05000341/LER-2019-001, Unplanned Loss of Safety Function of Gland Seal Exhauster Trip During Planned Maintenance Due to Inadequate Procedure

Unplanned Loss of Safety Function of Gland Seal Exhauster Trip During Planned Maintenance Due to Inadequate Procedure

ML19060A290
Person / Time
Site:	Fermi
Issue date:	03/01/2019
From:	Fessler P DTE Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-19-0011 LER 2019-001-00
Download: ML19060A290 (6)

LER-2019-001, Unplanned Loss of Safety Function of Gland Seal Exhauster Trip During Planned Maintenance Due to Inadequate Procedure

Event date:
Report date:
Reporting criterion:	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)(i) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x)
3412019001R00 - NRC Website

text

Paul Fessler Senior Vice President and Chief Nuclear Officer DTE Energy Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.4153 Fax: 734.586.1431 Email: Paul.Fessler@dteenergy.com DTE 10 CFR 50.73 March 1, 2019 NRC-19-0011 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001

Reference:

Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

Subject:

Licensee Event Report (LER) No. 2019-001 Pursuant to 10 CFR 50.73(a)(2)(v)(C) and (D), DTE Electric Company (DTE) is submitting LER No. 2019-001, Unplanned Loss of Safety Function of Gland Seal Exhauster Trip During Planned Maintenance Due to Inadequate Procedure.

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, Paul essl r Senior Vice President and CNO

Enclosure:

Licensee Event Report No. 2019-001, Unplanned Loss of Safety Function of Gland Seal Exhauster Trip During Planned Maintenance Due to Inadequate Procedure

USNRC NRC-19-0011 Page 2 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-19-0011 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Licensee Event Report (LER) No. 2019-001 Unplanned Loss of Safety Function of Gland Seal Exhauster Trip During Planned Maintenance Due to Inadequate Procedure

NRC FORM 366 (04-2018)

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

(See Page 2 for required number of digits/characters for each block)

(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)

APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

NRC FORM 366 (04-2018) 05000

3. Page 1

OF

4. Title

5. Event Date Month Day Year

6. LER Number Year Sequential Number Rev No.

7. Report Date Month Day Year

8. Other Facilities Involved Facility Name Docket Number 05000 Facility Name Docket Number 05000

9. Operating Mode

10. Power Level

11. This Report is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply) 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A) 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(ix)(A) 50.73(a)(2)(x) 73.71(a)(4) 73.71(a)(5) 73.77(a)(1) 73.77(a)(2)(i) 73.77(a)(2)(ii)

Other (Specify in Abstract below or in Page of 05000-

3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.

SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS

The GSE trip was declared inoperable for a very short period during the planned maintenance evolution to reset the FW DCS. The reset of FW DCS was a planned maintenance activity and performed in accordance with site procedures. The FW DCS and GSE trip systems both functioned as expected per design. In addition, the relevant TS for RWM and the GSE trip were entered and required actions were performed as applicable. No TS allowable times were exceeded during the event.

As described above, no control rod movement took place during the time that the GSE trip was inoperable. This compensatory measure due to planned inoperability of RWM would reduce the probability of CRDA occurrence.

Engineering evaluation of the control rod positions at the time of event determined that the control rod worths were insufficient to result in fuel damage even if a postulated CRDA had occurred.

In addition, although the GSE trip was inoperable, engineering evaluation determined that plant conditions at the time met the regulatory limits even without crediting a GSE trip. Specifically, with the plant at 5.2% power, with control room emergency filtration (CREF) operable, and with a delay time since last shutdown of approximately 24 days, doses were well within regulatory limits without any reliance on the GSE trip. For this reason, the GSE trip was not necessary to perform any safety function during the brief period, 1 minute 19 seconds, when it was inoperable on January 1, 2019 during the FW DCS reset for maintenance.

Therefore, there was no adverse impact to public health and safety or to plant employees. There were no radiological releases.

CAUSE OF THE EVENT

The cause of the unplanned GSE inoperability was the interruption of the steam and feedwater flow signals used by the GSE instrumentation due to the planned maintenance activity for FW DCS reset.

The cause of the GSE trip inoperability being unplanned was that the impact on the automatic trip instrumentation for the GSE, while halting the FW DCS processors, was not fully documented in site procedures and the applicable WO prior to implementation of the WO. Although there were procedures for the FW DCS that included the impact on the RWM, there was no procedural guidance that addressed the impact on the GSE trip function or that referenced the applicable GSE trip TS LCO 3.3.7.3.

There were no component failures during this event.

CORRECTIVE ACTIONS

No corrective action was required to restore GSE trip operability; operability was automatically restored by design upon successful restart of FW DCS.

Station alarm response and system operating procedures were revised on or before January 11, 2019 to explicitly reference the impact of the FW DCS on the GSE trip and provide explicit reference to TS 3.3.7.3. These procedure revisions provide guidance to address the potential impacts of FW DCS maintenance activities on the GSE trip function and relevant TS. An additional future action includes revision of the applicable maintenance procedure.

PREVIOUS OCCURRENCES

No previous site occurrences of reportable conditions were identified with the GSE trip function.

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