Nuclear fuels

Question 1

3.9.1 Boron concentration

Answer 1

3.9 REFUELING OPERATIONS
3.9.1 Boron Concentration
LCO 3.9.1 Boron concentrations of the Reactor Coolant System, the
refueling canal, and the refueling cavity shall be
maintained within the limit specified in the COLR.
APPLICABILITY: MODE 6.

Question 2

3.9.1 actions if < boron concentration from COLR

Answer 2

A.1 Suspend CORE
ALTERATIONS.
AND
A.2 Suspend positive
reactivity additions.
AND
A.3 Initiate action to
restore boron
concentration to
within limit.

Question 3

3.9.2 unborated water isolation valves

Answer 3

3.9 REFUELING OPERATIONS
3.9.2 Unborated Water Source Isolation Valves
LCO 3.9.2 Each valve used to isolate unborated water sources shall be
secured in the closed position.
APPLICABILITY: MODE 6.
ACTIONS
————————————-NOTE————————————-
Separate Condition entry is allowed for each unborated water source isolation
valve.
——————————————————————————

Question 4

3.9.3 Nuclear instrumentation

Answer 4

3.9 REFUELING OPERATIONS
3.9.3 Nuclear Instrumentation
LCO 3.9.3 Two source range neutron flux monitors shall be OPERABLE.
APPLICABILITY: MODE 6.

Question 5

3.9.4 Containment penetrations

Answer 5

3.9 REFUELING OPERATIONS
3.9.4 Containment Penetrations
LCO 3.9.4 The containment penetrations shall be in the following
status:
a. One door in the personnel air lock closed and the
equipment hatch held in place by  4 bolts;
b. One door in the emergency air lock closed; and
c. Each penetration providing direct access from the
containment atmosphere to the outside atmosphere closed
by a manual or automatic isolation valve, blind flange,
or equivalent.
—————————-NOTE—————————-
LCO 3.9.4.a is not required to be met when in compliance
with LCO 3.7.13, “Fuel Handling Building Exhaust Filter
Plenum (FHB) Ventilation System,” or its associated
Conditions and Required Actions.
————————————————————
APPLICABILITY: During movement of RECENTLY IRRADIATED FUEL assemblies
within containment.

Question 6

3.9.5 RHR and coolant circulation- high water level

Answer 6

3.9 REFUELING OPERATIONS
3.9.5 Residual Heat Removal (RHR) and Coolant Circulation-High Water Level
LCO 3.9.5 One RHR loop shall be OPERABLE and in operation.
—————————-NOTE—————————-
The required RHR loop may be removed from operation for
<= 1 hour per 8 hour period, provided no operations are
permitted that would cause reduction of the Reactor Coolant
System boron concentration.
————————————————————
APPLICABILITY: MODE 6 with the water level >= 23 ft above the top of reactor
vessel flange.

Question 7

3.9.6 RHR and coolant circulation-low water level

Answer 7

3.9 REFUELING OPERATIONS
3.9.6 Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level
LCO 3.9.6 Two RHR loops shall be OPERABLE, and one RHR loop shall be
in operation.
—————————-NOTE—————————-
One required RHR loop may be removed from operation and
considered OPERABLE:
a. To support filling and draining the reactor cavity when
aligned to, or during transitioning to or from, the
refueling water storage tank provided the required RHR
loop is capable of being realigned to the Reactor
Coolant System (RCS); or
b. To support required testing provided the required RHR
loop is capable of being realigned to the RCS.
————————————————————
APPLICABILITY: MODE 6 with the water level < 23 ft above the top of reactor
vessel flange.

Question 8

3.9.7 Refueling cavity water level

Answer 8

3.9 REFUELING OPERATIONS
3.9.7 Refueling Cavity Water Level
LCO 3.9.7 Refueling cavity water level shall be maintained >=23 ft
above the top of reactor vessel flange.
APPLICABILITY: During movement of irradiated fuel assemblies within
containment.

Question 9

Nuclear fuel- purpose

Answer 9

Purpose
Generate Heat through fission under safe conditions.
Transfer heat to RCS
Retain radioactive fission products over long cycle life.

Question 10

What is used as a cover gas inside fuel rods?

Answer 10

Helium gas pressurizes fuel pin (about 100-275 psig)
Improves heat transfer between pellet and clad
Inert gas
Minimizes clad creep (compressive deformation where clad tends to compress)
Pressure becomes 1800-2000 psig at hot, EOL conditions.

Question 11

How many rods in each Bank?

Answer 11

CB A-4 B-8 C-8 D-5

SDB A-8 B-8 C-4 D-4 E-4

Question 12

4.2 Design features, how many control rods and what material

Answer 12

The reactor core shall contain 53 control rod assemblies. The
control material shall be silver indium cadmium, hafnium, or a
mixture of both types.

Question 13

4.3 design features, fuel storage

Answer 13

<= 0.95 Keff, no more than 5.0 % enrichment, no draining below 410’0”, no more than 2984 fuel assemblies

Question 14

Types of detectors for excores:

Answer 14

SR Fission chambers
IR Fission chambers
PR Uncompensated ion chamber

Question 15

Heat flux hot channel factor- Fq(Z)

Answer 15

Heat Flux Hot Channel Factor – FQ(Z)
Limit Local (i.e., pellet) peak power density
Varies along axial height of core
Measures peak fuel pellet power

Question 16

3.2.1 power dist limit, Fq(Z)

Answer 16

LCO 3.2.1, withing limit specified in colr
Reduce THERMAL POWER
>= 1% RTP for each
1%
F (Z)
C
Q
exceeds
limit.
within 15 minutes

Question 17

3.2.2 Nuclear enthalpy rise hot channel factor

Answer 17

3.2 POWER DISTRIBUTION LIMITS
3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F )
N
H
LCO 3.2.2 N FH shall be within the limit specified in the COLR.
APPLICABILITY: MODE 1

Reduce power <50% within 4 hours

Question 18

3.2.3 AFD

Answer 18

3.2 POWER DISTRIBUTION LIMITS
3.2.3 AXIAL FLUX DIFFERENCE (AFD)
LCO 3.2.3 The AFD shall be maintained within the limits specified in
the COLR.
—————————-NOTE—————————-
The AFD shall be considered outside limits when two or more
OPERABLE excore channels indicate AFD to be outside limits.
————————————————————
APPLICABILITY: MODE 1 with THERMAL POWER >= 50% RTP.

IF AFD not within limits, reduce power to <50% within 30 minutes

Question 19

3.2.4 QPTR

Answer 19

3.2 POWER DISTRIBUTION LIMITS
3.2.4 QUADRANT POWER TILT RATIO (QPTR)
LCO 3.2.4 The QPTR shall be <= 1.02.
APPLICABILITY: MODE 1 with THERMAL POWER > 50% RTP when Power Distribution
Monitoring System (PDMS) is inoperable.

A.1 Reduce THERMAL POWER          2 hours
>= 3% from RTP for
each 1% of QPTR
> 1.00.
AND
A.2 Determine QPTR and                   12 hours
reduce THERMAL POWER
>=3% from RTP for
each 1% of QPTR
> 1.00.