ML20117E888

Pulstar Reactor Annual Report to NRC for Jul 1995 - June 1996

ML20117E888
Person / Time
Site:	North Carolina State University
Issue date:	06/30/1996
From:	Dudziak D, Mayo C, Perez P North Carolina State University, RALEIGH, NC
To:
References
NUDOCS 9609030152
Download: ML20117E888 (40)

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North Carolina State University J

Nuclear Reactor Program )

Department of Nuclear Engineering l Box 7909 Italcigh, NC 27695 7909 (919) 515 2321 FAX (919) 515 5115 26 August 1996 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Subject:

NCSU PULSTAR Annual Report Docket No. 50-297

Dear Sir:

In compliance with Section 6.7.5 of the North Carolina State University PULSTAR Technical Specifications, our Nuclear Reactor Program staff has prepared the attached Annual Report for the period 01 July 1995 through 30 June 1996. Please feel free to contact Mr. Perez at (919) 515-4602 if you have any questions or comments.

Sincerely, l Pedro B. Perez k

Associate Director Nuclear Reactor Program i

C [d W p in [ .. ~

Charles W. Mayo Donalld J. Dudziak ' l Director, Nuclear Reactor Program Head, Department of Nuclear Engineering I l

PDP/CWM:sb copy w/ attachments:

Mr. Stewart D.13bneter, Administrator Mr. Stephen J. Dilyj U. S. Nuclear Regulatory Commission, Region 11 Reactor Operations Manager l Dr. David J. DeMaster, Chairman Mr. David Rainer, Director Radiation Protection Committee Environmental IIcalth and Safety Center

Dr. Charles W. Mayo, Chairman Dr. II. Merrick llarriscm Reactor Safety and Audit Committee Radiation Protection Ofreer l

Dr. Nino A. Masnari, Dean Mr. Mark Poirier College of Engineering ANI/MAELU

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9609030152 960630 / i PDR ADOCK 05000297 1 R PDR I l

North Carolina State Unit'ersity is a land-grant university and a constituent institution of The University of North Carolir a.

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PULSTAR REACTOR ANNUAL REPORT TO l l

UNITED STATES NUCLEAR REGULATORY COMMISSION for 01 July 1995 - 30 June 19%

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NCSU NUCLEAR REACTOR PROGRAM 26 August 1996 )

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Reference:

PULSTAR Technical Specifications Section 6.7.5 Docket No. 50-297 Department of Nuclear Engineering North Carolina State University Raleigh, North Carolina 27695

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l DEPARTMENT OF NUCL. EAR ENGINEERING PULSTAR REACTOR ANNUAL REPORT l DOCKET NUMBER 50-297 For the Period: 01 July 1995 - 30 June 1996 The following report is submitted in accordance with Section 6.7.5 of the PULSTAR Technical Specificationc-6.7.5.a Brief Summan Reactor operations have been routine during this reporting period. With the exception of an auto-ranging circuit malfunction in the new Linear Power Monitor, there have not been any unexpected maintenance or operational problems.

(1) Reactor Operating Experience:

The NCSU PULSTAR Reactor has been utilized for the following:

a. Teaching and Short Courses 66.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />

b. Faculty and Graduate Student Research 213.1

c. Isotope Production 51.4  ;

d. Neutron Activation Analysis 886.0  ;

c. Beam Tube Facilities 0.0

f. Nuclear Training (Utilities) 43.6

g. PULSTAR Reactor Training 4.9

h. Reactor Cal / Measurements & Surveillance 49.2

i. Reactor Health Physics Surveillance 6.5

j. Reactor Sharing 0.0 TOTAL 1,320.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Same reporting period 1994-1995 1,526.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />

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PUISTAR REACIDR ANNUAL RIToRT 2

, DOCKLT NUMIAER 50-297 i i

01 July 1995 30 June 1996 j

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A cross section of experiments performed in the reaclan l

a. Reactor thermal power measurements for teaching laboratories.  :

b. Neutron temperature measurements for teaching laboratories.

c. Neutron diffusion length in graphite for teaching laboratories.

d. Neutron Activation Analysis of filters, tissue, sediments / soil, rain / river water, vegetation, wood pulp, fibers, resins, ceramics, coal, fly ash, tar, oil residue, and graphite.

c. Prompt gamma analysis of boron.

f. Neutron fluence and spectral measurements.

g. Transmutation of silicon for semiconductor research.

(2) Changes in Performance Characteristics Related to Reactor Safety: r None (3) Results of Surveillance. Tests. and Inspections:

The reactor surveillance program has revealed no significant or unexpected trends in reactor systems performance during this report  :

period. The annual facility and records inspection was determined to be l satisfactory by the Reactor Safety and Audit Committee.

i 6.7.5.b Total Enerev Output:

l 4733 Megawatt hours 19.7 Megawatt days i Pulse Operations:

None Reactor was Critical:

573.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> Cumulative Total Enerev Output Since Initial Criticality:

19,417.2 Megawatt hours 809.1 Megawatt days l

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e PUISTAR REACroR ANNUAL REPORT 3 l t DOCKLT NUMBER 50 297 1

01 July 1995 - 30 June 1996 i

6.7.5.c Number of Emergency and Unscheduled Shutdowns:

(1) Unscheduled Shutdowns - 3 total

a. Linear Channel auto-rrutging failure - 2

b. Secondary cooling pipes froze (2) Inadvertent SCRAMS - 1 total

a. Loss of 24 VAC bus Explanation of (1)a. above:

The newly installed Linear Power Monitor in the Linear Channel failed to automatically range during a startup. The reactor operator terminated the l

power increase and shut down the reactor. After performing calibrations, the reactor was restarted and the monitor failed in the same manner. The monitor  !

was returned to the manufacturer for repair. As of this report the monitor has <

not been returned. The original Linear Picoammeter was re-installed and reactor operations were resumed.  !

l Explanation of (1)b. above:

The unusually cold winter caused secondary water in a vertical section of pipe adjacent to the cooling tower to freeze. When primary heat could no longer be rejected, the reactor was shut down. Reactor operations resumed after the pipe was thawed.

l Explanation of (2)a. above:

l Insulation on a 24 VAC control wire, which is normally flexed as the instrument is racked in and out of the console for calibration, was abraded to the point that the conductor momentarily shorted to ground blowing the

24 VAC bus fuse. The abraded area was repaired and similar wires on other l instruments were subsequently inspected. Additionally, a " spiral wrap" protective covering was added to the wires that are flexed.

6.7.5.d Major Maintenance Operations:

None

FUISTAR REACIDR ANNUAL REPORT 4 j

, DoCKI?T NUMBER 50-297 01 July 1995 30 June 1996 6.7.5.e Changes in Facility. Procedures. Tests. and Experiments:

1. Design Changes

a. DC 95-2 authorized the replacement of the Source Range and Unear '

Power Monitor chart recorders.

b. DC 95-3 installed an additional SCRAM circuit to monitor primary coolant temperature and automatically shut off primary pump when pool water level drops to the Safety System Setting. It also included  :

Revision 14 to the PULSTAR Operations Manual.

c. DC 96-1 authorized the re-installation of the original Linear Picoammeter in the console while the new Linear Power Monitor is being repaired by the manufacturer.

2. Procedure Changes ,

a. PC 17-95 was Revision 15 to the PULSTAR Operations Manual. This document addressed the procedural differences required by the newly >

installed nuclear instruments. It also implemented the most recent' ,

revision to the PULSTAR Emergency Plan.

b. PC 18-95 was Revision 16 to the PULSTAR Operations Manual. This document incorporated commitments to the NRC concerning procedure for abnormal equipment behavior and clarified the Startup Chec).mt Procedure.

c. PC 8-96 was Revision 17 to the PULSTAR Operations Manual. This document addressed procedural differences required to re-install the original Linear Picoammeter while the new Linear Power Monitor is ,

being repaired.

d. A total of thirty-four procedures were written or revised covering the calibration of newly installed equipment described in (1) above, reactor operations, and ten Health Physics procedures. These procedures have been reviewed and/or approved by the Reactor Safety and Audit Committee (RSAC) and the Radiation Protection Committee (RPC). f 1

I PULSTAR RIMCIOR ANNUAL REPORT 5

• DOCKLT NUMBER 50-297 i

01 July 1995 30 June 1996 6.7.5.f Radioactive Effluent: ,

i l l A. Liauid Waste (summarized by quarters) l l

l 1. Radioactivity Released During the Reporting Period:

l l (a) (b) (c) (d)' (e) )

l No. of Total Tot. Vol. Diluent Tritium Period Batches Ci Liters Uters Ci 01 Jul - 30 Sep 95 2 53 6.8E3 2.2E5 30 j 01 Oct - 31 Dec 95 3 47 1.0E4 2.7E5 19 l 01 Jan - 31 Mar 96 0 0 0 0 0 1 01 Apr - 30 Jun 96 1 16 2.7E3 1.0E4 15 l

(f) 116 Ci total activity released during this reporting period.

(g) 64 pCi of tritium were released during this reporting period.

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2. Identification of Fission and Activation Products: 1 The gross beta-gamma activity of the batches in (a) above were less than 2 x 10-5 Ci/ml. Isotopic analyses of these batches indicated low levels of typical corrosion and activation products. No fission products were detected.

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

All liquid effluent were released to the sanitary sewer. Radioactivity and concentrations were within 10 CFR 20 limits when diluted by the minimum daily campus discharge of 2.8E6 liters. Solubility tests were performed for all discharges made after 01 January 1996 as discussed in USNRC Information Notice 94-07.

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

PUISTAR REACTOR ANNUAL REPORT 6

, IXXXEr NUMBER 50 297 01 July 1995 30 June 1996 B. Gaseous Waste (summarized monthly)

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

(a) Gases:

Total Time

_ Year Period In Hours Curies 1995 01 Jul - 31 Jul 744 0.107 01 Aug - 31 Aug 744 0.264 01 Sep - 30 Sep 720 0319 01 Oct - 31 Oct 744 0.295 01 Nov - 30 Nov 720 0.158 01 Dec - 31 Dec 744 0.0 1996 01 Jan - 31 Jan 744 0.240 01 Feb - 29 Feb 696 0.325 01 Mar - 31 Mar 744 0.318 01 Apr - 30 Apr 720 0.168 01 May - 31 May 744 0.071 01 Jun - 30 Jun 720 0.062 Totals 8,784 2.327 (b)' Particulates with a half-life of greater than eight days:

Filters from the particulate monitoring channel were analyzed upon removal. There was no particulate activity indicated on any filter during this reporting period.

2. Gases and Particulates Discharged During the Reporting Period:

(a) Gases:

Total activity of argon-41 release was 2.327 curies.

The yearly average concentration of argon-41 released from the PULSTAR reactor facility exhaust stack during this period was 6.93 x 10-' Ci/cc. This is below the regulatory limit of 1 x 10 Ci/cc. (10 CFR 20 Appendix B)

(b) Particulates:

See gaseous waste 1.(b) above.

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PUl5rAR REACIDR ANNUAL REPORT 7

, Domtrr NUMBER 50-297 l 01 July 1995 30 June 1996 '

C. Solid Waste from Reactor 2

1. Total volume of solid waste - 57.5 ft' (1.63 m') l l

• ' Total activity of solid waste - 1.% mci

3. Dates of shipments and disposal:

All waste is in storage at the NCSU Environmental Health and Safety Center disposal facility.

6.7.5.g Personnel Radiation Exoosure Reoort Twenty-six members of the faculty and staff were monitored for external radiation exposure during the reporting period. Two of the twenty-six received measurable exposure which ranged from 0.01 to 0.02 rem. Total person-rem for the faculty and staff was 0.03.

Approximately 20 film badges were issued to graduate students, temporary staff, short course participants, and visitors. Radiation exposures ranged to 0.03 rem. The majority of these exposures were in the "no measurable exposure" range.

6.7.5.h Summarv of Rad ation and Contamination Surveys Within the Facility Radiation and contamination surveys performed within the facility by the PULSTAR staff indicated that:

• external radiation levels in the majority of areas were <2 mrem /h

• contamination levels in most areas were not detectable

= when contamination was detected, the area or item was confined or decontaminated

• external radiation levels in the remaining areas were as expected due to reactor operations f

i 2 Due to the failure of North Carolina to license a low level radioactive waste site, solid waste generated at the PULSTAR Reactor can no longer be shipped for burial and must l be stored on campus. A total of 44.1 ft' (1.25 m') of spent resins with an activity of 1.31 mci from previous years of operation were de-watered and processed for future land burial or incineration. The remaining solid waste is composed of compacted trash, debris, and sources / samples that are no longer useful.

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l PUL5fAR REACTOR ANNUAL RIToRT g o DOCKET NUMBER 50 297 01 July 1995 30 June 1996 6.7.5.i Description of Environmental Surveys Outside of the Facility See Attachment A prepared by the Radiation Protection Division of the Department of Environmental Health and Safety.

Perimeter surveys were performed adjacent to the Reactor Building by the l

PULSTAR staff and indicated that:

• external radiation levels were at background levels for most areas (10 rem /h)

• contamination levels were not detectable

• Net external radiation levels ranged up to 20 rem /h in some areas when the reactor was operating at power. However, external radiation levels were at background levels in routinely occupied spaces.

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ATTACHMENT A NORTH CAROLINA STATE UNIVERSITY i

DEPARTMENT OF ENVIRONMENTAL HEALTH AND SAFETY RADIATION PROTECTION DIVISION ENVIRONMENTAL RADIATION SURVEILLANCE REPORT FOR THE PERIOD l JULY 1,1995 - JUNE 30,1996 l

RALTON J. HARRIS AND JOY L. DOUGLASS i

i TABLE OF CONTENTS ,

PAGE NO.

1. INTRODUCTION 1  ;

Table 1 Current and Projected Environmental Monitoring 2

2. AIR MONITORING 3 Table 2.1 Location of Air Monitoring Stations 3 Figures 2a-2f Airbome Gross Beta Activities 4-9 Table 2.2 Aerially Transported Gamma Activity (LLD Values) 10 Table 2.3 Regulatory Limits, Alert Levels and Background Levels for Airborne Radioactivity 11

3. MILK Table 3.1 12

4. SURFACE WATER Table 4.1 Gross Alpha and Beta Activity in Surface Water 13 Table 4.2 LLD Values for Gamma Emitters in Surface Water 14

5. VEGETATION Table 5.1 Gross Beta Activity in Campus Vegetation 15 Table 5.2 LLD Values for Gamma Emitters in Vegetation 16

6. THERMOLUMINESCENT DOSIMETERS 17 Table 6.1 Environmental TLD Exposures 18

7. QUALITY CONTROL INTERCOMPARISON PROGRAM 19 Tables 7.1a - 7.1c 20 - 22

8. CONCLUSIONS 23 i

9. ACKNOWLEDGMENTS 23 APPENDIX 1 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.

During 1995, the Director of the Environmental Health and Safety Center created )

a committee to assess the environmental monitoring program for the PULSTAR Reactor. This committee issued a detailed report entitled " Report of the i Committee to Assess the Environmental Monitoring Program for the North l Carolina State PULSTAR Reactor" in which several recommendations were l proposed regarding modifications to this program. This information is i summarized in Table 1 which has been excerpted from the committee's report.

In brief, the committee recommended the following changes:

1) Discontinue the monthly milk sampling, but instead collect and analyze l one milk sample in alternate years. '

2) Discontinue the semi-annual vegetation collection, but instead collect and analyze one vegetation sample in alternate years.

3) Change the frequency of air sampling from continuous sampling with filters being collected each week (7-day cycle) to a periodic sampling mode in which air samplers are operated for only one week (7 days) during each 3 month period of the year.

4) Move the air sampler at David Clark Labs to the Environmental Health and Safety Center.

5) Move the air sampler at Withers Hall to North Hall (a student dormitory).

At the present date of this report, all the recommended changes have been implemented with the exception of Number 5. The Physical Plant Division of NCSU has expressed a concern about potential damage to the rubber-lined roof 1

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of North Hall which may result if the air sampling station is located at that site.

This issue has not been resolved as yet. In an attempt to achieve partial compliance with the committee's recommendations, a TLD station has been located at North Hall to monitor environmental gamma radiation levels.

, Table 1:

Current and Projected Environmental Monitoring Programs for the PULSTAR l Reactor at North Carolina State University l

Sample Activity Conducted Frequency Recommended Basis For Measured By Change Measurement Stack Gases Gross Gamma N.E. Continuuus None 10 CFR 20 T.S. 6.7.5 l Stack Particles Gross Beta N.E. Monthly None 10 CFR 20 i indiv. Gamma N.E. T.S. 6.7.5 Emitters i

Water from Gross Beta N.E. Prior to None 10 CFR 20 )

Reactor Facility Gross Gamma N.E. Discharge T.S. 6.7.5 Tritium N.E. (~ Monthly) City of Raleigh Ordinance

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Air / Particles at Gross Beta RPO/EHSC Weekly Quarterly Change 10 CFR 20 5 Campus indiv. Gamma RPO/EHSC Weekly Locations # 10 CFR 20 Stations

• Emitters  !

i Air / Dosage at 7 TLD Dosimeter RPO/EHSC Quarterly Change Locations # t0 CFR 20 Campus Stations +

Surface Water Gross Beta RPO/EHSC Quarterly None NCSU i l Rocky Branch Indiv. Gamma RPO/EHSC Quarterly None NCSU i Creek Emitters Vegetation Gross Beta RPO/EHSC Semi-annually Discontinue NCSU NCSU Campus Gamma RPO/EHSC Discontinue NCSU Milk l-131 RPO/EHSC Monthly Discontinue NCSU '

Local Dairy Abbreviations Used in Table:

l N.E. = Nuclear Engineering / Reactor Facility; RPO/EHSC = Radiation Protection Office.

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• These 5 stations include:

Withers, Riddick, Broughton, Hill Library and David Clark Labs.

+These 7 stations include: the PULSTAR stack, a control station (EHSC) and the 5 air sampling stations.

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

Figures 2a through 2f show bar graphs of gross beta activity (fCi/ cubic meter vs. week number). The highest gross beta activity observed was 34.4 fCim at the Broughton  :

station during the week cf 11-23-95. The annual campus average was 15.1 fCim . l Beginning in January 1996, air monitoring frequency has been changed such that air  !

sampling is performed for one week during each quarter each year. This change is l reflected in the figures 2a - 2f.  !

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.

During 1995-96, the air monitoring equipment was rebuilt and fitted with new 3/4 H.P.

electric motors and air pumps to provide a more reliable system.

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

TABLE 2.1 LOCATION OF AIR MONITORING STATIONS SlIE DIRECTION DISTANCE 2 ELEVATIONS (meters) (meters)

BROUGHTON SOUTHWEST 125 -17

• DAVID CLARK LABS WEST 500 -18 LIBRARY NORTHWEST 192 +11 l RIDDICK SOUTHEAST 99 -14 l WITHERS NORTHEAST 82 -6 EH & S CENTER WEST 1230 -3  ;

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' DIRECTION - DIRECTION FROM REACTOR STACK 2 DISTANCE - DISTANCE FROM REACTOR STACK

• ELEVATION - ELEVATION RELATIVE TO THE TOP OF THE REACTOR STACK

• The station at David Clark Labs was relocated to the EH & S Center in January 1996.  ;

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FIGURE 2f REGULATORY LIMIT =1000 fCi/M3 AIRBORNE GROSS BETA ACTIVITY ALERT LEVEL2 = 500 fCi/M l N.C. STATE UNIVERSITY CAMPUS LLD - 1 fCi/M Environmental Health & Safety Center 16 --

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WEEK NUMBER FROM JUNE 29,1995 THROUGH MAY 29,1996 JUNE 29 BEGINS AT WEEK #1 O

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TABLE 6.1 ' ENVIRONMENTAL TLD EXPOSURES (mR/ QUARTER YEAR 2s)

DATE WITHERS RIDDICK BROUGHTON LIBRARY DAVID CLARK PULSTAR STACK CONTROL 04/25/95 - 06/29/95 8.2 i 1.2 15.713.1 10.8 1.5 10.111.6 29.3133.3 3 5.5 1.2 13.911.9 06/29/95 - 10/03/95 22.7111. 26.81 2.5 20.712.3 20.1 i 1.7 i 34.3 i 18.8 21.0 i 1.2 23.4 i 1.1 10/03/95 - 01/05/96 17.410.6:23.6i4.9,18.611.5 19.811.5 20.212.7 22.0 i 1.4 20.5 i 1.0 01/05/96 - 04/03/96 18.1 i 1.1 25.4 i 1.2l 18.5 i 1.9 24.4 i 2.2 16.510.9 21.9

• 1.5 23.111.4

'04/03/96- 07/01/96 17.3 i 1.5 24.3 i 1.8' 19.3 i 1.3 2.7 i 18. 15.8 i 0.6 19.510.9 24.615.6 i

l The large error term in the exposure for David Clark Labs,29.3 t 33.3 mR, is unexplained.

! It may have been due to some fault in TLD processing. I i 1

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i o TABLE 2.3 REGULATORY LIMITS, ALERT LEVELS, AND BACKGROUND LEVELS FOR AIRBORNE RADIOACTIVITY (fCi m-)

REGULATORY ALERT- AVERAGE N.C.

NUCLIDE LIMll LEVEL BACKGROUND LEVEL GROSS ALPHA 20 10 4 GROSS BETA 1000 500 100 Cs-137 5 X 105 10 2 Ce-144 2 X 105 100 0 l

l Ru-106 2 X 105 30 0 1-131 1 X 105 10 0 l

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Reference:

Environmental Radiation Surveillance Report 1986-88, State of N.C. Radiation Protection Section l

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3. MILK (TABLE 3.1)

Milk samples are collected each month from the Campus Creamery and the Lake Wheeler Road Dairy. Previously, samples were obtained from the Randleigh Dairy Farm but it is no l longer operational. Beginning in January 1996 milk sampling schedules have been revised to l be performed in alternate years.

No 1-131 activity was detected in any of these samples.

TABLE 3.1 1-131 IN COWS' MILK (pCi liter ' i 2 c) LLD - 3 pCi liter-pCi liter' DATE CAMPUS CREAMERY LAKE WHEELER JULY 1995 s 3.0 s 3.0 AUGUST 1995 s 3.0 s 3.0 SEPTEMBER 1995 s 3.0 s 3.0 OCTOBER 1995 s 3.0 s 3.0 NOVEMBER 1995 s 3.0 s 3.0 DECEMBER 1995 s 3.0 s 3.0 i

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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 values for gross alpha and beta activities are - 0.4 pCi liter' and - 0.4 pCi liter , respectively. For gross alpha activity the Alert Level is 5 pCi liter' and the Regulatory Limit is 15 pCi liter'. For grcs:: bata activity the Alert Levelis 5 pCiliter' and the Regulatory Limit is 50 pCiliter'. Samples with gross alpha or beta activities exceeding these Alert Levels would require gamma analysis to identify the radionuclides present. The LLD values in Table 4.2 are for the second quarter of 1996.

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TABLE 4.1 GROSS ALPHA AND BETA ACTIVITY IN SURFACE WATER (pClliter i 20)

• LLDa - 0.4 pCi liter' LLDQ - 0.4 pCl liter' l

1 pCi liter' GROSS GROSS DATE LOCATION ALPHA BETA THIRD QUARTER 1995 ON < 0.4 < 0.4 OFF < 0.4 < 0.4 1

1 FOURTH QUARTER 1995 ON < 0.4 < 0.4  ;

OFF < 0.4 < 0.4 i l

FIRST QUARTER 1996 ON < 0.4 < 0.4 OFF < 0.4 < 0.4 SECOND QUARTER 1996 ON < 0.4 < 0.4 OFF < 0.4 < 0.4

• LLD VALUES ARE DETERMINED QUARTERLY l

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TABLE 4.2 LLD VALUES FOR GAMMA EMITTERS IN SURFACE WATER 1

l NUCLIDE LLD (pCi liter')*

Co-60 0.4 Zn-65 0.7 Cs-137 0.3 i

Cs-134 0.4 Sr-85 0.4 Ru-103 0.3 Ru-106 3.0 Nb-95 0.4 Zr-95 0.5

• LLD VALUES ARE FOR THE 2ND QUARTER OF 1996 l

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5. VEGETATION (TABLE 5.1 AND 5.2)

Table 5.1 gives gross beta activities for grass samples collected on the NCSU Campus. The reported activities are all below the Alert Level of 20 pCi gramd . Table 5.2 lists LLD values for i several gamma emitters. No gamma activity due to any of these radionuclides has been observed l in campus vegetation. The beta and gamma activities are reported as pCi per gram of green l vegetation. Beginning in January of 1996, the vegetation sampling has been revised to be performed in alternate years.

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l TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION

• LLD - 0.5 pCi g 4 ,

I l SAMPLE DATE SAMPLE LOCATION (DCiod f20) l DECEMBER 1995 NORTH CAMPUS 3.6 i 0.1 l

DECEMBER 1995 SOUTH CAMPUS 2.6 i 0.1 DECEMBER 1995 EAST CAMPUS 2.5 1 0.1 DECEMBER 1995 WEST CAMPUS 2.5 i 0.2 )

• LLD values are determined semiannually l l

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1 TABLE 5.2 LLD VALUES FOR GAMMA EMITTERS IN VEGETATION l

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NUCLIDE LLD (pCi gram4 )*

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

• LLD VALUES ARE FOR THE 2ND QUARTER OF 1996 l

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6. THERMOLUMINESCENT DOSIMETERS (TLDs) (TABLE 6.1)

TLD analysis is contracted to Teledyne isotopes for determination of ambient gamma exposures.

The dosimeters are CaSO4doped with dysprosium and have a manufacturer-stated sensitivity of 0.510.15 mR (90% C.L.). Exposures are integrated over a three-month period at each of the five air monitor stations listed in Table 2.1 and also at the top of the PULSTAR Reactor stack. During July 1996, a TLD station was added to North Hall which is a student dormitory located 402 meters northeast of Burlington Labs. Also, the TLD station on David Clark Labs was moved to the Environmental Health and Safety Center. A control station is located in Room 107 of the Environmental Safety Center. Table 6.1 gives the data for these seven (7) monitoring locations.

The observed exposures are those expected to be produced by background radiations in this area of North Carolina. The data of Table 6.1 agrees well with the state-wide average exposure rate of

~ 18 - 20 mR per quarter year.

1 17 '

Table 2.2 Aerially Transported Gamma Activityj (fCi m E-3)

J NUCLIDES SAMPUNG PERIOD Co-57 Co-60 Nb-95 Zr-95 Ru-103 Ru-106 Cs-137 Ce-141 Ce-144 1995 06/29- 07/06 0.17 0.24 0.31 0.47 0.26 2.28 0.23 1 0.41 1.36 _

07/06 - 07/13 0.24 0.40 0.39 0.60 0.33 3.10 0.39 0.46 1.96 07/13- 07/20 0.27 0.43 0.38 0.60 0.34 3.10 0.42 0.49 2.14 07/20 - 07/27 0.17 0.40 0.32 0.57 0.30 2.80 0.29 0.37 1.43 07/27- 08/03 0.17 0.38 0.33 0.55 0.30 3.10 0.32 0.36 1.47 08/03-08/10 0.31 0.47 0.48 0.67 0.46 4.50 0.50 0.53 2.24 08/10- 08/17 0.18 0.37 0.35 0.62 0.33 3.30 0.33 0.44 1.52 08/17 -08/24 0.19 0.37 0.34 0.52 0.33 3.10 0.38 0.39 1.58 08/24 - 08/31 0.21 0.36 0.34 0.53 0.31 3.10 0.34 0.37 1.58 08/31 - 09/07 0.17 0.30 0.29 0.49 0.29 2.70 0.31 0.33 1.39 09/07- 09/14 0.17 0.37 0.33 0.51 0.29 2.80 0.35 0.35 1.45 m 09/14 - 09/21 0.17 0.33 i O.27 0.50 0.28 2.70 0.29 O.33 1.33 09/21 - 09/28 0.18 0.31 0.28 0.46 0.28 2.40 0.27 0.35 1.26 09/28 -10/05 , 0.14 0.29 0.28 0.39 0.23 2.30 0.26 0.28 1.17 10/05 -10/12 I O.16 0.31 0.27 0.47 0.26 2.40 0.26 0.33 1.16 10/12-10/19 0.17 0.30 0.25 0.43 0.21 2.30 0.28 0.28 1.16 10/19-10/26 0.19 0.34 0.29 0.47 0.22 2.60 0.29 0.29 1.51 10/26-11/02 0.17 0.29 0.22 0.40 0.23 2.30 0.25 0.28 i 1.27 11/02 -11/09 j O.16 0.29 0.25 0.45 0.25 } 2.20 0.24 0.31 1.29 11/09-11/16 O.18 0.28 0.27 0.43 0.26_ 2.30 0.26 0.31 1.31 11/16 -11/28 0.18 0.31 0.26 0.42 0.27 2.40 0.27 0.33 1.38 11/28-12/06 0.17 0.31 0.29 0.38 0.27 2.60 0.29 0.30 1.46 12/06-12/13 0.15 0.30 0.34 0.60 0.41 2.30 0.24 0.34 1.32 12/13 -12/20 0.16 0.29 0.33 0.55 0.39 2.40 0.25 0.33 1.29 12/20-12/29 0.16 0.26 0.27 0.50 0.36 2.10 0.24 0.31 1.29 1996 01/15-01/22 0.17 0.28 0.33 0.48 0.29 2.28 0.27 0.34 1.37 05/22-05/29 0.16 0.3 0.31 0.52 0.25 2.35 0.29 I~ O.38 l 1.39 e

I l s f0 1

7. ' QUALITY CONTROL INTERCOMPARISON PROGRAM The Environmental Radiation Surveillance Laboratory of the Radiation Protection Office has participated in the U.S. EPA Environmental Laboratory Intercomparison Studies Program during this reporting period. The objective of this program is to provide laboratories performing i environmental radiation measurements with unknowns to test their analytical techniques. In l January 1996, the Radiation Protection Office was informed that due to uncertainties in EPA's

! budget, the distribution of some performance evaluation samples would be discontinued.

j Accordingly, this laboratory received only air filters for the 1995-96 intercomparison studies. The results of the intercomparison studies are given in Tables 7.1 a-c. All samples are analyzed in triplicate and reported as an average value with an experimental sigma (1s).

The Radiation Protection Office is currentlly attempting to obtain blind performance evaluation samples from another source.

Appendix 1 gives an explanation of the quantities listed in the tables and an example calculation.

l l

l 19

=

l 1 TABLE 7.1a GROSS ALPHA ACTIVITY AIR FILTER --INTERCOMPARISON STUDY 25 AUGUST 1995 i  !

The known value for gross alpha activity is 25.0 pCi/ filter with an expected laboratory precision of l 6.3 (1s,1 determination).

1 e

l I NCSU - ENVIRONMENTAL LABORATORY RESULTS i Exper. Rng anal Normalized deviation Res.1 Res. 2 Res. 3 Sigma (R + SR) Average (grand-avg) (known) 26.1 25.8 26.5 0.35 0.066 26.13 -0.14 0.31 l

! l i

\

STATISTICAL

SUMMARY

OF 182 PARTICIPANTS J 1 Statistic Resoondents Non-outliers  !

Mean 27.10 Grand Avg 26.65 Std. Dev. 6.47 3.98  ;

Variance 41.88 15.83 l

% Coef. of Var. 23.88 14.93  !

% deviation of mean from known value 8.40 6.62 l Norm. dev, of mean from known value 0.32 0.42 Median 26.00 25.68

% deviation of median from known value 4.00 3.53 Nor. dev. of median from known value 0.15 0.22 l

4. ,

i i

20 l

l

TABLE 7.1b GROSS BETA ACTIVITY AIR FILTER -INTERCOMPARISON STUDY 25 AUGUST 1995 The known value for gross beta activity is 86.6 pCi/ filter with an expected laboratory precision of 10.0 (1s,1 determination).

NCSU - ENVIRONMENTAL LABORATORY RESULTS GROSS BETA Exper. Rng anal Normalized deviation Res.1 Res. 2 Res.3 Sigma (R + SR) Averaae (arand-ava) (known) 81.3 83.8 79.5 2.16 0.254 81.53 -1.01 -0.88 STATISTICAL

SUMMARY

OF 182 PARTICIPANTS Statistic Resoondents Non-outliers Mean 89.82 Grand Avg 87.38 Std. Dev. 21.06 8.81 )

Variance 443.62 77.54 l

% Coef. of Var. 23.45 10.08 l

% deviation of mean from known value 3.71 0.90 Norm. dev. of mean from known value 0.15 0.09 Median 87.48 87.30

% deviation of median from known value 1.02 0.81 i Nor. dev. of median from known value 0.04 0.08 21

l' i

TABLE 7.1c "7Cs ACTIVITY AIR FILTER -INTERCOMPARISON STUDY 25 AUGUST 1995 l The known value for Cesium-137 activity is 25.0 pCi/ filter with an expected laboratory precision of 5.0 (1s,1 determination).

NCSU - ENVIRONMENTAL LABORATORY RESULTS is7g Exper. Rng anal Normalized deviation Res.1 HeL_2 Res.3 Sigma (R + SR) Average (arand-avg) (known) 30.0 30.0 30.0 0.00 0.000 30.00 1.09 1.73 1

STATISTICAL

SUMMARY

OF 182 PARTICIPANTS l Statistic Resoondents Non-outliers Mean 28.06 Grand Avg 26.85 Std. Dev. 9.86 3.88 Variance 97.27 15.08

% Coef. of Var. 35.15 14.46

% deviation of mean from known value 12.24 7.39 Norm. dev. of mean from known value 0.31 0.48 Median 26.33 26.33

% deviation of median from known value 5.33 5.33 Nor. dev. of median from known value 0.14 0.34 I

22

s

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 (e.g., Be-7) 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.

9. ACKNOWLEDGMENTS This office is greatly indebted to Mr. Bill Crocker for his untiring efforts in collecting the environmental samples. Great appreciation is also expressed to Mr. Thomas Brackin for his work in repairing the air -

samplers.

The graphs and arrangement of this report are available due to the assistance of Ms. Joy L.

Douglass.

l l

23

J l

APPENDIX 1 t The vertical columns in Tables 7 are identified as columns 1-8 from left to right.  :

)

Column 1,2,3: Laboratory results given in triplicate.  !

Column 4: Standard deviation (1s) of the experimental results.

Column 5: Normalized range value in "mean range + standard error of the range".

Column 6: Average value of the triplicate analysis.

Column 7: Normalized deviation from the grand average value of alllaboratories expressed in o, units.

Column 8: Normalized deviation from the known value expressed in o, units.

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, on. 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, om. 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 waming levels. The accuracy of the data is acceptable.

Finally, the experimental error of all laboratories, the grand average, and the normalized deviation from the grand average are calculated in order to ascertain the performance of all the laboratories as  ;

a group. Any bias in methodology or instrumentation may be indicated by these results. );

i 24

1 o

I ,

l 6 EXAMPLE CALCULATIONS Experimental Data:

Known value = p = 3273 pCi 8H/ liter on September 24,1974 i Expected laboratory precision = a = 357 pCi/ liter 1

Samole Result l

l X, 3060 pCi/ liter X2 3060 pCi/ liter X3 3240 pCi/ liter Mean = Y X 9360 Y = =

3 = 3120 pCi/ liter where N = number of results = 3 Experimental sigma = s

( X,)2 11 s = ( X, ) 2_

21 N h N-1 (3060)2+(3060)2+(3240)2, (3060+3060+3240)2 3

h 2 s = 103.9 pCi/ liter Range = r r = 1 maximum result - minimum resulti r = 13240 - 30601 r = 180 pCi/ liter 25 l

e 6

e Range Analysis (RNG ANLY)*

Mean range = R R = d0 2 where d2 ** = 1.693 for N = 3

=

(1.693)(357)

R = 604.4 pCi/ liter Controllimit = CL CL = R + So n

=

D.R where D.** = 2.575 for N = 3 i

=

(2.575)(604.4)

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

on i

4 on = (R + 30a - R) + 3

=

(D.R - R) + 3

= (1556-604.4) + 3 ,

on = 317.2 pCi/ liter l Let Range = r = wR + xca = 180 pCi/ liter i Define normalized range = w + x for r > R, w = 1 then r = wR + xon = R + xan r-R l or x= I on r-R therefore w+x=1+x=1+

on

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

AOCS Reoort 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. 20.d Edition. The Chemical Rubber Co., Cleveland, Ohio,1968, p. 454.

26 l

l

O 6

o for r s R, x = 0 then r = wR + xon = wR r

or w=

R r

therefore w + x = w + 0 =

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

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

= 3120 - 3273 D = -153 pCi/ liter Standard error of the mean = 0, o

o, =

v'N l

357

=

v'3 l l

c, = 206.1 pCi/ liter D

ND =

0,

-153

=

206.1 ND = -0.7 Controllimit = CL CL = (p i 30 )

27

o 4

Waming limit = WL WL = (p i 20.)

Experimentalsigma(alllaboratories) = si

( x,)2 fx 11 2_ s1 N

h N-1 162639133 -

(49345)2 15 h 14 si = 149 pCi/ liter Grand Average = GA a i x

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' -

Um

-170

=

206.1 N D' = - 0.8 l

28

., . - . . - - _ _ _ .