[HR] Radwaste HVAC Flashcards
[HR]
Functions? (3)
-maintain ventilation in process equipment areas
-personnel safety in access areas
-restrict spreading of airborne radioactivity
[HR]
Which location features recirculation of air?
How is fresh air and pressurization introduced to recirc location?
-RW Control Room
-Recirc Air mixes w/ RW AHU Supply Air
[HR]
What temp is RW CR maintained?
70 – 80F
[HR]
Why does the system maintain RW Bldg at a negative pressure?
Minimizes amount of uncontrolled/unmonitored release of potentially radioactivity air from RW to O/S atmosphere
[HR]
What 6 systems vent to [HR]?
[GR] Gaseous Radwaste (GR)
[LR] Liquid Radwaste (LR)
[SR] Solid Radwaste (SR)
[CH] Chemical and Volume Control (CH)
- VCT
[SS] Nuclear Sampling (SS)
[RD] Radioactive Waste (RD)
[HR] and [DS]?
[DS] Provides water to air washers (RW A/C)
[HR]
What provides cooling water to the RW CR ACU?
[WC] Normal Chilled Water System
[HR]
What [GR] components vent to the [HR]? (2)
[GR] Waste Gas Surge Tank relief
[GR] Compressor pre-filter, suction filter and package
System release path discharges upstream of the AFUs
[HR]
What components of the [LR] Liquid Radwaste system vent to the [HR] system? (5)
Evaporator,
surface condenser
and heater
Concentrate Monitor tanks
LR system Holdup Tanks
[HR]
What [CH] components vent to [HR]? (2)
- BAC condensate & ion exchanger
[HR] What component of [SS] Nuclear Sampling System vents to [HR]?
O2 Analyzer Exhaust
[HR]
What part of [RD] Radioactive Waste Drain System vents to HR system?
[RD] RW sump
[HR]
What system provides air to the HR air dampers?
What happens if air is lost?
[IA] Instrument air
If [IA] is lost, the dampers fail closed causing the AHUs / AFUs to trip on overload
[HR]
Which radiation monitor tracks the GR system release flowpath?
RU-12
Which radiation monitors keeps track of the plant vent?
RU-143 and 144
The discharge of the Radwaste Building HVAC system is monitored by what component? Where is thi component located?
RU-14, upstream of the AFUs
RW building roof
What HR exhaust does RU-15 monitor? Where is this monitor located?
Combined exhaust from the Waste Gas System area
140’
Where do the Radwaste Building HVAC normal AHUs drain/overflow to?
OW, Control Building West sump
Concerning the Radwaste Control Room Normal AHU, when would the Duct Heater energize?
Supply air temperature is low (<50F), if the heater airflow is not low and if the heater supply breaker is closed
Where are the Normal supply AHUs located?
Radwaste Building roof
[HR] Normal Supply AHUs
-how are fans and dampers interlocked?
Each damper interlocked w/ fan
(fan is running the damper is open)
(fan is stopped the damper is closed)
[HR]
Normal Supply AHU Duct heater energizes when?
RW exhaust air temperature <75F
and if the associated AHU fan is running
Where are the controls for the HR system located at?
Radwaste Control Panel in the Radwaste Control room on the 120’ level of the Radwaste Building
How many signals are required to start the air washer pumps and where do those signals come from?
Two signals
A permissive signal from the associated running AHU fan and a signal from the intake air temperature controller when the outside air is 80F or above
What is the purpose of the Exhaust Normal Air Filtration Units? What components are i them? Where do they exhaust to?
Two 50% capacity Exhaust units operating in parallel are provided to filter dust and particulate matter from the air exhausted from the Radwaste Building
contains high efficiency filters and HEPA filters
plant vent
Where is the Laundry and Decon Facility located?
Unit 1 only
Concerning the Decon and laundry facility Normal AFU and AHU, which one is placed in service first and why?
AFU
To avoid positively pressurizing the Decon facility
[HR] Components powered by NH?
RW Normal
- AHU fans
- AHU recirculation pumps (air washer pumps)
RW CR
-Normal AHU fan
-Fan Motor space heaters
-AHU heater
[HR] Components powered by NG?
Pre-Access Normal AFU fans
and normal supply duct heaters
Shutting down one AFU dictates the shutting down of one AHU and vice versa. For the shutdown, which one is secured first and why?
AHU shall be shutdown before the AFU to assure negative pressure is maintained in the Radwaste Building
If both AFUs and both AHUs are to be stopped, whose permission do you need?
Shift Manager/CRS
[HR] affected by loss of [IA]?
@ 30 psig :
1- RW Normal Air Handling Units damper fail closed and the fans will trip on thermal overload.
2-RW Normal Exhaust AFU isolation dampers fail closed at 30 psig and decreasing and the exhaust fans will trip on thermal overload. This will cause the flow control valves for GR system to go closed, stopping a GR release if one is in progress
3- RW Control Room AHU will lose its chilled water supply due to two valves going closed. The fans will keep running, recirculating ambient Control Room Air only.
What happens on a loss of NK? What if NKN-D42 is lost?
AHUs and AFUs dampers fail closed
causing
AHUs and AFU fans to trip on overload
(D42) Radwaste control room annunciator is lost
How does HR interface with NG?
powers RW normal duct heaters and normal AFU fans
How many HR supply AHUs are there? What is the capacity of each unit and how are they aligned? What components are in it?
two
50%
in parallel
louvers, dry media filter, evap cooling pad, pump, fan and heater down stream
Why is it okay to recirculate the air in the RW control room?
no source of potential airborne radioactivity
Where is the RW control room normal AHU located?
130’ RW building
What does RU-39 monitor?
Decon and Laundry facility Normal AFU exhaust
What happens when a RW normal AFU is shutdown?
the relative train supply AHU is also shutdown to provide negative pressure
If one train of a HR AHU/AFU is lost, What would that impact? If both trains were lost?
potentially exceed the humidity set point and require the BAC release flowrate to decrease
waste gas release would auto secure based on D/P across AFU
