ML080640812
| ML080640812 | |
| Person / Time | |
|---|---|
| Site: | North Carolina State University |
| Issue date: | 02/28/2008 |
| From: | Cook A North Carolina State University |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML080640812 (38) | |
Text
North Carolina State University is a land-grant university and a constituent institution of The University of North Carolina Nuclear Reactor Program I NC STATE UNIVERSITY I Department of Nuclear Engineering Campus Box 7909 Raleigh, NC 27695-7909 919.515.2321 919.513.1276 (taxl URL: www.ne.ncsu.edu/NRP reactor.
program.html February 28, 2008 TO:
Nuclear Regulatory Commission Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 RE:
NCSU PULSTAR Annual Report License No. R-120 Docket No. 50-297 In compliance with section 6.7.4 of the North Carolina State University PULSTAR Technical Specifications, our Nuclear Reactor Program staff has prepared the attached Annual Report for the period 01 January 07 - 31 December 2007.
If you have any question please feel free to contact me at (919) 515-4602 or Gerald Wicks at (919) 515-4601.
Sincerely, Andrew Cook Associate Director Nuclear Reactor Program AJIZA 4-
NORTH CAROLINA STATE UNIVERSITY DEPARTMENT OF NUCLEAR ENGINEERING PULSTAR REACTOR ANNUAL REPORT DOCKET NUMBER 50-297 For the Period: 01 January 2007 - 31 December 2007 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.
- 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 1 of 6
Textiles Water 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 ýphases of operation and supporting documents were in compliance.
Net loss of primary water from the reactor pool was detectable in early 2007 and returned to normal, non-detectable levels by the end of 2007. Health physics surveillance of reactor primary coolant water showed no fission products and that activity is below 1 0CFR20, Appendix B, Table 3 limits for all of 2007.
6.7.4.b Total Energy Output:
30.5 Megawatt.days in 2007 Reactor was Critical:
931.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> in 2007 Cumulative Total Energy Output Since Initial Criticality:
1145.4 Megawatt-days 6.7.4.c Number of Emergency and Unscheduled Shutdowns:
Emergency Shutdowns - none Unscheduled Shutdowns - FOUR
- 1.
10-JAN Reactor SCRAM on Linear Channel Overpower during fuel movement. Fuel assembly was moved to close to Linear Channel Ion Chamber. No overpower condition existed.
- 2.
01-JUN Reactor SCRAM on Linear Channel Overpower due to electronic noise. No overpower condition existed.
- 3.
04-SEPT Reactor SCRAM on Safety Channel Overpower due to operator inadvertently adjusting wrong potentiometer. No overpower condition existed.
- 4.
20SEPT Reactor SCRAM on Linear Channel Overpower due to channel not auto-ranging appropriately, which can happen on short reactor periods.
6.7.4.d Corrective and Preventative Maintenance:
Preventative maintenance, tests and calibrations are scheduled, performed and tracked utilizing thePULSTAR Surveillance File System. Each major component of the Reactor Safety System 2 of 6
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.
0739 - PS-4-06 Pool Liner - Net loss of primary water from the reactor pool was detected in early.2007. A contractor performed acoustic emission testing on the pool liner and noted one suspect location. Nuclear grade epoxy was purchase to seal the leak. Prior to applying the epoxy, water net water loss returned to normal (non-detectable) levels.
0747 - PS-6-06-2A - Stack Gas Monitor - The Stack Gas GM failed and was replaced and calibrated prior to being placed back in service. The Auxiliary GM was used for monitoring gas effluent while the Stack Gas GM was out of service.
0748 - PS-I Temperature RTD T3 - The T3 RTD transmitter failed." The RTD monitoring the water temperature returning to the pool and is not required by Technical Specifications. The transmitter was repaired, calibrated and placed back in service.
0749 - PS-1 1 - Nitrogen 16 Channel - The N-1 6 Channel ion chamber was replaced due to flooding in the valve pit area. The channel was calibrated prior to reactor operations.
0750 - PS-7-02-1 -,Auxiliary Generator - Due to interruption in the natural gas supply to the Reactor Building, a portable diesel generator was connected to Auxiliary Distribution Panel.
Appropriate tests were performed prior to reactor operations. Upon restoration of the natural gas supply, the Auxiliary Generator was reconnected and tested.
0751 - PS-1-09-1A - SCRAM Logic Unit - Front panel which displays magnet current failed.
Meter was replaced and magnet current readings verified with calibrated digital multimeter.
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:
656 - Pneumatic Transfer System Modification - To accommodate placement of shielding walls for the Positron Facility the Pneumatic Transfer System (PN) was rerouted inside the Reactor Bay. In addition,.the Reactor Bay station was removed.
658 - Electrical Distribution Modification - To accommodate power requirements of equipment necessary for the Ultra Cold Neutron Facility (UCN) the electrical distribution system was upgraded and ampacity increased.
662 - Primary Demineralizer Relocation - The Primary Demineralizer which filters and purifies the Primary System was relocated from the Mechanical Equipment Room to the Primary Piping Vault. This was done to reduce radiation exposure to personnel working in the Mechanical Equipment Room.
Document Changes Procedure changes were reviewed to determine whether or not a 1 OCFR50.59 evaluation was required. Based on the reviews, none required a 10CFR50.59 evaluation.
661 - Procedure PS 6-14-1A Liquid Waste System Test Rev. 1 - This procedure provides directions for testing the Liquid Waste System. The test was updated to reflect equipment 3 of 6
changes and expanded to include testing of drain lines.
665 - Procedure PS 6-06-4A Stack Gas Ar-41 Sensitivity Verification Rev.2 - The procedure was revised to provide directions for testing the stack gas radiation monitoring channel using existing equipment with a new test configuration and counting procedure.
668 - Procedure PS 6-16-1 :M/A Assessment of Airborne Effluent Rev.2 - The procedure was revised to correct dispersion parameters used in dose assessment.
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:
654 - Helium Liquefier Installation - A liquid helium refrigerator system was installed in the Mechanical Equipment Room. This system will provide the required cooling needed for the Ultra Cold Neutron Facility, which is currently in the design stage. The change allows for only the installation, testing and production of liquid helium and does not allow for the interaction with the reactor or any equipment associated with the reactor.
657 - Installation of a Positron Facility at the PULSTAR Reactor - The second generation Positron Facility was installed which replaced the Prototype Positron Facility (582).
Other Changes 659 - License Amendment 17 was submitted to the Nuclear Regulatory Commission in February, 2007 and under review by the U.S. Nuclear Regulatory Commission. Major changes proposed in Amendment 17 include changes to radiation monitor setpoints, fueled experiments, and organization and review committees.
6.7.4.f Radioactive Effluent:
Liquid Waste (summarized by quarters)
- i.
Radioactivity Released During the Reporting Period:
(1)
(2)
(3)
(4)1 (5)
Period Number of Total Total Diluent Tritium Batches
ýtCi Liters Liters pCi 01 JAN-31 MAR07 2
110 5.8E3 2.3E5 86 01 APR-30 JUN 07 1
36 2.6 E3 1.3 E4 34 01 JUL-30 SEP 07 1
60 3.1 E3 8.1 E4 52 01 OCT-31 DEC 07 0
0 0
0 0
2007 172 pCi of tritium was released during this year.
2007 206 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 (1) 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.
4 of 6
iii.
Disposition of Liquid Effluent not Releasable to Sanitary Sewer System:
All liquid effluent met the requirements of 1 0CFR20 for release to the sanitary sewer.
Gaseous Waste (summarized monthly)
- i.
Radioactivity Discharged During the Reporting Period (in Curies) for:
(1)
Gases:
Year Month Total Time Curies Hours 2007 JANUARY 744 0.085 FEBRUARY 696 0.329 MARCH 744 0.214 APRIL 720 0.123 MAY 744 0.248 JUNE 720 0.336 JULY 744 0.203 AUGUST 744 0.189 SEPTEMBER 720 0.304 OCTOBER 744 0.451 NOVEMBER 720 0.340 DECEMBER 744 0.309 TOTAL 8760 3.131 (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 3.131 curies in 2007.
The yearly average concentration of argon-41 released from the PULSTAR reactor facility exhaust stack in 2007 was 1.1Xl107 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 1 OCFR20 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.
5 of 6
Solid Waste from Reactor1 Total Volume of Solid Waste Packaged 26 ft3 of dry uncompacted waste.
22.5 ft3 of dries ion exchange resins.
ii.
Total Activity Involved 1.25 mCi of dry uncompacted waste.
0.5 mCi of dry ion exchange resins.
iii.
Dates of shipments and disposal Transfers to the university broad scope radioactive materials license were made on 6 March 2007, 19 July 2007,.and 14 December 2007. The University Environmental Health and Safety Center arranges disposal of hazardous wastes.
6.7.4.g Personnel Radiation Exposure Report:
25 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 2007 to 31 Dec 2007 was 2.064 person-rem. Individual deep dose-equivalent ranged from 0 to 0.227 rem with an average of 0.083 rem. No visitors required official radiation dose monitoring during 2007.
6.7.4.h Summary of Radiation and Contamination Surveys 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 Centerat the end of this document for results of environmental sampling andanalysis.
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 pIrem/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.
6 of 6
ATTACHMENT A PULSTAR REACTOR ENVIRONMENTAL RADIATION SURVEILLANCE REPORT FOR THE PERIOD JANUARY 1, 2007 - DECEMBER 31, 2007 NORTH CAROLINA STATEUNIVERSITY ENVIRONMENTAL HEALTH AND SAFETY CENTER RADIATION SAFETY DIVISION by Ralton J. Harris Environmental Health Physicist
TABLE OF CONTENTS
- 1.
INTRODUCTION Table 1 Environmental Monitoring Programs for the PULSTAR Reactor
- 2.
AIR MONITORING Tabie 2.1 Location of Air Monitoring Stations Table 2.2 Aerially Transported Gamma Activity (LLD Values)
Figures 2a-2e Airborne Gross Beta Activities Table 2.3 Regulatory Limits, Alert Levels and Background Levels for Airborne Radioactivity
- 3.
MILK Table 3.1 1-131 in Cow' s Milk
- 4.
SURFACE WATER, Table 4.1 Gross Alpha and Beta Activity in Surface Water Table 4.2 LLD Values for Gamma Emitters in Surface Water
- 5.
VEGETATION Table 5.1 Gross Beta Activity in Campus Vegetation Table 5.2 LLD Values for Gamma Emitters in Vegetation
- 6.
THERMOLUMINESCENT DOSIMETERS Table 6.1 Environmental TLD Exposures
- 7.
QUALITY CONTROL INTERCOMPARISON PROGRAM Tables 7.1 a - 7.1 d
- 8.
CONCLUSIONS APPENDIX 1 APPENDIX 2 PAGE NO.
1 2
3 3
4 5-9 10 11 12 13 14 15 16 17 18 19 - 22 23 24 - 28 29
- 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 coniindually for one week during each of four (4) quarters during the year. The data shows the normal fluctuations in I 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 31.1 fCiM 3 at the D.H. Hill Library station during the week of 05/14/07 to 05/21/07. The annual campus average was 17.3 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 radiornuclides 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
ýSITE
'BROUGHTON LIBRARY DANIELS WITHERS EH & S CENTER NORTH HALL DIRECTION1 SOUTHWEST NORTHWEST SOUTHEAST NORTHEAST WEST NORTHEAST DISTANCE 2 (meters) 125 192 90 82 1230 402 ELEVATION 3 (meters)
-17
'*+11
-8
-6
'-3
-4 1DIRECTION - DIRECTION FROM REACTOR STACK 2DISTANCE - DISTANCE FROM REACTOR STACK 3ELEVATION - ELEVATION RELATIVE TO THE TOP OF. THE REACTOR STACK A wind rose is included in' Appendix 2 to indicate the prevailing wind direction trends for the years 2000-2006.
3
Table 2.2 Aerially Transported Gamma Activity JLLD values fCi/cubic meter I _
-I___
I I________
I INUCLIDES tI I
_____ 1
__I__
SAMPLING PERIOD 1 Co-57
_Co-60_
Nb-95 Zr-95 Ru-103 Ru-106 Cs-137 I Ce-141 C8144
.2007 02/16-02/23 0.21 0.35 10.29 0.47 0.27 L 2.37 0.26 0.38 1.22 05/14-05/21 1
0.2 I
0.37 0.28 0.48 0.28 2.48 T 0.29 0.34 1.28
-09/05-09/12 0.18 0.35 10.31 j
0.54 0.33
[ 2.51
{ 0.29 0.43 1.40 11/13-11/20 1 0.17 0.37 0.37 0.50 G 0.32 L 2.41 1
0.29 1
0.39 1.41
25 20
-Broughton Hall.
Airborne Gross Beta Activity Figure 2a Q~
E
.2 15 10
[I-5 0
-H 1
2 3
4 Quarters per Year
Withers Hall 25 Airborne Gross Beta Activity Fi ure 2b 20 15
- lO/
5 0
1 2
3 4
Quarters per Year
25 20
~15 E
U.
~10 i5 0
Daniels Hall Airborne Gross Beta Figure 2c 2
3 4
Quarters per Year
D.H. Hill Library Airborne Gross Beta Activity Figure 2d 30 25 20 E
C.2
° 15 0*
10 5
0 12 3
4 Quarters per Year
Environmental Health & Safety Center Airborne Gross Beta Activity Figure 2e 25 20 15 E
G 0
'4-5 0
12 3
4 Quarters per Year
TABLE 2.3 REGULATORY LIMITS, ALERT LEVELS, AND BACKGROUND LEVELS FOR AIRBORNE RADIOACTIVITY (fCi M73).
REGULATORY LIMIT ALERT LEVEL AVERAGE N.C.
BACKGROUND LEVEL NUCLIDE GROSS ALPHA GROSS BETA*
Cs-137 Ce-144 Ru-1 06 1-131 20 10 4
1000 5 X 105 2 X 10' 2X 105 1 X 105 500 3.3 - 13.9*
10 100 2
0 0
0 30 10
- 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.
10
- 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 the year 2007 shows that no 1-131 activity was detected. The next sample collection will be in 2009.
TABLE 3.1A 1-131 IN COW' S MILK (pCi Liter"1 2 oF) LLD -
3 pCi Liter-pCi Liter-1 DATE Campus Creamery Lake Wheeler May 2007
<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 Liter1 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 Table 4.2 were detected.
TABLE 4.1 GROSS ALPHA AND BETA ACTIVITY IN SURFACE WATER (pCi Liter
+/- 2a)
- LLD,- 0.4 pCi Liter1 LLDp - 0.4 pCi Liter -'
pCi Liter-1 GROSS ALPHA GROSS BETA DATE LOCATION FIRST QUARTER 2007 SECOND QUARTER 2007 THIRD QUARTER 2,007 FOURTH QUARTER 2007 ON OFF ON OFF ON OFF ON OFF
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4 3.0 +/- 0.7 2.6 +/- 0.7 3.2 +/- 0.7 3.0 +/- 0.7 3.3+0.7 2.6+0.7 3.4 + 0.7 3.1 +0.7 12
TABLE 4.2 LLD VALUES FOR GAMMA EMITTERS IN SURFACE WATER NUCLIDE LLD (pCi Liter1)
Co-60 0.4
- 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. The next sample collection will be in 2009.
TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION
- LLD - 0.5 pCi g-1 SAMPLE DATE 09/28/2007 09/28/2007 09/28/2007 09/28/2007 SAMPLE LOCATION NORTH CAMPUS SOUTH CAMPUS EAST CAMPUS WEST CAMPUS (P..q-g1 +/- 2a) 9.7 +/-0.4 9.6 +/-0.5 3.5 +/-0.4 5.7 +/-0.4 14
TABLE 5.2 LLD VALUES FOR GAMMA EMITTERS IN VEGETATION NUCLIDE Co-60 Zn-65 Cs-137 Cs-134 Sr-85 Ru-103 Nb-95 Zr-95 LLD (pCi gram-).
0.01 0.02 0.01 0.01 0.01 0.01 0.01 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.
16
TABLE 6.1 I ENVIRONMENTAL TLD EXPOSURES (mrem/QUARTER YEAR)
DATE IWlTHERSIDANIELS IBROUGHTON IDH HILL*.EH&S PULSTAR 2007 8
6__
01/01-03/31 8
2 6
28,24,25 15 31 I
04/01-06/301 M
5 3
4,3,5 4
29 07/01-09/30 2
7 10 7,6,6 11 34 10/01-12/31 3
9 3
4,8,5 5
33
- The entries for D.H. Hill are for three (3) independent dosimeter readings for that station.
NORTH COI'N 3
M,1 2
M,4 5
M,6 8
[M,8 JTROL I
-1 The "CONTROL" column indicates the use of dual control dosimeters for all the monitoring periods.
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 All values reported are Deep DDE I
I F.
- 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 Session17) 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 = (i 00)(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%
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.
18
TABLE 7.1a GROSS ALPHA & BETA ACTIVITY AIR FILTER--INTERCOMPARISON STUDY 01 January 2007 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 Gross Alpha Gross Beta
- Reported Value
- Reported Error MAPEP Value Acceptance Range
>0.0 - 1.202 0.221 - 0.622 0.308 0.432 0.033 0.022 0.601 0.441 19
TABLE 7.1b MULTINUCLIDE AIR FILTER,' INTERCOMPARISON STUDY 01 January 2007 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 2.781 0.054 2.9054 2.0338 - 3.7770 Csl 37 2.378 0.063 2.5693 1.7985 - 3.3401 Cs134 2.849 0.048 4.1960 2.9372 - 5.4548 Co57 2.951 0.059 2.8867 2.0213 - 3.7539 Mn54 3.496 0.095 3.5185 2.4630 - 4.5741 Zn65 2.564 0.091 2.6828 1.8780 - 3.4876 20
TABLE 7.1c MULTINUCLIDE WATER SAMPLE - INTERCOMPARISON STUDY 01 January 2007 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 27.07 0.64 26.9 18.8 - 35.0 Cs137 187.11 5.77 163.0 114.1 - 211.9 Cs134 81.64 1.64 83.5 58.5 - 108.6 Co57 149.42 4.50 143.7 100.6 - 186.8 Mn54 136.26 4.29 123.8 86.7 - 160.9 Zn65 120.23 3.55 114.8 80.4-149.2 21
TABLE 7.1d GROSS ALPHA AND BETA WATER SAMPLE - INTERCOMPARISON STUDY 01 January 2007 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 Gross Alpha Gross Beta
- Reported Value
- Reported Error MAPEP Acceptance Value Range 0.327
> 0.0 - 0.654 0.851 0.426 - 1.277 0.497 0.628 0.129 0.108 22
. I 1 1, ' I i I
! F7 'ý",, -T,,, I
- 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, prirmordial 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.
23
APPENDIX 1 The following example calculation gives a set of data, the mean value, the experimental sigma, and the range. These statistics provide measui-es 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, (R.
The normalized range measures the dispersion of the data (precision) in such a form that contrel 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 iscalcuiated 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 3H/Liter on September 24, 1974 Expected laboratory precision =
= 357 pCi/liter Sample Result X1 3060 pCi/liter X2 3060 pCi/liter X3 3240 pCi/liter Mean = x
- X, 9360 x
3 3120 pCi/liter N
where N = number of results = 3 Experimental sigma = s N
X N
s (X
2-X 1
)
='
i_
N N-I (3060)2+(3060 2+ (3240)2_ (3060+3060+3240)2 3
S 2
s
=
103.9 pCi/liter Range
=
r r
=
lmaximum result - minimum result I r
=
13240 - 30601 r
=
180 pCi/liter 25
Range Analysis (RNG ANLY)*
Mean range R
d" a 2 ~
where d2** = 1.693 for N = 3 R
Control limit CL
=
(1.693) (357)
=
604.4 pCi/liter
=
CL
= R + 3aR
= D4R where D4** = 2.575 for N = 3
=
(2.575) (604.4)
=
1556 pCi/liter CL Standard error of the range
=
CYR
=
(R+3oR-R)+ 3 (D4R -R) + 3
=
(1556-604.4) 3 aR
=
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 + xqR r-R or therefore w+x = 1 +x
= 1 +
r -
- Rosentein, M., and A. S. Goldin, "Statistical Techniques for Quality Control of Environmental Radioassay,"
AQCS Report Stat-i, 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 = WRR+XoR = wR or W --
r therefore w +x =w
+0 R
since r < R, (180 < 604.4) 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 =--p
= 3120 - 3273 D = -153 pCi/liter Standard error of the mean =om a
(Crn -
V/N 357 V/3 a=
206.1 pCi/liter D
ND-Oam
-153 206.1 ND = -0.7 Control limit = CL CL = (p +/-3m) 27
Warning limit = WL WL= (pl+/-2om)
Experimental sigma (all laboratories) =s N
/*X.2-i=1 St N1 S 4 -
162639133 -
(49345 )2
=
15 14 s,
= 149 pCi/liter Grand Average = GA 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'
- GA
= 3120 - 3290 D'= -170 pCi/liter ND'
=
-170 206.1 ND
= -0.8 28
APPENDIX 2 Joint Frequency Distribution Raleigh Durham Airport: 2000 - 2007 N
15.07 W
E S
0.1 3.5 6.9 11.5 18.4 24.2, Wind Speed ( Miles Per Hour)
Calms excluded.
Rings drawn at, 5% intervals.
Wind flow is FROM the directions shown.
1025 observations were missing.
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