DCL-13-077, CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2012
| ML13212A143 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/30/2013 |
| From: | Allen B Pacific Gas & Electric Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| DCL-13-077 | |
| Download: ML13212A143 (7) | |
Text
Pacific Gas and Electric Company July 30, 2013 PG&E Letter DCL-13-077 Barry S. Allen Site Vice President Diablo Canyon Power Plant Mail Code 104/6 P. o. Box 56 Avila Beach. CA 93424 805.545.4888 Internal: 691.4888 Fax: 805.545.6445 u.s. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 10 CFR 50.46 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2
. 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2012
Dear Commissioners and Staff:
Pursuant to 10 CFR 50.46, the enclosure to this letter is the annual report of changes in the Westinghouse emergency core cooling system evaluation models that affect peak cladding temperature (PCT) calculations for Pacific Gas and Electric Company's (PG&E's) Diablo Canyon Power Plant, Units 1 and 2.
The attachments to the enclosure provide a summary of the PCT margin allocations and their bases.
PG&E makes no new or revised regulatory commitments (as defined by NEI 99-04) in this report.
If you have questions regarding this submittal please contact Mr. Steve Baker at 805-545-6742.
Sincerely,
~75.~
Barry S. Allen dh06/6038/64077331 Enclosure cc/enc: Thomas R. Hipschman, NRC Senior Resident Inspector Arthur T. Howell III, NRC Region IV James T. Polickoski, NRR Project Manager Diablo Distribution A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onofre
- South Texas Project
- Wolf Creek
Enclosure PG&E Letter DCL-13-077 ANNUAL REPORT OF EMERGENCY CORE COOLING SYSTEM EVALUATION MODEL CHANGES FOR PEAK CLADDING TEMPERATURE Pursuant to 10 CFR 50.46, this enclosure provides an annual report of changes in the Westinghouse emergency core cooling system (ECCS) evaluation models that affect peak cladding temperature (PCT) calculations for Pacific Gas and Electric Company's (PG&E's) Diablo Canyon Power Plant (DCPP), Units 1 and 2.
This report is based on changes described in Westinghouse Letter L TR-LlS-13-61, "Diablo Canyon Units 1 and 2 10 CFR 50.46 Annual Notification and Reporting for 2012," dated February 28, 2013.
Attachment A contains Unit 1 small-break loss-of-coolant accident (SBLOCA) and best-estimate, large-break loss-of-coolant accident (BELOCA) PCT Margin Utilization sheets. Attachment B contains the corresponding Unit 2 data. There have been no changes in the SBLOCA PCT results for either Unit 1 or Unit 2 since the last annual update. We provided the last annual update in PG&E Letter DCL-12-070, "10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2011," dated July 19, 2012. There have been no changes in the BELOCA PCT results for either Unit 1 or Unit 2 since the 30-Day Notification Report provided in PG&E Letter DCL-12-1 02, "10 CFR 50.46 30-Day Notification Report of Significant Emergency Core Cooling System Evaluation Model Changes that Affect Peak Cladding Temperature," dated October 18, 2012.
The final net PCT values are listed below for each unit. Two PCT values are reported for the Unit 1 BELOCA results. The two BELOCA PCT values are labeled Reflood 1 and Reflood 2, as they represent the two distinctive PCT peaks that occur during the reflood phase for the Unit 1 BELOCA Code Qualification Document methodology. The Unit 2 BELOCA reports only one PCT value consistent with the BELOCA ASTRUM methodology.
SBLOCA BELOCA Unit 1: 1391 of (no change)
Unit 2: 1288°F (no change)
Reflood 1 Reflood 2 2005°F (no change) 2095°F (no change) 2097° F (no change)
The PCT values remain within the 2200°F limit specified in 10 CFR 50.46.
However, because Unit 1 and Unit 2 BELOCA have a total PCT margin allocation that is currently greater than 50°F, and in order to coordinate with the 24-month fuel cycle project schedule, PG&E will complete the Unit 1 BELOCA reanalysis and provide the updated PCT results to the NRC by December 2016, as stated in 1
Enclosure PG&E Letter DCL-13-077 PG&E Letter DCL-12-1 02. Also, PG&E will complete the Unit 2 BELOCA reanalysis and provide the updated PCT results to the NRC by December 2016.
2
A.
B.
C.
D.
E.
Attachment A PG&E Letter DCL-13-077 DCPP UNIT 1 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION SMALL-BREAK LOCA PG&E Letter 1 ANAL YSIS OF RECORD PCT=
1391°F DCL-09-057 PRIOR 10 CFR 50.46 ECCS MODEL ASSESSMENTS2
- 1.
None i1PCT =
OaF 10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1.
None i1PCT =
OaF SUM OF 10 CFR 50.46 CHANGES
- 1.
Net Sum of 10 CFR 50.46 PCT Changes i1PCT =
OaF
- 2.
Absolute Sum of 10 CFR 50.46 PCT Changes i1PCT =
OaF Analysis of Record PCT (Line A)
+ Line 0.1 Net Sum of 1391°F 10 CFR 50.46 PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remains less than 2200°F.
2 For those issues that have been previously reported under 10 CFR 50.46, a PG&E letter number is listed.
Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current LOCA model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
A-1
A.
B.
C.
D.
E.
Attachment A PG&E Letter DCL-13-077 DCPP UNIT 1 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION BELOCA PG&E Letter1 Reflood 1 Reflood 2 ANAL YSIS OF RECORD 1900°F 1860°F DCL-05-146
~PCT
~PCT PRIOR 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. Revised blowdown heatup 5°F 5°F DCL-05-086 uncertainty distribution.
- 2. HOTSPOT Fuel Relocation 10°F O°F DCL-07-071 Error.
- 3. Replacement Steam 75°F 71°F DCL-09-057 Generators
- 4. 230 kV Degraded Voltage Event O°F 39°F DCL-11-082 10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1. Performance and Design (PAD)
-118°F
-118°F DCL-12-102 4.0 Implementation
- 2. Fuel thermal conductivity 133°F 238°F DCL-12-102 degradation (TCD) and Peaking Factor Burndown SUM OF 10 CFR 50.46 CHANGES
- 1. Net Sum of PCT Changes 105°F 235°F
Line 0.1 Net Sum of 10 CFR 50.46 2005°F 2095°F PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remains less than 220QoF.
2 For those issues that have been previously reported under 10 CFR 50.46, a PG&E letter number is listed.
Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current LOCA model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
A-2
Attachment B PG&E Letter DCL-13-077 DCPP UNIT 2 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION SBLOCA PG&E Letter 1 A.
ANAL YSIS OF RECORD PCT=
1288°F DCL-08-061 B.
PRIOR 10 CFR 50.46 ECCS MODEL ASSESSMENTS2
- 1. None
~PCT=
O°F C.
10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1. None
~PCT=
O°F D.
SUM OF 10 CFR 50.46 CHANGES
- 1. Net Sum of 10 CFR 50.46 PCT Changes
~PCT=
O°F
- 2. Absolute Sum of 10 CFR 50.46 PCT Changes
~PCT=
O°F E.
Analysis of Record PCT (Line A)
+ Line 0.1 Net Sum of 1288°F 10 CFR 50.46 PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remains less than 2200°F.
2 For those issues that have been previously reported under 10 CFR 50.46, a PG&E Letter number is listed.
Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current LOCA model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
B-1 PG&E Letter DCL-13-077 DCPP UNIT 2 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION BELOCA A.
ANALYSIS OF RECORD B.
PRIOR 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. HOTSPOT Fuel Relocation Error.
- 2. 230 kV Degraded Voltage Event C.
10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1. Fuel TCD and Peaking Factor Burndown D.
SUM OF 10 CFR 50.46 CHANGES
- 1. Net Sum of 10 CFR 50.46 PCT Changes
- 2. Absolute Sum of 10 CFR 50.46 PCT Changes E.
Analysis of Record PCT (Line A) +
Line 0.1 Net Sum of 10 CFR 50.46 PCT Changes PCT=
ilPCT=
ilPCT=
ilPCT ilPCT=
ilPCT=
PG&E Letter1 DCL-07-071 DCL-07-071 DCL-11-082 DCL-12-102 The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remains less than 2200°F.
2 For those issues that have been previously reported under 10 CFR 50.46, a PG&E letter number is listed.
Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current LOCA model issues are not considered with respect to 10 CFR 50.46 reporting req u irements.
8-2