ML20151U201
| ML20151U201 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/03/1998 |
| From: | SOUTHERN NUCLEAR OPERATING CO. |
| To: | |
| Shared Package | |
| ML20151U198 | List: |
| References | |
| NUDOCS 9809100322 | |
| Download: ML20151U201 (28) | |
Text
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ENCLOSURE 4 VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS REPLACEMENT OF NUCLEAR INSTRUMENTATION SYSTEM SOURCE AND INTERMEDIATE RANGE CHANNELS AND POST-ACCIDENT NEUTRON FLUX N
MQ_N.lTORING SYSTEM i
MARKED-UP REVISIONS TO TECIINICAL SPECIFICATION AND BASES PAGES l
l i
i 9809100322 980903 l PDR ADOCK 05000424' P PDR :.2
l l
RTS Instrumentation 3.3.1 !
j SURVEILLANCE REOUIREMENTS / continued)
FREQUENCY SURVEILLANCE SR 3.3.1.8 -------------------NOTE-------------------- l' Only required when not performed within previous 31 days. ;
Prior to !
Perform COT. Reactor Startup 1
I SR 3.3.1.9 -------------------NOTE----------------d.
Verification of setpoint is not require 92 days Perform TADOT.
SR 3.3.1.10 -------------------NOTE--------------------
. This Surveillance shall include verification' that the time constants are adjusted to the prescribed values.
18 months Perform CHANNEL CALIBRATION.
SR 3.3.1.11 ------------------NOTES--------------------
,,}<' Neutron detectors are excluded from CHANNEL CALIBRATION.
- 2. P:::r :r.d Ir.t:. ,;.;dt:t: P.::;: d:t::t:r pi;;;; v;?t:;: 7:ri'i::ti : i: ::t i y .. .d te be.p;. ._ .. .
fe. ..cd pri;r t:
...., ...........4 18 months Perform CHANNEL CALIBRATION.
(continued)
Amendment No. 96 (Unit 1) 3.3 11 (Unit 2)
Vogtle Units 1 and 2 Amenoment No. 74 l
l RTS Instrumentation 3.3.1 l
l Table 3.3.1 1 (page 1 of 8)
Reactor Trip System Instrunentation APPLICABLE MODES l NOMINAL l OR DTHER l
SPECIFIED REQUIRED SURVEILLANCE ALLOWABLE TRIP CHANNELS CON 0lf!ONS REQUIREMENTS VALUE SETPOINT IAI l FUNCT!0N CON 0lTIONS l
SR 3.3.1.13 NA NA
- 1. Manual Reactor 1,2 2 B i Trip 3(a), 4(a), $(a) C SR 3.3.1.13 NA NA l 2 1
- 2. Power Range Neutron Flux 1,2 4 0 SR 3.3.1.1 s 111.3% RTP 109% RTP l
- a. High SR 3.3.1.2
$R 3.3.1.7 st 3.3.1.11 SR 3.3.1.15 1(D3,2 4 E SR 3.3.1.1 1 27.3% RTP 25% RTP l
- b. Low st 3.3.1.8 st 3.3.1.11 SR 3.3.1.15
$R 3.3.1.7 5 6.3% liTP $1 RTP l
- 3. Power Range 1,2 4 E Neutron Flux High $2 3.3.1.11 with time with time constant constant Positive Rate t 2 see t 2 sec 41 9);
$R 3.3.1.1 s $t-+%-RTP 25% RTP l 4 Intermediate Range 1(b), 2(CI 2 F,G Neutron Flux SR 3.3.1.8 SR 3.3.1.11 41 9 ?o SR 3.3.1.1 5 9W99 RTP 25% RTP l 2(d) 2 H SR 3.3.1.8 i
' SR 3.3.1.11 (continued)
(a) With Reactor Trip Breaters (RTBs) closed and too Control System cap".ols of rod withdrawal.
(b) Below the P 10 (Power Range Neutron Flux) interlocks.
(c) Above the P 6 (Intermediate Range Neutron Flux) interlocks.
(d) Below the P 6 (Intermediate Range Neutron Flux) interlocks.
s calibration tolerance bana provided the (n) A channel- is OPERA 8LE with an actual Trip setpoint value outsidi Trip setpoint value is conservative with respect to its associa. J Allowable value and the A cnannel is re-Trip 5etpoint adjusted to within the established calibration tolerance band of the Nominal Trip setpoint.
may be set more cc.~rvative than the Nominal Trip Setpoint as necessary in response to plant conditions.
l l
3.3-14 Amendment No. ' 01(Unit 1)
Vogtle Units 1 and 2 Amendment No. 9(Unit 2)
RTS Instrumentation 3.3.1 fatte 3.3.1 1 (page 2 of 8) teactor Trip $ystem instrumentation APPLICA8LE wCDES NOMINAL l 04 OthER ALLOWABLE TRIP
$URVEILLANCE SPECIF'ED REQUIRED VALUE SETPOINT(n) l CHANNELS CON 0lfl0NS REQUIREMENTS FUNCTION CON 0lf!ONS 1.1 1 ++ E 5 1.0 E5 l 2 1,J st 3.3.1.1 cps Source Range 2(83 cps
- 5. st 3.3.1.8 deutron Flux SR 3. 3. 1.11-5 4,6 E5 1.0 E5 l J,K st 3,'i.1.1 3(a), 4(a), $(a) 2 SR 7.3.1.7 cps eps
$t 3.3.1.11
- " 3.3.' :
NA NA 3(*), l.;'), 5(') 1 L SR 3.3.1.1 SR 3.3.1.11 Refer t: Refer to 4 E SR 3.3.1.1 Note 1
- 6. Overtencerature et t.2 SR 3.3.1.3 Note 1 (Page (Pese st 3.3.1.6 3.3 20)
SR 3.3.1.7 3.3 20) sa 3.3.1.10 sa 3.3.1.15 Refer t: Refer to 4 E SR 3.3.1.1 Note 2
- 7. Os erswer AT t,2 st 3.3.1.7 Note 2 (Page (Pete sR 3.3.1.10 3.3<21) sa 3.3.1.15 3.3-21)
(continued)
(a) With RTBs closed and Rod Contret System cacaote of red withdrawal. 1 intertects.
(d) Selow the P 6 (Intermeciate Range heutron Flux) does prov %
In this cenoition, source range Function does not provide reactor trip est (e) With the RT5s open.
input to the High Flux at Shutoown Alarm System (LCD 3.3.8) ano indication. o provided the l is re*
(n) A channel is OPERA 8LE with an actual Trio setpoint value 1 Trip Setpointoutside adjusted to within the estselisned catibratton tolerance band of the Nominal l nt conditions.
Trip Setpoint.
may be set more conservative teen the Nominal Trip 5etpoint as necessary in response to p a 1
! i i
l 3.3-15 Amenament tio. ' 21(Unit 1)
Vogtle Units 1 and 2 Amencment flo. ~9(Unit 2) l 1
i
_ _ . ~ . _ . _ _ . _ . _ _ _. _ __
RTS Instrumentation r 3.3.1 l
'able 3.3.1 1 (page 5 of 8)
Reac;or Trio System Instrunentation I
APPLICABLE R.10E5 NOMINAL l OR OTHER i
REQUIRED SURVEILLANCE ALLOWABLE TRIP SETPOINT IOI SPECIFIED CHANNELS CON 0lfl0NS REQUIREMENTS VALUE l FUNCTION CONDITIONS i
i
- 14. Turbine Trip ill) 0 sa 3.3.1.10 t 500 psig 580 psig l
- s. Low Fluid oil 3 Pressure SR 3.3.1.16 st 3.3.1.10 t 90% 96.7% l l
- b. Turbine stop 1(N 4 P open
$R 3.3.1.14 open Valve Closure l
- 15. safety 1,2 2 trains o st 3.3.1.13 NA NA Injection (51)
Input from Engineered Safety Feature Actuation System (ESFA5) l l
- 16. Reactor Trip System interlocks y g,og52RTP 2(dl 2 a st 3.3.1.11 .Zs % % -- l
- a. Intermediate i Range Neutron $R 3.3.1.12 Flux, P 6 l
$R 3.3.1.5 NA NA
- b. Low Power 1 1 per S Reactor Trips train Stock, P 7 SR 3.3.1.11 5 50.3% RTP 48% RTP l 4 5
- c. Power Range g SR 3.3.1.12 Neutron Flux, P8 ,
4 5 SR 3.3.1.11 5 52.3% RTP 50% RTP l
- d. Power Range st 3.3.1.12 Neutron Flum, 1 P9 SR 3.3.1.11 (1,m) (L,m)
Power Range 4 R
- e. SR 3.3.1.12 Neutron Flux, 1.2 Paio and input to Pa7 st 3.3.1.10 s 12.3% 10% i 2 s 1 SR 3.3.1.12 lapulse lasualse
- f. Turbine lupulse Pressure Pressure Pressure, P 13 Equivalent Equivalent turbine turbine (continued)
(d) Below the P 6 (Intermediate Range Neutron Flum) interlocks.
(j) Above the P 9 (Power Range Neutron Flum) interlock.
is 10% RTP. l (L) for the P 10 input to P 7, the Allowable Value is s 12.3% RTP and the Nominal Trip Setpoint the Nominal Trip Setpoint is l (C) For the Power Range Neutron Flux, P 10, the Allowable value is t 7.7% RTP ent' 10% RTP.
l l (n) A channel is OPERABLE with an actual Trip setpoint value outside its calibration tolerance cand provided the Trip $etpoint value is conservative with respect to its associated Allowable Value and Athe enannel Trip $etpointis re*
adjusted to within the estantished calibration tolerance band of the Nominal Trip 5etpoint. conditions, may be set more conservative than the Nominal Trip Setpoint as necessary in response to plant f
l 3.3-18 Amendment No.101(Unit 1)
Vogtle Units 1 and 2 Amendment No. '9(Unit 2)
RTS Instrumsntaticn B 3.3.1 1
BASES-
- 4. Intemediate Ranae Neutron Flux (continued)
APPLICABLE SAFETY ANALYSES, Above the F-10 setpoint, the Power Range Neutron LCO, and g*
Flux - High Setpoint trip and the Power Range Neutron yo APPLICABILITY Flux - High Positive Rate trip provide core In MODE 3, protection 4, or 5. jE for a rod. withdrawal accident.
the Intermedicte Range Neutron Flux trip does not have ).2 9"M to be OPERABLE because #E up in this condition. The corethealsoreactor has thecannot requiredbe started SDM to mitigate the consequences of a positive 'U j In MODE 6, all rods are reactivity addition accident. ; 4: w%$p/
fully inserted and the core has a required increased 8 SDM. Also, the NIS intermediate rangeN : ::::r: "^^E. %-2
- :::t d:t::t ::t,:: ?:c:?: pr::::: " thi: ES ,
- 5. Source Ranoe Neutron Flux The LCO requirement for the Source Range Neutron Flux trip (NI-0031B, D, & E. NI-00328, D & G) Function ensures that protection is provided against an uncontrolled RCCA bank rod withdrawal This accident trip from a subcritical condition during startup.
Function provides redundant protection to the Power Range Neutron Flux - Low Setpoint and Intemediate In MODES 3, 4, Range Neutron Flux trip Functions.
and 5, administrative controls alsoThe prevent the range NIS source uncontrolled withdrawal of rods.
detectors are located external to the reactor The NISvessel and measure neutrons leaking from the core.
source range detectors do not provide any inputs to control systems. The source range trip is the only RTS automatic protection function required in MODES 3, 4, and 5. Therefore, the functional capability at the specified Trip Setpoint is assumed to be available.
The LCO requires two channels of Source Range Neutron Flux to be OPERABLE. Two OPERABLE channels are sufficient-to ensure no single random failure will disable this trip Function. The LCO also requires two
. channels of the Source Range Neutron Flux to be t" OPERABLE in MODE 3, 4, or 5 with RTBs closed.
The Source Range Neutron Flux function provides protection for control rod withdrawal from
)
(continued) l Revision No. 0 B 3.3-13 Vogtle Units 1 and 2
RTS Instrumentation !
8 3.3.1 i
- l 4
} BASES !
1 APPLICABLE 5. Source Rance Neutron Flux (continued)
SAFETY ANALYSES, i
! LCO, and suberitical, boron dilution (see LC0 3.3.8) and APPLICABILITY control rod ejection events. The Function also 3
provides visual neutron flux indication in the control room. l
- )
In MODE 2 when below the P-6 setpoint during a reactor 4
startup, the Source Range Neutron Flux trip must be .
OPERABLE. Above the P-6 setpoint, the Intemediate j
Range Neutron Flux trip and the Power Range Neutron
)
! Flux - Low Setpoint trip will provide core protection l j
for reactivity accidents. Above the P-6 setpoint, the 1
2 --- a ..a . a 5 $5;;$55555. ' '5c"u'rc~e i$'h he$ o'n~FId hip"r i"61 oc ked .
{
I In MODE 3, 4, or 5 with the reactor shut down, the Source Range Neutron Flux trip Function must also be i
If the Rod Control System is capable of rod withdrawal, the Source Range Neutron Flux trip must be j
OPERABLE to provide core protection against a rod i
withdrawal accident. If the Rod Control System is not capable of rod withdrawal, the source range detectors are not required to trip the reactor. Source range detectors also function to monitor for high flux at shutdown. This function is addressed in Specification 3.3.B. Requirements for the source range detectors .in MODE 6 are addressed in LCO 3.9.3.
l 6. Overtemocrature AT I
' The Overtemperature AT trip Function (TDI-0411C, i
' TDI-0421C, TDI-0431C, TDI-0441C, TDI-0411A, TDI-0421A, l TDI-0431A, TDI-0441A) is provided to ensure that the design litit DNBR is met. This trip Function also limits the range over which the Overpower AT trip l
Function must provide protection. The inputs to the Overtemperature AT trip include pressure, coolant temperature, axial power distribution, and reactor power as indicated by loop AT assuming full reactor coolant flow. Protection from violating the DNBR limit is assured for those transients that are slow with respect to delays from the core to the measurement system. The Function monitors both variation in power and flow since a decrease in flow (continued)
L 8 3.3-14 Revision No. O Vogtle Units 1 and 2
1 RTS Instrumsntaticn l
B 3.3.1 l
BASES APPLICABLE 16. Reactor Trio System Interlocks SAFETY ANALYSES, LCO, and Reactor protection interlocks are provided to ensure APPLICABILITY reactor trips are in the correct configuration for the (continued) current unit status. They back up operator actions to ensure protection system Functions are not bypassed l during unit conditions under which the safety analysis l assumes the Functions are not bypassed. Therefore, the interlock Functions do not need to be OPERABLE when the associated reactor trip functions are outside the applicable MODES. These are:
l
- a. Intemediate Ranae Neutron Flux. P-6 The Intemediate Range Neutron Flux, P-6 interlock (NI-0035B, D, & E. N1-0036B. D, & G) is actuated when any NIS intermediate range channel goes approximately one decade above the minimum channel reading. If both channels drop below the setpoint, the pemissive will automatically be defeated. The LCO requirement for the P-6 interlock ensures that the following Functions are performed:
- on increasing power, the P-6 interlock l allows the manual block of the NIS Source Range, Neutron Flux reactor trip. This i prevents a premature block of the source l range trip and allows the operator to ensure that the intemediate range is OPERABLE prior to leaving the source range.
L'h:n th: :;;r:: r;ng: trip i: b!:cked, the hip, jtegg t; th; dctcet;rs is ;ise-
- on decreasing power, the P-6 interlock automatically ;n qi::: th: MIS ;;;r; reag; det;;ter; :nd enables the NIS Source Range Neutron Flux reactor trip.
The LCO requires two channels of Intemediate Range Neutron Flux, P-6 interlock to be OPERABLE in @DE 2 when below the P-6 interlock setpoint.
' (continued) 8 3.3-29 Revision No. O Vogtle Units 1 and 2
1 k
RTS Instrumintation B 3.3.1 BASES l APPLICABLE d. Power Ranae Neutron Flux. P-9 (continued)
SAFETY ANALYSES, LCO, and reactor is not at a power level sufficient to ;
APPLICABILITY have a load rejection beyond the capacity of the Steam Dump System.
i
- e. Power Rance Neutron Flux. P-10 The Power Range Neutron Flux, P-10 interlock (NI-0041B & C, NI-00428 & C, NI-00438 & C, NI-0044B & C) is actuated at approximately 10%
power, as determined by two-out-of-four NIS power range detectors. If power level falls below 10% RTP on 3 of 4 channels, the nuclear '
instrument trips will be automatically unblocked.
The LCO requirement for the P-10 interlock ensures that the following Functions are perfomed:
- on increasing power, the P-10 interlock allows the. operator to manually block the Intemediate Range Neutron Flux reactor trip. Note that blocking the reactor trip also blocks the signal to prevent automatic and manual rod withdrawal;
- on increasing power, the P-10 interlock allows the operator to manually block the Power Range Neutron Flux - Low reactor trip;
- on increasing power, the P-10 interlock automatically provides a backup signal to block the Source Range Neutron Flux reactor tripp :d c h : t: d: ::: gi:: th: "!S
-sar:: r_;;; d::::::r:;
e the P-10 interlock provides one of the two inputs to the P-7 interlock; and
- on decreasing power, the P-10 interlock automatically enables the Power Range Neutron Flux - Low reactor trip and the Intemediate Range Neutron Flux reactor trip (and rod stop).
(continued)
B 3.3-33 Revision No. 0 vogtle Units l'and 2
RTS Instrum2ntation B 3.3.1 BASES SURVEILLANCE SR 3.3.1.10 RE0VIREMENTS.
A CHANNEL CALIBRATION is performed every 18 months, or (continued) approximately at every refueling. CHANNEL CAL 1BRATION is a l complete check of the instrument loop, including the sensor. '
The test verifies that the channel responds to a measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATIONS must be performed consistent with the The assumptions of the unit specific setpoint methodology.
difference between the current "as found" values and the previous test "as left" values must be consistent with the '
drift allowance used in the setpoint methodology.
The frequency of 18 months is based on the assumption of an I 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint methodology for some instrument functions, and the need to perfom this Surveillance for some instrument functions under the conditions that apply during a plant outage and the potential for an unplanned plant transient if the Surveillance were perfomed at power. Operating exoerience ;
has shown these components usually pass the Surveillance when perfomed on the 18 month Frequency.
SR 3.3.1.10 is modified by a Note stating that this test shall include verification that the time constants are adjusted to the prescribed values where applicable.
SR 3.3.1.11 dN6N t SR 3.3.1.11 is the perfomance of a CHANNEL This CALIBRATION, as SR is 18 months.
described in SR 3.3.1.10,:::t: every" 1 states that neutron detectors modified by : : :: t::. The CHANNEL are excluded from the CHANNEL CALIBRATION. inc/udes CALIBRATION for the power range neutron detectors ::::izt:
g3
-e+ a nomalization of the detectors based on a nowerThe calorimetric and flux map perfomed above 50%fRTP. rdSt-CHANNEL CALIBRATION for the source range : d "t '"g 09oDtaining tne cetector rc:; neutron detectors :;.,;i:t:
pl:t::: er preamp discriminator curves and evaluating those curves. ::::: 2 : :::: th:t the phter: ::!!:;: e r r"i e:ti e-(continued)
Revision No. O B 3.3-56 Vogtle Units 1 and 2
RTS Instrum:ntation B 3.3.1 BASES SR 3.3.1.11 (continued)
SURVEILLANCE ....;.a;. .e oc.d REQUIREMENTS :::fr:d f;r th; N:: e;-, .;r ; ..p i:::::: th: crit ::t i: ::
etrt:r: I:;;; "00
- - ::try Ht: "^0: mt f;i th; t: ir ::
2 te ,;;. fe.;r.d
. J,"00: I f;r th: ;; r ::;:
int;..:di::: r;;;; d::::t;r:
The 18 month Frequency is based on the need to d:t::::r:.
perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were perfomed with the reactor at power. Operating experience has shown these components usually pass the Surveillance when performed on the 18 month Frequency.
SR 3.3.1.12 SR 3.3.1.12 is the performance of a COT of RTS interiocks every 18 months.
The Frequency is based on the known reliability has been shown to be acceptable through operating experience.
Sft 3.3.1.13 SR 3.3.1.13 is the performance of a TADOT of the ManualThis T !
J Reactor Trip and the SI Input from ESFAS. describe j
)
every 18 months.
The manual reactor trip TADOT shall independently verify the OPERABILITY of the undervoltage This testano shunt shall alsotrip circuits for the manual reactor trip function.
verify the OPERASILITY of the Bypass breake The Frequency is based on the known relia been snown to be acceptable through operating experience.
f (continued)
~
Revision No. 0 i B 3.3-57 Vogtle Units 1 and 2 .
HFASA Instrumentation B 3.3.8 l
B 3.3 INSTRUMEN1ATION B 3.3.8 High Flux ^at Shutdown Alarm (HFASA)
BASES BACKGROUND The primary purpose of the HFASA is to warn the operator of an unplanned boron dilution event in sufficient time (15 minutes prior to loss of shutdown margin) to allow manual action to terminate the event. The HFASA is used for this purpose in MODES 3 and 4, and MODE 5 with the loops filled.
The HFASA consists of two channels of alarus, with each channel receiving input from one source range channel. An alarm setpoint of t2.3 times background provides at least 15 dE
- minutes from the time the HFASA occurs to the total This loss of shutdown margir, due to an unplanned dilution event.
meets the Standard Review Plan criteria for mitigating the
' consequences of an unplanned dilution event by relying on operator action.
'1 l
i i
- APPLICABLE The analysis presented in Reference 1 identifies credible !
SAFETY ANALYSES boron dilution initiators. Time intervals from the HFASA l until loss of shutdown margin were calculated. The results demonstrate that sufficient time for operator response is available .to terminate an inadvertent dilution event taking credit for one HFASA with a setpoint of 2.3 times background. 6 The HFASA satisfied Criterion 3 of the NRC Policy Statement..
1- The LCO requires two channels of HFASA to be OPERABLE with
- LCO input from two source range channels to provide protection against single failure.
I l
The HFASA must be OPERABLE in MODES 3, 4, and 5. l 1
APPLICABILITY The Applicability is modified by a Note which allows the l HFASA to be blocked in MODE 3 during reactor startup so that J spurious alarms are.not generated.
)
(continued) t 8 3.3-171 Revision No. O Vogtle Units 1 and 2 p
a e , -
-, , y .n.~ ., ... . . . _ , , . w
Nuclear Instrumentatien B 3.9.3 B 3.9 REFUELING OPERATIONS B 3.9.3 Nuclear Instrumentation BASES BACKGROUND The source range neutron flux monitors are used during refueling operations to monitor the core reactivity condition. The installed source range neutron flux monitors (NI-0031 and NI-0032) are part of the Nuclear Instrumentation System (NIS). These detectors are located external to the reactor vessel and detect neutrons leaking from the core. Temporary neutron flux detectors which provide equivalent indication may be utilized in place of installed instrumentation.
The installed source range neutron flux monitors are WS-fission charnher detectors. ;:r ting in th: pr:p:rti:::! regie Of the g::
fill;d d;;;;t:r ch r::::ri:ti: : r::. The detectors monitor the neutron flux in counts per second. The instrument range Seve,n covers +s4*- decades of neutron flux ('05 cp) with a,IW.2 %
instrument accuracy. The detectors so provide continuous visual indication in the control room. The NIS is designed in accordance with the criteria presente in Reference 1.
OE-lces to IEt6 cps)
APPLICABLE Two OPERA 8LE raurce range neutron flux monitors are required SAFETY ANALYSES to provide a signal to alert the operator to unexpected changes in co e reactivity such as an improperly loaded fuel assemoly. The need for a safety analys1s for an uncontrolled boron dilution accident is minimized by isolating all unborated water sources except as provided for by LCO 3.9.2, "Unborated Water Source Isolation valves."
The source range neutron flux monitors satisfy Criterion 3 of the NRC Policy Statement.
LCO This LCO requires that two source range neutron flux monitors be OPERABLE to ensure that redundant monitoring capability is available to detect changes in core reactivity. To be OPERABLE each monitor must provide visual indication.
l 1
(continued) 8 3.9-9 Revision No. O I Vogtle Units 1 and 2
Nuclear Instrum2ntation B 3.9.3 BASES ACTIONS M (continued) are OPERABLE.
This stabilized condition is determineo by performing SR 3.9.1.1 to ensure that the required boron concentration exists.
The Completion Time of once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is suff cient to e for or n obtain and analyze a reactor coolant s t unp concentration and to en re ,
concentration would be i en .
Time is reasonable, considering the Iow probability of a change in core reactivity during this time perio .
SURVEILLANCE SR 3.9.3.1 l REQUIREMENTS SR 3.9.3.1.is the performance of a CHANNEL CHECK, which is a l comparison of the parameter indicated on one channel to a similar parameter on other channels. It is based on the assumption that the two indication channels should be Changes in fuel loading consistent with core conditions. ;
and core geometry can result in significant differences '
between source range channels, but each channel should be consistent with its local conditions.
The Frecuency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is consistent with the CHANNEL CHECK in LCO 3.3.1, Frequency " Reactor Tripspecified System similarly(for the same instrume RTS) Instrumentation."
SR 3 . 9 . 3 . 2_
SR 3.9.3.2 is the performance of a CHANNEL CALIBRATION every 18 months.
This SR is modified by a Note stating that neutron detectors are excluded from the CHANNEL CALIBR The CHANNEL CALIBRATIDH for the source range neutron flux
/nc/ude.s monitorsi m :i:t: Of obtaining the detector p?:t: n er preamp discriminator curves and evaluating those c Surveillance under the conditions that apply during a plant outage. Operating experience has shown these components usually pass the Surveillance when perfomed at the 18 month 4
Frequency.
(continued)
Revision No. 0 B 3.9-11 Vogtle Units 1 and 2
. -- _ . - _- _ . - - . . . - . _ . . . ~ . . - - . .
ENCLOSURE 5 VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS REPLACEMENT OF NUCLEAR INSTRUMENTATION SYSTEM SOURCE AND INTERMEDIATE RANGE CilANNELS AND POST-ACCIDENT NEUTRON FLUX MONITORING SYSTEM TYPED REVISED TECilNICAL SPECIFICATION AND BASES PAGES 1
l
RTS Instrumentation 3.3.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.8 -------------------NOTE--------------------
Only required when not performed within previous 31 days.
Perform COT. Prior to Reactor Startup 1
SR 3.3.1.9 -------------------NOTE--------------------
Verification of setpoint is not required.
Perform TAD 0T. 92 days l
SR 3.3.1.10 -------------------NOTE--------------------
This Surveillance shall include ;
verification that the time constants are adjusted to the prescribed values. ;
Perform CHANNEL CALIBRATION. 18 months l
l SR 3.3.1.11 ------------------NOTE--------------------- l l Neutron detectors are excluded from CHANNEL i CALIBRATION. l l l
l Perform CHANNEL CALIBRATION. 18 months (continued)
Vogtle Units 1 and 2 3.3-11 Amendment No. (Unit 1)
Amendment No. (Unit 2) ;
1 l
1
RTS Instrumentation
( 3.3.1 Table 3.3.1-1 (page 1 of 8)
Reactor Trip System Instrumentation APPLICABLE MODES OR OTHER WOMINAL SPECIFIED REQUIRED SURVEILLANCE ALLOWABLE TRIP FUNCTION CONDITIONS CHANNELS CONDITIONS REQUIREMENTS VALUE SETPolNT(n)
- 2. Power Range Neutron Flux
- a. High 1,2 4 0 SR 3.3.1.1 s 111.3% RTP 109% RTP SR 3.3.1.2 SR 3.3.1.7 SR 3.3.1.11 SR 3.3.1.15
- b. Low 1(b) 2 , 4 E SR 3.3.1.1 5 27.3% RTP 25% RTP SR 3.3.1.8 SR 3.3.1.11 SR 3.3.1.15
- 3. Power Range 1,2 4 E SR 3.3.1.7 s 6.3% RTP 5% RTP Neutron Flux High SR 3.3.1.11 with time with time Positive Rate constant constant t 2 see t 2 sec
- 4. Intermediate Range 1(b), 2(83 2 F,G SR 3.3.1.1 5 41.9% RTP 25% RTP l Neutron Flux SR 3.3.1.8 SR 3.3.1.11 2(d3 2 H SR 3.3.1.1 s 41.9% RTP 25% RTP l SR 3.3.1.8 SR 3.3.1.11 (continued)
- (a) With Reactor Trip Sreakers (RTBs) closed and Rod Control System capable of rod withdrawal.
(b) Below the P 10 (Power Range Neutron Flux) intt-locks.
(c) Above the P-6 (Intermediate Range Neutron Flux) interlocks.
(d) Below the P 6 (Intermediate Range Neutron Flux) Interlocks.
(n) A channel is OPERA 8LE with an actual Trip setpoint value outside its calibration tolerance band provided the Trip setpoint value is conservative with respect to its associated Allowable Value and the channel is re-adjusted to within the established calibration tolerance band of the Nominal Trip Setpoint. A Trip Setpoint may be set more conservative than the Nominal Trip Setpoint as necessary in response to plant conditions.
t I~
i l
l
! Vogtle Units 1 and 2 3.3-14 Amendment No. (Unit 1)
Amendment No. (Unit 2)
RTS Instrumsntation 3.3.1 Table 3.3.1 1 (page 2 of 8)
Reactor Trip System Instrumentation APPLICABLE MODES OR OTHER NOMINAL SPECIFIED REQUIRED SURVEILLANCE ALLOWABLE TRIP FUNCTION CONolTIONS CHANNELS CONDITIONS REQUIREMENTS VALUE SETPOINT("I
- 5. Source Range 2(d) 2 1,J SR 3.3.1.1 5 1.7 E5 1.0 E5 l Neutron Flux SR 3.3.1.8 cps cpa SR 3.3.1.11 1
3(a), 4(a), $(a) 2 J,K SR 3.3.1.1 5 1.7 E5 1.0 E5 l SR 3.3.1.7 cps eps SR 3.3.1.11 1
3('), 4('), 5(') 1 L SR 3.3.1.1 NA NA SR 3.3.1.11
- 6. Overtenperature &T 1,2 4 E SR 3.3.1.1 Refer to Refer to SR 3.3.1.3 Note i Note 1 SR 3.3.1.6 (Page (Page SR 3.3.1.7 3.3 20) 3.3-20)
- 7. Overpower AT 1,2 4 E SR 3.3.1.1 Refer to Refer to SR 3.3.1.7 Note 2 Note 2 SR 3.3.1.10 (Page (Page l
SR 3.3.1.15 3.3 21) 3.3-21)
(continued)
(a) With RTBs closed and Rod Control System capable of rod withdrawal.
(d) Below the P-6 (Intermediate Range Neutron Flux) Interlocks.
(e) With the RTBs open. In this condition, source range Function does not provide reactor trip but does provide input to the High Flux at Shutdown Alarm System (LCO 3.3.8) and indication.
l (n) A channel is OPERA 8LE with an actual Trip Setpoint value outside its calibration tolerance band provided the Trip setpoint value is conservative with respect to its associated Allowable Value and the channel is re-adjusted to within the established calibration tolerance band of the Nominal Trip Setpoint. A Trip Setpoint may be set more conservative than the Nominal Trip Setpoint as necessary in response to plant conditions.
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Vogtle Units 1 and 2 3.3-15 Amendment No. (Unit 1)
Amendment No. (Unit 2)
1 1
RTS Instrumentation 1 3.3.1 i l
Table 3.3.1 1 (page 5 of 8) i Reactor Trip System Instrumentation l l
APPLICABLE MODES OR OTHER NOMINAL SPECIFIED REQUIRED SURVEILLANCE ALLOWASLE TRIP FUNCTION CONDITIONS CMANNELS CONDITIONS REQUIREMENTS VALUE SETPotNT IMI l
- 14. Turbine Trip l
- b. Turbine Stop IIII 4 P SR 3.3.1.10 t 90% %.7%
open valve closure SR 3.3.1.14 open
- 15. Safety 1,2 2 trains o SR 3.3.1.13 NA NA Injection ($1) Input from Engineered Safety Feature I Actuation System l (ESFAS)
- 16. Reactor Trip System Interlocks
- a. Intermediate 2(d) 2 R SR 3.3.1.11 a 1.2E 5% 2.0E 5%
l Range Neutron SR 3.3.1.12 RTP RTP Flux, P-6
- b. Low Power 1 1 per S SR 3.3.1.5 Reactor Trips train NA NA Stock, P-7
P-9 l
P 10 and input to P 7 2 $ SR 3.3.1.10
- f. Turbine Inpulse 1 SR 3.3.1.12 s 12.3% 10% I Pressure, P 13 tapulse Inpulse Pressure Pressure Equivalent Equivalent turbine turbine (continued)
(d) Below the P 6 (Intermediate Range Neutron Flux) interlocks.
(j) Above the P-9 (Power Range Neutron Flux) interlock.
(t) For the P 10 input to P 7, the Allowable value is s 12.3% RTP and the Nominal Trip setpoint is 10% RTP.
(m) For the Power Range Neutron Flux, P 10, the Allowable Value is t 7.7% RTP and the Nominal Trip Setpoint is 10% RTP.
'(n) A channel is OPERA 8LE with an actual Trip Setpoint value outside its calibration tolerance band provided the Trip Setpoint value is conservative with respect to its associated Allowable Value and the cnannel is re-adjusted to within the established calibration tolerance. band of the Nominal Trip Setpoint. A Trip Setpoint may be set more conservative than the Nominal Trip Setpoint as necessary in response to plant conditions.
Vogtle Units 1 and 2 3.3-18 Amendment No. (Unit 1)
Amendment No. (Unit 2)
RTS Instrumentation 3.3.1 Table 3.3.1 1 (page 5 of 8)
Reactor Trip System instrumentation APPLICABLE MODES OR OTHER WOMINAL SPECIFIED REQUIRED SURVEILLANCE ALLOWASLE TRIP FUNCTION CONDITIONS CHANNELS CON 0lTIONS REQUIREMENTS VALUE SETPOINT IAI
- 14. Turbine Trip
- b. Turbine stop IIII 4 P SR 3.3.1.10 t 90% 96.7%
Valve Closure SR 3.3.1.14 open open
- 15. Safety 1,2 2 trains Q SR 3.3.1.13 NA NA Injection (SI) Input fros. Engineered Safety Feature Actuation System (ESFAS)
- 16. Reactor Trip System Interlocks
- a. Intermediate 2(d) 2 R SR 3.3.1.11 t 1.2E 5% 2.0E-5%
Range Neutron SR 3.3.1.12 RTP RTP Flux, P-6
- b. Low Power 1 1 per S SR 3.3.1.5 Reactor Trips train MA NA Block, P 7
to P 7 2 S SR 3.3.1.10 l
- f. Turbine inpulse 1 SR 3.3.1.12 s 12.3% 10% l Pressure, P 13 Impulse Inpulse 1 Pressure Pressure i Equivalent Equivalent turbine turbine (continued) j j (d) Below the P-6 (Intermediate Range Neutron Flux) interlocks.
(j) Above the P-9 (Power Range Neutron Flux) interlock.
(L) For the P 10 input to P-7, the Allowable value is s 12.3% RTP and the Nominal Trip setpoint is 10% RTP.
(m) For the Power Range Neutron Flux, P 10, the Allowable value is t 7.7% RTP and the Nominal Trip Setpoint is 10% RTP.
(n) A channel is OPERABLE with an actual Trip Setpoint value outside its calibration tolerance band provided the ,
Trip Setpoint value is conservative with respect to its associated Allowable value and the channet is re- i adjusted to within the established calibration tolerance band of the Nominal Trip Setpoint. A Trip Setpoint may be set more conservative than the Nominal Trip Setpoint as necessary in response to plant conditions.
Vogtle Units 1 and 2 3.3-18 Amendment No. (Unit 1)
Amendment No. (Unit 2) i
- .=
RTS instrumentation 3.3.1 Table 3.3.1 1 (page 5 of 8)
Reactor Trip System Instrunantation APPLICABLE MODES OR OTHER WONINAL SPECIFIED REQUIRED SURVEILLANCE ALLOWABLE TRIP FUNCTION CON 0lfl0NS CHANNELS CON 0!TIONS REQUIREMENTS VALUE SETPOINT(n) 14 Turbine Trip
- b. Turbine Stop 1(l) 4 P SR 3.3.1.10 t 90% 96.7%
Valve Closure SR 3.3.1.14 open open
- 15. Safety 1,2 2 trains 0 SR 3.3.1.13 NA NA Injection ($1) Input from Engineered Safety Feature Actuation System (ESFAS)
- 16. Reactor Trip System Interlocks
- a. Intermediate 2fd3 2 R SR 3.3.1.11 a 1.2E-5% 2.0E 5%
Range Weutron SR 3.3.1.12 RTP RTP Flux, P-6
- b. Low Power 1 1 per S SR 3.3.1.5 Reactor Trips train MA NA Block, P 7
P 10 and input to P 7 2 S SR 3.3.1.10
- f. Turbine I g ulse 1 SR 3.3.1.12 s 12.3% 10%
Pressure, P 13 Igulse impulse Pressure Pressure Equivalent Equivalent turbine turbine (continued)
.(d) Below the P 6 (Intermediate Range Neutron Flux) interlocks.
(j) Above the P 9 (Power Range Neutron Flux) interlock.
(l) For the P 10 input to P 7, the Allowable Value is 512.3% RTP and the Nominal Trip Setpoint is 10% RTP. l (m) For the Power Range Neutron Flux, P-10, the Allowable Value is t 7.7% RTP and the Nominal Trip Setpoint is 10% RTP.
.(n) A channel is OPERABLE with an actual Trip Setpoint value outside its calibration tolerance band provided the Trip Setpoint value is conservative with respect to its associated Allowable Value and the channel is re-adjusted to within the established calibration tolerance band of the Nominal Trip Setpoint. A Trip Setpoint may be set more conservative than the Nominal Trip Setpoint as necessary in response to plant conditions.
Vogtle Units 1 and 2 3.3-18 . Amendment No. (Unit 1)
Amendment No. (Unit 2)
. _ ._ _ . _ . _ . . _ . . _ . _ _ _ _ - _ _ _ _ _ _ . _ _ _ . _ _ _ . _ _ ~ .
l RTS Instrumentation B 3.3.1 1
BASES APPLICABLE 4. Intermediate Ranae Neutron Flux (continued)
SAFETY ANALYSES, LCO, and Above the P-10 setpoint, the Power Range Neutron- l APPLICABILITY Flux - High Setpoint trip and the Power Range Neutron Flux - High Positive Rate trip provide core protection for a rod withdrawal accident. In MODE 3, 4, or 5, the Intermediate Range Neutron Flux trip does not have ,
to be OPERABLE because the reactor cannot be started up in this condition. The core also has the required SDM to mitigate the consequences of a positive reactivity addition accident. In MODE 6, all rods are fully inserted and the core has a required increased SDM. Also, the NIS intermediate range indication is 1 typically low off-scale in this MODE. I
- 5. Source Ranae Neutron Flux The LCO requirement for the Source Range Neutron Flux l trip (NI-0031B, D, & E, NI-0032B, D, & G) Function ;
ensures that protection is provided against an l uncontrolled RCCA bank rod withdrawal accident from a subcritical condition during startup. This trip !
Function provides redundant protection to the Power l Range Neutron Flux - Low Setpoint and Intermediate Range Neutron Flux trip Functions. In MODES 3, 4, and 5, administrative controls also prevent the uncontrolled withdrawal of rods. The NIS source range detectors are located external to the reactor vessel 4 and measure neutrons leaking from the core. The NIS '
source range detectors do not provide any inputs to control systems. The source range trip is the only RTS automatic protection function required in MODES 3, 4, and 5. Therefore, the functional capability at the !
specified Trip Setpoint is assumed to be available.
The LC0 requires two channels of Source Range Neutron Flux to be OPERABLE. Two OPERABLE channels are sufficient to ensure no single random failure will disable this trip Function. The LC0 also requires two channels of the Source Range Neutron Flux to be OPERABLE in MODE 3, 4, or 5 with RTBs closed.
The Source Range Neutron Flux Function provides J protection for control rod withdrawal from j l
1 (continued) i Vogtle Units 1 and 2 B 3.3-13 Revision No.
i 4
-_r - -. - __ , _~ r ,,- . - - ,m. .,
RTS instrumentation B 3.3.1 i
BASES
, APPLICABLE 5. Source Ranae Neutron Flux (continued)
SAFETY ANALYSES,
'LCO, and subcritical, boron dilution (see LCO 3.3.8) and control rod ejection events. The Function also APPLICABILITY provides visual neutron flux indication in the control room.
In MODE 2 when below the P-6 setpoint during a reactor startup, the Source Range Neutron Flux trip must be OPERABLE. Above the P-6 setpoint, the Intermediate Range Neutron Flux trip and the Power Range Neutron Flux -- Low Setpoint trip will provide core protection for reactivity accidents. Above the P-6 setpoint, the Source Range Neutron Flux trip is blocked. l In MODE 3, 4, or 5 with the reactor shut down, the Source Range Neutron Flux trip Function must also be OPERABLE. If the Rod Control System is capable of rod withdrawal, the Source Range Neutron Flux trip must be OPERABLE to provide core protection against a rod withdrawal accident. If the Rod Control System is not capable of rod withdrawal, the source range detectors are not required to trip the reactor. Source range detectors also function to monitor for high flux at shutdown. This function is addressed in Specif' cation 3.3.8. Requirements for the source range detectors in H0DE 6 are addressed in LC0 3.9.3.
- 6. Overtemoerature AT The Overtemperature AI trip Function (TDI-0411C, TDI-04210, TDI-0431C, TDI-0441C, TDI-0411A, TDI-0421A, TDI-0431A, TDI-0441A) is provided to ensure that the design limit DNBR is met. This trip Function also limits the range over which the Overpower oT trip Function must provide protection. The inputs to the Overtemperature oT trip include pressure, coolant .
temperature, axial power distribution, and reactor power as indicated by loop AI assuming full reactor coolant flow. Protection from violating the DNBR limit is assured for those transients that are slow with respect to delays.from the core to the measurement system. The Function monitors both variation in power and flow since a decrease in flow (continued)
Vogtle Units 1 and 2 8 3.3-14 Revision No.
RTS Instrumentation B 3.3.1 BASES APPLICABLE 16. Reactor Trio System Interlocks SAFETY ANALYSES, LCO, and Reactor protection interlocks are provided to ensure APPLICABILITY reactor trips are in the correct configuration for the (continued) current unit status. They back up operator actions to ensure protection system Functions are not bypassed during unit conditions under which the safety analysis assumes the Functions are not bypassed. Therefore, the interlock Functions do not need to be OPERABLE when the associated reactor trip functions are outside the applicable MODES. These are:
- a. Intermediate Ranae Neutron Flux. P-6 The Intermediate Range Neutron Flux, P-6 interlock (NI-0035B, D, & E, NI-00368, D, & G) is actuated when any NIS intermediate range channel goes approximately one decade above the minimum channel reading. If both channels drop below the setpoint, the permissive will automatically be defeated. The LCO requirement for the P-6 interlock ensures that the following Functions are performed:
- on increasing power, the P-6 interlock allows the manual block of the NIS Source Range, Neutron Flux reactor trip. This prevents a premature block of the source range trip and allows the operator to ensure that the intermediate range is OPERABLE prior to leaving the source range.
I
- on decreasing power, the P-6 interlock automatically enables the NIS Source Range l Neutron Flux reactor trip.
The LC0 requires two channels of Intermediate Range Neutron Flux, P-6 interlock to be OPERABLE in MODE 2 when below the P-6 interlock setpoint.
(continued)
Vogtle Units 1 and 2 B 3.3-29 Revision No.
RTS Instrumentation B 3.3.1 BASES APPLICABLE d. Power Ranae Neutron Flux. P-9 (continued)
SAFETY ANALYSES, LCO, and reactor is not at a power level sufficient to APPLICABILITY have a load rejection beyond the capacity of the Steam Dump System.
- e. Power Ranae Neutron Flux. P-10 The Power Range Neutron Flux, P-10 interlock (NI-00418 & C, NI-0042B & C, NI-0043B & C, NI-0044B & C) is actuated at approximately 10%
power, as determined by two-out-of-four NIS power range detectors. If power level falls below 10% RTP on 3 of 4 channels, the nuclear instrument trips will be automatically unblocked.
The LC0 requirement for the P-10 interlock ensures that the following Functions are performed:
- on increasing power, the P-10 interlock allows the operator to manually block the Intermediate Range Neutron Flux reactor trip. Note that blocking the reactor trip also blocks the signal to prevent automatic and manual rod withdrawal;
- on increasing power, the P-10 interlock allows the operator to manually block the Power Range Neutron Flux -- Low reactor trip;
- on increasing power, the P-10 interlock automatically provides a backup signal to block the Source Range Neutron Flux reactor trip;. l
- the P-10 interlock provides one of the two inputs to the P-7 interlock; and
- on decreasing power, the P-10 interlock automatically enables the Power Range Neutron Flux -- Low reactor trip and the Intermediate Range Neutron Flux reactor trip (and rod stop).
(continued)
Vogtle Units 1 and 2 B 3.3-33 Revision No.
u__ .
RTS Instrumentation B 3.3.1 BASES
. SURVEILLANCE SR 3.3.1.10
' REQUIREMENTS (continued) A CHANNEL CALIBRATION is performed every 18 months, or approximately at every refueling. CHANNEL CALIBRATION is a complete check of the instrument loop, including the sensor.
The test verifies that the channel responds to a measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATIONS must be performed consistent with the assumptions of the unit specific setpoint methodology. The difference between the current "as found" values and the previous test "as left" values must be consistent with the drift allowance used in the setpoint methodology.
The Frequency of 18 months is based on the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint methodology for some instrument functions, and the need to perform this
' Surveillance for some instrument functions under the conditions that apply during a plant outage and the potential for an unplanned plant transient if the Surveillance were performed at power. Operating experience has shown these components usually pass the Surveillance when performed on the 18 month Frequency.
SR 3.3.1.10 is modified by a Note stating that this test shall include verification that the time constants are adjusted to the prescribed values where applicable.
SR 3.3.1.11 SR 3.3.1.11 is the performance of a CHANNEL CALIBRATION, as described in SR 3.3.1.10, every 18 months. This SR is modified by a Note that states that neutron detectors are excluded from the CHANNEL CALIBRATION. The CHANNEL CALIBRATION for the power range neutron detectors includes a normalization of the detectors based on a power calorimetric and flux map performed above 75% RTP. The CHANNEL CALIBRATION for the source range neutron detectors includes obtaining the detector preamp discriminator curves and evaluating those curves.
(continued)
Vogtle Units I and 2 B 3.3-56 Revision No.
RTS Instrumentation B 3.3.1 BASES SURVEILLANCE SR 3.3.1.11 (continued) -
REQUIREMENTS The 18 month Frequency is based on the need to perform this l Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown these components usually pass the Surveillance when performed on the 18 month Frequency.
SR 3.3.1.12 SR 3.3.1.12 is the performance of a COT of RTS interlocks every 18 months.
The Frequency is based on the known reliability of the interlocks and the multichannel redundancy available, and has been shown to be acceptable through operating experience.
SR 3.3.1.13 SR 3.3.1.13 is the performance of a TAD 0T of the Manual Reactor Trip and the SI Input from ESFAS. This TADOT is as described in SR 3.3.1.4, except that the test is performed every 18 months.
The manual reactor trip TADOT shall independently verify the OPERABILITY of the undervoltage and shunt trip circuits for the manual reactor trip function. This test shall also ,
verify the OPERABILITY of the Bypass breaker trip !
circuit (s), including the automatic undervoltage trip.
The Frequency is based on the known reliability of the Functions and the multichannel redundancy available, and has been shown to be acceptable through operating experience.
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(continued)
Vogtle Units 1 and 2 B 3.3-57 Revision No.
HFASA Instrumentation B 3.3.8 B 3.3 INSTRUMENTATION B 3.3.8 High Flux at Shutdown Alarm (HFASA)
BASES BACKGROUND The' primary purpose of the HFASA is to warn the operator of an unplanned boron dilution event in sufficient time (15 minutes prior to loss of shutdown margin) to allow manual action to terminate the event. The HFASA is used for this purpose in MODES 3 and 4, and MODE 5 with tha loops filled.
The HFASA consists of two channels of alarms, with each channel receiving input from one source range channel. An alarm setpoint of s 2.3 times background provides at least l 15 minutes from the time the HFASA occurs to the total loss of shutdown margin due to an unplanned dilution event. This meets the Standard Review Plan criteria for mitigating the ;
consequences of an unplanned dilution event by relying on l operator action.
APPLICABLE The analysis presented in Reference 1 identifies credible '
SAFETY ANALYSES boron dilutian ' initiators. Time intervals from the HFASA until loss of shutdown margin were calculated. The results demonstrate that sufficient time for operator response is available to terminate an inadvertent dilution event taking credit for one HFASA with a setpoint of s 2.3 times l l background.
The HFASA satisfied Criterion 3 of the NRC Policy Statement.
LC0 The LCO requires two channels of HFASA to be OPERABLE with input from two source range channels to provide protection against single failure.
APPLICABILITY The HFASA must be OPERABLE in MODES 3, 4, and 5.
The Applicability is modified by a Note which allows the HFASA to be blocked in MODE 3 during reactor startup so that spurious alarms are not generated.
(continued)
Vogtle Units 1 and 2 B 3.3-171 Revision No.
. . _ . _ . - - _ _ _ . - _ . _ . -..m_-.__._.___._.. . . _ _ _ _ _ . _ _ _ _ . _ . _ . _
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Nuclear Instrumentation i N B 3.9.3 8 3.9 REFUELING OPERATIONS B 3.9.3 Nuclear. Instrumentation
. BASES BACKGROUND The source range neutron flux monitors are used during refueling operations to monitor the core reactivity
. condition. The installed source range neutron flux monitors (NI-0031.and NI-0032) are part of the Nuclear
. Instrumentation System (NIS). These detectors are located external to the reactor vessel and detect neutrons leaking from the core. Temporary neutron flux detectors which l- provide equivalent indication may be utilized in place of installed instrumentation.
)
The installed source range. neutron flux monitors are fission 4 chamber detectors. The detectors monitor the neutron flux in L counts per second. The instrument range covers seven decades of neutron flux (IE-leps to IE+6 cps) with a 2%
l ;
instrument accuracy. The detectors also provide continuous i visual indication in the control room. The NIS is designed in accordance'with the cr'? ria presented in Reference 1.
l
, i APPLICABLE Two OPERABLE source range neutron flux monitors are required ;
-SAFETY ANALYSES- to provide a signal, to alert the operator to unexpected changes in core reactivity such as an improperly loaded fuel assembly. ;The need for a safety analysis for an !
uncontrolled boron dilution. accident is minimized by isolating all unborated water sources except'as provided for by LCO 3.9.2, "Unborated Water' Source Isolation Valves."
The source range neutron flux monitors satisfy Criterion 3 of the NRC Policy Statement.
LC0 This LCO requires that two source range neutron flux monitors be OPERABLE to ensure that redundant monitoring capability is available to detect changes in core reactivity. To be OPERABLE each monitor must provide visual indication.
(continued)
'Vogtle' Units 'I and 2 B 3.9-9 Revision No.
. . .-- _. -- -.. . _ . _ . . . - . - . .- -. .- _ . - - - . .... . - . - ~
l Nuclear Instrumentation l B 3.9.3 J BASES
-ACTIONS H21 (continued)~
are OPERABLE. This stabilized condition is determined by performing SR 3.9.1.1 to ensure that the required boron i concentration exists. l The Completion Time of once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient to obtain and analyze a reactor coolant sample for boron <
concentration and to ensure that unplanned changes in boron 1 concentration would be identified. The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion i Time is reasonable, considering the low probability of a change in core reactivity during this time period.
SURVEILLANCE SR 3.9.3.1 1 REQUIREMENTS SR 3.9.3.1 is the performance of a CHANNEL CHECK, which is a comparison of the parameter indicated on one channel to a similar parameter on other channels. It is based on the assumption that the two indication channels should be consistent with core conditions. Changes in fuel loading and core geometry can result in significant differences between source range channels, but each channel should be consistent with its local conditions.
The Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is consistent with the CHANNEL CHECK Frequency specified similarly for the same instruments in LC0 3.3.1, " Reactor Trip System (RTS) Instrumentation."
SR 3.9.3.2 SR 3.9.3.2 is the performance of a CHANNEL CALIBRATION every 18 months. This SR is modified by a Note stating that neutron ~ detectors are excluded from the CHANNEL CALIBRATION.
The CHANNEL CALIBRATION for the source range neutron flux monitors includes obtaining the detector preamp l discriminator curves and evaluating those curves. The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage. Operating experience has shown these components I
usually pass the Surveillance when performed at the 18 month i
Frequency.
h L
(continued)
B 3.9-11 Revision No, Vogtle Units 1 and 2 t
.