ML13092A102

North Carolina State University - Annual Report for 2012

ML13092A102
Person / Time
Site:	North Carolina State University
Issue date:	03/28/2013
From:	Hawari A North Carolina State University
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML13092A102 (32)

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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 I-ql An Equal Opportunity/Affirmative Action Employer Nuclear Reactor Program Campus Box 7909 Raleigh, North Carolina 27695 http://www.ne.ncsu.edu/nrp/index.html Director 919.515.4598 Office 919.515.7294 (Fax) 919.513.1276 Shipping Address:

NC State University 2500 Stinson Dr.

Raleigh, NC 27695 28 March 2013 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 wicks@ncsu.edu.

I declare under penalty of perjury that the forgoing is true and correct. Executed on 28 March 2013.

Ayman I. Hawari, Ph. D.,

Director, Nuclear Reactor Program North Carolina State University

Enclosures:

Annual Operating Report for 2012 Attachment A: PULSTAR Reactor Environmental Radiation Surveillance Report A09_

NORTH CAROLINA STATE UNIVERSITY DEPARTMENT OF NUCLEAR ENGINEERING PULSTAR REACTOR ANNUAL REPORT DOCKET NUMBER 50-297 For the Period: 01 January 2012 - 31 December 2012 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.

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

• Sediment/soil/rocks

• Silicon crystals I

• Textiles

• Water 719 Nuclear Services Isotope Production Reactor Utilization - 2012 1%

717 Research Using Special Irradiation Facility 1% 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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6.7.4.b Energy Output and Critical Hours:

Total Energy Output in 2012: 65.6 Megawatt.days Critical hours in 2012: 1580.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Cumulative Total Energy Output Since Initial Criticality: 1504.6 Megawatt-days 6.7.4.c Number of Emergency and Unscheduled Shutdowns:

Emergency Shutdowns - NONE Unscheduled Shutdowns - Eight 27-JUNE-2012 Reactor SCRAM - Flapper NOT Closed SCRAM - The flapper not closed SCRAM works using a micro-switch with very little tolerance. The flapper was closed, but not making good contact with the micro-switch. The micro-switch was reset and tested satisfactorily. The reactor was cleared for restart.

16-AUG-2012 Reactor SCRAM - Linear Level Monitor Over-Power SCRAM - The SCRAM was caused by the auto ranging function not ranging fast enough during an increase in power. No actual over power condition existed. The reactor was cleared for restart.

16-AUG-2012 Reactor SCRAM - Flapper NOT Closed SCRAM - The flapper not closed SCRAM works using a micro-switch with very little tolerance. The flapper was closed, but not making good contact with the micro-switch. The micro-switch was reset and tested satisfactorily. The reactor was cleared for restart.

10-SEP-2012 Reactor SCRAM - Flapper NOT Closed SCRAM - The flapper not closed SCRAM works using a micro-switch with very little tolerance. The flapper was closed, but not making good contact with the micro-switch. The micro-switch was cleaned, reset and tested satisfactorily. A replacement was ordered. The reactor was cleared for restart.

03-OCT-2012 Reactor SCRAM - A reactor SCRAM occurred due to a static discharge from the reactor operator touching the Linear Level Monitor. The reactor was cleared for restart.

16-OCT-2012 Reactor SCRAM - Linear Level Monitor Over-Power SCRAM - The SCRAM was caused by the auto ranging function not ranging fast enough during an increase in power. No actual over power condition existed. The reactor was cleared for restart.

31 -OCT-2012 Reactor SCRAM - Manual - The reactor operator initiated a manual SCRAM due to Safety Control Rod #2 not driving in. The down limit switch on the rod drive are double pole switches, one with 120 VAC which provides power to the rod drive motor and one with 24 VAC which provides indication in the control room. The switch was not making full contact with the actuator on the rod drive therefore power was not supplied to the motor. The switch was lubricated and tested satisfactorily. The reactor was cleared for restart.

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08-NOV-2012 Reactor SCRAM - A circuit breaker in the reactor bay lighting panel was manually opened causing the reactor to SCRAM. The breaker was labeled with information regarding this and the reactor was cleared for restart.

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.

779 Regulating Rod Shock Absorber - The shock absorber that cushions the impact when the rod SCRAMS was replaced and all required tests were performed satisfactorily.

780 Control Room HVAC Motor - The motor for the HVAC unit that services the control room was replaced due to worn bearings.

781 Auxiliary Generator- Due to a natural gas outage on campus, a diesel generator was installed as a temporary replacement. The generator was tested daily. When the natural gas supply was restored the Auxiliary Generator was tested satisfactorily and was returned to service.

782 Confinement Fan #1 - The HEPA Filter failed the biennial test and was replaced. The replacement filter tested satisfactorily.

783 Safety Control Rod #2 - The down limit switch was lubricated and tested satisfactorily.

784 LogN and Linear Level Monitor - The isolated output module failed and was replaced.

The Monitor was calibrated satisfactorily.

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:

728 Secondary Pump Trip Modification - To incorporate an automatic secondary pump trip and alarms on low coolant temperature conditions to prevent inadvertent cool down of the reactor pool.

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.

726 Emergency Procedure 2 - Off-Site Notification Rev 17 - Minor Change to update new telephone numbers.

727 Emergency Procedure 1 - Emergency Plan Activation, Response, and Actions Rev 18 -

Minor change to update new telephone numbers.

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729 NRP-OP-105 - Response to SCRAMS, Alarms, and Abnormal Conditions Rev 5 - To provide instructions and set-points for Abnormal Coolant Temperature alarm, with respect to Design Change 728.

730 Rod Drop Time Measurement Modification PS-4-01/02/03-1:Al - Procedure change to allow use of data acquisition unit to measure control rod drop times. The data acquisition unit has been used along with the old equipment for the past seven 7 years and shows that the methods are within 5% of each other. The change was required due to the old equipment becoming obsolete in which parts are no longer available.

731 Shim Rod Travel Time Test PS-4-04-1 :A - Minor change. This is a reaffirmation review.

732 Security Plan 733 NRP-SP-101 - PULSTAR Reactor Security Test and Experiments There were no new experiments or changes to existing experiments.

Other Changes There were no other changes.

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 pCi Volume Liters pCi Liters 01 JAN - 31 MAR 12 3 550 9.57E3 8.20E5 467 01 APR - 30 JUN 12 4 468 1.34 E4 4.36E5 423 01 JUL - 30 SEP 12 7 1060 2.34E4 6.72E5 992 01 OCT- 31 DEC 12 3 346 9.54E3 2.91E5 316 2012 2198 pCi of tritium was released during this year.

2012 2424 pCi of total activity was released during this year.

1Based on gross beta activity only. Tritium did not require further dilution.

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)

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

(1) Gases:

Year Month Total Time Curies Hours 2012 JANUARY 744 1.321 FEBRUARY 696 1.192 MARCH 744 1.205 APRIL 720 0.942 MAY 744 1.066 JUNE 720 1.981 JULY 744 1.656 AUGUST 744 2.029 SEPTEMBER 720 1.719 OCTOBER 744 1.738 NOVEMBER 720 1.399 DECEMBER 744 0.451 TOTAL 8784 16.699 (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 16.699 curies in 2012.

The yearly average concentration of Argon-41 released from the PULSTAR reactor facility exhaust stack in 2012 was 6.3x10-8 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. Low levels of naturally occurring radioactivity were detected.

Solid Waste from Reactor

i. Total Volume of Solid Waste Packaged 61 ft 3 of dry uncompacted waste.

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ii. Total Activity Involved 0.57 mCi of dry uncompacted waste.

iii. Dates of shipments and disposal Transfer to the university broad scope radioactive materials license was made on 1 Feb, 12 Jun, and 29 Aug 2012. The University Environmental Health and Safety Center arranges disposal of hazardous wastes.

6.7.4.g Personnel Radiation Exposure Report:

29 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 2012 to 31 Dec 2012 was 3.420 person-rem. Individual deep dose-equivalent ranged from 0.013 rem to 1.113 rem with a median of 0.085 rem and average of 0.118 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 was 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 in 2012 for tritium, gross beta activity, gross alpha activity, and gamma radiation. 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, 2012 - DECEMBER 31, 2012 NORTH CAROLINA STATE UNIVERSITY ENVIRONMENTAL HEALTH AND SAFETY CENTER RADIATION SAFETY DIVISION by Ralton J. Harris Environmental Health Physicist I

TABLE OF CONTENTS PAGE NO.

1. INTRODUCTION 3 Table 1 Environmental Monitoring Programsfor the PULSTAR Reactor 4

2. AIR MONITORING 5 Table 2.1 Location of Air Monitoring Stations 5 Table 2.2 Aerially Transported Gamma Activty (LLD Values) 6 Table 2.3 Regulatory Limits, Alert Levels and Background Levels for Airborne Radioactivity 6 Figures 2a-2e Airborne Gross Beta Activities 7-9

3. MILK 10 Table 3.1 1-131 in Cow's Milk 10

4. SURFACE WATER 11 Table 4.1 Gross Alpha and Beta Activity in Surface Water 11 Table 4.2 LLD Values for Gamma Emitters in Surface Water 12

5. VEGETATION 13 Table 5.1 Gross Beta Activity in Campus Vegetation 13 Table 5.2 LLD Values for Gamma Emitters in Vegetation 13

6. THERMOLUMINESCENT DOSIMETERS 14 Table 6.1 Environmental TLD Exposures 14

7. QUALITY CONTROL INTERCOMPARISON PROGRAM 15 Tables 7.1a - 7.1e 16-18

8. CONCLUSIONS 19 APPENDIX I 20 - 24 2

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 Indiv. N.E. T.S. 6.7.4 Gamma 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 I I I I I _I Milk 1-131 RSD/EHSC Monthly Alternate years NCSU Local Dairy N.E. = Nuclear Engineering/Reactor Facility; RSD/EHSC = Radiation Safety Division.

• These 5 stations include: Withers, Daniels, Broughton, Hill Library and Environmental Health & Safety Center.

+These 8 stations include: the PULSTAR Reactor, 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 19.3 fCiM -3at the D.H. Hill Library station during the week of 09/10/12 to 09/17/12. The annual campus average was 13.6 fCiM 3.

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 SITE DIRECTION' DISTANCE2 ELEVATION 3 (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 5

TABLE 2.2 AERIALLY TRANSPORTED GAMMA ACTIVITY LLD VALUES Table 2.2 Aerially Transported Gamma Activity ILLD values fCllcubic meter

...... __NUCLIDES SAMPLING PERIOD CO-67 Co-60 Nb-95 Zr-95 Ru-103 Ru-l0 Cs-137 Ce-141 Ce-144 2012 03114 - 0321 0.21 0.35 0.29 0.47 0.27 T 2.37 0.26 0.38 1.22 05/18 -05/24 0.2 0.37 0.28 0.48 0.28 2.48 0.29 0.34 1.28 09110 - 09/17 0.18 0.35 0.31 0.54 0.33 2.51 0.29 0.43 1.40 12/07 - 12/14 0.17 0.37 0.37 0.50 0.32 2.41 0.29 0.39 1.41 TABLE 2.3 REGULATORY LIMITS, ALERT LEVELS, AND BACKGROUND LEVELS FOR AIRBORNE RADIOACTIVITY (fCi M- 3 ).

REGULATORY ALERT AVERAGE N.C.

NUCLIDE LIMIT LEVEL BACKGROUND LEVEL GROSS ALPHA 20 10 4 GROSS BETA* 1000 500 3.3 -13.9" 5

Cs-1 37 5 X 10 10 2 Ce-1 44 2 X 105 100 0 5

Ru-1 06 2 X 10 30 0 1-131 1 X 10 10 0

• These data represent a range of minimum to maximum annual average values measured in North Carolina.

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Broughton Hall 25 T Airborne Gross Beta Activity Figure 2a 03114-03121 2012 05/18-05/24 12107-12114 20- 09/10-09/17 2012 2012 2012 E 15 -+-

.2

.0 10 + 2012 2/071212 5+

0 ---

1 3 4 Quarters per Year 03114-03121 Withers Hall Airborne Gross Beta Activity 25 -

Figure 2b 20 +

1-03/14-03121 09110-09117 12/07-12114 06118-05124 2012 2012 2012 2012 5

0 In NMI -H 1 2 3 4 Quarters per Year 7

Daniels Hall 25- Airborne Gross Beta Activity Figure 2c 03M14-03121 20 0-- 2012 09110-09117 05118-05/24 2012 12107-12114 2012 2012 12-

/

5

/

0 1 2 3 4 Quarters per Year D.H. Hill Library Airborne Gross Beta Activity 30 Figure 2d 25 05118-05/24 09110-09117 12107-12114 20 2012 2012 2012

15 03114-03121 PON" U 2012 10 5

0 1 2 Quarters per Year 3 4 8

Environmental Health & Safety Center Airborne Gross Beta Activity 25- Figure 2e 09110-09117 20- 2012 05118-05/24 0 03114-03121 E 2012 12107-12114 U 2012 2012

.0 MIN/M MON %Y711ý11 U 10 + /I II/

5 E/g/

MIN i 0- .-- i _

I 3 4 Quarters per Year 9

3. MILlK (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. No milk samples were collected for 2012. The next sample collection and analysis will be in 2013.

TABLE 3.1A 1-131 IN COW' S MILK (pCi Liter 1 +/- 2 a) LLD ~ 3 pCi Liter"1 pCi Liter-1 DATE Campus Creamery Lake Wheeler 2012 No Data No Data 10

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 and at an intermediate point near Carmichael Gymnasium (GYM). 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 Liter1 and the Regulatory Limit is 50 pCi Liter-1 . 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 Table4.2 was detected.

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

GROSS ALPHA GROSS BETA pCi Liter 1 pCi Liter-1 DATE LOCATION FIRST QUARTER 2012 ON < 0.4 3.3+/- 0.5 OFF < 0.4 4.6 +/- 0.6 GYM < 0.4 2.7 +/- 0.5 SECOND QUARTER 2012 ON < 0.4 3.5 +/- 0.5 OFF < 0.4 3.4 +/- 0.5 GYM 0.7 +/- 0.3 3.9 +/- 0.5 THIRD QUARTER 2012 ON < 0.4 3D0+0.5 OFF < 0.4 3.0+0.5 GYM < 0.4 3.3+0.5 FOURTH QUARTER 2012 ON < 0.4 5.3+0.6 OFF < 0.4 3.4+0.5 GYM < 0.4 4.0 +/- 0.5

• LLD, - 0.4 pCi Liter1 *LLDP - 0.4 pCi Liter-1 I1

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-1 03 0.3 Ru-106 3.0 Nb-95 0.4 Zr-95 0.5 12

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.

No vegetation samples were collected in 2012. The next sample collection and analysis will be in 2013.

TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION

• LLD - 0.5 pCi g-1 SAMPLE DATE SAMPLE LOCATION t2~ q-1 +/- 2(y) 2012 NORTH CAMPUS No Data 2012 SOUTH CAMPUS No Data 2012 EAST CAMPUS No Data 2012 WEST CAMPUS No Data TABLE 5.2 LLD VALUES FOR GAMMA EMITTERS IN VEGETATION NUCLIDE LLD (pCi gram-1)

Co-60 0.01 Zn-65 0.02 Cs-1 37 0.01 Cs-134 0.01 Sr-85 0.01 Ru-103 0.01 Nb-95 0.01 Zr-95 0.02 13

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 building (In July 2006, the dosimeter previously located in the PULSTAR stack was relocated inside the reactor building at the exhaust duct) and at North Hall. A control station is located in two office locations 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 falling 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.

TABLE 6.1 ENVIRONMENTAL TLD EXPOSURES TABLE 6.1 ENVIRONMENTAL TLD EXPOSURES (norem/QUARTER YEAR)

DATE WITHERSIDANIELS BROUGHTON DHHILL° EH&S PULSTAR NORTH CONTROL 2012 01/01-03/31 M 10 10 33,40,35 8 28 8 M'11 04/01-06130 4 9 9 36,31,29 7 35 10 33,10 07101-09/30 ND ND ND ND ND ND ND ND 10101-12/31 ND ND ND ND ND ND ND ND

• 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.

"ND" indicates no data received from vendor at this time The designation "M" is used by the contract vendor for reporting dose equivalents below the minimum measurable quantity which is 1 millirem for panma radiation and 10 millirem for beta radiation All values reported are Deep DDE I 14

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 27) 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-e) 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 suit - 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%

In addition to the MAPEP Quality Assurance Program, the ERSL conducts an intralaboratory QC program to track the performance of routine radioactivity measurements. The types of calculations employed for this program are shown in an example calculation in Appendix 1.

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TABLE 7.1a GROSS ALPHA & BETA ACTIVITY AIR FILTER--INTERCOMPARISON STUDY 01 August 2012 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 1.4 0.2 0.97 0.29 - 1.65 Gross Beta 1.98 0.42 1.92 0.96 - 2.88 16

TABLE 7.1 b MULTINUCLIDE AIR FILTER - INTERCOMPARISON STUDY 01 August 2012 The sample consists of one 7 cm diameter glass fiber filter that 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 1.69 0.04 1.728 1.210 - 2.246 Cs137 0.1 0.1 False + Test Cs134 1.97 0.04 2.74 1.92-3.56 Co57 1.78 0.04 1.91 1.34-2.48 Mn54 2.38 0.07 2.36 1.65- 3.07 Zn65 0.1 0.1 False + Test "False + Test" indicates no analyte was present in the sample.

TABLE 7.1c MULTINUCLIDE WATER SAMPLE - INTERCOMPARISON STUDY 01 August 2012 The sample consists of a spiked aliquot of acidified water (5% HNQ). 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 Co60 0.5 0.6 False + Test Cs137 16.42 0.65 16.7 11.7-21.7 Cs134 20.7 0.49 23.2 16.2 - 30.2 Co57 29.13 0.75 29.3 20.5 - 38.1 Zn65 27.55 1.34 25.9 18.1- 33.7 Mn54 17.96 0.67 17.8 12.623.1 "False + Test" indicates no analyte was present in the sample.

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TABLE 7.1d GROSS ALPHA AND BETA WATER SAMPLE- INTERCOMPARISON STUDY 01 August 2012 The sample consists of a 5% HNOQ matrix free solution. The reported valuesand 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 0.02 1.79 0.54-3.04 Gross Beta 9.21 0.20 9.1 4.6-13.7 TABLE 7.1e MULTINUCLIDE VEGETATION SAMPLE - INTERCOMPARISON STUDY 01 August 2012 The sample consists of milled hay grass spiked with radiological constituents. The reported values and the known values are given in Bq/sample

• NCSU - ENVIRONMENTAL LABORATORY RESULTS Radionuclide *Reported *Reported MAPEP Acceptance Value Error Value Range Cs134 6.89 0.17 6.51 4.56- 8.46 Cs137 3.42 0.13 4.38 3.075.69 Co57 1.40 2.04 5.66 3.96 - 7.36 Co60 4.35 0.11 5.12 3.586.66 Mn54 3.66 0.22 3.27 2.204.25 Zn65 0.5 0.6 False + Test "False + Test" indicates no analyte was present in the sample.

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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. K40) and those radionuclides that 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, tl-e 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, CR. 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 nornalized range equals 0.3 that 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, am. 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 that 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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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

x = +/-'xl 9360 3120 pCi/liter X'=i 3

where N = number of results = NV Experimental sigma = s N

2~ 1)

N., X1. (i2 -I

= .,=I(x,)2 1 - N-

!(3060 )2 +(3060 ) 2A S =

s = 103.9 pCi/liter Range = r r = maximum result - minimum result r = 3240 -3060 r = 180 pCi/liter 21

Range Analysis (RNG ANLY)*

Mean range = <R>

<R> = d2a whe.re d2** = 1.693 for N =3

= (1.693) (357)

<R> = 604.4 pCi/liter Control limit = CL CL = <R> + 30R

= D4<R> whe=re D4** = 2.575 for N =3

= (2.575) (604.4)

CL = 1556 pCi/liter Standard error of the range = R aR (R + 30R- <R>) + 3

= (D4 <R>-<R>) + 3 (1556-604.4) + 3 R = 317.2 pCi/liter Let Range = r = w<R> + XOR = 180 pCi/liter Define normalized range = w + x forr> <R>, w = 1 then r = w<R> + XOR = <R> + XOR r - <R>

or x -

OR

+ [r - <R>] / OR therefore w +x = 1+x = 1+[r-<R>]/ 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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forr<<R>, x=0 then r = w<R> + XOR = w<R>

or w= rI/<R>

therefore w+x = w+0 = r/<R>

since r <<R>, (180 < 604.4) w + x = 180 /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-

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

am= a / VN

= 357 / V3 am = 206.1 pCi/liter ND = Dlam

= -153/ 206.1 ND = -0.7 Control limit = CL CL = (p +/- 3am) 23

Warning limit = WL WL = (g +/- 2Gm)

Experimental sigma (all laboratories) = st N, (INXx,2 K

Ei 2 i=1 S, =NI (49345)2 162639133

= 15 St = 149 pCi/liter Grand Average = GA N

Exi GA=- '

N 49345 15 GA = 3290 pCi/liter Normalized deviation from the grand average = ND' Deviation of the mean from the grand average =D' D'= x - GA

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

Urn

= -170/206.1 ND' = -0.8 24