ML020810274

Requested Permit Revisions - Edwin I. Hatch Nuclear Plant

ML020810274
Person / Time
Site:	Hatch
Issue date:	02/28/2002
From:	Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation
References
NPDES GA0004120
Download: ML020810274 (3)

Text

Requested Permit Revisions Edwin I. Hatch Nuclear Plant NPDES No. GA0004120 Submitted by Southern Nuclear Operating Company February 2002

Specific Revisions and Updates Requested for Permit Renewal Proposed Revisions:

1. Based on the addition of a dechlorination system at Plant Hatch, Southern Nuclear Operating Company (SNC) requests that residual oxidant monitoring (TRC, FAC, TRO, and FAO) for outfalls 01 and 02 only be required when the dechlorination system is not in service. The dechlorination system neutralizes oxidant residuals in the plant service water (PSW) system in addition to the circulating water system. During times of PSW treatment, the PSW system is aligned as makeup to the circulating water system, which subjects it to dechlorination prior to discharge. A small portion of PSW (approximately 1,500 gpm) cannot be routed to the circulating water system, and is discharged directly via outfalls 01 and 02. However, excess dechlorination chemical will be provided to this portion of PSW at the discharge structure prior to being discharged to the Altamaha River.

The addition of oxidizing biocides and subsequent neutralization of oxidant residuals is strictly controlled by procedure.

2. Due to the addition of the dechlorination system, the primary route for discharge from the cooling towers is now the flume overflow (outfalls 01B and 02C) in lieu of the cooling tower blowdown.

Sampling of the flume overflow at the overflow point is not desirable nor representative of the characteristics of the outfall. The dechlorination system provides the neutralizing chemical directly at the junction of the overflow weir and discharge pipe. The neutralization chemical must have adequate mixing time and time to react prior to sampling. The discharge pipe is underground with no access point available prior to the discharge structure. SNC requests that permit requirements for outfalls 01B and 02C be modified to support compliance sampling at the combined discharge structure during times of dechlorination.

3. SNC requests removal of the requirement to document corrosion inhibitor concentrations when chiller water is drained via outfalls 01E and 02E. This requirement was placed in the previous Plant Hatch NPDES permit to facilitate trending of the inhibitor discharge by EPD to confirm water quality criteria were being met under the current Plant Hatch corrosion control program. The data collected under the expiring permit demonstrates that there is no threat to water quality criteria under the Plant Hatch corrosion control program. Collection of additional data does not appear to be warranted.

4. The current permit describes outfalls 01B and 02C as the Unit 1 and Unit 2 Cooling Tower Flume Overflow to Storm Drains, respectively. This description is incorrect. Both of these outfalls discharge directly to the Altamaha River through the main facility discharge. This error was detected by SNC after issue of the current permit. EPD was contacted and SNC was directed to annotate copies of the permit to correct the error. EPD indicated that they did not plan to issue a revision to correct this minor error. As demonstrated on the facility process flow diagram, the discharge from these outfalls is combined with other plant waste streams for ultimate discharge via outfalls 01 and

02. The following description is recommended: 01B and 02C - Cooling Tower Flume Overflow from Units 1 and 2. The new permit should reflect this change.

5. The footnote for outfalls 01B and 02C regarding the discharge of visible solids or visible foam should be removed since these outfalls do not discharge directly to the Altamaha River. Both of these outfalls are routed to the combined plant waste streams for ultimate discharge via outfalls 01 and 02.

Hatch Nuclear Plant, NPDES No. GA0004120 Page 1 of 2

6. Historical sampling data for outfalls 01E and 02E (Liquid Radwaste System) clearly demonstrates compliance with effluent limitations. SNC requests that the sampling frequency for these outfalls be reduced from twice per month to once per quarter. Past data indicates that more frequent sampling is not warranted based on consistent compliance.

7. SNC requests that the sampling frequency for outfall 01G be reduced from twice per month to once per quarter. The Neutralization Tank Low Volume Waste is utilized on an infrequent basis, and past data collected for this system demonstrates consistent compliance with all limitations.

8. SNC requests that the sampling frequency for outfall 01H - Low Volume Waste (Pressure Filter Backwash) should be reduced to once per six months. The current frequency is quarterly, and historical data demonstrates compliance with all limitations. This is an infrequent discharge which utilizes a relatively small volume of water.

9. It is requested that the description of outfall 04 be clarified to demonstrate that the discharge is routed to storm drains. SNC suggests the following description: Blowdown and Draining of Water from the Chiller Systems to Storm Drains.

10. SNC requests that Special Condition 5 in Part III of the current permit be revised to apply to both FAC/TRC and FAO/TRO. This change would make this condition consistent with language in other parts of the permit.

11. The current NPDES permit is inconsistent in the identification of the cooling tower basin drains for Units 1 and 2. The Unit 1 cooling tower basin drains have a specific outfall (OSN 01I). The Unit 2 cooling tower basin drains are incorporated into the outfall for cooling tower basin overflows (OSN 02B). SNC requests that OSN 01I be incorporated into OSN 01J (Unit 1 basin overflow) in order to be consistent with the Unit 2 outfall scheme. Both the basin overflow and basin drain go to storm drains, and they consist of the same process water. It is recommended that outfall 01I be deleted, and that outfalls 01J and 02B be renamed to Units 1 and 2 Cooling Tower Basin Overflows and Drains to Storm Drains.

Hatch Nuclear Plant, NPDES No. GA0004120 Page 2 of 2