ML13032A549
| ML13032A549 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 01/31/2013 |
| From: | Jesse M Exelon Generation Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| Shared Package | |
| ML130320657 | List: |
| References | |
| Download: ML13032A549 (6) | |
Text
PROPRIETARY INFORMATION- WITHHOLD UNDER 10 CFR 2.390 10 CFR 50.90 January 31 , 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278
Subject:
Response to Request for Additional Information License Amendment Request to Revise Technical Specifications to Re-establish Residual Heat Removal System Drywell Spray Function Requirements
References:
- 1) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.
Nuclear Regulatory Commission - License Amendment Request - Revise Technical Specifications to Re-establish Residual Heat Removal System Drywell Spray Function Requirements, dated August 29, 2012 (ML12243A497)
- 2) U.S. Nuclear Regulatory Commission Memorandum from A. B. Ennis to M. K. Khanna- Peach Bottom Atomic Power Station, Units 2 and 3, Draft Request for Additional Information (TAC Nos. ME9445 and ME9446),
dated December 4, 2012 {ML12340A386)
By letter dated August 29, 2012 (Reference 1), Exelon Generation Company, LLC, (Exelon) submitted a License Amendment Request (LAR) for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, requesting changes to the Technical Specifications (TS) to re-establish the requirements for the Residual Heat Removal (AHA) Drywell Spray function in TS. The requirements for the AHA Drywell Spray function are currently contained in Technical Requirements Manual (TAM) Section 3.12, "Residual Heat Removal (RHR)
Drywe/1 Spray." The proposed changes involve establishing a newTS Section 3.6.2.5, "Residual Heat Removal (RHR) Drywe/1 Spray," along with a supporting Bases section, in order to facilitate relocating applicable TAM requirements and re-establishing AHA Drywell Spray function requirements in TS.
In the U.S. Nuclear Regulatory Commission (NRC) memorandum dated December 4, 2012 (Reference 2), the NRC indicated that it had reviewed the supporting information submitted in the Reference 1 letter for the proposed license amendment and needed additional information to support its continued review.
Attachment 2 transmitted herewith contains Proprietary Information.
When the information is separated for the submittal, this document is decontrolled.
U.S. Nuclear Regulatory Commission Response to Request for Additional Information License Amendment Request Re-establish RHR Drywell Spray Function Docket Nos. 50-277 and 50-278 January 31, 2013 Page 2 Accordingly, Attachment 1 provides Exelon's response to the request for information contained in the Reference 2 memorandum. Attachment 2 of this submittal includes pertinent information from a General Electric (GE) report requested by the NRC in support of this response. The information contained in Attachment 2 is considered to be proprietary to GE Hitachi Nuclear Energy. GE Hitachi Nuclear Energy requests that the documentation be withheld from public disclosure in accordance with 1o CFR 2.390. Attachment 3 contains a non-proprietary version of the GE Hitachi Nuclear Energy document. An Affidavit supporting this request is also included in Attachment 3.
Exelon has reviewed the information supporting a finding of No Significant Hazards Consideration and the Environmental Consideration provided to the NRC in the Reference 1 letter. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the additional information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
There are no regulatory commitments contained in this submittal.
If you have any questions or require additional information, please contact Mr. Richard Gropp at (610) 765-5557.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 31st day of January 2013.
Respectfully, .. * *'
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~E\JE~~~irs Exelon Generatron{~ompany, LLC Attachments: 1) Response to Request for Additional Information - License Amendment Request to Re-establish Residual Heat Removal System Drywell Spray Function Requirements
- 2) GE Hitachi Nuclear Energy Report- Excerpted Information (Proprietary Information)
- 3) GE Hitachi Nuclear Energy Report- Excerpted Information (Non-Proprietary Information Version) and Affidavit cc: NRC Region I, Regional Administrator NRC Project Manager, NRR- Peach Bottom NRC Senior Resident Inspector- Peach Bottom S. T. Gray, State of Maryland R. R. Janati, Bureau of Radiation Protection, Commonwealth of Pennsylvania
ATTACHMENT 1 PEACH BOTIOM ATOMIC POWER STATION UNITS 2AND 3 NRC Docket Nos. 50-277 and 50-278 Renewed Facility Operating License Nos.
DPR-44 and DPR-56 Response to Request for Additional Information License Amendment Request to Re-establish Residual Heat Removal System Drywall Spray Function Requirements Response to RAI Re-establish RHR Drywell Spray Function Docket Nos. 50-277 and 50-278 Page 1 of 3 Response to Request for Additional Information License Amendment Request to Revise Technical Specifications to Re-establish Residual Heat Removal System Drywell Spray Function Requirements
Background
By letter dated August 29, 2012 (Reference 1), Exelon Generation Company, LLC, (Exelon) submitted a License Amendment Request (LAR) for the Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, requesting changes to the Technical Specifications (TS) to re-establish the requirements for the Residual Heat Removal (RHR) Drywell Spray function in TS. The requirements for the RHR Drywell Spray function are currently contained in Technical Requirements Manual (TAM) Section 3.12, "Residual Heat Removal (RHR) Drywe/1 Spray." The proposed changes involve establishing a newTS Section 3.6.2.5, "Residual Heat Removal (RHR) Drywe/1 Spray," along with a supporting Bases section, in order to facilitate relocating applicable TAM requirements and re-establishing RHR Drywell Spray function requirements in TS.
In the U.S. Nuclear Regulatory Commission (NRC) memorandum dated December 4, 2012 (Reference 2), the NRC requested additional information in support of its review of the requested amendment. The specific questions are restated below followed by Exelon's response.
NRC Question 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 drywe/1 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
"... drywe/1 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 Drywe/1 Sprays are the primary success path for mitigating the effects of a SSLB in the drywe/1.
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.
Response
In 2001, General Electric (GE) (currently GE Hitachi Nuclear Energy) issued Service Information Letter (SIL) 636 (Reference 3) to inform utilities with GE Boiling Water Reactors (BWRs) of a change in the GE method for calculating the decay heat values using the ANS 5.1-1979 standard (Reference 4). In March 2003, GE provided Revision 0 of GE-NE-0000-0011- 4483, "Project Task Report- Peach Bottom Atomic Power Station Units 2 and 3 SIL 636 Evaluation,"
Response to RAI Re-establish RHR Drywell Spray Function Docket Nos. 50-277 and 50-278 Page 2 of 3 (Reference 5) documenting the results of an assessment for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, relative to the design and licensing analyses potentially impacted by the revised decay heat calculation method described in SIL 636. Since PBAPS did not have a Small Steam Line Break Analysis (SSLB), GE was requested to include an SSLB analysis in the SIL 636 evaluation. Section 9 of this GE report includes the information relative to the SSLB analysis that was performed.
Therefore, as requested, pertinent information from the GE report (i.e., GE-NE-0000-0011-4483, Revision 0) which includes Section 9 documentation is included in Attachment 2 of this submittal.
The documentation provided in Attachment 2 is proprietary to GE Hitachi Nuclear Energy; therefore, GE Hitachi Nuclear Energy requests that the documentation be withheld from public disclosure in accordance with 10 CFR 2.390. GE Hitachi Nuclear Energy has identified this documentation as NEDC-33808P, "Peach Bottom Atomic Power Station Units 2 and 3 SIL 636 Evaluation Small Break LOCA," dated January 2013 (Reference 6). A copy of a non-proprietary version of this report is included in Attachment 3 along with a supporting Affidavit.
The table below provides a summary of the expected peak drywell temperatures during the analyzed DBA-LOCA and SSLB accident conditions.
Accident Condition Temperature DBA- LOCA Peak Drywell Temperature (no credit for Drywell Sprays) 307° F SSLB Peak Drywell Temperature (credit for Drywell Sprays) 337.9° F Maximum Drywell Temperature Limit 340° F As noted above, the maximum drywell temperature expected for the SSLB accident with credit for Drywell Sprays is 337.9° F, which remains below the 340° F limit.
NRC Question 2 As discussed in question 1 above, the licensee determined that RHR Drywe/1 Sprays are the primary success path for mitigating the effects of a SSLB in the drywe/1. Please describe the timeline when the licensee determined that the RHR Drywe/1 Spray is needed to mitigate the impact of a SSLB. If the licensee's determination was not made soon after the results of the GE analysis was available to the licensee, then explain why the licensee's decision to make the proposed change to revise the TSs to include newTS Section 3.6.2.5 (along with a supporting Bases section) was not made at an earlier date.
Response
The vendor analysis was performed in 2003 and assumed the use of Drywell Spray to mitigate the Small Steam Line Break (SSLB) design event. At that time, Drywell Spray was controlled in the PBAPS, Units 2 and 3, Technical Requirements Manuals (TAMs), which are documents that are similar to the PBAPS TSs. The TRM document generally contains similar limiting conditions and compensatory measures as does the TS and therefore, the impact of Drywell Spray being contained in the TRM instead of the TS was not significant. The PBAPS staff recognized on June 5, 2012, that the Drywell Spray function should be transferred from the TAMs to the TSs.
Once recognized, the issue was promptly entered into the Corrective Action Program (CAP)
(reference Issue Report 1375137) for resolution and is available for review by the site NRC Response to RAI Re-establish RHR Drywell Spray Function Docket Nos. 50-277 and 50-278 Page 3 of 3 Resident Inspectors. The causes of the delay in recognizing the need to transfer the Drywall Spray from the TRMs to the TSs were due to inadequate identification of document impacts of the vendor analysis and a non-conservative decision to not include Drywall Spray in the TSs when performing the conversion to Improved Technical Specifications (ITS) in the 1990s.
References
- 1. Letter from M.D. Jesse (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission- License Amendment Request- Revise Technical Specifications toRe-establish Residual Heat Removal System Drywell Spray Function Requirements, dated August 29, 2012 (ML12243A497)
- 2. U.S. Nuclear Regulatory Commission Memorandum from R. B. Ennis to M. K. Khanna-Peach Bottom Atomic Power Station, Units 2 and 3, Draft Request for Additional Information (TAG Nos. ME9445 and ME9446), dated December 4, 2012 (ML12340A386)
- 4. ANS 5.1-1979, Decay Heat Power in Light Water Reactors
- 5. GE-NE-0000-0011- 4483, Revision 0 - Project Task Report- Peach Bottom Atomic Power Station Units 2 and 3 SIL 636 Evaluation, dated March 2003