ML18269A090

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University of California- Irvine, Docket Number 50-326, License Number R-116, Annual Report Submittal in Accordance with Technical Specification 6.7.1
ML18269A090
Person / Time
Site: University of California - Irvine
Issue date: 09/26/2018
From: Wallick J
University of California - Irvine
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML18269A090 (19)
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UNIVERSITY OF CALIFORNIA, IRVINE

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Department of Chemistry 1102 Natural Sciences II University of California, Irvine Irvine, CA 92697-2025 Wednesday, September 26, 2018 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555-0001

SUBJECT:

University of California- Irvine, Docket Number 50-326, License Number R-116, Annual Report Submittal in Accordance with Technical Specification 6.7.1

Dear Sir or Madam:

By way of this letter, the University of California, Irvine is submitting the annual operating report as required by Technical Specification 6.7.l of license number R-116, covering the period of July Pt, 2017 through June 301h, 2018.

Electronic copies are being provided as indicated below.

If you have any questions regarding this matter, please contact me at (949) 824-6082.

Sincerely, than Thomas Wallick Reactor Engineer

Enclosure:

As stated CC with

Enclosure:

  • Ken Janda, Dean of School of Physical Sciences, University of California, Irvine
  • Johnny Eads, Inspector, U.S. Nuclear Regulatory Commission
  • Linh Tran, Project Manager, U.S. Nuclear Regulatory Commission
  • George Miller, Chemistry Department, Reactor Supervisor, University of California, Irvine
  • Athan Shaka, Chemistry Department, Reactor Director, University of California, Irvine
  • Reactor Operations Committee Members, University of California, Irvine
  • American Nuclear Insurance, 95 Glastonbury Blvd., Glastonbury CT 06033, Policy NF-176

2017 - 2018 UC Irvine Nuclear Reactor Facility Annual Report FACILITY LICENSE R-116 - DOCKET NUMBER 50-326 JONATHAN WALLICK l Associate Reactor Supervisor

1 Table of Contents Section 1 Operations Summary ...................................................................................................... 2 Section 2 Data Tabulations for the Period July 1st, 2017 to June 30th, 2018 ............................. 4 Section 3 Inadvertent Scrams, Unplanned Shutdowns, Events at Power ................................. 5 Section 4 Maintenance and Surveillance and Other Incidents ................................................... 6 Section 5 Facility Changes and Special Experiments Approved................................................ 9 Section 6 Radioactive Effluent Release......................................................................................... 10 Section 7 Environmental Surveillance .......................................................................................... 12 Section 8 Radiation Exposure to Personnel. ................................................................................ 15 Section 9 Closing Remarks ............................................................................................................. 17 UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

2 Section 1 Operations Summary Operation of this facility supports UCI research and education programs in the Department of Chemistry (CHEM) and the Department of Chemical Engineering and Material Science (ChEMS).

Research is being conducted in application of radioisotopes as tracers and radiochemical analytical and separation techniques including applications to nuclear waste separations (ChEMS).

Reactor utilization, apart from operator training and maintenance, is for analytical sample irradiation, production of isotopic tracers, and neutron instrument testing. Analysis samples come from diverse origins related to forensic science, fossil fuels, geochemistry, art, and archaeological studies, chemical separations in nuclear fuel cycle experiments, chemical synthesis, industrial quality control, enzyme studies, trace element pollution studies, etc. The reactor is also used in class work by undergraduates learning tracer and activation analysis techniques using small quantities of short-lived activated materials. Enrollment in the Fall Quarter 2017 laboratory course in Radioisotope Techniques using the facility was 23 students with 2 graduate teaching assistants, who also learned these techniques.

Support for UCI faculty and students includes grants from NRC and DOE (NEUP and NSSA),

and partnerships with national laboratories (PNNL, LLNL, LANL, and INL).

Use is also made of the facility by other educational institutions, both for research and for visits/tours. A modest Nuclear Science Outreach program (NSOP) using UCI students to present talks and a laboratory to middle and high school classes has been continued. This program has also involved tours, class demonstrations, and analyses of samples submitted by faculty.

Operations have remained at a higher level as student use and interest has maintained.

Criticality was achieved for 272.22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br />, slightly down from the previous year, and the total energy generated was equivalent to 164.48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> at full steady state power, down slightly from last year due to students combining experiments during the same irradiations. 138 separate experiments were performed, on slightly down from last year as well, and 4832 samples were irradiated. Four moderate level mixed isotope shipments were made, all Yellow II category, totaling 2.07 GBq of activity. Thirteen pulses were performed this year, all without incident, four of which occurred after extensive console maintenance to correct unintended effects on pulsing behavior, described in section four of this report. One 10 CFR 50.59 change has been initiated and completed during the course of the last year. A few unusual maintenance/surveillance results/activities were noted/conducted during this period: a false alarm for the CAM system, REG control rod UP button stuck, several problems with the ATR drive and air systems, cabling and connection failures of the fuel temperature monitoring channel, a flooded in-core terminus, and electrical maintenance on the console to preclude spurious scrams during pulsing. No new experiments have been approved this year, though one, different from last years near approval, is nearing submittal for approval.

A routine NRC inspection June 26th to the 28th of 2018, resulted in no Notices of Violation or follow-up items. In 2016-2017, a Reactor Operations Committee meeting was held on December 12th, 2017 in accordance with Technical Specification requirements.

No follow-ups or incidents have been forthcoming regarding security or emergency response. One emergency drill / exercise has been held this past year involving the UCI EH&S radiological personnel, Orange County Fire Authority, UCI Police Department, Orange County Health Care Agency, California National Guard Hazmat team, and reactor staff and faculty. The exercise was held on September 7th, 2017, to large success, involving all agencies previously named, running tabletop exercises with the entire group.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

3 Inspections/audits continue to be conducted quarterly by the Radiation Protection staff of EH&S at UCI. These have identified that frequency schedules have been properly maintained, and results continue to show absence of significant levels of contamination or personnel exposure. Our new radiation safety division has been in a state of flux for the past two years, mainly due to funding issues that are partially resolved.

No new operator trainees underwent training this year, but one current RO took the NRC examination on December 5th, 2017, resulting in his upgrade from RO to SRO. As of June 30th 2017, 6 SROs and 5 ROs were licensed. One SRO and three ROs are currently inactive.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

4 Section 2 Data Tabulations for the Period July 1st, 2017 to June 30th, 2018 TABLE I - General Information Experiment Approvals on file 5 Experiments performed (including repeats) 138 Samples irradiated 4832 Energy generated this period (Megawatt hours) 41.12 Total, 69 element core = 127.00

>74 element core = 1660.13 Total energy generated since initial criticality 1787.13 Mwh Pulse operation this period 13 Total reactor pulses to 6/30/2017 1037 Hours critical this period 272.22 Total hours critical to date 10501.83 Inadvertent scrams or unplanned shutdowns or events at power 2 Visitors to reactor - as individuals or in tour groups - 1004 Maximum dosimeter recorded for visitors - all less than 0.2 mrem Visiting researchers (Temporary Self Indicating Dosimeters) 45 Maximum exposure recorded at one visit 5.2 mrem Visiting researchers (Thermoluminescent Dosimeters) 56 Students and teaching assistants in class, badged 23 Exposures reported for class (range: 0-3 mrem) average 10.8 mrem Isotope Shipments this Period (Mixed Activation Products = 0.056 Ci total) 4 TABLE II - Reactor Core Status 06/30/18 (Core configuration changed as of 01/18/18)

Fuel elements in core (including 2 fuel followers) 84 Fuel elements in storage (reactor tank - used) 23 Fuel elements unused (4 instrumented elements + 1 element + 1 FFCR) 6 Graphite reflector elements in core 32 Graphite reflector elements in reactor tank storage 2 Water filled fuel element positions 4 Experimental facilities in core positions 5 Non-fueled control rods 2 Total core positions accounted for 127 Core excess, cold, no xenon (as of 6/30/2018) $2.84 Control Rod Worths (Calibrated 01/22/2018) REG $2.92 SHIM $3.49 ATR $1.79 FTR $0.69 Total: $8.89 Maximum possible pulse insertion (calculated) $2.48 Maximum peak power recorded 1038 MW Maximum peak temperature recorded in pulse (B-ring) 354.3 °C UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

5 Section 3 Inadvertent Scrams, Unplanned Shutdowns, Events at Power TABLE III Date Time Power Type and Cause 2017 07/14 13:18 1.5 W Period scram. The Wide Range Monitor initiated a period scram during a start up to full power. At a period of 3.2 seconds, the scram occurred, dropping all control rods and placing the reactor into a safe condition. Troubleshooting was performed and root cause of the failure was determined to be a stuck button, the REG UP button, and operator error in the individual not responding quickly enough to correct the condition. The event was not found to be reproducible, though the operator was cautioned to be more aware of such events and immediately depress the DOWN buttons for both SHIM and REG in such an event. Restart was authorized by the SRO. This is the first occurrence since the button was replaced on August 31st, 2016. Given the measures taken to prevent recurrence, this cause seems to be a design flaw of the control buttons of the TRIGA control console.

08/24 07:58 250 kW Linear scram. The linear power monitor initiated a scram while stable at a power level of 100% of the 250 kW range. All control rods dropped and the reactor was put into a safe condition.

Troubleshooting was performed and the root cause of the occurrence was determined to be physical contact with the Wide Range Linear Monitor, specifically the Full Power Gain Adjust potentiometer. The potentiometers setting was verified to be as previously set during power calibration. The event was not found to be reproducible, though personnel in the control room were cautioned to be more careful of their location and proximity to delicate equipment. Restart was authorized by the SRO.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

6 Section 4 Maintenance and Surveillance and Other Incidents The following non-routine maintenance/surveillance activities were carried out during this period.

Any reactor operation related items have been included above and are not repeated here.

2017 07/17 At 1805 on July 17th, 2017, a high CAM alarm was received by the local police department. An SRO was called in immediately and made entry to the facility after ensuring it was radiologically safe to do so. Status of the CAM and area radiation monitors was checked and levels were verified to be normal. A trouble call was made to check the functionality of the alarm reporting system, which was found to be the source of the false alarm and was immediately corrected.

08/17 On August 17th, 2017 at 0700 during routine rod checks, the ATR was found to be rising slowly in the 000 to 150 indicated range of motion, with one stall occurring in the noted range. Troubleshooting was performed and it was determined that a clean, inspect, and lubrication would be completed before further reactor operation would be permitted. Over the next several days, several problems were found and remedied by August 23rd, 2017, including: partial bearing failure in the ATR drive motor, necessitating replacement and cleaning of the motor; broken wires on two of the limit switches on the drive, LS2A and LS2B, necessitating in removing the switch, cleaning the terminals, preparing and soldering the wires in position; a damaged position indicating potentiometer, which was subsequently replaced with the correct part; and motor misalignment, which was then correctly aligned to prevent further biding on the mount. Rod drop tests were then performed satisfactorily and full operability was also confirmed. Reactor operation was permitted again on August 23rd, 2017 at 1345.

09/19 On September 19th, 2017, at 1202 after a manual scram of the reactor, the ATR drive stalled during downward motion at indicated position 160. Motion of the ATR rod was not affected and was fully inserted upon the manual scram action. Further operation was then prohibited. Troubleshooting performed on September 27th, 2017, revealed that the motor has become misaligned once again, placing additional load on the motor, which it could not overcome at its full rated torque of 1/60th HP.

Realignment was achieved and rod drop tests were conducted once again, satisfactorily. Reactor operation was then permitted on September 27th, 2017 at 1215.

10/17 During a morning walkthrough on October 17th, 2017, at 0720 one of the fuel element temperature channels was observed to be malfunctioning, indicating 400 °C during shutdown conditions while the other two channels indicated approximately 20 °C. Reactor operation was then prohibited as troubleshooting efforts began.

Investigation revealed issues related to the cabling and connections between the instrumented fuel element (IFE). In order to facilitate replacement and work on the UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

7 Amphenol connector on the top end of the IFE, the IFE was removed from the core and placed in a storage location on the side of the pool, with the fueled portion approximately 10 feet under water. From October 17th, 2017 to October 19th, 2017, the Amphenol plug, Amphenol socket, and wiring from the Amphenol to the control console was completely replaced. The IFE was placed back into the core in its original position on October 19th, 2017 and a fuel temperature calibration was performed at 1345 the same day. A power test was conducted on October 20th, 2017 to verify proper tracking of fuel temperature to 5 kW, which was successful, and further up to 250 kW, which was also fully successful. Normal reactor operation was once again permitted on October 20th, 2017, at 0916.

10/19 On October 19th, 2017, at 1545, the Fast Transfer System (FTS) normal lined terminus was cleaned to reduce the amount of contamination of fissionable materials in the terminus. The contamination was from small amounts of fissionable materials in the micro to nanogram ranges contained in samples run in the system.

The sensitivity of the system requires the freedom from trace contamination. Using an approved cleaning program, the terminus was flushed with stages of RadiacWash, deionized water, isopropyl alcohol, and pressurized air. Quantitative characterization of the recovered washes indicated a reduction in contamination by a factor of approximately 50. All materials were collected and disposed of as radioactive waste.

12/11 At 0605 on December 11th, 2017, the ATR drive became stuck at indicated position 009 during daily rod functional checks. A loud venting sound became apparent upon the drives immobilization, and the control rod was indicated and observed to be in the fully down position. Operations were suspended to allow further investigation.

Troubleshooting revealed that a set screw had loosened, allowing the externally threaded cylinder to unscrew from the air inlet assembly of the ATR drive, resulting in complete venting of air pressure from the control rod drive. The cylinder was reconnected to the air inlet assembly and the offending set screw tightened to prevent recurrence. Rod drop tests were performed satisfactorily and reactor operation was authorized at 1443 on December 11th, 2017.

2018 01/08 On January 8th, 2018, the quinquennial maintenance event of fuel checks and measurements began, concluding on January 18th, 2018. Five elements were removed from service and replaced with elements of similar burn up from in pool storage. The elements that were removed from service had atypical surface scratching and damage when compared to other elements, though there was no indication of a past or impending fission product leak. The decision was purely conservative to avoid potential future issues and have these elements more fully characterized before re-admittance to service. Methods involving quantitative physical surface inspections, instead of only visual ones, will be utilized to fully assess the elements in question.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

8 02/16 On February 16th, 2018, at 1354 the in core cadmium lined fast transfer system (FTS) terminus was found to be flooded when testing was attempted with the device during shutdown reactor conditions. Reactor operations were prohibited and the reactor supervisor, reactor director, and reactor operations committee were informed of the occurrence. Prior to this finding and after the conclusion of fuel checks on January 18th, 2018, the system had been successfully utilized, transferring samples into and out of the core using this terminus, suggesting that the leak occurred as a consequence of usage rather than physical shock from handling during the fuel checks. Core excess was estimated to have changed by +$0.11 due to the additional water in place of void in core. Upon reactor operations committee and reactor supervisor approval, operations were permitted on February 20th, 2018, given that the flooded terminus violated no technical specifications, allowing the terminus to remain in position. Core excess, performed at 0652 on February 20th, 2018, revealed that no reactivity change had taken place, most likely as a result of the cadmium layer in the terminus depressing flux and reducing the effect of the internals of the sample chamber. Efforts immediately began to replicate the defective terminus for replacement in core. On April 17th, 2018, an identical terminus was installed in place of the flooded terminus, resulting in a core excess change of approximately +$0.02, most likely due to the replaced cadmium layer, which had undergone appreciable burn up over the 30 year period that the defective terminus had remained in place.

06/08 On June 8th, 2018, June 18th, 2018, and June 19th, 2018, maintenance on the console electrical system was conducted in order to restore proper functionality to the pulsing mode of reactor operation. Prior to these maintenance activities, whenever a pulse was fired, several scrams (Linear Power, Percent Power, Period, and High Voltage) would occur upon firing the pulse rods, resulting in clipped, incomplete pulses. The root cause of these spurious scrams was an incomplete installation plan and execution of instrumentation installed in 1994, when the original General Atomics channels of reactor power indication were replaced by a trio of Gamma-Metrics fabricated channels. These scrams that were occurring were not required by the technical specifications in pulse mode, aside from one channel of High Voltage versus the three that were in effect, so efforts were made to remedy this problem.

At conclusion of the maintenance several test pulses were fired, resulting in correctly shaped pulses of larger magnitudes than previously observed.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

9 Section 5 Facility Changes and Special Experiments Approved One 10 CFR 50.59 changes have been initiated and completed during the course of the last year.

The single screening form was completed to amend the startup and shutdown checklists to reflect changes in the SRO level staffing of the operations group, as well as to remove a differential conductivity check which was proving confusing to operators and trainees, which was not required by technical specifications or SOPs.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

10 Section 6 Radioactive Effluent Release (a) Gases The major direct release to the environs is Argon-41 produced during normal operations.

Very small amounts of other gases may be released from irradiated materials in experiments.

Releases are computed based on original measurements at point of origin within the facility and taking only dilution into account. Since much of the release is from operation of the pneumatic transfer system for samples, this is a conservative estimate in that assumption is made that all use of the PT is at full steady state power level (250 kW) when, in fact, considerable use is with the reactor at a lower power level. In view of the small numbers involved, and the fact that an integrated dose check is provided by an environmental dosimeter (CaSO4-Dy) hanging directly in the exhaust at the point of stack discharge, it is considered unnecessary to provide further checks of these estimates. The dosimeter data confirm that an individual standing directly in the exhaust flow for one year would receive an additional submersion dose from the exhaust less than the reliability limit of the dosimeters, or less than 20 mrem per year. The dosimeter data are presented separately in Section 7, Table IV. Over the years that data have been collected, the accumulated exposure at the exhaust locations have been lower than for "control" points because of lower masses of concrete structures in the vicinity. In fact the data have been consistently at 20-25 mrem per year below background level, so confidence of exposure less than 5 mrem over background seems plausible.

Release estimates based on operational parameters are as follows:

(1) Operation of pneumatic transfer system (07/01/2017-06/30/2018):

a. Minutes of operation: 471.1 minutes
b. Release rate assumed: 6.0 x 10-8 microcuries/mL
c. Flow rate of exhaust air: 1.2 x 108 mL/min
d. Dilution factor: 0.01 Total release computed: (a x b x c x d) = 3.39 x 101 microcuries (2) Release from pool surface (07/01/2017-06/30/2018):
a. Total hours of operation at full power (EFPH) = 164.48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />
b. Release rate assumed: 1.0 x 10-8 microcuries/mL
c. Flow rate of exhaust air: 1.2 x 108 mL/min
d. Dilution factor: 0.01 Total release computed: (a x 60 x b x c x d) = 1.18 x 102 microcuries
e. Total of (1) and (2) emission in 1 year = 1.52 x 102 microcuries
f. Total effluent released in 1 year (525960 minutes/yr. x c x d) = 6.31 x 1011 mL Concentration averaged over 12 months (e/f) = < 2.41 x 10-10 microcuries/mL

-9 Since 2 x 10 microcuries/mL provides an annual exposure for constant immersion of 10 mrem, this corresponds to < 2.0 mrem potential additional radiation exposure to an individual standing in and breathing in the effluent stack for the entire year.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

11 Additional note: Exhaust is diluted by a factor of 100 before release and the mixed plume is released at approximately 100 feet above the roof level (200 feet above surrounding ground, granting even greater dilution).

(b) Liquids and Solids Liquid and solid wastes from utilization of by-product materials are disposed through a university contract. Waste is transferred to the custody of UCI Environmental Health and Safety (EH&S). Disposals to this custody are given below. It is important to note that activity values are estimated at the time of transfer to EH&S control. Since few shipments are being made from campus, decay to negligible levels occurs for all medium-lived radionuclides. Teaching course items (used for training in liquid scintillation counting techniques) may be a mixture of reactor generated byproducts and purchased materials (exclusively 14C and 3H).

DRY WASTES:

Five transfers of 2 cubic foot containers of dry waste were disposed during this period (07/01/2017 through 06/30/2018), estimated at a total quantity in 10 cu ft of 10.20 microcuries of mixed activation products (measured as 60Co equivalent at time of transfer).

LIQUIDS:

No transfers of liquid constituent were made this year.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

12 Section 7 Environmental Surveillance Calcium Sulfate/Dysprosium thermoluminescent dosimeters are in place at 12 locations around the UCI Campus for environmental monitoring purposes. These are provided by Mirion Technologies, Irvine, California (formerly Global Dosimetry Systems). The environmental packs have three chips in each pack which are averaged for exposure recording. Mirion runs multiple control samples in addition to the locations listed below. All dosimeters are housed in small metal lock-boxes (except for locations 10 and 12). The table below lists the locations.

Routine contamination surveys consisting of wipe tests and G-M surveys have shown mostly a clean facility with significant, removable contamination only in areas coming into direct contact with samples removed from the reactor, and on sample handling tools. Trash is surveyed before disposal and not disposed of unless found to be free of removable and fixed contamination.

List of Locations for Environmental Dosimeter Packs

1. South Reactor Facility Perimeter
2. West Reactor Facility Perimeter
3. North Reactor Facility Perimeter
4. Reactor Facility Main Air Exhaust
5. Rowland Hall, First Floor Hallway Over Reactor Facility
6. McGaugh Hall Top Floor
7. Langson Library Top Floor
8. Reines Hall Top Floor
9. Reactor Facility Emergency Exhaust Duct
10. On-campus Housing
11. Rowland Hall Building Fume Hood Exhaust Duct
12. Engineering Tower Room 521 UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

13 TABLE IV - Environmental Dosimetry Data 2017-2018 Average Total Exposures in mrem (including control background)

Quarter Location 2017 2017 2017 2018 Annual Prior Year Above Control Q2 Q3 Q4 Q1

1. S. Facility Perimeter 28 29 31 30 118 152 +18
2. W. Facility Perimeter 48 27 28 29 132 129 +32
3. N. Facility Perimeter 29 33
  • 34 130 114 +30
4. Facility Main Air Exhaust 17 20 23 22 82 94 -18
5. Hallway Over Facility 20 22 24 24 90 99 -10
6. McGaugh Hall Top Floor 21 25 25 25 96 105 -4
7. Langson Library Top Floor 26 30 31 31 118 127 +18
8. Reines Hall Top Floor 22 24 27 25 98 110 -2
9. Facility Emer. Exhaust 19 20 22 22 83 94 -17
10. On-Campus Housing 20 21 24 24 89 97 -11 11 Facility Fume Hood Exh. 18 20 22 22 82 94 -18 12 Engineering Tower 521 20 21 22 22 85 99 -15 Background Control 23 24 27 26 100 112 0
  • Dosimeter reported lost by vendor. Conservatively estimated at 34 mrem to match highest reading this year.

Discussion Raw data is presented here, along with controls and prior year comparisons. Within this range, the data vary relatively little. Locations on walls bordering the facility, such as 1, 2, 3, are usually the highest, remote locations, such as 10, 11, and 12, are the lowest. Data for this year reflects several issues:

  • Location 7 is on the top floor of a large building and may experience greater cosmic flux, as well as concrete releases. This has been a trend continuing for five years now.
  • Location 1 near the facilitys gamma irradiator, which has been in greater use this reporting period, as well as a lead cave which continues to store a high activity load.
  • Location 2 is on the other side of a location in the reactor facility temporarily used for source storage.
  • Location 3 is located on the other side of a concrete wall from the ion exchange resin tanks and a source storage lead cave, both of which have moderate levels of activity. This location is also now home to a newly constructed radiation use laboratory, which may be contributing to the increased dose readings.

Exposure estimated to a single individual in an uncontrolled area at this facility is minimal. With the exception of three locations near the facility, all dosimetry associated with exposures from the facility indicates lower than control levels. Locations 1 and 2 are in hallways with extremely minimal occupancy or travel, especially since security policy is to maintain permanently locked doors to the hallways on this floor level (access only with building keys), and location three is in an adjacent radiation use laboratory. The rooms overhead (location 5) are casually occupied by very UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

14 few individuals (one or two at the most) in the space above the reactor core. The air released from the facility/building (measured by locations 4, 9, and 11) continues to give no detectable exposure above background. Over many years, the data at each specific location has shown remarkable consistency. The net conclusion is that, within precision of measurement, and compared to distant control areas (numbers 7 and 10), we are operating with very minimal levels (within statistical error of zero) of potential (full 24/7 occupancy) public exposure over normal background levels.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

15 Section 8 Radiation Exposure to Personnel.

UCI issued TLD badges to students or researchers regularly utilizing radiation. Finger dosimetry (TLD) rings are also issued to personnel who might be regularly handling radioactive sources. TLDs are read quarterly by Mirion Technologies, and results are presented in Table V. Data are for 4 quarters of operations since April 1, 2017. Reporting categories are deep, eye, shallow, and neutron. Other individuals visiting or casually working in the facility were issued Dosimans or Dosicards for which results are shown in Table VI. 42 persons were issued TLD badges on a continual basis; 42 were also issued with finger TLDs. 23 students in a radioisotope techniques class were TLD badged. The two teaching assistants for the course were part of the 42 persons already documented. Reported exposures for the Radioisotopes Techniques class rose above normal values this period, likely due to improper storage of dosimetry by teaching assistants, contrary to last year, averaging 10.8 mrem each person for the quarter.

Table VI also lists all visiting individuals that were issued with Dosimans or Dosicards that record in units of 0.1 mrem. In the course of a few hours, a worker can accumulate 0.2 mrem. A tour visitor usually accumulates 0.0 or 0.1 mrem during a 45 minute visit to the facility. Any reading above 0.2 mrem is tabulated separately.

TABLE V Personnel Exposure Report Summary for 12 months: 04/01/2017 to 03/30/2018 (in mrem)

Whole Body Ring Group Individuals Deep Eye Shallow Neutron Shallow A 16 43 45 52 0 1183 B 5 11 11 14 0 21 C 19 28 29 29 0 27 D 25 270 273 273 215 0 Total 65 352 358 368 215 1231 TABLE VI Non-Zero Data from Dosicards / Dosimans Issued to Workers / Visitors in Addition to TLD badges Avg. Admissions Total Dose Group Persons (per person) (mrem)

A 45 4 28.9 C 82 1 0.9 E 698 1 0.2 Total 825 1004 30.0 Group A: Activation Personnel: individuals doing extensive or casual activation analysis and radiochemical work at the facility. Most of the exposure is a result of Cl-38 or Al-28 radioactivity production.

Group B: Workers: individuals receiving exposure as a result of shipping isotopes, and/or calibration activities in the facility.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

16 Group C: Inactive / Other: individuals who did enter but not carry out radiation related activities during this period, therefore any exposure reported is an indication of range of general background/precision where the badges are stored when not in use.

Group D: Class Students: reported for students and teaching assistants in Radioisotope Techniques class Sep-Dec 2017. Note badges kept 24/7 in laboratory room. All also ran samples by NAA as well as worked with sealed sources.

Group E: Tourists: issuing one dosimeter each for groups of up to 10, and 10 randomly for larger groups. No readings > 0.2 mrem were recorded.

Personnel exposures continue to be very low at this facility in keeping with ALARA efforts.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

17 Section 9 Closing Remarks Overall, the facility continues to function at a high rate of utilization, declining slightly from last year, but still elevated compared to previous years. Numerous moderately severe maintenance activities were necessary this period, but given that the facility is entering its 50th year of operation, such things are expected, though time consuming. Waste generation and disposal has remained at its traditionally low values, given the low power of the reactor and the capacity for short term storage of materials. Radiation exposure to personnel also remains remarkably low, attributing most dose absorbed to the primary activation analysts of the facility and associated laboratories.

Strategic planning for the facility places a license amendment request in the near future (one to two years) for an increase of steady-state power levels to at least 1 MW, in order to improve the sensitivity of NAA conducted at the facility as well as expand capabilities to appeal to a broader user base.

UC IRVINE NUCLEAR REACTOR FACILITY ANNUAL REPORT l FACILITY LICENSE R-116 - DOCKET NUMBER 50-326

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