ML18250A322
| ML18250A322 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 09/06/2018 |
| From: | Audrey Klett Plant Licensing Branch II |
| To: | Wasik C Duke Energy Carolinas |
| References | |
| L-2017-LLA-0365 | |
| Download: ML18250A322 (3) | |
Text
1 NRR-DMPSPEm Resource From:
Klett, Audrey Sent:
Thursday, September 6, 2018 1:07 PM To:
Wasik, Christopher J Cc:
Shingleton, Boyd
Subject:
NRC Request for Additional Information for Oconee LAR 2017-03 (L-2017-LLA-0365)
Hi Chris, By letter ONS-2017-074 dated October 20, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17299A114), Duke Energy Carolinas, LLC (the licensee) applied for license amendments to Renewed Facility Operating Licenses DPR-38, DPR-47, and DPR 55, for the Oconee Nuclear Station, Units 1, 2, and 3 (Oconee), respectively. By email dated May 1, 2018 (ML18122A374), the NRC staff requested additional information. By letter dated June 15, 2018, as superseded by letter dated July 20, 2018 (ML18214A364), the licensee responded to the request. In order to complete its review, the staff developed the request for additional information (RAI) below based on the licensees response dated July 20, 2018. The RAI is numbered sequentially from the APHB RAIs dated May 1, 2018. Per an email dated August 27, 2018, from Mr. Boyd Shingleton of the licensees staff, the NRC staff requests the licensee to respond to the RAI in this email on or by October 5, 2018.
RAI-7 (APHB)
The Enclosure of the licensees amendment request dated October 20, 2017, describes operator manual control of a newly installed standby shutdown facility (SSF) letdown throttle valve. Section 2.1.2.2 of the Enclosure describes that current plant operational practice is to maintain the existing SSF letdown throttle valve open and flow through the SSF letdown line is set by an orifice in the piping. Therefore, flow through the line cannot be throttled.
Per the licensees supplement dated July 20, 2018, the SSF was originally licensed with a letdown line that had a throttling capability. Therefore, the licensee does not consider operator manual control to throttle the new SSF letdown line as a new operator action. The licensees supplement dated July 20, 2018, states the following in response to RAI-3.B:
The SSF letdown control valve was designed as, and originally functioned as, a throttle valve, but due to subsequently identified design limitations the valve is now only cycled completely open and closed.
In addition, the response to RAI-6.A of the supplement dated July 20, 2018, states the following:
No additional operator actions requiring NRC review and approval have been identified. The SSF was originally licensed with a letdown line that had throttling capability. Throttling of the SSF letdown line was previously reviewed and approved (Reference NRC Safety Evaluation for the SSF dated April 28, 1983, Accession Number 8305200103). Manual throttling of the new SSF letdown line is not a new operator action.
The NRC staff reviewed the referenced NRC safety evaluation (SE) dated April 28, 1983 (ADAMS Accession No. ML103370444) and did not find information supporting the statement in the subject SE indicating Oconee was originally licensed to throttle SSF letdown line flow. Section 2.1 of the NRC SE states:
The letdown valve is powered from the SSF power system and is controlled from the SSF control room.
2 This statement does not define control of the valve as throttling valve position as opposed to controlling the valve open and closed. Review of Section 9.6, Standby Shutdown Facility, of the Oconee UFSAR also did not identify any information regarding throttling the SSF letdown line flow.
RAI-7.A The staff requests the licensee to provide the specific location of the docketed information that supports the licensees response to RAI-6.A that the SSF was originally licensed with a letdown line that had throttling capability and that throttling of the SSF letdown line was previously reviewed and approved by the NRC staff.
RAI-7.B:
If documentation cannot be provided to support a response to RAI-7.A above, then the staff requests the licensee to:
(1) Provide the basis and justification regarding the feasibility and reliability for the operator action to manually throttle the SSF letdown line valve for all conditions (nominal and off-nominal) as described in the proposed LAR dated October 20, 2017.
(2) Provide the validation performed regarding the operator action to manually throttle the SSF letdown line valve for all conditions (nominal and off-nominal) as described in the proposed LAR dated October 20, 2017.
(3) Describe any staffing changes required to implement the operator action to manually throttle the SSF letdown line valve for all conditions (nominal and off-nominal) as described in the proposed LAR dated October 20, 2017.
(4) Provide a description of the potential impacts on the reactor/plant should the operator fail to correctly manually throttle the SSF letdown line valve for all conditions (nominal and off-nominal) as described in the proposed LAR dated October 20, 2017.
(5) Describe any relevant operating experience related to controlling SSF letdown line flow by manually throttling the SSF letdown line as opposed to maintaining the letdown line valve full open or full closed for all conditions (nominal and off-nominal) as described in the proposed LAR dated October 20, 2017.
Audrey Klett Project Manager NRR/DORL/LPLII-1 301-415-0489
Hearing Identifier:
NRR_DMPS Email Number:
554 Mail Envelope Properties (Audrey.Klett@nrc.gov20180906130600)
Subject:
NRC Request for Additional Information for Oconee LAR 2017-03 (L-2017-LLA-0365)
Sent Date:
9/6/2018 1:06:34 PM Received Date:
9/6/2018 1:06:00 PM From:
Klett, Audrey Created By:
Audrey.Klett@nrc.gov Recipients:
"Shingleton, Boyd" <Boyd.Shingleton@duke-energy.com>
Tracking Status: None "Wasik, Christopher J" <Christopher.Wasik@duke-energy.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 5101 9/6/2018 1:06:00 PM Options Priority:
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