05000458/LER-2018-008, Potential Loss of Safety Function and Unanalyzed Cond It Ion Due to Legacy Design Deficiency in Control Building HVAC
| ML18324A744 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 11/20/2018 |
| From: | Maguire W Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RBG-47915 LER 2018-008-00 | |
| Download: ML18324A744 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2) 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)(8) 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 4582018008R00 - NRC Website | |
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Entergx RBG-47915 November 20, 2018 Attn: Document Control Desk U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2738
Subject:
Dear Sir or Madam:
Licensee Event Report 50-458 I 2018-008-00 River Bend Station, Unit 1 Docket No. 50-458 License No. NPF-47 Entergy Operations, Inc.
River Bend Station 5485 U S Highway 61N St. FranCisville. LA 70775 Tel 225-381-4374 William F. Maguire Site Vice President In accordance with 10 CFR 50.73, enclosed is the subject Licensee Event Report. This document contains no commitments. If you have any questions, please contact Mr. Tim Schenk at 225-381 -4177.
Sincerely, WFM/twf Enclosure cc:
(with Enclosure)
U.S. Nuclear Regulatory Commission Attn: Ms. Lisa M. Regner, Project Manager 09-0-14 One White Flint North 11555 Rockville Pike Rockville, MD 20852 U.S. Nuclear Regulatory Commission Region IV 1600 East Lamar Blvd.
Arlington, TX 76011 -4511
RBG-47915 Page 2 of 2 NRC Senior Resident Inspector Attn: Mr. Brian Parks 5485 U.S. Highway 61, Suite 1 St. Francisville, LA 70775 Public Utility Commission of Texas Attn: PUC Filing Clerk 1701 N. Congress Avenue P. O. Box 13326 Austin, TX 78711-3326 INPO (via ICES reporting)
RBF1 0213
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150~104 EXPIRES: 0313112020 (04-2018)
Estimated burden per response to IXlITlpty with thl' mandatory collection request 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.
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LICENSEE EVENT REPORT (LER)
Reported lessons learned are Incorporated Into the lcensing proces, and fed book to
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Industry. Send comment. regarcfng blXden esllma!! tD the Informatton SeMce. Br.r1ch 0.,.
(T.2 F43), U.S. Nudear Regulatory Comml.. kln, WasNnglDn, DC 20555-0001, or by e-mail
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(See Page 2 for required number of digits/characters for each block)
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S tD Infocolects.ReSOlXCO@nrc.gov, and to the Desk OfIcer, 0flIce of Information and (See NUREG-1022, R.3 for instruction and guidance for completing this form Regulatory Affairs, NEOB-l0202, (315t).l)1D4), Oflice of Management and 8udge~
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- 3. Page R iver Bend Station -
Unit 1 458 3
05000 1
OF
- 4. Title Potential Loss of Safety Function and Unanalyzed Condition due to Legacy Design Deficiency in Control Building HVAC.
- 5. Event Date
- 6. LER Number
- 7. Report Date
- 8. Other Facilities Involved Month Day Year Year I Sequential I Rev Month Day Fa.llily Name Docket NumbDr Number No.
Year NA 05000 NA 09 25 2018 2018 Fa.1l11y Name Do.ket Number 08 -
00 11 20 2018 NA 05000 NA
- 9. Operating Mode
- 11. This Report Is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply)
D 20.2201 (b)
D 20.2203(a)(3)(1)
D 50.73(a)(2)(iI)(A)
D 50.73(a)(2)(vlll)(A)
D 20.2201 (d)
D 20.2203(a)(3)(1I) 0 50.73(a)(2)(1I)(8)
D 50.73(a)(2)(vlil)(8) 1 D 20.2203(a)(1 )
D 20.2203(a)(4)
D 50.73(a)(2)(III)
D 50.73(a)(2)(lx)(A)
D 20.2203(a)(2)(I)
D 50.36(c)(1 )(I)(A)
D 50.73(a)(2)(lv)(A)
D 50.73(a)(2)(x)
- 10. Power Level D 20.2203(a)(2)(II)
D 50.36(c)(1 )(II)(A)
D 50.73(a)(2)(v)(A)
D 73.71(a)(4)
D 20.2203(a)(2)(III)
D 50.36(c)(2)
D 50.73(a)(2)(v)(8)
D 73.71 (a)(5)
D 20.2203(a)(2)(lv)
D 50.46(a)(3)(II)
D 50.73(a)(2)(v)(C)
D 73.77(a)(1 )
90 D 20.2203(a)(2)(v)
D 50.73(a)(2)(I)(A) 0 50.73(a)(2)(v)(D)
D 73.77(a)(2)(I)
D 20.2203(a)(2)(vl) 0 50.73(a)(2)(I)(B)
D 50.73(a)(2)(vll)
D 73.77(a)(2)(II)
D 50.73(a)(2)(I)(C)
D Other (Specify in Abstract below or in CORRECTIVE ACTION TO PREVENT RECURRENCE Compensatory measures were put in place so that only HVK Chiller 'C' or HVK Chiller '0' could be the running or standby Chiller until a temporary modification was put in place to bypass the Quick Restart timer in the HVK Chiller 'A' and HVK Chiller '8' start logic. If either HVK Chiller 'A' or HVK Chiller '8' was already running and had been running for longer than 20 minutes, then it was allowed to continue to run.
IA temporary modification to bypass the quick restart timer in the HVK Chiller 'A' and HVK Chiller '8' start logic was installed in October 2018. Administrative controls were put in place to restrict operators from unnecessarily restarting the Chillers within 20 minutes of a previous start.
Procedure revisions were made to restrict operators from restarting a Chiller before 20 minutes have elapsed from the previous start. An additional procedure change was made so that following a LOP, if a Chiller is restarted within 20 minutes of the previous start, that Chiller must be run for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or secured for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to allow the motor to cool before another start attempt.
An extent of condition for HVK single failure vulnerabilities and design deficiencies was performed. No new vulnerabilities were identified.
A permanent modification will be performed to eliminate the HVK control logic deficiency and is being tracked by the Corrective Action Program.
PREVIOUS OCCURRENCE EVALUATION A similar HVK control logic vulnerability event was identified in April 2018 and reported by LER-2018-001 on June 7, 2018.
SAFETY SIGNIFICANCE
In the unlikely event of a LOP within 20 minutes of an HVK Chiller 'A' or HVK Chiller '8' start and a single failure in the opposite division, control room operators would have responded to the event with established procedures for a loss of Control 8uilding Ventilation to restore the safety function with either HVK Chiller 'C' or HVK Chiller '0'. Thus, this event was of minimal significance to the health and safety of the public.
(NOTE: Energy Industry Identification System component function identifier and system name of each component or system referred to in the LER are annotated as (**XX**) and [XX]. respectively.) Page 3
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