ML18016A051

2017 Annual Report for the U.S. Geological Survey Triga Non-Power Reactor Facility

ML18016A051
Person / Time
Site:	U.S. Geological Survey
Issue date:	01/11/2018
From:	Roy B US Dept of Interior, Geological Survey (USGS)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML18016A051 (7)

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• usGs science for a changing world Department of the Interior US Geological Survey Box 25046 MS-974 Denver CO, 80225 January 11, 2018 U.S. Nuclear Regulatory Commission Document Control Desk Washington DC 20555

Dear NRC staff,

Enclosed is the 2017 annual report for the U.S. Geological Survey TRIGA non-power reactor facility.

The facility docket number is 50-274.

Sincerely, Brycen Roy Reactor Supervisor Enclosure Copy to:

Geoffrey Wertz OWFN 12 D20

U.S. GEOLOGICAL SURVEY TRI GA REACTOR ANNUAL REPORT JANUARY 1, 2017 - DECEMBER 31, 2017 NRC LICENSE No. R-113 DOCKET NO. 50-274 I. Personnel Changes:

Tim DeBey resigned from the reactor facility effective December 9, 2017.

II. Operating Experience The Geological Survey TRIGA Reactor (GSTR) was in normal operation for the year 2017. No major facility changes were made during the year.

A synopsis of irradiations performed during the year is given below, listed by the organization submitting the samples to the reactor staff:

Organization Number of Samples USGS-INAA 159 USGS - Geochronology 811 USGS - other 22 Non-USGS 2417 Total 3409 A. A thermal power calibration was performed in October, with adjustments made to the instrumentation as required.

B. During the report period, 193 daily checklists and 12 monthly checklists were completed in compliance with technical specifications requirements for surveillance of the reactor facility.

C. Tours were provided to individuals and groups during the year for a total visitor count of approximately 780.

Ill. Tabulation of Energy Generated MWh operated Critical hours Pulses Jan 32.683 35h 49m 0 Feb 24.032 25h 20m 0 Mar 71.117 73h 10m 0 Apr 28.891 31h 06m 2 May 35.015 36h 57m 0 June 120.800 122h 26m 0 July 66.535 69h 34m 0 Aug 103.118 105h 39m 1 Sept 26.266 31h 06m 0 Oct 28.719 43h 10m 4 Nov 23.819 31h 30m 0 Dec 58.206 59h 34m 0 Totals 619.201 665h 21m 7 IV. Unscheduled Shutdowns Five (5) unscheduled shutdowns occurred in 2017. These were:

Number Date Cause 1133 07/19/17 Loss of communication; CSC shut down due to overheating from CPU fan failure 1134 09/20/17 NPP1000 high power due to short in shim 2 rod drive 1135 10/10/17 Loss of building 15 power, operator scrammed reactor 1136 10/26/17 DAS watchdog scram; cause could not be identified 1137 12/04/17 DAS watchdog scram; cause could not be identified V. Significant Maintenance Operations 01 /17 Replaced PVC on purification system pump suction 01/17 Changed 4 prefilters for hood exhaust system 02/17 Replaced CPU fan in CSC computer 02/17 Replaced 3.6V battery in NM1000 05/17 Replaced solenoid valve for bubbler 06/17 Replaced pressure switch on primary pump discharge pipe 06/17 Replaced trim pots for NM1000 Campbell unit Hi and Lo test points 07 /17 Replaced electrolytic capacitors and potentiometers in ratemeter and amplifier modules of Ar-41 NIM modules 08/17 Changed Sensoray board 2 in the DAC computer 2

09/17 Replaced evacuation alarm switch 09/17 Replaced ion exchange resin 09/17 Replaced incandescent bulbs with LEDs in illuminated paddle switches on console 09/17 Calibrated the conductivity meter 10/17 Replaced the flow meter on the purification system 10/17 Replaced 1-turn potentiometer with 10-turn potentiometer in bulk water temperature test circuit 11/17 Replaced regulating rod translator unit 11/17 Replaced regulating rod, shim 1, and shim 2 rod down limit switches with new limit switch system 11 /17 Replaced regulation rod magnet tape VI. Summary of 10 CFR 50.59 changes No 50.59 changes were made to the facility in CY 2017. One activity was screened for 50.59 applicability and it was evaluated not to require a full 50.59 evaluation or NRC approval.

VII. Radioactivity Releases A. Listed below are the total amounts of radioactive gaseous effluents released to the environment beyond the effective control of the reactor facility Table 1. Gaseous Effluents Released to the Environment in CY 2017 Month Argon-41 R-113 License Tritium -HTO 10CFR20 Allowable (mCi)

• Allowable (Ci) (Ci) (mCi)

January 0.5673 5.833 0.113 124 February 0.4289 5.833 0.009 124 March 0.7189 5.833 0.047 124 April 0.9772 5.833 0.085 124 May 0.8553 5.833 0.087 124 June 1.3981 5.833 0.065 124 July 1.2283 5.833 . 0.091 124 AUQUSt 0.2342 5.833 0.071 124 September 0.1493 5.833 0.041 124 October 0.1509 5.833 0.100 124 November 0.0411 5.833 0.000 124 December 0.0893 5.833 0.092 124 Total 6.8388 70.00 0.801 1488

% of Allowable 9.7697% ------------------- 0.054% -------------------

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• Note: The tritium concentrations are estimates based on the amount of water lost by evaporation from the reactor multiplied by the concentration of tritium as HTO.

Tritium sample analyses were performed by ALS Laboratories. '

B. No liquid releases were made during the 2017 calendar year.

C. During the year Na-24 and Br-82 were detected on CAM filter analyses.

Conservative estimated releases for these isotopes are in Table 2 .

Ta bl e 2 RI e eases ofN on-Gaseous soopes1n t . CY 2017 .

Isotope µCi µCi/ml 10 CFR 20 limit (uCi/ml)  % of limit Na-24 0.9679E-3 1.302E-14 7.00E-09 1.859E-4 Br-82 3.2314E-3 4.346E-14 5.00E-09 8.691E-4 VIII. Radiation Monitoring Our program to monitor and control radiation exposures included the four major elements below during the operating year.

1. Ten (10) gamma-sensitive area monitors, and one (1) neutron-sensitive area monitor, are located throughout the Nuclear Science Building. A remote readout panel is located in the reactor health physics office. High alarm set points range from 2 mR/hr to 50 mR/hr. High level alarms are very infrequent and due to sample movements. These monitors are calibration-checked annually.

2. One Continuous Air Monitor (CAM) samples air in the reactor bay. An equilibrium concentration of about 1.5 x 1o-8 µCi/ml present for two minutes will result in an increase of about 500 cpm above background. Two alarm setpoints are a low-level alarm set at 5,000 cpm and a high level alarm set at 10,000 cpm. Reactor bay air is sampled during all reactor operations. The fixed particulate air filter is normally changed each week and counted on a HPGE gamma spectrometer. The charcoal filter, positioned behind the particulate air filter, is also normally changed and counted weekly. Filter data showed radioisotope concentrations less than allowable airborne concentration limits given in 10 CFR Part 20, Appendix B, Table 2 for all particulate radioisotopes produced by the reactor.

3. Contamination wipe surveys and portable instrument radiation surveys are performed at least once a month. The portable instruments are calibrated with a 3-Curie (initial activity) Cs-137 source traceable to NBS, and wipes are counted on a Gamma Products G5000W low-level counting system. The highest removable contamination found was during the April surveys, at 37341 pCi/100 cm 2 beta-gamma, located in the reactor bay on the end of the westtable. Gamma spectroscopy revealed this contamination to be Tc-99m and Mo-99. The source of this contamination was very likely to be a threading lubricant for the CT rods, which contains molybdenum, which was activated by the neutron flux in the core. These rods are often unthreaded 4

from each other on this table. Subsequent decontamination returned the contamination activity levels to normal. Future manipulation of the CT rods were done after a sufficient decay period to allow this activated lubricant to decay. The next highest contamination was found during the June surveys, at 750 pCi/100 cm 2 beta-gamma, on the mobile lead shield near the ion exchange resin tank. This shield is seldom cleaned, so small amounts of residual contamination likely built up over time.

This area was subsequently decontaminated to levels below the removable contamination limit. No areas were greater than 9.3 pCi/100 cm 2 alpha contamination, which does not require decontamination as it is well below the limit of 90 pCi/100 cm 2 alpha.

The roof area over the reactor tank is roped off and posted as a radiation area (averaging 2.5 mR/hr) during 1 MW operations.

4. TLD dosimeters were used at seven outdoor environmental stations. Reactor facility visitors are issued self-reading electronic dosimeters. Reactor staff personnel are issued beta, gamma, albedo neutron badges.

Table 3. Personnel Monitoring Results (12/1/16 -11/30/17)

Whole Body (Rem) Whole Body (Rem)

Employee code Extremity (Rem)

Deep Dose Equiv. Shallow Dose Equiv.

E0888 0.341 0.390 0.590 E0707 0.536 0.691 0.809 E0908 0.179 0.213 0.472 E0715 0.132 0.154 0.133 Reactor visitors and visiting experimenters wore electronic pocket dosimeters which showed that no individual's reading greater than 13.0 mr in a single visit or as a cumulative annual dose.

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Table 4. Environmental Dose Results (Oct 2016 through Sept 2017)

Dose Dose Dose Dose Total Location Oct.- Dec. Jan-Mar Apr-June July-Sept.

(RAD) (RAD) (RAD) (RAD) (RAD)

Control (Background) 0.057 0.053 0.064 0.061 0.235 Main Exhaust 0.044 0.050 0.024 0.063 0.181 West Vehicle Gate 0.027 0.074 0.022 0.019 0.142 West Room 151 0.075 0.074 0.061 . 0.062 0.272 Gate Cooling Tower 0.014 0.000 0.000 0.000 0.014 SE Light Pole 0.000 0.000 0.000 0.000 0.000 SW Light Pole 0.000 0.000 0.000 0.000 0.000*

Rx Fence Loading 0.039 0.037 0.045 0.038 0.159 Dock Tunnel 0.028 0.023 0.017 0.022 0.090 Note: Above totals have the background subtracted (see control badge). All TLDs were supplied and analyzed by Mirion Technologies.

IX. Environmental Monitoring Very small releases of two non-gaseous isotopes were detected on the CAM filters during the year. These two isotopes (Na-24 and Br-82) were discharged through the normal air exhaust above the roof of the reactor bay. The amounts released are shown in Table 2.

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