ML14170B100

Request for Additional Information

ML14170B100
Person / Time
Site:	Hatch
Issue date:	06/23/2014
From:	Martin R Plant Licensing Branch II
To:	Pierce C Southern Nuclear Operating Co
Martin R
References
TAC MF3722, TAC MF3723
Download: ML14170B100 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 23, 2014 Mr. C. R. Pierce Regulatory Affairs Director Southern Nuclear Operating Company, Inc.

Post Office Box 1295, Bin - 038 Birmingham, AL 35201-1295

SUBJECT:

HATCH NUCLEAR PLANT, UNITS 1 AND 2- REQUEST FOR ADDITIONAL INFORMATION (TAC NOS. MF3722 AND MF3723)

Dear Mr. Pierce:

By letter dated March 24, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14084A201 ), Southern Nuclear Operating Company (SNC), a licensee of Edwin I. Hatch Nuclear Plant, Units 1 and 2 (HNP), submitted a license amendment request pursuant to the requirements of Title 10 of the Code of Federal Regulations Parts 50 and

73. SNC requests that the U.S. Nuclear Regulatory Commission (NRC) review and approve a revision to the HNP Technical Specification (TS) Section 2.1.1 to reflect a lower reactor steam dome pressure for Reactor Core Safety Limits 2.1.1.1 and 2.1.1.2. SNC states that the revision is needed to address the potential to exceed the low pressure TS safety limit.

The NRC staff finds that additional information is needed as set forth in the Enclosure. Please provide the additional information within 30 days of the date of this letter.

Sincerely,

~~-*

Robert E. Martin, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-321 and 50-366

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION (RAI)

BY THE OFFICE OF NUCLEAR REACTOR REGULATION SOUTHERN NUCLEAR OPERATING COMPANY. INC ..

EDWIN I. HATCH NUCLEAR PLANT. UNITS 1 AND 2 By letter dated March 24, 2014, Southern Nuclear Operating Company, Inc. (SNC), a licensee of the Edwin I. Hatch Nuclear Plant (HNP) submitted a license amendment request (LAR) for review and approval of a revision to the HNP Technical Specification (TS) Section 2.1.1 to reflect a lower reactor steam dome pressure for Reactor Core Safety Limits 2.1.1.1 and 2.1.1.2. SNC states that the revision is needed to address the potential to exceed the low pressure TS safety limit.

The following additional information is needed to enable continuation of the review.

RAI # 1 Since the proposed approach by SNC is a plant-specific resolution of the Title 10 of the Code of Federal Regulations (1 0 CFR) Part 21 issue discussed in the LAR, please provide the following additional information: *

1. Discuss how SNC plans to address the 10 CFR Part 21 issue when the HNP core may be a mixed core design consisting of more than one fuel design whose Critical Power Ratio (CPR) correlations have different lower-bound pressures.

2. When the HNP core transitions from the current fuel design to fuel design whose lower bound pressure for the CPR correlation is higher (or lower) than that of the current CPR correlation, discuss how SNC plans to address the change affecting the reactor steam dome pressure safety limits specified in the TS. SNC's response should address whether SNC will submit such changes in a further LAR for the NRC staff review and approval. '

RAI#2 In page E1-8 of the LAR, it is stated:

Evaluation of the 10 CFR Part 21 condition by General Electric [GE] determined that since the Minimum Critical Power Ratio improves during the PRFO [Pressure Regulator Failure Maximum Demand] transient, there is no decrease in the safety margin and therefore there is not a threat to fuel cladding integrity.

The U.S. Nuclear Regulatory Commission (NRC) staff understands that, although this 10 CFR Part 21 issue may not be an actual safety hazard, by lowering the dome pressure in TS 2.1.1 from the current value of 785 per square inch grade (psig) to the proposed value of 685 psig that may enable avoidance of an unnecessary reactor shutdown that would otherwise be required by the current TS 2.2.2 if dome pressure goes below 785 psig during a transient.

Enclosure

Discuss if there are any other operational and/or safety benefits of lowering dome pressure from*

the current value of 785 psig to 685 psig.

RAI#3 In page E1-2, Note 2 of the submittal [Reference 1], it was stated:

The GE14 fuel type is currently in use at both HNP units, with the exception of four Westinghouse Leaq Use Assemblies (LUAs) currently in the Unit 1 core. These LUAs are modeled as GE14, and are placed in non-limiting locations.

Further, in page E1-4, Note 6, of the submittal, it was stated:

In accordance with 10 CFR 50.59, only fuel which has an NRC-approved critical power

• correlation with a lower-bound pressure less than or equal to the reactor steam dome pressure specified in the safety limit may be loaded into the core.

Please provide the lower:-bound pressure of the CPR correlation for the LUAs. If it is higher than 685 psig, then provide the following additional information:

1. In light of the 10 CFR 50.59 requirement stated above, justify using the LUAs in the core with the reactor steam dome pressure safety limit set at 685 psig.

2. How does SNC assure that placing the LUAs in nonlimiting locations will prevent Onset of Transition Boiling in these assemblies in a transient when dome pressure becomes lower than the lower-bound pressure of their CPR correlation?

June 23, 2014 Mr. C. R. Pierce Regulatory Affairs Director Southern Nuclear Operating Company, Inc.

Post Office Box 1295, Bin - 038 Birmingham, AL 35201-1295

SUBJECT:

HATCH NUCLEAR PLANT, UNITS 1 AND 2- REQUEST FOR ADDITIONAL INFORMATION (TAC NOS. MF3722 AND MF3723)

Dear Mr. Pierce:

By letter dated March 24, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14084A201 ), Southern Nuclear Operating Company (SNC), a licensee of Edwin I. Hatch Nuclear Plant, Units 1 and 2 (HNP), submitted a license amendment request pursuant to the requirements of Title 10 of the Code of Federal Regulations Parts 50 and

73. SNC requests that the U.S. Nuclear Regulatory Commission (NRC) review and approve a revision to the HNP Technical Specification (TS) Section 2.1.1 to reflect a lower reactor steam dome pressure for R'eactor Core Safety Limits 2.1.1.1 and 2.1.1.2. SNC states that the revision is needed to address the potential to exceed the low pressure TS safety limit.

The NRC staff finds that additional information is needed as set forth in the Enclosure.* Please provide the additional information within* 30 days of the date of this letter.

Sincerely,

/RAJ Robert E. Martin, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-321 and 50-366

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC LPL2-1 R/F MRazzaque, NRR RidsAcrsAcnw_MaiiCTR Resource RidsNrrDoriDpr Resource RidsRgn2MaiiCenter Resource RidsNrrLASFigueroa Resource RidsNrrDorllpl2-1 Resource RidsNrrPMHatch Resource ADAMS A ccess1on No.: ML14170B100 *Bsy ema1*1 dae t d OFFICE DORLILPL2-1 /PM DORLILPL2-1 /LA DSS/SRXB/BC DORL!LPL2-1 /BC DORLILPL2-1 /PM NAME RMartin SFigueroa CJackson* RPascarelli RMartin DATE 06/23/14 06/23/14 06/17/14 06/23/14 06/23/14 OFFICIAL RECORD COPY