Term
HWC
Describe the HWC trips and setpoints. |
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Definition
-Main steam flow: <30%.
-11 or 12 AE trip: AO-1085A/B closed.
-Total H2 flow high: >58scfm.
-Either RFP H2 flow high: >24scfm.
-Low O2 pressure: <45psig.
-Area H2 monitors: >1% H2.
-O2 concentration at recombiner outlet: <5%.
-Both recombiner outlet valves closed: AO-7557A/B shut.
-Manual trip from control room or local at C-308. |
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Term
HWC
Describe the HWC and RFP interlock. |
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Definition
| -If RFP secured or its recirc valve is open then that trains supply valve (CV-4152A/B) will shut. |
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Term
HWC
Describe the gas compressor start signals. |
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Definition
-H2 tank pressure at 110psig with the pump not operating and H2 receiver <2000psig.
-H2 receiver <1800psig, with pump not running, and tank pressure >80psig. |
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Term
HWC
Describe when the H2 pump starts. |
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Definition
| Cycles between 1200 to 1900 psig. |
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Term
HWC
Describe the pump trips. |
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Definition
-High receiver pressure (1900#).
-Pipe line low temp: -250F.
-Relief valve open: Tailpipe at -40F.
-Low N2 purge or system pressure. |
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Term
HWC
Describe O2 supply on loss of normal supply. |
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Definition
-O2 bottles available.
-That will ensure enough O2 available for complete H2 recombination of H2 remaining in system after trip. |
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Term
HWC
Describe what happens on system trip. |
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Definition
-Pretty much all valves close.
-O2 supply flow to recombiners (primary and backup) take 12 minutes to close to ensure enough to recombine the H2.
-All others close immediately. |
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Term
HWC
Describe the O2 tank high pressure relief. |
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Definition
-250psig.
-Vented to atmosphere. |
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Term
HWC
Describe any time delays in HWC. |
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Definition
-Injection of O2 is delayed based on Rx power.
-At 100% roughly 45 seconds to allow time for the H2 to show up at the O2 injection point. |
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Term
HWC
Describe the steam flow interlock. |
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Definition
| H2 is interlocked to prevent injection when steam flow is <30%. |
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Term
HWC
Describe rad levels and protection with HWC. |
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Definition
-Rad levels in steam areas can increase by 3 to 5 times with an increase in H2 injection rate.
-Can reduce HWC injection for work if will save 1 rem and have shift supervision permission.
-Unplanned lowering takes Plant Manager permission. |
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Term
HWC
Describe RWCU relationship with HWC. |
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Definition
| -Maximize RWCU flow 24 hours prior to HWC injection reduction and maintain until 72 hours after HWC restored to normal injection rate. |
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