05000498/LER-1917-002, Regarding Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil

Regarding Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil

ML18022A786
Person / Time
Site:	South Texas
Issue date:	01/22/2018
From:	Connolly J South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-18003546, STl 34591589 LER 17-002-00
Download: ML18022A786 (8)

LER-1917-002, Regarding Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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)(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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)
4981917002R00 - NRC Website

text

South li!.i.1S Pro/ect lkctrtc Ge11emtt1w s1,11im1 l!Q Box J8!J H111lmvrtll, Tr!)i,1S 7748.J U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Unit 1 January 22, 2018 NOC-AE-18003546 10 CFR 50.73 Docket No. STN 50-498 Licensee Event Report 2017-002-00 Unit 1 Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil Pursuant to 10 CFR 50.73(a)(2)(i)(B), STP Nuclear Operating Company hereby submits the attached South Texas Project Unit 1 Licensee Event Report 2017-002-00 for a condition prohibited by the plant Technical Specifications.

The event did not have an adverse effect on the health and safety of the public.

There are no commitments in this submittal.

If there are any questions, please contact Mr. Drew Richards at 361-972-7666 or me at 361-972-7344.

amr/JC ames Connolly Site Vice President Attachment: Unit 1 LER 2017-002-00, Unit 1 Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil STl34591589

NOC-AE-18003546 Page 2 of 2 cc:

(paper copy)

(electronic copy)

Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511 Lisa M. Regner Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (O8H04) 11555 Rockville Pike Rockville, MD 20852 NRC Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 Morgan, Lewis & Bockius LLP Paul Bessette U.S. Nuclear Regulatory Commission Lisa M. Regner NRG South Texas LP Mark Walker Jim von Suskil Skip Zahn CPS Energy Kevin Pollo Cris Eugster L. D. Blaylock City of Austin Elaina Ball John Wester Texas Dept. of State Health Services Helen Watkins Robert Free

NOC-AE-18003546 Attachment Unit 1 LER 2017-002-00 Unit 1 Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0313112020 (04-2017)

Estimaled,

httg:I /www. nrc.govlreading-rmldoc-collectionslnuregslstaff lsr1 022/r3D the NRC may not conduct or sponsor, and a person Is not required to respond lo, the information collection.

1. FACILITY NAME

12. DOCKET NUMBER

.PAGE South Texas Unit 1 05000498 1 OF5

4. TITLE Unit 1 Condition Prohibited by Technical Specifications Due to Inoperable Control Room Envelope Makeup Filtration System Heating Coil

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED SEQUENTIAL FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR REV MONTH DAY YEAR N/A NUMBER NO.

05000 11 23 2017 17

- 002

- 0 1

22 2018 FACILITY NAME DOCKET NUMBER N/A 05000

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: Check all that apply) 1 D 20.2201(b)

D 20.2203(a)(3)(i) 0 50.73(a)(2)(ii)(A)

D 50.73(a)(2)(viii)(A)

D 20.2201 (d)

D 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(B)

D 50.73(a)(2)(viii)(B)

D 20.22os(a)(1)

D 20.2203(a)(4)

D so.73(a)(2)(iii)

D 50.73(a)(2)(ix)(A)

D 20.2203(a)(2)(i)

D 50.36(c)(1)(i)(A)

D 50.73(a)(2)(iv)(A)

D 50.73(a)(2)(x)

10. POWER LEVEL D 20.2203(a)(2)(ii) 0 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 so.36(c)(2)

D 50.73(a)(2)(v)(B)

D 73.71(a)(5) 100 D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

D 50.73(a)(2)(v)(C)

D 73.77(a)(1)

D 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A)

D 50.73(a)(2)(v)(D)

D 73.77(a)(2)(i)

D 20.2203(a)(2)(vi)

I8] 50.73(a)(2)(i)(B)

D so.73(a)(2)(vii)

D 73.77(a)(2)(ii)

D 50.73(a)(2)(i)(C) 00THER Specify in Abstract below or in =

I. Description of Reportable Event A

Reportable event classification

This event is reportable under §50.73(a)(2)(i)(B) as an operation or condition prohibited by the plant's Technical Specifications.

B.

Plant operating conditions prior to event

Prior to the event on November 23, 2017, South Texas Unit 1 was operating in Mode 1 at 100 percent power.

C. Status of structures, systems, and components that were inoperable at the start of the event and that contributed to the event Unbeknownst to the Control Room operators at the start of the event, the Train "C" Control Room Makeup and Cleanup Filtration System was inoperable due to a misconfigured jumper on the circuit board associated with the Train "C" control room makeup filtration unit outlet low flow switch. The switch provides an input to energize/de-energize the associated filtration unit heater.

D. Narrative summary of the event

NOTE: When known, approximate times for all major occurrences are provided below.

March 2. 2017 STP Nuclear Operating Company (STPNOC) issued a purchase order to Fluid Components International (FCI) for four circuit boards. The circuit boards are configured with a set of jumper pins that can be configured in either position J12 or J13. In the purchase order, the specified circuit board model indicated that all four circuit boards were to be procured with a standard option of "ENERGIZED AT FLOW OR WET", which corresponds to the J 12 jumper position. The J13 position corresponds to the option of "ENERGIZED AT NO FLOW OR DRY."

April 1. 2017 STPNOC received the four circuit boards from FCI (Serial Numbers 624755, 624756, 624757, 624758).

May30. 2017 The circuit board with serial number 624756 was installed in Unit 1 Train "B" Fuel Handling Building (FHB) exhaust.

June 1. 2017

- 0 A scheduled monthly surveillance on Unit 1 Train "B" FHB exhaust was performed. During the surveillance, the associated FHB exhaust heater function was tested by measuring heater coil current. Based on the successful completion of this surveillance, the jumper on the circuit board with serial number 624756 was configured in the correct J12 position. Note that the FHB exhaust air system is not governed by Technical Specifications but is required in the Technical Requirement Manual during the movement of fuel within the spent fuel pool or when conducting crane operation with loads over the spent fuel pool. Page 2 of 5 (04-2017)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 3/31/2020

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LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/readinq-rm/doc-colleclions/nureqs/staff/sr1022/r3D

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

South Texas Unit 1 05000-498 September 7. 2017 YEAR 17

3. LER NUMBER SEQUENTIAL NUMBER

- 002 At 1036 hours0.012 days <br />0.288 hours <br />0.00171 weeks <br />3.94198e-4 months <br />, the quarterly surveillance was completed satisfactorily for Unit 1 Train "C" Control Room Makeup and Cleanup Filtration System.

September 27. 2017 The circuit board with serial number 624757 was installed in the Unit 1 Train "C" control room makeup filtration untt. Installation of the new circuit board was due to a planned periodic replacement and not because of a component failure. Following installation of the new circuit board, a post-maintenance test was performed to verify circuit board setpoints. However, a post-maintenance test to verify heater operability was not performed.

The as-found configuration of the removed circutt board was configured with the jumper in the J 12 position (correct position); the new circuit board was installed with the jumper in the J13 position (incorrect position).

At 1445 hours0.0167 days <br />0.401 hours <br />0.00239 weeks <br />5.498225e-4 months <br />, Unit 1 Train "C" Control Room Makeup and Cleanup Filtration System was declared Operable following planned maintenance.

November 23, 2017 At 0940 hours0.0109 days <br />0.261 hours <br />0.00155 weeks <br />3.5767e-4 months <br />, the scheduled quarterly surveillance on Unit 1 Train "C" Control Room Makeup and Cleanup Filtration System was commenced (Unit 1 was in Mode 1at100% power).

At 1544 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.87492e-4 months <br />, a manual actuation of the Untt 1 Train "C" control room emergency ventilation system was initiated per surveillance procedure.

At 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />, Unit 1 Train "C" Control Room Makeup and Cleanup Filtration System associated heater de-energized. The train was declared inoperable and Technical Specification 3.7.7 Action a was entered:

a. Wtth one Control Room Makeup and Cleanup Filtration System inoperable for reasons other than condition b or condition e, within 7 days restore the inoperable system to OPERABLE status, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

November 24, 2017 At 1202 hours0.0139 days <br />0.334 hours <br />0.00199 weeks <br />4.57361e-4 months <br />, after corrective maintenance was performed, the quarterly surveillance on Unit 1 Train "C" Control Room Makeup and Cleanup Filtration System was re-performed. The jumper configuration for the installed circuit board with serial number 624757 was corrected in the field and the circuit board was returned to service.

At 2305 hours0.0267 days <br />0.64 hours <br />0.00381 weeks <br />8.770525e-4 months <br />, following successful surveillance test performance, Unit 1 Train "C" Control Room Makeup and Cleanup Filtration System declared Operable.

Time unknown: The circuit board with serial number 624758, which was never installed in the plant, was verified to have the jumper in the correct J12 position.

December 14, 2017 The circuit board with serial number 624755 was inspected and the jumper was found to be misconfigured (i.e.,

jumper was in the J13 position). The circutt board was located in the warehouse and had never been installed in the plant. A "discrepant hold" was placed on the circuit board with serial number 624755 to ensure that the card is not installed in the plant until the jumper is properly configured.

REV NO.

- 0 Page 3 of 5 (04-2017)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 3/31/2020

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~'!H**/or LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/readinq-rm/doc-collections/nuregs/staff/sr1022/r3D

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

South Texas Unit 1 05000-498

C. Safety consequences and implications

YEAR 17

3. LER NUMBER SEQUENTIAL NUMBER

- 002 When STPNOC reanalyzed the UFSAR Chapter 15 Accident Analyses for Alternate Source Term, Control Room makeup filtration was not credited in any accident analyses. Only recirculation filtration was credited in the design bases calculations. Therefore, reduced makeup filtration effectiveness, due to loss of heater function in a makeup train heater, would have no effect on the plant design basis assumptions.

Control Room makeup filtration is only credited for use as a compensatory action if tracer gas testing fails the inleakage measurement limtt. The presence of uncredited makeup filtration would provide margin until the measured inleakage problem is resolved. During the time period of this event, no tracer gas testing was performed in Unit 1, so makeup filtration was not credited as a compensatory measure while the Train "C" Control Room Makeup and Cleanup Filtration System was inoperable.

In the STP PRA model, the system function of the Control Room Makeup and Cleanup Filtration System is to provide outside air for cooling of plant equipment located in the Control Room Envelope. The heaters in the makeup filtration portion of the system are not modeled in the STP PRA model and have no impact on core damage frequency or large early release frequency. The heaters would become important after a core damage event followed by a radiological release to provide clean air to the Control Room Envelope for habitability; however, this is beyond the scope of the STP PRA model, which is a Levels I and II PRA model.

From a Technical Specification perspective, during the time period of this event, the other two trains of the Control Room Makeup and Cleanup Filtration System were Operable and capable of performing their required functions. Note that the Control Room Makeup and Cleanup Filtration System trains are 50% capacity trains (i.e.,

two trains are required to meet the design bases function).

IV. Cause of the event

The cause of the event is the applicable maintenance work instructions did not include steps to: (1) ensure that the circuit board jumper is in the correct position, and (2) conduct a post-maintenance test to ensure proper operation of the heaters.

V. Corrective actions

The applicable maintenance work instructions will be revised to (1) ensure that the circuit board jumper is in the correct position, and (2) conduct a post-maintenance test to ensure proper operation of the heaters.

VI. Previous similar events

An operating experience review was conducted to find similar events regarding improperly configured jumpers. One event in the past ten years was discovered (reference STP Condition Report 09-16821). This event did not result in an LER because the incorrectly installed jumper was discovered prior to the component being placed into service. No changes to written instructions were made as a result of this event.

REV NO.

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