ML24059A441

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Univ. of Missouri - Columbia - Submittal of Annual Operating Report Technical Specification 6.6.e
ML24059A441
Person / Time
Site: University of Missouri-Columbia
Issue date: 02/28/2024
From: Astrino R, Sanford M
Univ of Missouri - Columbia
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML24059A441 (1)
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Text

UNIVERSITY OF MISSOURI-COLUMBIA RESEARCH REACTOR

REACTOR OPERATIONS ANNUAL REPORT

January 1, 2023 through December 31, 2023

UNIVERSITY OF MISSOURI-COLUMBIA RESEARCH REACTOR

REACTOR OPERATIONS ANNUAL REPORT

January 1, 2023 through December 31, 2023

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 the 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 2023.

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 its 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 include:

(1) replacement of the Primary Coolant Pump P501-B motor; (2) replacement of the detector and cabling on the Wide Range Monitor Channel; (3) replacement of the Signal Processor #2 detector and cabling; (4) replacement of the Pool Coolant Pump P-508B motor; (5) replacement of Pool Coolant Pump P-508A; (7) replacement of Primary Coolant System Heat Exchanger Outlet Valve 540A diaphragm.

i 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 showing 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, which is currently underway.

Reactor Operations management also wishes to commend four individuals who received their Reactor Operator certification and seven 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.

ii TABLE OF CONTENTS

Section Title Pages

I. Reactor Operations Summary............................................................................................... I-1 through 8

II. MURR Procedures...............................................................................................................II-1 through 6 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-1 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-1 through 2 Table 1 Sanitary Sewer Effluent Table 2 Stack Effluent

VIII. Environmental Monitoring and Health Physics Surveys................................................. VIII-1 through 6 Table 1 Summary of Environmental Set 103 - Spring 2023 Table 2 Summary of Environmental Set 104 - Fall 2023 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

iii SECTION I

REACTOR OPERATIONS

SUMMARY

January 1, 2023 through December 31, 2023

The following table and discussion summarize reactor operations during calendar year 2023.

Month Full Power Hours Megawatt Days Full Power Full Power

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

January 642.85 267.96 86.40% 96.77%

February 581.99 242.67 86.61% 97.00%

March 652.60 272.14 87.72% 98.24%

April 617.93 257.69 85.82% 96.12%

May 643.35 268.20 86.47% 96.85%

June 632.86 263.80 87.90% 98.44%

July 646.28 269.41 89.76% 100.53%

August 667.44 278.27 89.71% 100.47%

September 629.61 262.46 87.45% 97.94%

October 639.04 266.38 85.89% 96.20%

November 633.34 263.99 87.96% 98.52%

December 665.90 277.58 89.50% 100.24%

Total for the Year 7,653.19 3,190.55 87.61% 98.12%

  • 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 2023

The reactor operated continuously in January with the following exceptions: five 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: performing a zero, span and calibration procedure on the pool outlet temperature element TE-901D; replacing the Primary Coolant Pump P-501B motor; completing CP-38, -131 Processing Hot Cells Charcoal Filter Efficiency;-31, ;

and performing reactivity worth measurements in accordance with reactor physics procedures RP-RO-200,

- B and RP-RO-201, dings or Individual Samples, RTP-17(B).

I-1 FEBRUARY 2023

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

On February 11, with the reactor operating at 10 MW in automatic control mode, an automatic reactor scram was initiated from a nuclear instrument anomaly from Signal Processor Drawer #2. Upon receiving the SCRAM, the console watch reactor operator performed all immediate actions of REP-2,,

secondary coolant system. While investigating the cause of the nuclear instrument anomaly, the console watch noted that IRM-3 displayed a power down-spike while PRM-5 had a power up-spike at the same time. The nuclear instrument anomaly immediately cleared, and no other abnormal indications were noted from Signal Processor Drawer #2. Notifications were made to reactor management, the Health Physics Supervisor, the Irradiations Manager, and the Associate Director of Facility Operations. An electronics technician was called in to troubleshoot but was unable to recreate or diagnose the issue. The power supply for Signal Processor Drawer #2 was checked with no abnormalities noted. CP-35B, Nuclear Instrumentation - Signal Processor #2 was completed as post-maintenance testing and was satisfactory without any issues noted. 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.

On February 19, with the reactor operating at 10 MW in automatic control mode, the console watch operator manually scrammed the reactor due to erratic indications on the nuclear instrumentation. Typical operation of the nuclear instruments is that all of the nuclear instruments another. This unplanned shutdown of the reactor was necessary because the wide range monitor (WRM) channel was diverging from the power range monitor (PRM) channels. The console watch operator observed two separate instances where the WRM chart displayed a five percent downward spike in power, while the reactor PRM chart displayed a five and three percent upward spike, respectively, in power. Following these observations, reactor power level returned to its actual value. Reactor management was notified of the erratic indications, and the decision was made to conduct an unplanned power reduction in accordance with MURR operating procedure OP-RO-Shutdown or Power Reduction, to replace the WRM compensated ion chamber detector. An electronics technician and health physics technician were called in to assist reactor operations with the replacement of the compensated ion chamber. Following the replacement of the compensated ion chamber, the detector was response-checked as post-maintenance testing. 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: completing CP-38, -131 Processing Hot Cells Charcoal Filter Efficiency; Beamport -

Demineralizer Tank 201; replacing the wide range neutron flux monitor compensated ion chamber; replacing the drain collection tank pump and motor; replacing the filter cartridges in Pool Coolant Demineralizer System Inlet Filter Housing F-200; and performing reactivity worth measurements in accordance with reactor physics procedure RP-RO-201, -17(B).

MARCH 2023

The reactor operated continuously in March with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, two shutdowns for physics measurements, and three unscheduled/unplanned power reductions.

I-2 On March 13, with the reactor operating at 10 MW in automatic control mode, the reactor experienced an automatic rod run-in with no indications of the cause besides the rod run-in trip actuator amplifier (TAA) being tripped. After approximately two minutes of trying to determine the cause, an on-duty reactor operator initiated a manual scram of the reactor. The LSRO, Assistant Reactor Manager, and Reactor Manager were informed, and an electronics technician was called in to further investigate the rod run-in system. During this investigation, it was discovered that fuse F1 for the rod run-TAA had blown. As a result of this investigation, the blown fuse was discovered to be of the wrong rating according to MURR Print No. -In System. Further investigation by the instrumentation support shop will be necessary to determine when and how the improper fuse was installed. The F1 fuse was replaced with a fuse of the proper rating and the rod run-in TAA was tested satisfactorily. Permission to restart the reactor was obtained by the Reactor Manager and the on-shift LSRO. Subsequently, the reactor returned to 10 MW operation.

On March 22, with the reactor operating at 10 MW in automatic control mode, an automatic reactor scram was received from a nuclear instrument anomaly originating from Signal Processor Drawer #2. All immediate actions of REP-2,

, secondary coolant system was secured. The console watch operator noted that IRM-3 displayed a large power down-spike, and PRM-5 had a power up-spike at the same time. No other abnormal indications were noted. The remaining reactor systems were left as-is for troubleshooting by the electronic technicians. Signal Processor Drawer #2 was replaced with the spare drawer from the instrumentation support shop.

CP-35B, Signal Processor #2, was completed as post-maintenance testing following the SP-2 drawer replacement. 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.

On March 23, with the reactor operating at 10 MW in automatic control mode, an automatic reactor scram was received from a nuclear instrument anomaly originating from Signal Processor Drawer #2. The console watch operator performed all immediate actions of REP-2,, secondary coolant system. The console watch operator noted that IRM-3 displayed a power down-spike while PRM-5 had a power up-spike at the same time. The anomaly immediately cleared, and no other abnormal indications were noted. Reactor management, the Irradiations Manager, and the Health Physics Supervisor were informed. This event mirrored Unscheduled Shutdown Nos. 1378 and 1380. Signal Processor #2 was swapped to the spare amplifier assembly (Signal Processor

  1. 2 had been swapped to the spare drawer on the previous shutdown). CP-35B, Signal Processor #2, was performed for retest of Signal Processor #2 following the replacement of SP#2 amplifier assembly with the spare amplifier assembly. 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 Range Selector Switch 1S2 for the wide range neutron flux monitor; replacing the wide range neutron flux monitor signal processor drawer potentiometer; purging Beamport cover; replacing Nuclear Instrumentation Signal Processor Drawer #2; replacing Nuclear Instrumentation Signal Processor Drawer #2 amplifier assembly; removing and reinstalling Beamport D monochromator for maintenance; completing CP-29, Radiation Stack Monitor; procedures RP-RO-200, -11(D), -RO-201,

-17(B).

APRIL 2023

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

I-3 On April 7, was initiated due to a reduction in primary coolant flow. Both the ON and OFF lights for Primary Coolant Pump 501A were illuminated on the control room instrumentation panel, followed by a loss of electrical power to the pump shortly thereafter. The immediate actions of REP-2, Reactor Scram and REP-3, Primary Coolant System Low Pressure or Low Flow Scram were completed. Reactor Operations shut down the primary and pool coolant systems. While investigating the cause, the LSRO found that the breaker for Pump 501A had a smell of smoke/acrid odor and that the breaker had not tripped. The LSRO manually opened the breaker to minimize the likelihood of a fire. The Acting Reactor Manager, Assistant Reactor Manager of Engineering, Irradiations Manager, and Reactor Facility Director were informed. An electronics technician was called in to investigate the Pump 501A breaker and discovered that the time delay relay had failed causing an electrical short and consequently a 6A fuse had blown. Both the time delay relay and the fuse were replaced. The 501A pump was retested satisfactorily. The reactor was refueled, and permission to take the reactor critical was received from the LSRO. Subsequently, the reactor returned to 10 MW operation.

On April 14, with the reactor operating at 10 MW in automatic control mode, while investigating a spurious Channel 4, 5 or 6 Downscale annunciation, an automatic reactor scram was initiated. However, no scram indication was received on the annunciator, signal processor drawers, or on the scram monitoring system. Additionally, no high-power condition was recorded on the power range chart. The annunciator, rod run-in monitoring system and nuclear instrumentation channel 6 drawer did indicate that a Channel 6 Rod Run-In had occurred. Given the equipment response times and prior operating history, it is suspected that a channel 6 high-power scram signal was received for a short enough duration as to not register on the annunciator, drawer, or scram monitoring system. All immediate actions of REP-2, Reactor Scram were completed. The scram signal was determined to be from the channel 6 uncompensated ion chamber. An electronics technician and health physics technician were called in to assist Reactor Operations personnel with the replacement of the cabling and uncompensated ion chamber. The old uncompensated ion chamber cabling displayed severe degradation and was determined to be the cause of the automatic scram. Post-maintenance testing of the detector was performed during reactor refuel by response checking the detector with a fuel element. Following the refuel, permission to take the reactor critical was received from the Lead Senior Reactor Operator. Subsequently, the reactor returned to 10 MW operation.

Major maintenance items for the month included: completing CP- -131 Processing Hot Cells Charcoal Filter Efficiency; loading new de-No. 200; replacing the time delay relay for Primary Coolant Circulation Pump P501A at Motor Control Center 5; placing de-ioniz coolant system service; transferring primary de-replacing Nuclear Instrumentation Signal Power Range Channel No.6 ion chamber detector; replacing Channel 4 Power Level Scram Relay K19; replacing Channel 5 Power Level Scram Relay K20; replacing Channel 6 Power Level Scram Relay K21; completing offset mechanism ; performing SM-RO-Transfer, or Installation of an Offset Mechanism; reactor physics procedures RP-RO-200, -11(D),

and RP-RO-201, -17(B).

MAY 2023

The reactor operated continuously in May with the following exceptions: four shutdowns for scheduled maintenance and/or refueling, one shutdown for a physics measurement, and one unscheduled/unplanned power reduction. An NRC inspector performed a routine scheduled inspection of Health Physics and Shipping.

On May 22, with the reactor in a shutdown condition as part of the normal maintenance day, the decision was made by reactor management and the LSRO to throttle pool heat exchanger bypass valve S-212 in the closed position to

I-4 combat high pool coolant system temperatures. By throttling Valve S-212, more secondary coolant system flow is directed to pool coolant heat exchanger HX-521. The additional flow to the pool coolant heat exchanger would allow for more heat transfer from the pool coolant system to the secondary coolant system. Following startup of the reactor, after throttling of Valve S-212 was performed, the operating crew noticed that the pool coolant system was colder in temperature than normal. The colder pool temperature was due to over throttling of Valve S-212. A discussion with Reactor management and the operating crew took place about the need to readjust Valve S-212. A plan was developed to reposition Valve S-212 the following day when more staffing would be available. At approximately 0800, on May 23, 2023, a manual scram was initiated in accordance with MURR operating procedure OP-RO-Shutdown or Power Reduction, Valve S-212. Shortly after the reactor was shut down, a health physics technician and reactor operator entered the mechanical equipment room to fully opened Valve S-212. Following the adjustment to Valve S-212, permission to restart the reactor was obtained by the LSRO. Subsequently, the reactor returned to 10 MW operation.

Major maintenance items for the month included: replacing Truck Entry Door 101 sprocket shear pins; replacing Truck Entry Door 101 solenoid-operated three-way valve assembly; replacing the diaphragm for Pool Coolant Circulation Pump P-508B Discharge Gauge Isolation Valve 518-AC; replacing the Automatic Transfer Switch AK-2A-25 circuit; replacing Secondary Coolant System Heat Exchanger Relief Valves S-70 and S-71; and performing two reactivity worth measurements in accordance with reactor physics procedure RP-RO-201, Reactivity Worth of Flux Trap Loadings or Individual Samples, RTP-17(B).

JUNE 2023

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

On June 6, with the reactor operating at 10 MW in the automatic control mode, a manual scram was initiated due to a Secondary Coolant Lo Flow annunciation received. The secondary coolant system pump and fan indications were checked and found to be extinguished. The secondary coolant pumps and fans were subsequently placed in a shutdown lineup.

The immediate actions for REP-2,,

REP-10,, REP-15, Secondary Coolant Flow, The initial investigation revealed a total loss of power at motor control center MCC-1. The University of Missouri power plant was contacted, and no abnormalities were noted on their systems. Campus electricians were dispatched to investigate, while the Reactor Manager, Assistant Reactor Manager of Operations, and the Irradiations Manager were notified. Initial investigation by campus electricians revealed that HPC SW-1 was found tripped. Further investigation, in collaboration with the MURR instrumentation support shop, revealed the ground fault circuit of HPC SW-1 to be faulty. Campus electricians determined that HPC SW-2 has a redundant ground fault circuit, and the faulty circuit on HPC SW-1 was bypassed.

This was confirmed to be up to code by a campus engineer. A load test of all three cooling tower fans running in the fast mode was performed satisfactorily as post-maintenance testing. The reactor was refueled, and permission to take the reactor critical was obtained by the on-shift LSRO. Subsequently, the reactor returned to 10 MW operation.

Major maintenance items for the month included: performing a chemical cleaning of Primary Coolant Heat Exchanger HX-503B; performing chemical cleaning of Primary Coolant Heat Exchanger HX-503A; completing CP-26,

ol Coolant Heat Exchanger HX-521; and performing two reactivity worth measurements in accordance with reactor physics procedures RP-RO-201,

I-5

-17(B), and RP-RO-200, t of Differential Worth of a Shim Control Blade, RTP-D.

JULY 2023

The reactor operated continuously in July with the following exceptions: five shutdowns for scheduled maintenance and/or refueling. There were no unscheduled/unplanned power reductions. An NRC license examiner administered three senior reactor operator and two reactor operator licensing examinations.

Major maintenance items for the month included: completing CP-38, -131 Processing Hot Cells Charcoal Filter Efficiency; -31, ; annual facility emergency preparedness drill; replacing the filter cartridges in Pool Coolant Demineralizer System Inlet Filter Housing F-200; and installing a new silicon monochromator powder spectrum diffractometer.

AUGUST 2023

The reactor operated continuously in August 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: performing a zero and span procedure on Reactor Outlet Temperature Element TE-901B as part of the instrument calibration; completing a lead shielding brick modification experiment; performing a cooling tower peroxide sanitization; replacing the fission product monitor anion resin column; replacing Control -In Relay 1K24; loading new de-No. 202 and placing on pool coolant service; and performing reactivity worth measurements in accordance with reactor physics procedures RP-RO-200, surement of Differential Worth of a Shim Control Blade, RTP-11(D), -RO-201, or Individual Samples, RTP-17(B).

SEPTEMBER 2023

The reactor operated continuously in September with the following exceptions: four shutdowns for scheduled maintenance and/or refueling and two unscheduled/unplanned power reductions. An NRC inspector performed a routine scheduled inspection of Reactor Operations.

On September 13, while the reactor was operating at 10 MW in the automatic control mode, an automatic scram was initiated from a pool loop low flow scram. The scram occurred when the on-service pool pump P-508B short circuited.

Upon receiving the scram signal, the console watch operator performed all applicable steps of REP-2, SCRAM, -16,. The pool coolant system was shut down in accordance with MURR operating procedure OP-RO-461, -One Pump Operation. An operator was dispatched to check the pool pump breaker for P-508B at MCC-5, and the breaker was discovered to be tripped. An electronics technician was contacted to megger the pool coolant pump. The electronics technician reported back to the control room that the pool pump motor had an electrical short and would require replacement. The pool coolant system was shifted from P-508B to P-508A pump use. The reactor was refueled, and permission was obtained from the LSRO to restart the reactor. Subsequently, the reactor returned to 10 MW operation.

I-6 On September 22, with the reactor operating at 10 MW in the automatic control mode, a manual scram was initiated for an unplanned shutdown due to pool pump 508A suspected to be failing. On the first routine patrol of the day, it was observed by a control room operator that one of the coolant pumps in the mechanical equipment room was making an excessive amount of noise. The on-shift LSRO and operations management were informed. Further investigation revealed that the noise was coming from the pool pump 508A. After a short discussion, the decision was made to shut down the reactor and work to get pool pump 508B on-service. As a result of ongoing maintenance on Pool Coolant Pump 508B breaker on MCC-5, 50.59 Screen No. 23-35, Temporary Pool Pump Wiring Change was completed, and the electronics technicians wired Pool Coolant Pump 508B into Pool Pump 508A s breaker on MCC-5. During post-maintenance testing of the pool pump, following the temporary wiring change at MCC-5, it was discovered that Pool Pump 508A was allowing air into the pool coolant system. Therefore, Pool Coolant Pump 508A was isolated at the inlet and outlet of the pump to prevent air intrusion and water from leaking from the mechanical seal while Pool Coolant Pump 508B is on service. The reactor was refueled, and permission to restart the reactor was obtained from the on-shift LSRO. Subsequently, the reactor returned to 10 MW operation.

Major maintenance items for the month included: replacing the fission product monitor cation resin and filter column; replacing the motor for Pool Coolant Circulation Pump P508B; and replacing the scintillation detector for the fission product monitor.

OCTOBER 2023

The reactor operated continuously in October with the following exceptions: five shutdowns for scheduled maintenance and/or refueling and one shutdown for a physics measurement. There were no unscheduled/unplanned power reductions.

Major maintenance items for the month included: replacing the D3 breaker on motor control center #5 for Pool Coolant Circulation Pump P508B; completing CP- -131 Processing Hot Cells Charcoal Filter Efficiency; replacing the cooling fan for the variable speed drive unit for Secondary Coolant Pump #2; replacing the starter relay for the north facility main air compressor; replacing Fuel Element Failure IB-2 Instrument Panel, RDA-5A Sodium Iodide Detector and the ARMS Module in the control room instrument panel; completing Modification Record 23-02,

replacing the cooling fans for the variable speed drive units for Secondary Coolant Pumps #1 and #3; completing CP-ration of the Lab Impex Radiation Stack Monitor; replacing the solenoid for the secondary coolant system blowdown valve; completing the biennial change out of C offset mechanism; performing special maintenance procedure SM-RO-625, 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-200, Shim Control Blade, RTP-11(D), and RP-RO-201, Individual Samples, RTP-..

NOVEMBER 2023

The reactor operated continuously in November 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 the contacts on the alarm module for the Eberline off-gas stack monitor; replacing Master Control Switch 1S1; and performing one reactivity worth measurement in accordance with reactor physics procedure RP-RO-Individual Samples, RTP-17(B).

I-7 DECEMBER 2023

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

On December 2, while the reactor was operating at 10 MW in the automatic control mode, a manual scram was initiated due to Primary Coolant System Heat Exchanger Outlet Valve 540A diaphragm failure. At approximately 1830, the control room received a WP-13 P501 A alarm on the radioactive liquid waste system alarm panel. Shortly after receiving this alarm, the pressurizer started charging slower than normal. Eventually, the pressurizer water level Reactor Operators personnel were dispatched to investigate the status of the mechanical equipment room, which revealed a stream of water coming from Primary Coolant System Heat Exchanger Outlet Valve 540A. The control room operator was directed by the on-shift LSRO to manually scram the reactor and secure the primary coolant system pumps. Reactor management, the on-call electronic technician, Health Physics, and Irradiations personnel were notified of the reactor s status. The Assistant Reactor Manager of Engineering provided a sequence for the replacement of the diaphragm for Primary Coolant Isolation Valve 540A. The electronics technician meggered both the primary coolant pump motors and had nothing to report. After the replacement of the diaphragm, post-maintenance testing was completed satisfactorily by running the primary coolant system. The reactor was refueled, and permission obtained from the on-shift LSRO to restart the reactor. Subsequently, the reactor returned to 10 MW operation.

Major maintenance items for the month included: replacing Primary Coolant System Heat Exchanger HX-503A Outlet Valve 540A diaphragm; performing a zero, span and calibration procedure on Reactor Outlet Temperature Element TE-901B; replacing Master Control Switch 1S1 with the original master control switch; and performing one reactivity worth measurement in accordance with reactor physics procedure RP-RO-Flux Trap Loadings or Individual Samples, RTP-17(B).

I-8 SECTION II

MURR PROCEDURES

January 1, 2023 through December 31, 2023

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 51 revisions issued to the Reactor Operations policies, procedures, and forms. The majority of these revisions were strictly format or editorial in nature. No new documents were issued, while two procedures were obsoleted. The following is a list of the revised and obsoleted procedures, forms, and operator aids:

Number Name Rev. Rev. Date Notes AP-RO-105 MURR Operator Requalification Process 3 09-May-23 Minor Editorial AP-RO-115 Modification Records 14 09-May-23 Minor Editorial AP-RO-130 Crane Operation 11 09-May-23 Minor Editorial AP-RR-003 10 CFR 50.59 Evaluations 16 28-Mar-23 Minor Editorial AP-RR-005 Security of For Official Use Only Information 20 06-Feb-23 Minor Editorial AP-RR-011 Facility Access Process 25 05-Jun-23 Minor Editorial AP-RR-014 On-Site Fingerprinting Program 4 26-Oct-23 Minor Editorial EX-RO-105 Reactor Irradiation Experiments 28 02-Oct-23 Minor Editorial EX-RO-105 Reactor Irradiation Experiments 27 31-May-23 Minor Editorial EX-RO-121 Beamport B Operation 17 09-May-23 Minor Editorial EX-RO-122 Beamport C Operation 18 02-Oct-23 Minor Editorial EX-RO-124 Beamport E Operation 18 03-Feb-23 Minor Editorial EX-RO-125 Beamport F Operation 21 02-Oct-23 Minor Editorial FM-04 Visitor/After-Hours Access Request Form 20 05-Jun-23 Minor Editorial FM-04 Visitor/After-Hours Access Request Form 21 06-Jun-23 Minor Editorial FM-15 10 CFR 50.59 Qualified Reviewers List 29 02-May-23 Minor Editorial FM-56 Reactor Routine Patrol 30 21-Nov-23 Minor Editorial FM-56 Reactor Routine Patrol 31 21-Nov-23 Minor Editorial FM-57 Long Form Startup Checksheet 36 09-May-23 Minor Editorial FM-58 Short Form Startup Checksheet 17 09-May-23 Minor Editorial

II-1 Number Name Rev. Rev. Date Notes FM-90 Personal History Questionnaire (PHQ) and Self-12 13-Mar-23 Minor Editorial Disclosure FM-143 1/M Graph 5 31-May-23 Minor Editorial OA-5 Emergency Air Compressor 11 14-Feb-23 Minor Editorial OP-RO-100 Main Air System 17 02-Oct-23 Minor Editorial OP-RO-211 Reactor Startup Hot 19 20-Jul-20 Obsoleted OP-RO-230 Changing Reactor Power Level 12 31-May-23 Minor Editorial OP-RO-250 In-Pool Fuel Handling 25 06-Feb-23 Minor Editorial OP-RO-311 Nuclear Instrumentation - Signal Processor #2 16 31-May-23 Minor Editorial OP-RO-340 Nuclear Instrumentation Adjustment 14 31-May-23 Minor Editorial OP-RO-350 Reactor Power Calculator Flow Potentiometer 10 25-Jul-17 Obsoleted Adjustment OP-RO-465 Pool Level Control - Skimmer System 13 03-Feb-23 Minor Editorial OP-RO-515 Emergency Air System 14 09-May-23 Minor Editorial OP-RO-516 Valve Operation Air System 14 14-Feb-23 Minor Editorial OP-RO-530 Demineralized Water Supply System 23 03-Feb-23 Minor Editorial OP-RO-531 Primary and Pool Sample Station 16 06-Feb-23 Minor Editorial OP-RO-720 Off-Gas (Stack) Radiation Monitor Operational 17 31-May-23 Minor Editorial Checks RL-89 Fueled Experiment Target Interim Storage Silo 3 28-Sep-23 Minor Editorial RM-RO-405 Reactor Demineralizer System 23 14-Feb-23 Minor Editorial RM-RO-405 Reactor Demineralizer System 24 23-Mar-23 Minor Editorial RM-RO-405 Reactor Demineralizer System 25 24-Mar-23 Minor Editorial RP-RO-200 Measurement of Differential Worth of a Shim 11 09-May-23 Minor Editorial Blade, RTP-11 (D)

RP-RO-202 Measurement of Reactivity Worth of Movable 5 09-May-23 Minor Editorial Samples, RTP-6 SM-RO-110 Isolating, Restoring, and Venting Reactor Coolant 1 01-Feb-23 Minor Editorial System Transmitters SM-RO-110 Isolating, Restoring, and Venting Reactor Coolant 2 15-Jun-23 Minor Editorial System Transmitters SM-RO-200 Manual Operation of Airlock Doors 276 and 277 9 26-Oct-23 Minor Editorial SM-RO-420 Pressurizer Operation - Maintenance & Test 8 30-Mar-23 Minor Editorial SM-RO-500 Replacement of Flux Trap Irradiations Reactivity 4 15-Jun-23 Minor Editorial Safety Trip Support Rig SM-RO-555 Fire Protection System 2 30-Mar-23 Minor Editorial SM-RO-555 Fire Protection System 3 15-Jun-23 Minor Editorial SM-RO-640 Retracting and Reinserting Beamport 'F' Liner 8 15-Jun-23 Minor Editorial SM-RO-661 Pool Coolant Hold-Up Tank Welding Repair 5 15-Jun-23 Minor Editorial Instructions

II-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 two revisions issued to the Emergency Plan implementing procedures. Both of these revisions were strictly format or editorial in nature. No Emergency Plan implementing procedures, forms, or operator aids were obsoleted.

Number Name Rev. Rev. Date Notes EP-RO-004 Fire 11 26-Oct-23 Minor Editorial EP-RO-013 Facility Evacuation 14 6-Nov-23 Minor Editorial

II-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 63 revisions issued to the radiological control, byproduct materials shipping, and preparation for shipping byproduct material policies, procedures, forms, and operator aids. The majority of these revisions were strictly format or editorial in nature. Additionally, no new procedures and no new forms were issued, while one procedure was 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-119 High Radiation Area Access 13 26-Oct-23 Minor Editorial AP-HP-124 Ordering and Assigning Dosimetry 3 11-Mar-20 Obsoleted AP-PSO-004 Iodine Response Procedures 1 14-Feb-23 Minor Editorial AP-PSO-004 Iodine Response Procedures 2 26-Sep-23 Minor Editorial AP-SH-003 Shipping and Receiving Building Receipt and 9 04-Oct-23 Minor Editorial Delivery of Non-Radioactive Freight to MURR BP-SH-014 Packaging Type A Radioactive Material in an 10 14-Feb-23 Minor Editorial Overpack BP-SH-099 Packaging of Type A Radioactive Material Using 10 09-Jan-23 Minor Editorial USA DOT 7A MURR Model 1500 FM-50 Control Checksheet for Type B USA/0820/B(U)-96 2 14-Feb-23 Minor Editorial (F-522 Series) Radioactive Material Shipment FM-79 Lutetium Chloride Radiation Protection Data Sheet 15 26-Oct-23 Minor Editorial B

FM-94 Exclusive Use Shipment Controls 12 08-Jun-23 Minor Editorial FM-137 Type B Qualified Shipper List 38 08-Jun-23 Minor Editorial FM-137 Type B Qualified Shipper List 39 07-Nov-23 Minor Editorial FM-165 Radiation Protection Data Sheet 'A' for cMo-99 7 25-Apr-23 Minor Editorial Process in Hot Cell HC-02A/B FM-165 Radiation Protection Data Sheet 'A' for cMo-99 7 25-Apr-23 Minor Editorial Process in Hot Cell HC-02A/B FM-172 Lutetium Chloride Radiation Protection Data Sheet 2 25-Apr-23 Minor Editorial D

FM-603 NCA Lutetium Lu-177 Chloride Solution Radiation 1 05-Jan-23 Minor Editorial Protection Data Sheet B GMP-PRC-201 Transfer of cGMP Lu-177 Chloride Product to 12 17-Mar-23 Minor Editorial Shipping GMP-PRC-503 Transfer of Sodium Iodide I-131 Product to Shipping 5 13-Mar-23 Minor Editorial GMP-PRC-503 Transfer of Sodium Iodide I-131 Product to Shipping 6 23-Jun-23 Minor Editorial IC-HP-346 Calibration - Lab Impex Smart MCA Continuous Air 9 15-Aug-23 Minor Editorial Monitor IC-HP-361 Calibration - Canberra GEM V Portal Monitor 3 15-Aug-23 Minor Editorial IC-HP-368 Calibration - ALMO-6 Radiation Monitoring 4 13-Feb-23 Minor Editorial Instrument OA-192 Packaging of Type A Radioactive Material Using 1 12-Dec-23 Minor Editorial USA DOT 7A Model MURR MAX

II-4 Number Name Rev. Rev. Date Notes OP-HP-228 Performing Iodine 131 Bioassay Measurements 10 15-Aug-23 Minor Editorial OP-HP-231 Respirator Cleaning and Care 3 27-Jun-23 Minor Editorial OP-HP-232 Respirator Storage, Maintenance and Inspection 3 27-Jun-23 Minor Editorial OP-HP-233 Respirator Fit Test 4 27-Jun-23 Minor Editorial OP-HP-234 Physical Exam for Respirator Program 4 27-Jun-23 Minor Editorial OP-HP-236 Respirator Selection, Issuance, and Wearing 5 27-Jun-23 Minor Editorial OP-HP-300 Receipt of Radioactive Material 15 26-Oct-23 Minor Editorial OP-HP-305 Ordering or Transfer of Radioactive Materials 9 05-Apr-23 Minor Editorial OP-HP-305 Ordering or Transfer of Radioactive Materials 10 12-Oct-23 Minor Editorial OP-HP-306 Health Physics Daily Facility Checks 13 05-Apr-23 Minor Editorial OP-HP-306 Health Physics Daily Facility Checks 14 13-Jun-23 Minor Editorial OP-HP-353 Waste Tank Sample - Analysis 12 15-Aug-23 Minor Editorial OP-HP-353 Waste Tank Sample - Analysis 13 04-Oct-23 Minor Editorial OP-HP-356 Operation - Lab Impex Stack Monitor: Filter Change 10 17-Nov-23 Minor Editorial and Source Checks OP-HP-358 Operation - Lab Impex Smart MCA Continuous Air 4 09-Jan-23 Minor Editorial Monitor Filter Change and Source Check RCP-PSO-025 Selenium-75 Distribution 2 26-Oct-23 Minor Editorial RL-25-P RL-25 Personnel 14 27-Dec-23 Minor Editorial RL-25-P RL-25 Personnel 13 30-Jun-23 Minor Editorial RL-27-P RL-27 Personnel 7 28-Sep-23 Minor Editorial RL-35-P RL-35 Personnel 31 30-Jun-23 Minor Editorial RL-35-P RL-35 Personnel 32 17-Oct-23 Minor Editorial RL-61 PSD Diffractometer at Beamport D 12 30-Jun-23 Minor Editorial RL-70 Thermal Neutron Beam-Line for Neutron Capture 10 28-Sep-23 Minor Editorial Therapy (NCT) on Beam Port E RL-72 cGMP Lu-177 Chloride Processing 16 04-May-23 Full Review RL-72-P RL-72 Personnel 18 27-Dec-23 Minor Editorial RL-73 99Molybdenum (Mo-99) Production (n-Gamma 10 30-Jun-23 Minor Editorial Production)

RL-74 Reflector and Bulk Pool Irradiation for Neutron 6 04-May-23 Minor Editorial Activation Analysis (NAA)

RL-76 Production and Quality Analysis of I-131 8 30-Jun-23 Minor Editorial Radiochemical Sodium Iodide Solution RL-81 Aliquoting of Potassium Molybdate (Mo-99) Final 12 25-Sep-23 Minor Editorial Intermediate RL-81 Aliquoting of Potassium Molybdate (Mo-99) Final 11 04-May-23 Minor Editorial Intermediate RL-81-P RL-81 Personnel 10 04-May-23 Minor Editorial Sample Environment for Pressure Cell with RL-84 Flammable Gases for 2XC (RL-33), PSD (RL-61) 6 27-Dec-23 Minor Editorial and TRIAX (RL-46)

Sample Environment for Pressure Cell with RL-84 Flammable Gases for 2XC (RL-33), PSD (RL-61) 5 04-May-23 Minor Editorial and TRIAX (RL-46)

II-5 Number Name Rev. Rev. Date Notes Gas Handling System for in situ Adsorption RL-88 Measurements for 2XC (RL-33), PSD (RL-61) and 5 28-Sep-23 Minor Editorial TRIAX (RL-46)

RL-89 Fueled Experiment Target Interim Storage Silo 3 28-Sep-23 Minor Editorial RL-89-P RL-89 Personnel 4 28-Sep-23 Minor Editorial RL-94 NCA Lu-177 Processing 4 30-Jun-23 Minor Editorial RL-95-P RL-95 Personnel 1 28-Sep-23 Minor Editorial RP-HP-125 Radiation Monitoring - Performing and 7 01-Aug-23 Minor Editorial Documenting a Survey SV-HP-105 Sealed Calibration Source - Leak Check 11 05-Apr-23 Minor Editorial WM-SH-300 Exclusive Use Shipment of LSA or SCO Radioactive 19 14-Feb-23 Minor Editorial Waste

II-6 SECTION III

REVISIONS TO THE SAFETY ANALYSIS REPORT

January 1, 2023 through December 31, 2023

During calendar year 2023, 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 1 The Facility

Section 1.2, Figure 1.1 (Page 1-5)

Section 1.2, Figure 1.2 (Page 1-6)

CHAPTER 6 Engineered Safety Features

Section 6.2.2.2, Figure 6.1 (Page 6-3)

Section 6.2.3.3, Figure 6.2 (Page 6-8)

Update Figure 6.2

CHAPTER 7 Instrumentation and Control

Section 7.6.2.2, Figure 7.7 (Pages 7-39/40)

Update Figure 7.7, with MURR Print No. 41 Sheet 2/4 revision No.

31 dated 03/01/2023

CHAPTER 8 Electrical Power Systems

Section 8.1.3, Figure 8.1 (Page 8-4)

Update Figure 8.1, with MURR Print No. 2294, Sheet 1/1, Rev. 5 dated 01/05/2023

Section 8.1.3, Figure 8.2 (Pages 8-5/6)

, Print No. 522, Sheet 1/8, Rev. 60 dated 10/27/2023

Section 8.2.8 (Page 8-10)

III-1

, Print No. 522, Sheet 4/8, Rev.

4 dated 09/21/2022

III-2

SECTION IV

PLANT AND SYSTEM MODIFICATIONS

January 1, 2023 through December 31, 2023

For each facility modification described below, MURR has on file the safety screen or evaluation, as well as the documentation of review, performed pursuant to 10 CFR 50.59.

MODIFICATION RECORD 23-01

Regulating Blade Switch Cover The modification record introduces a switch cover for Regulating Blade Switch 1S5 located on the control room console. This cover will prevent the inadvertent manipulation of the 1S5 switch, which places the reactor into the manual control mode. In the past 10 years, there have been two unscheduled shutdowns that were caused by the inadvertent operation of the Switch 1S5. There have been numerous instances where the switch was operated and forced the reactor out of the automatic control mode. The inadvertent operation of the regulating blade switch requires the console operator to manipulate reactor controls to place the reactor back into the automatic control mode. The operator ensures that the following automatic control setpoints are met:

a. reactor period as indicated by Intermediate Range Channels 2 and 3 are greater than 35 seconds,
b. reactor power level greater than the auto control prohibit setpoint on the wide range neutron flux monitor,
c. regulating blade position is greater than 60% withdrawn, and
d. Range Selector Switch 1S2 in the 5-kW red scale position or above.

Regulating Blade Switch 1S5 is located adjacent to Shim Blade Withdrawal-insertion Switch 1S4. This engineered control will greatly reduce the possibility of the inadvertent operation of the regulating blade switch.

MODIFICATION RECORD 88-06, ADDENDUM 2 LETTER TO FILE (May 12, 2023)

Emergency Generator Panel Load Transfer This letter to Modification Record 88-06, Addendum 2:

documents the temporary transfer of electrical power for the emergency power generator (EPG) battery charger from the diesel room panel to the emergency lighting panel (ELP). The charger will be powered by a receptacle off of the ELP until the 15kVA transformer, which supplies the diesel room panel, can be replaced.

MODIFICATION RECORD 23-02

Fuel Element Failure Monitor Calibration Change This modification record documents a change in the calibration methods for the fuel element failure (FEF) monitoring system. The letter from the MURR Assistant Reactor Manager Physics details the change in calibration methodology for this detector and is attached to the modification record.

As part of this modification, the alarm setpoints will be adjusted to effectively provide an indication to the control room operators. At the time of this writing, the new background counts from the detector are showing approximately

IV-1

30-35K counts per minute with the reactor operating. Reactor Health Physics has estimated the approximate rise in counts required to ensure Reactor Operations can respond appropriately to sample the primary coolant system in the event of a sustained rise above the alarm setpoint as defined in REP-RO-and REP-setpoint is attached to the modification record.

IV-2

SECTION V

NEW TESTS AND EXPERIMENTS

January 1, 2023, through December 31, 2023

The following new and amended tests or experiments were approved during the calendar year 2023 under a Reactor Utilization Request (RUR):

RUR 118 and 439, AS AMENDED

Irradiation of Natural Molybdenum and Recycled Molybdenum-98 This RUR amendment authorizes the irradiation of fresh or reclaimed (i.e., recycled) enriched Mo-98 target material from prior irradiation and natural molybdenum at the maximum mass of 480 grams of the target.

RUR 277, AS AMENDED

Irradiation of Natural Strontium and Enriched Strontium-84 and -88 Metals, Oxides, and Carbonates This RUR amendment authorizes the irradiation of 25 milligrams of natural strontium, enriched strontium-84, and -

88 metal, oxide, and carbonate in an aluminum quartz double encapsulation. Under the prior applicable RUR 277 regarding the irradiation of strontium carbonate, there are no complete thermal analyses in RUR 277 safety evaluation regarding irradiating enriched strontium-84 carbonate or strontium-88 carbonate within a quartz aluminum double encapsulation to satisfy the safety analysis.

RUR 455, AS AMENDED

Irradiation of Gallium Nitride and -Gallium Trioxide ( -Ga2O3)

This amendment authorizes the inclusion of up to 100 grams of -gallium trioxide ( -Ga2O3) under RUR 455, which concerns the irradiation of gallium nitride (GaN). Ga 2O3 is, similar to GaN, an inert material, which is insoluble in water. Therefore, all irradiation concerns and protocols outlined in the original RUR 455 for GaN shall apply to Ga2O3.

RUR 461, AS AMENDED

Irradiation of Enriched 160-Gadolinium Oxide 160Gd2O3 This RUR amendment authorizes the mass of enriched 160-gadolinium oxide ( 160Gd2O3) irradiated to be increased from 100mg to 250mg as a stepwise precaution towards safely approaching the maximum mass limit of 500mg. RUR 461 qualifies the irradiation to proceed in specific mass increments of 50mg, 100mg, 250mg, and 500mg of enriched 160Gd2O3.

RUR 463, CORRECTION

Irradiation of Boron Nitride Nanotubes (BNNT)

V-1 This RUR correction pertains to some confusion about the percentage mass distribution in the BNNT target material (BN), which is used to calculate the potential end of radiation activities. The clarification calculations were irrelevant for the safety analysis heating calculations, and all other aspects and conclusions of the RUR, including the safety analysis, will remain unaffected and unchanged.

Each of these tests or experiments, new or amended, have 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 VI

SPECIAL NUCLEAR MATERIAL AND REACTOR PHYSICS ACTIVITIES

January 1, 2023 through December 31, 2023

INSPECTIONS

The U.S. Nuclear Regulatory Commission (NRC) conducted one routine inspection reviewing special nuclear material (SNM) activities during calendar year 2023. All records and activities were found to be in compliance with NRC rules and regulations. No violations were noted.

REACTOR CHARACTERISTICS MEASUREMENTS

Sixty-three refueling evolutions were completed in 2023. Reactor core excess reactivity verifications were performed for each refueling. The largest measured excess reactivity was 3.93%. MURR Technical Specification (TS) 3.1.a requires reactor core excess reactivity above reference core condition to be less than 9.8%.

REACTIVITY MEASUREMENTS

Six 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 performed 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.

Eight 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, while another was performed to estimate the worth of a new graphite reflector wedge.

VI-1 SECTION VII

RADIOACTIVE EFFLUENT

January 1, 2023 through December 31, 2023

TABLE 1 SANITARY SEWER EFFLUENT

Descending Order of Activity Released for Nuclide Totals > 1.000E-02 mCi

Nuclide Activity (mCi)

H-3 4.44E+01 S-35 2.78E+00 Co-60 2.16E+00 Lu-177 4.81E-01 P-32 2.07E-01 Zn-65 1.96E-01 Cr-51 1.46E-01 Ca-45 1.39E-01 Tc-99m 1.19E-01 Sc-46 2.02E-02 Rh-105 1.61E-02 Mo-99 1.26E-02 Total H-3 4.44E+01 Total Other 6.28E+00

Sanitary sewer effluents are in compliance with 10

VII-1 TABLE 2 STACK EFFLUENT

Ordered by % Technical Specification Limit

Isotope Average Concentration Total Release TS Limit Multiplier % TS

(µCi/ml) (µCi)

Ar-41 2.45E-06 1.14E+09 350 70.0624 I-131 1.75E-12 8.15E+02 1 0.8771 H-3 1.50E-08 6.98E+06 350 0.0429 Xe-131m 1.19E-07 5.54E+07 350 0.0170 C-14* 2.23E-11 9.97E-03 1 0.0074 I-128 7.71E-11 3.58E+04 350 0.0001 Re-186 6.01E-13 2.79E+02 350 0.0001 Br-82 1.11E-12 5.17E+02 350 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 of N-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

ENVIRONMENTAL MONITORING AND HEALTH PHYSICS SURVEYS

January 1, 2023 through December 31, 2023

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 1 and 2.

Table 3 lists the radiation doses recorded by the environmental monitors deployed around MURR in 2023. All doses fluctuate around background with the exception of monitor numbers 10, 14, 15, and 51. 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 1

SUMMARY

OF ENVIRONMENTAL SET 103 - SPRING 2023

Detection Limits*

Matrix Alpha Beta Gamma Tritium Vegetation 0.41 pCi/g 1.68 pCi/g 1.57 pCi/g 3.51 pCi/mL Soil 0.00 pCi/g 0.69 pCi/g 0.93 pCi/g N/A Water 0.00 pCi/g 0.67 pCi/g 232.17 pCi/L 4.37 pCi/mL Subsurface Soil 0.13 pCi/g 0.50 pCi/g 0.82 pCi/g N/A

Activity Levels - Vegetation

Sample Alpha Beta Gamma Tritium (pCi/g) (pCi/g) (pCi/g) (pCi/mL) 1V103 <MDA 9.37 <MDA <MDA 2V103 <MDA 13.19 <MDA <MDA 3V103 <MDA 10.71 <MDA <MDA 4V103 <MDA 11.30 1.89 <MDA 5V103 <MDA 10.27 <MDA <MDA 6V103 <MDA 17.24 <MDA <MDA 7V103 <MDA 9.38 <MDA <MDA 10V103 <MDA 11.13 <MDA <MDA

VIII-1 TABLE 1 (

SUMMARY

OF ENVIRONMENTAL SET 103 - SPRING 2023

Activity Levels - Soil

Sample Alpha Beta Gamma (pCi/g) (pCi/g) (pCi/g) 1S103 0.71 14.65 4.03 2S103 0.40 10.55 3.22 3S103 1.03 11.48 3.13 4S103 0.38 11.93 4.45 5S103 0.94 13.67 5.18 6S103 0.25 6.18 2.69 7S103 1.13 11.81 4.04 10S103 0.43 11.59 5.45

Activity Levels - Water

Sample Alpha Beta Gamma Tritium (pCi/g) (pCi/g) (pCi/L) (pCi/mL) 4W103 0.94 9.82 <MDA <MDA 6W103 <MDA 5.56 <MDA <MDA 10W103 0.10 10.82 <MDA <MDA

Activity Levels - Subsurface Soil

Sample Alpha Beta Gamma (pCi/g) (pCi/g) (pCi/g)

E103 0.78 13.29 5.44 S103 1.23 10.97 5.26 SW103 1.59 12.73 5.27 W103 0.37 13.14 5.14 N103 1.73 10.33 4.83 NE103 1.25 9.91 4.76

  • 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 ENVIRONMENTAL SET 104 - FALL 2023

Detection Limits*

Matrix Alpha Beta Gamma Tritium Vegetation 2.34 pCi/g 3.75 pCi/g 1.46 pCi/g 2.89 pCi/mL Soil 1.06 pCi/g 2.17 pCi/g 0.76 pCi/g N/A Water 1.69 pCi/g 3.00 pCi/g 185.50 pCi/L 3.20 pCi/mL Subsurface Soil 0.96 pCi/g 2.06 pCi/g 0.64 pCi/g N/A

Activity Levels - Vegetation

Sample Alpha Beta Gamma Tritium (pCi/g) (pCi/g) (pCi/g) (pCi/mL) 1V104 <MDA 11.69 3.30 <MDA 2V104 <MDA 7.26 1.63 <MDA 3V104 <MDA 4.03 <MDA <MDA 4V104 <MDA 20.51 <MDA <MDA 5V104 <MDA 12.78 <MDA <MDA 6V104 <MDA 11.24 <MDA <MDA 7V104 <MDA 17.76 <MDA <MDA 10V104 <MDA 10.82 <MDA <MDA

Activity Levels - Soil

Sample Alpha Beta Gamma (pCi/g) (pCi/g) (pCi/g) 1S104 1.10 11.26 4.14 2S104 <MDA 13.66 4.58 3S104 <MDA 16.29 2.45 4S104 1.21 10.80 4.23 5S104 <MDA 13.24 5.48 6S104 <MDA 9.65 4.63 7S104 <MDA 10.43 4.26 10S104 1.23 12.45 5.35

VIII-3 TABLE 2 (

SUMMARY

OF ENVIRONMENTAL SET 104 - FALL 2023

Activity Levels - Water

Sample Alpha Beta Gamma Tritium (pCi/g) (pCi/g) (pCi/L) (pCi/mL) 4W104 <MDA 7.50 <MDA <MDA 6W104 <MDA 10.31 <MDA <MDA 10W104 <MDA 5.75 <MDA <MDA

Activity Levels - Subsurface Soil

Sample Alpha Beta Gamma (pCi/g) (pCi/g) (pCi/g)

NE104 <MDA 12.62 4.82 E104 <MDA 14.14 5.11 S104 1.16 12.95 5.44 SW104 <MDA 11.60 4.54 W104 1.16 13.43 5.59 N104 <MDA 13.38 4.72 NW104** <MDA 2.19 2.55

  • 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.
    • New sample for the 2023 Fall due to breaking ground on new MURR West building

VIII-4 TABLE 3 ENVIRONMENTAL TLD

SUMMARY

Badge Direction from Meters from 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Total Number MURR MURR Stack (net mrem) (net mrem) (net mrem) (net mrem) (net mrem) 000 Control N/A* 28 28 28 36 120 9 W 30 3 2 7 3 15 10 SW 59 10 <MDA 63 4 77 11 ENE 110 <MDA 1 8 3 12 12 NNE 84 3 4 11 5 23 13 ENE 55 1 3 4 1 9 14 SW 32 11 11 22 18 62 15 SSE 27 19 24 27 23 93 16 NE 139 1 2 7 1 11 17 N 135 <MDA <MDA 3 <MDA 3 18 NE 284 4 4 9 4 21 19 NNE 305 <MDA <MDA 6 <MDA 6 20 S 168 1 2 9 <MDA 12 21 SSE 74 2 5 9 6 22 22 SE 113 <MDA <MDA 1 <MDA 1 23 E 299 <MDA 6 2 1 9 24 NE 453 <MDA <MDA 3 <MDA 3 25 NE 673 <MDA <MDA 2 <MDA 2 26 NE 893 <MDA <MDA 2 2 ** 4 27 SSE 239 1 1 11 4 17 28 SE 158 <MDA <MDA 0 <MDA 0 29 NW 89 3 3 5** 7 18 30 SSW 308 1 4 10 5 20 31 SSW 435 <MDA <MDA 7 2 9 32 SSW 365 <MDA <MDA 7 1 8 33 SW 170 <MDA <MDA 2 <MDA 2 34 NW 229 6 3 7 6 22 35 NW 260 1 1 6 <MDA 8 36 N 335 <MDA <MDA 3 <MDA 3 37 NNE 677 <MDA <MDA 6 3 9 38 NW 760 3 2 11 2 18 39 ESE 578 <MDA <MDA <MDA <MDA 0 40 ENE 596 <MDA <MDA 1 <MDA 1 41 SSE 477 7 4 15 8 34 42 SE 446 <MDA <MDA 1** 1 2 43 NE 732 2 <MDA 4 <MDA 6 44 NW 487 2 1 7 3 13 45 W 528 <MDA <MDA 6 1 7 46 N 503 <MDA <MDA 4 4** 8 47 NE 161 <MDA <MDA 4 1 5 48 In Building N/A 10 6 14 7 37 49 In Building N/A 3 5 12 4 24 50 SW 102 1 2 7 <MDA 10 51 SE 94 30 19 25 6 80 52 SE 105 8 1 11 <MDA 20

  • The control monitors are approximately 10 miles NW of MURR, and gross values are shown.
    • Badges that were missing during read period (likely lost due to weather), average of other three quarters were used.

VIII-5 TABLE 4 NUMBER OF FACILITY RADIATION AND CONTAMINATION SURVEYS

Surface Radiation Receipt of Month Radiation Air Samples** Radioactive Contamination* Work Permits Materials

January 127 127 50 22 7 February 93 93 47 22 15 March 144 144 47 16 11 April 150 150 34 17 13 May 131 131 44 14 12 June 99 99 47 21 12 July 98 98 56 24 12 August 122 122 39 27 18 September 112 112 53 26 9 October 141 141 41 15 16 November 99 99 40 24 11 December 92 92 36 20 7

TOTAL 1,408 1,408 534 248 143

  • 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 2023, MURR shipped 2,109 cubic feet of low-level radioactive waste containing 8,572 mCi of activity.

VIII-6 SECTION IX

SUMMARY

OF RADIATION EXPOSURE TO FACILITY STAFF, EXPERIMENTERS, AND VISITORS

January 1, 2023 through December 31, 2023

Total Personnel Dose (mrem) by Dosimetry Group

BCS DO FOE HP IRR NA NS NSP OPS PRD QA RES RP SH TEE Total January 0070334208471471,0322461427107112,279 February001193451271015768023241789674902,148 March 05574322298012893319238524106282,473 April1415729312710581,111120100187101,962 May04442281733110996112088141103131,862 June13727282126811,1031761151367541,956 July102441113076801,04424213122843162,165 August1311024761312117651,18330867545802,451 September409941118931321191,468340164641559193,014 October0137416188625721,1842561232326552,412 November4042191250107485657812501,248 December 04382971430621,20113610110253502,070 Total for Year37 19 658 4,1341,852103 116 937 12,7702,5161,651338 127 716 66 26,040 Monthly Average3 2 55 345 154 9 10 78 1,064210 138 28 11 60 6 2,170 Highest WB 19 8 84 633 551 18 63 149 674 179 330 106 42 142 13 (annual)

High Extremity175NM 682 846 859 1,097 135 2,939884 6,5694,567235 378 246 128 (annual)

BCS-Business & Central ServicesHP-Health PhysicsNSP-NorthStar PartnersRES-Research DO-Director's Office IRR-Irradiations OPS-Operations RP-Radiopharmaceutical FOE-Facilities Operations & EngineeringNA-Neutron ActivationPRD-ProductionSH-Shipping NS-Neutron ScatteringQA-Quality AssuranceTEE-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 Landauer (except self-reading dosimetry).

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