0CAN059902, Corrected Pages to 1998 Annual Radiological Environ Operating Rept
| ML20209C460 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/31/1998 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20209C451 | List:
|
| References | |
| 0CAN059902, CAN59902, NUDOCS 9907090309 | |
| Download: ML20209C460 (3) | |
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Attachment to
- OCAN059902 Page 7 of 101 Summary The Annual Radiological Environmental Operating Report presents data obtained through analyses of environmental samples collected for Arkansas Nuclear One's (ANO's)
Radiological Environmental Monitoring Program (REMP) for the period January 1,1998 through December 31,1998. This report fulfills the requirements of ANO Unit 1 Technical Specification 6.12.2.5 and Unit 2 Technical Specification 6.9.4.
During 1998, as in previous years, ANO detected radionuclides attributable to plant operations at the discharge location (Station 8). ANO personnel routinely monitor results from this area in order to note any trends. Their review of results from this area indicates the following:
Tritium levels in the surface water media continue to be well below regulatory limits.
Cobalt-60, Cesium-134 and Cesium-137 levels in the sediment media are not demonstrating any increase in comparison to previous years. Review indicates that 1998 levels are less than that of the historical average and also well below regulatory limits.
Tritium at background levels was detected in the Station 10 intake surface water control l location and the Ouita control (Station 33) and Stewart indicator (Station 32) groundwater locations. Levels detected were similar to previous background measurements.
Cesium-137, attributable to fallout from previous atmospheric weapons testing, was detected at the intake indicator (Station 10) and Piney Creek control (Station 16) sediment sample locations. However, the levels detected were well below the historic average. Section 2.0 of this report discusses these results in more detail.
Radiolonical Environmental Monitorine Proeram Radiation and radioactivity are monitored around ANO within a 22-mile radius. The REMP was established prior to the station becoming operational (1974).
This preoperational l
program provided data on background radiation and radioactivity that is normally present in j
the area. ANO has continued to monitor the environment by sampling air, milk, water, food l
products, vegetation, sediment and fish, as well as measuring radiation directly. Samples are collected from both indicator and control locations. Indicator locations are expected to show any increases or buildup of rr.dioactivity that might occur due to station operation. Control locations are further from the station and are expected to indicate the pre ence of only nr.turally occurring radioactivity.
The results obtained from indicator locations are compared with control beations and with concentrations present in the environment before the station became operational. This allows for assessment of any impact the operation of ANO might have had on the surrounding environment.
9907090309 990630 PDR ADOCK 05000313 R
m Attachment to OCAN059902 Page 40 of101 Radionuclide L9,8 1987 - 1997 Preonerational 9
Cobalt-58
<LLD 7.5
<LLD Cesium-137
<LLD
<LLD 17.8 Other Gammas <LLD
<LLD
<LLD Tritium 2070.0 699.1 200.0 Although tritium levels showed an increase as compared to previous yeam, it was not detected during the last three quarters of 1998. Therefore, this increase was a random occurrence and is not considered representative of the historical average. In addition, the indicator sample is collected at the point where liquid radwaste effluents are discharged to the bay and prior to mixing with Lake Dardanelle. Therefore, depending on plant conditions, the potential for the presence of tritium can exist. However, it can be assumed that any activities present at the point of dischahge into Lake Dardanelle aRer mixing v ould be nondetectable due to dilution. Overall,1998 levels are similar to historic values. Therefore, the operation of ANO is having little or no impact on this pathway. Figure 2-2 presents 1998 tritium concentrations in comparison to previous years.
l l
Groundwater samples were collected quarterly from two locations and analyzed for gamma radionuclides and tritium. As in preoperational and previous operational years, gamma radionuclides remained undetectable. Tritium was detected once in both the indicator and control locations at concentrations of 334.0 pCi/l and 291.0 pCi/1, respectively. These concentrations are well below the required LLD value and are considered background. Therefore, it can be concluded that plant operations is not impacting this pathway.
2.5 Vegetation and Food Product Sample Results Vegetation and food product samples were collected when available from five locations in 1998 and analyzed for Iodine-131 and gamma radionuclides. The 1998 levels remained undetectable, as has been the case since 1989. Therefore, since levels continue to remain at background, it can be concluded that plant operations is not impacting this pathway.
2.6 Sediment Sample Results Sediment samples were collected semiannually from three locations in 1998 and analyzed for gamma radionuclides. As in previous years, radionuclides attributable to ANO were detected in the discharge sediment. However, Figure 2-3 shows that 1998 levels are below those of previous operational years. Since reporting levels for J
Attachment to
- OCAN059902 Page 99 cf101 Program Exceptions:
There were six results out of control limits (3 sigma) for accuracy in the 1998 cross-check program. Of these six out of control limit results, all were analyzed by gamma spectroscopy (5 nuclides in two matrices). Five of the results in question were in liquid cross-check samples, one in a sediment sample. Of the six results in question, three were bias high and three were bias low.
There was a single result for Mn-54 in sediment out of control limits, with a slight high bias (+1.68) trend indicated after review of only six results in the past three years. Review of the cross-check results for three years (23 results) indicated a low bias (-1.11) for Cr-51 in water, even though there were only two results out of control limits. The review alto indicated a slight high bias (+1.91) for Fe-59 in water over the same three year period. Cs-134 and Cs-137 results in water indicate no trends over the three year period.
Investigation of high bias results in the past indicated it was due to coincidence summing j
effects of Y-88 and Co-60 on the efficiency curve in the effected region. To minimize the coincidence summing effects on the efficiency curve, RBS added two additional nuclides (Mn-54 and Zn-65) to the set ofliquid calibration sources. Cross-check samples for 1998
- were not analyzed using the new nuclide mix since the new sources were not purchased until the end of 1998. New gamma efficiency curves have been established using the new nuclide mix sources, and will be used to analyze cross-check samples in 1999.
There is' no impact on past data indicated by these cross-check program exceptions.
Environmental samples are analyzed and reported with a 95% confidence level that the analytical result with its associated error encompasses the "true" value. Ninety-seven percent of RBS environmental cross-check results are within control limits for accuracy and precision.
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