ML19022A307

Draft Safety Evaluation for Proposed Amendment 46 to NEDE-24011-P-A-26, General Electric Standard Application for Reactor Fuel (Gestar II)

ML19022A307
Person / Time
Site:	99901376
Issue date:	02/14/2019
From:	Dennis Morey NRC/NRR/DLP/PLPB
To:	Michelle Catts GE-Hitachi Nuclear Energy Americas
Golla J, NRR/DLP/PLPB, 415-1002
References
EPID L-2018-TOP-0007
Download: ML19022A307 (6)

Text

February 14, 2019 Ms. Michelle P. Catts Senior Vice President, Regulatory Affairs GE-Hitachi Nuclear Energy Americas, LLC P.O. Box 780, M/C A-10 Wilmington, NC 28401-0780

SUBJECT:

DRAFT SAFETY EVALUATION FOR PROPOSED AMENDMENT 46 TO NEDE-24011-P-A-26, GENERAL ELECTRIC STANDARD APPLICATION FOR REACTOR FUEL (GESTAR II) TO PROVIDE CLARITY AND FORMALITY TO THE STANDBY LIQUID CONTROL SYSTEM (SLCS) SHUTDOWN MARGIN ANALYSIS (EPID L-2018-TOP-0007)

Dear Ms. Catts:

By letter dated February 9, 2018 (Agencywide Documents Access and Management System Accession No. ML18040A183), Global Nuclear Fuel - Americas, LLC (GNF) submitted Proposed Amendment 46 to NEDE-24011-P-A-26, General Electric Standard Application for Reactor Fuel (GESTAR II) to Provide Clarity and Formality to the Standby Liquid Control System (SLCS) Shutdown Margin Analysis, to the U.S. Nuclear Regulatory Commission (NRC) staff for review. Enclosed for GEH review and comment is a copy of the NRC staffs draft safety evaluation (SE) for the proposed supplement.

Twenty working days are provided for you to comment on any factual errors or clarity concerns contained in the draft SE. The final SE will be issued after making any necessary changes.

The NRC staffs disposition of your comments on the draft SE will be discussed in the final SE.

To facilitate the NRC staffs review of your comments, please provide a marked-up copy of the draft SE showing proposed changes and provide a summary table of the proposed changes.

If you have any questions, please contact Joseph Golla at 301-415-1002.

Sincerely,

/RA/

Dennis C. Morey, Chief Licensing Processes Branch Division of Licensing Projects Office of Nuclear Reactor Regulation Docket No. 99901376

Enclosure:

Draft SE

cc w/ encl.:

Mr. Kent E. Halac Senior Project Manager, Regulatory Affairs GE-Hitachi Nuclear Energy Americas, LLC P.O. Box 780, M/C A-70 Wilmington, NC 28401-0780 Kent.Halac@ge.com Dr. Brian R. Moore General Manager, Core & Fuel Engineering Global Nuclear Fuel-Americas, LLC P.O. Box 780, M/C A-75 Wilmington, NC 28401-0780 Brian.Moore@ge.com Ms. Lisa K. Schichlein Senior Project Manager, Regulatory Affairs GE-Hitachi Nuclear Energy Americas, LLC P.O. Box 780, M/C A-70 Wilmington, NC 28401-0780 Lisa.Schichlein@ge.com

ML19022A307 *concurrence via e-mail NRR-043 OFFICE NRR/DLPPLPB/PM NRR/DLPPLPB/LA* NRC/DSS/SNPB/BC NRR/DLPPLPB/BC NAME JGolla DHarrison RLukes DMorey DATE 2/7/2019 2/5/2019 2/13/2019 2/14/2019 1 OFFICE OF NUCLEAR REACTOR REGULATION 2 SAFETY EVALUATION FOR AMENDMENT 46 TO GLOBAL NUCLEAR FUEL - AMERICAS 3 TOPICAL REPORT NEDE-24011-P-A-26, 4 GENERAL ELECTRIC STANDARD APPLICATION FOR REACTOR FUEL 5 (EPID: L-2018-TOP-0007) 6 7

1.0 INTRODUCTION AND BACKGROUND

8 9 By letter dated February 9, 2018, Global Nuclear Fuel - Americas, LLC (GNF) submitted 10 Amendment 46 (Agencywide Documents and Access Management System No. ML18040A183) 11 (Ref. 1) to Topical Report (TR) NEDE-24011-P-A-26, General Electric Standard Application for 12 Reactor Fuel (GESTAR II) to the U.S. Nuclear Regulatory Commission staff for review (Ref. 2).

13 14 In Amendment 46, GNF requests to amend GESTAR II to provide clarity and formality to the 15 Standby Liquid Control System (SLCS) shutdown margin analysis without changing the 16 methodology for SLCS shutdown margin calculation. Appendix A of GESTAR II, Standard 17 Supplemental Reload Licensing Report and Fuel Bundle Information Report Template, 18 Section 5, Standby Liquid Control System Capability is proposed to be revised to use a variable 19 designation for the plant specific analysis temperatures instead of specific values.

20 21 The draft safety evaluation (SE) for the Amendment 46 follows.

22 23

2.0 REGULATORY EVALUATION

24 25 Not Applicable in this case 26 27

3.0 TECHNICAL EVALUATION

28 29 3.1 Introduction 30 31 Amendment 46 to GESTAR II consists of modification and clarification of Section 3.2.4.3 of 32 NEDO-24011-P-A-26, SLCS shutdown margin analysis. The SLCS provides an alternative 33 means of reactor shutdown by injecting soluble boron into the reactor core moderator. SLCS is 34 designed to provide the capability of bringing the reactor, at any time in a cycle, to a subcritical 35 condition with the reactor in the most reactive xenon-free state with all of the control rods in the 36 full-out condition. The requirements of the SLCS are dependent primarily on the reactor power 37 level and on the reactivity effects of voids and temperature between full power and cold, 38 xenon-free condition. Amendment 46 provides detailed clarification and formality to the SLCS 39 shutdown margin analysis.

40 41 42 Enclosure 43

1 3.2 Amendment 46 to GESTAR II 2

3 The SLCS shutdown margin, which is the difference between the cold critical eigenvalue and 4 the eigenvalue predicted for the borated conditions using the boiling water reactor simulator 5 code, is calculated based on the limiting reactivity carryover from the expected previous cycle 6 shutdown.

7 8 The SLCS analysis is performed for the specific cycle and fuel type using borated fuel libraries 9 at a temperature corresponding to the most reactive condition for the cycle. The most reactive 10 condition is when the shutdown cooling mode of the residual heat removal (RHR) system is 11 initiated, which results in a substantial dilution of the boron concentration (BC) due to the 12 inclusion of the RHR system volume. The RHR startup occurs at a state when the SLCS 13 shutdown margin is at a minimum value since the borated water has a positive moderator 14 temperature coefficient. The evaluated BC is the technical specifications BC which is adjusted 15 for changes in water density between its reference temperature and the analysis temperature.

16 17 The minimum SLCS shutdown margin requirement includes biases and uncertainties associated 18 with the calculation that includes: (1) bias and uncertainty associated with the calculation of a 19 cold, un-borated core determined form benchmarks of the BWR core simulator code against 20 cold critical plant startup data, and (2) bias and uncertainty associated with the calculation of the 21 worth of boron as determined from benchmarks of the lattice physics code against higher order 22 computational methods benchmarked against critical experiments.

23 24 For temperatures less than the most reactive condition, in order to account for the temperature 25 effect, an additional reactivity bias is included. The uncertainties are one-sided 95/95 tolerance 26 level multiplies combined with biases to establish the SLCS shutdown margin requirement 27 needed to assure subcriticality.

28 29 The SLCS shutdown margin requirement depends on the fuel type. The most conservative 30 requirement is applied when a core consists of multiple fuel design types.

31 32 The shutdown capability of the SLCS is given in the final safety analysis report or in the 33 supplemental reload licensing report (SRLR). The SRLR template as modified is revised to use 34 a variable designation for plant specific analysis temperatures instead of specific values.

35 36

4.0 CONCLUSION

37 38 The staff reviewed the documents related to the GESTAR II Amendment 46 regarding the SLCS 39 shutdown margin analysis and found Amendment 46 acceptable. The request for 40 Amendment 46 to GESTAR II is hereby approved for use by the licensees.

41 42 43

1

5.0 REFERENCES

2 3 1. Letter, M180032 from Brian Moore (GNF- A) to US NRC, Proposed Amendment 46 to 4 NEDE-24011-P-A-24, General Electric Standard Application for Reactor Fuel 5 (GESTAR II) to Provide Clarity and Formality to the Standby Liquid Control System 6 (SLCS) Shutdown Margin Analysis, Global Nuclear Fuel, February 9, 2018.

7 8 2. NEDE-24011-P-A-26, General Electric Standard Application for Reactor Fuel 9 (GESTAR II), Global Nuclear Fuel, January 2018.

10 11 Principal Contributor: Mathew M. Panicker 12 13 Date:

14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37