ML20273A310
| ML20273A310 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 10/02/2020 |
| From: | Xcel Energy |
| To: | Office of Nuclear Material Safety and Safeguards |
| Kuntz R | |
| References | |
| Download: ML20273A310 (15) | |
Text
Monticello License Amendment Request to Adopt TSTF-564, Rev. 2, Safety Limit MCPR October 2, 2020
Agenda
- Purpose
- Xcel Energy Implementation
- TSTF-564 Background
- Framatome MCPR95/95 Derivation
- MNGP Safety Limit TS
- TSTF-564 Variations
- Summary 2
Discuss proposed License Amendment for the Monticello Nuclear Generating Plant (MNGP) to adopt TSTF-564, Revision 2, Safety Limit MCPR, which includes two variations from TSTF-564.
Purpose 3
- Proposed date for LAR submittal - October 2020
- Requesting normal one year NRC review
- No changes to TS 5.6.3.b critical power correlations or SLMCPR methodology Xcel Energy Implementation 4
TS 2.1.1.2 Safety Limit (SL) MCPR ensures 99.9% of the fuel rods are not susceptible to boiling transition Separate limits for two and single recirculation-loop operation Current SL - referred to as SLMCPR99.9%
TS 2.1.1.2 (NUREG-1433) corresponds 2.1.1.3 in the MNGP TS SLMCPR redefined by TSTF-564 as a cycle-independent fuel design MCPR value dependent on 95/95 statistics of the fuel assembly critical power correlation database - SLMCPR95/95 SLMCPR99.9% dependent on cycle-specific power distribution Used in determination of Operating Limit MCPR in LCO 3.2.2 Documented in Core Operating Limits Report (COLR)
TSTF-564 Background 5
- MCPR95/95 = ECPR x (1 + k95/95s)
- Where: ECPR = Calculated Critical Power Measured Critical Power k = One-sided tolerance limit factor (D. B. Owen) s = Standard deviation of the samples MCPR95/95 Derivation 6
MCPR95/95 Limits for Framatome Fuel MCPR95/95 Derivation 7
Correlation:
SPCB (ATRIUM 10)
ACE ATRIUM 10XM ACE ATRIUM 11 Reference EMF-2209(P)(A) Rev. 3 ANP-10298P-A, Rev. 1 ANP-10335P-A, Rev. 0 Number of Data
[ ]
[ ]
[ ]
Mean ECPR
[ ]
[ ]
[ ]
Standard Deviation
[ ]
[ ]
[ ]
D.B. Owen k95/95
[ ]
[ ]
[ ]
Design Limit 1.04 1.05 1.05
Extended Flow Window (EFW) operating domain implementation (analogous to GE MELLLA+ operating domain) modified the TS SLMCPR with Am. No. 191 Operation in EFW above ratio of power to core flow 42 MWt/ Mlb/hr currently requires 0.03 addition to the SLMCPR value to address power distribution uncertainties (TS 2.1.1.3.c)
TS 2.1.1.3 broken up into 3 conditions to reflect operation in:
Single or two recirculation loop operation Operation above or below this threshold in EFW operating domain MNGP Safety Limit TS 8
MNGP Safety Limit TS 9
TSTF-564 redefined the safety limit as the SLMCPR95/95 for the limiting fuel type This redefinition of the SLMCPR requires discussion to align the Monticello licensing basis with the TSTF This possibility was foreseen when TSTF-564 was developed And is reflected in the NRC safety evaluation for TSTF-564 MNGP Safety Limit TS 10
TSTF-564 safety evaluation Section 3.2 states:
penalties would also continue to be imposed in the determination of the MCPR99.9%, along with any other penalties associated with the process of (or other inputs used in) determining the MCPR99.9% (e.g.,
penalties applied to the MCPR99.9% SL for operation in the Maximum Extended Load Limit Line Analysis Plus (MELLLA+) operating domain).
Inclusion of the SL adder (0.03) in the SLMCPR listed under TS 2.1.1.3 is no longer appropriate with adoption of TSTF-564 The SL adder is already included in the COLR and is taken into account in determination of the OLMCPR This aligns with NRC treatment of penalties in the TSTF-564 SE MNGP Safety Limit TS 11
Under the COLR specification in the TS TS 5.6.3.a. Item 2 - will be revised to specify The MCPR and the MCPR99.9% for Specification 3.2.2 TS 5.6.3.b. Item 24 - will be revised to add ANP-3857P Revision 2, Design Limits for Framatome Critical Power Correlations, July 2020 Under the TS Bases for LCO 3.2.2, MCPR The Applicable Safety Analyses and LCO sections will be revised to reflect the application of 0.03 adder in the determination of the OLMCPR MNGP Safety Limit TS 12
1.
The reactor steam dome pressure is 586 psig versus 785 psig in accordance with the Framatome ACE correlations.
2.
The current SL 0.03 adder will be relocated to be part of the OLMCPR determination in the MCPR specification as discussed in the COLR - aligns with TSTF-564 TSTF-564 Variations 13
Proposed date for LAR submittal - October 2020 MCPR95/95 calculated for Framatomes ATRIUM 10XM fuel type using approved methodology SL 0.03 adder will be applied in OLMCPR determination Summary 14