ML25240B502
| ML25240B502 | |
| Person / Time | |
|---|---|
| Site: | Washington State University |
| Issue date: | 08/28/2025 |
| From: | Hines C Washington State Univ |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| Download: ML25240B502 (1) | |
Text
Nuclear Science Center PO Box 641300, Pullman, WA 99164-1300 l 509-335-8641 l nsc.wsu.edu l or.nsc@wsu.edu
August 28, 2025 Document Control Desk U.S. Nuclear Regulatory Commission Washington DC, 20555
Reference:
Washington State University Modified TRIGA Reactor License No. R-76; Docket No.50-027
Subject:
2025 Annual Report for the WSU Nuclear Science Center The annual report for the WSU reactor facility is hereby submitted. The report covers the operating period from July 1, 2024 through June 30, 2025.
Respectfully submitted, C. Corey Hines, Director Enclosure cc:
Clark J. Filip, Reactor Manager, Nuclear Science Center WA Department of Health, Office of Radiation Protection
ANNUAL OPERATIONS REPORT 2025 WASHINGTON STATE UNIVERSITY TRIGA REACTOR FACILITY LICENSE R-76 FOR THE REPORTING PERIOD JULY 1, 2024 TO JUNE 30, 2025 NUCLEAR SCIENCE CENTER l Washington State University, Pullman, WA
2025 Annual Report Washington State University Nuclear Science Center TABLE OF CONTENTS
- 1.
NARRATIVE
SUMMARY
OF OPERATION FOR FISCAL YEAR 2025................ 2
- 2.
ENERGY AND CUMULATIVE OUTPUT............................................................... 2
- 3.
EMERGENCY SHUTDOWNS AND INADVERTENT SCRAMS........................... 3
- 4.
MAJOR MAINTENANCE....................................................................................... 3
- 5.
CHANGES, TESTS, AND EXPERIMENTS PERFORMED UNDER 10 CFR 50.59 CRITERIA.............................................................................................................. 4
- 6.
RADIOACTIVE EFFLUENT DISCHARGES.......................................................... 5
- 7.
PERSONNEL AND VISITOR RADIATION DOSES.............................................. 6
- 8.
REACTOR FACILITY RADIATION AND CONTAMINATION LEVELS................. 8
- 9.
ENVIRONMENTAL MONITORING PROGRAM................................................. 11
2025 Annual Report Washington State University Nuclear Science Center Page 2 of 14
- 1.
Narrative Summary of Operation for Fiscal Year 2025 A.
Operating Experience Core 35A has accumulated 17,580 MWH from beginning of life (BOL) through June 30, 2025. During the reporting period of July 1, 2024 to June 30, 2025, a total of 1,424 samples were irradiated, for 11,978 user-hours. Additionally, 6 pulses greater than $1.00 of reactivity addition were performed during the reporting period. The quarterly operations summaries are shown in Table I.
B.
Changes in Facility Design, Performance Characteristics, and Operating Procedures Related to Reactor Safety:
The Standard Operating Procedures Revision 0.8 were approved by the Reactor Safeguards Committee on 10/16/2024.
C.
Results of Surveillance Tests and Requirements:
Surveillance tests and requirements were performed and completed within the prescribed time period.
- 2.
Energy and Cumulative Output The quarterly operations summaries are given in Table I. The cumulative energy output since the 1967 TRIGA fuel core was put into service is 1,962 megawatt days (MWD). The mixed Standard Fuel and 30/20 LEU Fuel Core 35A installed in 2008 has accumulated 732 MWD.
Table I.
Fiscal Year 2025 Summary of Reactor Operation1 Q3 2024 Q4 2024 Q1 2025 Q2 2025 Totals Hours of Operation 315 357 203 289 1,164 Megawatt Hours 274 344 200 288 1,106 Sample Irradiations 92 69 53 102 316 Samples 527 253 270 374 1,424 External Irradiations 20 19 24 23 86 Pulses > $1.00 0
3 0
3 6
User Hours 2,523 1,671 4,142 3,643 11,978 1 Number of samples and sample irradiations do not include external client irradiations. User hours denotes the total user hours, including external client irradiations.
2025 Annual Report Washington State University Nuclear Science Center Page 3 of 14
- 3.
Emergency Shutdowns and Inadvertent Scrams During the reporting period, there were no emergency shutdowns.
The dates and causes of the ten inadvertent scrams are listed in Table II. No scrams were due to exceeding the limiting safety system setting or safety limit.
Table II.
Inadvertent Scrams Date Description 11/8/2024 During a startup as the operator was raising Control Element 2 to ~6.5", Control Element 2 disengaged and the transient rod scrammed. Suspected cause would be noise or a blip in the power grid.
12/18/2024 During steady-state operations, the reactor scrammed. Suspected cause was a brief loss of power.
9/19/2023 Control Element 1 disengaged during operation when knocked by an operator inserting a sample for irradiation.
2/10/2025 During steady-state operations, air SCRAM occurred. The cause was the closure of the short period SCRAM switch cover, causing a low pulse air pressure alarm and blade disengaged alarm for Control Element 1.
4/15/2025 During steady-state operations, fire alarm was actuated reactor operator manual scrammed.
4/17/2025 During steady-state operations, fire alarm was actuated reactor operator manual scrammed.
4/18/2025 During steady state operations operator was removing a short term sample from D8 and dropped the grabbers into the pool and yelled scram. Reactor Operator immediately Manual Scrammed the reactor.
4/29/2025 During steady-state operations, loss of power caused blade 1 to disengage and an air SCRAM to occur.
5/8/2025 During steady state operation student trainee was instructed to raise a control rod, moved mode selector switch instead of control element selector switch causing an air scram and the rods to unexpectedly drop.
5/29/2025 During steady state operation, contractors in the machine room turned off the air compressor.
The operator got a low pulse air alarm sometime after the air was shutoff. The operator air scrammed and ran down.
- 4.
Major Maintenance Although they are not part of routine preventative maintenance, the below listed items were performed.
7/1/2024: A special bracket was made to securely hold the pool water temperature probe and water-tight tube. The bracket was verified to not interfere with probe accuracy with an independent thermometer suspended at the same location.
2025 Annual Report Washington State University Nuclear Science Center Page 4 of 14 9/18/2024: When performing the monthly Channel Test of the EGM, the display for the TC 555P counter did not display. The counter was replaced with an Ortec 871 which correctly displayed and the Calibration and Channel Check were reperformed.
2/10/2025: The cooling tower basin level sensor failed and was under warranty and replaced by contractor with a sensor capable of operating in conditions down to -20 F.
2/19/2025: Battery A in the ARIES system was found to not hold a charge. It was replaced with an equivalent deep cycle marine battery.
2/26/2025: Control Element 2 repeatedly dropped during checkout scram tests while a low current was applied to the magnet. The limit switch for the magnet was manually adjusted until the current reached the appropriate level.
5/21/2025: The lower button on the console did not engage when pressed, however control rods were still able to be dropped via normal rundown procedures. The console relay responsible for the button was replaced with an identical part.
5/23/2025: Following a building electrical shutdown for planned maintenance, the buildings water booster pump system did not restart properly. This led to a delivery failure of supply water to the air-gapped makeup water system for the reactor pool.
This allowed for air injection into the IX system which required priming and bleeding once water pressure was restored to the building. Procedures to properly restart the building booster pump system were developed by WSU Facilities for implementation after electrical outages.
5/27/2025: The EGM pump was observed to be making an unusual noise. It was replaced with an identical model.
- 5.
Changes, Tests, and Experiments Performed Under 10 CFR 50.59 Criteria A total of six proposed changes to the facility was reviewed during the 2024-2025 year.
The proposals were screened and evaluated with the 10 CFR 50.59 requirements and found to screen out, thus allowing the change to be made. The following change was made to the facility under 50.59 criteria:
50.59-114-2024: An Omega digital paperless chart recorder replaced an analog paper chart recorder capable of performing the same function at higher resolution and allow for digital search and analysis of electronically recorded chart data.
50.59-115-2024: A Marley model NC8402PAN1 cooling tower was installed to replace the Chandler model RSD-250 cooling tower which had reached its end of life. The secondary pump was replaced. The air/dirt separator was removed and replaced with a Wye strainer. Both the tower fan and the secondary pump are controlled by separate variable frequency drives (VFD) allowing for dynamic response to cooling needs and energy savings. A new water treatment system, to include a blowdown system, was added to control the initial passivation of the interior surfaces as well as to continuously prevent scale, corrosion, and algal growth over the long term. Local readout pressure and temperature gauges were replaced with similar models.
2025 Annual Report Washington State University Nuclear Science Center Page 5 of 14 50.59-116-2024: A modification to Standard Operating Procedure 25, Core Changes and Fuel Movement (SOP 25, Rev. 0.8A) was made to accommodate the Purple Finch exercise comprised of Plutonium Verification Team (PVT) members from Sandia, Los Alamos, Savannah River, and Pacific Northwest National Laboratories.
The modifications allowed for the PVT to utilize an Advanced Experimental Fuel Counter (AEFC) to measure fuel clusters during the exercise.
50.59-118-2024: A new tool was designed for tightening the ion exchanger lid. The new tool is configured to allow for ergonomically safer use by operators and for the attachment of a torque wrench which allows for more consistent pressure across the lid minimizing the potential for leaks following maintenance related removal or manipulation.
50.59-117-2025: Long-term irradiation/experimental positions were added to core positions C9 and F9 with specially designed split grid plate adapter baskets that replace the single irradiation/experimental position baskets originally occupying C8 and F9. C9 and F9 were vacant positions had and not been utilized as irradiation/experimental positions to date.
50.59-119-2025: A Yokogawa digital paperless chart recorder replaced the Omega digital paperless chart recorder which had a failed backlight.
- 6.
Radioactive Effluent Discharges A.
Radioactive Liquid Effluent Releases The liquid effluent releases for the facility during the reporting period are provided in Table III.
Table III.
Monthly Liquid Effluent Releases Month Volume (gallons)
July 2024 0
August 0
September 0
October 0
November 0
December 0
January 2025 0
February 0
March 0
April 0
May 0
June 0
2025 Annual Report Washington State University Nuclear Science Center Page 6 of 14 No liquid effluents were released from the storage tank during the reporting period.
B.
Radioactive Gaseous Effluent Release During the reporting period, no emission of a measurable quantity of gaseous or particulate material with a half-life greater than eight days was detected. The measured argon-41 out of the common exhaust stack did not exceed 20% of the effluent release limit. A total of 1.94 Ci of argon-41 was released, with an average argon-41 concentration of 9.89 x 10-11 µCi/mL of air, after environmental dilution. The argon-41 release and the pool water analysis is used in the 2025 Annual Report for Radioactive Air Emission License (RAEL-004), stack number 7. Per COMPLY v1.7, the reactor facility (stack 7) complies at level 4 with an effective dose equivalent of 2.5 x 10-3 mrem/yr. The monthly releases from Ar-41 are summarized in Table IV.
Table IV.
Monthly Argon-41 Releases2 Month Quantity (Ci)
Conc. After Dilution (µCi/mL)
% of DAC Limit July 2024 3.1E-01 1.9E-10 6.1E-03 August 1.8E-01 1.1E-10 3.6E-03 September 6.8E-02 4.2E-11 1.4E-03 October 6.3E-02 3.7E-11 1.2E-03 November 1.2E-01 7.7E-11 2.6E-03 December 1.4E-01 8.4E-11 2.8E-03 January 2025 1.1E-01 6.4E-11 2.1E-03 February 1.0E-01 6.9E-11 2.3E-03 March 1.8E-01 1.1E-10 3.6E-03 April 2.3E-01 1.4E-10 4.7E-03 May 2.3E-01 1.4E-10 4.6E-03 June 2.1E-01 1.3E-10 4.3E-03 C.
Radioactive Solid Waste Disposal During the reporting period, no non-compacted solid waste was transferred to the WSU Radiation Safety Office for packaging and disposal.
- 7.
Personnel and Visitor Radiation Doses The quarterly doses of the WSU Nuclear Science Center reactor staff and experimenters are given in Table V. The maximum quarterly dose to a reactor staff member was 60 mrem, whole body. A total of 1,648 individual persons visited the 2 Quantity released based on 4500 CFM effluent of ventilation system in AUTO mode of operation. Concentration after dilution is based on 10 CFR 20 effluent release limit of 1.0 x 10-8 µCi/mL for Ar-41 (Table 2, Col.1), and a dilution factor of 3.4 x 10-3 (WSU Technical Specifications 3.5.2). DAC limits are based on 10 CFR 20 derived air concentration limit of 3.0 x 10-6 µCi/mL for Ar-41 (Table 1, Col. 3) and a dilution factor of 3.4 x 10-3.
2025 Annual Report Washington State University Nuclear Science Center Page 7 of 14 Nuclear Science Center during the reporting period, of which 472 entered a controlled access area (CAA).3 A total of 48 group tours, consisting of 348 individuals, visited the center during the reporting period, also entering a CAA. None of these tour groups received measured exposures above 0.1 mR as determined by digital pocket dosimeters.
3 A controlled access area is an area in the building where radioactive materials are used or stored and is a part of the licensed reactor facility.
2025 Annual Report Washington State University Nuclear Science Center Page 8 of 14 Table V.
Quarterly Reactor and Experimenter Staff Dose4 (mrem)
Badge No.
Q3 2024 Q4 2024 Q1 2025 Q2 2025 07990 M
M 17 07398 4
2 M
32 01340 9
11 M
15 07441 23 6
10 29 07991 M
M 29 07985 1
M 20 07992 M
M 19 03396 3
6 5
24 01327 M
07983 M
M 19 01160 10 5
M 18 08141 M
M M
14 07993 M
M 14 07961 42 22 20 60 07393 4
7 M
20 07981 M
M M
03652 3
M 9
36 07393 M
M 5
03768 M
M M
M 07379 M
M 5
38 07882 15 07349 M
07884 3
5 M
13 07987 M
M 23 03651 M
M M
17 07988 M
M M
07982 M
M 07429 M
1 M
29 07396 2
M M
M 03962 M
M 09171 49 07117 M
M M
12 07986 M
M 07402 M
M M
13
- 8.
Reactor Facility Radiation and Contamination Levels The limit of quantification (LOQ) for building removable contamination determination survey samples as measured by liquid scintillation assay is 8.77 x 10-8 Ci/cm2; the 4 -- denotes data not available either due to departure from the facility or new personnel starting at the facility. An M denotes that the dosimeter reading was less than or equal to the background radiation level for that quarter.
2025 Annual Report Washington State University Nuclear Science Center Page 9 of 14 survey sample data that was collected for removable contamination determination were averaged over one year. Routine building surveys showed average levels of removable activity to be less than the LOQ for all non-CAAs.
Table VI.
Average Removable Contamination for Weekly Monitoring in CAAs and Non-CAAs5 Location Measured Activity Above LOQ
(µCi/cm2) 201 B M
201A M
201 RX BRIDGE STEPS M
201 HAND FOOT MONITOR M
201 RX BRIDGE - SOUTH M
201 RX BRIDGE - NORTH M
201 EXPERIMENTER PLATFORM M
201 BENCHES M
201 FLOOR SOUTH M
201-C HEAT EXCHANGER FLOOR M
201 FLOOR NORTH M
106 ION EXCHANGER PIT M
101-A PURIFICATION PUMP PIT M
101 DOOR WAY M
101 SAMPLE PREP BENCH M
101 SAMPLE STORAGE M
101 HOOD #1 M
101 HOOD #2 M
RAM STORAGE SAFE M
101 ISLAND M
101 NORTH LAB BENCH M
101 HOOD #3 M
101 HOOD #4 M
101 SHIPPING BENCH M
B21 PANORAMIC IRRADIATOR M
B21 FLOOR M
RM 2 SOUTH FLOOR M
RM 2 THERMAL COLUMN M
RM 2 THERMAL COLUMN FLOOR M
RM 2 NORTH FLOOR M
RM 2 WEST CAVE FLOOR M
RM 2 EAST CAVE FLOOR M
5 Bolded text indicates a non-CAA. Regular text indicates a CAA. M indicates the value is below the LOQ value of 8.77 x 10-8 Ci/cm2.
2025 Annual Report Washington State University Nuclear Science Center Page 10 of 14 The results for the routine area radiation surveys of the building in CAAs and non-CAAs are given in Table VII. The highest average dose rate for a single location in a CAA was 11.28 mrem/hr, which occurred in Room 2 East Cave. This value is less than the limit for CAAs. The lowest average dose rate in a CAA was 0.04 mrem/hr (a level considered background), which occurred a number of locations surveyed. The average dose rate in the radiochemistry sample hoods (a non-CAA) was 0.09 mrem/hr.
The East and West Cave are secured storage areas that are designed to house radioactive sources, and provide shielding. The space is posted as a high radiation area. Personnel do not typically work in this area and it is locked when not in use.
Table VII.
Average Radiation Dose Rates for Weekly Monitoring in CAAs and Non CAAs6 Location Average Dose Rate (mrem/hr)
ROOM 201 B 0.04 ROOM 201 A 0.04 ROOM 201 BRIDGE 0.57 ROOM 201 BENCHES 0.21 ROOM 201 SOUTH 0.15 ROOM 201 EAST 0.19 ROOM 201 C HEAT EXCHANGER 0.07 ROOM 201 NORTH 0.17 ROOM 106 ION EXCHANGER PIT 0.78 ROOM 101 A PURIFICATION PIT 1.61 ROOM 101 DOORWAY 0.04 ROOM 101 SAMPLE PREP BENCH 0.04 SAMPLE STORAGE 0.07 ROOM 101 SAMPLE DROP HOOD 0.04 ROOM 101 HOOD 1 0.12 ROOM 101 HOOD 2 0.18 101 NORTH LAB BENCH 0.14 101 HOOD #3 0.04 ROOM 101 HOOD 4 0.04 ROOM 101 SHIPPING BENCH 0.04 ROOM B21 PANORAMIC IRRADIATOR 0.04 ROOM 2 SOUTH 0.20 ROOM 2 THERMAL COLUMN 0.04 ROOM 2 NORTH 0.09 ROOM 2 WEST CAVE 0.72 ROOM 2 EAST CAVE 11.28 6 Bolded text indicates a non-CAA. Regular text indicates a CAA.
2025 Annual Report Washington State University Nuclear Science Center Page 11 of 14
- 9.
Environmental Monitoring Program The environmental monitoring program is used to determine the offsite background radiation levels; thermoluminescent dosimeters (TLDs) are used to make the measurements. The offsite radiation monitoring program is required by the Technical Specifications. The TLDs that are used for offsite monitoring are designated as TLD numbers 3, 7, 9, 15 through 35, and 39 through 44. The average background radiation level is then compared to the nearest occupied dwelling.
Average quarterly dose rates for offsite locations are listed in Table VIII and are used to calculate the Technical Specification threshold of 20% above the background radiation level and compared to the limiting values which are listed in Table XI. The average environmental radiation levels for the closest offsite point of extended occupancy is listed in Table X. Table IX shows the quarterly environmental radiation levels for those TLDs located at onsite locations. The onsite locations are not required to be compared to background radiation levels.
The closest offsite points of extended occupancy are compared in Figure 1 to both the background radiation levels and the 20% above background radiation levels. The ALARA effluent release limits in Technical Specification 3.5.2(3) specify that annual radiation exposure due to reactor operation, at the closest offsite extended occupancy, shall not, on an annual basis, exceed the average offsite background radiation by more than 20%. For the reporting period, the average background radiation dose rate for off-site locations was 0.40 mrem/day, while the average radiation dose rate at the closest extended occupancy area 600 meters away was 0.38 mrem/day. This result indicates that no exposure level above normal background radiation were found, and that no dose levels exceeded Technical Specifications requirements for an offsite area of extended occupancy.
2025 Annual Report Washington State University Nuclear Science Center Page 12 of 14 Table VIII.
Environmental Radiation Levels at Offsite Locations7,8 Location Q3 2024 Q4 2024 Q1 2025 Q2 2025 Average Fence E of NSC 0.40 0.38 0.39 0.37 0.39 Fence, N of Rad Waste Shed 0.43 0.42 0.54 0.46 0.46 Fence directly N Rad Waste Shed 0.53 0.52 0.64 0.46 0.52 S NSC, on parking lot fence 0.38 0.35 0.35 0.37 0.36 Fence S Roundtop Dr, 10th pole W of pole C14 0.45 0.40 0.40 0.41 0.42 Telephone pole C12 0.49 0.42 0.42 0.51 0.46 Telephone pole near golf course gate 0.45 0.43 0.43 0.44 0.43 E across fairway on pine tree 0.37 0.36 0.36 0.38 0.37 Maple tree #54 along driving range 0.43 0.37 0.37 0.37 0.40 NW to fence uphill from driving range 0.41 0.43 0.43 0.42 0.41 Follow fence E to fence corner 0.45 0.44 0.44 0.43 0.43 S to lone spruce tree near water hazard 0.43 0.44 0.44 0.42 0.41 Roundtop hill park, NW fence corner 0.36 0.35 0.35 0.42 0.38 Deciduous tree edge of 18th green 0.37 0.43 0.43 0.41 0.40 6ft pine tree, 3rd W down cart path from clubhouse 0.39 0.39 0.39 0.43 0.39 3rd to last tree after gap in same line of trees 0.35 0.36 0.36 0.34 0.34 SW to fence along path near 2nd to last tee box at bottom hill 0.40 0.39 0.39 0.38 0.38 Follow fence partway up hill after fence turns S 0.41 0.40 0.40 0.44 0.40 Follow fence, 15th pole E after fence turns W 0.43 0.38 0.38 0.41 0.40 Follow fence about halfway between last TLD and corner 0.41 0.44 0.44 0.37 0.41 Largest bush S of NSC 0.41 0.40 0.40 0.46 0.42 2nd fence S NSC, W end at gate 0.41 0.39 0.39 0.38 0.38 S Fairway Rd, 1st light post on right 0.39 0.35 0.35 0.44 0.40 S Fairway Rd, 2nd light post on right 0.39 0.42 0.42 0.40 0.41 Ellis Way and Hog Lane sign 0.37 0.37 0.37 0.37 0.37 Bottom of radio antenna hill, fence next to shrub left of gate 0.33 0.37 0.37 0.35 0.35 3rd fence S of NSC, SE corner, cow pasture 0.43 0.42 0.42 0.43 0.41 Airport fence W end runway at gate 0.45 0.44 0.44 0.47 0.44 Fence/entry bar E of Jewett Observatory 0.41 0.34 0.34 0.33 0.37 Railing at Terrell Mall / Library 0.38 0.38 0.38 0.41 0.38 7 Offsite defined by the Technical Specification 1.0 and 5.1.1 as any location, which is outside the site boundary. The --
indicates a TLD which was missing.
8 Dose rate in mrem/day.
2025 Annual Report Washington State University Nuclear Science Center Page 13 of 14 Table IX.
Environmental Radiation Levels at Onsite Locations9,10 Location Q3 2024 Q4 2024 Q1 2025 Q2 2025 Average E lower loading dock 0.41 0.39 0.39 0.37 0.39 Pool room truck door fence S end 0.72 0.74 0.54 0.62 0.66 Pool room truck door fence N end 0.87 0.78 0.63 0.69 0.74 E wall rad waste shed 0.58 0.54 0.52 0.49 0.53 N wall rad waste shed 0.70 0.64 0.56 0.48 0.60 Cooling tower fence, NE corner 1.10 1.00 1.03 0.99 1.03 Room 101 window 0.51 0.43 0.48 0.51 0.48 Railing next to upper liquid waste tank 0.48 0.45 0.42 0.43 0.45 Room 2 truck door fence 0.41 0.38 0.42 0.42 0.41 Transformer vault vent louvers 0.46 0.45 0.46 0.46 0.46 NSC main entrance, light fixture 0.52 0.51 0.49 0.47 0.50 NSC roof, pool room vent stack 0.35 0.35 0.37 0.35 0.35 NSC roof, guide wire E end of building 0.42 0.35 0.39 0.40 0.39 NSC roof, E pool room vent support leg 0.61 0.65 0.53 0.79 0.65 NSC roof, air conditioning support leg 0.40 0.42 0.42 0.40 0.41 NSC roof, W pool room vent support leg 0.58 0.67 0.58 1.04 0.72 Table X.
Environmental Radiation Levels for the Closest Offsite Point of Extended Occupancy10 Location Q3 2024 Q4 2024 Q1 2025 Q2 2025 Average Apt complex C, gas meter 0.35 0.36 0.40 0.44 0.39 Apt complex B, gas meter 0.40 0.39 0.39 0.41 0.40 1st fence S apt complex A 0.36 0.35 0.32 0.36 0.35 Table XI.
Background Environmental Radiation Levels10 Description Q3 2024 Q4 2024 Q1 2025 Q2 2025 Average Background radiation levels 0.41 0.39 0.39 0.41 0.40 20% above background radiation levels 0.49 0.47 0.47 0.49 0.48 9 Onsite defined by the Technical Specification 1.0 and 5.1.1 as any location within the site boundary. The -- indicates a TLD which was missing.
10 Dose rate in mrem/day.
2025 Annual Report Washington State University Nuclear Science Center Page 14 of 14 Figure I:
Environmental radiation levels for the closest offsite point of extended occupancy radiation levels as compared to background radiation levels and 20% above background radiation levels.
0.00 0.10 0.20 0.30 0.40 0.50 0.60 Q3 2024 Q4 2024 Q1 2025 Q2 2025 Average Dose Rate (mrem/day)
Quarter Apartment Complex A Apartment Complex B Apartment Complex C
Background
20% Above Background