ML16294A111

Email Attachment McGuire Nuclear Station, Unit 2 - Acceptance Review - Relief Request Alternative Testing Approval for Two PORV Block Valves

ML16294A111
Person / Time
Site:	Mcguire, McGuire
Issue date:	10/18/2016
From:	Vu P Duke Energy Carolinas
To:	Robertson J, V Sreenivas Duke Energy Carolinas, Plant Licensing Branch II
Sreenivas V, NRR/DORL/LPL2-1, 415-2597
References
CAC MF8416
Download: ML16294A111 (1)

Text

QUESTIONS:

1. Does the Surveillance Test Frequency Program allow the test frequency to be extended beyond 2X the existing frequency?

2. The Relief Request indicates we will test the valve at cold shutdown. Is the cold shutdown test adequate to test the valve function at the applicable TS modes?

ANSWERS:

1. PORV Block Valve quarterly cycling is required by both the McGuire IST program and TS SR 3.4.11.1. McGuire received approval to relocate specific SR frequencies to a licensee controlled program per TSTF-425 Rev. 3 on March 29, 2011. The program is referred to as the Surveillance Frequency Control Program (SFCP) which is in accordance with NEI 04-10 Rev. 1. The SFCP provides a risk informed and deterministic process to change frequencies without prior NRC approval.

Step 6 of NEI 04-10 provides guidance for changing frequencies:

In general, the next logical surveillance test interval (STI) given in technical specifications is chosen for improvement. For example, an STI of one month would be changed to quarterly, quarterly to semi-annual, semi-annual to annual, etc. If a STI was chosen which goes beyond the next logical interval, a phased implementation would probably be more appropriate.

The above guidance does not preclude a frequency change beyond the next logical interval.

The Duke Energy Fleet procedure for the SFCP, AD-EG-ALL-1216, Step 5.3, states:

In general, the next logical interval given in SF List is chosen as the proposed change (e.g.,

31 days would be changed to 92 days, 92 days to 184 days, 184 days to 12 months). If a frequency is chosen beyond the next logical interval, then consider a phased implementation as part of the deterministic evaluation. For changes that go beyond the next logical interval without phased implementation, provide a basis.

2. The PORV block valves in question are motor driven with gear drive actuators. Based on this design, the VST will be consistent as long as the motor receives consistent electrical frequency. Past VST data show consistent valve stroke time in hot and cold system conditions. Based on this, the cold shutdown test is adequate to test the valve function at Commented [VPT1]: PORV Block Valve VST History.xlsx the applicable TS modes.