ML20280A481
| ML20280A481 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/06/2020 |
| From: | Office of Nuclear Reactor Regulation |
| To: | NRC/NRR/DNRL |
| References | |
| Download: ML20280A481 (7) | |
Text
From:
Schiller, Alina Sent:
Tuesday, October 6, 2020 8:39 AM To:
Vogtle PEmails Cc:
Scarbrough, Thomas
Subject:
ITAAC 216 PXS Check Valve Testing - presentation material for 10/8/20 Vogtle Units 3 and 4 public meeting Attachments:
ITAAC 216 Public call 10-8 Final.docx From: Petrak, Tom G. <TGPETRAK@southernco.com>
Sent: Tuesday, October 06, 2020 8:02 AM To: Schiller, Alina <Alina.Schiller@nrc.gov>; Arafeh, Yasmeen N. <YNARAFEH@southernco.com>
Cc: Welch, Christopher <Christopher.Welch@nrc.gov>; Gaslevic, James <James.Gaslevic@nrc.gov>
Subject:
[External_Sender] ITAAC 216 PXS Check Valve Testing
- Alina, Attached is the presentation material for the first topic for this Thursdays public call. I will be sending the presentation for the other topic later this morning.
Thomas G. Petrak Vogtle 3&4 ITAAC Manager Southern Nuclear Operating Company 7835 River Road, Bldg. 302 - Waynesboro, GA 30830 (706) 848-1575(o)
(706) 833-7581 (c)
Hearing Identifier:
Vogtle_COL_Docs_Public Email Number:
593 Mail Envelope Properties (SJ0PR09MB660522FF175AE44A2F9728C5960D0)
Subject:
ITAAC 216 PXS Check Valve Testing - presentation material for 10/8/20 Vogtle Units 3 and 4 public meeting Sent Date:
10/6/2020 8:38:51 AM Received Date:
10/6/2020 8:38:54 AM From:
Schiller, Alina Created By:
Alina.Schiller@nrc.gov Recipients:
"Scarbrough, Thomas" <Thomas.Scarbrough@nrc.gov>
Tracking Status: None "Vogtle PEmails" <Vogtle.PEmails@nrc.gov>
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SJ0PR09MB6605.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 724 10/6/2020 8:38:54 AM image001.png 3937 ITAAC 216 Public call 10-8 Final.docx 844083 Options Priority:
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PXS Check Valve Testing Status Table 2.2.3-1 (cont.)
Equipment Name Tag No.
ASME Code Section III Seismic Cat. I Remotely Operated Valve Class 1E/
Qual.
Harsh Envir.
Safety-Related Display Control PMS/
DAS Active Function Loss of Motive Power Position IRWST Injection A Check valve PXS-PL-V122A Yes Yes No
- / -
No
- / -
Transfer Open/
Transfer Closed IRWST Injection B Check Valve PXS-PL-V122B Yes Yes No
- / -
No
- / -
Transfer Open/
Transfer Closed IRWST Injection A Check Valve PXS-PL-V124A Yes Yes No
- / -
No
- / -
Transfer Open/
Transfer Closed IRWST Injection B Check Valve PXS-PL-V124B Yes Yes No
- / -
No
- / -
Transfer Open/
Transfer Closed
UIN Methodology The PXS check valves V122A/B and V124A/B have position indication Venturis are installed in place of the IRWST Injection Line Squib Valves to create a flowpath.
Venturis also act as a flow measurement element and have identical flow characteristics of an open squib valve.
IRWST water level is raised 8 to 15.
Valve position is verified closed per check valve position indication MOV opened and check valves verified to partially open by measured flow thru venturis Check valve position indication is checked to verify check valve partially open (not part of acceptance criteria for check valve opening)
MOV is closed and check valve is verified to close by verifying the position indication went from partially open to closed.
Note: A flowrate of greater than 600 gpm is needed to open the check valve sufficiently to have the position indication show that the valve is partially open.
Test Results To date, there have been three tests performed for the IRWST Injection Line Check Valves 3-PXS-PL-V122A/B and 3-PXS-PL-V124A/B.
First Test All check valves opened properly as indicated by flow measured through venturis but the position indicators didnt operate as expected.
After the first test, all check valves were disassembled and inspected.
o These inspections verified the check valve could open and close properly by raising and lowering each check valve disc.
o Freedom of movement was verified and the valves were inspected to ensure they all seated properly on the closed seat.
All check valve position indicators were aligned to give indications in the full open, full closed, and intermediate positions.
Second Test All check valves opened properly as indicated by flow measured through venturis.
Check valves SV3-PXS-PL-V122A, -V124A and -V124B opened partially as expected and closed using the position indication.
Check valve position indication for SV3-PXS-PL-V122B didnt change position.
o After the second test, SV3-PXS-PL-V122B position switches were adjusted again.
Third Test Check valves SV3-PXS-PL-V122A, -V124A and -V124B opened partially as expected as shown by position indication.
Check valves SV3-PXS-PL-V122A and -V124B returned to the closed position immediately following the test.
Check valve SV3-PXS-PL-V124A didnt immediately go to the closed position but did ultimately go to the closed position.
Check valve SV3-PXS-PL-V122B didnt change position. From research that was performed on Sanmen and Haiyang lessons learned, a similar situation occurred at both plants due to the low flow that is passed through this check valve (approximately 450 gpm). NOTE: Next lowest flow is through SV3-PXS-PL-V124A at approximately 650 gpm.
Methodology Enhancement Use internal inspection of the check valves to enhance the verification of check valve closure.
o Remove check valve bonnet o Verify that the check valve open/closes smoothly and seats properly.
o Verify that the check valve closes with gravity with no assistance required.
o Adjust check valve position limit switches if needed.
o Restore check valve bonnet.