Campus Alert Archive
Purdue

Three Times the Licensed Power for Nearly a Year: Purdue's PUR-1 Reactor Ran Overpowered Without Anyone Knowing

INotheradvisoryhigh confidence
Confirmed Threat

Between October 31, 2019 and September 15, 2020, the Purdue University Research Reactor (PUR-1) operated at steady-state power levels approximately three times higher than its licensed maximum of 12 kilowatts due to nuclear instrument calibration errors introduced when the instrumentation system was replaced. Purdue reported the event to the NRC on October 20, 2020, and the NRC issued a Notice of Violation on February 16, 2021, for two violations. The excess power stayed well below levels that could damage fuel or safety systems; no students or campus personnel were endangered.

Alerts
2
Response
—
Killed
0
Injured
0
Institution
Purdue University
Public R1 · IN
~50,000 studentsPurdue Alert
Confirmed Timeline

Alert Sequence

2 messages in sequence

Some alert texts below are approximate reconstructions from news coverage, not confirmed verbatim transcripts. Reconstructed texts are shown in italic with a dashed border. Verified verbatim texts have a solid border and are marked accordingly.

INITIAL ALERTUnknown
Approximate reconstructionReconstructed from NRC Event Notification 54958 and the NRC news release No. 20-053 (October 27, 2020) describing the special inspection at the Purdue University Research Reactor627 chars
Purdue University Research Reactor has submitted Event Notification 54958 to the NRC. The notification concerns operation of the PUR-1 reactor at steady-state power levels in excess of the licensed maximum of 12 kilowatts thermal on multiple occasions between October 31, 2019 and September 15, 2020. The overpowering resulted from calibration errors in the nuclear instrumentation system following replacement of the NI system and detectors, causing instruments to indicate power levels approximately three times lower than actual. Corrective actions are being implemented. No fuel damage or safety system actuations occurred.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

Event Notification 54958 was submitted October 20, 2020; the NRC news release confirming the special inspection was issued October 27, 2020
The NI calibration error caused instruments to read approximately one-third of actual power -- meaning operators believed they were running at 4 kW when actual power was approximately 12 kW or more
PUR-1 is a 12-kW pool-type research reactor in the Neil Armstrong Hall of Engineering at Purdue; it is one of the lowest-powered university research reactors in the US, which is why the excess power remained far below levels that could damage fuel
UPDATEWebsite
Approximate reconstructionReconstructed from NRC Notice of Violation document ML21035A348, issued February 16, 2021, to Purdue University regarding PUR-1 License Conditions661 chars
The NRC has issued a Notice of Violation to Purdue University for two violations identified during the special inspection of the PUR-1 Research Reactor. Violation 1: PUR-1 operated at steady-state power levels in excess of the licensed 12 kW limit on multiple occasions between October 31, 2019 and September 15, 2020 (License Condition 2.C.1). Violation 2: Failure to perform appropriate surveillance testing before considering the nuclear instrument system operable following replacement of the NI system and detectors (Technical Specification 4.2.g). The NRC is not proposing a civil penalty, recognizing Purdue's prompt and comprehensive corrective actions.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The NRC's decision not to propose a civil penalty was based on Purdue's prompt, comprehensive corrective actions -- consistent with the NRC's enforcement discretion policy for licensees that self-identify and correct violations
The two violations were License Condition 2.C.1 (thermal power limit) and Technical Specification 4.2.g (surveillance testing after instrument replacement) -- both procedural/technical rather than safety-barrier violations
PUR-1 operates in the basement of the Neil Armstrong Hall of Engineering; the reactor building is shielded and licensed, and excess power at the PUR-1's operational range does not produce measurable radiation outside the reactor bay
Context

Background

The Purdue University Research Reactor (PUR-1), located in the basement of the Neil Armstrong Hall of Engineering in West Lafayette, Indiana, is a 12-kilowatt pool-type reactor licensed for educational research. It is one of the lowest-powered university research reactors in the United States. In the period from late 2019 through mid-2020, the PUR-1 underwent replacement of its nuclear instrumentation (NI) system and detectors -- a significant maintenance operation. The replacement introduced calibration errors: the new instruments indicated reactor power levels at approximately one-third of actual values. As a result, the reactor operated at actual steady-state power levels exceeding the licensed 12 kW limit on multiple occasions between October 31, 2019 and September 15, 2020, without operators or safety systems detecting the discrepancy. Purdue reported the event to the NRC on October 20, 2020 (Event Notification 54958). The NRC conducted a special inspection and, on February 16, 2021, issued a Notice of Violation for two violations: operating above the licensed power limit (License Condition 2.C.1) and failure to perform required surveillance testing after the NI system replacement (Technical Specification 4.2.g). Because Purdue took prompt and comprehensive corrective action, the NRC did not propose a civil penalty. The actual excess power, while well above the licensed limit on a percentage basis, remained far below the levels that could have damaged PUR-1's fuel or safety systems, and no radiation was released outside the shielded reactor bay. No campus-wide alert was issued because the reactor's licensed exclusion zone prevented any public exposure.
Analysis

Key Findings

PUR-1 operated at approximately three times its licensed 12 kW power limit for nearly a year due to an NI calibration error introduced during instrument replacement
The calibration error caused instruments to read roughly one-third of actual power -- a systematic underreading that persisted until investigators discovered the discrepancy in fall 2020
NRC issued two violations but no civil penalty, recognizing Purdue's prompt corrective actions; the excess power never approached levels that could damage fuel or safety barriers
No campus alert was issued; PUR-1's low power level meant the exceedance posed no radiation risk outside the licensed reactor bay
Outcome
NRC issued a Notice of Violation on February 16, 2021, for two violations. No civil penalty was assessed, recognizing Purdue's prompt corrective actions. The reactor's nuclear instrumentation system was recalibrated. No fuel or safety system damage occurred. No campus alert was issued.
Provenance

Sources

  1. Report
    Purdue University Reactor -- Notice of Violation (NRC, February 16, 2021)
    nrc.gov
  2. Report
    NRC News Release No. 20-053 (October 27, 2020) -- Purdue University PUR-1 Special Inspection
    nrc.gov
  3. Source
    Purdue University Reactor Number One -- Wikipedia
    en.wikipedia.org
  4. Official
    Reactor -- Nuclear Engineering -- Purdue University
    engineering.purdue.edu
Tags
nuclear-reactorresearch-reactorPUR-1NRC-violationcalibration-erroroverpoweredradiologicalpublic-r1Indiana
Added June 2026Updated June 2026Via ingestion