ML12088A366

Response to NRC Request for Additional Information, Dated February 28th, 2012, Related to the License Renewal Application

ML12088A366
Person / Time
Site:	Limerick
Issue date:	03/27/2012
From:	Gallagher M Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML12088A366 (78)

Text

Michael P.GallagheT Telephone 610.765.5958 Exekrn.

Vice President Fax 610.765.5658 Nuclear License Renewal www.exeloncorp.com michaelp.gallagher@exeloncorp.com Exelon Nuclear 200 Exelon Way Ke~nnett Square, PA 19348 10 CFR 50 10 CFR 51 10 CFR 54 March 27, 2012 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Units 1 and 2 Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353

Subject:

Response to NRC Request for Additional Information, dated February 28th, 2012, related to the Limerick Generating Station License Renewal Application

References:

1. Exelon Generation Company, LLC letter from Michael P. Gallagher to NRC Document Control Desk, "Application for Renewed Operating Licenses", dated June 22, 2011

2. Letter from Leslie Perkins (NRC) to Michael P. Gallagher (Exelon), "Request for Additional Information for the review of the Limerick Generating Station, Units 1 and 2, License Renewal Application Environmental Review", dated February 28, 2012 In the Reference 1 letter, Exelon Generation Company, LLC (Exelon) submitted the License Renewal Application (LRA) for the Limerick Generating Station, Units 1 and 2 (LGS). In the Reference 2 letter, the NRC requested additional information to support the staff's review of the LRA. Enclosure A of this letter provides a cross reference index of the Staff's questions in the Reference 2 letter and the Exelon response sheets contained in Enclosure B of this letter.

Enclosure C of this letter provides hard copies of the Exelon response sheets contained in Enclosure B coupled with hardcopies of other documents requested by NRC in the Reference 2 letter.

One hardcopy document included in Enclosure C was not prepared by Exelon or its contractors (i.e., it is a "Non-Exelon" document), and Exelon did not control development of the document.

Accordingly, while Exelon believes the information in this document to be accurate and complete, we have not verified this and cannot make any specific representation as to the accuracy or completeness of this document. The first page of the document and its entry in the index (Enclosure A) are marked with the designation "Non-Exelon."

U.S. Nuclear Regulatory Commission March 27, 2012 Page 2 An information-only copy of this letter and all enclosures is being provided to the NRC License Renewal Environmental Project Manager on CD to facilitate Staff review of the information.

This letter and its enclosures contain no regulatory commitments.

If you have any questions, please contact Mr. Al Fulvio, Manager, Exelon License Renewal, at 610-765-5936.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on 327""Zol2.

Respectfully, Michael P. Gallagher Vice President - License Renewal Projects Exelon Generation Company, LLC

Enclosures:

A: Cross Reference Index B: Hard copies of Response Sheets C: Hard copies of Response Sheets plus Other Requested Documents cc: Regional Administrator - NRC Region I (w/o Enclosure C)

NRC Project Manager (Environmental Review), NRR-DLR (w/o Enclosure C)

NRC Project Manager (Safety Review), NRR-DLR (w/o Enclosure C))

NRC Project Manager, NRR-DORL Limerick Generating Station (w/o Enclosure C)

NRC Senior Resident Inspector, Limerick Generating Station (w/o Enclosure C)

R. R. Janati, Commonwealth of Pennsylvania (w/o Enclosure C)

Enclosure A Page 1 of 7 Enclosure A Cross Reference Index

Enclosure A Page 2 of 7 Designation Exelon/

Index in NRC Letter NRC Question Non-

1. dated N Qsoon 2/28/2012 Exelon Enclosure I Request for Additional Information (RAI)

Meteorology and Air Quality Please provide the associated annual air emissions (pollutant and amount) for the most recent five years of E1-1 Item 1 operation for sources that are permitted under the Exelon Limerick Generating Station (LGS) Title V Operating Permit (-VOP 46-00038).

Sections 2.9.1 and 2.9.2 of the LGS environmental report contains numerous references to weather data that was originally presented in the 1984 Environmental Report - Operating License Stage. This data is at least 28 years old. Please provide the following meteorological information from the data recorded at the primary meteorological tower (Tower 1) or provide the best available data if the requested information is not available from Tower 1. The meteorological data should include the most recent E1-2 Item 2 year for which data is available. Please provide the Exelon following information:

a. mean monthly temperatures at LGS; - complete

b. mean monthly relative humidity values for mornings and afternoons at LGS; - complete

c. mean annual rainfall and monthly rainfall distribution at LGS; and - complete

d. indicate whether channeling effects through the river valley continue to affect regional synoptic scale weather systems at LGS as indicated in Section 2.9.1 of the LGS license renewal application.

Hydrology/Water Resources Describe the current status of Delaware River Basis Commission's review/approval of the docket revision E1-3 Item 1 (docket integration) for LGS, including, as applicable, Exelon the status of any additional studies, milestones achieved, projected timeframe for issuance, etc.

Describe the current status of LGS' National Pollutant E1-4 Item 2 Discharge Elimination System (NPDES) permit renewal Exelon

(#PA0051926), including, as applicable, milestones achieved, projected timeframe for issuance, etc.

Enclosure A Page 3 of 7 Designation Exelon/

Index in NRC Letter NRC Question Non-

1. dated 2/28/2012 Exelon Provide copies of any notices of violations, nonconformance notifications, or related infractions received from regulatory agencies associated with E1-5 Item 3 NPDES permitted discharges, sewage systems, Exelon groundwater or soil contamination, including spills, leaks, and other inadvertent releases of fuel solvents, chemicals, or radionuclides (covering past five years).

Aquatic Ecology Possum Hollow Creek is downstream of the LGS power E1-6 Item 1 block. Provide any sampling or monitoring reports for Exelon aquatic species and benthos from Possum Hollow Creek.

LGS withdraws cooling water from the Schuykill River at the Schuylkill River pumphouse. The through screen E1-7 Item 2 intake velocity can influence impingement rates. Exelon Describe the through screen intake velocity for the Schuylkill River pumphouse.

Provide a description of screen clearing and maintenance activities and frequency at the Schuylkill Pumphouse and the Perkiomen Pumphouse, which are E1-8 Item 3 owned and operated by Exelon. If available, provide a Exelon description of the screen clearing and maintenance activities and frequency at the Point Pleasant Pumping Station, which is not owned by Exelon.

Zebra mussels are a non-native species that may occur within the water bodies from which LGS withdraws.

E1-9 Item 4 Describe zebra mussel monitoring and survey efforts Exelon and discuss whether LGS staff has identified zebra mussels in any of the water bodies associated with the makeup water system of LGS.

Archaeological and Cultural Resources Submit the two Exelon Gneration Company, LLC (Exelon) presentations that were provided at the audit on the status of the agreement and the path forward for El-10 Item 1 Fricks Lock Historic District. Docketing should follow Exelon guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Describe the current the status of Fricks Lock rehabilitation and mothball project. Docketing should El-11 Item 2 follow guidelines from NRC regarding sensitive cultural Exelon resources location information. When submitting cultural resources information, do not include maps or

Enclosure A Page 4 of 7 Designation Exelonl Index in NRC Letter

1. dated dtdNRC Question Non-Exelon 2/28/2012 coordinates of site location information.

Enclosure 2 References Requested for Docketing Meteorology and Air Quality E2-1 Item A. Title V Operating Permit, TVOP-46-00038, Issued Exelon December 7, 2009, and Revised February 17, 2010.

E2-2 Item B. Title V Compliance Certification Reports (2006-2010) Exelon Aquatic Ecology NAI (Normandeau Associates, Inc.). 2010a. East E2-3 Item A. Branch Perkiomen Creek Aquatic Biology Assessment Exelon XIII, 2008 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. May.

NAI (Normandeau Associates, Inc.). 2010b. East E2-4 Item B. Branch Perkiomen Creek Aquatic Biology Assessment Exelon XIV, 2009 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. July.

NAI (Normandeau Associates, Inc.). 2010c. Fish and E2-5 Item C. Benthic Macroinvertebrate Community Composition in Exelon the Schuylkill River in the Vicinity of Limerick Generating Station During 2009. February 2010.

NAI (Normandeau Associates, Inc.). 2010d. Letter from Normandeau Associates, Inc. to Exelon Nuclear E2-6 Item D. via email. Zebra mussel/Asiatic clam Survey. Exelon November. PECO (Philadelphia Electric Company).

1984. Environmental Report - Operating License Stage. Limerick Generating Station Units 1&2. 5 vols.

RMC (RMC Environmental Services). 1984. Progress E2-7 Item E. Report, Non-Radiological Environmental Monitoring for Exelon Limerick Generating Station 1979-1983. Prepared for Philadelphia Electric Company. October.

RMC (RMC Environmental Services). 1985. Progress E2-8 Item F. Report, Non-Radiological Environmental Monitoring for Exelon Limerick Generating Station 1984. Prepared for Philadelphia Electric Company. December.

RMC (RMC Environmental Services). 1986. Progress E2-9 Item G. Report, Non-Radiological Environmental Monitoring for Exelon Limerick Generating Station 1985. Prepared for Philadelphia Electric Company. September.

Enclosure A Page 5 of 7 Designation Exelon/

Index in NRC Letter NRC Question Non-

1. dated.

2/28/2012 Exelon RMC (RMC Environmental Services). 1987. Progress E2-10 Item H. Report, Non-Radiological Environmental Monitoring for Exelon Limerick Generating Station 1986. Prepared for Philadelphia Electric Company. November.

RMC (RMC Environmental Services). 1988. Progress E2-1 1 Item I. Report, Non-Radiological Environmental Monitoring for Exelon Limerick Generating Station 1987. Prepared for Philadelphia Electric Company. September.

RMC (RMC Environmental Services). 1989. Progress E2-12 Item J. Report, Non-Radiological Environmental Monitoring for Exelon Limerick Generating Station 1988. Prepared for Philadelphia Electric Company. December.

Describe any aquatic surveys conducted at the Bradshaw Reservoir, the Wadesville Mine Pool and E2-13 Item K. discharge channel, Bedminster Water Processing Exelon Facility, and the Still Creek Reservoir. For example, submit for docketing the response to information need (AQ-2 from the Audit Information Needs).

Describe the frequency that water is withdrawn from the Schuylkill River compared to other sources. For E2-14 Item L. example, submit for docketing the response to Exelon information need (AQ-3 from the Audit Information Needs).

Describe the intake velocity, traveling screens, and any other operational procedures or structural designs that limits impingement and entrainment at the Point Pleasant Pumping Station on the Delaware River or at E2-15 Item M. the pumping stations on the Bradshaw Reservoir, Still Exelon Creek Reservoir, or Wadesville Mine Pool. For example, submit for docketing the response to information need (AQ-5 from the Audit Information Needs).

Describe any impingement or entrainment studies conducted at the Schuylkill Pumphouse, Perkiomen E2-16 Item N. Pumphouse, or at the intakes on the Delaware River. Exelon For example, submit for docketing the response to information need (AQ-6 from the Audit Information Needs).

Describe the extent of a thermal plume as a result of E2-17 Item 0. discharges to the Schuykill River. For example, submit Exelon for docketing the response to information need (AQ-7 from the Audit Information Needs).

In the ER, LGS stated that three species of concern were identified in the Pennsylvania Natural Diversity Index (PNDI) search for LGS license renewal.

E2-18 Item P. However, it was unclear which three species LGS Exelon identified and where the species would occur on the LGS site and at the Bradshaw Reservoir. Please state these species (AQ-8 from the Audit Information Needs).

Enclosure A Page 6 of 7 Designation Exelon/

Index in NRC Letter NRC Question Non-

1. dated Exelon 212812012 In addition, discuss the potential location of the three PNDI species of concern on the LGS site and at the Bradshaw Reservoir and Pumphouse, as discussed on E2-119 Item Q. Page 2-44 of the ER (AQ-8 from the Audit Information Exelon Needs).

Hydrology Submit the last 5-years of monthly records for site E2-20 Item A. groundwater production at all four site supply wells with Exelon outage periods identified.

E2-21 Item B. 2006 Hydrogeologic Investigations Report. Exelon Provide a summary of the results of groundwater E2-22 Item C. monitoring performed for tritium, strontium-90, and Exelon gamma-emitting radionuclides since 2006 (i.e.,

groundwater protection program reports).

NPDES permit renewal application for PA0051926 E2-23 Item D. (minus Appendices A, B and C) and the administrative Exelon completeness letter received from PA DEP Archaeological and Cultural Resources Submit the references called out in Section 2.10 of the ER for archaeological surveys and the architectural and historical analysis of the Fricks Lock Historic District E2-24 Item A. (CR-2 from the Audit Information Needs). Docketing Exelon should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Submit the 1983 letter from the SHPO/PHMC. This letter contains the SHPO findings regarding the determination of impacts to cultural resources from construction and operation of T-lines (CR-3 from the E2-25 Item B. Audit Information Needs). Docketing should follow Exelon guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Submit the list and description of the type of cultural resources that occur on the LGS site as a result of the CRGIS query (CR-4 from the Audit Information Needs).

E2-26 Item C. Docketing should follow guidelines from NRC regarding Exelon sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Enclosure A Page 7 of 7 Designation Exelon/

Index in NRC Letter NRC Question Non-

1. dated Exelon 2128/2012 Submit a summary of the cultural resources management plan to NRC. This summary should contain the table of contents, a brief overview, and a description of how and when the management plan will E2-27 Item D. be implemented (CR-7 from the Audit Information Exelon Needs). Docketing should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Terrestrial Ecology Biodiversity Evaluation of Possum Hollow Run E2-28 Item A. (completed under the direction of Exelon's Exelon Environmental Stewardship Committee).

E2-29 Item B. Blye, R. 1973. Relative Abundance of Bird Species Non-During Migration. Exelon E2-30 Item C. Exelon. 1979-1983. Limerick Generating Station Non- Exelon radiological Environmental Report.

E2-31 Item D. Exelon. 1984. Limerick Generating Station Non- Exelon radiological Environmental Report.

E2-32 Item E. Exelon. 1985. Limerick Generating Station Non- Exelon radiological Environmental Report.

E2-33 Item F. Exelon. 1986. Limerick Generating Station Non- Exelon radiological Environmental Report.

E2-34 Item G. Exelon Generation. 2010. Limerick Generating Station Exelon Wildlife Management Plan. LGS-R-086.

Wildlife Habitat Council (WHC). 2006. Site E2-35 Item H. Assessment and Wildlife Management Opportunities. Exelon 100 pp. LGS-R-278.

In relation to reference WHC (2006) above, please Item I. provide the following for the indicated Wildlife at Work Exelon Projects:

E2-36 Item L.a. Bird and bat project summary sheets, including location Exelon maps, data sheets, and notes E2-37 Item I.b. Frog project summary sheet Exelon Documented Environmental Evaluation E2-38 Item I.c. Walkdown/Assessment (for frog fence replacement) Exelon (Report AR 01183399)

Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TEA, TE-5, TE-6, E2-39 Item J. TE-7, TE-8, and TE-9. These information needs can be Exelon found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Enclosure B Page 1 of 69 Enclosure B Responses to NRC Request for Additional Information dated Feb. 28, 2012

Enclosure B Page 2 of 69 E1-1: Enclosure 1: Meteorolo-qy and Air Quality, item 1 Please provide the associated annual air emissions (pollutant and amount) for the most recent five years of operation for sources that are permitted under the Limerick Generating Station (LGS) Title V Operating Permit (TVOP 46-00038).

Exelon Response Annual Emission Inventory Production Reports are provided for the most recent five years of operation, including 2007 through 2011.

Enclosure B Page 3 of 69 El -2: Enclosure 1: Meteorology and Air Quality, item 2 Sections 2.9.1 and 2.9.2 of the LGS environmental report contains numerous references to weather data that was originally presented in the 1984 Environmental Report Operating License Stage. This data is at least 28 years old. Please provide the following meteorological information from the data recorded at the primary meteorological tower (Tower 1) or provide the best available data ifthe requested information is not available from Tower 1. The meteorological data should include the most recent year for which data is available. Please provide the following information:

a. mean monthly temperatures at LGS;

b. mean monthly relative humidity values for mornings and afternoons at LGS;

c. mean annual rainfall and monthly rainfall distribution at LGS; and

d. indicate whether channeling effects through the river valley continue to affect regional synoptic scale weather systems at LGS as indicated in Section 2.9.1 of the LGS license renewal application.

Exelon Response Data from the Monthly Reports on the Meteorological Monitoring Program at the Limerick Generating Station for the years 2007 through 2011 were compiled to provide the mean monthly temperatures, monthly relative humidity values, and mean annual rainfall and monthly rainfall distribution at LGS. The compiled meteorological data observed at the LGS Meteorological Tower (Tower 1) for the years 2007 through 2011 is provided in attachment 1.

To determine whether channeling effects through the river valley continue to affect regional synoptic scale weather system at LGS, a review of the 1984 Environmental Report - Operating License Stage (ER-OL) was conducted. As described in more detail below, the ER-OL indicates that there are no terrain features that would affect or modify synoptic scale weather systems in the vicinity of the LGS station. The report only indicates that there is a minor channeling effect of the wind direction attributed to the Schuylkill River valley. The Environmental Report - License Renewal Application (ER-LRA) reiterates that there are no terrain features that would affect or modify synoptic scale weather systems in the vicinity of the LGS station, no substantive changes to the terrain have occurred.

Section 2.3.1.1.6 of the ER-OL, Relationship Between Synoptic and Local Scale Meteorology, states "The Limerick site is situated in an inland region of rolling terrain where one would expect little local modification of synoptic scale weather systems. There are no large bodies of water near the site, and the Schuylkill River is much too small to significantly affect the local conditions. There is a slight channeling effect at low elevations in the river valley."

Data from two meteorological towers, and one satellite wind sensor, were used to analyze effects of the Schuylkill River valley. Tower 1 is the primary onsite meteorological tower, and is located 3,000 feet NNW of the reactor-turbine enclosure on high ground with a base elevation of 250 feet above Mean Sea Level (MSL). Tower 2 is located 3,000 feet SSW of Tower 1, and is lower in the river valley (base elevation of 121 feet above MSL). Additional data was collected

Enclosure B Page 4 of 69 from a Satellite Meteorological Tower located on the east side of the river valley floor. Tower 1 and 2 both had data collected at multiple levels.

ER-OL Section 2.3.2.1.1.2 discusses the effect of terrain on wind direction and speed. A comparison of annual wind direction distributions was made between Towers 1 and 2 for the period of April, 1972 through March, 1973. The wind direction distribution at the Tower 2 (river valley) 30-foot level showed "a preference for those directional sectors parallel to the river valley." The directional distributions for each tower at levels one and two are "nearly identical, indicating that winds at the middle and upper levels on Tower 2 are not affected by the underlying valley terrain."

A comparison of the wind direction distribution from the Towers I and 2 30-foot sensors was conducted for the same one-year period, and the satellite tower wind distribution was also included. The ER-OL states "An increase in the wind directions centered about the NNW and SSE sectors, the orientation of the Schuylkill River Valley, is evident when the 30-foot directional distributions from Tower 2 and the Satellite Tower are compared with the low level directional distribution at Tower 1, situated above the river valley. This effect is most prevalent during low wind speed stable atmospheric conditions during the summer months."

Synoptic scale weather is affected by large geographical features such as large mountain ranges or large bodies of water (Great Lakes or ocean). There are no large scale geographical features in the vicinity of the LGS.

Local terrain effects on weather can be seen in the presence of smaller mountain ranges or hills, and in river valleys. For example, you will see local variations in wind direction and speed due to channeling effects of the hills or valleys, and temperature variations due to cooler air pooling in valleys. As the ER-OL and ER-LRA state, the Schuylkill River valley only has minor channeling effects on the low level wind flow near the LGS.

List of Attachments

1. Compiled Data from LGS Meteorological Tower (Tower 1), Years 2007, 2008, 2009, 2010, and 2011

Enclosure B Page 5 of 69 E1-3: Enclosure 1: Hydrologv/Water Resources, item 1 Describe the current status of Delaware River Basis Commission's review/approval of the docket revision (docket integration) for LGS, including, as applicable, the status of any additional studies, milestones achieved, projected timeframe for issuance, etc.

Exelon Response The Delaware River Basis Commission (DRBC) regulates LGS water withdrawals and water use, and also places limitations on blowdown discharges from LGS, in accordance with DRBC's regulations. DRBC Docket No. D-69-210, as revised, authorizes LGS's water withdrawals from the Schuylkill River and Perkiomen Creek and discharges to the Schuylkill River subject to conditions imposed therein. LGS procedures are used to control operations in accordance with this DRBC docket and related dockets that govern water diversion from the Delaware River for use at LGS. These procedures are consistent with the DRBC-approved Operating and Monitoring Plan in effect for the LGS makeup water supply system.

On September 17, 2007, Exelon Generation submitted an application for integration and modifications of the DRBC Docket No. D-69-210. Currently, the DRBC is drafting a consolidated Docket revision (Revision No. 13) that incorporates still-relevant portions of the original Docket and its revisions (through Revision No. 12), current DRBC policies, modifications requested by Exelon Generation based on an ongoing demonstration project (see below) and LGS operating experience, and input from the Pennsylvania Department of Environmental Protection (PADEP; see below).

The DRBC's tentative schedule is to publish the draft Docket by the end of the first quarter of 2012, provide a 60-day open public comment period, conduct a public hearing on the Docket after the public comment period, provide an additional 60-day public comment period, and then prepare a proposed final Docket revision. The DRBC estimates they will issue the proposed final integrated and modified Docket revision prior to the Commissioners' vote for approval by the fourth quarter of 2012, and, if approved, the new Docket revision would be effective in 2013 and subject to periodic renewal.

Exelon Generation fully supports the DRBC activities toward issuance of the Docket revision.

The most recent meeting with DRBC to discuss the Docket revision was February 21, 2012.

Exelon Generation has presented a draft revised Operation and Monitoring Plan for DRBC review that is intended for future implementation of the Docket revision.

Exelon Generation and the DRBC maintain routine communications regarding this Docket, including annual meetings to update the DRBC on compliance with the conditions in the Docket and studies in progress. The major studies in progress are the Wadesville Mine Pool Withdrawal and Stream Flow Augmentation Demonstration Project, in progress since 2003, to which was added in 2005 the Limerick Generating Station Water Supply Modification Demonstration Project. The multiyear demonstration has been assessing consumptive use augmentation of the Schuylkill River from the Wadesville Mine Pool and Still Creek Reservoir, use of the Schuylkill River for consumptive use when its ambient temperature reaches 59 0 F, and other possible related effects (i.e., understanding effects of reducing the use of water diverted from the Delaware River, water quality effects on public water supplies, etc.)

Enclosure B Page 6 of 69 The demonstration includes water quality and biological monitoring at numerous monitoring locations established by the DRBC. The most recent annual review meeting was conducted on March 16, 2011, and the next meeting is currently scheduled for March of 2012. Since the demonstration is still ongoing (extended by DRBC through the end of 2012 or Docket revision approval, whichever comes first), updates of the demonstration are provided to DRBC and final reports have not been developed.

In addition, Exelon Generation met with the PADEP and DRBC jointly on September 25, 2011 to discuss potential conditions in the pending DRBC Docket revision and align the proposed Docket revision with NPDES permit renewal conditions.

Enclosure B Page 7 of 69 E1-4: Enclosure 1: Hydrology/Water Resources, item 2 Describe the current status of LGS's National Pollutant Discharge Elimination System (NPDES) permit renewal (#PA0051926), including, as applicable, milestones achieved, projected timeframe for issuance, etc.

Exelon Response The Pennsylvania Department of Environmental Protection (PADEP) issued the currently-effective NPDES permit (No. PA0051926, Amendment No. 2) for the LGS plant site on December 16, 2010 with an expiration date of March 31, 2011 (five years after the initial issuance date in March 2006). The permit is administratively continued pending PADEP action on Exelon Generation's timely-submitted renewal application (submitted on September 28, 2010). The current status of permit renewal is discussed below.

PADEP regulates the following activities associated with LGS under its NPDES permitting program:

• Discharges from LGS of industrial wastewater to the Schuylkill River and Possum Hollow Run;

" Discharges of storm water from the LGS plant site to the Schuylkill River, Possum Hollow Run, and Sanatoga Creek;

• Use of chemical additives;

" Thermal discharges from LGS as required by Section 316(a) of the Clean Water Act (CWA); and,

• Design and operation of the LGS cooling system intake structures as required by CWA Section 316(b).

Exelon Generation met with PADEP and DRBC jointly on September 25, 2011 to discuss proposed conditions in the pending DRBC Docket revision for LGS and align Docket revision and NPDES permit conditions.

PADEP issued a draft renewed NPDES permit on November 28, 2011, proposing conditions substantially similar to the current permit. Exelon Generation provided comments on the draft permit to PADEP on January 6, 2012.

Enclosure B Page 8 of 69 EI-5: Enclosure 1: Hydrology/Water Resources, item 3 Provide copies of any notices of violations, nonconformance notifications, or related infractions received from regulatory agencies associated with NPDES permitted discharges, sewage systems, groundwater or soil contamination, including spills, leaks, and other inadvertent releases of fuel solvents, chemicals, or radionuclides (covering past five years).

Exelon Response No NOVs or nonconformance and related regulatory notifications were received during the past 5 years for LGS.

Enclosure B Page 9 of 69 EI-6: Enclosure 1: Aquatic Ecology, item 1 Possum Hollow Creek is downstream of the LGS power block. Provide any sampling or monitoring reports for aquatic species and benthos from Possum Hollow Creek.

Exelon Response No direct sampling or monitoring for aquatic species and benthos from Possum Hollow Creek has been conducted. Therefore, no reports are available that would provide results from such activities.

Enclosure B Page 10 of 69 El -7: Enclosure 1: Aquatic Ecology, item 2 LGS withdraws cooling water from the Schuylkill River at the Schuylkill River pumphouse. The through screen intake velocity can influence impingement rates. Describe the through screen intake velocity for the Schuylkill River pumphouse.

Exelon Response As stated in Section 3.1.2.2 of the LGS LR-ER, Schuylkill River water used in the circulating water system enters the front and sides of the Schuylkill Pumphouse through vertical trash bars spaced at 8.9 centimeters (3.5 inches) on center, which allows for free passage of fish swimming near the face of the bar racks. A floating trash dock with skirt is installed in front of the trash rack to divert most surface debris and some organisms before they reach the trash racks. The pumphouse enclosure is situated adjacent to the Schuylkill River along the eastern shore and is oriented parallel to the shoreline, opposite the northern end of Limerick Island. The water then passes through four intake bays with traveling screens having 0.25-inch square mesh openings into the pump station. The three consumptive use makeup water pumps are rated at 11,300 gallons per minute (gpm) each. The two blowdown (non-consumptive use) makeup water pumps are rated at 4,000 gpm each. Any combination of pumps may be used to meet the total makeup water demand up to the current 212.7 million liters per day (56.2 million gallons per day) limit.

Also stated in Section 3.1.2.2 of the LGS LR-ER is that the Schuylkill Pumphouse is designed to limit the velocity of the water approaching the traveling screens to a maximum of 0.229 meters per second (0.75 feet per second or fps). It should be noted that this statement was based on initial design information provided during the LGS construction permit stage (in Section 3.4.3 of the LGS ER-CP) and subsequently reflected in the LGS FES-CP and ASLB Initial Decision of June 14, 1974. However, changes made to the initial Schuylkill Pumphouse design resulted in a decrease in design velocity, from 0.75 fps to 0.61 fps. This decrease is acknowledged in Section 4.2.4 of the LGS FES-OL.

Approach velocity may be used as a metric to estimate successful avoidance of the intake by aquatic organisms. Aquatic organisms with a burst swim speed greater than the approach velocity near the travelling screens are able to avoid impingement. Furthermore, aquatic organism capable of sustained swim speeds greater than the approach velocity at a given location at the entrance to and within the intake structure can avoid impingement and swim away from the intake. The multi-port entry of the intake bars and the floating skirt also provide deterrents to the aquatic organisms nearing the intake structure. The design of the Schuylkill Pumphouse relative to approach velocities has not changed from that described at the operating license stage.

Through-screen velocity has not been calculated for the LGS Schuylkill River intake since it is not the controlling factor for aquatic organism escape nor can it be readily measured.

Enclosure B Page 11 of 69 E1-8: Enclosure 1: Aquatic Ecology, item 3 Provide a description of screen clearing and maintenance activities and frequency at the Schuylkill Pumphouse and the Perkiomen Pumphouse, which are owned and operated by Exelon. If available, provide a description of the screen clearing and maintenance activities and frequency at the Point Pleasant Pumping Station, which is not owned by Exelon.

Exelon Response Perkiomen Pump Station The Perkiomen Pump Station has a passive intake system consisting of 15 submerged, stationary, wedge-wire-type screens. An air burst backwash system is provided for removal of accumulated surface debris. Typically, this system operates automatically to backwash the screen assemblies, one at a time, at preset intervals, or when water level in the wet well drops below an established set point. The time between the end of one backwash event and the beginning of the next is set at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> under good conditions. However, the time between backwash events can be set to as short as 30 minutes under bad conditions, such as during rainstorms, when heavy debris loading is expected, or under circumstances when low wet well conditions exist. If the automatic backwash system is not available, then the air burst backwash system can be operated manually.

Based on annual inspections, maintenance dredging is conducted when needed to remove sediment and debris from the Perkiomen Pump Station intake screens. Such dredging is performed in accordance with an Erosion and Sediment Control Plan and a General Permit for maintenance dredging at intake and discharge structures issued by the Pennsylvania Department of Environmental Protection. Sediment removed by the maintenance dredging contains a large stone content, and once dewatered, it is used to fill in low areas on an existing stone driveway at the Perkiomen Pump Station site.

Schuylkill Pumphouse The pumphouse enclosure is situated adjacent to the Schuylkill River along the eastern shore and is oriented parallel to the shoreline, opposite the northern end of Limerick Island. The Pumphouse includes four traveling water screens and eight trash racks. The trash racks and floating boom extend outboard from the enclosure approximately 12 feet into the channel. The structure occupies the water column from the surface down to the level of the bottom of the trash racks which are below the river channel in the immediate vicinity of the pumphouse. The bottom of the river was contoured or sloped toward the intakes when built.

Four trash rack (bar screen) panels are located on the front retaining wall with another four (two on each) on wing walls that are angled from the front wall edges back to the shoreline. The spacing on the bars is 3.5 inches, which allows for free passage of fish swimming near the screen face. A floating trash dock with skirt is installed in front of the trash rack to divert most surface debris and some organisms before they reach the trash racks.

The pumphouse has four bays, each with a vertical through-flow traveling screen. The traveling screens baskets are flow-through, each 5 feet wide with 0.25-inch square mesh clear openings

Enclosure B Page 12 of 69 using 0.080-inch wire. The traveling screens are normally operated automatically, but can be operated manually from a local control panel. In normal (automatic) operation, the screens start periodically, as set off by an exercise timer and run for a predetermined time, and then shut off.

High differential pressure levels across the screens also start the screens for a predetermined time. During automatic operation, valves open to provide wash water to the screens.

The backwash system cleans the traveling screens of debris to maintain adequate pump wetwell levels. Screen backwash water is returned to the river via NPDES Outfall 011. Leaves and debris removed on the traveling screens are collected in a dumpster and transported off site for disposal.

Sediment removal is typically performed annually to remove sediment from the pump wet wells.

Maintenance dredging is conducted when needed to remove sediment and debris in the channel in front of the intake. Such dredging is performed in accordance with a PA DEP approval for maintenance dredging at the intake. Sediment removed by the maintenance dredging is dewatered in a dredged sediment containment area inshore of the pumphouse. Any overflow discharge from the containment area is returned to the river via NPDES Outfall 012.

Point PleasantPumping Station The intake screens at the Point Pleasant Pumping Station are scheduled for cleaning four times per year-once in spring, twice in summer, and once in fall. Also, the screens must be cleaned after each large flooding event in the Delaware River. Cleanings are performed by a crew of four industrial divers. They use a high-pressure sprayer and scrub brushes to remove biological growth and algae from the wedge-wire Johnson screens. Organic debris created by the cleaning process stays in the river, all other trash is put in a dumpster for landfill disposal. After the screens have been cleaned, the divers perform a complete inspection of the intake, checking the structural integrity and reporting any known changes to the intake in comparison to previous inspections.

Enclosure B Page 13 of 69 E1-9: Enclosure 1: Aquatic Ecology, item 4 Zebra mussels are a non-native species that may occur within the water bodies from which LGS withdraws. Describe zebra mussel monitoring and survey efforts and discuss whether LGS staff has identified zebra mussels in any of the water bodies associated with the makeup water system of LGS.

Exelon Response Exelon conducts annual surveys to evaluate the presence of zebra mussel and Asiatic clam in the Schuylkill River near the Limerick Generating Station intake structure and in the Perkiomen Creek near the auxiliary intake pumphouse where flow has been augmented through a diversion of water from the Delaware River to the East Branch Perkiomen Creek via the Bradshaw Reservoir. Reports on the surveys conducted during the most recent five years of plant operation (2007 through 2011) are being provided. The reports indicate that no evidence of zebra mussel in either the Schuylkill River or the Perkiomen Creek was observed during those years.

Enclosure B Page 14 of 69 EI-10: Enclosure 1: Archaeological and Cultural Resources, item 1 Submit the two Exelon Generation Company, LLC (Exelon) presentations that were provided at the audit on the status of the agreement and the path forward for Fricks Lock Historic District.

Docketing should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Exelon Response The two Exelon Generation Company, LLC (Exelon) presentations that were provided at the audit on the status of the agreement and the path forward for Fricks Lock Historic District are provided.

As requested, the presentation by Dale Frens has been redacted to prevent disclosure of sensitive cultural resources location information. Twenty slides were affected. No redaction was necessary in the presentation by Jeannie Liggett.

In the Frens presentation, each omitted map has been replaced with a text box containing the following words: "[INSERT MAP NAME] omitted in accordance with NRC guidelines regarding sensitive cultural resources location information."

Enclosure B Page 15 of 69 E1-11: Enclosure 1: Archeological and Cultural Resources, item 2 Describe the current status of Fricks Lock rehabilitation and mothball project. Docketing should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Exelon Response The East Coventry Township, Chester County, Pennsylvania has granted Certificates of Appropriateness for the work associated with the Frick's Lock rehabilitation and mothball project, under Resolution No.'s 2011-31 and 2011-37, dated October 10, 2011 and December 19, 2011, respectively. The rehabilitation and mothball project has received Exelon funding approval, and construction activities are expected to begin in 2012. The rehabilitation and mothballing activities are specified to meet the Secretary of Interior's Standards for Rehabilitation. A perimeter fence has been constructed.

Enclosure B Page 16 of 69 E2-1: Enclosure 2: Meteorological and Air Quality, item A Title V Operating Permit, TVOP-46-00038, Issued December 7, 2009, and Revised February 17, 2010.

Exelon Response The requested document is provided.

Please note that the Pennsylvania Department of Environmental Protection issued its Comment and Response Document on February 17, 2010, and the permit was revised on March 12, 2010.

Enclosure B Page 17 of 69 E2-2: Enclosure 2: Meteorological and Air Quality, item B Title V Compliance Certification Reports (2006-2010)

Exelon Response The requested documents are provided.

Enclosure B Page 18 of 69 E2-3: Enclosure 2: Aquatic Ecology, item A NAI (Normandeau Associates, Inc.). 2010a. East Branch Perkiomen Creek Aquatic Biology Assessment XIII, 2008 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. May.

Exelon Response The requested document is provided.

Enclosure B Page 19 of 69 E2-4: Enclosure 2: Aquatic Ecology, item B NAI (Normandeau Associates, Inc.). 2010b. East Branch Perkiomen Creek Aquatic Biology Assessment XIV, 2009 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. July.

Exelon Response The requested document is provided.

Enclosure B Page 20 of 69 E2-5: Enclosure 2: Aquatic Ecology, item C NAI (Normandeau Associates, Inc.). 2010c. Fish and Benthic Macroinvertebrate Community Composition in the Schuylkill River in the Vicinity of Limerick Generating Station During 2009.

February 2010.

Exelon Response The requested document is provided.

Enclosure B Page 21 of 69 E2-6: Enclosure 2: Aquatic Ecology, item D NAI (Normandeau Associates, Inc.). 2010d. Letter from Normandeau Associates, Inc. to Exelon Nuclear via email. Zebra mussel/Asiatic clam Survey. November. PECO (Philadelphia Electric Company). 1984. Environmental Report - Operating License Stage. Limerick Generating Station Units 1&2. 5 vols.

Exelon Response In an email message dated March 23, 2012, the NRC License Renewal Environmental Project Manager clarified that NRC staff is requesting only the sections pertinent to aquatic ecology from the PECO 1984 Environmental Report - Operating License Stage.

The requested documents (NAI 2010 and aquatic excerpts from PECO 1984) are being provided.

Enclosure B Page 22 of 69 E2-7: Enclosure 2: Aquatic Ecolocqy item E RMC (RMC Environmental Services). 1984. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1979-1983. Prepared for Philadelphia Electric Company. October.

Exelon Response The requested document is provided.

Enclosure B Page 23 of 69 E2-8: Enclosure 2: Aquatic Ecology, item F RMC (RMC Environmental Services). 1985. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1984. Prepared for Philadelphia Electric Company.

December.

Exelon Response The requested document is provided.

Enclosure B Page 24 of 69 E2-9: Enclosure 2: Aquatic Ecoloq¥, item G RMC (RMC Environmental Services). 1986. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1985. Prepared for Philadelphia Electric Company.

September.

Exelon Response The requested document is provided.

Enclosure B Page 25 of 69 E2-10: Enclosure 2: Aquatic Ecology, item H RMC (RMC Environmental Services). 1987. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1986. Prepared for Philadelphia Electric Company.

November.

Exelon Response The requested document is provided.

Enclosure B Page 26 of 69 E2-11: Enclosure 2: Aquatic Ecoloqy, item I RMC (RMC Environmental Services). 1988. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1987. Prepared for Philadelphia Electric Company.

September.

Exelon Response The requested document is provided.

Enclosure B Page 27 of 69 E2-12: Enclosure 2: Aquatic Ecology, item J RMC (RMC Environmental Services). 1989. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1988. Prepared for Philadelphia Electric Company.

December.

Exelon Response The requested document is provided.

Enclosure B Page 28 of 69 E2-13: Enclosure 2: Aquatic Ecology, item K Describe any aquatic surveys conducted at the Bradshaw Reservoir, the Wadesville Mine Pool and discharge channel, Bedminster Water Processing Facility, and the Still Creek Reservoir.

For example, submit for docketing the response to information need (AQ-2 from the Audit Information Needs).

Exelon Response The Bradshaw Reservoir is an upland man-made structure, owned and operated by Exelon Generation. It is classified by the PADEP as an industrial wastewater treatment facility. As such, water quality standards do not apply within the Bradshaw Reservoir, and the NPDES Permit #PA 0052221 requires no aquatic surveys within the reservoir. Water quality limitations established in the NPDES permit apply at the outfall to the East Branch Perkiomen Creek. The Delaware River Basin Commission (DRBC) Docket No. D-79-52 CP, which approved reservoir construction and operation, also requires no aquatic surveys within the reservoir.

The Wadesville Mine, owned by Reading Anthracite Company, includes an underground reservoir or pool of water stored in a network of shafts associated with historic coal mining activities. Other than water quality testing of the mine pool discharge, as required by NPDES permits and DRBC project approval, no aquatic surveys are required for the mine pool or discharge channel. Aquatic surveys were conducted downstream (Norwegian Creek, Schuylkill River) in accordance with DRBC monitoring requirements associated with the Schuylkill River Augmentation Demonstration Project started in 2003.

The Bedminster Water Processing Facility consists of a package system that produces ozone and conveys it into a series of below ground mixing chambers to provide sufficient contact time with the water flowing through the transmission main. The water essentially flows through the facility with no aquatic component that could be surveyed.

The Still Creek Reservoir, owned and operated by the Tamaqua Borough Authority (now Tamaqua Area Water Authority) was in operation for public water supply prior to the construction of LGS. The reservoir had already been releasing water into Still Creek, which joins into the Little Schuylkill River. No aquatic surveys associated with Still Creek Reservoir releases to Still Creek were required relating to the Exelon Generation contract with TAWA for water storage and release. Aquatic surveys were conducted downstream (Little Schuylkill River) in accordance with DRBC monitoring requirements associated with the Schuylkill River Augmentation Demonstration Project started in 2003.

Enclosure B Page 29 of 69 E2-14: Enclosure 2: Aquatic Ecologv, item L Describe the frequency that water is withdrawn from the Schuylkill River compared to other sources. For example, submit for docketing the response to information need (AQ-3 from the Audit Information Needs).

Exelon Response Before 2003 (when a DRBC-sponsored demonstration project was undertaken at the request of Exelon Generation), the frequency of withdrawal from the approved sources was approximately 50% of consumptive use and 100% of non-consumptive use from the Schuylkill River, 4% of consumptive use from Perkiomen Creek natural flow, and 46% of consumptive use from Perkiomen Creek supplemented by water diverted from the Delaware River.

Since implementation of the Wadesville Mine Pool demonstration project in 2003, the frequency of withdrawal has shifted more toward the Schuylkill River, a trend that is expected to continue into the future, predicated on DRBC approval of LGS's docket revision. The percent of the time that consumptive use water will be withdrawn from the Schuylkill River in the future has not been quantified, but is expected to be greater compared to the pre-demonstration project years.

Enclosure B Page 30 of 69 E2-15: Enclosure 2: Aquatic Ecology, item M Describe the intake velocity, traveling screens, and any other operational procedures or structural designs that limit impingement and entrainment at the Point Pleasant Pumping Station on the Delaware River or at the pumping stations on the Bradshaw Reservoir, Still Creek Reservoir, or Wadesville Mine Pool. For example, submit for docketing the response to information need (AQ-5 from the Audit Information Needs).

Exelon Response The Point Pleasant Pumping Station intake (owned and operated by Forest Park Water Authority) consists of two rows of fixed cylindrical wedge-wire screens placed in deep water near mid-channel in the Delaware River. Each row contains 12 screens with each screen sized at 40-inches diameter and 80-inches of total screened length. The size of the screen openings is 2 millimeters. As stated in Section 5.3.3.2 of the LGS Final Environmental Statement of 1984 (NRC, 1984), the average intake velocity at the maximum pumping rate of 95 mgd is 0.35 feet per second.

The Bradshaw Reservoir Pumping Station withdraws water from the reservoir using no designs that limit impingement and entrainment. As part of an industrial wastewater treatment facility, the Bradshaw Reservoir serves a water transfer function not intended to support aquatic biota.

The Wadesville Mine Pool is located inside the Wadesville Mine several hundred feet below grade elevation. Pumps installed in a vertical mine shaft facilitate removal of water from the mine via the pool, and there are no design features that limit impingement and entrainment.

Conditions in an underground mine pool such as at Wadesville are not conducive for aquatic life.

Water in the Still Creek Reservoir (owned and operated by the Tamaqua Borough Authority -

now Tamaqua Area Water Authority) is released by hydrostatic head through two pipelines that penetrate the dam; the water flows through an energy dissipater and into Still Creek. There is no pumping station at this facility and no design features that limit impingement or entrainment.

It should be noted that, as stated in section 2.1.2 in the LGS License Renewal Environmental Report, the Wadesville Mine Pool, Pumphouse, and discharge channel, as well as the Still Creek Reservoir and the Point Pleasant Pumping Station and combined transmission main to the Bradshaw Reservoir, are facilities and components of the LGS makeup water supply system not owned or controlled by Exelon Generation. Exelon Generation has contractual arrangements with the respective owners of these facilities for services to supply water on behalf of LGS. None of these facilities is subject to requirements applicable to cooling water intake structures for Phase II existing facilities under Section 316(b) of the Clean Water Act.

The Bradshaw Reservoir is classified by the PADEP as an industrial wastewater treatment facility (NPDES Permit PA 0052221). Hence, its pumphouse intake structure also is not subject to requirements applicable to cooling water intake structures for Phase II existing facilities under Section 316(b) of the Clean Water Act.

Enclosure B Page 31 of 69 E2-16: Enclosure 2: Aquatic Ecology, item N Describe any impingement or entrainment studies conducted at the Schuylkill or Perkiomen Pumphouse or at the intakes on the Delaware River or the East Branch Perkiomen Creek. For example, submit for docketing the response to information need (AQ-6 from the Audit Information Needs).

Exelon Response Schuylkill or Pumphouse or Perkiomen Pumphouse Impingement sampling at the Schuylkill Pumphouse was conducted starting in 1985, soon after LGS came on line, until 1988, as described in Section 3.3 of Non-Radiological Environmental Monitoring for Limerick Generating Station for 1988 (RMC, 1989).

No impingement study was performed at the Perkiomen Pumphouse due to the intake design.

The Perkiomen intake structure consists of a series of 15 fixed cylindrical slotted (wedge-wire) screens submerged at mid-stream. Each screen is sized at 24-inches diameter and 72-inches in length. The size of the screen openings is 2 millimeters. The maximum through-slot velocity is less than 0.5 feet per second. This low intake velocity combined with sufficient bypass current velocity enables fish to avoid becoming impinged on the screens.

What would be entrained at both pumphouses was inferred from in-stream biological sampling of the eggs and larvae of fish. No entrainment sampling was done to determine what was being withdrawn from the streams into the intakes.

Point Pleasant Pumping Station (Delaware River)

The Point Pleasant Pumping Station intake structure consists of two rows of fixed cylindrical wedge-wire screens placed in deep water near mid-channel in the Delaware River. Each row contains 12 screens with each screen sized at 40-inches diameter and 80-inches of total screened length. The size of the screen openings is 2 millimeters.

During the first year of post-diversion operation (1989), the presence of a relatively healthy, diverse aquatic community that was typical of large warm water rivers in the mid-Atlantic region was documented (RMC, 1990). In addition, it was determined that the amount of river flow withdrawn had resulted in negligible changes to physical habitat and flow regimes in the Delaware River. Hence, based on these conclusions and the fact that the design of the Point Pleasant Pumping Station intake structure represented state-of-the-art technology for minimizing impingement, it was determined that the likelihood of detecting effects of water withdrawal and slight river flow changes were small, and no subsequent fish sampling in the Delaware River was required. (Normandeau, 1995) [Normandeau Associates RMC Environmental Services Division, 1995. NPDES Permit PA-0052221, Aquatic Biology Assessment IV, Response to Special Condition K, PartC, Biennial Report 1993-1994 Monitoring Period. July.]

In 1990, an entrainment study by Environmental Research and Consulting, Inc. (ERC 1991.

Post-OperationalIchthyoplankton Studies for the Point PleasantPumping Station. Report

Enclosure B Page 32 of 69 prepared for County of Bucks, Pennsylvania.) documented the effectiveness of intake screens for minimizing entrainment of fish eggs and larvae. RMC (1991). [NPDES Permit PA-0052221 Aquatic Biology Assessment II, Response to Special Condition K, Part C, Report for the Second Year of Project Operation (1990). November 1991.] used the results of the entrainment study to estimate total ichthyoplankton entrainment during 1990, the first complete year of operation of the Delaware River diversion project during which maximum pumping rates were sustained.

These estimates agreed with the anticipated effects of water withdrawal on the Delaware River ecosystem based on pre-diversion ichthyoplankton monitoring. Increased mortality of fishes due to entrainment was not significant from a population dynamics view point for any species entrained. Furthermore, the low volume of flow withdrawn and the ability to provide make-up water by releases from the Merrill Creek Reservoir upstream were determined to minimize potential effects from flow regime alteration, particularly changes in water quality and habitat characteristics. Based on such conclusions, no Delaware River ichthyoplankton monitoring was conducted after 1990. [RMC Environmental Services, Ind., 1994. NPDES Permit PA-0052221 Aquatic Biology Assessment III, 1991-1992, Section 6.0, "Delaware River Ichthyoplankton, Fish, and Benthic Macroinvertebrate Studies" at page 6-1. March.]

East Branch Perkiomen Creek No impingement or entrainment studies were conducted at the East Branch Perkiomen Creek because there is no intake structure located along this stream.

Enclosure B Page 33 of 69 E2-17: Enclosure 2: Aquatic Ecology, item 0 Describe the extent of a thermal plume as a result of discharges to the Schuylkill River. For example, submit for docketing the response to information need (AQ-7 from the Audit Information Needs).

Exelon Response The response to information need AQ-7 was as follows:

Studies examining the thermal plume from LGS discharges to the Schuylkill River are identified in the LGS Environmental Report - Operating License Stage of 1984 and NRC's Final Environmental Statement of 1984.

Exelon Generation is currently conducting an updated thermal modeling analysis of the discharge from LGS to the Schuylkill River. The study relies on the Cornell Mixing Zone Expert System (CORMIX) 2 model and will produce an updated analysis for relevant scenarios to demonstrate compliance with applicable Delaware River Basin Commission (DRBC) water quality regulations. The results will support ongoing development of a revised, consolidated DRBC docket for LGS.

Updated information is provided as follows:

The cooling tower blowdown water from each unit's cooling tower is combined and discharged into the Schuylkill River through a submerged multi-port diffuser pipe, which is designed to rapidly diffuse the heat and limit the mixing zone size. Characteristics of the diffused discharge include:

" The141-foot long header is on the east channel which distributes the discharge across the entire east channel.

" There are 283 nozzles, each 1.25-inch diameter, installed 6 inches apart for rapid mixing and a rapid decline in plume centerline temperature within 50 feet.

" The nozzles are tilted approximately 200 up from the horizontal and installed 3 inches above the riverbed to provide a positively buoyant discharge near the bottom of the channel, thus utilizing the entire water column.

" The header-is slightly tilted towards the east bank (instead of the main channel), thus the thermal plume mixes with the west channel after the initial 50-foot mixing length, providing a zone of passage on the west side The NRC Final Environmental Statement (FES) for the operation of LGS states that the predicted downstream temperature rise is normally less than 2.8 'C (5 *F). Consistent with the FES statement, the Pennsylvania Department of Environmental Protection (PADEP) requires in the current LGS NPDES permit that, with respect to the thermal impact of the discharge, the effluent shall not cause more than a 5 0 F rise above the Schuylkill River ambient temperature until stream temperature reaches 87 0 F; the permit also requires no temperature rise when the ambient temperature is 87 0 F or above and the ambient temperature not to be changed by more than 2 0 F during any one-hour period.

The updated thermal modeling analysis continues in progress, with its scope developing in consultation with PADEP and DRBC.

Enclosure B Page 34 of 69 E2-18: Enclosure 2: Aquatic Ecology, item P In the ER, LGS stated that three species of concern were identified in the Pennsylvania Natural Diversity Index (PNDI) search for LGS license renewal. However, it was unclear which three species LGS identified and where the species would occur on the LGS site and at the Bradshaw Reservoir. Please state these species (AQ-8 from the Audit Information Needs).

Exelon Response The PNDI search for the main LGS plant site identified three organisms:

1. The Tooth-cup (Rotala ramosior), a state rare plant under jurisdiction of the Pennsylvania Department of Conservation and Natural Resources (DCNR);

2. A state threatened "sensitive species" under jurisdiction of the Pennsylvania Fish and Boat Commission (PFBC); and

3. Pizzini's cave amphipod (Stygobromus pizzinli), a state special concern species under jurisdiction of the PFBC.

The PNDI search for the Bradshaw Reservoir and Pumphouse also identified a state threatened "sensitive species" under jurisdiction of the PFBC.

Requests for further information regarding the results of the PNDI search were made by letters to the DCNR and PFBC dated January 19, 2011 (copies provided in LGS LR-ER Appendix C).

DCNR responded in a letter dated March 9, 2011 (copy provided in LGS LR-ER Appendix C),

identifying the Tooth-cup for the four transmission routes (Limerick to Cromby 230kV Transmission Line Route, Cromby to North Wales 230kV Transmission Line Route, Cromby to Plymouth Meeting 230kV Transmission Line Route, and Limerick to Whitpain Meeting 500kV Transmission Line Route).

PFBC responded in a letter dated February 11, 2011 (copy provided in LGS LR-ER Appendix C), identifying the eastern redbelly turtle (Pseudemys rubriventris,PA threatened) and a "globally rare amphipod and/or isopod species".

For species under jurisdiction of the PFBC, it is assumed that the state threatened species identified in the PNDI search is the eastern redbelly turtle and that the globally rare amphipod and/or isopod species identified in the letter is Pizzini's cave amphipod.

Therefore, the three species identified by the PNDI search are the 1) Tooth-cup, 2) eastern redbelly turtle (for both the LGS plant site and the Bradshaw facility), and 3) Pizzini's cave amphipod.

Enclosure B Page 35 of 69 E2-19: Enclosure 2: Aquatic Ecoloav, item Q In addition, discuss the potential location of the three PNDI species of concern on the LGS site and at the Bradshaw Reservoir and Pumphouse, as discussed on Page 2-44 of the ER (AQ-8 from the Audit Information Needs).

Exelon Response The PNDI search and subsequent agency consultation for the main Limerick plant identified three species:

1) The Tooth-cup (Rotala ramosior)under jurisdiction of Department of Conservation and Natural Resources (DCNR);

2) Eastern redbelly turtle (Pseudemys rubriventris)under jurisdiction of Pennsylvania Fish and Boat Commission (PFBC); and,

3) Pizzini's cave amphipod (Stygobromus pizzini) under jurisdiction of PFBC.

The PNDI search and subsequent agency consultation for the Bradshaw Reservoir and Pumphouse also identified eastern redbelly turtle (PFBC).

DCNR responded to a request for further information in a letter dated March 9, 2011, identifying the Tooth-cup and stating that it is known "in a wet wooded stretch along the west side of the Schuylkill River" along the Limerick to Cromby 230 kV Transmission Line Route and "on an exposed mud flat and sandy-cobbly shores of seasonally flooded shallows basins" along the Cromby to Plymouth Meeting 230 kV Transmission Line Route.

PFBC also responded to a request for further information in a letter dated February 11, 2011.

This agency identified eastern redbelly turtle and a globally rare amphipod and/or isopod species (i.e., Pizzini's cave amphipod) as "known from the vicinity of the project sites." While the agency provided general habitat descriptions for these taxa, it did not identify specific locations where they were historically found. As discussed in the following reports, no state- or federally-listed threatened or endangered terrestrial species were observed at or in the vicinity of the LGS plant site:

• The Annual Non-Radiological Environmental Operating Reports submitted to the NRC through 2005 in accordance with the LGS Environmental Protection Plan (PECO, 1999; PECO, 2000; Exelon Generation, 2001; Exelon Generation, 2002; Exelon Generation, 2003; Exelon Generation, 2004; Exelon Generation, 2005);

• LGS Non-Radiological Environmental Monitoring Reports, 1979-1988, reporting on cooling tower bird mortality (RMC, 1984; RMC, 1985; RMC, 1986; RMC, 1987); and

• Wildlife Habitat Council's Site Assessment and Wildlife Management Opportunities for Exelon Corporation's Limerick Generating Station (WHC, 2006).

No surveys targeting eastern redbelly turtle were performed for the Bradshaw Reservoir.

Stygonectes pizzinli, a synonym for Stygobromus pizzinii, or Pizzini's cave amphipod, was collected from the Schuylkill River between 1970 and 1976 (PECO, 1984). Unidentified Stygonectes sp. were collected in the Perkiomen Creek and East Branch Perkiomen Creek during the same time period (PECO, 1984). Unidentified Stygobromus sp. were collected in 1983 from the East Branch Perkiomen Creek (RMC, 1984) and from the Schuylkill River in 1985

Enclosure B Page 36 of 69 and 1986 (RMC, 1986; RMC, 1987). Because individuals were not identified to species, it is uncertain whether any specimen collected in 1983, 1985 or 1987 was a Pizzini's cave amphipod. Other studies performed in the mid- to late-1 980s and throughout the 2000s in the East Branch Perkiomen Creek failed to identify this amphipod genus or species (RMC, 1985; RMC, 1987; NAI, 2005, 2007, 2008a, 2008b, 2009, 2010a, 2010b). Field surveys of the benthic community in the Schuylkill River (1983, 1984, 1988, 2009) also did not find any individuals of Pizzini's cave amphipod (RMC, 1984; RMC, 1985; RMC, 1989; NAI, 2010c).

In summary, even though state records indicate that certain species listed as threatened or endangered are known to be present in the area of interest, Exelon Generation has not encountered any of these threatened or endangered species during surveys that have been conducted at or near the LGS plant site.

List of reports reviewed for state- or federally-listed threatened or endangered terrestrial species:

Exelon Generation. 2001. Letter to U.S. Nuclear Regulatory Commission. 2000 Annual Environmental Operating Report (Non-Radiological). April.

Exelon Generation. 2002. Letter to U.S. Nuclear Regulatory Commission. 2001 Annual Environmental Operating Report (Non-Radiological). April.

Exelon Generation. 2003. Letter to U.S. Nuclear Regulatory Commission. 2002 Annual Environmental Operating Report (Non-Radiological). April.

Exelon Generation. 2004. Letter to U.S. Nuclear Regulatory Commission. 2003 Annual Environmental Operating Report (Non-Radiological). April.

Exelon Generation. 2005. Letter to U.S. Nuclear Regulatory Commission. 2004 Annual Environmental Operating Report (Non-Radiological). April.

NAI (Normandeau Associates, Inc.). 2005. East Branch Perkiomen Creek Aquatic Biology Assessment VIII, 2001-2003 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. August.

NAI (Normandeau Associates, Inc.). 2007. East Branch Perkiomen Creek Aquatic Biology Assessment IX, 2004 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. July.

NAI (Normandeau Associates, Inc.). 2008a. East Branch Perkiomen Creek Aquatic Biology Assessment X, 2005 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. March.

NAI (Normandeau Associates, Inc.). 2008b. East Branch Perkiomen Creek Aquatic Biology Assessment XI, 2006 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. September.

NAI (Normandeau Associates, Inc.). 2009. East Branch Perkiomen Creek Aquatic Biology Assessment XII, 2007 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. March.

Enclosure B Page 37 of 69 NAI (Normandeau Associates, Inc.). 2010a. East Branch Perkiomen Creek Aquatic Biology Assessment XIII, 2008 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. May.

NAI (Normandeau Associates, Inc.). 2010b. East Branch Perkiomen Creek Aquatic Biology Assessment XIV, 2009 Monitoring Period. Prepared for Exelon Nuclear, Limerick Generating Station. July.

NAI (Normandeau Associates, Inc.). 2010c. Fish and Benthic Macroinvertebrate Community Composition in the Schuylkill River in the Vicinity of Limerick Generating Station During 2009. February.

PECO (Philadelphia Electric Company). 1984. Environmental Report - Operating License Stage. Limerick Generating Station Units 1&2. 5 vols.

PECO (PECO Nuclear). 1999. Letter to U.S. Nuclear Regulatory Commission. 1998 Annual Environmental Operating Report (Non-Radiological). April.

PECO (PECO Nuclear). 2000. Letter to U.S. Nuclear Regulatory Commission. 1999 Annual Environmental Operating Report (Non-Radiological). April.

RMC (RMC Environmental Services). 1984. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1979-1983. Prepared for Philadelphia Electric Company. October.

RMC (RMC Environmental Services). 1985. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1984. Prepared for Philadelphia Electric Company. December.

RMC (RMC Environmental Services). 1986. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1985. Prepared for Philadelphia Electric Company. September.

RMC (RMC Environmental Services). 1987. Progress Report, Non-Radiological Environmental Monitoring for Limerick Generating Station 1986. Prepared for Philadelphia Electric Company. November.

WHC (Wildlife Habitat Council). 2006. Site Assessment and Wildlife Management Opportunities prepared for Exelon Corporation's Limerick Generating Station. 100 pp. Illustrated.

August.

Enclosure B Page 38 of 69 E2-20: Enclosure 2: Hydrology, item A Submit the last 5-years of monthly records for site groundwater production at all four site supply wells with outage periods identified.

Exelon Response Monthly water withdrawal information for Well 1 and Well 3 (Alley Well and Batch Plant Well, respectively) is contained in the annual water withdrawal reports submitted to the Pennsylvania Department of Environmental Protection (PADEP). Annual water withdrawal reports for 2006 through 2010 are being provided.

As the LGS License Renewal Environmental Report explains, two additional active groundwater wells are located on the LGS plant site, but away from the main plant structures, and their usage is intermittent and limited to domestic purposes. Withdrawal information for these two minor wells is not recorded.

Enclosure B Page 39 of 69 E2-21: Enclosure 2: Hydrology, item B 2006 Hydrogeologic Investigations Report.

Exelon Response A redacted version of the requested document is provided. Ten figures containing sensitive security information are omitted. A place holder page is provided in the location of each omitted figure.

Enclosure B Page 40 of 69 E2-22: Enclosure 2: Hydrologv, item C Provide a summary of the results of groundwater monitoring performed for tritium, strontium-90, and gamma-emitting radionuclides since 2006 (i.e., groundwater protection program reports).

Exelon Response Copies of the Annual Radiological Groundwater Protection Program Reports for 2006 through 2010 are being provided.

1. Exelon Nuclear. 2007. Limerick Generating Station Units I and 2 Annual Radiological GroundwaterProtectionProgramReport, 1 JanuaryThrough 31 December 2006. Prepared by Teledyne Brown Engineering Environmental Services. April.

2. Exelon Nuclear. 2008. Limerick Generating Station Units 1 and 2 Annual Radiological GroundwaterProtectionProgram Report, 1 JanuaryThrough 31 December 2007. Prepared by Teledyne Brown Engineering Environmental Services. April.

3. Exelon Nuclear. 2009. Limerick Generating Station Units 1 and 2 Annual Radiological GroundwaterProtectionProgram Report, I JanuaryThrough 31 December 2008. Prepared by Teledyne Brown Engineering Environmental Services. April.

4. Exelon Nuclear. 2010. Limerick Generating Station Units I and 2 Annual Radiological GroundwaterProtectionProgramReport, I JanuaryThrough 31 December 2009. Prepared by Teledyne Brown Engineering Environmental Services. April.

5. Exelon Nuclear. 2011. Limerick Generating Station Units I and 2 Annual Radiological GroundwaterProtectionProgram Report, I JanuaryThrough 31 December 2010. Prepared by Teledyne Brown Engineering Environmental Services. April.

Enclosure B Page 41 of 69 E2-23: Enclosure 2: Hydrology, item D NPDES permit renewal application for PA0051926 (minus Appendices A, B and C) and the administrative completeness letter received from PA DEP.

Exelon Response The requested documents are provided.

Enclosure B Page 42 of 69 E2-24: Enclosure 2: Archaeological and Cultural Resources, item A Submit the references called out in Section 2.10 of the ER for archaeological surveys and the architectural and historical analysis of the Fricks Lock Historic District (CR-2 from the Audit Information Needs). Docketing should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Exelon Response The references related to the Fricks Lock Historic District called out in Section 2.10 of the ER include the following:

• Abplanalp, K. M. 2010. Historical and Architectural Survey of Frick's Lock Historic District, East Coventry Township, Pennsylvania. Report prepared for Exelon Generation Company, LLC.

• Kingsley, R.B., J.A. Robertson, and D.G. Roberts. 1990. The Archaeology of the Lower Schuylkill River Valley in Southeastern Pennsylvania. Report submitted to the Philadelphia Electric Company, Philadelphia, PA.

• Milner (John Milner Associates, Inc.). 1984b. A Descriptive Report of an Archaeological Investigation for the 220-61 Transmission Line Right-of-Way in Association With the Limerick Nuclear Generating Station, Chester and Montgomery Counties, Pennsylvania.

Report submitted to the Philadelphia Electric Company.

" O'Bannon, P. 1987. Architectural and Historical Documentation of the Frick's Lock District, East Coventry Township, Chester County, Pennsylvania. Report prepared for the Philadelphia Electric Company. John Milner Associates, Inc.

As requested, a redacted version of each reference is provided to prevent disclosure of sensitive cultural resources location information. The following list indicates the extent to which the redacted documents are affected.

" Kingsley 1990- Eleven maps removed

• Abplanalp 2010 - One map removed

" O'Bannon 1987 - One map removed

" Milner 1984b - Two maps removed; Two PA Archaeological Site Survey forms (two pages each) removed Each removed page has been replaced with a page containing the following words: "This page omitted in accordance with NRC guidelines regarding sensitive cultural resources location information."

Enclosure B Page 43 of 69 E2-25: Enclosure 2: Archeological and Cultural Resources, item B Submit the 1983 letter from the SHPO/PHMC. This letter contains the SHPO findings regarding the determination of impacts to cultural resources from construction and operation of T-lines (CR-3 from the Audit Information Needs). Docketing should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Exelon Response Section 2.10.2 of the ER mentions a letter from the Pennsylvania Historical and Museum Commission (PHMC), Bureau of Historic Preservation, which serves as the State Historic Preservation Office (SHPO), dated October 5, 1983 and included in the FES-OL (Appendix F),

which indicated that the operations of LGS would have no effect on significant historic or archaeological resources provided that archaeological surveys/mitigation were undertaken for the proposed transmission lines and provided that measures were taken to mitigate visual impacts to historic sites.

The requested document is provided.

Enclosure B Page 44 of 69 E2-26: Enclosure 2: Archeological and Cultural Resources, item C Submit the list and description of the type of cultural resources that occur on the LGS site as a result of the CRGIS query (CR-4 from the Audit Information Needs). Docketing should follow guidelines from NRC regarding sensitive cultural resources location information. When submitting cultural resources information, do not include maps or coordinates of site location information.

Exelon Response The Cultural Resources Geographical Information System (CRGIS) records two aboveground historic resources and six archaeological sites within the LGS owner-controlled area (OCA).

The two recorded aboveground historic resources could also contain associated archaeological deposits.

Archaeologqical Resources The six archaeological sites recorded in the CRGIS date to the prehistoric era. Two sites are located in upland settings to the west of the Schuylkill River. Site 36CH37 contains Late and Transitional Archaic occupations, whereas Site 36CH382 revealed a Late Archaic occupation.

Two (Sites 36MG37 and 36CH103) of the four sites on the Schuylkill River floodplain are large, multicomponent sites with occupation as early as the Middle Archaic and extending to the Late Woodland. No temporal information is available for Sites 36CH38 and 36CH364.

Geomorphological studies conducted as part of the 36CH 103 data recovery indicated that the terraces along the river within the LGS OCA are Pleistocene in age with relatively small amounts of Holocene alluvium (Wagner 1990). Thus, there is little potential for deeply buried archaeological resources.

36MG37 (Underpass Site): This is a multicomponent prehistoric site extending along the eastern terrace of the Schuylkill River. It covers an area of approximately 44 acres. It was identified as part of the Buchart-Horn (1972) study (Area IV)through informant interview and field investigation, including surface collection and systematic subsurface testing. An additional surface collection was conducted as part of the Transmission Line 220-60 Phase I survey (Zatz et al. 1984a). The site contains evidence from the Middle Archaic through Transitional Archaic periods, as well as from the Late Woodland. The PHMC Environmental Review (ER) Number associated with the site is 2003-8003-042. Eligibility for the NRHP has not been determined due to insufficient data.

36CH37 (Wharehouse Field): The site is situated in an upland setting to the west of the Schuylkill River. Temporal components reported for the site include Late and Transitional Archaic. The site was identified through collector interview and its NRHP eligibility is undetermined.

Enclosure B Page 45 of 69 36CH38 (Turkey Point House): The prehistoric site was recorded through collector interview and no information on temporal components is available. It is located on the west terrace of the Schuylkill River and covers an area of approximately 8 acres. The NRHP eligibility of the site has not been determined.

36CH103 (Fricks Lock Site): The archaeological site is prehistoric in age. It is located on the west bank of the Schuylkill River, immediately to the east of the Fricks Locks Historic District.

The site corresponds to Find Areas I and II in the Buchart-Horn (1972) survey. Information from artifact collectors suggested predominantly Archaic and Early Woodland occupations. The site was reinvestigated during archaeological survey for Transmission Line 220-61 and recommended as eligible for the NRHP (Katz et al. 1984b). Data-recovery investigations, including geomorphological studies, were conducted in the small portion of the 22-acre site (0.2 acres) subject to potential ground disturbance (Katz et al. 1984b; Kingsley et al. 1990). Despite the fact that data recovery was performed at the site, the CRGIS lists its NRHP status as undetermined.

36CH364 (Payne #1): The site is listed as prehistoric with no information on specific components. It is located just to the south of Site 36CH103 and covers an area of approximately 2 acres. NRHP eligibility is undetermined.

36CH382 (Locus 25): The site is listed as Late Archaic in age and was recorded through archaeological survey for Transmission Line 220-61 (Katz et al. 1984b). Subsurface testing was conducted but did not provide sufficient data for a NRHP eligibility determination.

Aboveqround Historic Resources The two aboveground resources overlap both spatially and in their association with the Schuylkill Canal.

Fricks Locks HistoricDistrict: The historic district encompasses 18 acres and consists of historic buildings, the Schuylkill Navigation Company's Girard Canal (circa 1820-1890), the in-filled remains of Locks 54 and 55, and the former Lock Keeper's House (O'Bannon 1987). The Fricks Lock Historic District is recorded as Key #116261 in the PHMC numbering system. The Historic District buildings, built between 1757 and 1937, form part of a cohesive farming hamlet that documents the local evolution of rural domestic and agricultural architecture in this vicinity. The site was listed on the National Register of Historic Places (NRHP) in 2003 under Criteria A and C. However, the eligibility of the district under Criterion D, for the significant information it may contain, has not been determined. In addition to historical archaeological deposits, Buchart-Horn's (1972) Find Area III, which produced prehistoric artifacts, is located within the boundaries of the Fricks Locks Historic District.

Schuylkill Navigation Company Canal: The Schuylkill Navigation Company Canal [from Locks 52-53 (Laurel Locks) to Locks 54-55 (Frick's Locks)], PHMC Key #140714 was determined eligible for the NRHP in 2003 under Criteria A (local historical significance) and C (engineering significance) (CHRS, Inc. 2003, PHC CRGIS). This 5-mile section of the canal was part of the Girard Lock, originally 17 miles long. There are several intact remnants of the canal in this NRHP-eligible linear resource. However, the canal prism (channel) and Fricks Locks Historic District are the only canal-related resources recorded within the LGS property. The locks and

Enclosure B Page 46 of 69 well-preserved portions of canal prism could provide information on construction methods. The canal has not been evaluated as an archaeological resource for NRHP eligibility under Criterion D.

Enclosure B Page 47 of 69 E2-27: Enclosure 2: Archeological and Cultural Resources, item D Submit a summary of the cultural resources management plan to NRC, This summary should contain the table of contents, a brief overview, and a description of how and when the management plan will be implemented (CR-7 from the Audit Information Needs), Docketing should follow guidelines from NRC regarding sensitive cultural resources location information.

When submitting cultural resources information, do not include maps or coordinates of site location information.

Exelon Response Cultural Resources Management Plan Table of Contents

1. P UR PO S E ............................................................................................................................ 3

2. DEFINITIONS AND ACRONYMS ................................................................................... 3

3. ROLES AND RESPONSIBILITIES ................................................................................ 5

4. PRECAUTIONS AND LIMITATIONS .............................................................................. 6

5. P LAN .................................................................................................................................... 7

6. D O C UME NTA T IO N ........................................................................................................ 11

7. R E F E R E NC E S ................................................................................................................... 11

8. ATTA C HME NTS ................................................................................................................ 12 Attachment A - Cultural Resource Environmental Review Form .......................................... 13 Attachment B - LGS Plant Site Property Boundaries ............................................................ 15 Attachment C - Perkiomen Pumphouse Property Boundary ................................................ 16 Attachment D - Bradshaw Reservoir and Pumping Station Property Boundaries .................. 17 Attachment E - Bedminster Water Processing Facility Property Boundary ............................ 18 Attachment F - LGS Plant Site Protected Area Boundary .................................................... 19 Attachment G - LGS Plant Site Recorded Cultural Resources Location Map ........................ 20 Attachment H - LGS Plant Site Archaeological Sensitivity Map ............................................ 21 Attachment I - Archaeological Sensitivity Designations for Outlying Areas ........................... 22 Attachment J - Archaeological Context and Assessment ................................................... .23 Attachment K - Historic Architecture Assessment ................................................................. 34 Attachm ent L - Notification List .............................................................................................. 37 Overview The purpose of the Cultural Resources Management Plan (Plan) is to manage known, potentially existing, or discovered archaeologically or historically significant cultural resources within the Owner-Controlled Areas (OCA) of the Limerick Generating Station, Units 1 and 2 (LGS) plant site and in the outlying properties owned by Exelon Generation Company, LLC (Exelon Generation) that are associated with LGS. The Plan also addresses possible impacts from land-disturbing activities or other actions within the OCA that could introduce new noise, air, or visual element impacts to known cultural resource outside the OCA. The Plan defines the process to be implemented whenever ground-disturbing or other activities take place that could affect cultural resources and identifies the roles and responsibilities of LGS employees within that process.

Enclosure B Page 48 of 69 The Plan includes four components:

• Procedures to be implemented when ground-disturbing activities are to be undertaken

• Procedures to be implemented when a planned activity will introduce new noise, air, or visual elements to areas outside the OCA

" Procedures to be undertaken when cultural resources are discovered while performing a land-disturbing activity

" Procedures to verify that recorded cultural resources have not been adversely affected by human activity Culturally protected areas within the OCA and outlying properties are identified and exhibited as attachments to the Plan.

Implementation The Plan is implemented through (1) the LGS design input and configuration change impact screening process, (2) the LGS procedure applicable to excavation activities, and (3) LGS guidance for the completion of environmental tasks.

During the design input and configuration change impact screening process, an environmental review for possible effects on cultural resources would be triggered. The review would determine whether an activity is within a culturally protected area and, if so, whether ground disturbance or the introduction of noise, air, or visual impacts could be avoided. A Cultural -

Resource Review Form is used to guide and document this process. If a practical avoidance alternative is not available, then consultation with the State Historic Preservation Office (SHPO) is required. The Plan details the process for initiating consultation and for arranging any cultural resource surveys and/or mitigation that may be required.

During excavation activities, a work stoppage would be triggered if human remains, bones, artifacts, prehistoric relics, or items/land features of potential historical significance were discovered or if a recorded archaeological site were adversely impacted. Also, if human remains are discovered, the Pennsylvania State Police are to be notified. Consultation with the SHPO also would be initiated.

To verify that recorded cultural resources have not been adversely affected by human activity, LGS guidance for completion of environmental tasks triggers a visual field reconnaissance of LGS archaeological sites and aboveground historical resources approximately every 12 months.

If evidence of adverse effects is found, mitigative measures are to be implemented in consultation with the SHPO.

Enclosure B Page 49 of 69 E2-28: Enclosure 2: Terrestrial Ecoloy, item A Biodiversity Evaluation of Possum Hollow Run (completed under the direction of Exelon's Environmental Stewardship Committee).

Exelon Response The requested document is provided.

Enclosure B Page 50 of 69 E2-29: Enclosure 2: Terrestrial Ecology, item B Blye, R. 1973. Relative Abundance of Bird Species During Migration.

Exelon Response The requested document is provided.

Enclosure B Page 51 of 69 E2-30: Enclosure 2: Terrestrial Ecology, item C Exelon. 1979-1983. Limerick Generating Station Non-radiological Environmental Report.

Exelon Response The NRC staff and representatives of Exelon Generation held a telephone conference on February 23, 2012, to discuss and clarify whether the staff was requesting only the excerpts that were provided at the Limerick License Renewal Environmental Audit from the referenced document, or the entire document. The staff clarified that only the excerpts provided at the Audit are requested.

The following excerpts, which were provided at the Limerick License Renewal Environmental Audit, from the referenced document are being provided:

• Cover Page

• Table of Contents

• Section 7.0, Asiatic Clam

• Section 8.0, Cooling Tower Bird Mortality

• Section 9.0, Literature Cited

Enclosure B Page 52 of 69 E2-31: Enclosure 2: Terrestrial Ecology, item D Exelon. 1984. Limerick Generating Station Non-radiological Environmental Report.

Exelon Response The NRC staff and representatives of Exelon Generation held a telephone conference on February 23, 2012, to discuss and clarify whether the staff was requesting only the excerpts that were provided at the Limerick License Renewal Environmental Audit from the referenced document, or the entire document. The staff clarified that only the excerpts provided at the Audit are requested.

The following excerpts, which were provided at the Limerick License Renewal Environmental Audit, from the referenced document are being provided:

" Cover Page

• Table of Contents

• Section 7.0, Asiatic Clam

• Section 8.0, Cooling Tower Bird Mortality

• Section 9.0, Literature Cited

Enclosure B Page 53 of 69 E2-32: Enclosure 2: Terrestrial Ecology, item E Exelon. 1985. Limerick Generating Station Non-radiological Environmental Report.

Exelon Response The NRC staff and representatives of Exelon Generation held a telephone conference on February 23, 2012, to discuss and clarify whether the staff was requesting only the excerpts that were provided at the Limerick License Renewal Environmental Audit from the referenced document, or the entire document. The staff clarified that only the excerpts provided at the Audit are requested.

The following excerpts, which were provided at the Limerick License Renewal Environmental Audit, from the referenced document are being provided:

" Cover Page

" Table of Contents

" Section 7.0, Asiatic Clam

" Section 8.0, Cooling Tower Bird Mortality

" Section 9.0, Literature Cited

Enclosure B Page 54 of 69 E2-33: Enclosure 2: Terrestrial Ecology, item F Exelon. 1986. Limerick Generating Station Non-radiological Environmental Report.

Exelon Response The NRC staff and representatives of Exelon Generation held a telephone conference on February 23, 2012, to discuss and clarify whether the staff was requesting only the excerpts that were provided at the Limerick License Renewal Environmental Audit from the referenced document, or the entire document. The staff clarified that only the excerpts provided at the Audit are requested.

The following excerpts, which were provided at the Limerick License Renewal Environmental Audit, from the referenced document are being provided:

• Cover Page

" Table of Contents

" Section 7.0, Asiatic Clam

" Section 8.0, Cooling Tower Bird Mortality

• Section 9.0, Literature Cited

Enclosure B Page 55 of 69 E2-34: Enclosure 2: Terrestrial Ecology, item G Exelon Generation. 2010. Limerick Generating Station Wildlife Management Plan. LGS-R-086 Exelon Response The requested document is provided.

Enclosure B Page 56 of 69 E2-35: Enclosure 2: Terrestrial Ecology, item H Wildlife Habitat Council (WHC). 2006. Site Assessment and Wildlife Management Opportunities. 100 pp. LGS-R-278.

Exelon Response The requested document is provided.

Enclosure B Page 57 of 69 E2-36: Enclosure 2: Terrestrial Ecology, item H Wildlife Habitat Council (WHC). 2006. Site Assessment and Wildlife Management Opportunities. 100 pp. LGS-R-278.

Exelon Response The requested document is provided.

Enclosure B Page 58 of 69 E2-36: Enclosure 2: Terrestrial Ecoloy, item L.a In relation to reference WHC (2006), please provide the following for the indicated Wildlife at Work Projects:

Bird and bat project summary sheets, including location maps, data sheets, and notes.

Exelon Response The requested document is provided.

Enclosure B Page 59 of 69 E2-37: Enclosure 2: Terrestrial Ecology, item I.b.

In relation to reference WHC (2006), please provide the following for the indicated Wildlife at Work Projects:

Frog project summary sheet.

Exelon Response The requested document is provided.

Enclosure B Page 60 of 69 E2-38: Enclosure 2: Terrestrial Ecology, item I.c.

In relation to reference WHC (2006), please provide the following for the indicated Wildlife at Work Projects:

Documented Environmental Evaluation Walkdown/Assessment (for frog fence replacement)

(Report AR 01183399)

Exelon Response The requested document is provided.

Enclosure B Page 61 of 69 E2-39, TE-1: Enclosure 2: Terrestrial Ecology, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-1 is provided.

Enclosure B Page 62 of 69 E2-39, TE-2: Enclosure 2: Terrestrial Ecology. item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-2 is provided.

Please note that the document listed as an attachment to site audit information needs TE-2 is not provided here, but is provided within this package in response to another information request item, as follows:

1, Environmental Working Committee - Biodiversity Evaluation of Possom Hollow is provided in response to Enclosure 2, Terrestrial Ecology, Item A (Index Tab # E2-28).

Enclosure B Page 63 of 69 E2-39, TE-3: Enclosure 2: Terrestrial Ecoloqy, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-3 is provided.

Please note that the documents listed as attachments to site audit information needs TE-3 are not provided here, but are provided within this package in other responses to information requests, as follows:

1. Relative Abundance of Bird Species During Migration, Robert W. Blve, 1973 is provided in response to Enclosure 2, Terrestrial Ecology, Item B (Index Tab # E2-29).

2. Non-Radiological Environmental Monitoring for Limerick Generating Station, 1979 -

1983, Sections 7.0 and 8.0 is provided in response to Enclosure 2, Terrestrial Ecology, Item C (Index Tab # Index E2-30).

3. Non-Radiological Environmental Monitoring for Limerick Generating Station, 1984, Sections 7.0 and 8.0 is provided in response to Enclosure 2, Terrestrial Ecology, Item D (Index Tab # Index E2-31).

4. Non-Radiological Environmental Monitoring for Limerick Generating Station, 1985, Sections 7.0 and 8.0 is provided in response to Enclosure 2, Terrestrial Ecology, Item E (Index Tab # Index E2-32).

5. Non-Radiological Environmental Monitoring for Limerick Generating Station, 1986, Sections 7.0 and 8.0 is provided in response to Enclosure 2, Terrestrial Ecology, Item F (Index Tab # Index E2-33)

Enclosure B Page 64 of 69 E2-39, TE-4: Enclosure 2: Terrestrial Ecology, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-4 is provided.

Please note that the documents listed as attachments to site audit information needs TE-4 are not provided here, but are provided within this package in response to other information request items, as follows:

1. WHC: Wildlife at Work Project Summary Sheet: Bird and Bat Proiect Summary Sheet is provided in response to Enclosure 2, Terrestrial Ecology, Item I.a (Index E2-36).

2. Bird and Bat Box Location Map with Notes is provided in response to Enclosure 2, Terrestrial Ecology, Item I.a (Index E2-36).

3. WHC: Wildlife at Work Proiect Summary Sheet: Frog Proiect Summary Sheet is provided in response to Enclosure 2, Terrestrial Ecology, Item I.b (Index E2-37).

4. AR 01183399 Report, "Documented Environmental Evaluation Walkdown/Assessment" is provided in response to Enclosure 2, Terrestrial Ecology, Item I.c (Index E2-38).

5. Frog Fence Location Map is provided in response to Enclosure 2, Terrestrial Ecology, Item L.b (Index E2-37).

Enclosure B Page 65 of 69 E2-39, TE-5: Enclosure 2: Terrestrial Ecology, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-5 is provided.

Enclosure B Page 66 of 69 E2-39, TE-6: Enclosure 2: Terrestrial Ecology, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-6 is provided.

Please note that the document discussed in site audit information needs TE-6 is not provided here, but is provided within this package in response to another information request item, as follows:

0 Exelon Generation. 2010c. Limerick Generating Station Wildlife Management Plan is provided in response to Enclosure 2, Terrestrial Ecology, Item G (Index Tab # E2-34).

Enclosure B Page 67 of 69 E2-39, TE-7: Enclosure 2: Terrestrial Ecology, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-7 is provided.

Please note that the documents discussed in site audit information needs TE-7 are not provided here, but are provided within this package in response to other information request items, as follows:

• WHC, 2006. WHC (Wildlife Habitat Council). 2006. Site Assessment and Wildlife Management Opportunities prepared for Exelon Corporation's Limerick Generating Station.

100 pp. Illustrated. August is provided in response to Enclosure 2, Terrestrial Ecology, Item H (Index Tab # E2-35).

" Exelon Generation, 2010c. Exelon Generation. 2010c. Limerick Generating Station Wildlife Management Plan is provided in response to Enclosure 2, Terrestrial Ecology, Item G (Index Tab # E2-34).

Enclosure B Page 68 of 69 E2-39, TE-8: Enclosure 2: Terrestrial Ecoloqy, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-8 is provided.

Enclosure B Page 69 of 69 E2-39, TE-9: Enclosure 2: Terrestrial Ecology, item J Submit for docketing the text responses to site audit information needs TE-1, TE-2, TE-3, TE-4, TE-5, TE-6, TE-7, TE-8, and TE-9. These information needs can be found in NRC's Environmental Audit Needs List dated November 4, 2011 (ML11286A330).

Exelon Response The text response to site audit information needs TE-9 is provided.