ENS 52484
ENS Event | |
|---|---|
21:00 Jan 11, 2017 | |
| Title | Teflon Found in Containment Spray Pump Components |
| Event Description | On September 16, 2016, Comanche Peak reported an unanalyzed condition and potential loss of safety function per 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(v) related to Teflon (PTFE) installed in the pressure gauge diaphragm seal assemblies for all four of the Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2 (EN#52244). On November 14, 2016, this event was subsequently retracted.
On December 12, 2016, during the ongoing extent of condition review, Teflon was also found to be installed in the suction and discharge pressure gauge diaphragm seal assemblies for the Unit 1 and 2 Containment Spray Pumps. On January 11, 2017 at approximately 1500 CDT, the reportability evaluation determined that reasonable assurance did not exist that the Containment Spray system would have been able to fulfill its design function of removing heat from the containment environment without impacting the applicable dose limits. Teflon (PTFE) is a restricted material normally prohibited from use in contact with reactor coolant or in radiation environments. Teflon (PTFE) is not radiation tolerant and degrades in a radiation environment. The Teflon (PTFE) used in these diaphragm seal assemblies could fail during a postulated Loss of Coolant Accident (LOCA) which could cause the Containment Spray Pumps on Units 1 and 2 to be inoperable, and exceed system leakage limits. This could challenge dose limits and in plant post-accident accessibility. This represents an unanalyzed condition. The pressure gauges and diaphragm seals for all of the Unit 1 and 2 Containment Spray Pumps have been isolated and the Unit 1 and 2 Containment Spray Pumps are operable. The Teflon (PTFE) has likely existed in these diaphragm seals since initial plant licensing. Luminant Power is continuing to investigate the extent of this condition and potential repair techniques. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Comanche Peak  Texas (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+-4.07 h-0.17 days <br />-0.0242 weeks <br />-0.00558 months <br />) | |
| Opened: | Hunter Schill 16:56 Jan 11, 2017 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Jan 11, 2017 |
| 52484 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 528172017-06-21T15:00:00021 June 2017 15:00:00
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