ML20099K272

From kanterella
Jump to navigation Jump to search
Environ Radiation Surveillance Rept for Jul 1991-June 1992
ML20099K272
Person / Time
Site: North Carolina State University
Issue date: 06/30/1992
From: Harris R
North Carolina State University, RALEIGH, NC
To:
Shared Package
ML20099K266 List:
References
NUDOCS 9208260006
Download: ML20099K272 (34)
v • d • e


Text

. . . . _ _ _ _ . _ . . __._.. _._ _ _ . _ _. _ _ _ . _ . - . . . . _ _ . -

RADIATION PROTECTION OFFICE- '

NORTH CAROLINA STATE UNIVERSITY ENVIRONMENTAL RADIATION SURVEILLANCE REPORT FOR THE PERIOD JULY 1,- 1991 - JUNE 30,1992 l.

1 o

l-R ALTON J. H ARRIS ENVIRONMENTAL HEALTH PHYSICIST Y208260006 920821

'{DR ADOCK 05000297 PDR-3

TABLE OF CONTENTS PAGE NO.

1. INTRODUCTION 1
2. AIR MONITORING 2 Table 2.1 Location of Air Monitoring Stations 2 Figures 2a-2a Airborne Gross Beta Activities 37 Table 2.2 Aerially Transported Gamma Activity 89 Table 2.3 Regulatory Limits, Alert Levels and Background Levels for Airborne Radioactivity --

10

3. MILK Table 3.1 11 i
4. SURFACE WATER

~

Tabte 4.1 Gross Alpha and Beta Activity in Surface Water 12 Table 4.2 LLD Values for Gamrna 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 - 7.1h 19 26

8. CONCLUSIONS 27
9. ACKNOWLEDGMENTS 27 APPENDIX 1 -

28 i

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 legalliability obligations; and
5) Providing public assurance and acceptance.

During June 1992, the environmental program was reviewed by Mr. Craig Bassett of the U.S.

Nuclear Regulatory Commission. The conclusion of his inspection was that the environmental monitoring program was being conducted adequately. (NRC Inspection Report No. 50-297/92 01).

1

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

This reporting period ends one (1) full year of operating the new air samp!ing systems installed at the live campus locations listed in Table 2.1. With the exception of a few minor wiring problems, these samplers have operated nearly continuously (24 hrs per day) without any malfunctions. Instances of missing data for the stations at Clark Labs, Withers Hall, and Riddick Hall are due to undersized wiring in the sampler unit which caused the fuse to blow. This problem has now been corrected.

Figures 2a thru 2e show bar graphs of gross beta activity (fCi/ cubic meter vs. week number). The highest gross beta activny observed was 28.2 fCi m 3 and the yearly campus averaqo was 11.7 fCi m-3. The bar at week number 44 represents a two week period from 04/29/92 to 05/15/92. The air samplers were allowed to run continuously during the period without changing the filters to examine the effect of excessive dust loading. The results indicate that this probably causes decreased retention efficiency for airbome particulates and leads to an underestimation of the true gross beta activity of the filters.

Table 2,2. lists LLQ values for several gamma emitters which would be indicative of fission product activity Ng_ gamma activitvjue to any of these radionuclides was detected. An examination of Table 1 2.2 reveals that around 09/12/91 LLD values for some of the listed radionuclides increased by a factor of 2 to 3. The explanation for this increase was slow in forthcoming due to another sporadic electronics problem in the MCA computer system. Failure of the detector preamplifier was finally diagnosed as the problem by the manufacturer. This problem has now been corrected. The reliability of the data acquired during this period was assured by counting a calibrated mixed gamma standard.

TABLE 2.1 LOCATION OF AIR MONITORING STATIONS SjIE DIRECTIONI DjSTANCE2 ELEVATION 3 I

(meters) (meters)

BROUGHTCN SOUTHWEST 125 -17 DAVID CLARK LABS WEST 500 -18 LIBRARY NORTHWEST 192 +11 RIDDICK SOUTHEAST 99 -14 WITHERS NORTHEAST 82 6 1 DIRECTION-DIRECTION FROM REACTOR STACK 2 DISTANCE-DISTANCE FROM REACTOR STACK 3 ELEVATION-ELEVATION RELATIVE TO THE TOP OF THE REACTOR STACK 2

FIGCRE 2a

~

A E L"T'E SI ' i S , O ,L (1 /CU  !

LLDal fCi/ CUBIC M i

CLARK LABORATORIES 3

i t

g C 25 c 20

. u i r . . . . . . . .. . . .

====== Week Number

! WEEK NUMBER FROM JULY 02, 1991 TilROUG11 JULY 01, 1992 JULY O2 BEGINS AT WEEK #1

l

~

FIGURE 2b

~

AIRBORNE GROSS BETA ACTIVITY REGULA111RY LUf1T=1000 fCi/ Cubic M -

N. C. STATE UNIVERSITY CAMPUS 4M RT L '

5 fC'/ CUBIC M BROUGHTON HALL 25

, 7 b 2o C

L!]l1ll1111lli111 =======

. WEEK NJMBER FROM JULY 02, 1991 THROUGli JUL' 11 992 JULY O2 Bl. GINS AT WFEK #1

l l

l

==== ====-

LLD~1 f Ci/ CUBIC ?!

RIDDICK HALL Illl1111lIlIIIlliiJllllil1

= = = = = = Week Number l

1:EEK NDISER FRO!! JULv O2, 1991 THROCCH JULT 01, 1992 aUty 02 uEc1ss ar uEEx *1

FIGURE 2d AF L 'I\ SI A3I ITS , 1FL 0 /CU ft LLD-1 fCi/ CUBIC M  !

WITHERS HALL m

l f 2oI l

lIlILlllIIl1IIIIiiIlll ====== Week Number WEEK NUMBER FROM JULY 02, 1991 TilROUGil JULY 01, 1992 f JULY 02 BEGINS AT WEEK !!i i

FIGURE 2e

~

S AT 'Il .I I S e\ RT T \ ., O C:r Si LLD-1 fci/Ct'BIC M D H HILL LIBRARY 25 -

h 2o :

/ c 15 012s 567 90 234567890 2 67890 2 't 567890 Week Number i WEEK NUMBER FROM JITLY 02, 1991 TIIROUG11 JtTLY 01, 1992 JULY 02 BEGINS AT WEEK #1

TABLE 2.2 AERIALLY TRANSPORTED GAMMA ACTIVITY (LLD Values in fCi m ~3)

NUCLIDES Ru-103 Ro-106 C s- 137 C 2- 141 Ce-144 SAMPU"JG PERIOD Co-57 Co-60 Nb-95 Zr-95 1991 0.28 0.96 0.11 0.26 0.63 07/02-07/09 0.08 0.13 0.17 0.17 0.59 0.25 1.0 0.11 0.23 07/09-07/16 0.08 0.12 0.15 0.14 0.61 0.26 0.14 0.99 0.12 0.21 0.08 0.12 0.14 07/16-07/23 0.24 0.14 1.0 0.11 0.18 0.61 0.08 0.12 0.13 07/23-07/31 0.31 0.18 1.5 0.16 0.23 0.84 07/31-08/06 0.11 0.19 0.19 0.49 0.18 0.10 0.79 0.09 0.12 08/06-08/13 0.06 0.11 0.09 0.65 0.13 0.12 1.0 0.12 0.15 08/13-08/20 0.08 0.13 0.13 0.47 '

^ 15 0.09 0.77 0.09 0.11 0.06 0.10 0.10 .

08/20-08/28 0.27 1.4 0.16 C.20 0.91 0.12 0.19 0.18 0.17 O8/28-09/03 0.15 0.67 " 08 0.10 0.42 0.06 0.09 0.08 0.08 w 09/03-09/12 1.7 0.19 0.25 1.1 0.14 0.23 0.21 0.32 0.20 09/12-09/17 1.5 0.19 0.22 1.0 0.13 21 0.21 0.30 0.18 09/17-O9/24 0.44 0.22 1.9 0.22 0.33 1.1 09/24-10/01 0.14 0.27 0.24 1.0 0.38 0.20 1.5 0.18 0.28 0.13 0.23 0.21 10/01-10/08 0.40 2.1 0.22 0.32 1.2 0.16 0.29 0.24 0.21 10/08-10/15 0.37 0.19 2.1 014 0.29 1.1 10/15-10/22 0.15 0.31 0.23 0.52 0.28 2.9 0.32 0.37 1.7 0.22 0.36 0.35 10/22-10/29 0.48 2.3 0.26 0.37 1.3 0.16 0.28 0.29 0.26 10/29-11/06 0.28 0.37 1.4 0.18 0.35 0.2s 0.48 0.26 2.6 11/06-11/13 0.44 0.23 '3 4 0.26 0 ,3 1.2 0.16 0.30 0.25 11/13-11/19 3.6 0.45 0.51 2.1 0.27 0.50 0.40 0.77 0.38 11/19 11/27 0.73 3.7 0.39 0.52 2.0 0.24 0.50 0.40 0.39 11/27-12/03 0.47 2.3 0.27 0.33 1.3 0.17 0.32 0.25 0.25 12 /03 - 12 /10 0.31 0.44 1.6 0.21 0.43 0.33 0.55 0.29 2.9 12 /10 12 /16 0.43 2.1 0.23 0.30 11 0.15 0.28 0.24 0.21 I 12/16-12/20 0.44 0.22 2.0 0.24 0.29 1.2 12/20-12/31 0.16 0.32 0.J6 ALL ENTRIES IN TABLE 2.2 ARE LLD VALUES.

1 5

TABLE 2.2 AERIALLY TRANSPORTED GAMMA ACTIVITY (LLD Value5 in fCi m-3) . I NUCLIDES i

SAMPUNG PERIOD Co. 57 Co-60 Nb-95 Zr-95 ' Ru- 10 3 Ro-106 Cs- 13 / C e-141 Ce-144 1992 ,

0.14 0.22 0.42 0.19 1.9 0.22 0.26 11 12/31-01/07 0.26 0.32 0.28 0.47 0.25 2.3 0.27 0.26 1.3 01/07 01/14 0._1 7 --

01/14-01/21 --- --- --

POWER FAILURE --- -- -

01/21-01/28 0.19- 0.37 0.33 0.53 0.30 2.7 0.4 0.41 .1.5 ,

0.20 0.36- 0.36 0.65 0.34 2.8 032 0.49 1.5 01/28-02/04 02 04-02/11 0.22 C.41 /'2-0.80 0.44 2.9 032 0.65 13 0.21 0.39 0.32 0.46 0.30 2.3 0.25 038 1.3 02/11-02/18 0.16 0.29 0.26 2.2 0.24 0.37 1.2 i 02/18-02/26 0.26 0.49 0.17 0.26 0.28- 0.45 0.27 23 0.23 0.34 1.3 02/26-03/04 0.32 0.61 0.61 0.57 4.6 0.50 0.81 2.5

, 03/04-03/10 1.1 0.22 0.25 0.24 0.40 0.3 2.4 0.27 0.31 14 O3/10-03/17 0.20 0.26 0.25 C.21 23 0.26 0.26 1.3 03/17-03/24 0.39 ,

0.25 0.26 0.23 2.5 030 0.28 1.2 03/24-04/02 0.21 0.34 0.24 0.30 0.22 2.4 0.28 032 1.5 04!02-04/07 0.31 0.29 0.30 0.22 0.29 0.28 0.27 2.2 031 0.35 14 04/07-04/i4 0.24 031. 0.28 0.32 0.31 2.3 0.27 0.29 1.3 04/14-04/21 0.22 0.27 0.29 0.26 0.27 1.2 04/21-04/29 0.26 0.29 2.1 0.42 0.39 2.7 0.25 0.58 1.5

  • O4/29-05/15 0.23 0.43 0.76 0.21 0.28 0.31 0.32 0.2? 2.1 0.31 0.40 l4 05/15-05/22 ,

0.27 0.19 2.0 0.26 0.31 1.3 05/22-05/27 C'.24 0.27 0.29 0.07 0.11 0.11 0.18 0.11 0.9 0.10 0.14 0.53 05/27-06/03 0.07 0.12 0.10 0.16 0.10 0.9 0.09 0.14 0.50 06/03-06/10

  • 0.62 06/10-06/16 0.08 0.14 0.11 0.18 0.11 0.9 0.12 0.14 0.09 0.17' O.14 0.21 0.11 1.0 0.12 0.15 0.65 06/16-06/23 0.08 0.14 0.11 0,20 0.11 0.9 0.11 0.14 0.63 06/23-07/01
  • SAMPLE TAKEN OVER A TWO WEEK PERIOD

4 TABLE 2.3 REGULATORY LIMITS, ALERT LEVELS, AND BACKGROUND LEVELS FOR AIRBORNE RADIOACTIVITY (fCi m 3)

REGULATORY ALERT AVERAGE N.C.

ECA'QE LlM1I LEVIL BA6KGPOUN_Q LEVEL GROSSALPHA 20 10 4 GROSSBETA 1000 500 100 Cs 137 5 x 105 10 2 Ce-144 2 x 105 100 o Ru-106 2 x 105 30 0 1-131 1 x 105 10 0

Reference:

Environmental Radiation Surveillance Report 1986 88, State of N.C.

Radiation Protection Section 10

_ ._. . . . _ _ _ .._- _ __ _ _ _ _ - . _ _ ~ __

P

3. MlM (TABLE 3.1)

Milk samples are collected each morith from the Campus Creamery, the Lake Wheeler Road Dairy and the Randleigh Dairy Farm.

The FDA's Preventive Action Guide (PAG) for 14131 is 1.5 X 10 4 pCi/ liter for infants. All analyses during this period show activities at least three (3) orders of magnitude below the PAG.

The analyses are performed in duplicate and the higher value is reported in each case.

TABLE 3.1 1131 IN COWS' MILK (pCl liter-1 11 c) LLD - 3 pCiliter 1 pCi liter -1 DATE CAMPUS CREAMERY LAKE WHEELER RANDLEIGH JULY 1991 s 3.3 s 3.4 s 3.3 AUGUST 1991 No SampleData No Sample Data No Sample Data SEPTEMBER 1991 s 1.4 s 1.4 s 1.4 OCTOBER 1991 s 3.0 s 3.0 < 3.0 NOVEMBER 1991 s 3.0 s 3.0 s 3.0 DECEMBER 1991 s 3.0 s 3.0 s 3.0 JANUARY 1992 s 3.5 s 3.5 s 3.5 FEBRUARY 1992 s 3.0 s 3.0 s 3.0 MARCH I992 s 3.0 s 3.0 s 3.0 APRIL 1992 s 4.0 s 4.0 s 4.0 MAY 1992 s 3.0 s 3.0 s 3.0 JUNE 1992 s 3.0 s 3.0 s 3.0

  • Samples lost due to refrigerator malfunction.

I 11 l

l-

4. SURFACE WATEB (TABLES 4.1 Af JD 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 pCiliterl and - 0.6 pCiliter1, respectively. For gross alpha activity the Alert Levelis 1 5 pClliterl and the Regulatory Limit is 15 pCiliteri. For gross beta activity the Alert Levelis 12.5 pCl liter 1 and the Regulatory Limit is 50 pCiliter1. Samples with gross alpha or beta activities exceeding these Alert Levels would require gamma analysis to identify the radionuclides l present. A problem with the HPGe gamma detection equipment required a recalibration of detection I officiencies. The LLD values in Tabic 4.2 are for the second quarter of 1992.

TABLE 4.1 GROSS ALPHA AND BETA ACTIVITY IN SURFACE WATER (pCiliter 1 2 c)

  • LLD a ~ 0.4 pCiliter1 LLDp - 0.4 pCi liter 1 oCi liter 1 GTES GESS DATE LOCATION ALF1LA BEEA THIRD OUARTER 1991 ON < 0.3 < 0.4 OFF < 0.3 < 0.4 FOURTH OUARTER 1991 ON < 0.4 1.6 0.4 OFF < 0.4 1.1 0.4 FIRST OUARTER 1992 ON < 0.3 < 0.4 OFF < 0.3 < 0.4 SECOND OUAR',ER 1992 ON < 0.5 1.7 i 0.4 OFF < 0.5 < 0.4
  • f I D VALUES ARE DETERMINED QUARTERLY 12

TABLE 4.2 LOWER LIMITS OF DETECTION FOR SEVERAL GAMMA EMITTERS IN SURFACE WATER FROM NCSU ERSL ANALYSIS

'l NUCLIDE LLD (DCi liter 1)

Co 60 0.4 Zn 65 0.7 Cs-137 0.3 Cs 134 0.4 St 85 0.4

' Ru-103 0.3 Ru-106 3.0 Nb-95 0.4 Zr 95 0.5

  • LLD VALUES ARE FOR THE 2rJD OUARTER OF 1992 13

- . . - _ . ~ . . - - . .. -_. - - . - - - --- - . . - . . - - - - . .

5. YE(AETATION (TABLE 5.1 and G.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 gram 1. Table 5.2 lists LLD values for several gamma emitters. No gamma activity due to any of these radionuclides has been observed in campus

.ugetation. The beta and gamma activities are reported as pCi per gram of green vegetation.

TABLE 5.1 GROSS BETA ACTIVITY IN CAMPUS VEGETATION LLD - 0.5 pCl g 1

- SAMPLE DATE SAMPLE LOCATION (pCi a-1 loj DECEMBER 1991 NORTH CAMPUS 2.6 1 0.1 DECEMBER 1991 SOUTH CN-APUS 2.4- 0.1 DECEMBER 1991 EAST CAMPUS 3.3 1 0.1 DECEMBER 1991 WEST CAMPUS 2.3 1 0.1 JUNE 1992 NORTH CAMPUS 2.7 1 0.1 JUNE 1992 SOUTH CAMPUS 4.6 1 0.2 JUNE 1992 EASTCAMPUS 2.9 0.1 JUNE 1992 WCST CAMPUS 2.9 1 0.1 "LLD values are dete. mined semiannually I

d I

d 14

l Table 5.2 - LLD VALUES FOR GAMMA EMITTERS IN VEGETATION NUCLIDE LLD (oCi oram-1)*

Co-60 0.01 Zn-65 0.02 Cs-137 0.01 Cs 134 0.01 4 Sr85 0.01 Ru 103 0.01 Nb95 0.01 Zr 95 0.02

  • LLD VALUES ARE FOR THE 2ND QUARTER OF 1992 15

I l

. l 4 4

6. THERMOLUMjNESCENT DOSIMETERS (TLDs) (TABLE 6.1)

TLD analysis is contracted to Teledyne isotopes for determination of ambient gamma exposures. Tbe dosimeters are CaSO4doped with dysprosium and have a manufacturer stated sensitivity of 0.5 3.0.15 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. A control station is located in 214 David Clark Laboratories. Table 6.1 gives the data for these seven (7) i sampling locations for the period 04/29/91 to 04/07/92.

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.

f l

l 16

k TABLE 6.1 ENVIRONMENTAL TLD EXPOSURES (mR/OUARTER YEAR i2 o )

DATE WITHERS RIDDICK BRCUGHTCN UBRARY DAVID CLARK PULSTAR STACK CCNTROL ,

04/29/91-06/27/91 10.4 1.4 17.4 1.9 14.2 0.8 18.0 1.9 10.3 2.7 6.820.9 13.2 4.0

'12.2i0.7 19.6 2.4 14.7 1.0 17.2 2.3 12.2 0.6 12.0 1.1 12.9 3.2 06/27/91-09/27/91 09/27/91-01/02/92 14.8 1.4 22.0 1.9 18.2 1.5 19.3 1.2 12.4 2.8 13.2 1.2 15.9 1.3 01/02/92-04/07/92 13.5 1.6 21.4 3.4 19.0 2.1 19.3 1.8 12.4 1.2 12.7 0.7 14.5 1.3

---.- ---- DATA NOT YET AVAILABLE - . . - - .

04/07/92-06/27/92 C

  • THIS DATA WAS UNAVAILABLE FOR INCLUSION IN THE 1990-91 REPORT.
7. QUALITY CONTBDL INTERCOMPARISON PROGRAM T he Environmental Radiation Surveillance Laboratory of the Radiation Protection Office has l participated in the U. S. EPA Environmental Laboratory Intercomparison Studies Program during this l reporting period. The objective of this program is to provide laboratories performing environmental I radiation measurements with unknowns to test their analytical techniques. The results of the intercomparison studies are given in Table 7.1 a h. All samples are analyzed in triplicate and reported as an average value with an experimental sigma (1s).

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

=

k

+

TABLE 7.1a GROSS ALPHA ACTIVITY AIR FILTER-INTERCOMPARISON STUDY

- 30 AUGUST 1991 The known value for gross alpha activity is 25.0 pCi/ filter with an expected laboratory precision 6.0 (1s,1 determination).

NCSU - ENVIRONMENTAL LABORATORY RESULTS ALPHA ,

Exper. Rng anal Normalized deviation Lab Res.1 He.sl Res. 3 Sioma (R 4 SR) Ayerage (crand-avo) (known)

CA 25.0 25.0 27.0 1.15 0.197 25.67 -0.77 0.19 STATISTICAL SUMMAR')F 172 PARTICIPANTS Statistic Resoondents Non-outliers Mean 29.12 Grand Avg 28.33 Std. Dev. 11.82 5.03 Variance 139.72 25.35

% Coef. of Var. -40.58 17.77

% deviation of mean from known value 16.50 13.31 Norm. dov. of mean from known value 0.35 0.66 Median 27.33 27.33 -

% deviation of median from known value 9.33 9.33 Norm, dev. of median from known value 0.20 0.46 19

-TABLE 7.1b GROSS BETA ACTIVITY AIR FILTER INTERCOMPARISON STUDY . l 30 AUGUST 1991 The known value for gross beta activity is 92.0 pCi/ filter with an expected laboratory precision of 10.0 (1s,1 determination).

NCSU - ENVIRONMENTAL LABORATORY RESULTS BEIA Exper. Rnqunal Normalized deviation Lat2 Res.1 Res.2 Res.3 Sigma (R + SR) Average (crand avaWknqwty Q\ 95.0 97.0 96.0 1.00 0.118 96.00 0.08 0.69 STATISTICAL

SUMMARY

OF 172 PARTICIPANTS Slal1111C Resoondents lion-outliers Maan 97.25 Grand Avg 95.54 Std. Dev. 20.93 9.04

. Variance 438.26 81.80

% CoeI, of Var. 21.53 9.47

% deviation of mean from known value 5.71 3.85 Norm. dev. of mean from known value 0.25 0.39 Median 95.00 95.00

% deviation of median from known value 3.26 3.26 Norm, dev. of median from known value 014 0.33 20

TABLE 7.1c 137Cs ACTIVITY AIR FILTER INTERCOMPARISON STUDY-30 AUGUST 1991 The known vatuo for Cesium 137 activity is 30.0 pCi/fdter with an expected laboratory precision of 5.0 (1s,1 dolormination).

i UCSU . ENVIRONMENTAL 'JBORA' ?RY RESLILTS 131 C1 .

Expor. Normalized deviation i Rn0 anal I

Lith Res.1 Res.2 Res. 3 Siama (R + SR) Averace (orand avoMknown)

CA 31.00 31.L 1 31.00 0.00 0.000 31.00 -0.51 0.35 1 STATISTIC AL SUMM ARY OF 172 PARTICJEANTS f Statistig Respondents Non:outfiers Moan 36.36 Grand Avg 32.48 Std. Dev. 44.41 5.38 Varianco 1971.96 28.91

% Coef.of Var. 122.13 16.55 1

% deviation of mean from known value 21.20 8.26 Norm.dov.of mean from known vatuo 0.14 0.46 <

Median 31.67 .31.67

% deviation of median irre known value 5.56 C 56 Norm. dev, of median from known value 0.04 L.31 i

r

(

r 21 l ,

f ,

l l

I TABLE 7.1d GROSS ALPHA ACTIVITY AIR FILTER . INTERCOMPARISON STUDY -

27 MARCH 1992 l

l l

The known value for gross alpha activity is 7.0 pCi/ filter with an expected laboratory precision el 5.0 (1s,1 determination).

I NCSU - ENVIRC; -. AENTAL LABORATORY RESULTS l I

ALPHA Exper. Rng anal Normalized deviation Latz Res.1 Res. 2 Res. 3 Sigma (R + SR) Avernae forand-ava)(known)

CA 8.0 7.0 9.0 0.58 0.118 7.67 0.24 0.23 l

l l

STATISTICAL

SUMMARY

OF 179 PARTICIPANTS l

l Statistical _Resoondents Non.. outliers Mean 9.25 Grand Avg 8.35 Std. Dev. 7.20 1.69 Variance 51.88 2.84

% Coef.of Var. 77.88 20.20

% dovlation of mean from known value 32.13 19.25 Norm. &v, of mean from known value 0.31 0.80 Median 8.00 8.00-

% deviation of median from known value 14.29 14.29 .

Nortn. dev. of median from known value 0.14 0.59 i

i 4

-, , . . ~ . . - . - . . ~ . . .- -. .-.-- - .. - .- ..--.-.- - . -.,,--- - . . , . . . . . . . - . . - - - - - - - . . -

4 TABLE 7.10 GROSS BETA ACTIVITY AIR FILTER INTERCOMPARISON STUDY 27 MARCH 1992 The known value for gross beta activity is 41.0 pC# filter with an expected laboratory precision of 5.0 (1s,1 determination).

I NCSU - ENVIRONMEtITAL L/60RATORY RESULTS Dria Exper. Rnp anal Normalized deviation Lab Res.1 Bes 2 Res.3 Sigma (R 4 SR) Averaan forand-avauknown)

CA 42.0 4 ?.0 42.0 0.00 0.000 42.0 -0.11 0.35 STATISTIC AL SLIMMARY OF 179 PARTICIPANTS Statistic Bescondents Non-outliers Mean 42.19 Grand Avg 42.32 Std. Dev. 10.06 3.31 Variance - 101.17 10.98

% Coef. of Var, 23.84 7.83

% deviation of mean from known value 2.90 3.23 Norm.dev of mean from known valun 0.12 0.40 Median 42.00 42.00

% deviation of median from known value 2.44 2.44 Norm. dev. of rnedian from known value 0.10 0.30 i

l l

l 23

I T ABLE 7.1f GROSS ALPHA ACTIVITYIN WATER lNTERCOMPARISON STUDY 15 MAY 1992 1ho known value for gross alpha activity is 15.0 pCillitor with an expected laboratory precision of 5.0 (1s,1 deto mination).

NCSU - ENVIRONMENTAL [1GORATORY RESULTS GROSS ALPHA Exper. Rng anal Normalized deviation Lab Res.1 Res.2 Bes.3 E!Qma (R .+ SBl Averago forand-ava)(known)

CA 17.0 18.0 16.0 1.00 0.236 17.00 0.92 0.69 STATISECAL

SUMMARY

OF 233 PARTICIPANTS Statistic _ Resoondents Non-outliers Mean - 16.13 Grand Avg 14.34 Std. Dov. 12.25 4.94 Varianco 150.15 24.30

% Coof, of Var. 75.97 34.41

% deviation of mean from known valuo 7.53 -4.37 Norm, dev. of mean from known valuo 0.09 0.13 Median 14.33 14.17

% deviation of median from known value -4.44 - -5.56 Norm. dov. of rnodian from known value -0.05 0.17 l

4 u

_ _ ..~ _ - _ ..

, TADLE 7.1g GROSS DETA ACTIVITY IN WATER INTERCOMPARISON STUDY

. 15 MAY 1992 j 1

l The known valuo for gross beta activity is 44.0 pC'vliter with an expected laboratory procision of ,

5.0 (1s,1 dolormination). I UGSU . ENVIRONMENTAL LABORATORY RESULIS l l

QRQSS BETA l Expor. Ang anal Normalized deviation

' Lab Schl EcL.2 Ros.3 Sigma B_1.SB) Average (grand-avgMknown)

ON 39.0 39.0 38,0 0.58 0.118 38.67 -1.43 1.85 l STATISTICAL

SUMMARY

OF 233 PARTICIP/ NTS Statistic.- Respondents Non-out!!ers Mean 44.89 Grand Avg 42.79 Std. Dev. 26.78 6.81 Variance 717.24 46.42

% Coef.of Var. 59.66 15.92

% deviation of mean itom known value 2.03 2.75 Norm. dov, of mean from known valuo 0.03 0.18 Median 43.67 43.67

% deviation of median from known value -0.76 0.76

- Norm, dov, of median from known valuo -0.01 0.05 k

F l

25

- , . - _ ~ - __ -_ . . _ _ , _ _ . _ . . _ _ . . . . . _ . . . _ . - . _ _ . _ . . _ , , . - . . _ . . _ , _ . . _ - . .

TABLE 7.1h TRITIUM IN WATER li4TERCOMPARISON STUDY 21 JUNE 1991*

The known value for tritium activity is 12480.0 pCl/ liter with an expected laboratory precision of 1248.0 (1s, i dolormination).

MQSU ENVIRONMENTAL LADORATORY RESLILTS 3Lt Exper. Ang anal Normalized deviation Lab flet 1 BcL2 Res.3 Si2Wa (R + SR) Average (grand-avo)(known)

QN 14162 13995 14053 84.72 0.079 14070 2.27 2.21 STATISTICAL

SUMMARY

OF 159 PARTICIPANTS f

' Statistic Retoondents Non-outfiers Mean 12218.27 Grand Avg 12434.92  ;

Std. Dev. 1864.38 940.81 1 Variance 3475926.91 885115.64

-% Coof of Var. 15.26 7.57

% deviation of mean from known valuo 2.10 0.36 Norm dev.of meanitom known valuo 0.14 -0.05 Median 12387.67 12413.83

% deviation of median from known valuo -0.74 -0.53 Norm, dov. of median from known valuo 0.05 -0.07

  • These results have boon included in this report as they were roccived af ter submission of the 1990-91 report, i

26

_._,-.-__._._-.......,.-__._-_.~.-a

' ~

l l

8. COELUS1QUS The data obtained during this period do not show any fission product activities, lhe observed environmental radioactivity is due primarily to radon progony, primordial radionuclidos (e.g.,

K 40) and thoso radionufides (e.g., Bo-7) which originato in the upper atmosphere as the result of cosmic ray interactions. These facts justify the conclusion that the PULSTAR Reactor facility continues to operato safely and does not releaso fission product materials into the environment.

9. ACKfiQWLEDGMENTS This offico is greatly indebted to Mr. Bill Crocker for his untiring efforts in collecting tho l onvironmental samples. Great appreciation is also expressed to Mr. Thomas Brackin for his work in i rowiring the air samplers. l The graphs in this report are availablo duo to the assistance of Mr. Worth Bowman. and the entiro 7

arrangement and typing are due to the excellent oflotts of Mrs. Ginger Davis.

i I

27 4

- ~ _ . . . _ . _ , . - ,._......,_..-..m.,_ .. _ , . . . .. ., _ _ _ , . ._..., ,. _ m ,.. , . _ . . . _ _ _ . _ _ . _ . . . . . - . , - , , . . .,,,, , ,,, .,m,.., , ,. r

-m.._ ._

, , l d

APPENDie! l The vertical columns in Tables 7 are identified as columns 18 from left to right.

Column 1: Laboratory identification code (e.g., OA).

\

Columns 2,3,4: Laboratory results given in triplicato.

Column 5: Standard deviation (1s) of the o>porimental results.

Column 6: Normalized rango value in

  • moan rango + standard error of the rango".

I Column 7: Average value of the triplicato analysis.

Column 8: Normalized deviation from the grand average value of alllaboratories expressed in omunits.

Column 9: Normalized deviation from the known value expressed in m o units.

The following examplo calculation gives a set of data, the mean value, the experimental sigma, and tho

  • l rango. These statistics provido measures of the contral tendency and dispersion of the data.  !

The normalized rango is computed by first finding mean range, R, the control limit, CL, s.1d the standard error of the range, oR. The normalized rango measures the disporsion of the data (procision) in such a form that control charts may be used. Control charts allow one to readily comparo past analytical performance with prosent performanco. In the examplo, the normalized rango equals 0.3 which is loss than 3 which is the upper controllevel. The precision of the results is acceptable. '

f The normalized deviation is calculated by computing the deviation and the standard error of tho mean, am . The normalized deviation allows one to measure contral tendency (accuracy) readily through tho i use of control charts. Trends in analytical accuracy can be determined in this manner. For this examplo, the normalized deviation is 0.7 which falls betwoon +2 and 2 which are the upper and lower warning levels._ The accuracy of the data is acceptable.

Finally, the experimental error of alllaboratories. the grand averago, and the normalized deviation i

from the grand awrage are calcubted in order to ascertain the performance of all the laboratories as a L

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

28

_ ~ . _ . _ _ _ - . - . - . _ . . - . - - -

c- .- .

ExA4r>LE CALCULATIONS D perin. ental data:

r.no.n value a p 3??3 pCi 3H /11ter urine en Septenter ?4, 1974 e = 307 pCi/1fte.-

Dinted lattoratcry preci siun e latioratory Samt 10 Re <.vi t D x3 3060 pCf/ liter D xy 3060 pCi/ liter D 23 3240 pCi/ liter Mi- oe I 11 1 xi i.1 9360

= = = 3120 pCi/ liter I

N 3 where b nunber of results = 3 Cxperin, ental sigma a s

/N ,,

I r Aj N , (i-1 I (xj),

i-1 N

$ a y T N .

2 2 2 (3060 + 3060 + 3240)2 (3060) + (3060) + (3240) - 3 g ,

?

s = 103.9 pCf/ liter Rang. - r r =

l maximum result - minimum result l-r =

l 3240 - 3060l

= 180 i Ci/1 iter 29

.. < < o Range Analysis (RNC ANLY)*

Mean range a R R = da 2 where d 2 '

= 1.693 for N = 3

= (1.693) (357)

R = 604.4 pCi/11ter Control limf' = CL j CL = R + .N g

= 2.5?', for N = 3 i

= 0R4 where 04 "

= (2.575) (604.4) ,

CL = 1556 pCi/ liter Standard-error-of the range = ag "R ' (R + 3ag - R) e 3

= (04 E - R) e 3

= (1556 - 604.4) t 3 og = 317.2 pCiliiter Let range a r = wl + xoR = 180 pCi/ liter Define normalized range = w+x for r > E, w = 1-then r = wR + xag = R + xag r-R '

or x =

.og r-R therefore w+x = 1+x = 1.+

FR

  • Rosenstein, M.,-and A. S. Goldin, " Statistical Techniques for Quality Control ,

-of Environmental Radioassay," AOCS Report Stat-1_, U.S. Department of Healtn Education and Welfare, PHS, Novencer 1964.

    • From table " factors for Computing Control Limits," Handbook of Tables- for Probability and Statistics, 2nd Edition, Tne ChemicaTT<ubber Co. , Clevelind, Ohio, 1960, p. 4T4. ,

9 b

30 ,

-i

. , .._.s ._.4...,,...,..- . . _ . - . , - . . . . . _ . . _ - . . , , _ . . . . . , , ,

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

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

I i

for r<R, x = 0 then r = wX + xon = wk r

or W = -

R r

therefore w+x = w+0 -

X since r < I, (180 < 604.4.'

180 W + X =

604.4 w+x = 0.30

= ND Normalized deviation of the mean from the known value

= 0 Deviation of mean from the known value 0 = I-p

= 3120 - 3273 0- = - 153 pCi/ liter Standard error of the mean = o rn om r7 357 3

/$

Om = 206.1 pCi/ liter D

HD = -

l Om 153 706.1 '

ND = - 0.7 Control limit = CL CL = (p : 30m)

Warning Limit a WL llL = (p 2 2am) l 31

Experiacotal sign.a (all 1.boratories)

  • st fu 2

' t s; N (i = 1 I (Aj)2 1'1 u

=

st N-1 (49345)2 162639133 15

k. 14 l

st 4 149 pCi/11ter l Grand average - GA l H I xi i-1 r

= - - -

f GA N

49345 t

15 CA = 3290 pCi/ liter

= N0' Norraali::ed deviation from the grand 'a,verage Deviation of the mean from the grind average a D' D'=-I- - CA a 3:20 - 3290 l

O'= - 170 pCi/ liter D'

ND ' ' = -

l 3m

- 170 m

P06.1 ND' = - 0.8 i

l' l

32 l- "

l.J.-._.._.-,.. ._...~.m_.--_.._.,,,,____-.__._,,;-_____._____--._.,____,_.__--_._.__._.,......_- .

- .. m,,-

Retrieved from "https://kanterella.com/w/index.php?title=ML20099K272&oldid=2779015"