ML26077A033
| ML26077A033 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos Nuclear Center (R-033) |
| Issue date: | 03/17/2026 |
| From: | Ball A NorthStar Vallecitos |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NSV 26-002 | |
| Download: ML26077A033 (0) | |
Text
Adam W. Ball Vallecitos Site Manager 10 CFR 50.54 NSV 26-002 March 17, 2026 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
NTR Biennial Report Vallecitos Nuclear Center Docket No. 50-73 License No. R-33 This submittal satisfies Nuclear Test Reactor (NTR) Technical Specifications (TS) requirement to submit a biennial report to the NRC Document Control Desk in accordance with the provisions of 10 CFR 50.59 per TS 6.9:
TS 6.7.1(1): Tabulation of major preventive and corrective maintenance activities having safety significance.
Response: There have not been any major preventive and corrective maintenance activities having safety significance during the period of January 1, 2024 to December 31, 2025. However, consistent with past facility practices, the following two corrective maintenance, non-safety significant activities were performed during the period and are documented for completeness:
- 1. 4/8/25 - Primary System Differential Pressure Detector Isolation Valve During routine maintenance on the differential pressure detector, it was discovered that one of the isolation valves for the system was not functioning properly. The valve was replaced and all required retests were completed satisfactorily.
- 2. 6/30/25 - Stack Gas and Particulate Chart Recorder During a routine entry into the control room, it was noted that the portion of the chart recorder that contacts the chart paper via solenoid action was no longer contacting the chart paper. Work package FAC-MUCWP-039 was generated and performed to restore functionality. Troubleshooting identified that a ribbon cord in the recorder had broken. A spare was installed and functionality was restored.
TS 6.7.1(2): A report in accordance with 10 CFR 50.59(d)(2) containing a brief description of any changes, tests, and experiments, including a summary of the evaluation of each.
Response: There were no changes, tests or experiments conducted in accordance with 10 CFR 50.59(d)(2). There was a change conducted per 10 CFR 50.90 to implement NRC License R-33 Possession Only Authorization Amendment 26 which completed the required shutdown configuration actions1.
1 Reference GEH letter to USNRC GEH Possession Only License Shutdown Configuration of the GE Nuclear Test Reactor (NTR), dated April 8, 2024 (ML24099A153) (NSV 24-010)
NorthStar Vallecitos, LLC 6705 Vallecitos Rd.
Sunol, Ca 94586 www.northstar.com
NSV 26-002 / Page 2 of 3 TS 6.7.1(3): Summarized results of environmental surveys performed outside the FACILITY.
Response
NTR Stack Total airborne release (stack emissions) for 2024 are as follows:
Alpha Particulate: 1.25E-08 Ci Beta/Gamma Particulate: 3.10E-07 Ci Iodine: <MDA Noble Gas: N/A2 Total airborne release (stack emissions) for 2025 are as follows:
Alpha Particulate: 8.73E-09 Ci Beta/Gamma Particulate: 2.74E-07 Ci Iodine: <MDA3 Gamma Radiation Site perimeter environmental monitoring dosimeters showed radiation dose levels during the report period to be consistent with normal environmental background levels.
Vegetation and Sediment During the report period several vegetation sample radioactivity levels exceeded local action levels but were below regulatory limits. These samples were all further analyzed and radioactivity levels were shown to not be attributable to VNC operations. (See 2025 Effluent Report for details)
During the report period sediment sample radioactivity levels were below local action levels and showed no increased radioactivity levels attributable to VNC operations.
Water During the report period there was no release of radioactivity in basin discharges or to groundwater greater than the limits specified in 10 CFR 20, Appendix B, Table 2, Column 2.
Several water sample radioactivity levels exceeded local action levels but were below regulatory limits. These samples were all further analyzed and radioactivity levels were shown to not be attributable to VNC operations. (See 2025 Effluent Report for details)
Air Sampling During the report period there was no release of radioactivity in the air greater than the limits specified in 10 CFR 20, Appendix B, Table 2, Column 1.
TS 6.7.1(4): A summary of exposures received by FACILITY personnel and visitors where such exposures are greater than 25% of that allowed or recommended.
Response: There have not been any individuals exposed to greater than 25% of that allowed or recommended during the period of January 1, 2024, to December 31, 2025.
NTR is currently staffed to safely possess the reactor and fuel with the reactor safety systems in the possession-only license shutdown configuration, as required the R-33 License and technical specifications.
2 Noble gases are no longer monitored since the NTR is permanently shut down.
3 Iodine sampling was discontinued on 12/8/2025. See RP Memo RPE-2025-003: Discontinuance of Charcoal Filter Sampling and Analysis, dated 8-27-25.
NSV 26-002 / Page 3 of 3 This letter contains no new regulatory commitments.
Should you have any questions concerning this letter, or require additional information, please contact Mr. Thomas B. Silko at (802) 451-5354, Ext 2506.
Sincerely, Adam W. Ball, Vallecitos Site Manager cc: Director, Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555 Regional Administrator, Region 4 U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, Texas 76011-4511 Sincerely, Adam W. Ball,