IR 05000607/2026201
| ML26061A117 | |
| Person / Time | |
|---|---|
| Site: | University of California-Davis (R-130) |
| Issue date: | 03/04/2026 |
| From: | Tony Brown NRC/NRR/DANU/UNPO |
| To: | Frey W McClellan Nuclear Research Center |
| Shared Package | |
| IR 2026201 | List: |
| References | |
| IR 2026201 | |
| Download: ML26061A117 (0) | |
Text
SUBJECT:
REGENTS OF THE UNIVERSITY OF CALIFORNIA - U.S. NUCLEAR REGULATORY COMMISSION SAFETY INSPECTION REPORT NO. 05000607/2026201
Dear Dr. Frey:
From February 23-26, 2026, the U.S. Nuclear Regulatory Commission (NRC) staff conducted an inspection at your University of California-Davis/McClellan Nuclear Research Center. The inspection results were discussed with you and other members of your staff on February 26, 2026. The enclosed report documents the inspection results.
The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.
The inspector reviewed selected procedures and records, observed various activities, and interviewed personnel. Based on the results of this inspection, no violations of more than minor significance were identified. No response to this letter is required.
In accordance with Title 10 of the Code of Federal Regulations Section 2.390, Public inspections, exemptions, requests for withholding, a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of NRCs document system (Agencywide Documents Access and Management System (ADAMS)). ADAMS is accessible from the NRC website at https://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
March 4, 2026 Should you have any questions concerning this inspection, please contact Jonathan Braisted at (301) 287-3482, or via email at Jonathan.Braisted@nrc.gov.
Sincerely, Tony Brown, Chief Non-Power Production and Utilization Facility Oversight Branch Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation Docket No. 50-607 License No. R-130 Enclosure:
As stated cc w/enclosure: GovDelivery Subscribers Signed by Brown, Tony on 03/04/26
ML26061A117 NRC-002 OFFICE NRR/DANU/UNPO NRR/DANU/UNPO/LA NRR/DANU/UNPO/BC NAME JBraisted NParker TBrown DATE 3/2/2026 3/2/2026 3/4/2026
Enclosure U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION Docket No.:
05-607 License No.:
R-130 Report No.:
05000607/2026201 Licensee:
Regents of the University of California Facility:
University of California-Davis, McClellan Nuclear Research Center Location:
McClellan Park, Sacramento, California Dates:
February 23-26, 2026 Inspector:
Jonathan Braisted Approved by:
Tony Brown, Chief Non-Power Production and Utilization Facility Oversight Branch Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation
SUMMARY The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an inspection at the University of California-Davis (UCD)/McClellan Nuclear Research Center (MNRC), in accordance with the research and test reactor inspection program. This is the NRCs program for overseeing the safe operation of licensed research and test reactors. Refer to https://www.nrc.gov/reactors/non-power.html for more information.
List of Violations No violations of more than minor significance were identified.
Additional Tracking Items None.
REPORT DETAILS Facility Status The UCD/MNRC 1 megawatt Training, Research, Isotope, General Atomics (TRIGA) research reactor operates in support of neutron radiography, neutron tomography, experimental sample irradiation, and for tours of students and other members of the public. During the inspection, the reactor was operated several hours per day at various power levels up to 600 kilowatts to support neutron radiography, sample irradiation, and training.
Inspection Scopes Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at https://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html.
Inspections were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter 2545, Research and Test Reactor Inspection Program. The inspector reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
69001 - Class II Research and Test Reactors This inspection included a review of selected aspects of the research and test reactor, since the last inspection, to verify activities were conducted safely and in accordance with regulatory requirements and licensee commitments.
Organization and Staffing (IP Section 02.01)
This inspection included a review of the licensees organizational changes and shift staffing records to verify compliance with technical specification (TS) requirements and licensee commitments. Specifically, the inspection included a review of the following:
annual operating reports
letter for permanent change to the facility organization involving Level 1 personnel
list of management personnel, radiation personnel, and reactor staff along with their contact information
UCD/MNRC TS Operations Logs and Records (IP Section 02.02)
This inspection included a review of the licensees operation logs and records to verify they were maintained and that significant issues were reported and resolved as required by the TSs and the licensees administrative procedures. Specifically, the inspection included a review of the following:
annual operating reports
selected UCD/MNRC operating instructions and procedures
selected UCD/MNRC operations and rounds logs
- selected UCD/MNRC startup and shutdown checklists
UCD/MNRC TS Requalification Training (IP Section 02.04)
This inspection included a review of selected documents pertaining to operator requalification training to verify requirements of the licensees approved requalification plan and Title 10 of the Code of Federal Regulations Part 55, Operators Licenses were met. Specifically, the inspection included a review of the following:
letter requesting termination of operator license
selected operator medical examinations
selected requalification and relicensing status sheets
selected training materials
selected UCD/MNRC comprehensive written examination results
selected UCD/MNRC operations logs
selected UCD/MNRC reactor facility annual operating test results
selected UCD/MNRC training form sign-in sheets
status of qualified operators licenses
UCD/MNRC 2024-2026 training schedule
UCD/MNRC reactor selection and training plan Surveillance and Limiting Conditions for Operation (IP Section 02.05)
This inspection included a review of surveillances listed in the TSs to verify requirements were met. Limiting conditions for operation were also reviewed to verify that operating conditions were maintained in accordance with the licensees procedural requirements. Specifically, the inspection included a review of the following:
selected UCD/MNRC operations logs
selected UCD/MNRC startup and shutdown checklists
selected UCD/MNRC work order forms
UCD/MNRC preventive maintenance system twelve month schedule
UCD/MNRC reactor operations status sheet
UCD/MNRC TS Maintenance Logs and Records (IP Section 02.11)
This inspection included a review of the licensees maintenance logs and records to verify that operational and maintenance activities were conducted and maintained in accordance with regulatory and TS requirements. Specifically, the inspection included a review of the following:
selected UCD/MNRC anomaly worksheets
selected UCD/MNRC operation and maintenance manuals
selected UCD/MNRC operations logs
selected UCD/MNRC work order forms
UCD/MNRC preventive maintenance system twelve month schedule
UCD/MNRC TS
Fuel Handling Logs and Records (IP Section 02.12)
This inspection included a review of the licensees fuel handling logs and records to verify TS and procedural requirements were met. Specifically, the inspection included a review of the following:
selected fuel handling checklists
selected fuel measurement log and data
selected fuel transfer forms
selected UCD/MNRC operation and maintenance manuals
selected UCD/MNRC operations logs
selected UCD/MNRC work order forms
UCD/MNRC core configuration Inspection Results No violations of more than minor significance were identified.
Minor Violation (VIO 05000607/2026201-01)
69001.02.05 Minor Violation: On February 1, 2023, the licensee notified the NRC Operations Center upon discovery of operation in violation of a limiting condition for operation in accordance with TS 6.7.2.1.d. The NRC logged this as Event Number56331. The licensee followed up the initial notification with a written report dated February 14, 2023 (Agencywide Documents Access and Management System Accession No. ML23045A320).
On January 31, 2023, the licensee reviewed pool water tritium concentration results that a private laboratory analyzed. TS 4.3.4 requires semiannual measurements of pool water radioactivity, including tritium. The licensee discovered that the analyzed values were incorrect and underreported by a factor of 100. Consequently, the actual tritium concentration was determined to exceed the TS limit by approximately 2.5 times. The licensee then suspended reactor operations.
TS 3.3.4 states, in part, that [t]he reactor shall not be operated if the radioactivity of the pool water exceeds the limits of 10 CFR 20 Appendix B Table 3 for radioisotopes with half-lives >24 hours.
Contrary to the above, between November 21, 2022, and January 30, 2023, the reactor was operated when the radioactivity of the pool water exceeded the limits of 10 CFR 20 Appendix B Table 3 for radioisotopes with half-lives >24 hours. Specifically, the pool water tritium concentration exceeded the monthly average concentration limit for tritium specified in 10 CFR Part 20 Appendix B Table 3.
Screening: The inspector determined that the violation was of minor significance because it resulted in no safety or security impacts and did not correspond to any examples of more-than-minor violations described in the NRC Enforcement Policy. The measured tritium concentrations were consistent with historical trends, and the licensee had not discharged any pool water since new radioactivity limits were incorporated into the TS on November 21, 2022.
Enforcement: The licensee took corrective actions to restore compliance, including suspending operations and submitting a license amendment request to increase the allowable pool water tritium concentration. The NRC subsequently approved this revised limit on March 2, 2023 (ML23045A045), allowing the licensee to resume operations. This failure to meet TS 3.3.4 is considered a minor violation and, in accordance with the NRC Enforcement Policy, does not warrant enforcement action.
This closes EN 56331.
Exit Meeting and Debriefs The inspector verified no proprietary information was retained or documented in this report.
- On February 26, 2026, the inspector presented the inspection results to D and other members of the licensee staff.
Documents Reviewed Inspection Procedure Type Designation Description or Title Revision or Date MNRC-0004-DOC-16 Technical Specifications for the University of California - Davis McClellan Nuclear Research Center (UCD/MNRC)
February 7, 2025 69001.02.01 Miscellaneous University of California, Davis McClellan Nuclear Research Center (MNRC) License Holder Appointment November 27, 2023 2024 Annual Report May 5, 2025 2023 Annual Report May 22, 2024 UCD/MNRC-0016-DOC-13 Figure 3.2 UCD/MNRC Startup Checklist January 7, 2024-February 23, 2026 UCD/MNRC-0016-DOC-13 Figure 2.2 UCD/MNRC Facility Rounds Log January 5, 2023-February 20, 2026 UCD/MNRC-0016-DOC-13 Figure 5.1 UCD/MNRC Shutdown Checklist January 11, 2024-February 20, 2026 Miscellaneous UCD/MNRC Operations Log 199, 202-205 69001.02.02 Procedures UCD/MNRC-0016-DOC-
UCD/MNRC Operating Instructions December 19, 2024 MNRC-0009-DOC-05 University of California - Davis/
McClellan Nuclear Research Center Reactor Selection and Training Plan for Reactor Personnel September 22, 2021 69001.02.04 Miscellaneous Requesting Termination of SRO License July 1, 2025
Inspection Procedure Type Designation Description or Title Revision or Date UCD/MNRC Reactor Facility Annual Operating Test for Senior Reactor Operators 2024 UCD/MNRC Reactor Facility Annual Operating Test for Reactor Operatores and Senior Reactor Operators 2025 MNRC-0012-OMM-05 MNRC Reactor OMM 5110 Primary Cooling System Operation and Maintenance Manual November 12, 1999 UCD/MNRC-0011-OMM-
OMM 5240 Fuel - UCD MNRC Operation and Maintenance Manual August 13, 2024 MNRC-0013-OMM-04 UCD/MNRC Reactor Control Rod System Operation and Maintenance Manual 5140 September 18, 2000 UCD/MNRC-0016-DOC-
UCD/MNRC Operating Instructions December 19, 2024 Miscellaneous MNRC-0038-OMM-01 MNRC OMM 5330 Nuclear Instrumentation Operation and Maintenance Manual November 18, 2008 MNRC Work Order Fuel Temperature Calibration 25-0393 MNRC Work Order NM-1000 Calibration 25-0400 MNRC Work Order Reactor Power Calibration 25-0402 MNRC Work Order Measure Control Rod Reactivity Worths 24-0435 MNRC Work Order Low Source RWP Interlock Test 26-0090, 24-0078 69001.02.05 Work Orders MNRC Work Order Simultaneous Control Rod Withdrawal Interlock Test 26-0091, 24-0079
Inspection Procedure Type Designation Description or Title Revision or Date MNRC Work Order Reactor Tank Water Low-Level Alarm Test 26-0082, 24-0425, 24-0071 MNRC Work Order Measure Control Rod Drop Times 24-0441, 24-0080 MNRC Work Order Measure Core Excess Reactivity 24-0438 MNRC Work Order Verify Shutdown Margin 24-0437 MNRC-0014-0MM-04 Reactor Room Ventilation System Operation and Maintenance Manual
- 5620 September 22, 1997 MNRC-0039-OMM-03 UCD/MNRC Reactor Personnel Shield and Radiography Shutter Operation and Maintenance Manual #5420 January 11, 2008 MNRC-0013-OMM-04 UCD/MNRC Reactor Control Rod System Operation and Maintenance Manual 5140 September 18, 2000 MNRC-0015-OMM-06 MNRC Reactor OMM 5120 Demineralizer System Operation and Maintenance Manual January 5, 2009 ANOM-26-02 AC-1 Damper Actuator Malfunction February 5, 2026 ANOM-25-04 FOD in Reactor Tank March 26, 2025 ANOM-25-03 Shim 1 Drive Noise June 24, 2025 Miscellaneous MNRC-0071-DOC-00 Core Reflooding System MNRC Work Order Test Recirculation System 25-0696, 26-0104 MNRC Work Order Inspect G-Ring Positions for Changes in Element Orientation 25-0787, 25-0782 MNRC Work Order Neutron Shutters and Shields 25-0785 69001.02.11 Work Orders MNRC Work Order Clean, Inspect & Lubricate Rod Drives 24-0440
Inspection Procedure Type Designation Description or Title Revision or Date MNRC Work Order Inspect Control Rods 24-0434 MNRC Work Order Clean, Inspect & Lubricate TR 24-0439 MNRC Work Order Reactor Room Ventilation System 25-0779, 26-0139 MNRC Work Order Primary Chemistry 25-0756, 25-0682 MNRC Work Order Control Rod and Drive 25-0129, 25-0312 MNRC Work Order Test RAMs and CAMs 25-0754, 25-0672 MNRC Work Order CRS Valve Cycling and Flow Verification Check 26-0092, 25-0484, 24-0081 UCD/MNRC-0019-OMM-
MNRC Reactor OMM 5220 Fuel Handling Tools Operation and Maintenance Manual January 12, 2009 UCD/MNRC-0011-OMM-
OMM 5240 Fuel - UCD MNRC Operation and Maintenance Manual August 13, 2024 MNRC-0013-OMM-04 UCD/MNRC Reactor Control Rod System Operation and Maintenance Manual 5140 September 18, 2000 Fuel Handling Checklist July 28-29, 2025 Fuel Handling Checklist July 29, 2024 UCD/MNRC Operations Log 199, 204 MNRC Core Configuration July 22, 2025 MNRC Core Configuration July 25, 2024 Fuel Transfer Form July 25, 20245 69001.02.12 Miscellaneous Fuel Transfer Form July 22, 2025
Inspection Procedure Type Designation Description or Title Revision or Date 2025 Control Rod and Fuel Inventory Summary July 31, 2025 MNRC Work Order Fuel Inspection 25-0392 MNRC Work Order Calculate the Worth of the Most Reactive Fuel Element and Graphite Element 25-0394, 24-0386 Work Orders MNRC Work Order Inspect Fuel Storage Racks 24-0385