ML20211M382

Forwards Correspondence Which Documents Proposed Changes to NPDES Permit IL0048313,per Section 3.2 of App B of FOLs NPF-37 & NPF-66

ML20211M382
Person / Time
Site:	Byron
Issue date:	10/06/1997
From:	Kofron K COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BYRON-97-0226, BYRON-97-226, NUDOCS 9710140177
Download: ML20211M382 (8)

Text

Onnnionwcahh rdison onnp.in) 15)ron Gener t ng Stadon J450 North CittinJn church Road ll) ton. IldilOf 09794 101 HI 42.4 4-% 4 il October 6,1997 LTR:

BYRON 97-0226 FILE:

2.09.0410 U.S. Nuclear Regulatory Commission Document Control Desk Washington D.C. 20555-0001

Subject:

Modification to NPDES Permit No. ILOO48313 Byron Station Units 1 and 2 NPF-37/66; NRC Docket Nos. 50-454/455 Commonwealth Edison Company (Comed) is the holder of National Pollutant Discharge Elimination System (NPDES) Permit No. ILOO48313 for Byron Station.

Section 3.2 of Appendix B (Environmental Protection Plan) of Facility Operating Licenses NPF-37 and NPF-66 requires that proposed changes to the effective NPDES permit be reported to the NRC when they are submitted to the permitting agency.

Comed requested modifications for Byron Station's NPDES permit, as documented on the attached letter from J.P. Smith (Comed) to S.F. Nightingale (IEPA) dated September 29,1997.

Please address any comments or questions regarding this matter to this office.

K.L. Kofr Station Manager Byron Nuclear Power Station KLK/LUrp l

Attachment cc:

A. B. Beach, Regional Administrator - Region 111 G. F. Dick, Byron Project Manager - NRR S. D. Burgess, Senior Resident Inspector - Byron 140*'1 M. T. Lesniak, Nuclear Licensing Administrator

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September 29,1997 CERTIFIED M All.

Mr. Stephen F. Nightingale, P.E.

Manager, industrial Unit, Permit Section Division of Water Pollution Control lilinois Environmental Protection Agency 1201 North Grand Avenue East P.O. Ilox 19276 Springfield, Illinois 62794-9276

Subject:

addendum to Proposed Permit Modification. Ilyron Generating Station.

NPDES Permit No. ILOO48313.

Dear Mr. Nightingale:

Please note the following material concerning the NPDES permit modification request for Comed's llyron Station. This information is in addition to the original permit modification request submitted on June 11,1996 (see attached).

During early and late winter, when the Rock River in front of the river screen house is free ofice, conditions are conducive for the formation of underwater frazil ice. Frazil ice has the potential of partially blocking the flow of river water into the circulating water and service water makeup pump bays. Ifintake bay water levels drop low enough, the circulating makeup pumps can cavitate. Losing the circulating water makeup pumps will cause cooling tower flume levels to drop, and eventually result in plant shutdown due to loss of the circulating water system.

To prevent this from occurring, the station proposes to route a portion of cooling tower blowdown to the front of the intake bar grills. This would be accomplished by installing a header pipe with a series of nozzles in front of the outside inlet of the bar grills, to mix warmer blowdown water with the incoming river water. This system would only operate intermittently during times when circulating water makeup pumps are in operation resulting in the immediate withdrawal of warm water back into the station. Flow rate of this ice melt water will be dependent on cooling tower blowdown flowrate and will range from about 1200 gpm to 3200 gpm.

Please note that several Comed generating stations already have the ability to route a portion of discharge water back into their intake systems as a means of controlling ice formation, and have no NPDES restrictions placed on these operations.

s i nnono omnam

4 September 29,1997 Mr. Stephen F. Nightingale, P.E.

Page 2.

Secondly, we wish to add two additional sub-wastestreams to the permit. The first consists of condensate water from chiller coils at the station. This is water that collects on the outside of chiller cooling coils and is directed to the station's wastewater treatment system via the Fire & Oil sump. No additives are added to this wastestream. This sub-wastestream would be added to Outfal1001(c)- Wastewater Treatment Plant Efnuent, and could be called " Chiller coil condensate", with a llow listed as " Intermittent".

The second sub wastestream consists of generic metal cleaning activities at the station:

l both those that use water and those that use non-chelating chemicals (such as acids).

These activities have been part of station operations since the plant's inception, however, in an effort to be more complete in the listing of sub-westestreams, we suggest this be added as a sub-wastestream to Outfalls 001(c)- Wastewater Treatment Plant Efnuent:

001(d)- Radwaste Treatment System Discharge; and. 00l(e)- Stormwater Runoff Basin.

Speci0cally, this sub wastestream could be called " Generic metal cleaning discharge" with an approximate flow listed as " Intermittent".

Lastly, in our meeting held with you and Bob Mosher on February 3,1997, we informed you that we were uncertain as to whether use of a mixing zone to meet the water quality standard for boron relative to discharge from Outfall 001(d), needs to be formally recognized in a station's NPDES permit. Using the default mixing zone calculation in

" Illinois Permitting Guidance for Mixing Zones" dated April 23,1993, along with published 7Q10 streamuow for the Rock River, we calculated that the target baron enluent concentration in Byron Station's blowdown should be no more than 13.08 ppm to meet the I ppm limitation at the edge of the mixing zone (see attached).

Sampling conducted on Byron's Cooling Water Blowdown (Outfall 001) over a six week period last spring indicated that the boron concentration in the blowdown was less than 2 ppm, which is well below the 13.08 calculated target efnuent concentration. A review of historical station operation has shown that the facility rarely, if ever, has discharged more than three radwaste release tanks (Outfall 00ld) per day. The station could theoretically release three release tanks with 2500 ppm boron, each, in a 24-hour period, and still meet the target efnuent concentration (see attachment). Discussions with station personnel have revealed that release tank boron concentrations are normally below 1000 ppm, and only rarely approach 2000 ppm (mainly during unit start-up or shutdown for short periods of time).

September 29,1997 Mr. Stephen F. Nightingale, P.E.

Page 3.

Again, we wish for these issues to be considered along with those outlined in our June 6 1996 correspondence to the Agency, if you have questions or comments concerning this request, please contact me at (312) 394-4461.

Sincerely, f f

' g)'

(ful du Douglas W. Yowell Principal Biologist f

['

Approved i,

k} Jeffrey P. Smith Supervisor of Water Quality dy/bg byrmod97. doc Attachments cc:

Mr. Robert Mosher, Plad..g Section, DWPC, IEPA Mr. Blaine Kinsley, industrial Permits Section, DWPC, IEPA o

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3 June i1,1996 CERTIFED MAIL Mr. Stephen F. Nightingale, P E.

Manager, industrial Unit, Permit Section D; vision of Water Pollution Control lilinois Environmental Protection Agency 2200 Churchi4 Road P O. Box 19276 Springfield, Illinois 62794-9276

Subject:

Proposed Permit Modification, Byron Generating Station P9ES Permit No.

ILOO48313

Dear Mr. Nightingale:

Comed received a year-round fecal coliform disinfection exemption from the Agency on February 14,1996. Therefore, we respectfully request Byron Station's NPDES permit be modified to reflect this exemption. Specifically, the permit would require modification to remove the fecal coliform sampling requirement for Outfal1001(b) - Sewage Treatment Plant Efiluent, and removal of Special Condition 5. relative to fecal coliform.

Secondly, on March 16,1996, Comed submitted notification to the Agency relative to intermediate levels of hydrazine discharged at Byron Station during unit outages. Since Byron Station's NPDES permit currently only applies hydrazine monitoring requirements relative to a particular station operation, i.e., during the discharge of steam generator cleaning and rinse water (historically, steam generator lay-up solution), it may be more prudent to base hydrazme monitoring requirements based on actual concentrations of hydrazine in water being discharged, regardless of the station operation that results in the discharge of hydrazme above levels seen during normal unit operation. Such a requirement would serve to ensure that the narrative and/or applicable hydrazine water quality limits are being met in discharges from Byron Station.

For instance, Special Condition 12 could be clarified relative to hydrazine discharges at Byron Station. Specifically, this condition could be reworded to include an "acthe level" whereby the station would conduct hydrazine monitoring in cooling system blowdown discharges to the Rock River once a certain hydrazine threshold level is reached in any process wastewater discharged to the cooling system, regardless of the process that generates the water. We would be glad to offer the Agency suggested language for consideration.

s i nn,m i..mpam

9 June 11,1996' Mr. Stephen Nightingale. P.E.

Page 2.

Lastly, as you may be aware, USEPA has proposed a change involving 40 CFR Part 136 methodology relative to the measurement ofoil and grease (O&G). This change, from the current Freon extraction method to one utilizing hexane extraction will likely involve

. cumbersome and costly requirements for our stations. In many cases, these facilities will have to perform upgrades to existing station laboratory equipment (explosive-proof hoods, etc.), or contract with off-site lab facilities to conduct these analyses. Both of these options will result in increased costs to the facility at a time when these same facilities are being asked to control costs due to impending deregulation of the industry.

Therefore, we request that the O&G sampling frequency be reduced for the outfalls that require sampling this parameter. Specifically, due to the excellent compliance histories associated with this parameter (see attached historical O&G data), we ask that the sample frequency for O&G at Outfalls 001(c) and 00l(d) be reduced from the cu. rent schedule of 1/ week to 1/ month. Additionally, we request that the O&G sampling frequency for Outfall 001(c) be reduced from 2/ month to quarterly (1/3 months).

If you have questions or comments concerning this request, please contact Mr. Doug Yowell of my staff at (312) 394-4461.

Sincerely, f

Iam Jeffrey P. Smith Supervisor ofWater Quality JS/DY/dc tmmod4 cc:

Mr. Robert Mosher, Planning Section, DWPC, EPA Mr. Blaine Kinsley, Industrial Permits Section, DWPC, EPA F

= _ _

t Byron Station I

ElistoricalOil& Gerase Data OutfaH 001(c)- Wastewater Treat. Plant Eff.

Outfan 001(d) Raoweste Treat. Sys.

Outfaa 001(e) Stonn water runoff pond f

i Fkm(MGD)

O&G Flow (MGD)

O&G Row (MGD)

O&F_

l Month sva max avn max ava max ave max avn max avn max

[

Jan-94 0.045 0.079 1

1 0.028 0051

< 1.25 2

Feb-94 0.058 0.118 1

1 0 028 0 053 1

1 0 225 0375 1

1 l l

Mar-94 0 U39 0.071 1.1 1.4 0 026 0 026

<22 7

0 046 0119 1

1 Apr-94 0 043 0.075 1.1 1.4 0.023 0 051, < 2.3 5

0.14 0.486 37 63 l

May-94 0 035 0.073 1

1 0028 0.051 1

1 0027 0131

_9 4 17 2 l

Jun-94 0.044 0.064 1.2 1.4 0 029 0.053

< 1.2 2

0 014 ; O724 d4 14 7

(

Jul-94 0.052 0.078 1

1 0.028 0.052

< 1.1 1.5 0 082 l 0395 5.5 9

Aug-94 0 041 0.063 2

4 0027 0.053

< 2 4

0244 0905 53 65 l

Sep-94 0.04 0 06 1

1 0.033 0.054

< 1.3 2

0 269 0 985

< 12 16 i

Oct-94 0.042 0 07 1

1 0.036 0.053 2.8 63 0 253 0895

< 18 26

}

P4 ri-94 0.038 0.063 1

1 0 03 0.053

< 3.1 7.1 0.195 0926 16 2.1 t

Dec-94 0 039 0.068 1.4 3.8 0.026 0.027

< 1.4 38 0.163 0 712

< 18*

26 l

1.1 1.6 0 032 0 052

< 1.1 13 0 142 0 524

< 2.1 3.1 l

Jan-95 0 038 K063 Feb-95 0 041 0.067 1.9 5.4 0.033 0.052

< 2.8 7.2 0 001 0.001 1

1 Mar-95 0 038 0.06 1

1 0 033 0 053

< 2.6 6

0 065 0 25 3.2 49 Apr-95 0.041 0.063 1

1 0 026 0.051

< 1.5

2. 8

• O278 0.73 1

1 I

May-95 0.05 0.13 1

1 0 028 0 052

< 4 08 12.4 0 244 0 801 4 33 4.76 t

Jun-95 0 042 0 068

< 1.43 2.5 0026 0.052 1

1 0.17 0 36 11.2 17.7 l

Jul-95 0.041 0 077 1.2 3

0.028 0.052 1

1 0 082 0 315 46 8

i Aug-95 0 046 0116 1

1 0 032 0 053 1

1 0 25 0 72 3 11 4.1 Sep-95 0 033 0.057 1.2 2.1 0 031 0.053

< 1.2 17 0 089 03

< 1.8 2.5_

Oct-95 0 045 0.07 1.4 3

0.026 0027

< 1.2 1.9 0407 1.71 1.7 1.6 j

Nov-95 0.036 0.056 2

38 00?6 0.052

< 2.4 4.3 0 436 1.194 1

1 Dec-95 0.046 0.06

< 2.4 3.8 0 024 0.027

< 1.7 37

~

Jan-96 0.045 0.079 1

1 0.028 0.051

< 1.25 2

Feb-96 0 058 0.118 1

1 0.026 0.053 1

1 0 225 0.375 1

1 Mar-96 0.039 0.071 1.1 1.4 0.026 0.026

< 2.2 7

0.046 0.119 1

1

(

I Apr-96 0.043 0.075

< 1.1 1.4 0 029 0.051

< 2.3 5

0.14 0 486 3.7 63 i

May-96 0 035 0.073 1

1 0.028 0.051 1

1 0.027 0131 94 17.2 Avg.=

0.043 0.076 1.2 1.9 0.029 0.048 1.7 36 0.147 0.506 3.1 4.8 i

Max.=

0 058 0.13 2.4 5.4 0 036 0.054 4.1 12 4 0 436 1 71 11 2 17.7 I

t

4 Syr:n Station Default Mining Zone Cr.lculation for Boron IEPA's Default Mixing Zone Equation =

C, a Ca(Og.+0 )-CugOdO, l

Ce e target effluent concentration -

Ces = target downstream concentration after mixing. For Bore. = 1 ppm 0vs = 25 % af 7010 streamflow. For Rock River,7010 = 1197 cfs. 25 % = 299.25 cfs Og a design average discharge rate. For this calculation. this value = 22.3 cfs ('0.000 gpm), which is the minimum blowdown fiow allowed by station procedure during a release tank discharge Cus " long term background concentration of a parameter (for boron. (per ' EPA): e use 0.1 ppm from permit renewelintake data) l thirefore:

C. =(1*(299 25+22.3)-(299 25*0.1))/22.3 13 08 target effluent boron concentration in blowdown

=

Tank Conc, Releaso Blowdown 1 tank per day 9 25,000 gallons each mg/L Rate, gpm Rate, gpm Ce, mg/L 2500.00 17.36 10000 4.34 2000 00 17.36 10000 3.47 1500.00 17,36 10000 2.60 1000 00 17.36 10000 1.74 500 00 17.36 10000 0.87 Tank Conc, Release Blowdown 2 tank per day @ 26,000 gallons each mg/L Rate, gpm Rate gpm Ce, mg/l.

2500.00 34.72 10000 8.68 2000.00 34.72 10000 6.94 1500 00 34.72 10000 5.21 1001 00 34.72 10000 3.47 500 00 34.72 10000 1.74 Tank Conc, Release Blowdown 3 tank per day 9 26,000 gallons each mg/L Rate, gpm Rate, gpm Ce, mg/L 2500.00 52.08 10000 13 02 2000.00 52.08 10000 10.42 1500.00 52.08 10000 7.81 1000.00 52.08 10000 5.21 500 00 52.08 10000 2.60

.