ML25175A350

Idaho State University, Annual Operating Report for 2024 Calendar Year

ML25175A350
Person / Time
Site:	Idaho State University
Issue date:	04/28/2025
From:	Idaho State University
To:	Office of Nuclear Reactor Regulation
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ML25175A348	List: ML25175A350
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Idaho State University AGN-201m Reactor 2024 Annual Report Page 1 of 8 Idaho State University AGN-201M Reactor Facility License R-110, Docket No. 50-284 Annual Operating Report for 2024 Calendar Year

1. Narrative Summary A. Changes in Facility Design, Performance Characteristics, and Operating Procedures Two major changes to the Facility Design, Performance Characteristics, and Operating Procedures were made in 2024.

1)

Issuance of Amendment NO. 8 to Renewed Facility License NO. R-110 a)

The license was amended to remove the Channel 2 low power scram in preparation for replacing existing Channels 2 and 3 BF3 neutron detectors with new B-10 lined detectors that have less sensitivity at very low power.

2)

Implementation of ISU-50.59-2024-1 Soft Shutdown.

a)

The reactor now can be shut down by removing the control rods in the reverse order of insertion. This method of shutdown is preferred over manual scram in order to lessen the wear on the control rod drives.

B. Results of major Surveillance Tests and Measurements

1) The period, count rate, and power level measuring channels were calibrated and set points were verified. Channels 1, 2, & 3 were tested on 06/03/2024.

2) Power level (06/03/2024) and period check (06/03/2024) experiments were performed with satisfactory results.

3) The shield water tank was inspected (05/20/2024) and no excessive corrosion was observed. The known existing shield water tank leak continues to be monitored. The Water Level interlock tested satisfactorily (05/20/2024).

4) The Seismic Displacement & Temperature interlocks were tested and found satisfactory on 05/20/2024.

5) Control element capsules (cladding) were inspected (05/20/2024) and found to be in good condition with no evidence of deterioration since the previous inspection

6) The control rod drive mechanisms were inspected (05/20/2024) and tested with satisfactory results.

7) Ejection times were measured for all SCRAM-able rods (SR-1, SR-2, and CCR) and were found to be 0.15, 0.10, and 0.10 seconds, respectively. The requirement that ejection times be less than 1 second is satisfied.

Idaho State University AGN-201m Reactor 2024 Annual Report Page 2 of 8

8) The reactivity worth of the Fine Control Rod, Safety Rods 1 and 2, and the Course Control Rod were measured. The time to drive each rod fully into the core was measured as part of performing Maintenance Procedure 1. The largest reactivity insertion rate is 0.0321

, which is less than the tech spec limit of 0.065

9) The shutdown margin (SDM) with the most reactive SCRAM-able rod and the Fine Control Rod fully inserted was determined to be 2.28 (at maximum allowable k excess 0.65

. This value meets the tech spec requirement that the SDM be greater than 1 C. NRC Inspections The annual inspection was conducted by Craig Bassett on August 12 - August 15, 2024.

No violations or findings of significance were identified.

2.

Operating History and Energy Output The reactor was operated at power levels up to 4.5 Watts for a total of 146.0397 Watt-hours of thermal energy during this reporting period. A summary of monthly operations for 2024 is given in Table I.

Table I. Summary of Monthly Reactor Operations (1 January 2022 through 31 December 2022)

Year Totals January 13.0310 Watt-hr February 17.3695 Watt-hr March 24.2663 Watt-hr April 14.8408 Watt-hr May 36.1880 Watt-hr June 0.000 Watt-hr July 2.7333 Watt-hr August 6.2083 Watt-hr September 15.7520 Watt-hr October 0.0227 Watt-hr November 1.3210 Watt-hr December 14.3067 Watt-hr Total 146.0397 Watt-hr 0.1460 kWatt-hr The 0.1460 kWatt-hr consumed 6.40 µgrams of U-235 using Equation (1) 235 = () (

3600 1 ) (

6.2421012 1

) (

1 200 ) (

1.17 235 1

) (

1 235 6.0221023 235) (

235 235 1 235) (1)

Idaho State University AGN-201m Reactor 2024 Annual Report Page 3 of 8 During the calendar year, several students went through reactor operator training. During the calendar year, 10 students and 2 staff took NRC licensing exams, 10 Reactor Operator (RO) and 1 Senior Reactor Operator (SRO) licenses were awarded.

3. Unscheduled Events and Inadvertent SCRAMS A. Inadvertent SCRAMS and Actions Taken There were 21 inadvertent scrams during this reporting period. Table II summarizes the inadvertent scrams, known or suspected cause, actions taken and resolution.

Table II. Summary of Inadvertent Scrams (1 January 2024 through 31 December 2024)

Inadvertent scrams Date Time Scram Type Cause Resolution Action 2/5/2024 14:55 Channel 2 Low Electrical Noise Amendment No. 8 & new detectors acquired Restart 2/9/2024 15:00 Channel 3 Low Range Switch while ranging down Investigate purchase of new switch if this occurs frequently Restart 3/14/2024 14:51 Channel 3 Low Operator bumped console Instruct operator to be aware of console Shutdown 4/2/2024 11:37 Channel 2 Low Electrical Noise Amendment No. 8 & new detectors acquired Shutdown 4/2/2024 14:30 Channel 2 Low Electrical Noise Amendment No. 8 & new detectors acquired Restart 4/11/2024 14:31 Channel 3 Low Operator error (wrong direction on switch)

Instruct operator on direction of range switch Shutdown

Idaho State University AGN-201m Reactor 2024 Annual Report Page 4 of 8 4/25/2024 14:47 Channel 2 Low Operator bumped a wire Instruct operator to be aware of console Restart 5/13/2024 14:18 Channel 2 Low Electrical Noise Amendment No. 8 & new detectors acquired Restart 5/15/2024 9:48 Channel 3 High Operator Error (2 ranges at once)

Instruct operator on force needed to change range on switch Restart 5/22/2024 12:24 Channel 3 Low &

High Operator bumped console Instruct operator to be aware of console Restart 5/22/2024 13:48 Channel 3 High Operator Error (2 ranges at once)

Instruct operator on force needed to change range on switch Restart 7/2/2024 10:42 Power Outage Construction Wait till construction completed Restart 7/2/2024 10:50 Channel 2 High Channel 2 setpoint drift Re-adjusted Channel 2 High setpoint Shutdown 9/3/2024 14:26 Channel 2 Low Electrical Noise Amendment No. 8 & new detectors acquired Shutdown 9/10/2024 12:57 Channel 2 Low Electrical Noise from construction vibration Amendment No. 8 & new detectors acquired Shutdown 9/19/2024 16:22 Channel 3 Low Operator Error Instruct operator when to switch ranges Shutdown

Idaho State University AGN-201m Reactor 2024 Annual Report Page 5 of 8 11/7/2024 10:18 Reactor Period Electrical Noise from static New detectors acquired Shutdown 12/5/2024 10:33 Channel 3 Low Range Switch while ranging down Investigate purchase of new switch if this occurs frequently Restart 12/5/2024 11:40 Channel 3 Low Range Switch while ranging down Investigate purchase of new switch if this occurs frequently Restart 12/5/2024 12:30 Channel 3 Low Operator Error Instruct operator when to switch ranges Shutdown 12/13/2024 10:17 Channel 3 Low Operator Error Instruct operator when to switch ranges Shutdown

4. Safety Related Corrective Maintenance Table III. Summary of Safety Related Maintenance (1 January 2024 through 31 December 2024)

Safety related Corrective Maintenance Date Performed Description 3/29/2024 Performed SP-1 and adjusted Channel 1 detector voltage to 2.3kv from 2.6 kv.

4/17/2024 Beam Port #3 graphite plug was positioned ~2 inches in north direction back to its original position prior to removing the graphite on 4/16/2024.

5/23/2024 Replaced light bulb for Period Trip Indicator due to bulb failure.

6/4/2024 Removed and inspected all CRDMs due to water leaking from existing shield tank leak migrating to area above control rods.

6/17/2024 Placed absorbent mat above CRDMs and a fan was placed in skirt to evaporate any potential water from shield tank leak.

Idaho State University AGN-201m Reactor 2024 Annual Report Page 6 of 8 8/8/2024 Performed rod clearance and interference test on CCR due to CCR not moving at expected rate. Possibly caused by construction activities shaking the structure and causing CCR to become misaligned.

5. Modifications A. Changes in Facility Design - Issuance of Amendment NO. 8 to Renewed Facility License NO. R-110 and implementation of ISU-50.59-2024-1 Soft Shutdown.

B. Changes to Procedures OP-1 and OP-2 were updated to include soft shutdown as the preferred method for reactor shutdown.

C. Changes to Experiments - None D. Reactor Safety Committee At the end of the reporting period, membership of the Reactor Safety Committee (RSC) consisted of the following individuals:

Kermit Bunde - Chair (DOE-ID)

Mary Lou Dunzik-Gougar, PhD - Reactor Administrator (Assoc. Dean, ISU)

Larry Foulkrod - Reactor Supervisor Mason Jaussi - Radiation Safety Officer Kelly Zimmer (INL)

Jay F. Kunze, PhD, PE, CHP (Emeritus Prof., ISU)

Benjamin Baker, PhD (INL)

Jason Andrus, PE (INL)

6. Summary of Changes Subject to 10 CFR 50.59 Analyses -

ISU-50.59-2024-1 allows control rods to be lowered from the reactor using the drive motors (soft shutdown) to minimize the mechanical forces imposed on the control rods from a reactor scram.

Radioactive Effluents A. Liquid Waste - Total Activity Released - None B. Gaseous Waste - Total Estimated Activity Released The AGN-201 Reactor was operated for 146.0397 Watt-hours at power levels up to approximately 4.5 Watts. At this power level Ar-41 production is negligible and substantially below the effluent concentration limit given in 10 CFR 20 Appendix B,

Idaho State University AGN-201m Reactor 2024 Annual Report Page 7 of 8 Table 2. The total activity of Ar-41 released to the environment was conservatively estimated at 3.0317 µCi using Equation (2). This activity corresponds to the total activity of all gaseous radioactive effluent from the facility. A monthly summary of calculated gaseous releases is given in Table IV.

Table IV. Summary of Monthly Gaseous Radioactive Effluent Releases (1 January 2024 through 31 December 2024)

Year Totals Ar-41 January 0.2705

µCi February 0.3606

µCi March 0.5038

µCi April 0.3081

µCi May 0.7512

µCi June 0.000

µCi July 0.0567

µCi August 0.1289

µCi September 0.3270

µCi October 0.0005

µCi November 0.0274

µCi December 0.2970

µCi Total 3.0317

µCi C. Solid Waste - Total Activity - None

7. Environmental Radiation survey One environmental radiation survey was completed in 2024, it was performed on 09/25/2024.

8. Radiation Exposure The Radiation Safety Officer reviews personnel Radiation exposure quarterly. Annual reports of ionizing radiation doses are provided by the Radiation Safety Officer to all monitored personnel as specified in Section 15.4 of the ISU Radiation Safety Manual. Personnel are issued dosimeters by the Radiation Safety Department if they meet the criteria of Section 15.1 of the ISU Radiation Safety Manual. All monitored personnel were below dose limits for calendar year 2024.

() =

(.)()(

)

(.

)

(2)

Idaho State University AGN-201m Reactor 2024 Annual Report Page 8 of 8 The 10 CFR 20.1201 occupational dose limits to adults are: total 5 rem, lens of eye 15 rem, shallow 50 rem, and deep 50 rem. The doses received for all reactor laboratory personnel during 2024 are well below the dose limits of 10 CFR 20.1201, and well below ISU ALARA limits (1 rem per year, 0.3 rem per quarter).

Table VI. Summary of Whole-Body Exposures to the Public (1 January 2024 through 31 December 2024)

None of the 265 visitors to the facility during 2022 received a measurable dose that would exceed the annual 0.1 rem dose limit of 10 CFR 20.1301 for members of the public.

Therefore, the average and maximum doses received by the personnel and the public are within NRC guidelines.

Report Prepared by:

Larry Foulkrod AGN-201m Reactor Supervisor Completed: March 03, 2025 Reviewed and Approved by:

Larry Foulkrod Dr. Mary Lou Dunzik-Gougar AGN-201m Reactor Supervisor AGN-201m Reactor Administrator Completed: March 3, 2025 Completed: April 25, 2025 265 Total Number of Individuals Reported:

• Below 1.0 mrem is considered un-measurable

• • When a dosimeter is dropped, the value indicated is altered from the true value. All individuals who dropped dosimeters are assumed to have no observable dose.

10.0 mrem < Dose < 15.0 mrem Dropped Dosimeter**

259 2

4 0

0 0

5.0 mrem < Dose < 10.0 mrem Estimated Whole-Body Exposure Range (mrem):

Number of Individuals in Each No Observable Dose 1.0 mrem*

1.0 mrem < Dose < 5.0 mrem