ML23055B137

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Submittal of Annual Operating Report for the University of Missouri-Columbia Research Reactor as Required by MURR Technical Specification 6.6.e
ML23055B137
Person / Time
Site: University of Missouri-Columbia
Issue date: 02/24/2023
From: Astrino R, Sanford M
Univ of Missouri - Columbia
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML23055B137 (1)
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1513 Research Park Drive Columbia, MO 65211-3400 Phone: 573.882.4211 Web: murr.missouri.edu February 24, 2023 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001

REFERENCE:

Docket 50-186 University of Missouri-Columbia Research Reactor Renewed Facility Operating License No. R-103

SUBJECT:

Submittal of annual operating report for the University of Missouri-Columbia Research Reactor as required by MURR Technical Specification 6.6.e Enclosed is a copy of the 2022 Reactor Operations Annual Report for the University of Missouri-Columbia Research Reactor (MURR). This document is being submitted to the U.S. Nuclear Regulatory Commission (NRC) in accordance with the MURR Technical Specification 6.6.e.

If you have any questions regarding the contents of this report, please contact Ron Astrino at AstrinoR@missouri.edu or by calling (573) 882-5118.

ENDORSEMENT:

Sincerely, Reviewed and Approved, j l{l~w1r-Ronald M. Astrino Matt Sanford Reactor Manager Interim Reactor Facility Director RMA/jlm Enclosure cc: Mr. Craig Bassett, U.S. NRC Mr. Geoffrey Wertz, U.S. NRC

UNIVERSITY OF MISSOURI-COLUMBIA RESEARCH REACTOR REACTOR OPERATIO NS ANNUAL REPORT January 1, 2022 through December 31, 2022

UNIVERSITY OF MISSOURI-COLUMBIA RESEARCH REACTOR REACTOR OPERATIONS ANNUAL REPORT January 1, 2022 through December 31, 2022 Compiled by the Staff of MURR Submitted by:

Ronald M. Astrino Reactor Manager Reviewed and approved by:

Matt Sanford Interim Reactor Facility Director

UNIVERSITY OF MISSOURI-COLUMBIA RESEARCH REACTOR REACTOR OPERATIONS ANNUAL REPORT January 1, 2022 through December 31, 2022 INTRODUCTION The University of Missouri Research Reactor (MURR) is a multi-disciplinary research and education facility providing a broad range of analytical, materials science, and irradiation services to the research community and the commercial sector. Scientific programs include research in archaeometry, epidemiology, materials science, plant science, nuclear medicine, radiation effects, radioisotope studies, targeted radiotherapy, and nuclear engineering; as well as research techniques including neutron activation analysis, neutron scattering, and gamma-ray imaging. The heart of this facility is a pressurized, graphite and beryllium reflected, open pool-type, light water moderated and cooled, heterogeneous reactor designed for operation at a maximum steady-state power level of 10 Megawatts thermal

- the highest-powered university-operated research reactor in the United States.

The Reactor Operations Annual Report presents a summary of reactor operating experience for calendar year 2022.

Included within this report are changes to MURR Reactor Operations and Reactor Health Physics procedures, revisions to the Safety Analysis Report (SAR), facility modifications, new tests and experiments, reactor physics activities, and environmental and health physics data.

This report is being submitted to the U.S. Nuclear Regulatory Commission (NRC) to meet the administrative requirements of MURR Technical Specification 6.6.e.

ACKNOWLEDGMENTS The success of MURR and its scientific programs is due to the dedication and hard work of many individuals and organizations. Included within this group are: the University of Missouri (MU) administration; the governing officials of the State of Missouri; the Missouri State Highway Patrol (MSHP); the City of Columbia Police Department (CPD);

the University of Missouri Police Department (MUPD) ; the Federal Bureau of Investigation (FBI) ; our regulators; those who have provided funding , including the Department of Energy (DOE), the National Nuclear Security Administration (NNSA), the National Science Foundation (NSF), and the NRC; Argonne National Laboratory (ANL) ;

Idaho National Laboratory (INL) ; Sandia National Laboratories (SNL); the researchers; the students; the Columbia Fire Department (CFD) ; the MU Campus Facilities organization; the Nuclear Energy Institute (NEI); members of the National Organization of Test, Research and Training Reactors (TRTR); and many others who have made, and will continue to make, key contributions to our overall success. To these individuals and organizations, the staff of MURR wishes to extend its fondest appreciation.

Some of the major facility projects that were supported by Reactor Operations during this past calendar year included:

(1) changing out the beryllium reflector ring (accomplished every 8 years); (2) replacing the majority of secondary coolant system piping in our mechanical equipment room; (3) replacing an actuator on valve 546A, inlet to our in-pool heat exchanger; (4) replacing the 60 degree reflector element with two 30 degree reflector elements; (5) replacing the reactor power calculator with a paperless chart recorder; (7) replacing the reflector differential pressure indication and trip module; (8) a Type B radioactive waste shipment; and (9) replacing the facilities main air receiver tank and associated controls.

The facility continues to actively collaborate with the NNSA Office of Material Management and Minimization (M 3)

Reactor Conversion Program and five other U.S. high-performance research and test reactor facilities , including one critical facility, that use highly enriched uranium (HEU) fuel to find a suitable low-enriched uranium (LEU) fuel replacement. Although each one of the five high-performance reactors is responsible for its own feasibility and safety studies, regulatory interactions, fuel procurement, and conversion, there are common interests and activities among all five reactors that will benefit from a coordinated, working-group effort. This past year, work focused on: (1) LEU fuel element fabrication specification impact assessment analyses, which evaluates the effect of fabrication parameter variations on key characteristics of fuel performance; (2) Design Demonstration Element (DDE), one without uranium and one with uranium, that will be flow tested at the Oregon State University Hydro-Mechanical Fuel Testing Facility and inserted into an experimental position at the INL Advanced Test Reactor to achieve prototypic MURR operating conditions; (3) LEU and DDE end fitting rigidity analysis to ensure the DDE test results are representative of the LEU element behavior, current results show no significant difference in response to the loads between the two elements; and (4) LEU preliminary design verification for thermal hydraulics, as well as LEU structural and fluid structure interaction (FSI) analysis are currently underway.

Reactor Operations management also wishes to commend three individuals who received their Reactor Operator certification and one individual who received their Senior Reactor Operator certification from the NRC. These individuals participated in a rigorous training program of classroom seminars, self-study, and on-the-job training. The results of this training are confident, well-versed, decisive individuals capable of performing the duties of licensed staff during normal and abnormal situations.

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TABLE OF CONTENTS Section Pages I. Reactor Operations Summary ............................................................................................... 1-1 through 8 II. MURR Procedures ........................................................... ....... ...... ............ ... .. .. ............ ........ 11-1 through 5 A. Changes to Reactor Operations Procedures B. Changes to Emergency Plan Implementing Procedures C. Changes to Radiological Control, Byproduct Material Shipping, and Preparation of Byproduct Material for Shipping Procedures III. Revisions to the Safety Analysis Report ............................................................................ III-I through 2 IV. Plant and System Modifications ........................................................................................ IV-1 through 2 V. New Tests and Experiments ................................................................................................. V-1 through 2 VI. Special Nuclear Material and Reactor Physics Activities ................................................................... VI-1 VII. Radioactive Effluent ................................ .. ... ............ ....... ... .............................................. VII-I through 2 Table 1 - Sanitary Sewer Effluent Table 2 - Stack Effluent VIII. Environmental Monitoring and Health Physics Surveys ..... ................ .. ............ ... .. ......... VIII-I through 6 Table 1 - Summary of Environmental Set 99 - Spring 2022 Table 2 - Summary of Environmental Set 100 - Fall 2022 Table 3 - Environmental TLD Summary Table 4 - Number of Facility Radiation and Contamination Surveys IX. Summary of Radiation Exposure to Facility Staff, Experimenters, and Visitors .... .... ... .... ................ .IX-1 111

SECTION I REACTOR OPERATIONS

SUMMARY

January 1, 2022 through December 31 , 2022 The following table and discussion summarize reactor operations during calendar year 2022.

Full Power Full Power Month Full Power Hours Megawatt Days

(% of total time) (% of scheduled*)

January 579.33 242.34 77.87% 87.2 1%

February 591.01 246.35 87.95% 98 .50%

March 677.04 282.17 91.00% 101.92%

April 630.98 262.99 87.64% 98.15%

May 645.92 269.26 86.82% 97.24%

June 652.64 272.17 90.64% 101.52%

July 662.19 276.11 89.00% 99.68%

August 154.73 64.49 37.92% 42.47%

September 610.76 254.70 84.83% 95.01 %

October 634.31 264.37 85.26% 95.49%

November 654.03 272.60 90.84% 101.74%

December 665.70 277.49 89.48% 100.21 %

Total for the Year 7,158.64 2,985.04 84.74% 94.91%

  • MURR is scheduled to average at least 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> of full power operation per week. Total time is the number of hours in the month or year listed.

JANUARY 2022 The reactor operated continuously in January with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, one shutdown for physics measurement, and one unscheduled/unplanned power reduction.

On January 4, with the reactor operating at 10 MW in automatic control mode, an automatic reactor scram was initiated from DPS929. All immediate actions of REP-2, "Reactor Scram" , were completed. REP-3, "Primary Coolant System Low Pressure or Flow Scram", and REP-22, "Emergency Core Cooling Valves 546A & 546 B Open During Reactor Operation" , were referenced for any applicable actions. None of the immediate actions from REP-3 and REP-22 were required due to the momentary and transient nature of the DPS929 trip. The cause of the SCRAM was attributed to a recent replacement of valves 540A/B from a rubber diaphragm valve to smaller diameter globe valves which reduced Primary Coolant System Flow. Due to the dynamic nature of measurements at DPS929, decreased system flow caused a momentary transient to below the trip setpoint, even though total system flow was still above minimum requirements.

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Globe valves 540A/B were replaced with repaired diaphragm valves. The reactor was refueled and pem1ission to take the reactor critical was given by the Reactor Manager. Subsequently the reactor returned to 10 MW operation.

Major maintenance items for the month included: completing Modification Record 20-02 , "Replacement of Primary Coolant Heat Exchanger Outlet Valves 540A and 540B"; replacing Primary Coolant Heat Exchanger Isolation Globe Valves 540A/B with Diaphragm Valves; completing CP-31 , "Calibration of the Eberline Radiation Stack Monitor" ;

replacing the cables and switches for the FIRST device; loading new de-ionizing bed ' S' and placing it on pool coolant system service; and performing reactivity worth measurements in accordance with reactor physics procedures RP-RO-200, "Measurement of Differential Worth of a Shim Control Blade, RTP-1 l(D)" for Control Blade "A", and RP-RO-201 , "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-l 7(B)".

FEBRUARY 2022 The reactor operated continuously in February with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, and one unscheduled/unplanned power reduction.

On February 2, with the reactor operating at 10 MW in automatic control mode, an automatic reactor isolation was initiated from high radiation levels at the Reactor Bridge ARMS detector. All immediate actions of EP-RO-012 ,

"Reactor Isolation", were completed. Notifications were made to health physics management, reactor management, irradiations management, and to the Facility Director. Upon health physics arrival, the HP supervisor, and the LSRO made entry into the containment building and discovered elevated radiation levels throughout the entire building.

Contamination swipes were taken, with no measurable contamination detected. Coolant samples were taken and analyzed from both the pool and primary coolant systems, with no anomalies detected. Multiple types of air samples were taken inside the containment building, and eventually the elevated dose rates were discovered to be from Argon-

41. Air concentrations at the time of the Ar-41 sample were approximately 7E-06 µCi/mL (2.34 DAC) at the reactor bridge area. The decision was made by the Reactor Manager, Facility Director, LSRO and HP supervisor in concurrence to leave the containment building isolated for greater than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to allow for Ar-41 decay before reentering the building for occupation and operation. Indications showed that the Ar-41 originated as a bubble beneath the pool surface. Testing of the pneumatic tube system has ruled out a leak from a p-tube terminal into the pool, allowing the reactor to be returned to operation. The reactor was refueled and permission to take the reactor critical was received from the Reactor Manager. Subsequently the reactor returned to 10 MW operation.

Major maintenance items for the month included: replacing the cables and switches for the FIRST device; performing a zero, span and calibration procedure on reactor inlet temperature element TE-901 A and the reactor outlet temperature element TE-901B ; and replacing the facility North Main Air Compressor motor.

MARCH 2022 The reactor operated continuously in March with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, and one shutdown for physics measurement. There were no unscheduled/unplanned power reductions.

Major maintenance items for the month included: burnishing contacts 3 & 4 of Containment Actuation (Reactor Isolation) System relay 2K2; performing a zero, span and calibration procedure on the Beamport Floor - South Wall ARMS , the Containment Building Exhaust Plenum - No 1 and the Reactor Pool Upper Bridge ALARA (south side)

ARMS; completing CP-29 , "Calibration of the Lab Impex Radiation Stack Monitor"; and performing one reactivity 1-2

worth measurement in accordance with reactor physics procedure RP-RO-201 , "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(8)".

APRIL 2022 The reactor operated continuously in April with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, one shutdown for physics measurement, and one unscheduled/unplanned power reduction. An NRC inspector arrived to perform a routine inspection of the MURR Broad Scope Material License.

On April 4, during a normal reactor startup with the reactor operating in a subcritical condition in manual mode, the operator performing the startup noted control blades had stopped withdrawing. The operator checked indications and noted that the Rod Run-In Trip Actuator Amplifier (T AA) had tripped and engaged the Rod Withdrawal Prohibit Circuit. Immediate actions ofREP-1 , "Scram or Rod Run-In Failure", were completed. Electronic Technicians were brought in to troubleshoot and were able to isolate the failure to the Rod Run-In T AA or the Non-Coincidence Logic Unit (NCLU). The Rod Run-In T AA and NCLU modules were removed and replaced with bench tested and calibrated spares. Permission to restart the reactor was obtained from the Reactor Manager. Subsequently the reactor returned to 10 MW operation.

Major maintenance items for the month included: replacing Nuclear Instrumentation Signal Processor No. 1 fission chamber detector; replacing the Emergency Diesel Generator Alarm Panel; replacing the Primary Coolant Circulation Pump P50 lA; replacing filter cartridges in Pool Coolant Demineralizer System inlet filter housing F-200; replacing the Reactor Pool Bridge ARMS meter and detector assembly; replacing the Rod Run-In NCLU and TAA modules; and performing a reactivity worth measurement in accordance with reactor physics procedure RP-RO-201, "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B)".

MAY 2022 The reactor operated continuously in May with the following exceptions: five shutdowns for scheduled maintenance and/or refueling, two shutdowns for physics measurement, and two unscheduled/unplanned power reductions. An NRC license examiner administered one senior reactor operator and three reactor operator licensing examinations.

On May 9, with the reactor operating at 10 MW in automatic control mode, an automatic reactor scram was initiated due to a momentary loss of normal electrical power. All immediate and subsequent actions of REP-11, "Momentary Loss of Normal ElectriC;al Power", were completed. The University of Missouri power plant confirmed that the breakers feeding Research Park tripped open causing the interruption of normal electrical power. Permission to restart the reactor was given by the Reactor Manager after verifying with the University of Missouri power plant that the breakers feeding Research Park were reset, conditions were stable and power was restored. Subsequently, the reactor returned to 10 MW operation.

On May 30, with the reactor operating at a power level of 10 MW during a reactor startup in manual mode, a High-Power Rod Run-In was received on Power Range Monitor-4 due to the spread of power between the power range channels and a delay of putting the reactor into automatic control mode. Once the rod run-in was received the Lead Senior Reactor Operator took over the controls of the reactor. The rod run-in lowered reactor power to 500 KW at which point the rod run-in was reset. Permission to continue the reactor startup was given by the LSRO, and subsequently the reactor returned to 10 MW operation.

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Major maintenance items for the month included: checking and cleaning the Rod Run-In Relays 1K8 & 1K9 and the SCRAM Relays 2K20 & 2K2 l; replacing Relay 2K2 of the Containment Actuation (Reactor Isolation) System; loading new de-ionization bed ' Y ' into Demineralizer Tank 201 ; and perfom1ing two reactivity worth measurements in accordance with reactor physics procedure RP-RO-201 , "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-l 7(B)".

JUNE 2022 The reactor operated continuously in June with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, and one shutdown for physics measurement. There were no unscheduled/unplanned power reductions.

Major maintenance items for the month included: placing new de-ionization bed 'Y' on pool coolant system service; completing the Annual Facility Emergency Preparedness Drill; replacing the Reactor Plant Make-Up Water Tank (T-301) Digital Pressure Transmitter; and performing two reactivity worth measurements in accordance with reactor physics procedures RP-RO-201 , "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B)", and RP-RO-200, "Measurement of Differential Worth of a Shim Control Blade, RTP-1 l(D)".

JULY 2022 The reactor operated continuously in July with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, one shutdown for physics measurement, and one unscheduled/unplanned power reduction.

On July 28, with the reactor operating at 10 MW in the automatic control mode, a manual rod run-in was initiated due to an experimenter informing the control room of a stuck double boron-shielded rabbit in the pneumatic tube system.

Since the exact location of the rabbit was not readily known, the immediate actions of REP-25 , "Failure of a Rabbit to Return", were completed. Investigation revealed that there was an issue with the p-tube system control box flapper in the fume hood and that the rabbit never ran. Therefore, the pneumatic tube system was secured and all runs in the system suspended until the issue was resolved. The reactor was refueled and permission to take the reactor critical was received from the LSRO. Subsequently, the reactor returned to 10 MW operation.

Major maintenance items for the month included: replacing filter cartridges in Pool Coolant Demineralizer System inlet filter housing F-200 ; replacing the Neutron Flux Monitor - Signal Processor Drawer No. I with the spare Neutron Flux Monitor - Signal Processor Drawer; flooding Beamport 'C' with super demineralized water in preparation for a maintenance outage; removing Primary Coolant Differential Temperature Adder-Subtractor (EP 954), Pool Coolant Differential Temperature Adder-Subtractor (EP 952), Reactor Power Calculator, Pool Coolant and Primary Coolant System Differential Temperature Meters from the Control Room Instrument Panel; installing new Primary Heat Balance Power Calculator Chart Recorder (Digital HMI); performing a zero and span procedure on reactor inlet temperature element TE-901A and the pool outlet temperature element TE-901D as a part of their instrument calibration; completing Modification Record 22-01 , "Reactor Differential Pressure Indication and Trip Modification";

and performing a reactivity worth measurement in accordance with reactor physics procedure RP-RO-201, "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, R TP-17 (B )".

AUGUST 2022 1-4

The reactor operated continuously in August with the following exceptions: two shutdowns for scheduled maintenance and/or refueling, tlu*ee shutdowns for physics measurement, and one unscheduled/unplam1ed shutdown. An NRC inspector performed a reactive security inspection of Reactor Operations due to unesc011ed workers entering a vital area and one nonnally schedule NRC routine inspection of Reactor Operations was conducted.

On August 1, following a nonnal refuel evolution the reactor remained in a shutdown condition for approximately four days. This shutdown time was unplanned but necessary due to debris discovered on top of the core during the core inspection as part of the MURR fuel movement sequence. All of the foreign material present in the core was retrieved and identified as pieces of a ruptured primary coolant system strainer basket. Removing the primary coolant system strainer baskets from their respective strainers revealed that both of the strainer baskets were damaged. One of the strainer baskets had ruptured and the second strainer basket fractured but did not rupture. The Nuclear Regulatory Commission was promptly notified via telephone of this event. Temporary replacement primary coolant system strainer baskets were manufactured and analyzed under 50.59 Screen 22-08, "Primary Coolant System Replacement Strainer", and a letter to file dated August 3, 2022 was filed to Modification Record 73-02, "Modification of Pool & Primary Systems for 10 MW". Additional detailed inspections of the primary coolant system piping were conducted to identify the missing pieces of the ruptured primary coolant system strainer basket that were not present in the reactor core. Pieces of the strainer basket were discovered at the inlets of the primary coolant system heat exchangers and in the primary coolant system demineralizer inlet filters. Following these discoveries, the primary coolant system was run repeatedly with the reactor core defueled in order to re-check for pieces of the ruptured strainer basket. The temporary primary coolant system strainer baskets were also inspected per R2-S l , "Flush Primary Coolant System Strainers", following these system runs no further strainer material was found. Additionally, every fuel element assembly from the July 25 , 2022 core and for the pre-beryllium physics core were inspected and checked for blockages. After these corrective actions were completed permission to startup the reactor was received from the Reactor Manager and subsequently the pre-beryllium physics changeout startup was completed.

On August 7, the MURR began the beryllium reflector replacement which lasted twelve days. Replacing the beryllium reflector is a planned evolution that takes place every eight years and has additional maintenance tasks performed and they are as follows: rebuilding Anti-Siphon Isolation Valves V543A and V543B ; rebuilding In-Pool Heat Exchanger Isolation Valves V546A and V546B; replacing primary coolant system water addition check valves V550C and 550D; performing nondestructive testing on the primary coolant pressure vessel spool piece; and performing a reactivity worth measurement to characterize the new beryllium reflector in accordance with reactor procedure RP-RO-201 ,

"Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B)".

On August 8, the MURR began WP 22-2196, "Secondary Coolant Piping Replacement", which lasted 11 days and involved replacing most of the secondary coolant system piping in the mechanical equipment (Room 114). This planned extended outage of the secondary coolant system was scheduled to occur at the same time as the beryllium reflector replacement. This maintenance was necessary because the secondary coolant system piping, which is composed generally of carbon steel, had begun to show signs of erosion in multiple locations. Several leaks have occurred throughout the years leading up to this beryllium changeout evolution. During the secondary piping replacement, most of the piping changes were "like-for- like" replacements with one exception. The one exception being that the secondary flow orifice for FT912R could not be matched and required a change. MURR is currently in the process of developing flow curves for this flow orifice.

On August 29 , while the reactor was subcritical and in the beginning process of a normal start up before the blade full-in lights had cleared, the reactor experienced an automatic scram from PT 944NB. All immediate actions of REP-3 , "Primary Coolant System Low Pressure or Flow Scram", were completed. The primary coolant system was placed in a normal shutdown lineup in accordance with OP-RO-410, "Primary Coolant System". Reactor Management was called and made aware of the unplanned shutdown. The cause of the scram was originally thought to be air in the primary coolant system. Therefore, all the primary coolant system transmitters were vented in I-5

accordance with SM-RO-110, "Isolating, Restoring, and Venting Reactor Coolant System Transmitters", with one additional step that the face of the transmitters themselves were vented. Following this venting evolution, the primary coolant system was staiied back up but little to no improvement was seen in pressures at the reactor core outlet pressure meters - 944A/B. Reactor management was called again and made aware. Once reactor management was on-site, a plan was developed to test the pressure side of the pressurizer. During this evolution valve 515B , the manual isolation valve for the pressurizer was found to be throttled (approximately 55 to 60% closed) versus full open. This valve was then fully opened, and the primary coolant system was again started back up. The primary coolant system saw no improvement after this valve was fully opened in pressures at the reactor core outlet pressure meters - 944A/B. A plan was implemented to remove the primary coolant system strainers to investigate them to see if there was any debris obstructing flow. During this evolution the primary coolant system strainers had nothing obstructing flow, but they were found to be damaged. Therefore, these damaged strainers were removed. New strainers were fabricated in house under the 50.59 screen process with new material that had similar hole size to the originally installed strainers and mirrored the originally designed strainers. Once these strainers were installed, the primary coolant system was started back up and the pressures in the system returned to historical values. At no time was there a risk of safety as the primary coolant system was operated within the safety system settings. The reactor core outlet pressure meters -

944A/B scrammed the reactor and secured the primary coolant system when it was supposed to on low pressure.

Pern1ission was received to take the reactor critical from the LSRO and subsequently the reactor returned to 10 MW operation.

Major maintenance items for the month included: installing temporary replacement primary coolant system y-strainers; replacing Nuclear Instrumentation Signal Processor No. 1 fission chamber detector; replacing filter cartridges in the Primary Coolant Demineralizer System inlet filter housing F-201 ; installing replacement primary coolant system y-strainers; and performing two reactivity worth measurements in accordance with reactor physics procedures RP-RO-201, "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B)" , as part of benchmarking the reactivity worth of the existing 60 Degree Reflector Element Positions Empty before the GH/IJ Wedge Changeout Sequence, and RP-RO-200, "Measurement of Differential Worth of a Shim Control Blade, RTP-11 (D)", for Control Blade "A".

SEPTEMBER 2022 The reactor operated continuously in September with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, two shutdowns for physics measurements, and six unscheduled/unplanned power reductions. An NRC inspector conducted a scheduled inspection of the Type B Shipment of Spent Fuel Using the BEA Research Reactor Package.

On September 3, with the reactor operating at 10 MW in automatic control mode, the reactor experienced a momentary interruption of normal electrical power. This interruption in normal electrical power turned the secondary coolant system pumps and fans off. Since the reactor did not scram, reactor power was manually lowered by shimming inward with the control rods in gang to maintain primary coolant system temperatures. The secondary coolant system switches for the pumps and fans were cycled to OFF and then back to their original positions and the secondary coolant system came back online. Once the secondary coolant system was back in operation, reactor power was returned to 10 MW and the reactor was placed back into automatic control. Applicable steps of REP-11, "Momentary Loss of Nonna] Electrical Power", and REP-15, "Complete or Partial Loss of Secondary Coolant Flow", were followed during this evolution. The cause of the momentary interruption of power was confirmed by the MU Power Plant to be caused by a high voltage transformer issue on campus.

From September 20 through September 25, the reactor experienced a series of four automatic scrams originating from within the power level interlock circuit. Each time the scram signal was received the immediate actions of REP-2, 1-6

" Reactor Scram", ,-vere completed and the annunciations noted. Even though these PLI scrams had similarities, they all differed slightly as sensed by the scram monitoring system . The differences in indications from the scram monitoring system did not allow for definiti ve troubleshooting as to the root cause of the scrams. The following is a list of items that were completed in efforts to troubleshoot the PLI circuit: burnishing contacts three and four of relay 2K9 ; replacing a failing 24 VDC power supply 2PS4; replacing relays 1K26 and 1Kl3 ; taking voltage readings across several associated relays; venting transmitters DPS929 , PT944A&B to rule out air in the system; and installing an additional monitoring system on several additional locations in the PLI circuit. After each PLI scram, pern1ission was received from the Reactor Manager to restart the reactor and subsequently the reactor returned to 10 MW operation.

Once the additional scram monitoring system was installed the MURR did not have another PLI scram. A definitive root cause as to the nature of these PLI scrams has not been positively identified. Even though these PLI scrams occurred, the reactor was operating in a safe condition and doing exactly what it is designed to do and shut down when an electrical anomaly occurred.

Major maintenance items for the month included: completing Modification Record 13-03 , Addendum 1, "Replacement of the 60 Degree GHIJ Wedge with Individual GH and IJ 30 Degree Wedges"; replacing filter cartridges in Pool Coolant Demineralizer System inlet filter housing F-200; replacing filter cartridges in Primary Coolant Demineralizer System inlet filter housing F-201 ; performing two reactivity measurements in accordance with RP-RO-201, "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-l 7(B)"; and performing four reactivity measurements in accordance with RP-RO-200 , "Measurement of Differential Worth of a Shim Control Blade, RTP-1 l(D)" for Control Blades " A, B, C, and D", in order to determine the new worth values of all four shim control blades.

OCTOBER 2022 The reactor operated continuously in October with the following exceptions: five shutdowns for scheduled maintenance and/or refueling, and one shutdown for physics measurement. There were no unscheduled/unplam1ed power reductions. An NRC inspector arrived at the facility for a routine inspection of Reactor Operations.

Maj or maintenance items for the month included: completing CP-3 8, "Verify I-131 Processing Hot Cells Charcoal Filter Efficiency"; replacing Nuclear Instrumentation Signal Processor No. 2 fission chamber detector; loading new de-ionization bed 'G' into Demineralizer Tank 202 ; completing CP-26, " Calibration of the Lab Impex Radiation Stack Monitor"; performing a zero and span procedure on the Reactor Pool Upper Bridge ALARA Radiation Monitor as part of the instrument calibration; completing the biennial change out of Control Blade ' D' Offset Mechanism ;

performing SM-RO-625 , "Measuring Control Blade Pull Weight and Blade Drop Time with the Test Magnet Assembly, RTP-21 ; performing two reactivity measurements in accordance with reactor physics procedures RP-RO-201 , "Measurement of Reactivity Worth ofFlux Trap Loadings or Individual Samples, RTP-17(B)", and RP-RO-200 ,

"Measurement of Differential Worth of a Shim Control Blade, RTP-1 l(D)" on the Regulating Blade".

NOVEMBER 2022 The reactor operated continuously in November with the following exceptions: four shutdowns for scheduled maintenance and/or refueling and two shutdowns for physics measurements. There were no unscheduled/unplanned power reductions.

Major maintenance items for the month included: replacing the Wide Range Neutron Flux Monitor compensated ion chamber; replacing the Reactor Control Console Intercommunication System Master Station; placing new de-ionization bed ' G' on pool coolant system service; replacing Truck entry Dorr 101 air regulator; performing a zero and span procedure on Secondary Coolant System flow transmitter FT912P as part of the instrument calibration; I-7

perforn1ing a zero and span procedure on Primary Coolant Demineralizer flow transmitter FT912B as part of the instrument calibration; and performing two reactivity worth measurements in accordance with reactor physics procedure RP-RO-201 , "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B)".

DECEMBER 2022 The reactor operated continuously in December with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, and one shutdown for physics measurement. There were no unscheduled/unplanned power reductions.

Major maintenance items for the month included: replacing the valve actuator for the In-Pool Heat Exchanger Isolation Valve 546A; replacing the cooling tower vibration cutout switches on each of the cooling tower fans; replacing the two separate independent high voltage power supplies and the voltage regulator inside the Wide Range Neutron Flux Monitor drawer; replacing filter cartridges in Pool Coolant Demineralizer System inlet filter housing F-200; and performing a reactivity worth measurement in accordance with reactor physics procedure RP-RO-201 , "Measurement of Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B)".

1-8

SECTION II MURR PROCEDURES January 1, 2022 through December 31 , 2022 As required by administrative MURR Technical Specification (TS) 6.6.e(5), this section of the Reactor Operations Annual Report includes a summary of procedure changes. These procedure changes were reviewed by the Reactor Manager or Reactor Health Physics Manager, as applicable, and others to assure compliance with the requirements of 10 CFR 50.59. These procedure changes were also reviewed by the Reactor Safety Procedure Review Subcommittee and/or the Isotope Use Procedure Review Subcommittee of the Reactor Advisory Committee to meet the requirements of TS 6.2.a(2).

A. CHANGES TO REACTOR OPERATIONS PROCEDURES As required by the MURR TS , the Reactor Manager reviewed the Reactor Operations procedures and found them to be adequate for the safe and reliable operation of the facility.

There were 34 revisions issued to the Reactor Operations policies, procedures, and forms. The majority of these revisions were strictly format or editorial in nature. No new procedures or policies were issued, and no procedure was obsoleted. The following is a list of the new, revised, and obsoleted policies, procedures, and forms:

Number Name Rev. Rev. Date Notes AP-RR-005 Security of"For Official Use Only" Information 19 04-Apr-22 Minor Editorial EX-RO-105 Reactor Irradiation Experiments 26 27-Jan-22 Minor Editorial EX-RO-110 Pneumatic Tube System 4 20-May-22 Minor Editorial FB-SH-110 Type B Shipment of Spent Fuel Using the BEA 10 20-May-22 Minor Editorial Research Reactor Package FM-15 10 CFR 50.59 Qualified Reviewers List 27 04-Apr-22 Minor Editorial FM-15 10 CFR 50.59 Qualified Reviewers List 28 23-May-22 Minor Editorial FM-43 Nuclear and Process Data Sheet 31 20-May-22 Minor Editorial FM-43 Nuclear and Process Data Sheet 32 28-Jul-22 Minor Editorial FM-43 Nuclear and Process Data Sheet 33 02-Dec-22 Minor Editorial FM-56 Reactor Routine Patrol 29 28-Jul-22 Minor Editorial IRR-PSO- Scheduling Flux Trap Tubes 12 25-Jan-22 Minor Editorial 100 OP-RO-100 Main Air System 16 28-Jul-22 Minor Editorial OP-RO-100 Main Air System 15 20-May-22 Minor Editorial OP-RO-101 Instrument Air System 15 02-Dec-22 Minor Editorial OP-RO-312 Nuclear Instrumentation Power Range Monitor - 17 28-Jul-22 Minor Editorial Channel 6 OP-RO-330 Nuclear Instrumentation - Wide Range Monitor 14 28-Jul-22 Minor Editorial OP-RO-410 Primary Coolant System 21 28-Jul-22 Minor Editorial OP-RO-410 Primary Coolant System 20 27-Jan-22 Minor Editorial II-1

Number Name Rev. Rev. Date Notes OP-RO-420 Primary and Pool Water Analysis 11 29-Dec-22 Minor Editorial OP-RO-461 Pool Coolant System - One Pump Operation 21 28-Jul-22 Minor Editorial OP-RO-461 Pool Coolant System - One Pump Operation 22 02-Dec-22 Minor Editorial OP-RO-466 Pool Level Control - Pool Coolant System 17 29-Dec-22 Minor Editoriai OP-RO-466 Pool Level Control - Pool Coolant System 16 24-May-22 Minor Editorial OP-RO-530 Demineralized Water Supply System 22 20-May-22 Minor Editorial OP-RO-532 Drain Collection System 14 29-Dec-22 Minor Editorial OP-RO-730 Facility Exhaust System 19 10-Feb-22 Minor Editorial OP-RO-741 Waste Tank System Operation 27 10-Feb-22 Minor Editorial POL-20 Special Nuclear Materials Manual 8 01-Aug-22 Minor Editorial REP-RO-100 Reactor Emergency Procedures 28 25-Jan-22 Minor Editorial RL-89 Fueled Experiment Target Interim Storage Silo 2 07-Dec-22 Minor Editorial RM-RO-405 Reactor Demineralizer System 22 20-May-22 Minor Editorial SM-RO-011 Beryllium Reflector Replacement 10 27-Jul-22 Minor Editorial SM-RO-200 Manual Operation of Airlock Doors 276 and 277 8 24-May-22 Minor Editorial SM-RO-555 Fire Protection System 1 24-May-22 Minor Editorial 11-2

B. CHANGES TO EMERGENCY PLAN IMPLEMENTING PROCEDURES As required by the MURR TS , the Reactor Manager reviewed the Emergency Plan implementing procedures and found them to be adequate for the safe and reliable operation of the facility.

There were 6 revisions issued to the Emergency Plan implementing procedures, forms , and operator aids. All of these revisions were strictly format or editorial in nature. No Emergency Plan implementing procedure, fom1, or operator aide was obsoleted. The following is a list of the revised and obsoleted procedures, forms, and operator aids:

Number Name Rev. Rev. Date Notes EP-RO-002 Emergency Responsibilities 11 02-Aug-22 Minor Editorial EP-RO-012 Reactor Isolation 6 02-Aug-22 Minor Editorial EP-RO-015 Emergency Notifications 21 02-Aug-22 Minor Editorial EP-RO-020 Emergency Equipment Maintenance 8 02-Aug-22 Minor Editorial OA-10 Fire Extinguisher Locations and Types 18 26-Jan-22 Minor Editorial OA-20 Emergency Equipment 30 26-Jan-22 Minor Editorial 11-3

C. CHANGES TO RADIOLOGICAL CONTROL, BYPRODUCT MATERIAL SHIPPING, AND PREPARATION OF BYPRODUCT MATERIAL FOR SHIPPING PROCEDURES As required by the MURR TS , the Reactor Health Physics Manager reviewed the radiological control procedures and the procedures for the preparation for shipping and shipping of byproduct materials.

There were 21 revisions issued to the radiological control, byproduct materials shipping, and preparation for shipping byproduct material policies, procedures, fom1s, and operator aids. The majority of these revisions were strictly format or editorial in nature. Additionally, four new procedures and one new form were issued, while one procedure were obsoleted. The following is a list of the new, revised, and obsoleted procedures, forms, and operator aids:

Number Name Rev. Rev. Date Notes AP-HP-105 Radiation Work Permit 17 28-Jul-22 Minor Editorial AP-PSO-004 Iodine Response Procedures 0 20-Apr-22 Full Review AP-RR-013 Access Authorization Program for Category 1 and/or 8 25-Jan-22 Minor Editorial Category 2 Quantities of Radioactive Material AP-SH-001 Administrative Procedure - Radioactive Material 15 25-Jan-22 Minor Editorial Shipping BPB-SH-019 Packaging of Type B Radioactive Material Using 0 25-Jan-22 Full Review USA/9320/B(U)-96 (MIDUS)

BP-SH-099 Packaging of Type A Radioactive Material Using USA 9 02-Jun-22 Minor Editorial DOT 7A MURR Model 1500 FB-SH-110 Type B Shipment of Spent Fuel Using the BEA 10 20-May-22 Minor Editorial Research Reactor Package FM-137 Type B Qualified Shipper List 36 04-Mar-22 Minor Editorial FM-137 Type B Qualified Shipper List 37 28-Jul-22 Minor Editorial FM-197 Control Checksheet for Packaging of Type B 0 25-Jan-22 Full Review Radioactive Material Using USA/9320/B(U)-96 (MIDUS)

FM-197 Control Checksheet for Packaging of Type B 0 25-Jan-22 Minor Editorial Radioactive Material Using USA/9320/B(U)-96 (MIDUS)

FM-61 Leak Testing Documentation for the MIDUS Type B 0 25-Jan-22 Full Review Shipping Package GMP-PRC- Iodine Response Procedures 0 20-Apr-22 Obsoleted 504 IC-HP-313 Calibration - Eberline PCM-1 Personnel 2 10-Feb-22 Minor Editorial Contamination Monitor IC-HP-364 Calibration - Ludlum Model 3030 Swipe Counter 3 25-Jan-22 Minor Editorial OA-8 Importing Authority Notification for the Netherlands 3 20-May-22 Minor Editorial OA-99 Packaging of Type A Radioactive Material Using USA 4 20-May-22 Minor Editorial DOT 7A MURR Model 1500 QAB-SH-004 Type B Program Vendor Qualification 10 20-May-22 Minor Editorial QAB-SH-008 Training for Type B Shipment Leak Test Performers 7 04-Mar-22 Minor Editorial RCP-PSO- Preparation and Handling of Iodine 1-131 Liquid Spill 1 30-Jun-22 Minor Editorial 040 Kits RL-94-P RL-94 Personnel 1 22-Apr-22 Minor Editorial RP-HP-135 Room 114 Entry - Self Monitored 13 28-Jul-22 Minor Editorial 11-4

Number Name Rev. Rev. Date Notes SV-HP-119 Property Release 15 28-Jul-22 Minor Editorial SV-HP-135 Containment Air - Emergency Remote Sampling 7 29-Jul-22 Minor Editorial WM-SH-115 Iodine-131 Waste Handling 9 l 6-Dec-22 Minor Editorial WM-SH-115 Iodine-13 1 Waste Handling 8 28-Jul-22 Minor Editorial II-5

SECTION III REVISIONS TO THE SAFETY ANALYSIS REPORT January 1, 2022 through December 31, 2022 During calendar year 2022, modifications or changes to the facility occurred that required the following revisions to the SAR, as submitted to the NRC in 2006 for relicensing. The following changes have been reviewed, in accordance with 10 CFR 50.59, by licensed staff and members of the Reactor Safety Subcommittee; determined not to involve a change to the MURR Technical Specifications; and approved by the Reactor Manager.

CHAPTER 4 - REACTOR DESCRIPTION Section 4.2.1.6, Figure 4.4 (page 4-14)

Update Figure 4.4, "MURR Core Loading" CHAPTER 7 - INSTRUMENTATION AND CONTROL Section 7.3.1, Table 7-3 (page 7-14)

Change No. 90, to "Pool Coolant System Flow Recorder and Reflector Region Differential Pressure" Remove No. 97, "Reactor Pool Reflector Region Differential Pressure Meter - PT 917" Section 7.3.1, Figure 7.3 (page 7-16)

Remove Number 97.

Section 7.6.4.2, third paragraph (page 7-48)

Delete: "Differential pressure across the reactor pool reflector is monitored by PT 917. This instrument also initiates a reactor scram, serving as a back-up to the pool low flow scram. The transmitter senses pressure at the hot leg of the pool coolant system near pool coolant isolation valve V509 and provides an input signal to an Alarm Meter Unit.

If pressure increases above or decreases below a predetennined set point, a reactor scram and a "Reflector Hi-Low Diff Pressure Scram" annunciator alarm are initiated. The Alarm Meter Unit opens contacts in the process input string to E3B of the Reactor Safety System NCLUs, thereby interrupting power to the control blade electromagnets.

The Alarm Meter Unit also provides reactor pool reflector differential pressure indication on the instrument panel."

Replace with: "Differential pressure across the reactor pool reflector is monitored by PT 917. This instrument also initiates a reactor scram, serving as a back-up to the pool low flow scram. The transmitter senses pressure at the hot leg of the pool coolant system near pool coolant isolation valve V509 and provides an input signal to a paperless chart recorder and Dual Alarm Unit. If pressure increases above or decreases below a predetermined set point, a reactor scram and a "Reflector Hi-Low Diff Pressure Scram" annunciator alarm are initiated. The Dual Alarm Unit opens contacts in the process input string to E3B of the Reactor Safety System NCLUs, thereby interrupting power to the control blade electromagnets. The paperless chart recorder provides reactor pool reflector differential pressure indication on the instrument panel."

CHAPTER 9 - AUXILIARY SYSTEMS Section 9.14.2 III-1

Delete: "The main air system utilizes two compressors, designated the North and South Main Air Compressors, which supply the majority of the compressed air needs of the reactor facility. Both compressors have a discharge capacity of around 100cfm. The north compressor is set to run as the dedicated air compressor, assuming the majority of the main air system demand. The compressor will automatically start when main air system pressure reduces to approximately 95 psig (655 kPa above atmosphere) and will automatically secure when air system pressure increases to approximately 120 psig (827 kPa above atmosphere). If the main air system pressure drops to approximately 90 psig (621 kPa above atmosphere) , the south compressor will automatically start and run to increase pressure to approximately 105 psig (724 kPa above atmosphere) before securing."

Replace with: "The main air system, utilizes two compressors, designated the North and South Main Air Compressors, which supply the majority of the compressed air needs of the reactor facility. Both compressors have a discharge capacity of around 100 cfm. The two compressors automatically alternate roles between lead and lag unit each time the lead compressor cycles in order to equalize wear. When in the lead role, the compressor will automatically start when main air pressure reduces to a pre-established low setpoint and secure when main air pressure reaches a pre-established upper setpoint. If main air system pressure cannot be kept within this band and continues to lower, the lag compressor will start at a pre-established lower setpoint to aid the lead compressor. This condition also initiates the lag alarm circuit, which generates a local alarm and illuminates a local warning lamp.

The lag compressor will receive a signal to stop at a lower setpoint than the lead as pressure rises. The control system also allows for a manual mode of control for either compressor. When in manual control, the selected compressor will cycle within a pre-established pressure band."

III-2

SECTION IV PLANT AND SYSTEM MODIFICATIONS January 1, 2022 through December 31 , 2022 For each facility modification described below, MURR has on file the safety screen or evaluation, as well as the documentation ofreview, performed pursuant to 10 CFR 50.59.

MODIFICATION RECORD 19-04, ADDENDUM 1 Main Air System Receiver Tank Replacement This addendum to Modification Record 19-04, "Main Air System," documents the replacement of the Main Air Receiver Tank and associated piping, replacement of current safety relief valves, and the addition of flow meters to the main air system. These changes support increased air usage throughout the facility. The replacement tank is rated for a Maximum Allowable Working Pressure (MAWP) of 200 PSI and has a capacity of 240 gallons. This increased pressure allows the normal operating band of the north and south main air compressors to shift to 130 to 170 PSIG.

The increased capacity of the receiver tank and a higher operating band for pressure reduce cycling of the north and south main air compressors, increasing reliability. Two new pressure relief valves are set at a relief pressure of 185 psi on the new main air receiver tank. These valves are installed in parallel, each having its own isolation valve to support operation of the main air system while testing operability of each relief valve. Physical controls are implemented on the isolation of the relief valves for the tank. Upon leaving the main air receiver tank, pressure is regulated to 125 PSIG by two parallel pressure regulators. A pressure relief valve set at 130 PSIG is installed downstream of the pressure relief valve and at each lab quadrant to identify leaks in the system. The flow meter has isolation valves and a bypass valve to support maintenance on the flow meter while maintaining system operability.

MODIFICATION RECORD 13-03, ADDENDUM 1 Replacement of the 60 Degree GHIJ Wedge with Individual GH and IJ 30 Degree Wedges This modification record documents the redesign and replacement of the 60 Degree GHIJ Reflector Element with individual 30 Degree Reflector Elements designated as GH and IJ respectively. The GH Reflector Element contains three one-inch nominal irradiation positions and one three-inch nominal position. The IJ Reflector Element contains three one-inch nominal positions and two two-inch nominal positions. The wedge is primarily constructed of 606 l-T6 Aluminum and nuclear grade 2 graphite. Graphite is used to fill the largest voids within the reflector element cans while small aluminum spacers are used at the inside most radius of the assembly as spacers. Aluminum is used where machining small graphite pieces is not feasible. Each assembly is wrapped in a welded and sealed aluminum can that has been purged with helium and voided of all other gases. The irradiation positions for each reflector element are designated as follows: GH-R-1, S-1, T-1 and R3. IJ - U-1, V-1, W-1, B2, and R2. Multiple MCNP calculations were conducted to evaluate the new reflector elements and the results confirmed the design is acceptable for implementation in the reflector tank. Results of these calculations are attached to this addendum. The reactivities and the fluxes of the new reflector elements and their irradiation positions were verified following installation.

MODIFICATION RECORD 22-01 IV-1

Reflector Differential Pressure Indication and Trip Modification This modification record documents the replacement of Differential Pressure Transmitter PT 917 instrument channel with a newer model (Rosemount 3 l 52ND.) This update replaces the original instrument cham1el with a 4-20mA loop, a vendor recommended replacement for the pressure transmitter, dual alarm unit, and a paperless chart recorder to monitor differential pressure. The previous PT 917-meter relay unit is a Model LFE 195 meter-relay unit. This unit utilized the 10-50mA signal from the Rosemount 115 lDP transmitter to provide indication, annunciation, and actuation of the safety system. Following a Licensee Event Report that resulted from a faulty light bulb replacement, MURR has decided to replace this meter relay unit. Measurement of differential pressure across the reflector is measured by a Rosemount Model 3152ND and utilizes a 4-20mA current loop. Control Room indication were added to a Y okogawa DX 1000 paperless chart recorder that currently displays pool flows. Actuation of the safety system and annunciation are provided by an API 1000G alarm module.

MODIFICATION RECORD 73 LETTER TO FILE (August 3, 2022)

Primary Coolant System Strainer Replacement This letter to file Modification Record 73-02, "l 0MW Piping Mods of Primary & Pool," documents the temporary replacement of the Prinlary Coolant System "Y" strainers. The previous "Y" strainers had a hole size of 0.062 inches and a 37% open area. The replacement strainers have a hole size of 0.045 inches with a 37% open area. The 0.045 inch strainer will be utilized until replacement strainers can be sourced matching the original 0.062 inch fabrication.

IV-2

SECTION V NEW TESTS AND EXPERIMENTS January 1, 2022 through December 31 , 2022 The following new and amended tests or experiments were approved during the calendar year 2022 under a Reactor Utilization Request (RUR):

RUR460,NEW Irradiation of Enriched Ytterbium<1 76 Yb) Metal This RUR authorizes the irradiation of 6.5g (99.4%) enriched ytterbium-176 (Yb-176) in purified, metallic form encapsulated in helium-filled quartz or titanium in the peak thermal neutron flux of the large flux trap tubes of the reactor.

RUR461, NEW Irradiation of Enriched Gadolinium ( 160 Gd) Oxide This RUR authorizes the irradiation of 0.5g (~98%) enriched gadolinium oxide (1 60 Gd2O 3) with the isotopes 155 , 157 Gd not exceeding 1% in abundance, encapsulated in aluminum (primary) and quartz (secondary), in the peak thermal neutron flux of the large flux trap tubes in center test hole position of the reactor.

RUR 461, AS AMENDED Enriched Gadolinium (1 60 Gd) Oxide Irradiation This RUR amendment authorizes the change whereby (~98 %) enriched gadolinium-160 oxide (1 60 Gd2O3), which is currently analyzed for irradiation in a flame-sealed 6 mm x 8 mm x 50 mm, synthetic-fused quartz vial, is switched to a smaller 4 mm x 6 mm x 3 8 mm vial for better reactor space utilization.

RUR462,NEW Irradiation of Deuterium-Impregnated Zirconium Foil This RUR authorizes the irradiation, in the reactor reflector K-2 position at a maximum neutron flux of 6.6E+ 13 n/cm2s, of a 53-mg zirconium (Zr) foil impregnated with 5.3 mg of deuterium (2H) suspended in a small stainless steel (SS) capsule. The loaded SS capsule is further inserted and sealed into a specialized larger aluminum and SS external tube 10 inches in total length. The experiment done by Sandia National Laboratory studies the radiation effects on the equilibrium vapor pressure of deuterium.

V-1

RUR 462, AMENDED Irradiation of Deuterium-Impregnated Zirconium Foil This RUR amendment authorizes the change in the reflector irradiation location of the Sandia experiment from K-2 to Blue-2 (B-2) to increase the chance of attaining the desired peak target temperature.

RUR463,NEW Irradiation of Boron Nitride Nano Tubes (BNNT)

This RUR authorizes the irradiation of 0.1 grams of boron nitride nanotubes (BNNT), in the reactor reflector position at a maximum neutron flux of I .OE+ 14 n/cm 2s, encapsulated in aluminum (primary) and quartz (secondary), where the quartz encapsulation is adequately wrapped in aluminum foil to ensure thermal contact with the inner surface of the aluminum encapsulation.

Each of these tests or experiments, new or amended, has a written safety evaluation on file and a 10 CFR 50.59 Screen, if applicable, to assure that the test or experiment is safe and within the limits of MURR Technical Specifications. The safety evaluations have been reviewed by the Reactor Manager, Reactor Health Physics Manager, Assistant Reactor Manager-Physics, and the Reactor Safety Subcommittee, as applicable.

V-2

SECTION VJ SPECIAL NUCLEAR MATERIAL AND REACTOR PHYSICS ACTIVITIES January 1, 2022 through December 31 , 2022 INSPECTIONS The U.S. Nuclear Regulatory Commission (NRC) conducted one routine inspection reviewing special nuclear material (SNM) activities during calendar year 2022. All records and activities were found to be in compliance with NRC rules and regulations. No violations were noted.

REACTOR CHARACTERISTICS MEASUREMENTS Fifty-six refueling evolutions were completed in 2022. Reactor core excess reactivity verifications were performed for each refueling. The largest measured excess reactivity was 2.89%. MURR Technical Specification (TS) 3.1.a requires reactor core excess reactivity above reference core condition to be less than 9 .8%.

REACTIVITY MEASUREMENTS Ten differential blade-worth measurements of the shim control blades were performed either following a planned replacement of a control blade or to ensure compliance with TS 4.2.g.

Five reactivity measurements were perfom1ed to estimate the total reactivity worth of the center test hole removable experiment sample canister, in addition to all samples loaded in the center test hole region of the reactor.

Six reactivity measurements were performed to estimate the worth of various samples that are irradiated in the center test hole region of the reactor. Additionally, one reactivity measurement was performed to estimate the worth of the new beryllium reflector ring, and another to estimate the worth of a new graphite reflector wedge.

VI-1

SECTION VII RADIOACTIVE EFFLUENT January I , 2022 through December 31 , 2022 TABLE 1 SANITARY SEWER EFFLUENT Descending Order of Activity Released for Nuclide Totals > l .000E-02 mCi Nuclide Activity (mCi)

H3 ' 2.70E+02 S35 -- --

2.83E+00 Co60 l.93E+00 --- - -

Lul77 9.59E-0l Ca45 l.58E-01 -

Zn65 8.20E-02 P32 5.00E-02 Gdl59 3.30E-02 Lul77m 2.70E-02 Wl81 --

l.70E-02 Sc46 -

l.60E-02 Gdl53 - -

1.30E-02 Tc99m - -*

l .20E-02 Mo99 l.I0E-02 Total H-3 2.70E+02 Total Other 6.14E+00 Sanitary sewer effluents are in compliance with IO CFR 20.2003, "Disposal by Release into Sanitary Sewerage."

VII-1

TABLE2 ST ACK EFFLUENT Ordered by% Technical Specification Limit Average Concentration Total Release Isotope TS Limit Multiplier %TS

( Ci/ml) ( Ci)

Ar41 l.90E-06 8.80E+08 350 54.1714 1131 2.36E-12 l.09E+03 1.1786 t -_ H_3_ - ~ - - 2.27E-0_8_ __ 1.05E+07 350 0.0649 Xel3lm l.53E-07 7.10E+07 350 0.0219 C-14* l.72E-ll 7.71E-03 -----

0.0057 Osl91 l.78E-ll 8.26E+00 0.0009

__ Rel_86 __ j __ 5.44E-13 _ _________ 2.53E+02 __ -~- __ _ 350 0.0001 Br82 l.15E-12 5.35E+02 350 0.0001 H 203 8.08E-l 6 3.75E-0l 0.0001

  • C-14 activity is calculated based on the ratio of argon to nitrogen in the air and the (n, p) reaction cross sections for the activation ofN-14 to C-14.

Isotopes observed at < 0.0001 % Technical Specification (TS) limit are not listed.

Stack Flow Rate= ~30,000 cfm Stack effluent releases are in compliance with University of Missouri-Columbia Research Reactor, Renewed Facility Operating License No. R-103 TS.

VII-2

SECTION VIII ENVIRONMENT AL MONITORING AND HEAL TH PHYSICS SURVEYS January 1, 2022 through December 31 , 2022 Environmental samples are collected two times per year at eight locations and analyzed for radioactivity. Soil and vegetation samples are also taken at each location. Water samples are taken at three locations, while subsurface soil samples are taken at six locations each period. Analytical results are shown in Tables I and 2.

Table 3 lists the radiation doses recorded by the environmental monitors deployed around MURR in 2022. All doses fluctuate around background with the exception of monitor numbers 4, 8, 9, and 45. These monitors are located near a loading dock area where packages containing radioactive material are loaded or traversed prior to being placed on transport vehicles. The doses recorded by these monitors are considered to be the result of exposure to packages in transit. The environmental monitoring program confirms that minimal environmental impact exists from the operation of the MURR facility.

The number of radiation and contamination surveys performed each month is provided in Table 4.

TABLE I

SUMMARY

OF ENVIRONMENTAL SET 101 - SPRING 2022 Detection Limits*

Matrix Alpha Beta Gamma Tritium Vegetation I 2.17 pCilg I 4.93 pCilg 1.37 pCilg 3.68 pCilmL

-- 7- I Soil 0.49 pCilg 1.60 pCilg I 0.52 pCilg NIA Water I 0.00 pCilg I 1.90 pCilg I 183.88 pCilL i 3.68 pCilmL I I Subsurface Soil I 0.00 pCilg I 1.93 pCi/g I 0.50 pCilg NIA Activity Levels - Vegetation Alpha Beta Gamma Tritium Sample (pCi/g) (pCi/g) (pCi/g) (pCilmL)

I I IVIOI I <MDA I 13.32 I <MDA I I <MDA I

2Vl01 I <MDA I 12.28 <MDA <MDA I i 3Vl01 <MDA I 1.03 I

<MDA <MDA

i 4Vl01 I

<MDA I 19.35 <MDA <MDA I I 5Vl01 i <MDA 12.69 <MDA <MDA 6Vl01 <MDA 29.54 I <MDA <MDA 7Vl01 <MDA I 15.19 I

<MDA ' <MDA I I I I IOVI0I I

<MDA i I <MDA I I 19.97 I  ! <MDA VIII-I

TABLE 1 (Cont' d)

SUMMARY

OF ENVIRONMENT AL SET 101 - SPRING 2022 Activity Levels - Soil Alpha Beta Gamma Sample (pCi/g) (pCi/g) (pCi/g) lSlOl 1.11 15.19 2.50 2S101 0.52 10.92 2.79 3S101 1.26 14.77 2.02 4S101 0.81 12.69 3.20 5S101 1.11 14.56 3.23 6S101 <MDA 5.10 1.56 7S 101 0.96 10.30 2.42 lOSl0l  :

1.11 14.36 3.04 Activity Levels - Water Alpha Beta Gamma Tritium Sample (pCi/g) (pCi/g) (pCi/L) (pCi/mL) 4W101 <MDA 2.08 <MDA <MDA 6W101 _...J.

1.61 4.73 <MDA <MDA 10Wl01 0.28 4.91 <MDA <MDA Activity Levels - Subsurface Soil Alpha Beta Gamma Sample (pCi/g) (pCi/g) (pCi/g)

El0l 0.74 15.71 4.08 SlOl 1.03 10.72 3.27

. --- - --- - - ___.__ --+----

SW101 0.89 14.15 I 4.05 WlOl 0.44 12.69 3.46 NlOl 1.62  !

14.25 3.90 NEl0l 1.18 14.56 3.98

  • Gamma and tritium analyses are based on wet weights while alpha and beta are based on dry weights. HPGe spectral analyses were performed on any sample with a gamma activity greater than minimum detectable activity (MDA).

VIII-2

TABLE 2

SUMMARY

OF ENVIRONMENT AL SET 102 - FALL 2022 Detection Limits*

Matrix Alpha Beta Gamma Tritium Vegetation 0.00 pCilg 3.14 pCilg 1.60 pCilg 1.50 pCilmL Soil 0.00 pCilg 1.53 pCilg 0.73 pCilg NIA Water 0.49 pCilg 1.33 pCilg 245.18 pCilL 3.18 pCilmL Subsurface Soil 0.63 pCilg 1.65 pCilg 0.55 pCilg NIA Activity Levels - Vegetation Alpha Beta Gamma Tritium Sample (pCilg) (pCi/g) (pCilg) (pCi/mL) 1Vl02 0.55 10.92 <MDA <MDA 2Vl02 0.53 14.19 <MDA <MDA 3Vl02 0.29 5.42 <MDA <MDA 4Vl02 0.86 11.99 <MDA <MDA 5Vl02 0.57 13.86 <MDA <MDA 6Vl02 0.27 11.10 <MDA <MDA 7Vl02 0.27 9.14 <MDA <MDA 10Vl02 <MDA 20.17 <MDA I

<MDA Activity Levels - Soil Alpha Beta Gamma Sample (pCi/g) (pCi/g) (pCilg) 1Sl02 1.20 10.42 4.30 2Sl02 0.50 8.34 2.54 3Sl02 0.73 13.83 3.43 4Sl02 0.71 11.76 3.75 5Sl02 0.64 10.70 4.74 6Sl02 0.41 9.62 3.16 7Sl02 0.91 9.00 3.30 10Sl02 0.24 10.17 3.93 VIII-3

TABLE 2 (Cont'd)

SUMMARY

OF ENVIRONMENTAL SET 102 -FALL 2022 Activity Levels - Water Alpha Beta Gamma Tritium Sample (pCi/g) (pCi/g) (pCi/L) (pCi/mL) 4W102 <MDA 2.24 <MDA <MDA

-*--- -~-- ----------

6W102 <MDA 1.46 <MDA <MDA 10W102 <MDA 2.10 <MDA <MDA Activity Levels - Subsurface Soil Alpha Beta Gamma Sample (pCi/g) (pCi/g) (pCi/g)

E102 . -

1.45 12.21 5.57 S102 0.79 14.92 4.55

- - - - - - - - - - - - - - - - - * - - - - - ~ - - - - - - - - - - - - _______,

SW102 1.20 12.38 4.29 W102 1.13 14.41 5.10 Nl02 0.77 1 13.40 4.95 NE102 1.12 12.87 4.94

  • Gamma and tritium analyses are based on wet weights while alpha and beta are based on dry weights. HPGe spectral analyses were performed on any sample with a gamma activity greater than MDA.

VIII-4

TABLE 3 ENVIRONMENTAL TLD

SUMMARY

Badge Direction from Meters from pt Quarter 2nd Quarter 3 rd Quarter 4 th Quarter Total Number MURR MURR Stack (net mrem) (net mrem) (net mrem) (net mrem) (net mrem) o* Control NIA 34 32 32 31 128 1* Control NIA 30 32 32 31 124 2* Control NIA 29 32 32 31 123 3 w 30 <MDA 4 0 2 6 4 SW 59 11 6 11 35 63 5 ENE 110 <MDA 5 0 <MDA 5 6 NNE 84 2 3 7 22 7 ENE 55 <MDA 4 1 3 8 8 SW 32 13 18 9 8 48 9- SSE 27 21 43 25 27 116 10 NE 139 <MDA 2 <MDA 0 2 11 N 135 <MDA <MDA <MDA <MDA 0 12 NE 284 <MDA -- - - -

2 1 10 13 NNE 305 <MDA 2 NIA 0 2 14 s 168 <MDA 6 2 <MDA 8 15 SSE 74 <MDA 6 2 <MDA 8 16 SE 113 <MDA 0 <MDA 1 17 E 299 <MDA <MDA <MDA <MDA 0 18 NE 453 <MDA <MDA <MDA <MDA 0 19 NE 673 <MDA <MDA <MDA <MDA 0 20 NE 893 <MDA

<MDA <MDA <MDA 0 21 SSE 239 0 4 3 5 12 22 SE 158 <MDA <MDA <MDA <MDA 0 23 NW 89 <MDA 5 1 4 10 24 SSW 308 <MDA 4 1 <MDA 5 25 SSW 435 <MDA 4 0 <MDA 4 26 SSW 365 <MDA <MDA 1 2 27 SW 170 <MDA <MDA <MDA <MDA 0 28 NW 229 1 6 -

3 2 12 29 NW 260 <MDA 5 <MDA <MDA 5 30 N 335 <MDA <MDA <MDA <MDA 0 31 NNE 677 <MDA 2 1 2 5

32 NW 760 <MDA -

6

-- --- ~ - -

2 9 33 ESE 578 <MDA <MDA <MDA <MDA 0 34 ENE 596 <MDfi.__ ~ <MDA <MDA <MDA

-*-- -- 0 35 SSE 477 2 12 2 10 26 36 SE 446 <MDA 3 <MDA <MDA 3 37 NE 732 NIA <MDA <MDA <MDA 0 38 NW 487 <MDA -

4- - - - ~ - 4 <MDA 8 39 w 528 <MDA 3 0 -

<MDA 3 40

  • ---- - - - - -- .J-N 503 -'

<MDA

<MDA 2

41 NE 161 <MDA 0 0

<MDA

- ----- -~

0 42 ~- _ In Building ____ NI A _ "-- 1 ______ l~ -- ___J _____ __2_ ~ n__ __ _

__ 43 __ In Buildil~g _ _ NI A_ <MDA -

5 ---

2 3 10 44 SW 102 <MDA 6- - - -------

2 3 11 45 SE -----

94 4 19 -

10 - -

14 47 46 SE 105 2 16 0 NIA 18

  • The control monitors are approximately 10 miles NW of MURR, and gross values are shown.

NI A = badges that were missing during read period (likely lost due to weather), 0 added to total for all NIAs.

VIII-5

TABLE4 NUMBER OF FACILITY RADIATION AND CONTAMINATION SURVEYS Receipt of Surface Radiation Month Radiation Air Samples ** Radioactive Contamination

  • Work Permits Materials January 118 118 44 17 5 February 110 110 40 13 7 March 101 101 52 I 10 8 April 121 121 43 22 16 May 111 111 45 17 17

- *----- *------- -i I

June 108 108 50 16 11 r-July 109 109 46 18 10 August 101 101 34 18 12 September 92 92 35 15 6 October 108 108 41 22 12 November 106 106 43 12 13

- - - - - - - - - - - - --* - -*- -*------- -------~ --

December 102 102 41 19 5 TOTAL 1,287 1,287 514 199 122

  • In addition, general building contamination surveys are conducted each normal working day.
    • Air samples include stack Ar-41, containment Ar-41, sump entries, and hot cell entries.

Miscellaneous Note During calendar year 2022, MURR shipped 1,706 cubic feet of low-level radioactive waste containing 5,920 mCi of activity. Additionally, MURR shipped a high activity shipment of 36 cubic feet containing 150,636 mCi of activity.

VIII-6

SECTION IX

SUMMARY

OF RADIATION EXPOSURE TO FACILITY STAFF, EXPERIMENTERS, AND VISITORS January 1, 2022 through December 31 , 2022 Total Personnel Dose (mrem) by Dosimetry Group BCS DO FOE HP IRR NA NS NSP OPS PRD QA RES RP SH TEE Total January 17 10 68 285 203 41 17 157 1,449 196 123 15 28 128 13 2,750 February 8 12 36 324 169 20 8 121 979 192 126 8 20 105 12 2,140 March 4 9 21 443 202 0 3 197 917 232 131 3 41 76 4 2,283 April 0 0 90 266 146 2 6 151 1,188 186 128 0 25 88 0 2,276 May 0 4 32 313 140 5 8 103 1,125 150 61 5 15 61 0 2,022 June 0 0 34 217 166 12 5 80 712 157 145 12 15 68 7 1,630 July 0 0 69 321 180 2 1 98 897 165 4 0 35 70 0 1,842 August 0 0 203 481 82 0 8 30 6,071 79 18 0 4 68 0 7,044 September 1 0 45 178 121 3 11 100 922 138 41 0 2 96 0 1,658 October 0 0 145 198 166 6 6 186 994 132 68 0 1 39 0 1,941

~

November December 0

0 0

0 10 3

211 235 188 157 4

1 17 3

112 77 686 858 228 195 80 126 0

0 11 3

105 48 0

0 1,652 1,706 Total for Year 30 35 756 3,472 1,920 96 93 1,412 16,798 2,050 1,051 43 200 952 36 28,944 Monthly Average 3 3 63 289 160 8 8 118 1,400 171 88 4 17 79 3 2,412 HighestWB 34 9 135 643 277 15 16 153 848 157 146 12 28 114 9 (annual)

High Extremity 488 NM 1,184 1,065 496 1,160 134 936 1,243 6,717 1,730 12 495 201 132 (annual)

BCS-Business & Central Services HP-Health Physics NSP-NorthS tar Partners RES-Research DO-Director's Office IRR-Irradiations OPS-Operations RP-Radiopharmaceutical FOE-Facilities Operations & Engineering NA-Neutron Activation PRD-Production SH-Shipping NS-Neutron Scattering QA-Quality Assurance TEE-Trace Elemental Epidemiology WB-Whole Body NM-Not Monitored OB-Obsolete TR-Transfer to New Group Analysis of personnel exposure levels indicates that exposures are significantly below the limits of 10 CFR 20.1201 and are generally maintained ALARA.

No significant personnel exposures occurred during this monitoring year.

Dosimetry services are provided by Mirion Technologies & Landauer (transition from Mirion to Landauer in first quarter 2023) (except self-reading dosimetry).

Data for August shows increase in dose for multiple groups as the result of the every 8 year scheduled Beryllium changeout.

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