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Vc Summer - Unit 1
Event date: 10-31-2017
Report date: 12-15-2017
Reporting criterion: 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3952017006R00 - NRC Website
LER 17-006-00 for Virgil C. Summer, Unit 1, Regarding Technical Specification Action not Met for Inoperable Oxygen Monitor
Person / Time
Site: Summer, Vc Summer - Unit 1 South Carolina Electric & Gas Company icon.png
Issue date: 12/15/2017
From: Lippard G A
South Carolina Electric & Gas Co
Document Control Desk, Office of Nuclear Reactor Regulation
RC-17-0170 LER 17-006-00
Download: ML17349A660 (4)

Es mare burden per Tsponse to comb4 vvitn th:s mandatory collectbn reques:: 53 hours6.134259e-4 days <br />0.0147 hours <br />8.763227e-5 weeks <br />2.01665e-5 months <br />. Reported essons 'eamed are ;ncorporated into tie licensrg process and fed bank to il,CJSZy. Ser.c comments regardng burden estimate to the .nfo.rmat:or Serv:ces Branch (7-2 143). U.S. Nuo:ear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nro.gov, and to the Desk Officer: Of ice of Information and Regulatory Affairs, NEOB-10202. (3150-0104), Office of Management and Budget. Washington, DC 20503. If a means used to impose en information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

05000- VC Summer - Unit 1 395 1.0 EVENT DESCRIPTION At 0230 on October 30, 2017, VCSNS Unit 1 entered Technical Specification (TS), Explosive Gas Monitoring Instrumentation, Action b. Entry into the TS action was a result of having one less than the minimum number of operable oxygen monitoring channels on the Waste Gas Holdup System Explosive Gas Monitoring System. In order to maintain the system in operation, grab samples were required once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The Control Room entered station procedure GTP-702. General Test Procedure for Surveillance Activity Tracking and Triggering, and briefed chemistry personnel on taking grab samples. However, inadequate communication during shift turnover allowed the time requirement for the sample. due at 0230 on October 31. 2017, to be exceeded. The deficiency was identified at approximately 0300. and a grab sample was performed at 0405 on October 31, 2017.

The results of the analyzed grab sample were satisfactory. The plant remained in normal operation at 100% power during this event.

2.0 EVENT ANALYSIS A catalytic recombiner disposes of hydrogen brought into the Waste Gas System by adding a controlled amount of oxygen in the recombiner to react with the hydrogen as the gas flows through the catalyst bed. Water vapor formed by the reaction is then condensed and removed from the system. The control system is designed with careful consideration for the potential hazards involved in processing a gas mixture containing hydrogen and oxygen contaminated with radioactive fission gases.

There are two oxygen monitors provided, one each on the inlet and outlet of the recombiner. TS in conjunction with Table 3.3-13, Line Item la, requires that at least two channels are operable for oxygen monitoring in the Waste Gas Holdup System Explosive Gas Monitoring System instrumentation. TS Action b specifies that with less than the minimum number of channels available, take the action indicated by Table 3.3-13. Table 3.3-13 Line Item la and referenced notation (Action 44) allow the continued operation of the system, provided grab sampling be performed at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, when the number of operable channels is one less than the required minimum.

On October 30. 2017, the outlet oxygen monitor IAE01119A went out of service. Upon entry into the TS action statement.

the Control Room initiated station procedure GTP-702. The Control Room notified chemistry of the grab sample date and time requirements. The sampling time requirements were not adequately communicated to the oncoming night shift Chemistry personnel. As a result, the grab sample and analysis was not performed by 0230 on October 31, 2017.

At approximately 0300 on October 31, 2017 the Control Room contacted Chemistry to inquire about the sample results. It was determined that a sample had not yet been collected. Chemistry collected a sample at 0405 on October 31, 2017 and analysis determined it to be SAT (satisfactory).

As of November 29. 2017. VCSNS Unit 1 restored the affected instrumentation and has exited TS Action b.

Estimated burden pe: 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 :-:corporated into the licens:ng process and fed back to Industry. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nro.gov, and to the Desk Officer. Office of Information and Regulatory Affairs, used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information co::ection.

05000- VC Summer - Unit 1 395 [2017 006

  • 00 , 3.0 SAFETY SIGNIFICANCE The Waste Gas Holdup System oxygen monitors are not included in the PRA model.

There was no risk impact from this event. A grab sample was taken at 0405. Analysis determined oxygen levels were satisfactory.

4.0 PREVIOUS OCCURRENCE No previous occurrences identified within the last three years.

5.0 CORRECTIVE ACTIONS The Station's corrective actions are documented in the CR-17-05725 Quick Cause Evaluation.

The below two actions are being completed to reinforce station expectations of communications during shift turnovers and the time requirements for taking grab samples associated with the Waste Gas System.

1. Operations Management to discuss Missed Grab Sample with operations shifts during training department meetings.

2. Chemistry to discuss missed Grab Sample with shift chemists.