05000341/LER-2017-001, Regarding Loss of Reactor Protection System Scram Function During the Main Steam Isolation Valve and Turbine Stop Valve Channel Functional Tests Due to Use of a Test Box
| ML17065A226 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 03/06/2017 |
| From: | Polson K DTE Electric Company |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC-17-0018 LER 17-001-00 | |
| Download: ML17065A226 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 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)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 3412017001R00 - NRC Website | |
text
DTE Energy 10 CFR 50.73 March 6, 2017 NRC-17-0018 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0009
Reference:
Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43
Subject:
Licensee Event Report (LER) No. 2017-001 Pursuant to 10 CFR 50.73(a)(2)(v)(A) and (D), DTE Electric Company (DTE) is submitting LER No. 2017-001, Loss of Reactor Protection System Scram Function During the Main Steam Isolation Valve and Turbine Stop Valve Channel Functional Tests due to Use of a Test Box.
No new commitments are being made in this LER.
Should you have any questions or require additional information, please contact Mr. Scott A. Maglio, Manager - Nuclear Licensing, at (734) 586-5076.
Sincerely, Keith J. Polson Site Vice President
Enclosure:
Licensee Event Report No. 2017-001 cc: NRC Project Manager NRC Resident Office Reactor Projects Chief, Branch 5, Region III Regional Administrator, Region III Michigan Public Service Commission Regulated Energy Division (kindschl@michigan.gov)
Enclosure to NRC-17-0018 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Licensee Event Report (LER) No. 2017-001
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3160-0104 EXPIRES: 1013112018 (06-2016)
Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.
Reported lessons learned are incorporated into the licensing process and fed back to industry.
LICENS E EVENT REPORT (LER)
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections LE E
N RBranch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail (See Page 2 for required number of digits/characters for each block) to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a (See NUREG-1022, R.3 for instruction and guidance for completing this form means used to impose an information collection does not display a currently valid 0MB control Nt ww r
- - id o
ns/nareoslstat~r 221x1 number, the NRC may not conduct or sponsor, and a person is not required to respond to, the htl~j/ww nc avredng-m~dG-clleton~nur~Ib~ffhr1Q22r ~
information collection.
- 3. PAGE Fermi 2 05000 341 1 OF 4
- 4. TITLE Loss of Reactor Protection System Scram Function During Main Steam Isolation Valve and Turbine Stop Valve Channel Functional Tests due to Use of a Test Box
- 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 NUMER NUMBER-NO____
N/A 05000 FACILITY NAME DOCKET NUMBER 01 06 2017 2017 -
001 00 03 06 2017 N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 0 20.2201(b) 20.2203(a)(3)(i)
[] 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2201(d) 20.2203(a)(3)(ii)
E]50.73(a)(2)(ii)(B)
Q 50.73(a)(2)(viii)(B) 1 D 20.2203(a)(1) 20.2203(a)(4)
E 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A)
Q 50.73(a)(2)(iv)(A) 50.73(a)(2)(x)
- 10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A)
/
50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(iv) 50.46(a)(3)(ii)
E 50.73(a)(2)(v)(C) 73.77(a)(1) 100 20.2203(a)(2)(v) 50.73(a)(2)(i)(A)
/
50.73(a)(2)(v)(D) 73.77(a)(2)(i) 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii)
Ej73.77(a)(2)(ii) 50.73(a)(2)(i)(C)
[
OTHER Specify in Abstract below or in The RPS has two independent trip systems (A and B) with two logic channels in each trip system: channels Al and A2, B1 and B2. The use of the RPS test box, as implemented in the procedures at the time of their use in September 2016, would bypass valve position inputs for one trip logic channel preventing the trip logic channel from being in a tripped condition (half-scram). For Function 5, the logic used ensures a full reactor scram occurs for the condition where at least one MSIV in three or more MSLs are less than 90% open. This occurs as the logic uses valves A and B for the Al trip logic, C and D for the A2 trip logic, A and C for the B1 trip logic, and B and D for the B2 trip logic. For Function 9, the logic used ensures a full reactor scram occurs for the condition where three or more TSVs are less than 90% open. The use of the RPS test box, as implemented in September 2016, would still result in a half-scram for the trip system under test because each trip logic channel (Al, A2, B1, B2) individually produces a half-scram. Thus, the entire logic would have remained capable of initiating a full reactor scram. However, the TS 3.3.1.1 Bases requirement of 3 valve position signals per trip system was temporarily (for the duration of test) not met.
Technical Specification 3.3.1.1 Condition C requires restoring RPS trip capability. For Function 5, this would require both trip systems to have each channel associated with the MSIVs in three main steam lines (not necessarily the same main steam lines for both trip systems) OPERABLE or in trip (or the associated trip system in trip). For Function 9, this would require both trip systems to have three channels representing three TSVs, each OPERABLE or in trip (or the associated trip system in trip).
The required action and completion time for TS 3.3.1.1 CONDITION C:
C. REQUIRED ACTION - Restore RPS trip capability, COMPLETION TIME - 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Condition C was applicable to both the MSIV and TSV RPS logic functional testing.
The longest time the test box was installed during the performance surveillances was 55 minutes for the MSIV surveillance and 57 minutes for the TSV surveillance. TS 3.3.1.1 Required Action C was not intentionally entered during the performance of the surveillance but was met each time.
The surveillance procedural error was identified by the Operations Shift Engineer in January 2017 during the work control review for the next scheduled surveillance. Procedures 24.137.01 and 24.110.05 were subsequently revised to not use the test box for future surveillance tests.
Each surveillance procedure was performed once in September 2016 before the error was recognized in January 2017.
The procedures were revised and subsequently performed correctly during the next surveillance test in January 2017.
CAUSE OF THE EVENT
Procedures 24.137.01 and 24.110.05 were revised in August of 2016, to include use of the test box. Neither the procedure Technical Review nor the 10 CFR 50.59 evaluation recognized that use of the RPS test box in procedures 24.137.01 (MSIV) and 24.110.05 (TSV), resulted in bypassing the parallel contacts of multiple trip relays associated with the MSIVs or TSVs closure. In the test condition, the number of operable channels in both MSIV and TSV RPS trip systems was reduced such that the RPS trip capability was not maintained as described by the TS 3.3.1.1 Bases.
While the requirement of having 3 valve position signals per trip system to maintain the RPS trip capability was recognized during preparation of the 10 CFR 50.59 evaluation, the understanding of how this requirement translates to relay contact logic development and the complexities introduced by the parallel logic strings was not identified. The failure to recognize the unique attributes of this logic and the impact of the procedure revisions are considered a human performance error by the engineering and operations staff.
CORRECTIVE ACTIONS
The procedures 24.137.01 and 24.110.05 were revised to remove the use of the test box during future surveillance tests.
Subsequently, on January 7 and 9, 2017, respectively, the procedures for the TSVs and the MSIVs were performed successfully without the use of the test box.
A site wide Human Performance Event reset was conducted to communicate lessons learned from this event.
Additional coaching will be performed for Engineering and Operations personnel on lessons learned when conducting procedure changes such as: (1) supporting applicable Licensing Basis documents need to be reviewed, (2) supporting evaluations need to be adequately intrusive and to the required depth, (3) risk needs to be articulated, and (4) cross organizational expertise needs to be proactively sought before proceeding with the procedure change.
In addition, project plans will be modified to communicate and implement lessons learned for a planned future application of a MSIV isolation logic test box.
PREVIOUS OCCURRENCES
None.Page 4
of 4