L-2021-070, Commitment Revision Summary Report for Excess Letdown Thermal Relief Valve
| ML21179C283 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 06/24/2021 |
| From: | Hess R Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-2021-070 | |
| Download: ML21179C283 (2) | |
Text
Florida Power & Light Company 9760 SW 344 St Homestead, FL 33035 U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, D.C. 20555-0001 Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Commitment Revision Summary Report for Excess Letdown Thermal Relief Valve
References:
- 1. FPL Letter L-97-021, Dated January 28, 1997, NRC Generic Letter 96-06 (response)
- 2. FPL Letter L-99-117, Dated January 4, 1999, NRC Generic Letter 96-06 (response to RAIs)
- 3. NEI Guidance 99-04, NEI 99-04, Guidelines for Managing NRC Commitments
- 4. Turkey Point Condition Report (AR) 02370941 The purpose of this letter is to provide a commitment revision summary report for replacing the previously installed thermal relief valves in the excess letdown piping. The commitment revision review was performed in accordance with guidance provided in NEI 99-04, Guidelines for Managing NRC Commitments (Reference 3). The justification for changing the commitment is documented in the Turkey Point Corrective Action Program (Reference 4) and discussed herein.
Existing Commitment
Description:
Installation of thermal relief valves in the excess letdown piping sections between CV-3-387 and HCV-3-137 in Unit 3, and CV-4-387 and HCV-4-137 in Unit 4.
Revised Commitment
Description:
Bypass lines with a check valve are installed around CV-3-387 and CV-4-387 for Turkey Point Units 3 and 4 respectively, replacing the previously installed thermal relief valves in the excess letdown piping sections between CV-3/4-387 and HCV-3/4-137 to provide relief from any thermal expansion of fluid which could lead to over pressurization addressing the concerns of GL 96-06.
Justification:
The original commitment was made in response to Generic Letter 96-06, Turkey Point in References 1 and 2 and. FPL letter L-99-117, Table 1, Item 6, documents how the installation of thermal relief valves in the Excess letdown piping, between CV-*-387 and HCV-*-137, addresses the concerns of thermal expansion of fluid that could lead to piping overpressurization. This commitment was explicitly stated in the NRCs Evaluation report for the resolution of GL 96-06 issues for Turkey Point Units 3 and 4, dated August 12, 1999.
June 24, 2021 L-2021-070
L-2021-070 The Excess letdown thermal relief valves RV-3/4-304 have had a history of sticking open, during certain transients, resulting in identified leakage, which in Unit 4 drains to the PRT, and in unidentified leakage, which in Unit 3 drains to Containment Sump. These relief valves have been considered as an additional burden to operation of the Turkey Point units.
The revised commitment to install a bypass line around CV-3/4-387 with a check valve to relieve excessive pressure conditions in order to replace the thermal relief valves offers an equivalent method to the thermal relief valves to continue to prevent piping overpressurization due to thermal expansion of fluid in the susceptible Excess Letdown piping. The revised commitment to replace the thermal relief valves with a modification which offers the same piping protections does not change the conclusion on the resolution of the GL 96-06 issues for Turkey Point Units 3 and 4.
Turkey Point Unit 4 modification was completed on May 28, 2005, PC/M 05-004 Turkey Point Unit 3 modification is documented in Engineering Change EC 294126 is planned for the next refueling outage in October of 2021.
If you have any questions or require additional information, please contact Mr. Robert Hess, Licensing Manager, at (305) 246-4112.
ess Licensin Manager Turkey Point Nuclear Plant cc:
USNRC Regional Administrator, Region II USNRC Project Manager, Turkey Point Nuclear Plant USNRC Senior Resident Inspector, Turkey Point Nuclear Plant 2