05000445/LER-2014-002, Regarding Non-Compliance with Pressure-Temperature Limits Report During RCS Vacuum Fill
| ML14101A364 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/03/2014 |
| From: | Flores R, Madden F Luminant Generation Co, Luminant Power |
| To: | Document Control Desk |
| References | |
| CP- 201400384, TXX -14045 LER 14-002-00 | |
| Download: ML14101A364 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 4452014002R00 - NRC Website | |
text
Luminant Rafael Flores Senior Vice President
& Chief Nuclear Officer rafael.flores@Luminant.com Luminant Power P 0 Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254 897 5550 C 817 559 0403 F 254 897 6652 CP-201400384 TXX -14045 April 3, 2014 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Ref. #
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT (CPNPP)
DOCKET NO. 50-446 NON-COMPLIANCE WITH PRESSURE-TEMPERATURE LIMITS REPORT DURING RCS VACUUM FILL LICENSEE EVENT REPORT 445 / 14-002-00
Dear Sir or Madam:
Enclosed is Licensee Event Report (LER) 445/14-002-00, "Non-Compliance With Pressure-Temperature Limits Report During RCS Vacuum Fill," for Comanche Peak Nuclear Power Plant (CPNPP) Unit 1.
This communication contains no licensing basis commitments regarding CPNPP Units 1 and 2.
Should you have any questions, please contact R. A. Slough at (254) 897-5727.
Sincerely, Luminant Generation Company LLC Rafael Flores By:
/Fred W. Madden Director, External Affais Enclosure c -
Marc L. Dapas, Region IV B. K. Singal, NRR Resident Inspectors, Comanche Peak A member of the STARS Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde. Wolf Creek 1~~
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES:01/31/2017 (02-2014)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Comanche Peak Nuclear Power Plant (CPNPP) Unit 1 05000 445 1 OF 4
- 4. TITLE Non-Compliance With Pressure-Temperature Lirits Report During RCS Vacuum Fill
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO.
CPNPP Unit 2 05000446 02 04 2014 2014 002 00 04 03 2014 FACILITY NAME DOCKET NUMBER
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
[
20.2203(a)(3)(i)
LI 50.73(a)(2)(i)(C)
LI 50.73(a)(2)(vii) 1
[] 20.2201(d)
[Z 20.2203(a)(3)(ii)
[
50.73(a)(2)(ii)(A)
[
50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
[] 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
[] 50.73(a)(2)(viii)(B)
E] 20.2203(a)(2)(i)
[]
50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
Ej 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
[
20.2203(a)(2)(ii)
[] 50.36(c)(1)(ii)(A)
E]
50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[] 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4) 100 El 20.2203(a)(2)(iv)
[] 50.46(a)(3)(ii)
[
50.73(a)(2)(v)(B)
E] 73.71(a)(5)
El 20.2203(a)(2)(v)
[] 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
[]
50.73(a)(2)(i)(B)
E]
50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)
Timothy A. Hope, Manager, Regulatory Affairs 254-897-6370CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR I--'3SUBMISSION E
YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
NO DATESUBMIS ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On February 4, 2014, Luminant Power recognized Operating Experience at another station to be potentially applicable to Comanche Peak Nuclear Power Plant (CPNPP). An NRC inspection report described a failure to comply with reactor coolant system (RCS) Pressure/Temperature (PIT) Limits when RCS pressure decreases below 0 pounds per square inch gauge (PSIG). At the time of discovery, CPNPP's Pressure Temperature Limit Report (PTLR) only described pressures equal to or greater than 0 PSIG. However, since early 1996, CPNPP's analyses and procedures allowed drawing a vacuum during RCS refill following refuelings. Therefore, Luminant Power is conservatively reporting RCS pressure below 0 PSIG as a violation of Technical Specification 3.4.3 "RCS Pressure and Temperature (P/T) Limits."
The coordination of the change in RCS operating conditions was less than adequate, in that the associated affected documents were not revised as a result of failing to correctly identify the documents and/or involve all applicable parties, as well as the subtlety of the PTLR pressure value discrepancy. The apparent cause of not maintaining RCS pressure within the limits described in the PTLR was a legacy design implementation error. The apparent mental model by licensed operations personnel was not aligned with the literal applicability of the PTLR curves, in that the curves are applicable during RCS vacuum fill conditions, and not limited to only heat-up, cool-down, and inservice leak/hydrostatic testing conditions. Luminant Power interpreted the PTLR to only apply to RCS pressure conditions above atmospheric pressure, and therefore did not consider it in conflict with the adoption of the vacuum refill analysis and procedure. Corrective actions included revising the PTLR to specify negative 14.7 pounds per square inch gage (PSIG) as the lower limit. The explicit PTLR compliance error during vacuum refill did not adversely affect the health and safety of the public or station personnel.
All times in this report are approximate and Central Daylight Time unless noted otherwise.
(If more space is required, use additional copies of SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES:
On February 4, 2014, Luminant Power recognized Operating Experience at another station to be potentially applicable to Comanche Peak Nuclear Power Plant (CPNPP). An NRC inspection report described a failure to comply with reactor coolant system (RCS) Pressure/Temperature (P/T) Limits when RCS pressure decreases below 0 pounds per square inch gauge (PSIG). At the time of discovery, CPNPP's Pressure Temperature Limit Report (PTLR) only described pressures equal to or greater than 0 PSIG. However, since early 1996, CPNPP's analyses and procedures allowed drawing a vacuum during RCS refill following refuelings. Therefore, Luminant Power is conservatively reporting RCS pressure below 0 PSIG as a violation of Technical Specification 3.4.3 "RCS Pressure and Temperature (PIT) Limits."
The coordination of the change in RCS operating conditions was less than adequate, in that the associated affected documents were not revised as a result of failing to correctly identify the documents and/or involve all applicable parties, as well as the subtlety of the PTLR pressure value discrepancy. The apparent mental model by licensed operations personnel was not aligned with the literal applicability of the PTLR curves, in that the curves are applicable during RCS vacuum fill conditions, and not limited to only heat-up, cool-down, and inservice leak/hydrostatic testing conditions. Luminant Power interpreted the PTLR to only apply to RCS pressure conditions above atmospheric pressure, and therefore did not consider it in conflict with the adoption of the vacuum refill analysis and procedure. Corrective actions included revising the PTLR to specify negative 14.7 pounds per square inch gage (PSIG) as the lower limit. The explicit PTLR compliance error during vacuum refill did not adversely affect the health and safety of the public or station personnel.
(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
CPNPP Operating Procedures SOP-101 A, "Reactor Coolant System", for Unit 1, and SOP-101 B, "Reactor Coolant System", for Unit 2, ensure sufficient RCS pressure to assure adequate net positive suction head (NPSH) for the RHR system, over an operating band of temperatures, pressures, and RHR flows.
Therefore, the explicit PTLR compliance error during vacuum refill did not adversely affect the health and safety of the public or station personnel.
IV. CAUSE OF THE EVENT
The coordination of change in RCS operating conditions was less than adequate, in that the associated affected documents were not revised as a result of failing to correctly identify the documents and/or involve all applicable parties, as well as the subtlety of the PTLR pressure value discrepancy. Luminant Power interpreted the PTLR to only apply to RCS pressure conditions above atmospheric pressure, and therefore did not consider it in conflict with the adoption of the vacuum refill analysis and procedure.
V.
CORRECTIVE ACTIONS
On April 1, 2014, the Comanche Peak Nuclear Power Plant Pressure and Temperature Limits Report, Revision 3 became effective, which includes figures showing acceptable operation down to -14.7 PSIG.
VI. PREVIOUS SIMILAR EVENTS
There have been no previous similar reportable events at CPNPP in the last three years.
NRC FORM 386A 102.20141 PRINTED ON RECYCLED PAPERPRINTED ON RECYCLED PAPER