Text

Non-ODAM Requires Sampling, Supplementary Stations for January 1, 2015 Through December 31, 2015
	ML16144A604
Person / Time
Site:	Cooper
Issue date:	05/16/2016
From:	; Teledyne Brown Engineering
To:	; Office of Nuclear Reactor Regulation
Shared Package
ML16144A611	List: ML16144A601; ML16144A604; NLS2016027, Annual Radiological Environmental Report January 1, 2015 Through December 31, 2015;
References
	Download: ML16144A604 (19)
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NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION Non-ODAM Required Sampling, Supplementary Stations 2015 Annual Report January 1, 2015 to December 31, 2015

Prepared by Teledyne Brown Engineering 2508 Quality Lane Knoxville, TN 37931-3133 1-2

TABLE OF CONTENTS I. Introduction ....................................................................................................................................... 4 II. Summary .......................................................................................................................................... 6 III. Results and Discussion of2015 Analytical Results ....................................................................... 8 A. Airborne Particulates .......................................................................................................... 9 B. Airborne Iodine ................................................................................................................... 9 C. Thermoluminescent Dosimeters ......................................................................................... 9 D. Errata Data........................................................................................................................... 9 2 1-3

APPENDICES Appendix A: Non-ODAM Required Sampling Locations .......................................................... A-1 Table A-1: Non-ODAM Sampling Station Description, Sample Type and Sample Location, Nebraska Public Power District, Cooper Nuclear Station, 2015 ........... A-2 AppendixB: Data Tables of Non-ODAM Required Sampling Locations ................................. B-1 Table B-1: Exposure Pathway- Airborne Air Particulate and Charcoal Filters ..................... B-2 Table B-2: Exposure Pathway - Airborne Composite Air Particulate Filters ......................... B-4 Table B-3: Exposure Pathway- Thermoluminescent Dosimetry............................................ B-5 3 I-4

SECTION I. INTRODUCTION 4 1-5

I. INTRODUCTION This report contains a complete tabulation of data for non-ODAM required sampling stations collected during the period January through December 2015 by Teledyne Brown Engineering- Environmental Services.

. In assessing all the data gathered for this report, it was concluded that the operation of CNS had no adverse radiological impact on the environment, and there are no known active releases into the groundwater or surface water at Nebraska Public Power District.

5 1-6

SECTION Il.

SUMMARY

6 1-7

II. Summary Data from the radiological analyses of environmental media collected during 2015 for non-ODAM required stations are tabulated and discussed below.

Radiological analyses of environmental media characteristically approach and frequently fall below the detection limits of state-of-the-art measurement methods. The "less than" values in the data tables were calculated from each specific analysis and are dependent on sample size, detector efficiency, length of counting time, chemical yield (when appropriate) and the radioactive decay factor from time of counting to time of collection. Teledyne Brown Engineering meets the Lower Limit of Detection (LLD) requirements given in Table 2 of the USNRC Branch Technical Position, Radiological Monitoring Acceptable Program (November 1979, Revision 1).

The following is a discussion and summary of the results of the environmental measurements taken during the 2015 reporting period:

7 1-8

SECTION III. RESULTS and Discussion of 2015 Analytical Results 8 I-9

III. Results and Discussion of 2015 Analytical Results A. Airborne Particulates Gross beta activity was observed in all 52 of the samples collected during 2015.

The average concentration was 0.019 pCi/m3 with a range of 0.009 to 0.039 pCi/m3

The results of the gross beta activities are presented in Table B-1. The gross beta activities for 2015 were comparable to levels measured in the previous several years. Prior to that period the gross beta activities were higher due to atmospheric nuclear weapons testing performed in other countries. The preoperational period of 1971through1974 averaged 0.098 pCi/m3 gross beta.

Air particulate filters were collected weekly and composited by locations on a quarterly basis. They were analyzed by gamma ray spectroscopy. Beryllium-7 was observed in four of the four composites. The average concentration was 0.127 pCi/m3 with a range of 0.108 to 0.140 pCi/m3. The results are presented in Table B-2. All other gamma emitters were below the detection limits.

B. Airborne Iodine Charcoal cartridges used to collect airborne iodine were collected weekly and analyzed by gamma spectrometry for iodine-131. The results are presented in Table B-1. All results were below the required lower limit of detection.

C. Thermoluminescent Dosimeters Thermoluminescent dosimeters (TLDs) determine environmental radiation doses and the results are presented in Table B-3. Ambient radiation was monitored at 26 non-ODAM required locations and collected quarterly. The quarterly average for the locations was 24.4 millirem/quarter and a range from 21.6 to 27.1 millirem/quarter. The preoperational period of 1971 through 1974 averaged 37.0 millirem/quarter. Current year TLD averages deviate from the preoperational averages due to instrument variations from previous vendors.

The data from year to year is in good agreement and indicates no adverse changes in radiation exposure to the population near the Cooper Nuclear Station.

D. Errata Data There was no errata data for 2015.

9 I-10

APPENDIX A NON-ODAM REQUIRED SAMPLING STATIONS A-1 I-11

NON-ODAM SAMPLE STATION DESCRIPTION, SAMPLE TYPE AND SAMPLE LOCATION Sample Station (a) Sample Description - Type and Location No. 111 Type: (1) Air Particulate and Charcoal Filters (2) Environmental Thermoluminescent Dosimetry Location: 10.8 miles west southwest and 1.3 miles west of Howe, Nebraska, NE~. S13, T4N, Rl3E, Nemaha County, Nebraska.

Lon. 095.84.165 W -Lat. 40.31.955 N NOl Type: (1) Environmental Thermo luminescent Dosimetry N02 Type: (1) Environmental Thermoluminescent Dosimetry N03 Type: (1) Environmental Thermo luminescent Dosimetry N04 Type: (1) Environmental Thermoluminescent Dosimetry NOS Type: (1) Environmental Thermo luminescent Dosimetry N06 Type: (1) Environmental Thermoluminescent Dosimetry N07 Type: (1) Environmental Thermo luminescent Dosimetry NOS Type: (1) Environmental Thermoluminescent Dosimetry N09 Type: (1) Environmental Thermo luminescent Dosimetry NlO Type: (1) Environmental Thermo luminescent Dosimetry Nll Type: (1) Environmental Thermoluminescent Dosimetry N12 Type: (1) Environmental Thermo luminescent Dosimetry N13 Type: (1) Environmental Thermoluminescent Dosimetry N14 Type: (1) Environmental Thermoluminescent Dosimetry N15 Type: (1) Environmental Thermoluminescent Dosimetry A-2 1-12

NON-ODAM SAMPLE STATION DESCRIPTION, SAMPLE TYPE AND SAMPLE LOCATION Sample Station (a) Sample Description - Type and Location N16 Type: (1) Environmental Thermoluminescent Dosimetry N17 Type: (1) Environmental Thermoluminescent Dosimetry N18 Type: (1) Environmental Thermo luminescent Dosimetry N19 Type: (1) Environmental Thermoluminescent Dosimetry N20 Type: (1) Environmental Thermo luminescent Dosimetry N21 Type: (1) Environmental Thermoluminescent Dosimetry N22 Type: (1) Environmental Thermoluminescent Dosimetry N23 Type: (1) Environmental Thermoluminescent Dosimetry N24 Type: (1) Environmental Thermoluminescent Dosimetry N25 Type: (1) Environmental Thermoluminescent Dosimetry A-3 1-13

APPENDIXB DATA TABLES OF NON-ODAM REQUIRED SAMPLING LOCATIONS B-1 1-14

B-1 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION EXPOSURE PATHWAY* AIRBORNE AIR PARTICULATE AND CHARCOAL FILTERS STATION NUMBER 111 COLL TIME AP FILTER CHARCOAL FILTER START STOP SAMPLE GROSS BETA 1-131 DATE DATE VOLUME UNITS (PCl/CU.M.) (PCl/CU.M.)

12/30/14 01/06/15 1.02E+04 CU.FT. 3.91 E-02 +/- 5.54E-03 L.T. 7.E-02 01/06/15 01/13/15 1.01E+04 CU.FT. 1.42E-02 +/- 3.47E-03 LT. 5.E-02 01/13/15 01/20/15 1.02E+04 CU.FT. 2.06E-02 +/- 4.01 E-03 LT. 7.E-02 01/20/15 01/27/15 9.85E+03 CU.FT. 1.26E-02 +/- 3.33E-03 LT. 6.E-02 01/27/15 02/03/15 1.01E+04 CU.FT. 1.57E-02 +/- 3.94E-03 LT. 7.E-02 02/03/15 02/10/15 1.01E+04 CU.FT. 2.81E-02 +/- 4.71E-03 LT. 6.E-02 02/10/15 02/17/15 1.00E+04 CU.FT. 2.39E-02 +/- 4.66E-03 LT. 6.E-02 to I

02/17/15 02/24/15 1.01E+04 CU.FT. 2.87E-02 +/- 4.50E-03 LT. 7.E-02 N 02/24/15 03/03/15 1.00E+04 CU.FT. 1.53E-02 +/- 3.67E-03 L.T. 4.E-02 03/03/15 03/11/15 1.15E+04 CU.FT. 1.86E-02 +/- 3.99E-03 L.T. 3.E-02 03/11/15 03/17/15 8.53E+03 CU.FT. 1.98E-02 +/- 4.47E-03 LT. 6.E-02 03/17/15 03/24/15 1.02E+04 CU.FT. 1. 72E-02 +/- 3.82E-03 LT. 5.E-02 03/24/15 03/31/15 1.00E+04 CU.FT. 1.30E-02 +/- 3. 73E-03 LT. 3.E-02 03/31/15 04/07/15 1.01 E+o4* CU.FT. 1.74E-02 +/- 3.91E-03 LT. 5.E-02 04/07/15 04/14/15 1.01E+04 CU.FT. 1.61 E-02 +/- 3.96E-03 LT. 4.E-02 04/14/15 04/21/15 9.98E+03 CU.FT. 1.32E-02 +/- 3.63E-03 LT. 4.E-02 04/21/15 04/28/15 1.01E+04 CU.FT. 1.39E-02 +/- 3.26E-03 LT. 3.E-02 04/28/15 05/05/15 1.00E+04 CU.FT. 1.84E-02 +/- 4.1 OE-03 LT. 6.E-02 05/05/15 05/12/15 1.00E+04 CU.FT. 8.99E-03 +/- 3.42E-03 L.T. 6.E-02 05/12/15 05/19/15 1.01E+04 CU.FT. 1.02E-02 +/- 3.20E-03 L.T. 6.E-02 05/19/15 05/26/15 1.02E+04 CU.FT. 1.20E-02 +/- 3.59E-03 LT. 6.E-02 05/26/15 06/01/15 9.97E+03 CU.FT. 1.32E-02 +/- 3.35E-03 L.T. 7.E-02 06/01/15 06/09/15 1.01E+04 CU.FT. 1.75E-02 +/- 3.91 E-03 LT. 5.E-02 06/09/15 06/16/15 1.01E+04 CU.FT. 1.26E-02 +/- 3.51 E-03 LT. 7.E-02 06/16/15 06/23/15 1.00E+04 CU.FT. 1.71E-02 +/- 4.06E-03 LT. 7.E-02

)--;

I

...... 06/23/15 06/30/15 1.01E+04 CU.FT. 1.33E-02 + 3.45E-03 LT. 4.E-02 Vi 06/30/15 07/08/15 1.15E+04 CU.FT. 1. 76E-02 + 3.45E-03 L.T. 1.E-02

8-1 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION EXPOSURE PATHWAY* AIRBORNE AIR PARTICULATE AND CHARCOAL FILTERS STATION NUMBER 111 COLL TIME AP FILTER CHARCOAL FILTER START STOP SAMPLE GROSS BETA 1-131 DATE DATE VOLUME UNITS (PCl/CU.M.) (PCl/CU.M.)

07/08/15 07/14/15 8.70E+03 CU.FT. 1.61E-02 +/- 4.09E-03 L.T. 2.E-02 07/14/15 07/21/15 1.00E+04 CU.FT. 1.86E-02 +/- 4.27E-03 L.T. 2.E-02 07/21/15 07/28/15 1.00E+04 CU.FT. 1.52E-02 +/- 3. 70E-03 L.T. 5.E-02 07/28/15 08/05/15 1.15E+04 CU.FT. 1.63E-02 +/- 3.54E-03 L.T. 7.E-02 08/05/15 08/10/15 7.21E+03 CU.FT. 2.14E-02 +/- 5.24E-03 .L.T. 2.E-02 08/10/15 08/18/15 1.15E+04 CU.FT. 2.26E-02 +/- 4.00E-03 L.T. 6.E-02 08/18/15 08/26/15 1.17E+04 CU.FT. 1.57E-02 +/- 3.39E-03 L.T. 3.E-02 txJ I

08/26/15 09/01/15 8.41E+03 CU.FT. 2. 78E-02 +/- 5.19E-03 L.T. 6.E-02 V.l 09/01/15 09/08/15 1.01E+04 CU.FT. 1.83E-02 +/- 3.92E-03 L.T. 6.E-02 09/08/15 09/15/15 1.01E+04 CU.FT. 2.25E-02 +/- 4.20E-03 L.T. 7.E-02 09/15/15 09/22/15 1.01E+04 CU.FT. 1.94E-02 +/- 4.1 OE-03 L.T. 4.E-02 09/22/15 09/29/15 1.02E+04 CU.FT. 2.80E-02 +/- 4.58E-03 LT. 6.E-02 09/29/15 10/06/15 1.00E+04 CU.FT. 1.07E-02 +/- 3.38E-03 L.T. 7.E-02 10/06/15 10/12/15 8.54E+03 CU.FT. 3.32E-02 +/- 5.18E-03 L.T. 7.E-02 10/12/15 10/20/15 1.16E+04 CU.FT. 1.84E-02 +/- 3.88E-03 L.T. 6.E-02 10/20/15 10/27/15 1.01 E+04 CU.FT. 2.61 E-02 +/- 4.40E-03 L.T. 6.E-02 10/27/15 11/03/15 1.01E+04 CU.FT. 2.04E-02 +/- 4.17E-03 L.T. 5.E-02 11/03/15 11/10/15 1.00E+04 CU.FT. 3.28E-02 +/- 4.87E-03 L.T. 7.E-02 11/10/15 11/17/15 1.00E+04 CU.FT. 1.78E-02 +/- 4.16E-03 L.T. 2.E-02 11/17/15 11/24/15 1.01E+04 CU.FT. 1.35E-02 +/- 3.81 E-03 L.T. 7.E-02 11/24/15 12/01/15 1.02E+04 CU.FT. 1.80E-02 +/- 3.87E-03 L.T. 6.E-02 12/01/15 12/08/15 1.00E+04 CU.FT. 3.12E-02 +/- 4.91 E-03 L.T. 7.E-02 12/08/15 12/15/15 1.01 E+04 CU.FT. t.52E-02 +/- 3.88E-03 L.T. 4.E-02 12/15/15 12/22/15 1.00E+04 CU.FT. 2.16E-02 +/- 4.16E-03 L.T. 7.E-02

-°"

I 1--'

12/22/15 12/29/15 1.01E+04 CU.FT. 2. 75E-02 +/- 4.50E-03 L.T. 7.E-02

B-2 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION EXPOSURE PATHWAY - AIRBORNE COMPOSITE AIR PARTICULATE FILTERS (PCl/CU.M.)

STATION NUMBER 111 DATE COLLECTED 12/30-03/31/15 03/31-06/30/15 06/30-09/29/15 09/29-12/29/15 GAMMA SPECTRUM ANALYSIS:

BE-7 1.27E-01 +/- 3.99E-02 1.40E-01 +/- 4.95E-02 1.33E-01 +/- 3. 70E-02 1.08E-01 +/- 5.34E-02 K-40 L.T. 5.E-02 L.T. 6.E-02 LT. 4.E-02 L.T. 7.E-02 MN-54 L.T. 3.E-03 L.T. 4.E-03 L.T. 3.E-03 LT. 5.E-03 C0-58 L.T. 6.E-03 L.T, 6.E-03 LT. 5.E-03 LT. 8.E-03 FE-59 L.T. 1.E-02 L.T. 2.E-02 L.T. 1.E-02 L.T. 2.E-02 C0-60 L.T. 2.E-03 L.T. 2.E-03 L.T. 3.E-03 L.T. 4.E-03 ZN-65 L.T. 4.E-03 L.T. 9.E-03 LT. 7.E-03 LT. 1.E-02 ZR-95 L.T. 1.E-02 L.T. 2.E-02 L.T. 8.E-03 L.T. 2.E-02 RU-103 L.T. 8.E-03 L.T. 1.E-02 LT. 7.E-03 L.T. 1.E-02 RU-106 L.T. 3.E-02 L.T. 4.E-02 LT. 2.E-02 L.T. 4.E-02 1-131 L.T. 2.E+OO L.T. 1.E+OO L.T. 1.E+OO LT. 3.E+OO CS-134 L.T. 3.E-03 L.T. 3.E-03 LT. 3.E-03 L.T. 4.E-03 CS-137 L.T. 2.E-03 LT. 3.E-03 LT. 2.E-03 LT. 4.E-03 BA-140 L.T. 4.E-01 LT. 5.E-01 LT. 3.E-01 L.T. 9.E-01 LA-140 L.T. 1.E-01 L.T. 2.E-01 LT. 2.E-01 LT. 3.E-01 CE-141 L.T. 1.E-02 L.T. 2.E-02 LT. 9.E-03 LT. 2.E-02 CE-144 L.T. 2.E-02 L.T. 2.E-02 LT. 9.E-03 L.T. 2.E-02 RA-226 L.T. 4.E-02. LT. 6.E-02 L.T. 3.E-02 L.T. 6.E-02 TH-228 , L.T. 4.E-03 L.T. 6.E-03 L.T. 3.E-03 LT. 5.E-03

8-3 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION EXPOSURE PATHWAY* THERMOLUMINESCENT DOSIMETRY* TLD COOPER NUCLEAR STATION 2015 Sample Station First Quarter Second Quarter Third Quarter Fourth Quarter Quarter Average Nuclide Number 01/01-03/31 04/01-06/30 07101-09/30 10/01-01/01 -1 S.D.

TLD 111 23.6 +/- 1.3 24.6 +/- 1.2 23.2 +/- 0.8 24.8 +/- 1.7 24.1 +/- 0.8 N01 24.7 +/- 1.9 24.7 +/- 1.1 23.3 +/- 0.6 26.0 +/- 1.5 24.7 +/- 1.3 N02 24.4 +/- 1.6 24.4 +/- 0.3 22.8 +/- 0.4 24.6 +/- 1.5 24.1 +/- 0.9 N03 23.2 +/- 0.5 24.7 +/- 0.8 24.4 +/- 0.7 25.4 +/- 0.3 24.4 +/- 0.6 N04 22.8 +/- 0.5 25.9 +/- 1.5 21.8 +/- 0.5 23.4 +/- 0.7 23.5 +/- 0.8 NOS 23.7 +/- 0.6 24.7 +/- 1.2 24.2 +/- 0.6 25.4 +/- 0.9 24.5 +/- 0.9 N06 24.4 +/- 0.6 24.2 +/- 0.4 22.4 +/- 0.3 24.9 +/- 1.7 24.0 +/- 0.8 N07 27.0 +/- 2.0 25.2 +/- 0.8 24.2 +/- 0.9 27.1 +/- 0.6 25.9 +/- 1.1 NOB 22.4 +/- 0.7 23.6 +/- 0.4 21.6 +/- 0.7 24.0 +/- 0.7 22.9 +/- 0.6 tD I

N09 23.5 +/- 0.7 23.7 +/- 0.4 22.7 +/- 0.3 24.4 +/- 1.8 23.6 +/- 0.8 U'I N10 24.9 +/- 0.5 25.2 +/- 1.5 24.0 +/- 0.9 25.3 +/- 2.1 24.8 +/- 1.2 N11 23.4 +/- 1.0 24.3 +/- 1.0 23.7 +/- 0.1 24.0 +/- 0.7 23.9 +/- 0.7 N12 24.2 +/- 0.7 25.5 +/- 1.0 25.1 +/- 0.9 26.0 +/- 0.9 25.2 +/- 0.9 N13 24.3 +/- 0.7 26.1 +/- 0.9 24.2 +/- 0.1 26.5 :!; 1.1 25.3 +/- 0.7 N14 22.9 +/- 0.7 24.3 +/- 0.6 22.8 +/- 0.8 24.8 +/- 0.7 23.7 +/- 0.7 N15 23.9 +/- 0.8 22.9 +/- 0.7 24.5 +/- 0.7 26.0 +/- 0.7 24.3 +/- 0.7 N16 23.7 +/- 0.5 25.6 +/- 0.3 23.9 +/- 0.6 25.7 +/- 0.8 24.7 +/- 0.6 N17 24.0 +/- 0.9 25.9 +/- 0.8 23.8 +/- 0.2 25.4 +/- 0.2 24.8 +/- 0.5 N18 22.6 +/- 0.4 24.0 +/- 0.5 22.9 +/- 0.5 24.4 +/- 0.7 23.5 +/- 0.5 N19 25.2 +/- 0.5 25.0 +/- 0.6 23.9 +/- 0.6 25.4 +/- 1.3 24.9 +/- 0.7 N20 25.7 +/- 0.4 26.3 +/- 0.7 23.3 +/- 1.7 26.7 +/- 0.5 25.5 +/- 0.8 N21 23.7+/-1.5 25.1 +/- 0.7 23.1 +/- 1.1 24.7 +/- 2.1 24.1 +/- 1.3

s~a NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION EXPOSURE PATHWAY - THERMOLUMINESCENT DOSIMETRY - TLD COOPER NUCLEAR STATION 2015 Sample Station First Quarter _ Second Quarter Third Quarter Fourth Quarter Quarter Average Nuclide Number 01/01-03/31 04/01-06/30 07 /01-09/30 10/01-01/01 - 1 S.D.

N22 23.6 +/- 0.6 25.1 +/- 0.9 24.3 +/- 0.7 26.1 +/- 1.1 24.8 +/- 0.8 N23 22.9 +/- 0.4 24.2 +/- 0.2 22.8 +/- 1.8 24.6 +/- 1.0 23.6 +/- 0.9 N24 25.4 +/- 0.3 26.1 +/- 0.3 25.1 +/- 0.6 27.1 +/- 0.3 25.9 +/- 0.4 N25 24.5 +/- 0.4 24.0 +/- 1.0 23.4 +/- 0.2 25.8 +/- 1.2 24.4 +/- 0.7 Average/Quarter 24.0 +/- 1.1 24.7 +/- 0.9 23.6 +/- 1.0 25.3 +/- 1.0 Range (20.6-25.3) (24.2-26.0) (24.1-27.8) (21.5-26.4)

Detection/Total 26/26 26/26 26/26 26/26

END OF DOCUMENT NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION Non-ODAM Required Sampling, Supplementary Stations 2015 Annual Report January 1, 2015 to December 31, 2015

Prepared by Teledyne Brown Engineering 2508 Quality Lane Knoxville, TN 37931-3133 1-2

TABLE OF CONTENTS I. Introduction ....................................................................................................................................... 4 II. Summary .......................................................................................................................................... 6 III. Results and Discussion of2015 Analytical Results ....................................................................... 8 A. Airborne Particulates .......................................................................................................... 9 B. Airborne Iodine ................................................................................................................... 9 C. Thermoluminescent Dosimeters ......................................................................................... 9 D. Errata Data........................................................................................................................... 9 2 1-3

APPENDICES Appendix A: Non-ODAM Required Sampling Locations .......................................................... A-1 Table A-1: Non-ODAM Sampling Station Description, Sample Type and Sample Location, Nebraska Public Power District, Cooper Nuclear Station, 2015 ........... A-2 AppendixB: Data Tables of Non-ODAM Required Sampling Locations ................................. B-1 Table B-1: Exposure Pathway- Airborne Air Particulate and Charcoal Filters ..................... B-2 Table B-2: Exposure Pathway - Airborne Composite Air Particulate Filters ......................... B-4 Table B-3: Exposure Pathway- Thermoluminescent Dosimetry............................................ B-5 3 I-4

SECTION I. INTRODUCTION 4 1-5

I. INTRODUCTION This report contains a complete tabulation of data for non-ODAM required sampling stations collected during the period January through December 2015 by Teledyne Brown Engineering- Environmental Services.

. In assessing all the data gathered for this report, it was concluded that the operation of CNS had no adverse radiological impact on the environment, and there are no known active releases into the groundwater or surface water at Nebraska Public Power District.

5 1-6

SECTION Il.

SUMMARY

6 1-7

II. Summary Data from the radiological analyses of environmental media collected during 2015 for non-ODAM required stations are tabulated and discussed below.

Radiological analyses of environmental media characteristically approach and frequently fall below the detection limits of state-of-the-art measurement methods. The "less than" values in the data tables were calculated from each specific analysis and are dependent on sample size, detector efficiency, length of counting time, chemical yield (when appropriate) and the radioactive decay factor from time of counting to time of collection. Teledyne Brown Engineering meets the Lower Limit of Detection (LLD) requirements given in Table 2 of the USNRC Branch Technical Position, Radiological Monitoring Acceptable Program (November 1979, Revision 1).

The following is a discussion and summary of the results of the environmental measurements taken during the 2015 reporting period:

7 1-8

SECTION III. RESULTS and Discussion of 2015 Analytical Results 8 I-9

III. Results and Discussion of 2015 Analytical Results A. Airborne Particulates Gross beta activity was observed in all 52 of the samples collected during 2015.

The average concentration was 0.019 pCi/m3 with a range of 0.009 to 0.039 pCi/m3

The results of the gross beta activities are presented in Table B-1. The gross beta activities for 2015 were comparable to levels measured in the previous several years. Prior to that period the gross beta activities were higher due to atmospheric nuclear weapons testing performed in other countries. The preoperational period of 1971through1974 averaged 0.098 pCi/m3 gross beta.