ML23089A071

North Carolina State Univ. - Annual Report for 2022

ML23089A071
Person / Time
Site:	North Carolina State University
Issue date:	03/30/2023
From:	Hawari A North Carolina State University
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML23089A071 (1)

Text

Nuclear Reactor Program Campus Box 7909 NC STATE Department of Nuclear Engineering 2500 Stinson Drive Raleigh, NC 27695-7909 UNIVERSITY nrp.ne.ncsu.edu 919.515.7294 (voice) 919.513.1276 (fax) 30 March 2023 Document Control Desk US Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852 Re: Annual Report for 2022 License No. R-120 Docket No. 50-297 In accordance with Technical Specification 6.7.4, the annual operating report for the North Carolina State PULSTAR Reactor facility is attached.

If you have any questions regarding this correspondence or require additiona l information, please contact Colby Fleming, Manager of Engineering and Operations at 919-515-3347, or via email at ncsorrel@ncsu.edu.

I declare under penalty of perjury that the forgoing is true and correct. Executed on 30 March 2023.

Director, Nuclear Reactor Program North Carolina State University

Enclosures:

Annual Operating Report for 2022 Attachment A: PULSTAR Reactor Environmental Radiation Surveillance Report 2022

Annual Operating Report for 2022 NORTH CAROLINA STATE UNIVERSITY DEPARTMENT OF NUCLEAR ENGINEERING PULSTAR REACTOR ANNUAL REPORT DOCKET NUMBER 50-297 For the Period: 01 January 2022 - 31 December 2022 The following annual report for 2022 is submitted in accordance with Section 6.7.4 of the North Carolina State University PULSTAR Reactor Technical Specifications:

6.7.4.a Brief Summary:

Reactor operations have been routine during this reporting period.

i Operating experience including a summary of experiments performed.

The reactor facility had a total of 2,106 h utilization hours in 2022. The utilization hours exceeded critical hours (1,567 h) since there was typically more than one user of the reactor facility at a given time. The following is a brief summary of the types of experiments performed, including for teaching laboratories, courses, research and service:

• 1/M Approach to criticality

• Control rod worth measurements

• Reactivity parameter measurements

• Core thermal power and coolant temperature measurements

• Axial power and peaking factor measurements (flux mapping)

• Reactor power determination using photodiode arrays

• Positron annihilation spectroscopy measurements

• Neutron diffraction measurements

• Neutron transmission measurements

• Neutron flux measurements

• Neutron detector testing and certification

• Neutron radiographic imaging

• Isotope production

• Accelerated lifetime testing for nuclear detectors

• Material irradiation for detector design

• Neutron activation analysis measurements

• Electronic component irradiation testing

• Ultracold neutron experimental testing 1

ii Changes in Performance Characteristics Related to Reactor Safety:

None iii Results of Surveillance, Tests, and Inspections:

The reactor surveillance program has monitored the following trend in reactor systems performance during this reporting period:

An unaccounted loss of primary water that began in 2015 continued through 2022. Efforts toward final repair the lower leak rate began in 2022 with Framatome contracted and beginning the initial design work. The concentration of radionuclides detected in the reactor coolant met regulatory limits for release to unrestricted areas (10 CFR 20 Appendix B Table 2).

The failure of a non-safety related reactor monitoring system (N-16 Channel) resulted in a TS violation which was reported to the NRC. This channel was repaired, and the reactor was returned to normal operations. After discussions with the NRC, efforts are underway to remove this historical caveat from the TS since the channel is not safety related and only provides secondary information regarding reactor power.

No other significant or unexpected trends in reactor systems performance have been identified during this reporting period.

The Reactor Safety and Audit Committee (RSAC) performed its annual audit for the facility and determined that all phases of operation and supporting documents were in compliance.

6.7.4.b Energy Output and Critical Hours:

Total Energy Output in 2022: 56.7 Megawattdays Critical hours in 2022: 1567.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> Cumulative Total Energy Output Since Initial Criticality: 2196.6 Megawattdays 6.7.4.c Number of Emergency and Unscheduled Shutdowns:

Emergency Shutdowns - None Unscheduled Shutdowns - Two 17-Feb-2022 Shutdown due to immediate operator action to deviation between the N-16 Power Monitoring Channel Simpson % Power meter and reactor power as indicated by the Linear, Safety, and Log-N Channels. The reactor was operating at 950 kW when the operator observed a power indication of 20% on the N-16 Channel. No SCRAM occurred as the N-16 Channel is not part of the reactor safety system. Further, the Linear, Safety, and Log-N Channels were all stable at a nominal power of 950kW in the period leading up to the shutdown.

Following shutdown, maintenance item #878 was opened and troubleshooting of the N-16 Channel components began. All portions of the N-16 Power Monitoring channel were tested and repaired or replaced as necessary. Upon completion of the repair, addressing the corrective action items, full calibration of the channel, and authorization for restart, the reactor was returned to normal operation.

As required by TS, a report was issued to the NRC on 02 March 2022 (Report for Event Number 55747 Technical Specification Violation ML22061A034).

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7-Oct-2022 Shutdown due to immediate operator action in response to magnet current failure for Safety 2 rod while the reactor was subcritical as a part of control rod worth measurements. Upon current failure, the Safety 2 rod immediately dropped into the core, performing its intended function. The reactor was shutdown by the operator inserting the remaining rods. Following the reactor shutdown, maintenance item #882 was opened. It was found through the maintenance repair that the loss of magnet current was due to a dislodged wire which was repaired. Upon completion of the repair, successful completion of a startup checklist, and authorization for restart, the reactor was returned to normal operations.

6.7.4.d Corrective and Preventative Maintenance:

Preventative maintenance, tests and calibrations are scheduled, performed and tracked utilizing the PULSTAR Surveillance File System. Each major component of the Reactor Safety System defined in Section 3.3, and all surveillance required by Section 4 of the Technical Specifications are monitored by this file system to ensure that maintenance and calibrations are performed in a timely manner. All historical data relating to those components, in addition to many other sub-systems, are maintained in these files. Any reactor equipment or components requiring corrective or preventative maintenance are tracked in the Maintenance Log (ML) file.

Maintenance Log items tracked during 2022 are listed below.

ML#866 PS-5-09-1A - West Wall (MER) Oxygen Monitor - West Wall O2 Monitor was placed out of service due to the supply voltage being out of range (F16(220) code). The East Wall O2 Monitor was still operating and indicated 20.9%. The O2 Monitors are used with particular experiments which were not operating and are not required for reactor operation. The West and East Wall O2 Monitors were replaced with new equipment and calibrated.

ML#875 PS-3-03 Primary Resin Channel - The resistivity in the primary system had been trending lower than 1Mcm but greater than 500kcm, indicating that the primary demineralizer resin needed to be replaced. The resin and the pre/post filters in the primary demineralizer loop were replaced.

ML#876 N/A - Neutron Flux Monitoring System (SN002) - Commissioning of the Neutron Flux Monitoring System (NFMS) is in progress. The Source Range Channel of the NFMS is completed. The Wide Range and Power Range are still being tested. Calibration was performed on NFMS (SN002) following voltage adjustments that were recommended by Thermofisher. Calibration was completed on 04 January 2022. Source Rage completed satisfactory. The Wide Range and Power Range are not currently used for operation. The Wide Range and Power Range still operate, but annunciations and trips are received from the LogN, Linear, and Safety Channels.

ML#877 PS-6-12 Stack Sample Pump (Stack Flow Fault Annunciator) - During the S/U checklist, the stack sample pump flow fault light and stack flow annunciator would not clear when the stack sample pump was operating and the actual flow was 2.82 cfm on the Flow Meter and Radiation Monitoring Recorder. The stack sample pump flow fault annunciator was repaired and the operates/energizes at 2.0 cfm.

ML#878 PS-1-08-4A - N-16 Channel - While the reactor was operating at a nominal power of 950 kW, the N-16 Channel (Simpson) % Power Meter indication decreased to 20%. All other power channels indicated steady at 950 kW. The reactor was shutdown in accordance with the immediate actions per abnormal channel behavior. All components of the N-16 Power Monitoring Channel were evaluated, repaired or replaced as necessary, and were operable per TS requirements. The Keithley electrometer was found to need repair, but all other components were also inspected and updated made as necessary. To assure operability following evaluation and servicing by and instrumentation support vendor, N-16 Power Monitoring Channel surveillance testing was completed and channel response with no deficiencies was observed for five days of reactor operation at a power level of less than 500 kW. The N-16 Power Monitoring Channel electrometer 3

output was connected to a digital data recorder and is recorded along with the other power monitoring channels allowing for review and comparison.

ML#879 PS-1-03-4A, PS-1-03 Linear Monitor - On Monday, 11 July 2022, the Linear Monitor Over-Power SCRAM alarm was sounding when the Control Room was unlocked. The Linear Monitor front panel HV and Compensating voltage were indicating a negative voltage and fluctuating. The NON-OP light was lit. The issue was isolated to a failed capacitor which was replaced. The channel was recalibrated, and the channel was found to operate satisfactorily.

ML#880 PS-5-06 D/P Gauge Bay to Corridor - During the startup checklist, the Bay to Corridor D/P gauge was reading 0.0 of water while testing the confinement/evacuation system (section H). Bay to Corridor D/P is not required by TS but was repaired before resuming with the checklist. The Bay to Corridor gauge was tested and verified to be operational. The supply airline was found to be faulty and was replaced. The Confinement System was tested and the D/P gauge in Confinement Mode of operation was found to be satisfactory after repair of the airline.

ML#881 PS-3-03 Primary Resin - Primary resin resistivity dropped below 1Mcm but greater than 500kcm, indicating that the primary demineralizer resin needed to be replaced. The resin and the pre/post filters in the primary demineralizer loop were replaced.

ML#882 PS-1-09-1A - SCRAM Logic Unit - While the reactor operator was adjusting Safety 2 magnet current from 60 mA to 45 mA, magnet current dropped from 60 mA to 0mA instantaneously and Safety 2 control rod dropped in the core. The reactor was not critical during the adjustment. The DRSO and MEO were notified and the RO shutdown and secured the reactor for troubleshooting and repair. The failure was found to be due to a broken wire on the magnet current adjustment resistor. The was re-attached to the resistor. Proper operation of the SLU was verified prior to startup. Startup checklist was performed prior to startup.

6.7.4.e Changes in Facility, Procedures, Tests, and Experiments:

Design changes to the facility, procedure changes, changes in tests and experiments, and other changes are tracked utilizing a Control Number (CN) indexing system. Changes tracked during 2022 are listed below.

Facility Changes Design changes to the reactor facility are reviewed to determine whether or not a 10 CFR Part 50.59 evaluation is required. Evaluation was performed for the design change. Based on the screening reviews performed, none of the changes listed below required a full 10 CFR 50.59 evaluation.

CN#873 Beam Port Modification for UCN Facility - Modification of the beam port is made for the experiment dimensions following repair of the reactor liner. Materials and operations remain the same.

Test and Experiments Tests and experiments are reviewed to determine whether or not a 10 CFR Part 50.59 evaluation is required.

No new test or experiment reviews were performed during this period.

Document Changes Procedure changes and minor changes are reviewed to determine whether or not a 10 CFR Part 50.59 evaluation is required. Based on the screening reviews performed, none of the changes listed below required 4

a full 10 CFR 50.59 evaluation. No changes to TS, license amendments, or NRC approvals were determined to be required. Procedure changes are tracked by Control Number (CN) as listed below.

CN#871 Emergency Procedure 1: Emergency Plan Activation and Response - This procedure change updated the name of Campus Police to NCSU Police, updated formatting, added WakeMed as off-site support organization, added Gardner Arboretum to describe the North BEL entrance, added information on use of fire alarm for evacuation purposes, and reworded statement on Raleigh HAZMAT team capabilities.

CN#872 Emergency Procedure 6: Emergency Preparedness; Training, Drills, and Inventory - This procedure change adds time frequency for training, simplifies wording for providing training, added information for training of Rex and WakeMed personnel, and reworded and added checks for emergency radio, call out list, BEL alarm, and emergency forms and logs.

CN#874 UltraCold Neutron Beamport Parts Installation and Removal - This procedure provides directions on installation and removal of the UCN beamport noseport extension, noseport, and shield box.

CN#875 UltraCold Neutron Beamport Parts Installation and Removal - This procedure change provides the opportunity to test and install the noseport extension (NPE) independently without the full noseport (NP) or unloading the reactor core.

CN#876 OP-101 Reactor Startup and Shutdown - New oxygen monitors were installed to replace the broken ones in the MER area near the UCN experimental system. These new monitors have a different acceptable tolerance, and the procedure is updated to reflect the range given in the oxygen monitor manual.

CN#877 Emergency Procedure 1: Emergency Plan Activation and Response - Attachment 8 Call Out List updated with new personnel names and phone numbers.

Other Changes CN#870 Emergency Plan - Emergency plan was updated to change Campus Police to NCSU Police as well as updated formatting and pagination. A secondary means of providing a building alarm was added by allowing for use of the fire alarm. WakeMed Hospital was added as a second medical provided for injured personnel and medical services. Additional quarterly testing of communications equipment was added, and Daniels Hall was renamed to 111 Lampe Drive. These changes were reviewed, and it was concluded that the effectiveness would not decrease. The changes were approved by the NCSU Reactor Safety and Audit Committee and Radiation Safety Committee prior to implementation. The changes do not decrease effectiveness of the emergency plan and are being made without prior NRC notification as allowed under 10 CFR 50.54. NRC notification of the Emergency Plan was sent on 12 July 2022 ML22193A202.

License Renewal Documentation:

In response to the request for additional information (RAI) regarding accident analysis for the license renewal, Response to Request for Additional Information RE: License Renewal Application for Facility Operating License No. R-120 for the North Carolina State University PULSTAR Research Reactor (EPID No. L-2017-RNW-0026);

dated August 23, 2021 ML22033A245, was sent to the NRC on 2 February 2022.

A License Amendment Request (LAR) for Fueled Experiments, ML22108A168 was sent to the NRC on 18 April 2022 in order to request the fueled experiment analysis be considered separately from the license renewal application.

In response to the NRC Renewal Audit Meeting in May 2022, Supplemental Information for Cladding Fuel Accident - Updated FSAR Section 13 for License Renewal Application for Facility Operating License R-120 for the North Carolina State University PULSTAR Research Rector (EPID No. L-2017-RNW-0026); dated 07 June 2022, was submitted on 08 June 2022 ML22159A237. This document updates the previous submission from 03 June 2022 ML22154A530.

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In response to the request for supplemental information for the acceptance of the license amendment request (LAR) for fueled experiments at the PULSTAR reactor, Supplemental Information Needed for Acceptance of the Application for a License Amendment Regarding Fueled Experiments for the PULSTAR Research Reactor (EPID L-2022-NFA-0004); dated 11 July 2022, was submitted on 12 July 2022 ML22193A167.

6.7.4.f Radioactive Effluent:

Liquid Waste (summarized by quarters)

i. Radioactivity Released During the Reporting Period:

Releases to the sanitary sewer are given below:

Period (1) (2) (3) (4)1 (5)

Total Number of Total Diluent Tritium 2022 Volume Batches Ci Liters Ci Liters 01 JAN - 31 MAR 2 72 6,624 11,122 70 01 APR - 30 JUN 3 198 10,121 2,703 197 01 JUL - 30 SEP 7 398 23,266 608 397 01 OCT - 31 DEC 3 188 9,992 0 187 2022 851 Ci of tritium was released during this year.

2022 856 Ci of total activity was released during this year.

1 Based on gross beta activity only. Tritium did not require further dilution.

ii. Identification of Fission and Activation Products:

The gross beta-gamma activity of the batches in (i) above were less than 210-5 Ci/ml. Isotopic analyses of these batches indicated low levels of typical corrosion and activation products. No fission products were detected.

iii. Disposition of Liquid Effluent not Releasable to Sanitary Sewer System:

All liquid effluent met the requirements of 10 CFR Part 20 for release to the sanitary sewer.

iv. Releases to Unrestricted Areas:

In 2022 an unaccounted loss of water from the reactor coolant system (RCS) occurred. The RCS water loss is measured every work day and occurred at variable rates over the year. RCS water was not observed in surface locations or storm sewer locations outside the reactor building. Therefore the unaccounted RCS water was assumed to be continuously released to grounds beneath the surface on the reactor site at the measured RCS loss rates over the year. Reactor coolant activity and volume assumed to be released to unrestricted areas are given below for 2022:

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Total Tritium Volume Period in 2022 Ci µCi Liters 01 JAN - 31 MAR 2,437 2,431 22,889 1 APR - 30 JUN 2,673 2,665 23,973 1 JUL - 30 SEP 2,971 2,963 25,254 1 OCT - 31 DEC 2,875 2,870 24,725 CALENDAR YEAR TOTAL 10,956 10,929 96,841 The concentration of radionuclides detected in the reactor coolant met regulatory limits for release to unrestricted areas (10 CFR 20 Appendix B Table 2). Detected radionuclides in reactor coolant were tritium and activation products. Fission products were not detected. No tritium or activation products were detected in environmental samples (refer to Section 6.7.4.i below).

Gaseous Waste (summarized monthly)

i. Radioactivity Discharged During the Reporting Period (in Curies) for:

(1) Gases:

Total Time Year Month Curies Hours JANUARY 744 0.692 FEBRUARY 672 0.872 MARCH 744 0.381 APRIL 720 0.376 MAY 744 0.545 JUNE 720 0.531 2022 JULY 744 0.399 AUGUST 744 0.510 SEPTEMBER 720 0.419 OCTOBER 744 0.298 NOVEMBER 720 0.597 DECEMBER 744 0.214 TOTAL 8760 5.834 (2) Particulates with a half-life of greater than eight days:

Particulate filters from the Stack Particulate Monitoring Channel were analyzed upon removal. There was no particulate activity with a half-life greater than 8 days detected.

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ii. Gases and Particulates Discharged During the Reporting Period:

(1) Gases:

Total activity of Argon-41 released was 5.833 Curies in 2022.

The yearly average concentration of Argon-41 released from the PULSTAR reactor facility exhaust stack in 2022 was 2.8310-8 Ci/ml. Dose calculations for the year were performed using methods given in the Final Safety Analysis Report and gave results less than the 10 CFR Part 20 constraint level of 10 mrem. These results are consistent with environmental monitoring data given in Attachment A.

(2) Particulates:

Refer to gaseous waste i.(2) above. No activation or fission products were detected.

Solid Waste from Reactor

i. Total Volume of Solid Waste Packaged Total volume of solid waste was 59 ft3.

ii. Total Activity Involved Total activity for solid waste was 3.83 mCi.

iii. Dates of shipments and disposal Transfer of solid radioactive waste to the university broad scope radioactive materials license was made in February, March, April, August, September, and November 2022. The University Environmental Health and Safety Center arranges disposal of hazardous wastes.

6.7.4.g Personnel Radiation Exposure Report:

Thirty individuals were monitored for external radiation dose during the reporting period. Internal dose monitoring was not required for any individual. Collective deep dose-equivalent was 2.727 person-rem.

Individual deep dose-equivalent ranged from 0.000 rem to 0.798 rem with an average of 0.091 rem. Two individuals were above 0.250 rem.

6.7.4.h Summary of Radiation and Contamination Surveys Within the Facility:

Radiation and contamination surveys performed within the facility indicated that:

• Radiation in the majority of areas was 5 mrem/h or less.

• Radiation in the remaining areas was higher due to reactor operations.

• Contamination in most areas was not detectable. When contamination was detected, the area or item was confined or decontaminated.

6.7.4.i Description of Environmental Surveys Outside of the Facility:

Refer to Attachment A for results of environmental sampling and analysis.

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Radiation surveys performed in unrestricted areas near the reactor facility indicated that:

• Radiation was at background levels for most areas (background is approximately 20 µrem/h).

• Contamination was not detectable.

• Net radiation readings ranged from 0 to 30 µrem/h while the reactor was operating at power.

Radiation was at background levels in all routinely occupied spaces.

• Water samples from Rocky Branch Creek and two on-site ground water monitoring wells were analyzed in 2022 for tritium, gross beta activity, and gamma radiation. All sample results were consistent with background radioactivity. Environmental monitoring of Rocky Branch Creek and groundwater is routinely performed in accordance with facility procedures.

Gross beta concentrations for all MW-1 and MW-2 samples were below the environmental gross beta activity limit of 5x10-8 µCi/ml.

Tritium concentration in MW-1 and MW-2 were below the minimum detectable activity (MDA). The MDA was approximately 3 percent of the environmental limit of 2x10-5 µCi/ml.

Gamma isotopic analysis for MW-1 and MW-2 samples were below 10 percent of the concentration given in 10 CFR Part 20 Appendix B Table 2 for individual radionuclides of concern from reactor operation. MW-1 samples were analyzed quarterly and MW-2 samples were analyzed monthly.

Analysis of gross alpha activity in samples from MW-1 and MW-2 was not necessary since gross alpha activity in reactor primary coolant samples taken monthly were below the detection limit of 2x10-10

µCi/ml. This detection limit is below the environmental limit of 1.5x10-8 Ci/ml. Procedures for MW-1 and MW-2 analysis do not require gross alpha monitoring if there is no fuel damage. No fuel damage has ever occurred at this facility.

Results for Rocky Branch Creek are given in Appendix A. No activation or fission products were detected.

2022 Results for MW-1 and MW-2 Samples:

Sample Gross Beta Gross Beta Tritium Tritium Sample Date uCi/ml MDA uCi/ml MDA uCi/ml uCi/ml MW1 1/18/22 MDA 1.27E-08 MDA 5.03E-07 MW1 4/20/22 8.23E-09 8.33E-09 MDA 4.50E-07 MW1 7/19/22 1.16E-08 7.92E-09 MDA 5.66E-07 MW1 10/19/22 1.38E-08 8.30E-09 MDA 5.96E-07 Note: Gross beta results above the MDA were due to naturally occurring radionuclides.

No activation or fission products were detected by gamma spectroscopy.

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Sample Gross Beta Gross Beta Tritium Tritium Sample Date uCi/ml MDA uCi/ml MDA uCi/ml uCi/ml MW2 1/18/22 MDA 5.64E-09 MDA 5.03E-07 MW2 2/21/22 1.27E-08 1.31E-08 MDA 4.46E-07 MW2 3/17/22 2.08E-08 5.65E-09 MDA 4.46E-07 MW2 4/20/22 MDA 8.33E-09 MDA 4.76E-07 MW2 5/18/22 1.16E-08 5.58E-09 MDA 6.06E-07 MW2 6/20/22 1.48E-08 5.54E-09 MDA 5.94E-07 MW2 7/18/22 1.54E-08 8.35E-09 MDA 5.66E-07 MW2 8/22/22 2.18E-08 1.02E-08 MDA 6.21E-07 MW2 9/26/22 1.11E-08 8.16E-09 MDA 6.25E-07 MW2 10/19/22 MDA 8.32E-09 MDA 5.96E-07 MW2 11/17/22 8.67E-09 7.99E-09 MDA 5.99E-07 MW2 12/22/22 1.60E-08 8.15E-09 MDA 5.99E-07 Note: Gross beta results above the MDA were due to naturally occurring radionuclides.

No activation or fission products were detected by gamma spectroscopy.

Maximum gamma isotopic MDA for specific radionuclides for MW-1 and MW-2:

Nuclide MDA (Ci/ml) 10 CFR PART 20 App. B (Ci/ml)

Cr-51 7.0E-7 5 E-4 Mn-54 8.5E-8 3 E-5 Co-58 8.5E-8 2 E-5 Fe-59 1.6E-7 1 E-5 Co-60 5.1E-8 3 E-6 Zn-65 1.5E-7 5 E-6 Mo-99 7.1E-8 2 E-5 Ag110m 8.6E-8 6 E-6 Sb-124 8.0E-8 7 E-6 I-131 8.7E-8 1 E-6 Cs-137 9.7E-8 1 E-6 La-140 7.4E-8 9 E-6 10

ATTACHMENT A:

PULSTAR Reactor Environmental Radiation Surveillance Report 2022

ATTACHMENT A PULSTAR REACTOR ENVIRONMENTAL RADIATION SURVEILLANCE REPORT FOR THE PERIOD JANUARY 1, 2022 - DECEMBER 31, 2022 NORTH CAROLINA STATE UNIVERSITY ENVIRONMENTAL HEALTH AND SAFETY CENTER RADIATION SAFETY by Alyson Prior, Environmental Health Physicist Scott Lassell, Radiation Safety Officer

TABLE OF CONTENTS PAGE NO.

1. INTRODUCTION 3 Table 1 Environmental Monitoring Programs for the PULSTAR Reactor 4

2. AIR MONITORING 5 Table 2.1 Location of Air Monitoring Stations 5 Table 2.2 Airborne Gross Beta Activities 6 Table 2.3 Airborne Gamma Activities (LLD Values) 6 Table 2.4 Regulatory Limits, Alert Levels and Background Levels 7 for Airborne Radioactivity

3. MILK Table 3.1 I-131 in Cows Milk 7

4. SURFACE WATER Table 4.1 Gross Alpha and Beta Activity in Surface Water 8 Table 4.2 LLD Values for Gamma Emitters in Surface Water 9 Table 4.3 Tritium Activity in Surface Water 9

5. VEGETATION Table 5.1 Gross Beta Activity in Campus Vegetation 10 Table 5.2 LLD Values for Gamma Emitters in Vegetation 10

6. OPTICALLY STIMULATED DOSIMETERS 11 Table 6.1 Environmental Dosimeter Doses 11

7. QUALITY CONTROL INTERCOMPARISON PROGRAM 12 Tables 7.1 & 7.2 13 -14

8. CONCLUSIONS 15 2

1. INTRODUCTION The Environmental Radiation Surveillance Program exists to provide routine measurements of the university environment surrounding the PULSTAR Reactor.

The specific objectives of this program include:

1) Providing information that assesses the adequacy of the protection of the university community and the public-at-large;

2) Meeting requirements of regulatory agencies;

3) Verifying radionuclide containment in the reactor facility;

4) Meeting legal liability obligations; and

5) Providing public assurance and acceptance.

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Table 1 Environmental Monitoring Programs for the PULSTAR Reactor at North Carolina State University Conducted Previous Current Basis For Sample Activity Measured By Frequency Frequency Measurement Stack 10 CFR 20 Gross Gamma N.E. Continuous Continuous Gases T.S. 6.7.4 Stack Gross Beta N.E. 10 CFR 20 Monthly Monthly Particles Gamma N.E. T.S. 6.7.4 10 CFR 20 Water from Gross Beta N.E. Prior to Prior to T.S. 6.7.4 Reactor Gamma N.E. Discharge Discharge City of Facility Tritium N.E. (~ Monthly) (~ Monthly) Raleigh Ordinance Air Particles at 4 Gross Beta RSD Weekly Quarterly 10 CFR 20 Campus Gamma RSD Weekly Quarterly 10 CFR 20 Stations*

Air Dose at 7 Campus OSD Dosimeter RSD Quarterly Quarterly 10 CFR 20 Stations +

Surface Water Gross Alpha/Beta RSD Quarterly Quarterly NCSU Rocky Gamma RSD Quarterly Quarterly NCSU Branch Tritium RSD --------------- Quarterly 10 CFR 20 Creek Vegetation Every Gross Beta RSD NCSU NCSU Semi-annually Other Gamma RSD NCSU Campus Year Milk Every I-131 RSD Monthly Other NCSU Local Dairy Year Abbreviations Used in Table:

N.E. = Nuclear Engineering/Reactor Facility; RSD = Radiation Safety Division.

• These 4 stations include:

Withers, Lampe, Polk and the Environmental Health & Safety Center (EHS).

+These 7 stations include: The PULSTAR Reactor, the 4 air sampling stations, North Hall and an Area 1 control station at the Environmental Health and Safety Center.

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2. AIR MONITORING Air monitoring is performed continuously for one week during each of four calendar quarters during the year at the locations given in Table 2.1.

The data in Table 2.2 represents gross beta activity levels measured during the year.

The highest gross beta activity observed was 24.2 fCi/cubic meter at the Lampe station during the week of 10/19/2022 to 10/25/2022. The annual campus average value was 16.2 fCi/cubic meter.

Table 2.3 lists LLD values for several gamma emitters which would be indicative of fission product activity. No gamma activity due to any of these radionuclides was detected.

Table 2.4 lists regulatory limits, alert levels, and average background levels for airborne radioactivity.

TABLE 2.1 LOCATION OF AIR MONITORING STATIONS SITE DIRECTION1 DISTANCE2 ELEVATION3 (meters) (meters)

LAMPE

• SOUTHEAST 90 -8 WITHERS NORTHEAST 82 -6 EHS CENTER WEST 1230 -3 NORTH HALL ** NORTHEAST 402 -4 POLK HALL WEST 100 -7 1

DIRECTION - DIRECTION FROM REACTOR STACK 2

DISTANCE - DISTANCE FROM REACTOR STACK 3

ELEVATION - ELEVATION RELATIVE TO THE TOP OF THE REACTOR STACK

• LAMPE was formerly named DANIELS

• • Only dosimeter monitoring 5

TABLE 2.2 Airborne Gross Beta Activity (fCi/cubic meter +/- 2)

PERIOD Polk Lampe Withers EH&S 2022 Not Sampled 1 No Data No Data No Data No Data 04/13 - 04/27 15.7 +/- 1.8 6.7 +/- 1.4 17.0 +/- 1.9 10.6 +/- 1.6 7/22 - 8/10 2 17.1 +/- 1.9 14.8 +/- 1.8 23.1 +/- 2.2 17.7 +/- 1.9 10/20 - 10/31 21.9 +/- 2.1 24.2 +/- 2.2 20.0 +/- 2.0 5.7 +/- 1.3 1

Due to staff turnover, air sample data was not taken during the first quarter. Air effluent samples are analyzed by the reactor staff for gross beta activity weekly and gamma activity monthly. Reactor effluent data for the first quarter (Jan, Feb, Mar) gross beta activity concentrations were below 4.2x10-13 Ci/ml.

Gamma activity measurements of reactor effluent did not detect any activation or fission product activity.

All gamma activity detected in the reactor effluent was from naturally occurring radioactive materials.

2 Withers was sampled during the time frame 8/20 - 8/30/2022 due to problems with the air sampler units overheating.

TABLE 2.3 Airborne Gamma Activity LLD Values (fCi/cubic meter)

PERIOD Co-57 Co-60 Nb-95 Zr-95 Ru-103 Ru-106 Cs-137 Ce-141 Ce-144 2022 Not Sampled No Data No Data No Data No Data No Data No Data No Data No Data No Data 04/13 - 04/27 0.13 0.30 0.41 0.36 0.17 2.08 0.21 0.41 1.53 7/22 - 8/10 0.22 0.26 0.29 0.50 0.17 2.05 0.29 0.46 0.17 10/20 - 10/31 0.21 0.35 0.20 0.37 0.33 1.74 0.33 0.37 0.77 6

TABLE 2.4 REGULATORY LIMITS, ALERT LEVELS, AND BACKGROUND LEVELS FOR AIRBORNE RADIOACTIVITY (fCi M -3).

REGULATORY INVESTIGATION *AVERAGE N.C.

NUCLIDE LIMIT LEVEL BACKGROUND LEVEL GROSS BETA 1000 500 20 Cs-137 2 X 105 100 2 Ce-134 2 X 105 100 0 Nb-95 2 X 106 100 0 Zr-95 400 100 0

• This data represents an average value measured in North Carolina at various locations.

Excerpted from 2009 Environmental Surveillance Report produced by the NC Department of Health and Human Services Radiation Protection Section.

3. MILK Milk samples are collected every other year from the Campus Creamery and the Lake Wheeler Road Dairy as processed milk and raw milk and analyzed for I-131. No samples were collected this year due to being sampled in 2021.

TABLE 3.1 I-131 IN COWS MILK (pCi Liter -1 2 ) LLD ~ 2 pCi Liter -1 DATE Campus Creamery Lake Wheeler NA No Data No Data 7

4. SURFACE WATER Table 4.1 gives the gross alpha and beta activities measured for water samples taken from Rocky Branch creek at points where it enters (ON), behind Carmichael Gymnasium (GYM) and exits (OFF) the campus. The LLD value for gross alpha and beta activities is ~ 1.5 and 0.9 pCi Liter-1 respectively. The gross alpha activity investigation Level is 5 pCi Liter-1 and the Regulatory Limit is 15 pCi Liter-1. For gross beta activity the Investigation Level is 12.5 pCi Liter-1 and the Regulatory Limit is 50 pCi Liter-1.

Gamma analysis of all samples was also performed. All of the results obtained are consistent with the presence of naturally-occurring radionuclides and none of the gamma emitters listed in Table 4.2 were measurable above detection limits.

Tritium activity analyzed does not exceed the regulatory limit of 2 x 104 pCi Liter-1. Tritium activity was not detected above the LLD value of ~ 500 pCi Liter-1.

TABLE 4.1 GROSS ALPHA AND BETA ACTIVITY IN SURFACE WATER (pCi Liter 1 2)

LLD ~ 1.5 pCi Liter-1 LLD ~ 0.9 pCi Liter 1 GROSS ALPHA GROSS BETA 2022 QUARTER LOCATION pCi Liter 1 pCi Liter 1 FIRST QUARTER ON No Data* No Data*

OFF No Data* No Data*

GYM No Data* No Data*

SECOND QUARTER ON 1.8 1.2 3.5 0.7 OFF 1.8 1.1 3.8 0.8 GYM 2.7 1.3 2.1 0.7 THIRD QUARTER ON 1.4 0.9 4.7 + 0.7 OFF 3.2 1.1 4.3 + 0.6 GYM 1.2 1.1 4.2 + 0.7 FOURTH QUARTER ON 0.8 0.8 3.6 + 0.7 OFF 0.4 0.6 3.5 + 0.7 GYM 0.1 0.5 3.2 + 0.7

• Due to staff turnover, the first quarter samples were analyzed and tested, but sample volumes were below one liter. First quarter sample count rates were consistent with the 2nd, 3rd, and 4th quarter values. Samples taken by the PULSTAR reactor staff in the first quarter were analyzed for gross beta and tritium activity. Gross beta activity for a composite sample of the ON, OFF, and GYM locations from Rocky Branch Creek was not detected above the detection limit of 8.4 pCi Liter-1. Tritium activity for the ON, OFF, and GYM locations from Rocky Branch Creek were not detected above the detection limit of 500 pCi Liter-1. Gross alpha activity for samples from Rocky Branch Creek were not measured. The reactor pool water gross alpha activity for the Jan, Feb, and Mar monthly samples measured by the reactor staff were below 6.4x10-2 pCi Liter-1.

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TABLE 4.2 LLD VALUES FOR GAMMA EMITTERS IN SURFACE WATER

• NUCLIDE LLD (pCi Liter-1)

Co-60 1.22 Zn-65 1.49 Cs-137 1.17 Cs-134 1.13 Sr-85 1.16 Ru-103 0.90 Ru-106 7.53 Nb-95 0.95 Zr-95 1.19 TABLE 4.3 TRITIUM ACTIVITY IN SURFACE WATER (pCi Liter 1 2)

LLD ~ 500 pCi Liter-1 2022 QUARTER LOCATION TRITIUM CONCENTRATION pCi Liter 1 FIRST QUARTER ON No Data*

OFF No Data*

GYM No Data*

SECOND QUARTER ON 0 376 OFF -156 379 GYM -102 374 THIRD QUARTER ON 25 367 OFF 0 367 GYM 51 375 FOURTH QUARTER ON -606 430 OFF -688 415 GYM -831 423

• Due to staff turnover, first quarter surface water samples were not analyzed for gamma or tritium activity.

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5. VEGETATION The vegetation sampling is performed every other year and analyzed for gross beta activity as well as gamma activity. Table 5.1 gives gross beta activities for grass samples collected on the NCSU Campus. Table 5.2 lists LLD values for several gamma emitters. Due to being sampled in 2021, no samples were collected for 2022.

TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION *LLD ~ 0.5 pCi g-1 SAMPLE DATE SAMPLE LOCATION (pCi g-1 2)

NA NORTH CAMPUS No Data NA SOUTH CAMPUS No Data NA EAST CAMPUS No Data NA WEST CAMPUS No Data TABLE 5.2 LLD VALUES FOR GAMMA EMITTERS IN VEGETATION NUCLIDE LLD (pCi g-1)

Co-60 No Data Zn-65 No Data Cs-137 No Data Cs-134 No Data Sr-85 No Data Ru-103 No Data Nb-95 No Data Zr-95 No Data 10

6. OPTICALLY STIMULATED DOSIMETERS Dosimeter analysis is contracted to Landauer, Inc. for determination of ambient radiation exposures.

Exposures are integrated over a three-month period at each of the air monitor stations listed in Table 2.1 and at the PULSTAR Reactor facility. An Area 1 control dosimeter is located in the Environmental Health & Safety Center. Table 6.1 gives the dose equivalent data for these seven (7) locations.

The dose equivalents are reported as millirem per quarter year. Readings which fall below the dosimeters minimum measurable quantities (i.e., 1 millirem for gamma radiations and 10 millirem for beta radiation) are reported by the contract vendor with the designation M. The observed readings are typically within the expected range for natural background radiation levels.

TABLE 6.1 ENVIRONMENTAL DOSIMETER DOSES - Millirem per Quarter Period Control Control Polk Withers Lampe EHS North PULSTAR (2022) Area 1 01/01-03/31 36 1 M,M M,M M,M M M 22 04/01-06/30 35 M M,M M1 M1 M M 18 07/01-09/30 36 M M,M M,M M1 2 M 20 10/01-12/31 35 M M,M M,M M,M M M 23 Note: Landauer Control dose is measured by the vendors Control Dosimeter which is included with each shipment to monitor radiation exposure received during transit. It is maintained in a radiation free area during the calendar quarter period. Control Area 1 dose is measured by a dosimeter maintained in an office location away from radiation sources.

1 Only one dosimeter was utilized for these measurements due to staff turnover.

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7. QUALITY CONTROL INTERCOMPARISON PROGRAM The Environmental Radiation Surveillance Laboratory (ERSL) in the Radiation Safety Division has analyzed samples provided by the U.S. DOE Mixed-Analyte Performance Evaluation Program (MAPEP Test Session 45) Radiological and Environmental Sciences Laboratory (RESL) during this reporting period. The objective of this program is to provide laboratories performing environmental radiation measurements with unknowns to test their analytical techniques.

The MAPEP value listed in the Tables 7.1 and 7.2 to which the ERSL results are compared is the mean of replicate determinations for each nuclide. The MAPEP uncertainty is the standard error of the mean.

For each reported radiological analyte, the laboratory result and the reference value may be used to calculate a relative bias:

(100)(Laboratory Re sult RESL Re ferenceValue)

%Bias =

RESL Re ferenceValue The relative bias will place the laboratory result in one of three categories:

Acceptable Bias 20%

Acceptable with Warning... 20% < Bias 30%

Not Acceptable. Bias > 30%

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TABLE 7.1 MULTINUCLIDE WATER SAMPLE - INTERCOMPARISON STUDY 16 November 2022 The sample consists of a spiked aliquot of acidified water (~5 % HNO3). The reported values and the known values are given in Bq/Liter.

NCSU - Environmental Laboratory Results (Water Sample) (Bq/Liter)

Reported Value Reported Error Radionuclide MAPEP Value Acceptance Range (NCSU) (NCSU)

Co-57 1 ----- ----- 30.0 21.0 - 39.0 Co-60 14.8 0.5 17.0 11.9 - 22.1 Cs-137 15.6 0.7 16.8 11.8 - 21.8 Cs-134 12.1 0.5 17.1 12.0 - 22.2 Mn-54 ----- ----- ----- False Positive Zn-65 8.4 0.8 11.3 7.9 - 14.7 Gross Alpha 0.35 0.14 0.87 0.26 - 1.48 Gross Beta 3.40 0.11 5.20 2.60 - 7.80 Note: The entry "-----" indicates no analyte was present 1

The NCSU reported value was noted to not be within the acceptance range. Evaluation and implementation of corrective actions are in process.

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TABLE 7.2 MULTINUCLIDE AIR FILTER - INTERCOMPARISON STUDY 16 November 2022 The sample consists of a 50 mm diameter glass fiber filter which has been spiked with a solution and dried. The reported values and the known values are given in Bq/filter.

NCSU - Environmental Laboratory Results (Air Filter) (Bq/filter)

Reported Value Reported Error Radionuclide MAPEP Value Acceptance Range (NCSU) (NCSU)

Co-57 1 2.0 0.10 3.3 2.3 - 4.3 Co-60 1.9 0.04 2.0 1.4 - 2.6 Cs-137 1.4 0.05 1.5 1.1 - 2.0 Cs-134 ----- ----- ----- False Positive Mn-54 1.5 0.05 1.9 1.3 - 2.4 Zn-65 1.3 0.10 1.6 1.1 - 2.1 Gross Beta 1.29 0.09 1.31 0.66 - 1.97 Note: The entry "-----" indicates no analyte was present 1

The NCSU reported value was noted to be outside the acceptance range. Evaluation and implementation of corrective actions are in process.

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8. CONCLUSIONS The data obtained during this period do not show any detectable activation or fission product activity. The observed environmental radioactivity is due primarily to radon progeny, primordial radionuclides (e.g. K-40) and those radionuclides which originate in the upper atmosphere as the result of cosmic ray interactions.

These facts justify the conclusion that the PULSTAR Reactor facility continues to operate safely and does not release by-product activation or fission product materials into the environment.

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