Term
| Function of Reactor Vessel |
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Definition
| "1) Contain reactor core, internals and moderator; 2) Provide high integrity barrier against leakage of radioactive materials to drywell." |
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Term
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Definition
| to generate 1775 MWt such that: 1) No fuel damage occurs during normal operation and during transients; 2) Dynamic response exhibits strong negative reactivity feedback during severe plant transients and there is no inherent tendency for undamped power oscillations; 3) Sufficient reactivity is always available to make the core subcritical from its most reactive condition (sufficient shutdown margin available). |
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Term
| How many gallons per inch of moderator in the reactor vessel? |
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Definition
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Term
| Reactor Vessel design Temperature |
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Definition
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Term
| Reactor Vessel design Pressure |
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Definition
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Term
| Reactor Vessel design Core (recirc) flow |
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Definition
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Term
| Reactor Vessel design Steam flow |
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Definition
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Term
| Reactor Vessel design Feed flow |
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Definition
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Term
| State the 3 functions of a fuel channel |
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Definition
| 1) Barrier to separate flows; 2) Guides control rod blades; 3) Rigidity/protection for fuel rods. |
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Term
| State the location convention for control rods |
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Definition
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Term
| State the location convention for fuel bundles |
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Definition
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Term
| Tech Spec 3.4.9 LCO (and Applicability) and one hour (or less) Actions. |
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Definition
| "RCS pressure, RCS temperature, RCS heatup and cooldown rates, and the recirc pump starting temperature requirements shall be maintained within limits (at all times). CONDITION A: Req'ts of LCO not met in Mode 1, 2, or 3. ACTION A.1: Restore parameters within limits WITHIN 30 MINUTES. CONDITION C: Req'ts of LCO not met in other than MODES 1,2 or 3. ACTION C.1 Initiate action to restore parameter(s) to within limits IMMEDIATELY." |
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Term
| Tech Spec 3.4.2 LCO (and Applicability) |
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Definition
| All jet pumps shall be operable (in Modes 1 and 2) |
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Term
| Tech Spec 3.4.4 LCO (and Applicability) |
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Definition
RCS operational LEAKAGE shall be limited to: a. No pressure boundary leakage b. Less than or equal to 5 gpm unidentified leakage c. less than or equal to 25 gpm total leakage averaged over the previous 24 hour period d. less than 2 gpm increase in unidentified leakage within the previous period in Mode 1.
Applicability: Modes 1, 2 and 3 |
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Term
| Tech Spec 3.4.10 LCO (and Applicability) and one hour or less Actions |
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Definition
| The reactor steam dome pressure shall be less than or equal to 1025.3 psig. (in modes 1 and 2) CONDITION: Reactor steam dome pressure not within limit. ACTION: Restore to within limit WITHIN 15 MINUTES. |
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Term
| Recirc pump start temperature limits |
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Definition
| Temperature difference between the reactor coolant in the respective loop and in the reactor vessel is less than or equal to 50 degrees. |
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Term
| "RCS temperature, pressure, heatup and cooldown limits." |
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Definition
| "RCS pressure and temperature are within the limits specified in Figures 3.4.9-2 and 3.4.9-3; During heatup and cooldown, (average) rates are less than or equal to 100 degrees over a one hour period." |
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Term
| Purpose of vessel insulation |
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Definition
| Provides thermal insulation (for thermal efficiency and instrument protection) |
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Term
| Function of biological shield |
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Definition
| 1. Provides shielding to protect equipment from radiation and thermal effects; 2. Provides main protection for areas surrounding RX; 3. Assists in keeping dose ALARA. |
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Term
| "How many total vessel penetrations? Also, list those penetrations with thermal sleeves." |
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Definition
| "197. Recirc inlet, Feedwater, core spray, CRD sleeves." |
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Term
| How many steam separator standpipes? What is the moisture content of steam at the exit? |
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Definition
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Term
| What reference level is 2/3 core height? |
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Definition
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Term
| What is the moisture content of steam exiting the steam dryers? What is the concept of the steam dryers? |
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Definition
less than 0.1% moisture concept: "tortuous path"
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Term
| How many risers per loop? How many jet pumps per riser? |
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Definition
| Fiver risers per loop. Two jet pumps per riser |
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Term
| "Through a jet pump, what percentage is driven flow and what percentage is Driving flow?" |
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Definition
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Term
| Which (four) jet pumps have two instrument taps? |
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Definition
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Term
| "What are the approximate temperatures for feedwater and ""reactor"" water as they mix in the core?" |
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Definition
| Feed: approx 375 degrees; Reactor: approx 525 degrees |
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Term
| Reactor Vessel Head Seal Leak Detection setpoints |
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Definition
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Term
| State the two sizes of core orifices and their relative locations |
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Definition
| 2.1 inches (center); 1.3 inches (peripheral) |
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Term
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Definition
| To cool components between channels and suppress voiding in bypass region. |
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Term
| Describe the control rod location and fuel bundle location convention. |
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Definition
| Control rod locations list the even coordinate first. Fuel bundle locations list the odd coordinate first. Both locations follow with an odd/even coordinate respectively. |
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Term
| "List the number of fuel bundles, control rods and nuclear instrument penetrations." |
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Definition
| 484 fuel bundles; 121 control rods; 40 nuclear instrument penetrations |
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Term
| Which instruments are wet tube and which are dry? |
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Definition
| "Wet: LPRM; Dry: SRMs, IRMs, Tip Tubes" |
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Term
| Function of velocity limiter |
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Definition
| An ENGINEERING SAFETY FUNCTION that Limits freefall of uncoupled control rod blade to less than 3.11 feet per second and limit reactivity addition to less than 280 calories per gram (which protects the fuel clad). |
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Term
| What measures are in place to protect stub tubes? |
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Definition
| 1) Thermal sleeves; 2) Vessel Differential temperature limit; 3) Recirc pump start differential temperature limits. |
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Term
| List all the components supported by the stub tubes. |
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Definition
| "CRD Housing, Guide tube, CRDM, Fuel Support, Fuel Assemblies" |
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Term
| Describe the engineered safeguard feature associated with the control rod drive housing support |
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Definition
| Prevent drive ejection if a CRD stub tube weld were to fail/break. |
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Term
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Definition
| Indicates pressure drop across CORE PLATE. Can be used to measure water level by measuring static head of water but ONLY if core flow is ZERO. |
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Term
| Function of Vessel head seal flange leak detection |
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Definition
| Designed to monitor vessel head seal integrity (which is designed for zero leakage |
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Term
| function of control rod drive stub tubes |
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Definition
| "Acts as a transition piece. Supports weight of CRD housing, CRD guide tubes, CRD mechanism, fuel support piece and four fuel assemblies." |
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Term
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Definition
| Separates recirc outlet from inlet plenum. Jet pump diffusers extend through holes in baffle plate and are welded to it |
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Term
| function of baffle plate support |
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Definition
| "Supports the weight of the baffle plate, shroud, steam separator, steam dryer, top and bottom core grids and periphery fuel bundles. Transfers weight to the bottom head through legs welded to the bottom of the baffle." |
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Term
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Definition
| Separates the upward flow of the coolant through the core and the downward recirc flow in the annulus region. |
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Term
| function of core support plate |
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Definition
| "Constructed as a 2 inch thick stainless steel plate with 121 holes for the CRD guide tubes. Provides lateral support for CRD guide tubes, fuel support pieces and instrumentation guide tubes." |
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Term
| function of control rod guide tube |
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Definition
| lateral guide for control rod and vertical support for fuel support piece which holds the four fuel bundles. |
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Term
| function of fuel support piece |
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Definition
| Supports four fuel assemblies with a cruciform shaped opening to allow passage of a control rod. Each of the four lobes has an orifice to ensure proper flow to each bundle. |
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Term
| function of control rod blade |
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Definition
| Absorb thermal neutrons to control and or stop the nuclear chain reaction. |
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Term
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Definition
| Provides vertical guidance and lateral support to fuel bundles. Cross beam construction which forms squares for four fuel assemblies and one control rod blade in each squre. |
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Term
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Definition
| "Reduces moisture in steam from approx 10% to 0.03% by weight. NOTE: Skirt of dryer encloses steam separators and extends down approximately 30-40 inches below normal water level, forming a water seal for wet steam leaving the separators." |
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Term
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Definition
| Designed to ensure that possible fuel damage would not result in the release of radioactive material in excess of 10CFR limits. |
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Term
| functions of fuel channel |
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Definition
| 1) Provides a barrier to separate the two parrallel flow paths: one to cool the bundle and the other to suppress voides in the bypass region between the channels. 2) Guides the contorl rods. 3) Provides rigidity and protection for the fuel rods during handling. USAR FUNCTIONS: 1) Provide heat sink during LOCA; 2) Provide a stagnation envelope for in-core sipping; 3) Transmits fuel assembly seismic loadings to the top guide. |
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Term
| "Describe the interrelationship between feedwater, subcooled water and saturated water drain flow (from separator and dryer)" |
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Definition
| Feedwater flow enters the vessel and is distributed by its sparger. This subcooled flow is joined by saturated water drains from the steam separators and dryers and flows downward into the annular space between the vessel and the shroud. |
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Term
| Describe the interrelationship between recirc flow and jet pump flow |
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Definition
| Recirc pump takes its suction flow outside the shroud near the baffle plate. This flow is returned into the vessel by 10 risers. The flow in each riser is then directed to two jet pump nozzles. The driving flow from the nozzles (approx 42%) entrains the feedwater/drains (approx 58%) and drives the mixture through the jet pump and into the lower plenum of the vessel, having gained sufficient pressure in the process to force the required flow upward through the core. |
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Term
| Describe the flow path fo water from vessel bottom through steam separators and dryers |
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Definition
| "Water in the plenum flows through holes in the control rod guide tube, through orifices in the fuel support piece, and up through the fuel assemblies. A small fraction of the flow bypasses the core." |
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Term
| Predict impact/consenquences of Loss or malfunction of reactor recirculation |
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Definition
| A trip of both recirc pumps will result in a loss of forced core flow, with temperature stratification likely if natural circulation does not occur. RPV depressurization may be necessary to reduce temperature differential limits prior to restarting recirc pumps. |
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Term
| Predict impact/consenquences of CRD stub tube failure |
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Definition
weld failure may result in the ejection of a CRD mechanism from the core. The CRD housing support will limit travel, minimizing reactivity addition to the
core. Weld failure may also cause inventory loss. |
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Term
| Predict impact/consenquences of Jet pump failure |
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Definition
| Jet pump failure will result in a decrease in core flow and reactor power. |
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Term
| Predict impact/consenquences of Shroud access hole cover failure |
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Definition
| May decrease power levels by 15% should one come off at 100% power. Indications that may be seen are a sudden drop in core plate DP, a sudden drop in reactor power, a rise in indicated core flow or drop in ALL jet pump DPs. |
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Term
| Predict impact/consenquences of Core shroud crack |
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Definition
| Not likely to be noticed below 60% core flow. indications that may be seen are a decrease in reactor power of more than 2%, total core flow increases without a corresponding change in recirc controls, power to flow map line has lowered by more than 2%, recirc loop suction temperature increases by more than 4°F, core plate DP lowers more than 7 psid or RPV level raises, then returns to normal. |
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Term
| Predict impact/consenquences of Low temperature over pressurization events (LTOP) |
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Definition
Operating limits have been established in TS 3.4.9 to assure RPV temperature and pressures are controlled to accommodate postulated vessel material flaws without failure of the reactor vessel.
Potential injection paths which could result in a cold over pressurization of the RPV are feedwater, condensate, CRD hydraulic, SBLC, RCIC, HPCI, LPCI mode of RHR, and core spray. |
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