05000416/LER-1917-004, Regarding Outside-of-Tech-Spec-Allowable-Value Automatic Depressurization System (ADS) Initiation Timer Relay Because of Age Degradation
| ML17194A844 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 07/13/2017 |
| From: | Ellis D Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GNRO-2017/00046 LER 17-004-00 | |
| Download: ML17194A844 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4161917004R00 - NRC Website | |
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~Entergy GNRO-2017/00046 July 13, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Entergy Operations, Inc.
P.o. Box 756 Port Gibson, MS 39150 David R Ellis Acting Regulatory Assurance Manager Grand Gulf Nuclear Station Tel. (601) 437-2489
SUBJECT:
Outside-of-Tech-Spec-Allowable-Value Automatic Depressurization System (ADS) initiation timer relay because of age degradation.
Docket No. 50-416 License No. NPF-29
Dear Sir or Madam:
Attached is Licensee Event Report (LER) 2017-004-00, Outside-of-Tech-Spec-Allowable-Value Automatic Depressurization System (ADS) initiation timer relay because of age degradation, which is a final report.
This letter contains no new commitments. Should you have any questions or require additional information, please contact David Ellis at (601) 437-2489.
Sincerely, e::::......--
David R Ellis Acting Regulatory Assurance Manager Grand Gulf Nuclear Station DRE/amh Attachment: Licensee Event Report (LER) 2017-004-00.
cc: (See Next Page)
GNRO-2017/00046 Page 2 of 2 cc: with Attachment and Enclosures Mr. John P. Boska, Project Manager Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8-C2 Washington, DC 20555 Mr. Kriss M. Kennedy U.S. Nuclear Regulatory Commission Regional Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 Mr. Siva Lingham U.S. Nuclear Regulatory Commission Mail Stop OWFN 8 B1 Rockville, MD 20852-2738 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150
Attachment Licensee Event Report (LER) 2017-004-00.
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2017)
, the NRC may not conduct or
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- 13. PAGE Grand Gulf Nuclear Station, Unit 1 05000416 1 OF 3
- 4. TITLE Outside-of-Tech-Spec-Allowable-Value Automatic Depressurization System (ADS) initiation timer relay because of age degradation.
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR N/A 05000 N/A FACILITY NAME DOCKET NUMBER OS 26 2017 2017 - 004 - 00 07 13 2017 N/A 05000 N/A 11.THISREPORTISSUBMITTEDPURSUANTTO THEREQUIREMENTS OF 10 CFR§: (Check all that apply)
MODE 1 o 20.2201(d) o 20.2203(a)(3)(ii) o SO.73(a)(2)(ii)(B) o SO.73(a)(2)(viii)(B) o 20.2203(a)(1) o 20.2203(a)(4) o SO.73(a)(2)(iii) o SO.73(a)(2)(ix)(A) o 20.2203(a)(2)(i) o SO.36(c)(1 )(i)(A) o SO.73(a)(2)(iv)(A) o SO.73(a)(2)(x) o 20.2203(a)(2)(ii) o SO.36(c)(1 )(ii)(A) o SO.73(a)(2)(v)(A) o 73.71(a)(4)
- 10. POWER LEVEL o 20.2203(a)(2)(iii) o SO.36(c)(2) o SO.73(a)(2)(v)(B) o 73.71(a)(S) o 20.2203(a)(2)(iv) o SO,46(a)(3)(ii) o SO.73(a)(2)(v)(C) o 73.77(a)(1) 100 o 20.2203(a)(2)(v) o SO.73(a)(2)(i)(A) o SO.73(a)(2)(v)(D) o 73.77(a)(2)(i) o 20.2203(a)(2)(vi)
I8IS0.73(a)(2)(i)(B) o SO.73(a)(2)(vii) o 73.77(a)(2)(ii) o SO.73(a)(2)(i)(C) o OTHER Specify in Abstract below or in =
- 2. DOCKET 05000416 YEAR I
- 3. LER NUMBER SEQUENTIAL NUMBER 2017 - 004 - 00 I
REV.
NO.
DESCRIPTION
On May 26, 2017, while performing Automatic Depressurization System (ADS) quarterly surveillance, the time delay on the ADS initiation timer relay was found outside of its technical specification allowable value of S; 115 seconds, as documented in the corrective action program.
The failure mechanism is the degradation of timing function for the ADS initiation timer relay that delays initiation of ADS in order to allow time for high pressure injection to restore reactor water level. The technical specification allowable value for this timer is less than or equal to 115 seconds.
The as found value was beyond this value, indicating that this timer was inoperable prior to the adjustment. This surveillance is performed on a quarterly basis. This same condition was found during the last surveillance on February 23, 2017. The surveillance performed prior to that on 11/18/2016 had as founds that were within tolerance.
Automatic Depressurization System is required in modes 1, 2, and 3 with the reactor above 150 psig. Therefore this function was not required from November 18, 2016 to January 30, 2017, which is when the reactor reached 150 psig in mode 2. Between November 18, 2016 and January 30, 2017 plant was in Mode 4.
Automatic Depressurization System initiation is accomplished by energization of either the Division 1 or Division 2 solenoids associated with each of the ADS valves. The logic for each division is separate.
Therefore, the automatic safety function would still be accomplished within the allowable time provided that the Division 2 system was Operable. The Division 2 initiation logic was taken out of service on March 10, 2017, to support performance of surveillance 06-EL-1 B21-0-0001. In order to determine if the Division 1 logic would have initiated within the allowable time during the period when the Division 2 logic was inoperable, an additional review was performed. The average rate of change of the setpoint between surveillances was 0.402 seconds/day for the first interval (November 18, 2016 - February 23, 2017) and 0.424 seconds/day for the second interval (February 23, 2017 - May 26, 2017). Use of the larger rate of change is conservative, and therefore a rate of 0.424 seconds/day was assumed. Linearly extrapolating from an as left condition of 104 seconds on February 23, 2017, it is concluded that the setpoint would have been 110.4 seconds on March 10, 2017. This value is within the 115 second TS AV. Therefore it is concluded that no loss of safety function would have occurred for this condition. The linearity assumption was validated as conservative on subsequent calibration.
REPORTABILITY
This event is reportable as a license event report (LER) in accordance with NUREG-1022, Section 3.2.2, and 10CFR50.73(a)(2)(i)(B), because it was a "condition prohibited by Technical Specifications."
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, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
NRC FORM (6-2016) 366A U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://wwvy.nrc.gov/reading-rm/doc-eolleetions/nuregs/staff/sr10221Qn APPROVED BY OMB: NO. 3150-0104 EXPIRES: 3/31/2020
- 1. FACILITY NAME Grand Gulf Nuclear Station, Unit 1 NARRATIVE
- 2. DOCKET 05000416 YEAR I
- 3. LER NUMBER SEQUENTIAL NUMBER 2017 - 004 - 00 I
REV.
NO.
CAUSE
The cause of the failure mechanism is the degradation of timing function for the ADS initiation timer relay 1821-K5A. The degradation of the timer relay is most likely due to the electrolytic capacitors.
This section will be supplemented upon completion of the analysis.
CORRECTIVE ACTIONS
The event was entered into the Grand Gulf Nuclear Station corrective action program and the causal analysis is ongoing.
SAFETY SIGNIFICANCE
There were no nuclear safety consequences or radiological consequences as a result of this event. No Technical Specification Safety Limits were violated.
This section will be supplemented upon completion of the analysis.
PREVIOUS SIMILAR OCCURRENCES LER 2017-002-00 Loss of Secondary Containment and Inoperability of the Standby Gas Treatment Systems.
LER 2015-003-00 Technical Specification Surveillance on Primary Containment Isolation Valves.
LER 2016-008-00 Entry into Mode of Applicability with the Alternate Decay Heat Removal System Inoperable.
LER 2016-009-00 Entry into Mode of Applicability with the Oscillation Power Range Monitor Upscale Settings Incorrectly Set.
The identified licensee event reports were reviewed and it has been determined that the causes and corrective actions for the previously identified events were sufficiently different that they could not have predicted or prevented the occurrence of this event.
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