ML21123A168
| ML21123A168 | |
| Person / Time | |
|---|---|
| Site: | National Bureau of Standards Reactor |
| Issue date: | 04/12/2021 |
| From: | Dimeo R US Dept of Commerce, National Institute of Standards & Technology (NIST) |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML21123A168 (9) | |
Text
UNITED STATES DEPARTMENT OF COMMERCE National Institute of Btanclerda and Technology Gaithersburg, Maryland 20888-VOICE (301) 975-6210 FAX (301) 975-9427 April 12, 2021 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
Subject:
Docket #50-184 Gentlemen and Ladies:
Transmitted herewith is Operations Report No. 73 for the NBSR. The report covers the period January 1, 2020 to December 31, 2020.
Sincerely, Robert Dimeo Director, NIST Center for Neutron Research Enclosure cc: Kevin Roche U.S. Nuclear Regulatory Commission 11555 Rockville Pike, M/S O-12-D20 Rockville, MD 20852-2738 U.S. Nuclear Regulatory Commission ATTN: Paulette Torres One White Flint North 11555 Rockville Pike, M/S O-12-D20 Rockville, MD 20852-2738 NISI
NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY REACTOR (NBSR)
Docket #50-184 Facility License No. TR-5 Operations Report
-- #73-January 1, 2020 - December 31, 2020 This report contains a summary of activities connected with the operations of the NBSR. This report fulfills the requirements of section 6.7.1 of the NBSR Technical Specifications for the period from January 1, 2020 to December 31, 2020.
The section numbers in the report (such as 6.7.1 (1)) correspond to the sections in the Technical Specifications.
April 12, 2021, Robert Dimeo Director, NIST Center for Neutron Research
TABLE OF CONTENTS 6.7.1(1) Summary of plant operations including the energy produced by the reactor and the hours the reactor was critical 6.7.1(2) Unscheduled shutdowns, including reasons therefore 6.7.1(3) Tabulation of major preventative and corrective maintenance operations having safety signrficance
, 6.7.1(4) A brief description, including a summary of the safety evaluations, of changes in the facility or in procedures a1;1d of test and experiments carried out pursuant to 10 CFR 50.59 6.7.1(5) Summary of the nature and amount of radioactive effluents released or discharged to the environs and the sewer beyond the effective control of the licensee as measured at or prior to the point of such rel_ease or discharge 6.7.1(6) Summary of environmental surveys performed outside the facility 6.7.1 (7) Summary of significant exposures received by facility personnel and visitors 2020 Operations Report for NBSR (TR-5)
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6.7.1(1) Summary of plant operations including the energy produced by the reactor and the hours the reactor was critical During the period January 1, 2020 through December 31, 2020 the reactor was critical for 3,669.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> with a thermal energy output of 72,451.10 MWH (150.9 equivalent full power days). Major activities during this period included:
o Performed Operator Requalification Training and Exam for licerJsed operators.
o Completed ECN-1148 Reg Rod drive replacement.
,o Switched power supply for DVW-95A, 95B, 100A, and 100B air solenoids from DC to AC o Replaced all activated charcoal in the emergency ventilation lfilters. 42 filters /
2200 pounds of charcoal o Extended shutdown due to the COVID-19 pandemic.
6.7.1(2) Unscheduled shutdowns, including reasons therefore There were twelve unplanned shutdowns as of December 31, 2020:
- 1. The reactor was manually shutdown on 03/17/2020 when a possible COVID 19 exposure occurred. The Reactor was not restarted for routine operations until 07/15/2020. The completion of Cycle #651 occurred on 08/09/2020.
- 2. At 1646 on 09/03/2020 the reactor was manually sh.utdown when a commercial power failure caused the loss of 2 Main Se~ondary pumps and subsequent fault codes on the associated VFD's. The VFD's were reset and the Main Secondary pumps were restarted. Reactor was restarted and reached 19.5 Mw at 1748.
- 3. At 1325 on 10/2/2020 a failed air solenoid on DWV-95B resulted in an unplanned reactor shutdown due to a low flow scram. The reactor was returned to 20MW at 0846 on 10/4/2020. There was a decision to extend the cycle to 1600 on 10/12/20 to minimize the loss of operational time.
- 4. At 0725 on 11/15/2020 there was a reactor major scram due to a spike on RM 3-5 (Normal air). No readily apparent cause of spike. Restarted reactor and returned to 20 MW at 0901.
2020 Operations Report for. NBSR (TR-5)
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- 5. At 1735 on 11/20/2020 there was a reactor scram due to Outlet flow low (it appears that D\IVV-95B cycled shutthen open over approx.15 seconds)
Restarted Reactor to 20 Mw@ 1757.
- 6. At 1829 on 11/24/2020 there was a reactor scram due to Outlet flow low (it appears that D\IVV-95B cycled shut then open) Restarted Reactor to 20 Mw @
1909.
- 7. At 1845 on 11/25/2020 there was reactor scram due to Outlet flow low (it appears that D\IVV-95B cycled shut then open) Restarted Reactor to 20 Mw @ 1905.
- 8. At 1101 on 11/29/2020 there was a reactor scram due to Outlet flow low (it appears that D\IVV-95B cycled shut then open) Restarted Reactor to 20 Mw @
1118. ~
- 9. At 0747 on 11/30/2020 there was a reactor scram due to Outlet flow low (it appears that DWV-95B cycled shut then open) Restarted Reactor to 20 Mw @
0814.
10.At 1817 on 12/1/2020 there was a reactor scram due to Outlet flow low (it appears that DWV-95B cycled shut then ope.n) Restarted Reactor to 20 Mw @
0833.
11 . At 1600 on 12/2/2020 there was a reactor shutdown to repair of all HX LOCA solenoid valves. Reactor restarted and returned to 20MW@ 0924. Cycle extended until 2350 12/20/20. This action was planned due to items 3, 5-10 above.
- 12. At 0337 on 12/14/?020 the reactor was shut down in response to increasing ventilation radiation levels caused by the Process Room supply fan (SF-11) tripping off. The Reactor was not restarted until 12/16/2020. Cycle continued until 2350 12/20/2020 6.7.1(3) Tabulation of major preventative and corrective maintenance operations having safety significance Note: Some of these items may be also listed as Engineering Change Notices (ECN) in section 6.7.1 (4).
The following list is significant I &C maintenance and repair tasks:
(_
32* regularly scheduled calibrations 2020 Operations Report for NBSR (TR-5)
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o Performed inspection of all shim am, clutch gaps. No changes in clutch gaps since last check o Replaced RM 3-3 HV Power Supply o Fixed #3 shim console indication problem. Replaced the RVDT.
o Completed ECN-1148 reg rod drive replacement.
o Found relay PSX for PC-151 for EF-5 and EF-6 failed. Replaced relay.
o ECN 1178 was perfom,ed on DWV-95A, 95B, 100A, and 100B.
o' Replaced #1 C.T. fan controller per ECN 1163.
o Installed shielding around RM3-5 to prevent electrical interference.
The follow may contain duplications in other sections of this report, but this listing is work accomplished during the designated scheduled reactor maintenance shutdowns.
February - March 2020 Shutdown o Performed Operator Requalification Training and Exam for licensed operators.
o Changed PW-9 diaphragm and inspec:ted seals o Troubleshot DV\N-10 and DVW-37 leak detection system.
o Installed Cooling Tower Roll Up Door Proximity Sensors and Refurbished
/chain Guides.
o Replaced C100 Truck Door trolley wheels.
o Replaced CT Fan #4 and #5 Starters o Checked and verified clutch gap on #1 and #2 Shim Arm Drives o Gre?sed the motor bearings and change out the pedestal oil on #2 and #3 Main D20 pumps June 2020 Shutdown o Perfom,ed numerous Technical Specification procedures and Instrument calibrations to facilitate the restarting the NBSR o Performed inspection of #3 and #4 shim am, clutch gaps. No changes in clutch gaps since last check o Fixed #3 shim console indication problem. Replaced the RVDT o Started_reactor to allow for ,Cold Source Testing o Replaced #2 Cooling Tower Fan Motor August - September 2020 Shutdown 2020 Operations Report for NBSR (TR-5) 1
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o Performed visual inspection of the Fuel Transfer Valves to verify construction for possible replacerrient o Repaired the storage pool cover.
o ' Replaced all activated charcoal in the emergency ventilation filters. 42 filters/
2200 pounds of charcoal o Replaced C-100 panel Boa-rds PF and RF. .
o Removed old cold source piping that penetrated the confin~ment building. All penetrations tested satisfactory.
October - November 2020 Shutdown o Installed New Reg Rod Drive System o Greased the motor bearings and change out the pedestal oil on #1 and #4
¥ain D20 pumps o Change Storage Po*oI IX Pre and After Filters.
o c*heck D.C. Brushes on EF-5, EF-6 and D2O Shutdown Pump Motors.
o Install Camera in Process Room.
o Replace C100 Panelboards E, NOP, RG (Effects significant portions of the 8-wing and Confinement building receptacles, lighting and UPS receptacles).
o Replaced "A" and "B" diesel batteries.
December 2020 Shutdown o Repaired C100 Concrete Floor.
o Secondary Pump VFD Maintenance.
o Greased the motor bearings and change out the pedestal oil on #2 and #3 Main D20 pumps o Replaced H-5 pickup tool with repaired original.
6.7.1(4) A brief description, including a summary of the safety evaluations, ,of changes in the facility or in procedµres and of test and experiments carried out pursuant to 10 CFR 50.59 There were four Level II Engineering Change Notifications (ECN) for which further evaluation was performed using 10 CFR 50.59. .
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ECN System or Component Description 1105 Confinement Confinement Leak Rate System Upgrade 1130 Electrical Supply Replacement of Confinement Building Panel Panelboards and CT Cell #4 & #5 Electrical Panels 1154 Confinement Confinement portion of-the 3.5 Kw refrigerator decommissioning 1178 I IC System HX LOCA Valve Solenoid Replacement & Change of Power Source 6.7.1(5) Summary of the nature and amount of radioactive effluents released or discharged to the *environs and the sewer beyond the effe,ctive control of the licensee as measured at or prior to the point of such release or discharge Gaseous releases in 2020 to the environs consisted of: 767 Curies of Ar-41, 1,079 Curies of H-3, and 0.00145 Curies of other beta-gamma emitters. The computer code EPA COMPLY version 1.7.1 was used to assess dose from these airborne releases.
Result from the COMPLY code showed that these releases complied with 10 CFR 20.1101 (d).
The table below summarizes the Building 2~5 disposal of licensed material into sanitary sewerage of 123,274 gallons of water, in 43 releases, for calendar year 2020.
H-3( 1l (STDEV[2s%])(4l C-14( 1l (STDEV[2s%]) Beta( 1, 2l (STDEV[2u]) Gamma(3l (STDEV[2u])
0.890 Ci (0.002 Ci) 1631 µCi (50 µCi) 46 µCi (6 µCi) 13.8 µCi (0.7 µCi)
I (1) Via Liquid Scintillation Spectroscopy (TRI-CARS), of routine/supervisory reviewed releases, along with the estimated secondary blowdown to sanitary sewer.
{2) Via Tennelec instrument (Series 5); includes contributions from gamma radionuclides.
{3) Gamma isotopes were identified using sample s having from -698 to ~1000 ml, in Marinelli beakers The following gamma emitters were indicated, in approximate decreasing order of importance: Cs-137, Co-60, Na-24, Tc-99M/Mo-99, Mn-56, Cr-51, Cd-115, Sb-122, La-1 40, Sb-124, 1-131 2020 Operations Report for NBSR (TR-5)
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(4) STDEV refers the average propagated standard deviation using an Excelfunction. For Alpha and Beta activity, 2 a is two times the standard sigma function. For H-3 and C-14, 2s% refers to an industry standard function defined by Packard / Perkin Elmer 2s% is the percent uncertainty in a gross count value (with 95% confidence limits), or 2s% = {100 X 2 X a)/ (Total Counts).
(5) For 2020 the a activity detected via Tennelec was 7 µCi (with STDEV [2 a] = 2 µCi) and is historically attributed to natural background.
All NCNR liquid radioactive effluerit relea$es complied with 10-CFR-20.2003 6.7.1(6) Summaries of environmental surveys performed outsJde the fa~ility Environmental samples of the water, grass, and/or soil showed no licensed radioactive material. Results from thermo-luminescent dosimeters located at the NIST fence line showed no statistically signmcant 1dose above background levels.
6.7.1(7) Summaries of significant exppsures received by facility personnel and visitors
- Dosimetry results:
1 For the 2020 Galendar year there were no doses above regulatory limits as stated in 10
,CFR 20.1201 and 20.1301 to members of the public or to occupational workers. This is based on dosimetry monitoring of personnel and surveys conducted inside and outside the facility. It should be noted that dosimetry results for occupational workers for the 4th quarter of 2020 are still pending at the time of this report as a result of the COVID-19 epidemic. However, all occupational workers at the NCNR are also monitored with electronic dosimeters or personal ion chambers and based on these measurements all 4th quarter results are below occupational limits.
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