ML111300156

Email, Request for Additional Information, Nrr/Dss/Scvb Review, Amendment Request for Extended Power Uprate to Increase the Maximum Reactor Core Power Operating Limit from 3898 to 4408 Mwt

ML111300156
Person / Time
Site:	Grand Gulf
Issue date:	05/10/2011
From:	Wang A Plant Licensing Branch IV
To:	Burford J, Millar D Entergy Operations
Wang, A B, NRR/DORL/LPLIV, 415-1445
References
TAC ME4679
Download: ML111300156 (2)

Text

From: Wang, Alan Sent: Tuesday, May 10, 2011 9:37 AM To: 'MILLAR, DANA'; 'Jerry Burford' Cc: Burkhardt, Janet; Lent, Susan

Subject:

Grand Gulf Extended Power Uprate Containment and Ventilation Branch Request for Information (ME4679)

Dana and Jerry, By letter dated September 8, 2010 (Agencywide Documents Access and Management System, Accession No. ML102660403), Entergy Operations, Inc. (Entergy, the licensee), submitted a request to amend the Facility Operating License No. NPF-29 for Grand Gulf Nuclear Station, Unit 1 (GGNS). The licensee proposed a license amendment request (LAR) for an extended power uprate (EPU) to increase the maximum reactor core power operating limit from 3898 megawatts thermal (MWt) to 4408 MWt. The U.S. Nuclear Regulatory Commission (NRC) staff has determined that the following additional information is needed for the NRC staff to complete our review of this amendment . This request for additional information (RAI) was discussed with Mr. Jerry Burford of your staff on April 9, 2011, and it was agreed that a response would be provided within 30 days of receipt of this E-mail. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1445 or via e-mail at Alan.Wang@nrc.gov.

The following are second round RAIs related to the Containment and Ventilation Branch review:

(1) With regards to Entergy letter dated March 31, 2011, Attachment 1, response to RAI No. 1(d), describe the Fire Safe Shutdown (FSSD) analyses for which the initial conditions are given in two columns of the table. In the description include the computer code used, the sequence of events, time of operator actions, and the results. How are these analysis related to the results described in Table 2.5-1, Appendix R Fire Event Evaluation Results, of Power Uprate Safety Analysis Report (PUSAR).

(2) With regards to Entergy letter dated September 8, 2010, Attachment 5B, Section 2.6.1.1, and Table 2.6-1:

(a) Describe the limiting ASDC analysis for which the results are documented in Table 2.6-1.

(b) Provide a comparison of the EPU sequence of events with the current licensing basis sequence of events documented in UFSAR Table 15.2-13 and justify differences.

(c) Provide a comparison of the EPU input parameters for the evaluation of ASDC with the current licensing basis input parameters documented in UFSAR Table 15.2-14 and justify differences.

(3) With regards to PUSAR Figure 2.6-4, discuss the reasons for the three pressure peaks within the first 5 seconds of the main steam line break (MSLB) LOCA analyses pressure response.

(4) With regards to letter dated March 31, 2011, response to RAI No. 1(b), provide the reasons for differences in the model for the MSLB area in the EPU analysis from the

current licensing basis break area model given in UFSAR Figure 6.2-9. Explain the methodology used for calculating these flow areas as a function of time.

(5) With regards to letter dated March 31, 2011, response to RAI 8, for the short term analysis, provide the reasons for using initial drywell pressure of 1.5 psig instead of using the scram setpoint drywell pressure of 2.5 psig or the maximum drywell pressure of 3.5 psig. What value of relative humidity was used in the analysis. In the case where higher than the minimum value of 20-percent was used, provide the justification.

Alan Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation