ML18276A078

Exceedance of Benchmark Monitoring Requirement

ML18276A078
Person / Time
Site:	Sequoyah
Issue date:	10/01/2018
From:	Anthony Williams Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
References
TNR050015
Download: ML18276A078 (2)

Text

Tennessee Valley Authority, Post Office Box 2000, Soddy Daisy, Tennessee 37384-2000 October 1, 2018 Chattanooga Environmental Field Office Division of Water Resources 1301 Riverfront Parkway, #206 Chattanooga, Tennessee 37402-2013 -

TENNESSEE VALLEY AUTHORITY-SEQUOYAHNUCLEARPLANT-TENNESSEEMULTI-SECTOR GENERAL PERMIT (TMSP) .PERMIT NO. TNR050015, SECTOR O - EXCEEDANCE OF BENCHMARK MONITORING REQUIREMENT Storm water outfalls 1, 4, and 6 were sampled for iron during a qualifying rain event on September 6, 2018. Analyses of the samples resulted in iron concentrations which exceeded the benchmark value of 5 mg/L. The analytical results for these samples are summarized in Table 1 below.

Table 1. Total Recoverable Iron Results Storm Water Sample Date Analytical Results Analytical Benchmark Outfall Number Received by TV A Results Concentration (mg/L) (mg/L) 1 09/06/2018 09/15/18 21.5 5 4 09/06/2018 09/15/18 18.6 5 6 09/06/2018 09/15/18 9.73 5 This letter serves as the 30- and 60-day notification of benchmark exceedances for total recoverable rron.

30-Day Requirement Per the permit requirement, the areas surrounding Outfalls 1, 4, and 6 were inspected to determine the likely cause of the ex9eedances. The following potential issues were identified:

• Outfall I - This outfall is located downhill from an area where cathodic protection equipment -

is being installed as part of licensing renewal requirements at the site. Trucks entering and leaving the area created a soil disturbance which is believed to be the source of the iron exceedance.

• Outfall 4-There is a laydown yard within 50 feet of this outfall. Some of the equipment in the laydown yard has rusted. Run-off from this equipment is most likely the cause of the exceedance at this outfall.

• Outfall 6 - The iron exceedance from this outfall is most likely due to run-off from a spoils area

_temporarily being used to store hydro-excavated soil. The spoils area is approximately 200 ft from the outfall.

60-Day Requirement The Storm Water Pollution Prevention Plan (SWPPP) has been reviewed to identify changes that need to be incorporated in the plan to reduce the iron concentrations at outfalls 1, 4, and 6. The proposed changes and their corresponding timetable for completion are shown in Table 2.

T able 2 P rooosedC orrective A CtiODS and T"unetable tior C ompIetion Outfall Actions to reduce iron concentration Completion date 1 Stabilize disturbed soil around cathodic protection area by the addition of 10/31/18 stone along the driving area and by applying straw and seed to adjacent bare areas.

4 Remove rusted equipment from laydown area. Add heavy metal adsorbent 11/30/18 socks around the opening of the outfall.

6 Place additional silt fencing around the perimeter of the spoils area. Line 10/31/18 the inside of the silt fence with hay bales. Create a swale in the road leading to the spoils area to divert the flow of water from the spoils area to a grassy field.

n/a Revise SWPPP to incorporate additional BMPs at outfalls 1, 4, and 6 11/15/18 If you have questions or need additional information, please contact Millicent Garland by phone at (423) 843-6714 or by e-mail at mrmoore@tva.gov.

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best ofmy knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility offine and imprisonment for knowing violations.

cc U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555