ML100910162

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North Carolina State University Annual Report
ML100910162
Person / Time
Site: North Carolina State University
Issue date: 03/29/2010
From: Hawari A
North Carolina State University
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML100910162 (38)
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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 NCSAT UNVRI Department of Nuclear Engineering Campus Box 7909 Raleigh, NC 27695-7909 919.515.2321 919.513.1276 (fax)

URL: www.ne.ncsu.edu/NRP reactor_

program.html 29 March 2010

"'2 Attn: Document Control Desk US Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852 Re: Annual Report 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 2010.

Ayman I. Hawari, Ph. D.,

Director, Nuclear Reactor Program North Carolina State University

Enclosures:

Annual Operating Report for 2009 Attachment A: PULSTAR Reactor Environmental Radiation Surveillance Report

NORTH CAROLINA STATE UNIVERSITY DEPARTMENT OF NUCLEAR ENGINEERING PULSTAR REACTOR ANNUAL REPORT DOCKET NUMBER 50-297 For the Period: 01 January 2009 - 31 December 2009 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.

Technical Specification violation concerning loss of power to the exhaust stack sample pump during reactor operations. On April 13, 2009 it was discovered that the reactor was operated on April 9, 2009 without the minimum number of operable building exhaust monitors as required by TS Section 3.5b. This was reported to the NRC Operation Center on April 14, 2009.

Consequences of this event were not significant. Other radiation monitors were in service to monitor airborne radioactive effluent and reactor bay airborne activity. All of those monitors indicated typical radiation levels during this period. Actions have been taken to prevent recurrence as verified by the NRC in Inspection Report No. 50-297/2010-201.

Operatingexperience including a summary of experimentsperformed.

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 1 of 7

Neutron Activation Analysis

" Crude oil

" Food samples

  • Fish tissues
  • Laboratory animal tissue
  • Human hair, nails, and urine
  • Polymers and plastics
  • Sediment/soil/rocks
  • Textiles
  • Water 2% 11%

0715 Education and Training 31 r1716 Research Using Irradiation Facility 0717 Research Using Special Irradiation Facility 0718 Nuclear Services Neutron Activation Analysis 18719 Nuclear Services Isotope Production 1%

Figure 1 - Reactor Utilization by Protocol

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ii Changes in Performance CharacteristicsRelated 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.

Net loss of primary water from the reactor pool was low, but detectable in 2009. Health physics surveillance of reactor primary coolant water showed no fission products and that activity is below 1 OCFR20, Appendix B, Table 3 limits for all of 2009.

6.7.4.b Energy Output and CriticalHours:

Total Energy Output in 2009: 33.74 Megawatt.days Critical hours in 2009: 975.8 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: 1207.21 Megawatt.days

6. 7.4.c Number of Emergency and Unscheduled Shutdowns:

Emergency Shutdowns - none Unscheduled Shutdowns -THREE

1. 23-APR MANUAL SCRAM - Operator discretion when removing a high reactivity worth sample.
2. 28-JUL FLAPPER NOT CLOSED SCRAM. A FLAPPER NOT CLOSED condition did not actually occur, but was due to not making full closure of the microswitch associated with the SCRAM circuit. The microswitch.was adjusted, reset and tested satisfactorily.
3. 19-AUG FLAPPER NOT CLOSED SCRAM. This was a reoccurrence of the 28-JUL-09 SRAM. The closure of the microswitch has very tight tolerance. Microswitch was readjusted, reset and tested satisfactorily.

6.7.4.d Corrective and PreventativeMaintenance:

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.

0761 - PS-3-01 Primary Pump Replacement - Primary pump failed in December 2008. A replacement was ordered and installed in January 2009.

0762 - PS-7-02-1A - Auxiliary Generator Auto Start - Auxiliary Generator was converted over to automatically start upon loss of building power. See Design Change 682.

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0763 - PS-4-03 Regulating Rod Drive Mechanism - The Regulating Rod Drive Mechanism was not reversing (inserting) during the start-up checklist. The down limit switch was not clearing properly. The switch was adjusted and tested satisfactorily.

0764 - PS-1 6 - Flow/Flapper SCRAM - The Flow/Flapper SCRAM limit switch was not making proper contact. The switch was adjusted, lubricated and tested satisfactorily.

0765 - PS-3-03 Primary Demineralizer Pump - The Primary Demineralizer Pump was leaking greater than 4 gpm. The pump was secured and isolated. The pump seal was replaced.

0766 - PS-1 1 - N-16 Detector - The N-16 detector was replaced.

0767 - PS-2-02 Abnormal Pool Water Switch - The Abnormal Pool Water Switch which alarms at +/-6 inches was not working correctly. The switch was replaced and tested 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:

693 - Primary Pump Replacement - Replacement of the primary pump with minor piping and electrical modifications..

699 - Stack Sample Flow Switch - Installation of flow monitoring switch which will cause a Stack Sample Flow Fault alarm on the reactor control console annunciator. An analog output card was installed in the stack sample flow meter so that the flow rate can be displayed on the radiation recorder.

702 - Thermal Column Modification for UCN Facility - Modification to the thermal column door to accommodate the future installation of the cryogenic cooling lines and neutron guide of the Ultra-Cold Neutron Facility.

Document Changes Procedure changes were reviewed to determine whether or not a I OCFR50.59 evaluation was required. Based on the reviews, none requireda IOCFR50.59 evaluation.

692 - NRP-SP-101 PULSTAR Reactor Security Rev. 2.

696 - Health Physics Procedure 1 - Radiation Protection ProgramRev. 7- Makes administrative and ALARA dose level for personnel consistent with NCSU Radiation Safety Manual.

700- NRP-OP-105 Response to SCRAMS, Alarms and Abnormal Conditions Rev. 3 -Added reactoroperatorinstructions for the Stack Sample Flow FaultAlarm. See Design Change 699.

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Test and Experiments New experiments or changes to experiments 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 changes were made:

684 - Protocol 716 - Research Using IrradiationFacilities- Added a room to the Experiment Protocol which allows for storage of radioactive materials.

705 - Remote Reactor Labs - Review of the safety and security aspects of conducting remote reactorlabs with offsite users.

706 - FSAR Update - Section 14 - NCSU Experimental Program- Update to the description for the Thermal Column Area. The change allows more flexibility in the configuration of the area.

707 - Thermal Column Testing - Review of an untried experiment for benchmarking the thermal column neutron fluxes in support of the Ultra-ColdNeutron Facility. This involves the measurement of reactivity, radiationdose rates, neutron fluxes, and nuclearheating. These types of measurements have been done for other facilities but not for this particularfacility, therefore it was classified as untried.

Other Changes 694 - Security Plan Rev. 11- Changes made to the security plan revision were approved by the NRC. As a result of this revision, ConfirmatoryAction Letter NRR-04-010 is no longer in effect.

6.7.4.f Radioactive Effluent:

Liquid Waste (summarized by quarters)

Radioactivity Released During the Reporting Period:

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

Period Number of Total Total Diluent Tritium Batches pCi Volume Liters 1tCi Batches #Ci Liters 01 JAN- 31 MAR 09 3 70 9.39 E3 2.93 E4 66 01 APR- 30 JUN 09 0 0 0 0 0 01 JUL- 30 SEP 09 2 34 6.27 E3 1.91 E4 32 01 OCT- 31 DEC 09 0 0 0 0 0 2009 98 pCi of tritium was released during this year.

2009 104 pCi of total activity was released during this year.

1 Based 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.

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iii. Dispositionof Liquid Effluent not Releasable to SanitarySewer System:

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

Gaseous Waste (summarizedmonthly)

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

(1) Gases:

Year Month Total Time Curies Hours 2009 JANUARY 744 0.093 FEBRUARY 672 1.590 MARCH 744 0.818 APRIL 720 0.879 MAY 744 0.726 JUNE 720 0.565 JULY 744 0.794 AUGUST 744 0.545 SEPTEMBER 720 0.570 OCTOBER 744 0.536 NOVEMBER 720 0.541 DECEMBER 744 0.393 TOTAL 8760 8.049 (2) Particulateswith 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 ParticulatesDischargedDuring the Reporting Period:

(1) Gases:

Total activity of argon-41 released was 8.049 curies in 2009.

The yearly average concentration of argon-41 released from the PULSTAR reactor facility exhaust stack in 2009 was 3.0x10, 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 10CFR20 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 Total Volume of Solid Waste Packaged 24 ft 3 of dry uncompacted waste.

7 ft 3 of dries ion exchange resins.

ii. Total Activity Involved 0.04 mCi of dry uncompacted waste.

0.23 mCi of dry ion exchange resins.

iii. Dates of shipments and disposal Transfers to the university broad scope radioactive materials license were made on 2 Oct 2009.

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

6. 7.4.g PersonnelRadiation Exposure Report:

26 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 2009 to 31 Dec 2009 was 1.997 person-rem. Individual deep dose-equivalent ranged from 0 to 0.257 rem with an average of 0.066 rem. No visitors required official radiation dose monitoring during 2009.

6.7.4.h Summary of Radiationand ContaminationSurveys Within the Facility:

Radiation and contamination surveys performed within the facility by the PULSTAR staff 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 prepared by the Radiation Safety Division of the Environmental Health and Safety Center at the end of this document for results of environmental sampling and analysis.

Perimeter surveys were performed adjacent to the Reactor Building by the PULSTAR staff and 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.

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ATTACHMENT A PULSTAR REACTOR ENVIRONMENTAL RADIATION SURVEILLANCE REPORT FOR THE PERIOD JANUARY 1, 2009 - DECEMBER 31, 2009 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 - 7.1e 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.

1

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.

2

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 20.6 fCiM 3 at the D.H. Hill Library station during the week of 09/01/09 to 09/07/09. The annual campus average was 9.5 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 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 ILLD values fCi/cubic meter I

I____ I I iNUCLIDES I_

_ _ _ _ _ _ _ _ I _ _ _ _ _ _ i _ _

SAMPLING PERIOD Co-57 I Co-60 I Nb-95 I Zr-95 I Ru-103 Ru-106 I Cs-137 [ Ce-141 Ce-144 2009 02/19- 02/25 0.21 0.35 { 0.29 I 0.47 0.27 2.37 0.26 0.38 1.22 05/21-- 05/28 0.2 0.37 0.28 0.48 1 0.28 2.48 1 0.29 0.34 1.28 09/01 - 09/07 0.181 0.35 0.31 0.54 0.33 2.51 1 0.29 0.43 1.40 11/13- 11/20 0.17 0.37-[ 0.37 0.501 0.32 1 2.41 j 0.29 0.39 -1.41

Broughton Hall 25 -

Airborne Gross Beta Activity Figure 2a 20 -

09/01-09/07 E 15 -

02/19-02/25 2009 0

2009 B

10 - 05/21-05/28 11/13-11/20 2009 2009 5

0 1 2 3 4 Quarters per Year

Withers Hall 25 Airborne Gross Beta Activity Figure 2b 20 I-05/21-05128

0) 2009 09/01-09/07 0, 2009 E 15 C, 11/13-11/20

.0 02/19-02/25 2009 C, 10 2009 U

5 0

1 2 3 4 Quarters per Year

Daniels Hall 25 -

Airborne Gross Beta Activity Figure 2c 20 I- 02/19-02/25 09/01-09/07 2009 11/13-11/20 15 05/21-05/28 2009 2009 C.) 2009 10 5

0 2 3 4 Quarters per Year

D.H. Hill Library Airborne Gross Beta Activity 30 Figure 2d 25 09/01-09/07 2009 020o

.02/19-02/25 05/21-05/28 11/13-11/20 515 -1/10102 2009 2009 2009 5

0 2 3 4 Quarters per Year

Environmental Health & Safety Center Airborne Gross Beta Activity 25 Fiqure 2e 05/21-05/28 2009 09/01-09/07 20 2009 L.

E 15 B/

N 10 002/19-02/25 5 2009 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 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 5X 10 10 2 Ce-144 2X 10 100 0 5

Ru-1 06 2X 10 30 0 5

1-131 1 X 10 10 0

  • These data represent a range of minimum to maximum annual average values measured in North Carolina. Data courtesy of Dale Dusenbury of the N.C. Division of Radiation Protection.

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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 2009 show that no 1-131 activity was detected.

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 May 2009 <3 <3 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 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 Table 4.2 were detected.

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

  • LLD, - 0.4 pCi Liter 1 LLDp - 0.4 pCi Liter-1 pCi Liter-1 GROSS GROSS DATE LOCATION ALPHA BETA FIRST QUARTER 2009 ON < 0.4 3.6 +/- 0.7 OFF < 0.4 2.5 +/- 0.7 SECOND QUARTER 2009 ON < 0.4 3.3 +/- 0.7 OFF < 0.4 3.1 +/-0.7 THIRD QUARTER 2009 ON < 0.4 1.7+0.7 OFF < 0.4 3.0+0.7 FOURTH QUARTER 2009 ON <0.4 2.9+0.7 OFF 0.8 + 2.3 2.4+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-1 37 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 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.

TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION

  • LLD - 0.5 pCi g-1 SAMPLE DATE SAMPLE LOCATION (pQi g-1+/- 20) 09/10/2009 NORTH CAMPUS 5.3 +/-0.4 09/10/2009 SOUTH CAMPUS 5.5 +/-0.5 09/10/2009 EAST CAMPUS 5.5 +/-0.4 09/10/2009 WEST CAMPUS 6.7 +/-0.4 14

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-1 34 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) i__

DATE WITHERS DANIELS

_I_ _

1BROUGHTON iDHHILL* EH&S I I PULSTAR T/NORTHIi _

CONTROL 20091 _ .I1! I_  !

01/01-03/311 2 5 1 1 120,21,47 4 26 2 M,5 I 04/01-06/30 M 8 4 17,10,14 10 1 17 Jf 8 M,6 _

07/01-09/30 M I 1 I M J27,25,26] 8 18 I 5 M,4 _

10/01-12/311 2 8

1 I_

5 36,34,54 I _

9 Ii I 12 I

Bno data** I M,9

_i_

  • Entries for D.H. Hill are for three (3) independent dosimeter readings for that station. _ I Entries for CONTROL are for two (2) independent dosimeter readings in two (2) separate office locations. _
    • The vendor did not provide any reading for this dosimeter

_ _ _ _ _ _ _ _ _ _ _ _ 1

_ _I 1 1 II _ _

I I _ _

1 I _ _

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 I I 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 21) 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 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 July 2009 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 0.91 0.08 0.659 >0.0 - 1.318 Gross Beta 1.35 0.07 1.32 0.66 - 1.98 19

TABLE 7.1b MULTINUCLIDE AIR FILTER - INTERCOMPARISON STUDY 01 July 2009 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 0.921 0.051 1.03 0.72- 1.34 Cs137 1.206 0.092 1.40 0.98- 1.82 Cs134 NR ............

Co57 5.557 0.254 6.48 4.54 - 8.42 Mn54 5.372 0.289 5.49 3.84-7.14 Zn65 4.578 0.256 3.93 2.75 - 5.11 NR = No Result. These were tests for false positive results. No analyte present.

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TABLE 7.1c MULTINUCLIDE WATER SAMPLE - INTERCOMPARISON STUDY 01 July 2009 The sample consists of a spiked, 455 mL aliquot of acidified water (-1 N HCI). 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 15.516 0.874 15.4 10.8 - 20. 0 Cs137 40.933 2.773 41.2 28.8 - 53.6 Cs1 34 31.753 1.408 32.2 22.5 - 41.9 Co57 36.523 3.684 36.6 25.6 - 47.6 Mn54 NR ----.-------

Zn65 31.389 2.948 26.9 18.8 - 35.0.

NR = No Result. These were tests for false positive results. No analyte present.

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TABLE 7.1d GROSS ALPHA AND BETA WATER SAMPLE - INTERCOMPARISON STUDY 01 July 2009 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 1.21 0.32 1.047 > 0.0 - 2.094 Gross Beta 7.17 0.81 7.53 3.77- 11.30 TABLE 7.1e MULTINUCLIDE VEGETATION SAMPLE - INTERCOMPARISON STUDY 01 July 2009 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 NR Cs137 3.142 0.236 2.43 1.70-3.16 Co57 10.835 0.619 8.0 5.6 -10.4 Co60 2.649 0.132 2.57 1.80 - 3.34 Mn54 9.840 0.510 7.9 5.5-10.3 Zn65 NR NR = No Result. These were tests for false positive results. No analyte present.

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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. 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, 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 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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EXAMPLE CALCULATIONS Experimental Data:

Known value = p = 3273 pCi 3 H/Liter on September 24, 1974 Expected laboratory precision = a = 357 pCi/liter Sample Result X1 3060 pCi/liter X2 3060 pCi/liter X3 3240 pCi/liter Mean = x

  • .X;91360

- = X.i = 3 3120 pCi/liter N

where N = number of results = 3 Experimental sigma = s NN N-i (3060+3060+3240)2 (3060)2+ (3060)2+(3240)2- 3 Nj 23 S = 103.9 pCi/liter Range r r = I maximum result - minimum result I r = 3240 - 30601 r = 180 pCi/liter 25

Range Analysis (RNG ANLY)*

Mean range

- 4a where d2** = 1.693 for N = 3

= (1.693) (357)

= 604.4 pCi/liter Control limit - L CL RR+30R where D4** = 2.575 for N = 3

= (2.575) (604.4)

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

OR = (R + 3oR- R)+ 3 (D4R -R) + 3

= (1556- 604.4) 3

= 317.2 pCi/liter Let Range = r = wR + xaR = 180 pCi/liter Define normalized range = w + x for r >- R, w = 1 then r = wR + xOR = R + XOR r-R or r-R therefore w+x = 1 +x = 1 +

  • 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 =--p

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

a'm VN 357 V3 am = 206.1 pCi/liter D

ND-

-153 206.1 ND = -0.7 Control limit = CL CL = (p +/- 3rm) 27

Warning limit = WL WL = (p +/-2c,)

Experimental sigma (all laboratories) =s N

(49345-)2 162639133-15 -

14 s, = 149 pCi/liter Grand Average GA N

GA = i=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' =-- GA

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

ND'

-170 206,1 ND' = -0.8 28

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