ML12090A476

North Carolina State University Pulstar Reactor Annual Report for 2011

ML12090A476
Person / Time
Site:	North Carolina State University
Issue date:	03/29/2012
From:	Hawari A North Carolina State University
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML12090A476 (39)

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North Carolina State University is a land- Nuclear Reactor Program Grant university and a constituent institution Of The University of North Carolina The Universitv of North Carolina oWV1TWVM9- An Equal Opportunity/Affirmative Action Employer Nuclear Reactor Program Campus Box 7909 Raleigh, North Carolina 27695 http:/Awww.ne.ncsu.edu/nro/index.htmi Director 919.515.4598 Office 919.515.7294 (Fax) 919.513.1276 Shipping Address:

NC State University 2500 Stinson Dr.

Raleigh, NC 27695 29 March 2012 Attn: Document Control Desk US Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852 Re: Annual Report for 2011 License No. R-120 Docket No. 50-297 In accordance with Technical Specification 6.7.4, the annual operating report for our facility is attached.

If you have any questions regarding this correspondence or require additional information, please contact Gerald Wicks at 919-515-4601 or wicksgncsu.edu.

I declare under penalty of perjury that the forgoing is true and correct. Executed on 29 March 2012.

Ayman I. Hawari, Ph. D.,

Director, Nuclear Reactor Program North Carolina State University

Enclosures:

Annual Operating Report for 2011 Attachment A: PULSTAR Reactor Environmental Radiation Surveillance Report

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NORTH CAROLINA STATE UNIVERSITY DEPARTMENT OF NUCLEAR ENGINEERING PULSTAR REACTOR ANNUAL REPORT DOCKET NUMBER 50-297 For the Period: 01 January 2011 - 31 December 2011 The following report is submitted in accordance with Section 6.7.4 of the North Carolina State University PULSTAR Reactor Technical Specifications:

6.7.4.a Brief Summary:

Reactor operations have been routine during this reporting period with one exception. In July 2011 an unaccounted loss of approximately 3600 gallons of primary water occurred over a period of 14 days. Information on this abnormality is provided in "Results of Surveillance, Tests, and Inspections" below.

i Operating experience including a summary of experiments performed.

Reactor operations have been routine during this reporting period. The following is a brief summary of the types of experiments performed:

Teaching Laboratories, Short Courses, and Research

• Core thermal power measurements

• Dynamic reactivity measurements

• Axial power and peaking factor measurements (flux mapping)

• Reactor power determination using photodiode arrays

• Neutron fluence and spectral measurements

• In-core detector certification

• Accelerated lifetime testing for nuclear detectors

• Neutron radiography

• Positron production facility

• Neutron Diffraction Neutron Activation Analysis

• Crude oil

• Food samples

• Fish tissues

• Laboratory animal tissue

• Human hair, nails, and urine

• Polymers and plastics 1

0

• Sediment/soil/rocks

• Silicon crystals

• Textiles

• Water 718 Nuclear Services Neutron Reactor Utilization - 2011 Activation Analysis 719 Nuclear Services 5% Isotope Production 1%

Figure 1 - Reactor Utilization by Protocol ii Changes in Performance Characteristics Related to Reactor Safety:

None iii Results of Surveillance, Tests, and Inspections:

The reactor surveillance program has revealed no significant or unexpected trends in reactor systems performance during this reporting period. The Reactor Safety and Audit Committee (RSAC) performed its annual audit for the facility and determined that all phases of operation and supporting documents were in compliance.

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From 1 July 2011 to 14 July 2011 an unaccounted loss of approximately 3600 gallons of primary water occurred. The water loss stopped following the detection and repair of a leak site in the reactor pool liner. No primary water was found either inside or outside of the reactor facility. It was assumed the water was leaking into the ground surrounding the reactor site. The radioactivity present in the reactor water met regulatory limits for release to unrestricted areas (10 CFR 20 Appendix B Table 2). Local, State of North Carolina, and Federal regulators were informed of the abnormal release.

The frequency and types of analyses of water from a nearby creek was increased following this abnormal water loss. Only natural radioactivity has been detected in water collected from the creek. Net unaccounted loss of primary water from the reactor pool was not detectable for all other dates in 2011.

The cause of the unaccounted loss of primary water was determined to be a thermal shock caused by inadvertent operation of the secondary cooling system with the reactor shut down. A secondary pump trip on low reactor pool temperature has been installed to prevent recurrence.

6.7.4.b Energy Output and Critical Hours:

Total Energy Output in 2011: 177.56 Megawatt.days Critical hours in 2011: 4410.27 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br /> Cumulative Total Energy Output Since Initial Criticality: 1441.36 Megawatt.days 6.7.4.c Number of Emergency and Unscheduled Shutdowns:

Emergency Shutdowns - NONE Unscheduled Shutdowns - SEVEN 16APR2011 Loss of commercial power due to thunderstorm. Operator responded as per procedure. Operations resumed once power was restored and after storms cleared the area.

20MAY2011 Reactor SCRAM (manual) due to fire alarm activation. Operator responded as per procedure. No actual fire existed. Operations resumed after building cleared by Fire Marshall.

01JUN2011 Loss of commercial power due to power flicker. Operator responded as per procedure. Operations resumed once power was restored.

03JUN2011 Reactor SCRAM (automatic) due to failed UPS. Operator responded as per procedure. UPS replaced with spare unit.

18JUN2011 Loss of commercial power due to power flicker. Operator responded as per procedure. Operations resumed once power was restored.

12SEP2011 Reactor SCRAM (manual) due to normal testing of radiation interlocks. No actual high radiation condition existed. Operator was retrained in the proper response to High Radiation Entry Alarms during normal testing of interlock devices.

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29NOV2011 Reactor SCRAM (manual) due to normal testing of radiation interlocks. No actual high radiation condition existed. Operator was retrained in the proper response to High Radiation Entry Alarms during normal testing of interlock devices.

6.7.4.d Corrective and Preventative Maintenance:

Preventative maintenance, tests and calibrations are scheduled, performed and tracked utilizing the PULSTAR Surveillance File System. Each major component of the Reactor Safety System defined in Section 3.3, and all surveillance required by Section 4 of the Technical Specifications are monitored by this file system to ensure that maintenance and calibrations are performed in a timely manner. All historical data relating to those components, in addition to many other sub-systems, are maintained in these files.

0770 N-16 Meter. Digital Meter replaced with spare unit and calibrated.

0771 PN Photo Eye. Light source for Pneumatic Sample in Reactor was replaced with spare unit.

0772 Primary Demineralizer Pump Seal. The shaft seal of the demineralizer pump was replaced due to leakage.

0773 Control Distribution UPS. The UPS was replaced due to failed logic board internal to the UPS.

0774 Pool Liner. A pool leak developed in the pool liner. A leak detection company located the leak and the leak was patched.

0775 T2 Temperature RTD. The insulation for the Pool RTD (T2) failed causing a short and failed low indication. The unit was replaced with spare unit and calibrated.

0776 Secondary Pump. The secondary pump was replaced with a new unit. This was a predictive maintenance item.

0777 Primary Demineralizer Pump Motor Contactor. The contactor in the motor starter unit failed. The contactor was replaced.

0778 Reactor Air Compressor Belt. The belt failed and was replaced.

6.7.4.e Changes in Facility, Procedures, Tests, and Experiments:

Facility Changes Design changes to the reactor facility were reviewed to determine whether or not a 10CFR50.59 evaluation was required. Based on the reviews, none required a 10CFR50.59 evaluation.

The following design changes were made:

0713 Neutron Imaging Facility Modification. Installation of interlock and safety equipment for the Neutron Imaging Facility.

0720 Reactor ON Sign Modification. Added two Reactor ON and percent power level indication signs on the bay floor to inform experimenters of the status of the reactor.

0722 Neutron Diffraction Facility Modification. Installation of interlock and safety equipment for the Neutron Diffraction Facility.

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0723 Neutron Imaging Facility Modification. Installation of a RFID proximity reader which provides entry permit into the Neutron Imaging Facility.

0728 Secondary Pump Trip. Modification that added automatic secondary pump trip and alarms on low coolant temperature conditions to prevent inadvertent cool-down of the reactor pool water and pool liner.

Document Changes Procedure changes were reviewed to determine whether or not a 10CFR50.59 evaluation was required. Based on the reviews, none required a 10CFR50.59 evaluation.

0714 NRP-XP-102 Neutron Imaging Facility. New procedure for the daily testing and use of the Neutron Imaging Facility.

0715 NRP-OP-104 Reactor Experiments. Added user responsibilities and training requirements for the use of irradiation facilities.

0716 Modification and Maintenance Review.

0717 NRP-OP-105 Response to SCRAMS, Alarms and Abnormal Conditions. Added reactor operator guidance for the proper response to Neutron Imaging Facility alarms.

0718 Emergency Procedure 2 - Offsite Notification. Updated authentication code list for calendar year 2011.

0719 NRP-XP-101 Experimental Facilities. New procedure to provide safety and operating instructions for experimental facilities.

0721 NRP-XP-103 Neutron Diffraction Facility. New procedure for the daily testing and use of the Neutron Diffraction Facility.

0724 NRP-XP-102 Neutron Imaging Facility. Changes to procedure to reflect the installation of the RFID proximity reader which permits entry into the Neutron Imaging Facility.

0725 NRP-XP-101 Experimental Facilities. Change reflects that instructions regarding the Neutron Diffraction Facility were moved to a separate procedure.

0726 Emergency Procedure :2 - Offsite Notification. Update of American Nuclear Insurers telephone number per ANI Information Bulletin 11-01.

0727 Emergency Procedure 1 - Emergency Plan Activation, Response, and Actions. Updated contact phone numbers on Attachment 8.

0729 NRP-OP-105 Response to SCRAMS, Alarms and Abnormal Conditions.

Test and Experiments There were no new experiments or changes to existing experiments.

Other Changes There were no other changes.

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6.7.4.f Radioactive Effluent:

Liquid Waste (summarized by quarters)

i. Radioactivity Released During the Reporting Period:

Releases to the sanitary sewer are given below:

(1) (2) (3) (4)1 (5)

Period Number of Total Total Diluent Tritium Batches [tCi Volume Liters Liters 01 JAN - 31 MAR 11 2 26.8 5.14 E3 2.80 E3 26.1 01 APR - 30 JUN 11 2 26.4 6.10 E3 8.26 E3 25.0 01 JUL - 30 SEP 11 8 1304.0 2.61 E4 5.50 E4 1296.0 01 OCT- 31 DEC 11 1 107.0 2.77 E3 3.71 E2 106.6 2011 1454 pCi of tritium was released during this year.

2011 1465 pCi of total activity was released during this year.

'Based on gross beta activity only. Tritium did not require further dilution.

Releases to unrestricted areas:

Period Total Total Volume Tritium lPCi Liters uCi 01 JUL- 14 JUL 11 3378 1.35 E4 3104 In July 2011 an unaccounted loss of approximately 1.35 E4 liters (3569 gallons) of primary water occurred over a period of 14 days. The water loss stopped following the detection and repair of a leak site in the reactor pool liner. It was assumed the water was leaking into the ground surrounding the reactor site. The radioactivity present in the reactor water met regulatory limits for release to unrestricted areas (10 CFR 20 Appendix B Table 2) for the 14 day release.

ii. Identification of Fission and Activation Products:

The gross beta-gamma activity of the batches in (i) above were less than 2x10 5 PCi/ml. Isotopic analyses of these batches indicated low levels of typical corrosion and activation products. No fission products were detected.

iii. Disposition of Liquid Effluent not Releasable to Sanitary Sewer System:

All liquid effluent met the requirements of 10CFR20 for release to the sanitary sewer.

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Gaseous Waste (summarized monthly)

i. Radioactivity Discharged During the Reporting Period (in Curies) for:

(1) Gases:

Year Month Total Time Curies Hours 2011 JANUARY 744 1.367 FEBRUARY 672 2.261 MARCH 744 2.248 APRIL 720 2.467 MAY 744 2.874 JUNE 720 1.749 JULY 744 0.881 AUGUST 744 1.301 SEPTEMBER 720 0.359 OCTC)BER 744 1.112 NOVEMBER 720 0.381 DECEMBER 744 0.658 TOTAL 8760 17.658 (2) Particulates with a half-life of greater than eight days:

Particulate filters from the Stack Particulate Monitoring Channel were analyzed upon removal.

There was no particulate activity with a half-life greater than 8 days indicated on any filter during this reporting period.

ii. Gases and Particulates Discharged During the Reporting Period:

(1) Gases:

Total activity of Argon-41 released was 17.658 curies in 2011.

The yearly average concentration of Argon-41 released from the PULSTAR reactor facility exhaust stack in 2011 was 6.6x10-8 pCi/ml. Dose calculations for the year were performed using methods given in the Final Safety Analysis Report. Dose calculations gave results less than the 10 CFR 20 constraint level of 10 mrem. These results are consistent with environmental monitoring data given in Attachment A.

(2) Particulates:

Refer to gaseous waste i.(2) above.

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Solid Waste from Reactor

i. Total Volume of Solid Waste Packaged 31 ft3 of dry uncompacted waste.

No spent ion exchange resins were disposed.

ii. Total Activity Involved 0.022 mCi of dry uncompacted waste.

No spent ion exchange resins were disposed.

iii. Dates of shipments and disposal Transfer to the university broad scope radioactive materials license was made on 11 Sep 2011.

The University Environmental Health and Safety Center arranges disposal of hazardous wastes.

6.7.4.g Personnel Radiation Exposure Report:

30 individuals were monitored for external radiation dose during the reporting period. Internal dose monitoring was not required for any individual. Collective deep dose-equivalent for 1 Jan 2011 to 31 Dec 2011 was 4.791 person-rem. Individual deep dose-equivalent ranged from 0.006 rem to 1.259 rem with a median of 0.075 rem.

6.7.4.h Summary of Radiation and Contamination Surveys Within the Facility:

Radiation and contamination surveys performed within the facility indicated that:

• Radiation in the majority of areas was 5 mrem/h or less.

• Radiation in the remaining areas were higher due to reactor operations.

• Contamination in most areas was not detectable. When contamination was detected, the area or item was confined or decontaminated.

6.7.4.i Description of Environmental Surveys Outside of the Facility:

Refer to Attachment A for results of environmental sampling and analysis.

Radiation surveys performed in unrestricted areas near the reactor facility indicated that:

Radiation was at background levels for most areas (average background is approximately 10 prem/h).

Contamination was not detectable.

Net radiation readings ranged from 0 to 50 prem/h while the reactor was operating at power. However, radiation was at background levels in all routinely occupied spaces.

Water samples from Rocky Branch Creek were analyzed from 14 Jul 2011 to 14 Oct 2011 for tritium, gross beta activity, gross alpha activity, and gamma radiation following the loss of primary water. All sample results were consistent with background radioactivity.

Environmental monitoring of Rocky Branch Creek is routinely performed in accordance with facility procedures.

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ATTACHMENT A PULSTAR REACTOR ENVIRONMENTAL. RADIATION SURVEILLANCE REPORT FOR THE PERIOD JANUARY 1, 2011 - DECEMBER 31, 2011 NORTH CAROLINA STATE UNIVERSITY ENVIRONMENTAL HEALTH AND SAFETY CENTER RADIATION SAFETY DIVISION by Ralton J. Harris Environmental Health Physicist

TABLE OF CONTENTS PAGE NO.

1. INTRODUCTION 1 Table 1 Environmental Monitoring Programs for the PULSTAR Reactor 2

2. AIR MONITORING 3 Table 2.1 Location of Air Monitoring Stations 3 Table 2.2 Aerially Transported Gamma Activity (LLD Values) 4 Figures 2a-2e Airborne Gross Beta Activities 5-9 Table 2.3 Regulatory Limits, Alert Levels and Background Levels for Airborne Radioactivity 10

3. MILK Table 3.1 1-131 in Cow's Milk 11

4. SURFACE WATER Table 4.1 Gross Alpha and Beta Activity in Surface Water 12 Table 4.2 LLD Values for Gamma Emitters in Surface Water 13

5. VEGETATION Table 5.1 Gross Beta Activity in Campus Vegetation 14 Table 5.2 LLD Values for Gamma Emitters in Vegetation 15

6. THERMOLUMINESCENT DOSIMETERS 16 Table 6.1 Environmental TLD Exposures 17

7. QUALITY CONTROL INTERCOMPARISON PROGRAM 18 Tables 7.1a - 7.1d 19 - 22

8. CONCLUSIONS 23 APPENDIX I 24 - 28

1. INTRODUCTION The Environmental Radiation Surveillance Program exists to provide routine measurements of the university environment surrounding the PULSTAR Reactor.

The specific objectives of this program include:

1) Providing information that assesses the adequacy of the protection of the university community and the public-at-large;

2) Meeting requirements of regulatory agencies;

3) Verifying radionuclide containment in the reactor facility;

4) Meeting legal liability obligations; and

5) Providing public assurance and acceptance.

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Table 1:

Environmental Monitoring Programs for the PULSTAR Reactor at North Carolina State University Sample Activity Conducted Previous Current Basis For Measured By Frequency Frequency Measurement Stack Gross N.E. Continuous Continuous 10 CFR 20 Gases Gamma T.S. 6.7.4 Stack Gross Beta N.E. Monthly Monthly 10 CFR 20 Particles Gamma N.E. T.S. 6.7.4 Emitters Water from Gross Beta N.E. Prior to Prior to 10 CFR 20 Reactor Gross N.E. Discharge Discharge T.S. 6.7.4 Facility Gamma N.E. (~ Monthly) - Monthly City of Tritium Raleigh Ordinance Air/Particles Gross Beta RSD/EHSC Weekly Quarterly 10 CFR 20 at 5 Indiv. RSD/EHSC Weekly 10 CFR 20 Campus Gamma Stations* Emitters Air/Dosage TLD RSD/EHSC Quarterly Quarterly 10 CFR 20 at 8 Dosimeter Campus Stations+

Surface Gross Beta RSD/EHSC Quarterly Quarterly NCSU Water Indiv. RSD/EHSC Quarterly Quarterly NCSU Rocky Gamma Branch Emitters Creek Vegetation Gross Beta RSD/EHSC Semi- Alternate years NCSU NCSU Gamma RSD/EHSC annually Alternate years NCSU Campus Milk 1-131 RSD/EHSC Monthly Alternate years NCSU Local Dairy Abbreviations Used in Table:

N.E. = Nuclear Engineering/Reactor Facility; RSD/EHSC = Radiation Safety Division.

• These 5 stations include:

Withers, Daniels, Broughton, D.H. Hill Library and Environmental Health & Safety Center.

+These 8 stations include: the PULSTAR stack, a control station (EHSC) and the 5 air sampling stations, and North Hall.

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2. AIR MONITORING (TABLES 2.1, 2.2, AND 2.3; FIGURES 2a THROUGH 2e)

Air monitoring is performed continually for one week during each of four (4) quarters during the year. The data shows the normal fluctuations in gross beta activity levels expected during the year. Figures 2a through 2e show bar graphs of gross beta activity (fCi/cubic meter vs. sampling quarters per year). The highest gross beta activity observed was 19.6 fCiM 3at the D.H. Hill Library station during the week of 03/24/11 to 03/31/11. The annual campus average was 11.4 fCiM -.

Table 2.2 lists LLD values for several gamma emitters which would be indicative of fission product activity. No gamma activity due to any of these radionuclides was detected.

Table 2.3 lists regulatory limits, alert levels, and average background levels for airborne radioactivity.

TABLE 2.1 LOCATION OF AIR MONITORING STATIONS 2 3 SITE DIRECTION 1 DISTANCE ELEVATION (meters) (meters)

BROUGHTON SOUTHWEST 125 -17 LIBRARY NORTHWEST 192 +11 DANIELS SOUTHEAST 90 -8 WITHERS NORTHEAST 82 -6 EH & S CENTER WEST 1230 -3 NORTH HALL NORTHEAST 402 -4 1 DIRECTION - DIRECTION FROM REACTOR STACK 2 DISTANCE

- DISTANCE FROM REACTOR STACK 3 ELEVATION

- ELEVATION RELATIVE TO THE TOP OF THE REACTOR STACK 3

Table 2.2 Aerially Transported Gamma Activity LLD values fCi/cubic meter NUCLIDES SAMPLING PERIOD Co-57 Co-60 Nb-95 Zr-95 Ru-103 Ru-106 Cs-137 Ce-141 Ce-144 2011 03/24 - 03/31 0.21 0.35 0.29 0.47 0.27 2.37 0.26 0.38 1.22 05/20 - 05/26 0.2 0.37 0.28 0.48 0.28 2.48 0.29 0.34 1.28 09/23 - 09/29 0.18 0.35 0.31 0.54 0.33 2.51 0.29 0.43 1.40 12/09 - 12/16 0.17 0.37 0.37 0.50 0.32 2.41 0.29 0.39 1.41

Broughton Hall Airborne Gross Beta Activity 25 Figure 2a 20 E-03/24-03/31 05/20-05/26 0 15 Z 2011 2011 09/23-09/29 2011 12/09-12/16 10 2011 5

0-1 2 3 4 Quarters per Year

Withers Hall 25 Airborne Gross Beta Activity Figure 2b 05/20-05/26 20 2011 15 03/24-03/31 09/23-09/29 12/09-12116 E 15 2011 2011 2011 Z

.0 5 0 t I 1 2 3 4 Quarters per Year

Daniels Hall 25 Airborne Gross Beta Activity Figure 2c 09123-09129 20 2011120126 2011 E 15 03/24-03/31 05/12-05/26 2011 2011 Z

~10 5/

0 /

2 3 4 Quarters per Year

D.H. Hill Library Airborne Gross Beta Activity 30 Figure 2d 25 03124-03131 20 2011 ENO 05/20-05/26 09/23-09/29 12/09-12/16 2011 2011 2011 210 5

0 1 2 3 4 Quarters per Year

Environmental Health & Safety Center Airborne Gross Beta Activity 25 Figure 2e 2I-3 09/23-09/29 12/09-12/16 20 2011 2011

.03/24-03/31 E 15 2011 05/20-05/26 2011 2011 10 5

0 1 2 3 4 Quarters per Year

TABLE 2.3 REGULATORY LIMITS, ALERT LEVELS, AND BACKGROUND LEVELS FOR AIRBORNE RADIOACTIVITY (fCi M -3).

REGULATORY INVESTIGATION *AVERAGE N.C.

NUCLIDE LIMIT LEVEL BACKGROUND LEVEL GROSS BETA 1000 500 20 Cs-1 37 2 X 105 100 2 Ce-1 34 2 X 105 100 0 Nb-95 2X 106 100 0 Zr-95 400 100 0 This data represents an average value measured in North Carolina at various locations.

Excerpted from 2009 Environmental Surveillance Report produced by the NC Department of Environment & Natural Resources Division of Environmental Health Radiation Protection Section.

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3. MILK (TABLE 3.1)

Milk samples are collected in alternate years from the Campus Creamery and the Lake Wheeler Road Dairy and analyzed for 1-131. Data given for 2011 show that no 1-131 activity was detected.

TABLE 3.1A 1-131 IN COW' S MILK (pCi Liter 1 +/- 2 (Y) LLD - 2 pCi Liter-pCi Liter- 1 DATE Campus Creamery Lake Wheeler October 2011 <2 <2 11

4. SURFACE WATER (TABLES 4.1 AND 4.2)

Table 4.1 gives the gross alpha and beta activities for water from Rocky Branch at points where it enters (ON) and exits (OFF) the campus. The LLD value for gross alpha and beta activities is - 0.4 pCi Liter 1 . For gross alpha activity the Alert Level is 5 pCi Liter-1 and the Regulatory Limit is 15 pCi Liter 1 . For gross beta activity the Alert Level is 5 pCi Liter 1 and the Regulatory Limit is 50 pCi Liter1 .

Samples with gross alpha or beta activities exceeding these Alert Levels would require gamma analysis to identify the radionuclides present. All the results are consistent with the presence of naturally-occurring radionuclides and none of the gamma emitters listed in Table 4.2 were detected.

TABLE 4.1 GROSS ALPHA AND BETA ACTIVITY IN SURFACE WATER (pCi Liter 1 +/- 2r)

LLD, - 0.4 pCi Liter 1 LLDO - 0.4 pCi Liter -1 pCi Liter-1 GROSS GROSS DATE LOCATION ALPHA BETA FIRST QUARTER 2011 ON < 0.4 2.8 +/- 0.7 OFF < 0.4 2.5 +/- 0.7 SECOND QUARTER 2011 ON < 0.4 3.4 +/- 0.7 OFF < 0.4 3.4 +/- 0.7 THIRD QUARTER 2011 ON < 0.4 3.1 +0.7 OFF < 0.4 2.8+0.7 FOURTH QUARTER 2011 ON < 0.4 3.5+0.7 OFF < 0.4 3.3+0.7 12

TABLE 4.2 LLD VALUES FOR GAMMA EMITTERS IN SURFACE WATER NUCLIDE LLD (pCi Liter-1)

Co-60 0.4 Zn-65 0.7 Cs-137 0.3 Cs-134 0.4 Sr-85 0.4 Ru-103 0.3 Ru-106 3.0 Nb-95 0.4 Zr-95 0.5 13

5. VEGETATION (TABLE 5.1 & 5.2)

Tables 5.1 gives gross beta activities for grass samples collected on the NCSU Campus. Table 5.2 lists LLD values for several gamma emitters. The vegetation sampling is performed in alternate years.

All the results are consistent with the presence of naturally-occurring radionuclides and none of the gamma emitters listed in Table 5.2 were detected.

1 TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION

• LLD - 0.5 pCi g-SAMPLE DATE SAMPLE LOCATION {2PLiq'+/- 2cy) 10/20/2011 NORTH CAMPUS 8.3 +/-0.5 10/20/2011 SOUTH CAMPUS 4.4 +/-0.5 10/20/2011 EAST CAMPUS 6.8 +/-0.5 10/20/2011 WEST CAMPUS 4.2 +/-0.4 14

TABLE 5.2 LLD VALUES FOR GAMMA EMITTERS IN VEGETATION NUCLIDE LLD (pCi qram 1 )

Co-60 0.01 Zn-65 0.02 Cs-137 0.01 Cs-134 0.01 Sr-85 0.01 Ru-103 0.01 Nb-95 0.01 Zr-95 0.02 15

6. THERMOLUMINESCENT DOSIMETERS (TLDs) (TABLE 6.1)

TLD analysis is contracted to Landauer, Inc. for determination of ambient gamma exposures.

Exposures are integrated over a three-month period at each of the five air monitor stations listed in Table 2.1 and inside the PULSTAR Reactor stack and at North Hall. A control station is located in Room 107 of the Environmental Health & Safety Center. Table 6.1 gives the data for these eight (8) locations.

The exposures (dose equivalents) are reported as millirem per quarter year. Readings which fall below the dosimeters' minimum measurable quantities (i.e., 1 millirem for gamma radiations and 10 millirems for beta radiations) are reported by the contract vendor with the designation "M". The observed readings are all within the expected range for natural background radiation levels.

Historically, dosimeter readings for D.H. Hill Library monitoring station have often been higher than those for the other campus stations due to its location inside a concrete penthouse. Pursuant to a recommendation made in the NCSU PULSTAR 2001 Annual Self Assessment, two additional TLDs are included at the D.H. Hill Library station to supplement the existing dosimeter. These two additional dosimeters are a routine part of the quarterly monitoring schedule.

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TABLE 6.1 ENVIRONMENTAL TLD EXPOSURES (mrem/QUARTER YEAR)

DATE WITHERS DANIELS BROUGHTON DH HILL* EH&S PULSTAR NORTH CONTROL 2011 01/01-03/31 2 9 8 28,23,26 9 33 7 M,3 04/01-06/30 M 2 3 36,16,25 6 22 3 M,3 07/01-09/30 4 6 7 25,23,21 10 21 7 M,8 10/01-12/31 1 4 4 18,23,27 7 31 6 M,5

• Entries for D.H. Hill are for three (3) independent dosimeter readings for that station.

Entries for CONTROL are for two (2) independent dosimeter readings in two (2) separate office locations.

The designation "M" is used by the contract vendor for reporting dose equivalents below the minimum measurable quantity which is 1 millirem for gamma radiation and 10 millirem for beta radiation r-_

All values reported are Deep DDE

7. QUALITY CONTROL INTERCOMPARISON PROGRAM The Environmental Radiation Surveillance Laboratory (ERSL) of the Radiation Safety Division has analyzed samples provided by the U.S. DOE Mixed-Analyte Performance Evaluation Program (MAPEP Test Session 24) Radiological and Environmental Sciences Laboratory (RESL) during this reporting period. The objective of this program is to provide laboratories performing environmental radiation measurements with unknowns to test their analytical techniques.

The MAPEP value listed in the Tables 7.1 (a-d) to which the ERSL results are compared is the mean of replicate determinations for each nuclide. The MAPEP uncertainty is the standard error of the mean.

For each reported radiological and inorganic analyte, the laboratory result and the RESL reference value may be used to calculate a relative bias:

%Bias = (100)(Laboratory Re sult - RESL Re ferenceValue)

RESL Re ferenceValue The relative bias will place the laboratory result in one of three categories:

Acceptable ..................... Bias < 20%

Acceptable with Warning... 20% < Bias < 30%

Not Acceptable ................ Bias > 30%

The typical calculations employed for this program are shown in an example calculation in Appendix 1.

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I - _.

TABLE 7.1a GROSS ALPHA & BETA ACTIVITY AIR FILTER--INTERCOMPARISON STUDY 01 February 2011 The sample consists of one 50 mm diameter simulated filter spiked with a matrix-free solution containing a single alpha and a single beta emitting nuclide. The reported values and the known values are given in Bq/filter,.

• NCSU - ENVIRONMENTAL LABORATORY RESULTS Radionuclide *Reported *Reported MAPEP Acceptance Value Error Value Range Gross Alpha 0.396 0.021 0.659 0.198 - 1.120 Gross Beta 1.23 0.03 1.323 0.662 - 1.985 19

TABLE 7.1b MULTINUCLIDE AIR FILTER - INTERCOMPARISON STUDY 01 February 2011 The sample consists of one 7 cm diameter glass fiber filter which has been spiked with 0.10 gram of solution and dried. The reported values and the known values are given in Bq/filter.

• NCSU - ENVIRONMENTAL LABORATORY RESULTS Radionuclide *Reported *Reported MAPEP Acceptance Value Error Value Range Co60 0.05 0.10 False + Test Cs137 2.15 0.11 2.28 1.60 - 2.96 Cs134 2.45 0.08 3.49 2.44 - 4.54 Co57 3.10 0.13 3.33 2.33 - 4.33 Mn54 2.71 0.13 2.64 1.85 - 3.43 Zn65 3.68 0.23 3.18 2.23 -4.13 Note: The entry ......

"" indicates no analyte was present for purposes of conducting a False Positive (+) Test.

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1, TABLE 7.1c MULTINUCLIDE WATER SAMPLE - INTERCOMPARISON STUDY 01 February 2011 The sample consists of a spiked aliquot of acidified water (-5 % HNO 3). The reported values and the known values are given in Bq/Liter.

• NCSU - ENVIRONMENTAL LABORATORY RESULTS Radionuclide *Reported *Reported MAPEP Acceptance Value Eriror Value Range Co60 24.5 1.2 24.6 17.2- 32.0 Cs137 30.5 2.0 29.4 20.6- 38.2 Cs134 18.2 1.0 21.5 15.1- 28.0 Co57 0.75 0.85 False + Test Mn54 33.4 2.1 31.6 22.1 - 41.1 Zn65 0.96 1.00 False + Test Note: The entry" " indicates no analyte was present for purposes of conducting a False Positive (+) Test.

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TABLE 7.1d GROSS ALPHA AND BETA WATER SAMPLE - INTERCOMPARISON STUDY 01 February 2011 The sample consists of a 5% HNO 3 matrix free solution. The reported values and the known values are given in Bq/Liter.

• NCSU - ENVIRONMENTAL LABORATORY RESULTS Radionuclide *Reported *Reported MAPEP Acceptance Value Error Value Range Gross Alpha 1.62 0.08 1.136 0.341 - 1.931 Gross Beta 3.56 0.09 2.96 1.48-4.44 22

• *I b

8. CONCLUSIONS The data obtained during this period do not show any fission product activities. The observed environmental radioactivity is due primarily to radon progeny, primordial radionuclides (e.g. K-40) and those radionuclides which originate in the upper atmosphere as the result of cosmic ray interactions. These facts justify the conclusion that the PULSTAR Reactor facility continues to operate safely and does not release fission product materials into the environment.

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APPENDIX I The following example calculation gives a set of data, the mean value, the experimental sigma, and the range. These statistics provide measures of the central tendency and dispersion of the data.

The normalized range is computed by first finding mean range, R, the control limit, CL, and the standard error of the range, OR. The normalized range measures the dispersion of the data (precision) in such a form that control charts may be used. Control charts allow one to readily compare past analytical performance with present performance. In the example, the normalized range equals 0.3 which is less than 3 which is the upper control level. The precision of the results is acceptable.

The normalized deviation is calculated by computing the deviation and the standard error of the mean, crm. The normalized deviation allows one to measure central tendency (accuracy) readily through the use of control charts. Trends in analytical accuracy can be determined in this manner.

For this example, the normalized deviation is -0.7 which falls between +2 and -2 which are the upper and lower warning levels. The accuracy of the data is acceptable. Any bias in methodology or instrumentation may be indicated by these results.

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F.

EXAMPLE CALCULATIONS Experimental Data:

Known value = p = 3273 pCi 3H/Liter on September 24, 1974 Expected laboratory precision = a 357 pCi/liter Sample Result X, 3060 pCi/liter X2 3060 pCi/liter X3 3240 pCi/liter Mean =x N

E xi.9360 x = ___ 3 3120 pCi/liter N

where N = number of results = 3 Experimental sigma = s N.

N (E X.) 2 N

i2i (3060+3060+32'40)2 (3060)2+(3060)2+ (3240)2-3 s 2 s = 103.9 pCi/liter Range r r = lmaximum result - minimum result I r = 1240 - 30601 r = 180 pCi/liter 25

Range Analysis (RNG ANLY)*

Mean range =

= d2o where d2** = 1.693 for N=3

= (1.693) (357)

R = 604.4 pCi/liter Control limit = CL CL = R + 3oR

= D4R where D4** = 2.575 for N = 3

= (2.575) (604.4)

CL = 1556 pCi/liter Standard error of the range =

GR = (R + 3oR- R)+ 3

= (D 4R- R) + 3

= (1556- 604.4) 3 C = 317.2 pCi/liter Let Range = r = wR + xoR = 180 pCi/liter Define normalized range = w+x for r >- R,w = 1 then r = WR+XOR = R + XOR r-R or x ---------------

COR r-R therefore w+x = 1 +x = 1+

OR

• Rosentein, M., and A. S. Goldin, "Statistical Techniques for Quality Control of Environmental Radioassay,"

AQCS Report Stat-1, U.S. Department of Health Education and Welfare, PHS, November 1964.

• • From table "Factors for Computing Control Limits," Handbook of Tables for Probability and Statistics, 2nd Edition, The Chemical Rubber Co., Cleveland, Ohio, 1968, p. 454.

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for r

• R, x = 0 then r = wR+xoR = wR r

or W=

R r

therefore w+x = w+0 =

R since r < R, (180 < 604.4) 180 W+X=

604.4 w + x = 0.30 Normalized deviation of the mean from the known value = ND Deviation of mean from the known value = D D =x-p

= 3120 - 3273 D = -153 pCi/liter Standard error of the mean = cm a

Om VN 357 V/3 a, = 206.1 pCi/liter D

NDD OM

-153 206.1 ND = -0.7 Control limit = CL CL = (p t 3om) 27

Warning limit = WL WL = (p +/-2om)

Experimental sigma (all laboratories) =s N

-2___2- i=1 St N-

- (49345)2 162639133 15 14 st = 149 pCi/liter Grand Average = GA N

GA - _=1 N

49345 15 GA = 3290 pCi/liter Normalized deviation from the grand average = ND' Deviation of the mean from the grand average = D' D'= T- GA

= 3120 - 3290 D'= -170 pCi/liter

=

ND m

-170 206.1 ND' = -0.8 28