ML12340A386
| ML12340A386 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/04/2012 |
| From: | Richard Ennis Plant Licensing Branch 1 |
| To: | Meena Khanna Plant Licensing Branch 1 |
| Ennis R NRR/DORL/LPL1-2 301-415-1420 | |
| References | |
| TAC ME9445, TAC ME9446 | |
| Download: ML12340A386 (4) | |
Text
December 4, 2012 MEMORANDUM TO:
Meena K. Khanna, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Richard B. Ennis, Senior Project Manager /RA/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3, DRAFT REQUEST FOR ADDITIONAL INFORMATION (TAC NOS.
ME9445 AND ME9446)
The attached draft request for additional information (RAI) was transmitted on December 4, 2012, to Mr. Thomas Loomis of Exelon Generation Company, LLC (Exelon, the licensee). This information was transmitted to facilitate an upcoming conference call in order to clarify the licensees amendment request for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, dated August 29, 2012. The proposed amendment would add Technical Specification (TS) requirements for the Residual Heat Removal (RHR) Drywell Spray function. This function had previously resided in the TSs for PBAPS, Units 2 and 3, but was relocated to a licensee-controlled document, the Technical Requirements Manual, as part of the conversion to the improved TSs on August 30, 1995. Based on the requirements in Section 50.36 of Title 10 of the Code of Federal Regulations (10 CFR), the licensee has determined that the RHR Drywell Spray function needs to be re-established in the TSs for PBAPS, Units 2 and 3.
The draft RAI was sent to Exelon to ensure that the questions are understandable, the regulatory basis for the questions is clear, and to determine if the information was previously docketed. This memorandum and the attachment do not convey or represent an NRC staff position regarding the licensee's request.
Docket Nos. 50-277 and 50-278
Attachment:
Draft RAI
December 4, 2012 MEMORANDUM TO:
Meena K. Khanna, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Richard B. Ennis, Senior Project Manager /RA/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3, DRAFT REQUEST FOR ADDITIONAL INFORMATION (TAC NOS.
ME9445 AND ME9446)
The attached draft request for additional information (RAI) was transmitted on December ?,
2012, to Mr. Thomas Loomis of Exelon Generation Company, LLC (Exelon, the licensee). This information was transmitted to facilitate an upcoming conference call in order to clarify the licensees amendment request for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, dated August 29, 2012. The proposed amendment would add Technical Specification (TS) requirements for the Residual Heat Removal (RHR) Drywell Spray function. This function had previously resided in the TSs for PBAPS, Units 2 and 3, but was relocated to a licensee-controlled document, the Technical Requirements Manual, as part of the conversion to the improved TSs on August 30, 1995. Based on the requirements in Section 50.36 of Title 10 of the Code of Federal Regulations (10 CFR), the licensee has determined that the RHR Drywell Spray function needs to be re-established in the TSs for PBAPS, Units 2 and 3.
The draft RAI was sent to Exelon to ensure that the questions are understandable, the regulatory basis for the questions is clear, and to determine if the information was previously docketed. This memorandum and the attachment do not convey or represent an NRC staff position regarding the licensee's request.
Docket Nos. 50-277 and 50-278
Attachment:
Draft RAI DISTRIBUTION PUBLIC MRazzaque, SRXB LPL1-2 R/F MHamm, STSB RidsNrrDorlLpl1-2 Resource RidsNrrDorlDpr Resource RidsNrrPMPeachBottom Resource ADAMS ACCESSION NO.: ML12340A386 OFFICE LPL1-2/PM NAME REnnis DATE 12/4/2012 OFFICIAL RECORD COPY
Attachment DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED LICENSE AMENDMENT REVISE TECHNICAL SPECIFICATIONS TO ADD REQUIREMENTS FOR THE RESIDUAL HEAT REMOVAL DRYWELL SPRAY FUNCTION PEACH BOTTOM ATOMIC POWER STATION - UNITS 2 AND 3 DOCKET NOS. 50-277 AND 50-278 By letter to the Nuclear Regulatory Commission (NRC) dated August 29, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12243A497), Exelon Generation Company, LLC (Exelon, the licensee), submitted a license amendment request for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. The proposed amendment would add Technical Specification (TS) requirements for the Residual Heat Removal (RHR) Drywell Spray function. This function had previously resided in the TSs for PBAPS, Units 2 and 3, but was relocated to a licensee-controlled document, the Technical Requirements Manual, as part of the conversion to the improved TSs (ITS) on August 30, 1995. Based on the requirements in Section 50.36 of Title 10 of the Code of Federal Regulations (10 CFR), the licensee has determined that the RHR Drywell Spray function needs to be re-established in the TSs for PBAPS, Units 2 and 3.
The NRC staff has reviewed the information the licensee provided that supports the proposed amendment and would like to discuss the following issues to clarify the submittal.
- 1.
The third paragraph on page 4 of Attachment 1 of the application dated August 29, 2012, states:
At the time of the ITS conversion, it had not been recognized that a Small Steam Line Break (SSLB) accident may result in higher peak drywell temperatures than that produced by Design Basis Accident (DBA) Loss of Coolant Accident (LOCA) (i.e., Recirculation Suction Line Break (RSLB)).
Subsequently, however, an analysis performed in response to General Electric (GE) Service Information Letter (SIL) 636 concluded that an SSLB will result in higher containment temperatures than that of DBA LOCA. Based on this determination, the earlier justification that "drywell spray is not credited in any DBA (i.e., it is not needed to function to mitigate the consequence of any design basis accidents)," is not correct. Although evaluated as not being required to mitigate a DBA, RHR Drywell Sprays are the primary success path for mitigating the effects of a SSLB in the drywell.
Please provide the report that documents the detailed results of the GE analysis, and the date the analysis was performed in response to GE SIL 636.
- 2.
As discussed in question 1 above, the licensee determined that RHR Drywell Sprays are the primary success path for mitigating the effects of a SSLB in the drywell. Please describe the timeline when the licensee determined that the RHR Drywell Spray is needed to mitigate the impact of a SSLB. If the licensees determination was not made soon after the results of the GE analysis was available to the licensee, then explain why the licensees decision to make the proposed change to revise the TSs to include new TS Section 3.6.2.5 (along with a supporting Bases section) was not made at an earlier date.