ML112420155

Draft Request for Additional Information License Amendment Request to Revise Technical Specification Limiting Condition for Operation 3.7.4 Atmospheric Dump Valves

ML112420155
Person / Time
Site:	Palo Verde
Issue date:	08/26/2011
From:	Lauren Gibson Plant Licensing Branch IV
To:	Stroud R Arizona Public Service Co
Gibson, Lauren, NRR/DORL/LPL4, 415-1056
Shared Package
ML112420145	List: ML112420147 ML112420155
References
TAC ME6566, TAC ME6567, TAC ME6568
Download: ML112420155 (1)

Text

DRAFT REQUEST FOR ADDITIONAL INFORMATION PALO VERDE NUCLEAR GENERATING STATION LICENSE AMENDMENT REQUEST CONCERNING TS 3.7.4 ATMOSPHERIC DUMP VALVES TAC NOS. ME6566. ME6567, ME6568 By letter dated June 22, 2011, Arizona Public Service Company, the licensee for Palo Verde Nuclear Generating Station Units 1, 2, and 3, requested a license amendment that would revise Technical Specification (TS) Limiting Condition for Operation (LCO) 3.7.4, Atmospheric Dump Valves.

In order to complete the review, the staff requests the following additional information.

1. Please provide the technical basis, including a discussion of defense in depth and safety margins, for

a. Proposed LCO 3.7.4, Condition A, Completion Time of 7 days

b. Proposed LCO 3.7.4, Condition B, Completion Time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

2. Regarding the design basis events for which ADVs are required and which require the consideration of loss of offsite power, please explain how the main steam condenser provides defense-in-depth to the ADV safety and design functions.

3. Discuss the impact that manual ADV operation, or maintaining steam generator pressure with main steam safety valves, would have on safety margin for design basis events, including but not necessarily limited to:

a. Postulated loss of coolant accidents

b. Natural circulation cooldown as described in Generic Letter 81-21

c. Steam generator tube rupture events

d. Main steam and feedwater line breaks