its issuance for 

verification, explanation, or interpretation of the facts.

Examples of events that are likely to be reportable to the NRC because they may result in a 

licensee-issued news release include:

• release of radioactively contaminated tools or equipment to public areas

• unusual or abnormal releases of radioactive effluents

• on-site fatality

3.5.2 Other Government Notifications

For reporting purposes, the phrase "other government agencies" in Paragraph (c) of Appendix A 

refers to local, State or other Federal agencies. Notifying another agency does not relieve the 

licensee of the requirement to report to the NRC.

Licensees generally do not have to report media and government notifications to the NRC 

unless they are related to the health and safety of the public or on-site personnel, or protection 

of the environment. For example, the NRC does not generally need to be informed under this 

criterion of the following, even if these events may require notification to another regulatory 

agency:

• minor deviations from sewage or chlorine effluent limits

• minor non-radioactive, onsite chemical spills that do not affect the safety of NRC-license 

material

• minor oil spills

• problems with plant stack or water tower aviation lighting
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• peaceful demonstrations

• routine reports of effluent releases to other agencies

The examples in Attachment C of this guide provide additional guidance on the reportability of 

events under Paragraph (c) of Appendix A.

4 Regulatory Basis

Appendix A to 10 CFR Part 70

5 Applicability

This ISG is applicable to 10 CFR Part 70 fuel cycle facilities.

6 Recommendation

This guidance should be formalized into a NRC Regulatory Guide.

7 References

U.S. Code of Federal Regulations, Title 10, Energy, Part 70, “Domestic Licensing of Special

Nuclear Material.”

U.S. Nuclear Regulatory Commission. NUREG-1520, “Standard Review Plan for

the Review of a License Application for a Fuel Cycle Facility.” NRC: Washington, D.C., 

March 2002.

U.S. Nuclear Regulatory Commission. NUREG-1718, “Standard Review Plan for

the Review of an Application for a Mixed Oxide (MOX) Fuel Fabrication Facility.” NRC: 

Washington, D.C., August 2000.

NUREG-1022, “Event Reporting Guidelines 10 CFR 50.72 and 50.73,” U.S. Nuclear Regulatory

Commission, Revision 2, October 2000.
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Attachment A

Example of a typical notification process at a fuel cycle facility

Safety Concern, Process Upset, IROFS/Management Measure Failure or Degradation1

Observed by any safety, operations, or maintenance personnel

2

Then Notify:

Shift Team Leader or Supervisor

3

Then Notify:

Safety Discipline Engineer and Management for reportability determination4

1 Example Situations:

• Intended safety function, availability, or reliability of an IROFS has been affected

• Condition that was not analyzed, improperly analyzed, or different from analysis documented in ISA

• Acute chemical exposure requiring medical attention

• Abnormal situation where uranium has accumulated or been released

• Spill or contamination event

• Suspected intake of uranium

• Any situation resulting in a fire.

2 The time between this and the next step (notify supervisor) should proceed in a matter of minutes.

3 Supervision takes lead to coordinate response and recovery.

4 The evaluation should proceed on a time scale commensurate with the safety significance of the issue.
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Attachment B

Additional examples of discovery determination

Issue Discovery Determination

Based on information available, a facility ISA 

determines that a fire impinging on a propane tank 

will result in a torch fire but will not explode because 

the safety valves will adequately relieve pressure. 

Subsequently a worker questions the validity of this 

conclusion. The facility safety and licensing staff 

researches this topic and determines that the safety 

analysis was deficient based upon evidence that 

aluminum propane tanks, which are in use at the 

facility, are more likely to explode in fire scenarios 

than steel tanks.

Discovery occurred when it was determined that the 

safety analysis was deficient and resulted in a failure 

to meet the performance requirements.

A plant engineer notifies the safety staff of a newly 

installed pump that is connected to a fissile solution 

tank that uses an open process air line and a DP 

gauge for a tank level indicator. The safety and 

licensing staff initially determined that this condition is

bounded by a previously analyzed “reverse flow” 

accident sequence. However, upon subsequent 

review of detailed information relating to the pump 

characteristics, the flow path, the quantity of solution 

available, the potential U concentrations in the tank, 

and the location of IROFS that were used to prevent 

reverse flow in the analyzed reverse flow accident 

sequence, the plant safety and licensing staff

determined that the plant condition was not bounded 

by the previously analyzed “reverse flow” sequence.

Discovery occurred when the plant staff determined 

that this reverse flow sequence was improperly 

analyzed in the ISA and resulted in a failure to meet 

the performance requirements.

A nitrous oxide gas detector designated as an 

IROFS to prevent chemical exposures to NOx 

emissions was calibrated in January using a NOx 

standard.

Several months later, it was discovered that the gas 

standard used had a calibration expiration date the 

previous September. No actual emissions occurred; 

however, the licensee had to assume that the

IROFS was in a degraded condition since the last 

functional test. Without this IROFS, the performance 

requirements could not be met. The condition was 

reported to the NRC under Paragraph (b)(2) of 

Appendix A. It was later determined that the nitrous 

oxide gas detector would have been able to perform 

its safety function, and the licensee retracted its 

previous report.
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Attachment C

Examples of Concurrent Reports under Paragraph (c) of Appendix A

On-site Fatality - Government Notifications and Press Release

• A worker fell from an on-site cooling tower inside the controlled area due to an apparent 

heart attack and could not be revived. The licensee notified the local emergency agencies, 

company officials, and the Occupational Safety & Health Administration. The licensee also 

notified the NRC resident inspector and plans to issue a press release. An NRC notification 

was needed because of the fatality on-site, the other government notifications, and potential 

media involvement.

Licensee Media Inquiries Regarding NRC Findings

• As a result of a local newspaper article regarding the findings of an NRC regional inspection 

of the facility fire protection program, a licensee representative was interviewed on local 

television and radio stations. The licensee notified State and local officials. NRC notification 

was not needed because the subject of the radio and TV interviews was an NRC inspection.

State Notification of Improper Dumping of Radioactive Waste

• The licensee transported two exhaust High-Efficiency Particulate Air filters to the city dump 

as nonradioactive waste but later determined they contained radioactive material. The 

dumpsite was closed and the filters retrieved. The licensee notified the appropriate local and 

State agencies. An NRC notification is needed because of the notification to local and State 

agencies of the inadvertent release of radioactively contaminated material off site, which 

affects the health and safety of the public and environment.

Routine Agency Notifications

• A licensee notified the U.S. Environmental Protection Agency (EPA) that a liquid effluent 

exceeded the release permit limit for biological oxygen demand. This event was caused by 

an unexpected loss of a circulating water pump at the site sanitary waste treatment facility. 

NRC notification was not needed because these events are routine and don’t directly involve 

NRC-licensed material.

• A licensee notified the State, EPA, U.S. Coast Guard and Department of Transportation that

15 gallons of diesel fuel oil had spilled onto gravel-covered ground inside the controlled area. 

The spill has minor environmental impact and was cleaned up by removing the gravel and

dirt. NRC notification was not needed because these events are routine and don’t directly

involve NRC-licensed material.
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Glossary

The following definitions apply to the guidance in this document and are not intended to replace 

any or affect Part 70 definitions or regulatory requirements.

Failed (or lost) IROFS: An IROFS that is not available or cannot perform its intended safety 

function; an IROFS that did not perform its safety function.

Degraded IROFS: An IROFS that has not failed, but is in a state of reduced capability or 

reliability.