ML16099A202

Mellla+ License Amendment Issuance - Request for Corrections to Approved License Amendment Safety Evaluation

ML16099A202
Person / Time
Site:	Peach Bottom
Issue date:	04/08/2016
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CAC MF4760, CAC MF4761
Download: ML16099A202 (5)

Text

Exelon Generation,.

10 CFR 50.4 April 8, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Unit 2 and Unit 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278

Subject:

MELLLA+ License Amendment Issuance - Request for Corrections to Approved License Amendment Safety Evaluation

Reference:

NRC letter to Exelon, "Peach Bottom Atomic Power Station, Units 2 and 3 -

Issuance of Amendments RE: Maximum Extended Load Line Limit Analysis Plus (CAC Nos. MF4760 and MF4761)," dated March 21, 2016 (ADAMS Accession No. ML16034A372)

In accordance with 10 CFR 50.90, Exelon Generation Company, LLC (EGC) requested amendments to Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS) Units 2 and 3, respectively. Specifically, the proposed changes requested to revise the Renewed Operating Licenses to allow operation in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) operating domain and the use of the Detect and Suppress - Confirmation Density (DSS-CD) stability solution.

The NRC approved this request and issued Amendment Nos. 305 and 309 to- Renewed Facility Operating License Nos. DPR-44 and DPR-56 for PBAPS, Units 2 and 3, respectively (Reference). The accompanying NRC Safety Evaluation (SE) was reviewed by EGC and found to contain a few minor inaccuracies and typographical errors. to this letter identifies these issues. EGC requests that NRC review and correct the identified areas and re-issue the Amendment Nos. 305 and 309 SE.

Should you have any questions concerning this letter, please contact David B. Neff at (610) 765-5631.

Respectfully,

~~~

James Barstow Director, Licensing & Regulatory Affairs Exelon Generation Company, LLC

U.S. Nuclear Regulatory Commission MELLLA+ SE Correction Request April 8, 2016 Page 2 NRC Final SE Comments from Exelon regarding PBAPS MELLLA+

Amendment Nos. 305 and 309 cc: USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Project Manager, PBAPS R. R. Janati, Commonwealth of Pennsylvania S. T. Gray, State of Maryland

ATTACHMENT 1 NRC Final SE Comments from Exelon Regarding PBAPS MELLLA+ Amendment Nos. 305 and 309 Peach Bottom Atomic Power Station - Unit 2 and Unit 3 NRC Docket Nos. 50-277 and 50-278

Attachment 1 NRC Final SE Comments from Exelon Regarding PBAPS MELLLA+ Amendment Nos. 305 and 309 Peach Bottom Atomic Power Station - Unit 2 and Unit 3 NRC Docket Nos. 50-277 and 50-278 Page 1 of 2 SE SE Section Page Comment Reference Number Number 3.3.9 60 Table 3.3.9-1: PBAPS SAR (NEDC-33720P REV 0), Table 9-1, page 9-16.

Last two column data or headers are reversed. The 83% rated flow and 110% rated flow column data does not align with the column headers.

3.3.9 65 SAR Sections 9.3.1 and 9.3.3 - ATWS and ATWSI, PBAPS SAR (NEDC-33720P REV 0), section ATWS Subsection: First paragraph, second and 9.3.1.2, page 9-12, first paragraph:

third sentences:

near the SRV Replace the word at with near before the SRV.

Add the word peak prior to suppression pool Page 9-13, first bullet:

temperature.

peak suppression pool temperature 3.4.4 82 Technical Evaluation: Transient Response: PBAPS SAR (NEDC-33720P REV 0) page 9-16, Table 9-1, AOO Event Results Summary Note For clarity, the following text is recommended to be 1:

rephrased since the MELLLA+ SAR reports uncorrected CPR/ICPR results for AOO. For the pressurization events, the uncorrected CPR/ICPR values are presented and for the slow Third sentence: As seen in that evaluation, transients (LFWH and RWE), Option B CPR is operation at lower flows in the MELLLA+ presented.

domain has a small impact (~0.03 in uncorrected CPR/ICPR) on transient response, and the limiting initiating conditions are at 83 percent core flow for all AOOs analyzed.

3.4.5.5 87 Technical Evaluation, first paragraph, second PBAPS SAR (NEDC-33720P REV 0), Section sentence: 9.3.1 Anticipated Transients without Scram, page 9-10, top paragraph, last sentence:

The HSBW is confirmed effective on plant- and cycle- As required by M+LTR SER Limitation and specific bases with ODYN and TRACG ATWS Condition 12.23.8, the plant-specific ATWS calculations. analyses account for plant- and fuel-design-specific features including debris filters.

This statement is not accurate. ATWS analysis is There is no mention of cycle-specific analysis in cycle independent. No cycle specific confirmation is Section 9.3.1.

performed with either TRACG or ODYN. The TRACG ATWS calculations are used to determine the initial Section 9.3.1.1 Anticipated Transients without overpressure response and this analysis ends before Scram (Licensing Basis), page 9-10, first the Standby Liquid Control System (SLCS) is initiated. paragraph, Figure 9-4, page 9-26 and Figures 9-5 The ODYN ATWS calculations are used of the long and 9-6, pages 9-27 and 9-28 regarding methods analysis and include operation of the SLCS where used for overpressure and long-term analyses.

HSBW is considered. Suggested wording: The HSBW is confirmed effective on a plant- and fuel- Section 9.3.1.1, page 9-11, second paragraph design-specific basis with ODYN calculations. regarding SLCS boron injection time.

MELLLA+ LTR SE (NEDC-33006P-A REV 3),

ATWS is evaluated under the heading

SUMMARY

OF IMPACT OF MELLLA+ ON FUEL DEPENDENT PLANT RESPONSE, page xiii. There is no mention of cycle-specific evaluation of ATWS in this section.

Attachment 1 NRC Final SE Comments from Exelon Regarding PBAPS MELLLA+ Amendment Nos. 305 and 309 Peach Bottom Atomic Power Station - Unit 2 and Unit 3 NRC Docket Nos. 50-277 and 50-278 Page 2 of 2 SE SE Section Page Comment Reference Number Number 3.5.2 92 Limitation and Condition 12.7: See PBAPS TS 3.3.1.1 ACTION I.

ACTION I.1 - Immediately initiate action to For clarity, the following text is recommended to be implement the Manual Backup Stability Protection rephrased since the BSP Boundary is not applicable (BSP) Regions defined in the COLR.

during the time period of transitioning to ABSP. ACTION I.2 - Within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, implement the Automated BSP Scram Region using the modified From: APRM Simulated Thermal Power-High scram The DSS-CD automated BSP option will be setpoints defined in the COLR.

implemented at PBAPS. If the primary OPRM DSS-CD scram is declared inoperable, manual BSP will be DSS-CD LTR (NEDC 33075P-A REV 8), Section implemented immediately by reducing the operating 7.5.2 page 7-15 states when DSS-CD solution is power line until the automated BSP option can be inoperable, the Automated BSP option requires that activated in the DSS-CD computer. the operator implement the automatic BSP scram option within 12 hrs. During this time, Manual BSP To: regions are implemented as specified in TS 3.3.1.1 The DSS-CD Automated BSP option will be ACTION I. The Manual BSP regions are defined in implemented within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> at PBAPS when the the COLR.

DSS-CD solution is declared inoperable. During this time, Manual BSP will be implemented as specified by PBAPS TS 3.3.1.1 ACTION I.

3.5.2 92 Limitation and Condition 12.8: PBAPS SAR (NEDC-33720P REV 0), Section 3.2.1, pages 3-2 and 3-3: The change to the The statement in the SE The change of vessel PBAPS 54 effective full power years (EFPY) vessel effective full power years is estimated to be (( )) internal diameter (ID) peak fluence as a result of at 54 EFPY is confusing. Recommend revising to: implementing MELLLA+ is ((

The change in vessel peak fluence is (( )) at 54 ))

EFPY.

Appendix B B1 ACRONYM Column , ARI: PBAPS SAR (NEDC-33720P REV 0) Acronyms, page xi. Typographical correction.

ARI is defined as Alternate Rod Insertion, not Alternative Rod Injection.