ML20188A338

UC Davis Mcclellan Nuclear Research Center 2019 Annual Report

ML20188A338
Person / Time
Site:	University of California-Davis
Issue date:	07/06/2020
From:	Frey W McClellan Nuclear Research Center
To:	Linh Tran Office of Nuclear Reactor Regulation
References
Download: ML20188A338 (22)

Text

UNIVERSITY OF CALIFORNIA, DAVIS BERKELEY DAVIS

• IRVINE

• LOS ANGELES

• MERCED

• RIVERSIDE

• SAN DIEGO

• SAN FRANCISCO { ij _SANTA BARBARA __

• SANTA __

CRUZ McClellan Nuclear Research Center UNIVERSITY OF CALIFORNIA Davis (9 16)-614-6200 July 6th , 2020 Linh Tran US Nuclear Regulatory Commission 11555 Rockville Pike MS 12-D3 Rockville, MD 20852-2738

SUBJECT:

UC Davis McClellan Nuclear Research Center 2019 Annual Report Attached is the UC Davis McClellan Nuclear Research Center 2019 Annual Report for reactor operations. If you have any questions concerning the report, please feel free to contact me directly. To the best of my knowledge the data presented in the report is accurate and truthful.

I declare under penalty of perjury that the foregoing is true and correct.

Sincerely, 0/2 //1/,

Wesl~pf{y PhD Facility Director

2019 ANNUAL REPORT Docket Number 50-607 License Number R-130

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019

1. Introduction The University of California, Davis, McClellan Nuclear Research Center (MNRC) consists of a research reactor, associated radiography and positioning equipment, and a wide variety of equipment to support broad-based research activities. This MNRC Annual Report is published each year in support of the license provided by the United States Nuclear Regulatory Commission (NRC).

The aforementioned license is for the operation of a steady-state TRIGA' reactor with pulsing and square wave capability.

It is the primary intent of this document to provide information relevant to the safe operation of the UCD/MNRC. A brief description of the MNRC facility and administration is followed by operational events and health physics information concerning this facility during CY 2019.

2. UCD/MNRC Facility Description The UCD/MNRC is located on the McClellan Industrial Park site; the reactor is housed in Building 258. The McClellan Industrial Park site is approximately 2600 acres, located eight miles northeast of Sacramento, California.

The UCD/MNRC facility is a three level 14,720 sq. ft. rectangular-shaped enclosure that surrounds a 2 MW research reactor. The UCD/MNRC provides four neutron beams to four bays for radiography and other research and commercial activities. All four bays are capable of using radiography film techniques and electronic imaging devices. Space, shielding and environmental controls are provided by the enclosure for neutron radiography operations performed on a variety of samples. Adequate room has been provided to handle the components in a safe manner.

In addition to the radiography bays, the UCD/MNRC reactor also has several in-core facilities ranging from a pneumatic tube system to a central irradiation facility.

For more detailed information on the UCD/MNRC project, the reader is referred to the UCD/MNRC Safety Analysis Report.

3.0 UCD/MNRC Administration UCD/MNRC Organization. The UCD/MNRC is licensed by the Nuclear Regulatory commission (NRC) to operate under the provisions of operating license R-130.

The University of California Regents have designated the Chancellor at UC Davis to be the license holder. The UCD Chancellor has in-turn delegated the Vice Chancellor for Research to be the licensee of record.

The UCD/MNRC is under the direction of the UCD/MNRC Director.

1 UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 4.0 Facility Modifications (Section 50.59 of 10CFR Part 50), and experiments.

None 5.0 Approved Changes to Experiments None 6.0 Licensing and Regulatory Activities 6.1 NRC Items

a. The Nuclear Regulatory Commission conducted a semi-annual inspection the week of 28 January 2019. No findings reported.

b. The Nuclear Regulatory Commission conducted an inspection the week of 8 April 2019. No findings reported.

c. The Nuclear Regulatory Commission also visited the MNRC during the week of 8 April 2019 for the purpose of discussing issues related to facilities relicensing.

d. The Nuclear Regulatory Commission conducted an inspection the week of 12 August 2019. No findings reported.

6.2 Nuclear Safety Committee (UCD/NSC)

a. The Nuclear Safety Committee held its semi-annual meetings on 21 February and 29 August 2019.

b. The Nuclear Safety Committee performed an Operations audit for 2019 on 29 August 2019.

c. The Nuclear Safety Committee performed an audit of the Radiation Safety Program on 14 November 2019.

d. The Nuclear Safety Committee performed a Security audit on 12 December 2019.

7.0 OPERATIONS OPERATING HISTORY:

TOTAL OPERATING HOURS THIS YEAR: 1522.49 TOTAL OPERATING HOURS: 54548.26 TOTAL MEGAWATT HOURS THIS YEAR: 1435.06 TOTAL MEGAWATT HOURS: 68934.71 TOTAL NUMBER OF PULSES PERFORMED THIS YEAR: 0 TOTAL NUMBER OF PULSES PERFORMED: 484 2

UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 7.1 UNSCHEDULED REACTOR SHUTDOWNS and NOTED PROBLEM AREAS:

In 2019, there were two (2) unscheduled reactor shutdowns at the MNRC reactor facility. The following is a list of the unscheduled shutdowns:

2019 UNSCHEDULED REACTOR SHUTDOWNS Type of Failures Total Number CSC 0 Other 2 TOTAL NUMBER OF UNSCHEDULED SHUTDOWNS IN 2019 2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec CSC 0 0 0 0 0 0 0 0 0 0 0 0 Other 0 1 0 0 0 0 0 0 1 0 0 0 I Notes I I 1 I I I I I I I 2 I I I I Notes:

1: Object dropped in the Rx Tank during facility tour 2: Inadvertent Operation of the Rx Room Manual Scram Button January

1. There were no unscheduled shutdowns in the month of January.

2. There were no callbacks to the facility in January.

February

1. There was one unscheduled shutdown in the month of February.

a. During a tour of the Facility, an item was dropped into the reactor Tank. The Reactor was shutdown to recover the item. See the Anomaly Report.

2. There were no callbacks to the facility in February.

March

1. There were no unscheduled shutdowns in the month of March.

2. There were no callbacks to the facility in March.

April

1. There were no unscheduled shutdowns in the month of April.

2. There were no callbacks to the facility in the month of April.

May

1. There were no unscheduled shutdowns in the month of May.

2. There were no callbacks to the facility in the month of May.

3 UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 June

1. There were no unscheduled shutdowns in the month of June.

2. There was one callback to the facility in the month of June.

a. Security Transmit Fail.

July

1. There were no unscheduled shutdowns in July.

2. There were no callbacks to the facility in the month of July.

August

1. There were no unscheduled shutdowns in the month of August.

2. There no callbacks to the facility in the month of August.

September

1. There was one unscheduled shutdown in the month of September.

a. The Reactor was scrammed due to the inadvertent operation of the Reactor Room Manual Scram Button. Operator Error.

2. There were no callbacks to the facility in the month of September.

October

1. There were no unscheduled shutdowns in the month of October.

2. There was one callback to the facility in the month of September.

a. Scram Database Timeout. Cleared on Acknowledgement.

November

1. There were no unscheduled shutdowns in the month of November.

2. There were no callbacks to the facility in the month of November.

December

1. There were no unscheduled shutdowns in December.

2. There was one callback to the facility in the month of December.

a. Scram Database Timeout. Cleared on Acknowledgement 4

UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019

7.2 ANOMALIES

During 2019, there was one anomaly at the MNRC facility and no Radiological Incident Investigations.

Anomaly Report Date: 7 February, 2019 Time: 1308 hrs Describe the reactor conditions prior to the anomaly and what occurred during the anomaly:

The reactor was operating normally at 1 MW supporting radiography operations in Bays 1 and 2, and for a facility tours by a large group of High School Science students.

At 1308 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.97694e-4 months <br /> it was noted by the tour guide in the Reactor Room that a couple of the students were acting a little strangely and upon inquiring what was the issue, they indicated to the tour guide that they might have dropped a fit bit watch into the reactor tank.

The tour guide notified the Reactor Operator in the control room, the reactor was shut down.

What actions were taken to correct the anomaly:

The facility tours were immediately stopped and all visitors were escorted from the facility.

After the reactor was shutdown, primary and demineralizer pumps were secured.

Facility staff performed a visual inspection of the reactor tank from the top of the tank and could not find the dropped object.

The underwater camera was set up and the object was located on the tank bottom under the Bay 1 insert to tank wall flange.

Using the aluminum pole and underwater camera assembly, the object was moved from under the flange to a more accessible location for recovery.

The object was recovered from the tank bottom utilizing a tape ball on the bottom of the underwater camera pole.

What corrective actions are needed to prevent this anomaly from recurring in the future:

As part of the pre-tour briefing, additional emphasis will be placed on reminding tour participants to remove all objects that could inadvertently detach from a person and fall into the reactor tank.

5 UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 7.3 MAINTENANCE OTHER THAN PREVENTIVE:

February System # Description Work Performed 5490 Helium Supply Replace expended Helium Supply bottle March System # Description Work Performed 1800 Reactor Ventilation DOP test Reactor Room Exhaust HEPA filters 1803 Rad-Vac DOP test Radiological Vacuum Cleaner 5490 Helium Supply Replace expended Helium Supply bottle 5330 DAC Computer Replaced Hard Drive April System # Description Work Performed 5490 Helium Supply Replace expended Helium Supply bottle May System # Description Work Performed 5490 Helium Supply Replaced expended helium supply bottle June System # Description Work Performed 5640 HV-2 Replaced failed HV-2 Blower Motor July System # Description Work Performed Replaced failed Reactor Ventilation Recirc Damper 5620 Reactor Ventilation Actuator 6

UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 August

1. MNRC completed the annual reactor maintenance shutdown during the month of August.

Technical Specification required periodic maintenance as well as general maintenance was performed.

2. Parametric values noted during testing are as follows:

Control Rod Worth:

Transient Rod: $1.90 Shim 1: $2.57 Shim 2: $2.48 Shim 3: $2.71 Shim 4: $2.92 Regulating Rod: $2.70 Control Rod Scram Drop Times:

Transient Rod: 0.34 sec Shim 1: 0.40 sec Shim 2: 0.37 sec Shim 3: 0.43 sec Shim 4: 0.38 sec Regulating Rod: 0.40 sec Shutdown Margin: $6.35 The normal nuclear instrument calorimetric calibration was performed. Both the NPP channel and the NM-1000 channels of the Nuclear Instruments were satisfactory, and no adjustments were required.

At Power Scram values: NPP-1000: 106% indicated, NM-1000: 104% indicated.

System # Description Work Performed Replaced Trimpot R102 for Mode 4 in the 5330 NM-1000 Campbelling module.

5490 Helium Supply Replaced expended helium supply bottle September System # Description Work Performed 5490 Helium Supply Replaced expended helium supply bottle November System # Description Work Performed 1001 Reactor CAM Replaced failed Crimp connector 5330 NM-1000 Adjusted R102 for Mode 4.

5490 Helium Supply Replaced expended helium supply bottle 7

UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 7.4 Training January

1. Senior Reactor Operators completed training on Facility Design and Operating Characteristics.

2. One person (trainee) completed training of Spill procedures and on donning and removal of Anti-Cs.

3. Hosted and conducted training for a UC Davis Physics Class (Classroom and Practical Lab training).

4. Hosted and conducted training for Public Safety Academy Classes (Classroom and Practical Lab training).

February

1. Three Senior Reactor Operators completed training on Instrumentation and Control.

2. Hosted and conducted training for Franklin High School students (Classroom and Practical Lab training).

3. Hosted and conducted training for Maidu Virtual Charter Academy (Classroom and Practical Lab training).

March

1. One Senior Reactor Operators completed training on several modules on Design and Operating Characteristics.

2. One Senior Reactor Operators completed training on Instrumentation and Control.

April

1. Facility personnel completed Annual ALARA and annual Safety/Security training.

2. Hosted and conducted training for members of the California Highway Patrol.

3. Hosted and conducted training for a UC Berkeley NE Class (Classroom and Practical Lab training).

4. Hosted and conducted training for a UC Merced Class (Classroom and Practical Lab training).

5. Hosted and conducted training for a Tracy High School Class (Classroom and Practical Lab training).

May

1. Hosted and conducted training for a UC Davis Class (Classroom and Practical Lab training).

2. Conducted training and tours foe EAOP Classes.

June

1. Two Senior Reactor Operators completed Radiation Safety for Operators Training.

2. Hosted and conducted training for a California Aerospace Summer School Program Class (Classroom and Practical Lab training).

3. Hosted and conducted training for a Mesa High School (Classroom and Practical Lab training).

4. Hosted and conducted training for a UCD Physics Class (Classroom and Practical Lab training).

5. Conducted training and tours for Continuing Education Classes 8

UCD/MNRC Annual Report 2019

vis MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 July

1. Two Senior Reactor Operators completed Radiation Safety for Operators Training.

2. MNRC conducted summer school classes for the SMASH group.

3. MNRC conducted summer school classes for the University COSMOS program.

4. 3 Facility personnel completed Neutron Radiography specific training.

August

1. All Senior Reactor Operators and one trainee completed Fuel and Fuel Handling training.

2. Hosted and conducted training for a UCD NAA Class (Classroom and Practical Lab training).

September

1. Two Senior Reactor Operators completed Technical Specifications training.

October

1. Two Senior Reactor Operators completed Technical Specification training.

2. One Senior Reactor Operator completed Nuclear Theory training.

3. All Senior Reactor Operators completed the Annual Operators Examination.

4. Hosted and conducted training for a Douglass Middle School (Classroom and Practical Lab training).

November

1. One Senior Reactor Operator completed Normal, Abnormal, and Emergency procedures training.

2. Two Senior Reactor Operators completed Nuclear Theory training.

December

1. Three Senior Reactor Operators completed training on Normal, Abnormal and Emergency Procedures.

2. One Senior Reactor Operator completed Nuclear Theory training.

2. Three Senior Reactor Operators completed their Biennial Medical Exams.

9 UCD/MNRC Annual Report 2019

J s MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 C] Operating Hours 4500 4000 3500 3000 - ~ ~

2500 ~ - - ~ ~

2000 ~ ~ ~ - - ~ ~

1500 - -

I- 1-1 I I I I

~ ~ ~ ~ ~

1000 ~ ~ ~ - -

~I- - ~ ~ - - ~ ~ -

• I I I I I I I I 500 ~ ~ ~ - - ~ - - ~ ~ - - ~ ~ - ~ ~ - - ~ ~ - ~ ~ -

0 I I I I I I I I I I I I I I I I I I I I 10

J s MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 Unscheduled Reactor Shutdowns 2019 5

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec CSC 0 0 0 0 0 0 0 0 0 0 0 0 Other 0 1 0 0 0 0 0 0 1 0 0 0 2019 Total 0 1 1 1 1 1 1 1 2 2 2 2 2018 Total 0 0 0 1 1 1 2 2 2 2 3 3 Months 11

J s MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 Reactor Reactor Hours Hours (2019)

(2019)

Reactor Hours 2019 180 160 140 Monthly Operating and Megawatt Hours 120 100 80 60 40 20 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2018 Op-Hrs 121.365 98.3 94.03 113.55 127.32 111.88 96.7 111.8 101.17 161.93 132.95 87.89 2018 Mw-Hrs 115.09 93.5 91.41 108.98 112.49 98 87.46 93.71 94.71 156.98 127.26 81.89 2019 Op-Hrs 136.35 107.13 98.09 148.2 139.93 95.73 91.35 136.62 145.18 171.39 134.22 113.1 2019 Mw-Hrs 129.6 103.14 90.88 141.55 129.14 92.27 88.86 109.48 138.19 166.47 131.01 105.47 12

J s MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 Reactor Tank Irradiation Facilities 2019 34 33 32 31 30 29 28 27 Number of Irradiations 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8 7

6 5

4 3

2 1

0 Jan Feb --

Mar 1---a Apr

- -- May Jun Jul Aug Sep

- IH Oct -

Nov -

Dec -

Pneumatic 0 0 0 2 1 0 32 4 0 6 0 0 Silicon Fixture 0 1 1 0 1 0 0 2 0 0 1 1 Central Facility 0 0 1 0 1 0 1 1 0 2 0 1 Argon 0 0 0 0 0 0 0 0 0 0 0 0 Neutron Irradiator 3 0 2 3 1 0 0 1 2 0 0 1 Months 13

J s MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 Bay Utilization (Shutter Operations) 2019 500 450 400 Number of Irradiations 350 300 250 200 150 100 50 0

n _o_

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Bay 1 147 172 189 194 199 145 146 245 281 418 364 318 Bay 2 221 108 173 186 136 108 115 117 197 438 388 208 Bay 3 0 5 0 0 0 1 0 0 0 0 1 0 Bay 4 0 1 0 3 17 0 0 0 3 0 0 16 Months 14

J s MNRC$ UCD/MNRC ANNUAL REPORT FOR 2019 Bay Irradiation Requests Completed 2019 275 250 +-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --- I -- - - - - - - - - - - - - - - - - I 225 200 175 Number of Irradiation Requests 150 125 100 75 50 25 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec a Bay 1 114 109 102 118 137 103 92 106 132 254 189 192

• a Bay 2 Bay 3 120 0

59 0

128 1

121 0

46 1

64 0

100 0

33 0

75 0

154 0

89 0

75 0

a Bay 4 1 0 0 0 0 1 1 0 0 0 0 1 Months 15

MNRC$

McCLELLAN NUCLEAR RESEARCH CENTER UCD/MNRC ANNUAL REPORT FOR 2019 8.0 Radioactive Effluents A summary of the nature and amount of radioactive effluents released or discharged to the environment beyond the effective control of the MNRC, as measured at or prior to the point of such release or discharge, include the following:

8.1 Liquid Effluents No liquid effluents were released during 2019.

8.2 Airborne Effluents Airborne radioactivity discharged during 2019 is tabulated in Table 1 below.

TABLE 1 2019

SUMMARY

OF AIRBORNE EFFLUENTS MONTH TOTAL EST.MAX AVG. FRACTION OF EST. DOSE (2) FRACTION OF TOT. EST. AVERAGE EST. CONC. OF APPLICABLE FROM Ar-41 APPLICABLE QUANTITY CONC. OF QUAN. Ar-41 IN 10CFR20 Ar-41 FOR 10CFR20 OF ACT. PART. ACT.

Ar-41 UNRESTRICTED CONC. LIMIT FOR UNRESTRICTED DOSE IN RELEASED RELEASED AREA (1)(3) UNRESTRICTED AREA (1) CONSTRAINT PART. WITH AREA (1) FOR FORM HALF-LIFE UNRESTRICTED WITH > 8 DAYS AREA (1)(4) HALF-LIFE

>8 DAYS (Ci) (uCi/ml) (%) (mrem) (%) (Ci) (uCi/ml)

JAN 2.57 1.50E-10 1.5% 0.91 9.13% NONE NONE FEB 1.73 1.02E-10 1.0% 0.62 6.19% NONE NONE MAR 2.54 1.49E-10 1.5% 0.91 9.06% NONE NONE APR 2.63 1.54E-10 1.5% 0.94 9.40% NONE NONE MAY 1.56 9.05E-11 0.9% 0.55 5.51% NONE NONE JUN 1.32 7.67E-11 0.8% 0.47 4.67% NONE NONE JUL 1.72 9.99E-11 1.0% 0.61 6.08% NONE NONE AUG 1.62 9.40E-11 0.9% 0.57 5.72% NONE NONE SEP 1.97 1.14E-10 1.1% 0.70 6.96% NONE NONE OCT 3.21 1.87E-10 1.9% 1.14 11.37% NONE NONE NOV 4.85 2.82E-10 2.8% 1.71 17.14% NONE NONE DEC 1.87 1.09E-10 1.1% 0.66 6.62% NONE NONE TOT 27.58 NONE NONE AVG 2.30 1.34 E-10 1.3% 0.82 8.15%

(1) This location is 240 meters downwind which is the point of maximum expected concentration based on the worst case atmospheric conditions (see MNRC SAR Chapter 11).

(2) Based on continuous occupancy and the calculation techniques used in Appendix A of the MNRC SAR (Ar-41 at 2.3E-10 uCi/ml continuous for one year equals 1.4 mrem).

(3) 10CFR20 Limit for concentration is 1E-8 (Appendix B, Table 2);

(4) Constraint for dose is 10 mrem/year [10CFR20.1101(d)]

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MNRC$

McCLELLAN NUCLEAR RESEARCH CENTER UCD/MNRC ANNUAL REPORT FOR 2019 8.3 Solid Waste No solid radioactive waste was shipped this year.

9.0 Radiation Exposure Radiation exposure received by facility operations personnel, facility users, and visitors during 2019 is summarized in Table 2 below.

TABLE 2 2019

SUMMARY

OF PERSONNEL RADIATION EXPOSURES NUMBER OF AVERAGE GREATEST AVERAGE GREATEST INDIVIDUALS TEDE INDIVIDUAL EXTREMITY EXTREMITY PER TEDE (1)

INDIVIDUAL (mrem) (mrem) (mrem)

(mrem)

FACILITY 7 46 107 76 380 PERSONNEL FACILITY 45 <1.0 1.0 *

• USERS VISITORS 1007 <1.0 2 * *

(1) Only 3 individuals received extremity exposure

• Extremity monitoring was not required.

17

MNRC$

McCLELLAN NUCLEAR RESEARCH CENTER UCD/MNRC ANNUAL REPORT FOR 2019 10.0 Radiation Levels and Levels of Contamination Radiation levels and levels of contamination observed during routine surveys performed at the MNRC during 2019 are summarized in Table 3 below.

TABLE 3 2019

SUMMARY

OF RADIATION LEVELS AND CONTAMINATION LEVELS DURING ROUTINE SURVEYS AVERAGE HIGHEST AVERAGE HIGHEST (mrem/hr) (mrem/hr) (dpm/100cm2) (dpm/100cm2)

OFFICE SPACES <0.1 <0.1 <5000(1) <5000(1)

REACTOR CONTROL RM <0.1 <0.1 <5000(1) <5000(1)

RADIOGRAPHY CONTROL RM <0.1 <0.1 <5000(1) <5000(1)

COUNTING LAB <0.1 <0.1 <5000(1) <5000(1)

STAGING AREA <0.1 25 <5000(1) <5000(1)

FACILITY (I/S Fence) <0.1 <0.1 <5000(1) <5000(1)

EQUIPMENT RM 0.6 (4) 134 (5) <800(2) <800(2)

DEMINERALIZER AREA 11(4) 300(5) <800(2) <800(2)

REACTOR RM 3.2(4) 560(5) <800(2) <800(2)

RADIOGRAPHY BAYS 0.5(3) 290(5) <800(2) <800(2)

(1) <5000 dpm/100 cm2 = Less than the lower limit of detection for a scanning survey.

(2) <800 dpm/100 cm2 = Less than the lower limit of detection for a swipe survey.

(3) Due to Bay 1 Storage Areas; all other areas and bays are significantly lower (typically <0.1 mrem/hr).

(4) General area dose rate.

(5) Maximum contact dose rate.

18

MNRC$

McCLELLAN NUCLEAR RESEARCH CENTER UCD/MNRC ANNUAL REPORT FOR 2019 11.0 Environmental Surveys Environmental surveys performed outside of the MNRC during 2019 are summarized in Tables 4

& 5 below. The environmental survey program is described in the MNRC Facility Safety Analysis Report.

TABLE 4 2019

SUMMARY

OF ENVIRONMENTAL TLD RESULTS (WITH NATURAL BACKGROUND(1) SUBTRACTED)

AVERAGE HIGHEST (mrem) (mrem)

ON BASE (OFF SITE 1-20 & 64) 5 9 ON SITE (SITES 50 - 61 & 65-71) 17 29 (1) Natural background assumed to be the off base (Sites 27-42) average of 29 mrem.

19

MNRC$

McCLELLAN NUCLEAR RESEARCH CENTER UCD/MNRC ANNUAL REPORT FOR 2019 TABLE 5 2019

SUMMARY

OF RADIOACTIVITY IN WELL WATER ALPHA BETA TRITIUM Cs-137 (pCi/l) (pCi/l) (pCi/l) (pCi/l)

AVERAGE <MDA 1.91 <MDA <MDA HIGHEST <MDA 2.40 <MDA <MDA MDA is the minimum detectable activity at the 95% confidence level.

The MDA range for the analyzed radionuclides (pCi/L).

MIN MAX Alpha 1.38 2.63 Beta 1.42 1.92 Tritium 219 275 Cs-137 1.54 1.87 20