ML100670220

GL2008-01 Void Invasion Modification Part 2

ML100670220
Person / Time
Site:	Diablo Canyon
Issue date:	03/08/2010
From:	Nuclear Energy Institute
To:	Office of Nuclear Reactor Regulation
Lyon W, DSSA/SRXB, 415-2897
References
Download: ML100670220 (11)

Text

2. Discharge Piping - Enhance Isolation From Accumulators & Replace Check Valves A. Replace 10 AOVs in the test line on the accumulator side with Anchor Darling Manual Valves B. Replace all 4 SI Check Valves C. Replace another 9 AOVs, and install 37 Manual Isolation Valves for Test Optimization Modifications and To Add Barriers to Enhancement Isolation (6 isolation valves in between Accumulator and ECCS Lines in most cases)

Test Station

2- A: AOV Replacement - before (e.g., Accumulator Side AOV Replacement)

AOVs

2- A: AOV Replacement - after (e.g., Accumulator Side AOV Replacement)

AOV (Acc. Side)

Replacement

Old 8877C & 8879C New - 4 each manual valves with drain add

2-B: Increase Leakage Barriers (e.g., ECCS Test Header Modification)

Test Station #2

3. Dynamic Flushing (Fr > 2.0) z ECCS Injection Lines High Points Are Drained During Mid-Loop z Most Voids Are Filled by Vacuum Refill, But Some Voids Are Trapped Upstream of Check Valves Fr > 2 z RHR Discharge Lines: Fr > 2.0 z CCP & SIP Injection Lines: Fr > 6.0 z RHR Heat Exchanger: Fr > 6.0

Cal Poly Senior Project

- Void Recirculation Loop z Passive - Uses Eductive Force z Reduces Void Fraction to the Pump

Cal Poly Senior Project - Void Recirculation Loop Cal Poly Senior Project - Void Recirulation Loop