ML19345D999

Nonroutine 30-day Radiological Environ Event Rept:On 801110, Radioiodine Analysis Results Detected I-131 Increase in Milk Samples at Sample Stations 35 & 37.Caused by Apparent Fuel Element Leaks in Unit 2 Reactor Core

ML19345D999
Person / Time
Site:	Brunswick
Issue date:	12/09/1980
From:	Tollison A CAROLINA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
BSEP-80-2029, NUDOCS 8012220351
Download: ML19345D999 (5)

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Carohna Power & Light Company r-- . - . - - -- 3--r us Brunswick Steam Electric Plant Company Correspondence P. O. Box 10429 Southport, NC 28461 December 9, 1980 FILE: B09-13516.2 SERIAL: BSEP/80-2029 Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Co= mission Region II, Suite 3100 101 Marietta Street N.W.

Atlanta, CA 30303 BRUNSWICK STEAM ELECTRIC PLANT UNIT NOS. 1 & 2 LICENSE NOS. DPR-71 AND DPR-62 DOCKET NOS. 50-325 AND 50-324 30-DAY NONROUTINE RADIOLOGICAL ENVIRONMENTAL EVENT REPORT

Dear Mr. O'Reilly:

Results of radioiodine analysis of a weekly milk sample collected on November 10, 1980, as part of the Brunswick Steam Electric Plant's Environ = ental Radio-logical Monitoring Program, detected I-131 at a concentration of 2.12 1 0.35 pCi/ liter at Milk Sample Station No. 35. This analysis was confirmed on November 16, 1980. At Control Station No. 37, the I-131 concentration was

<0.0577 pCi/ liter. The I-131 concentration detected in this sample cons titutes a 30-day reportable event in accordance with the Erunswick Technical Specifica-tions, Appendix B, Section 5.4.2b, pertinent to environmental sampling.

The source of the I-131 is attributed predominantly to Brunswick Plant operations.

Following a Unit No. 2 reactor scram on October 29, 1980, an increase in radioactivity at the Unit No. 2 Reactor Building roof vent was noted. Sub-sequent reactor scrans on November 13, 1980, and November 18, 1980, also produced increases. The scurce of this iodine activity can be attributed to apparent fuel element leaks in the Unit No. 2 reactor core. During this period, an increase in environmental radiation levels was noted. This phe-nomenon is attributed to Chinese nuclear weapons test. A nucicar detonation is known to have occurred on October 16, 1980. A summary of plant release rates, environ = ental sa=pling data and dose projections is enclosed as an attachmegt, to this report.

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Mr. James P. O'Reilly December 9, 1980 Corrective Action.

1. Fuel sipping is planned for the next Unit No. 2 refueling outage. De-fective fuel elements will be replaced as necessary.

2. A Unit No. 2 outage is planned for December 6-11, 1980, to repair steam leaks.

3. Environmental sampling is continuing in accordance with the Technical Specifications. Sampling will be increased on an "as needed" basis.

Very truly yours, A. C. Tollison, Jr., General Manager Brunswick Steam Electric Plant AHC/j ro Enclosure cc: Mr. R. A. Hartfield Mr. V. Stello i

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. l Effluent and Environmental Data

1. Unit No. 2 Reactor Building I-131 Release Rates I-131 Release Date- '

Rate Ci/Second 10/10/80 6.66 E-11 ,

10/13/80 1.11 E-11 10/28/80 4.28 E-11 10/30/80 1.71 E-8 11/2/80 1.07 E-8 11/3/80 4.62 E-9 11/7/80 1.52 E-9 11/8/80 8.44 E-10 11/9/80 3.45 E-9 11/10/80 2.40 E-9 11/14/80 6.64 E-9 11/15/80 1.51 E-8 11/16/80 2.75 E-9 11/17/80 6.80 E-9 11/18/80 3.40 E-9 11/20/80 1.20 E-8

2. Milk Sample Results (I-131 Concentrations in pCi/ Liter)

Sample Date Statien No. 35 Station No. 36 Station No. 37 11/17/80 1.37 + 0.45

~

0.929 + 0.271 1.37 + 0.11 11/10/80 2.12 ~ 0.35* 0.437 + 0.167 <0.0577 11/3/80 0.454 + 0.259

~

<0.108- 0.481 + 0.200

~

10/27/80 <0.354 0.150 + 0.141 0.345 1 0.105

• Constitutes Reportable Item NOTE: The positive results at Sample Station No. 35 are the only results which can be attr 4 buted to Brunswick Plant operations.

Positive results at Sa=ple Station Nos. 36 and 37 are attributed i

to nuclear weapons fallout. Variations in these nu=bers are due j in part to unequal distributions of the fallout activity and different composite sampling periods for the individual milk stations (this can be significant considering the relatively

! short (eight day) half-life of I-131).

3. Air Sample Data (AC)

Date Sampled Station I-131 Concentration pCi/M 3 10/31/80 24 1.10 1 0.54 E-1 NOTE: Four additional air sample stations were sampled on this date; no detectable activity was found.

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4. Food Crop Samples (FC)

On October 31, 1980, one food crop sample of leafy vegetables was obtained approxi=ately 1.5 miles south .,f the plant. Only naturally ,

occurring radionuclides were detected.

On November 24, 1980, two food crop samples of leafy vegetables were taken at locations on the north and east site exclusion boundary. Only naturally occurring radisnuclides were detected.

5. Fodder and Feed Samples (FO)

On October 31, 1980, four fodder and feed samples were taken from locations around the plant site exclusion boundary. One sample, neo.

the plant Visitors Center, showed an activity of 2.10 1 0.37 E-1 pCi/gm(wet). This level of radioactivity does not constitute a reportable event.

On November 24, 1980, samples were taken at seven locations near the plant.

Sample No. Location ~

l Site Exclusion Boundary, near CP&L Visitors Center 2 Highway 87, one-half mile south of Visitors Center 3 Near Emergency TLD Location No. 18 4 Site Exclusion Boundary, construction access road 5 Site Exclusion Boundary, near Stevens farm 6 Site Exclusion Boundary, near PMAC Sa=ple Station 7 Site Exclusion Boundary, near Bethel Church Road Sample Data Results are in units of pCi/kg(wet)

Sample No. 1 2 3 4 5 6 7 K-40 2630 t 310 681 t 206 960 t 256 1280 t 360 Mn-54 24.3 t 14.4 81.8 t 18.4 Nb-95 1,29 ! 15, 106 t 18' Zr-93 6542 t 48 115 t 24 77 t 41.9 115 t 41 Ru-103 107 1 26 87.5 t 16.6 57.9 t 21.2 121 1 25 124 + 22 103 1 14 102 3 16 (1-131 i 76 1 20.7 54.7 1 25.4 Cs-137l 793 1 27 38.3 1 23 Ba-140 i 123 + 51 117 + 36 98 + 75.3 La-140i147 t 25 147 t 24 172 t 18 233 t 22 287 t .29 160 1 31 175 t 20 Ce-141 213 + 37 217 + 23 266 + 23 307 1 24 363 1 32 308 i 25 210 1 25

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5. (Cont'd)

On November 26, 1980, a sa=ple was taken of the grass at the Harris Energy and Environmental Center, New Hill, North Carolina. The results are as follows:

Zr-95 76.7 + 37.9 Ru-103 123 1 21 Cs-137 453 1 24.1 Ba-140 126 1 51 La-140 233 + 22 Ce-141 346 1 39 NOTE: The radioactivity in these samples is attributed to nuclear weapons fallout.

6. Dose Projections Assuming a 2.12 pCI/ liter concentration of I-131 and the NRC Regulatory Guide 1.109 milk consumption injestion dose f actor for adults, the projected dose rate is 0.025 =re=/ week. Utilizing actual consu=ption rates (determined by interviews with adults who would drink this milk) the projected dose r te is 0.0 = rem / week. (All milk from this cow has been sold to CP&L for milk analysis due to the cow going dry. The cow is dry at the present time.) These values are well within the design objectives of 10CFR50, Appendix I, and are considered insignificant.

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