ML12095A398

Request for Additional Information for the Review of the Limerick Generating Station, Units 1 and 2, License Renewal Application (TAC Nos ME6555 and ME6556)TLAA Follow-up RAIs

ML12095A398
Person / Time
Site:	Limerick
Issue date:	04/17/2012
From:	Robert Kuntz License Renewal Projects Branch 1
To:	Gallagher M Exelon Generation Co
Kuntz R
References
TAC ME6555, TAC ME6556
Download: ML12095A398 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 17, 2012 Mr. Michael P. Gallagher Vice President, liCense Renewal Projects Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348

SUBJECT:

REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE LIMERICK GENERATING STATION, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (TAC NOS. ME6555 AND ME6556)

Dear Mr. Gallagher:

By letter dated June 22, 2011, Exelon Generation Company, LLC submitted an application pursuant to Title 10 of the Code of Federal Regulations, Part 54, to renew the operating licenses for Limerick Generating Station, Units 1 and 2, for review by the U.S. Nuclear Regulatory Commission (NRC or the staff). The staff is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review.

These requests for additional information (RAls) were discussed with Christopher Wilson, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me by telephone at 301-415-3733 or bye-mail at Robert. Kuntz@nrc.gov.

Sincerely, ntz, Senior Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

Requests for Additional Information cc w/encl: Listserv

LIMERICK GENERATING STATION LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION RAI4.1-1.1

Background

Updated Final Safety Analysis Report (UFSAR) Section 3.9.1.1.8 was referenced in the response to RAI 4.1-1. UFSAR Section 3.9.1.1.8 contains a listing of transients in the main steam isolation valve (MSIV) fatigue analysis. One of these transients included in this section is "Preop @ 100 F/hr" with a limit of 150 cycles.

The staff noted that the "Preop @ 100 F/hr" transient was not included in LRA Tables 4.3.1-1 and 4.3.1-2; therefore, it is not clear to the staff whether this transient is monitored, needs to be monitored or will be monitored during the period of extended operation.

Request Clarify if this transient, "Preop @ 100 F/hr," is associated with a transient that is already monitored by the Fatigue Monitoring Program. If not, justify why this transient does not need to be monitored by the Fatigue Monitoring Program.

RAI4.3-S.1

Background

The response to RAI 4.3-6, in letter dated February 29, 2012, discusses the environmental assisted fatigue evaluation for American Society of Mechanical Engineers (ASME) Code Class 1 valves. The applicant's results of the analyzed ASME Code Class 1 valves from this evaluation were also provided as part of the response.

LRA Sections 4.3.3 and A.4.3.3 were not updated to include the results and description of the evaluation of environmentally assisted fatigue for ASME Code Class 1 valves. Therefore, it is not clear whether these environmental assisted fatigue evaluations are included as part of the 10 CFR 54.21 (c)(1 )(iii) disposition and are part of the Fatigue Monitoring Program.

Request Confirm that the environmental assisted fatigue analyses for ASME Code Class I valves are managed by the Fatigue Monitoring program and are included in the disposition in accordance with 10 CFR 54.21 (c)(1)(iii) in LRA Section 4.3.3 and A.4.3.3.

- 2 If not, justify that LRA Sections 4.3.3 and A.4.3.3 do not need to be updated to include information associated with the environmentally assisted fatigue evaluations for ASME Code.

Class 1 valves and that they are also managed by the Fatigue Monitoring Program for environmentally assisted fatigue.

RAI4.3-S.2

Background

Page 15 of 30 in response to RAI4.3-6, in letter dated February 29,2012, it states "[t]he RHR shutdown cooling system valves are exposed to transients associated with shutdown cooling operations that are not experienced by the RHR LPCI and core spray injection valves. The RHR LPCI and core spray injection valves are only exposed to transients that are also experienced by the RHR shutdown cooling return valves."

It is not clear what transients are experienced by the RHR SOC valves and by the RHR LPCI and core spray injection valves.

Request Confirm that statements 1 and 2 are true:

1) RHR SOC valves experience: (transients associated with shutdown cooling operations)

+ (transients X, Y, Z ... )

2) RHR LPCI and core spray injection valves experience: (transients X, Y, Z ... )

AND RHR LPCI and core spray injection valves 00 NOT experience: (transients associated with shutdown cooling operations)

If both statements are not true, clarify what transients are experienced by the RHR SOC valves and by the RHR LPCI and core spray injection valves.

RAI4.3-9.1 Background and issue The response to RAI 4.3-9 (Part 1), provided by letter dated February 29, 2012, stated that the revised environmental fatigue analysis evaluates the inside surface location at the clad/base metal interface directly below the limiting outside surface location. This location was selected to represent the wetted internal surface of the forging but takes no credit for the presence of the cladding. Since this location was not originally analyzed for metal fatigue, no ASME Code cumulative usage factor (CUF) value is reported. However, the response revised Table 4.3.3-1 for the ASME Code CUF value for Core Spray Nozzle (Forging) from 0.097 to 0.0016. The response does not explain what the value of 0.0016 represents since the response indicated that no ASME Code CUF value is reported for this location.

- 3 The staff also noted that for the core spray piping in Tables 4.3.3-2, the difference in Fen values between Limerick Generation Station (LGS), Units 1 and 2 is substantial. The staff recognized that different nodes are reported. However, the response did not explain the difference in Fen.

Request

1. Explain the ASME Code CUF value of 0.0016 for Core Spray Nozzle (Forging) in Table 4.3.3-1.

2. Explain why the Fen values for the core spray piping are different between LGS, Units 1 and 2.

RAI4.3-10.1 Background and issue The response to RAI 4.3-10, provided by letter dated February 29, 2012, provided the CUF values for a list of components that have been analyzed for fatigue. The response indicated that the steam dryer, steam dryer support brackets, and control rod guide tube are "exempt."

The response did not explain why these three components are exempted in the fatigue analysis.

Request Clarify why these three components are exempted. As part of the clarification, if applicable, identify the provisions in the ASME Code Section III that allowed the exemption of the required fatigue analysis for these components.

Letter to M. Gallagher from R. Kuntz dated April 17, 2012

SUBJECT:

REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE LIMERICK GENERATING STATION, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (TAC NOS. ME6555 AND ME6556)

DISTRIBUTION:

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'.. ML12095a398 PM:RPB1 :DLR BC:RPB1 :DLR PM: RPB1 :DLR OFFICE LA:RPB1:DLR NAME YEdmonds RKuntz DMorey RKuntz DATE 4/12/12 4/12/12 4/12/12 41 17 112