Text

Proposed Tech Specs Re ESFAS Instrumentation
	ML20073S805
Person / Time
Site:	Millstone
Issue date:	07/01/1994
From:	; NORTHEAST NUCLEAR ENERGY CO.
To:	;
Shared Package
ML20073S804	List: B14788, Application for Amend to License DPR-65,revising TS Re ESFAS Instrumentaion; ML20073S805;
References
	NUDOCS 9407060230
	Download: ML20073S805 (18)
	v • d • e

. . . .

Docket No. 50-336 B14788 I

d Attachment 2

Millstone Nuclear Power Station, Unit No. 2 Proposed Revision to Technical Specifications Engineered Safety Feature Actuation System Instrumentation Marked-Up Pages l

l l

P c

t i

July 1994 l

9407060230 940701 PDR ADOCK 05000036 P PDR ;

IABLE 3.3 - . Continued) t

. -e ENGINEERED _ SAFETY FEATURE' ACTUATION SYSTEN INSTRUNENTATION -

35 MININUN ;

$ TOTAL NO. CHANNELS CHANNELS APPLICABLE 3 , FUNCTIONAL UNIT OF CHANNELS TO TRIP OPERABLE NODES ACTION t

m l

4. MAIN STEAM LINE , ._ /- <

$ pr s k (Rr 077zws 2- / 2 I' E' 1 Y 'h

[(- P5ssure r ^ ~ Y 1M

~

. [ M ontainment Hign 2 2 i

'E. Steam Generator

(- .

Pressure - Low 4 2 3 -

1,2,3(c) 2 S. ENCLOSURE BUILDING fit.TRATION (EBFAS) w a. Manual ' EBFAS (Trip 2 1 2 1, 7, 3, 4 1

} Buttons) 5 w

b. Manual SIAS (Trip 2 .1 2- 1, 2, 3, 4 I Buttons)

c. Containment Pressure-Hfgh 4 2 3 1, 2,.3 2 l

d. Pressurizer Pressure-Low 4 2 3 1,2,3(a) 2

6. CONTA!PetENT-SUMP RECIRCULATION (SRAS) k a. Manual SRAS (Trip

a Buttons) 2 1 2 1, 2, 3, 4 1 t i

g i S b. Refueling yater Storage f'

?

Tank - Low 4 2[ f3 \) 1. 2, 3 4 [>

l m %M E,l

g; -

I 'I L . ;<

1 l R

.l 4

veceioet ca, 63,4 r

TABLE 3.3-3 (Continued) ,

TABLE NOTATION ,

(a) Trip function may be bypassed when pressurizer pressure is < 1750 psia; bypass shall be automatically removed when pressurizer pressure is 11750 psia.

(b) An SIAS signal is first necessary to enable CSAS logic.

(c) Trip function may be. bypassed below 600 psia; bypass shall be automatically removed at or above 600 psia.

(d) Each channel has two sensors, high radiation level on either sensor will initiate containment purge valve isolation.

(e) Trip may be bypassed during testing pursuant to Special Test Exception 3.10.3.

(f)jklejF335Eiiattens--ef .^/C and B/D do not_prm.ide_LSRAS_itip-cond44 ton. }

ACTION STATEMENTS l ACTION 1 - With the number of OPERABLE channels one less than the Total Number of Channels, restore the inoperable channel to OPERA 3LE status within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months ..

ACTION 2 - With the number of OPERABLE channels one less than the Total

< Number of Channels and with the pressurizer pressure:

L

a. < 1750 psia; immediately place the inoperable channel in the

bypassed condition; restore the inoperable channel to OPERABLE status prior to increasing the pressurizer pressure above 1750 psia.

l b. 21750 psia, operation may continue with the inoperable channel in the bypassed condition, provided the following-

, conditions are satisfied:

l. All functional units receiving an input from the bypassed channel are also pla~ced in the bypassed condition.

2. The Minimum Channels OPERABLE requirement is met; however, one additional channel may be removed from service for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing per Specificatire 4.3.2.1 provided one of the inoperable channels is placed in the tripped condition.

L MILLSTONE - UNIT 2 3/4 3-16 Amendment' No. 168 con 4

.* .. t.:..

Decembar 23, 19

,)

TABLE 3.3 3 (Continuedt

( ACTION 3 - With che er more channels inoperable, operation may continue provided the containment purge valves are maintained closed.-

x, - m~ W ACTION 4 - W1 the ber 0PERABLF/ channels e less t an the Mi mum t r Chan s, plac ;he inoper le chan in the passed .

channel OPERABL status w min ondi on and estore

- 48 h rs or in COLP HUTDOWN thin the ext 36 ho s. No

- et r cha els sha1Voe remove from serv #ce for su eillance t sting ring this' ACTION STATEMENT.

I .

A With the number of OPERABLE channels one less than the Total

$8 IL p Number of Channels and with the pressurizer pressure: i N a. < 1750 psia: ismediately place the inoperable channel in

,,pd the bypassed condition; restore the inoperable channel to iv OPERABLE status prior to increasing the pressurizer T,l pressure above 1750 psia,

b. 1 1750 psia, operation may continue with the inoperable k channel in the bypassed condition, provided the following ,

condition is satisfied:

( 1. The Minimum Channels OPERABLE requirement is met; s however, one additional channel may be removed from service for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing per Specification 4.3.2.1 provided &QIti of the inoperable channels are placed in the bypassed condition.

1

(

g510NE-UNIT 2 3/4 3-17 Amendment No. 168

__-_ - _________ _ ]

.x TABLE 3.3-4 . .

" i -

"0; TE lfEER S_ SAFETY FEATURE ACTUATION SYSTEd INSTRUNENTATION TRIP VALUES .

-4 E

i 7 ALLOWA8tE TRIP.SETPOINT VALUES g FUNCTIONAL UNIT

1. SAFETY INJECTION (SIAS)

a. Manual (Trip Buttcns) Not Applicable t App 1Icable

b. Containment Pressure - High 4.75 psig 1 5.20 psig -

c. Pressurizer Pressure - Low 1 1600 psia 1 1592.5 psia l

, 2. CONTAINNENT SPRAY (CSAS) ,

a. Manual (Trip Buttons) Not Applicable Not Applicable '

b. Containment Pressure -- High-High 1 9.48 psig i 10.11 psig

}

Y 3. CONTAINNENT ISOLATION (CIAS)

a. Manual CIAS'(Trip Buttons) Not Applicable Not Applicable

b. Manual SIAS (Trip Buttons) Not Applicable Not Applicable

c. Containment Pressure - High 1 4.75 psig 1 5.20 psig' i

d. Pressurizer Pressure - Low 1 1600 psia 1 1592.5 psia

4. NAIN STEAM LINE_150LATION _

- ~~ /'-m'~-~~'-m 7 /, g /,,, [/

iK 9 47 5' #E E b )

1 500 psia 1 492.5 psia g c, f. Steam Generator Pressure - Low

{!

B' -

i

. g ,

, i g i<

, e ,;

i E

u i 3

TABLE *.3-2 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS

z CHANNEL MODES IN UNICH '

E CHANNEL CHANNEL FUNCTIONAL SUPTEILLANCE CAllBRATION TEST RLOUIRED

~3 FUNCTIONAL UNIT CHECK __

a m 1. SAFETY INJECTION (SIAS)

. a. Manual (Trip Buttons) N.A. N.A. R N. A.

Containment Pressure - High R M 1, 2, 3 c b. S 5 M 1, 2, 3

c. Pressurizer Pressure - Low S R 1,i 2, 3

[. d. , Automatic Actuation Logic N.A. N.A. M(1)

2. CONTAIMENT SPRAY (CSAS)

a. Manual (Trip Buttons) N.A. M.A. R M.A.

b. Containment Pressure--

M 1, 2, 3 High - High S R

c. Automatic Actuation Logic M.A. N.A. M(1) 1, 2, 3

3. CONTAlWENT ISOLATION (CIAS)

a. Manual CIAS (Trip Buttons) N.A. N.A. R N.A.

, M.A.

N b. Manual SIAS (Trip Buttons) N.A. M.A. R

Containment Pressure - High R M 1, ?, 3

, c. S

d. Pressurizer Pressure - Low S R M 1, 1, 3 g,

w e. Automatic Actuation Logic _ -m N.A. N.A. M(I) I, 2, 3 f f - ~_.m_ ,

^4- 6

, /.D

4. MAIN STEAM LINE ISOLATION / $ 7 Al b s N T " M' v l', 2, 3 '

) W.'

c / [ Containment Steam Generator Pressure Pressure -M-- Low1g hSi R M 1, 2, 3 M.A. N.A. M(1) 1, 2, 3 i g, ,c ) Automatic Actuation Logic

5. ENCLOSURE BUILDING FILTRATION (EBFAS)

a. Manual EBFAS (Trip Buttons) N.A. M.A. R N.A.

N.A. N.A. R N.A.

y b. Manual SIAS (Trip Buttons)

M 1, 2, 3 e

g c. Containment Pressure - High 5 R R M 1, 2, 3 g a d. Pressurizer Pressura - Low S tQ

e. Automatic Actuation Logic M.A. N.A. M(1) 1, 2, 3 8 O

1 E

t .

~

I

- - - - - - _ - _ _ _ - - -- ,y =,7 4 w. y,

, mf % 3p r f~N '

[ %

INSTRUMENTATION W ENGINEERED SAFETY FEATURE ACTUATION SYSTEN SENSOR CABINET POWER SUPPLY DRAWERS

((J

/

t

! LIMITING CONDITION FOR OPERATION 3.3.2.2 The engineered safety feature actuation system Sensor Cabinets (RCO2A1, RC02B2, RCO2C3 & RC02D4) Power Su) ply Drawers shall be OPERABLE and energized from the normal power source wit 1 the backup power source available.

The normal and backup power sources for each sensor cabinet is detailed in Table 3.3-Sa:

CABINET NORMAL POWER BACKUP POWER s RC02Al VA-10 VA-40 i i

RC02B2 VA-20 VA-30 RC02C3 VA-30 _ VA-20

/ RC0204 VA-40 VA-10 {

Table 3.3-Sa l

$PPLICABILITY: MODES 1, 2, 3 and 4 (

ACTION:

l

/ With any of the Sensor Cabinet Power Supply Drawers inoperable, or either the normal or backup power source not available as delineated in Table 3.3-5a,

. restore the inoperable Sensor Cabinet Power Supply Drawer to OPERABLE status .\

within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . N SURVEILLANCE REQUIREMENTS I \

/ \

I 4.3.2.2.1 The engineered safety feature actuation system Sensor Cabinet Power >

i Supply Drawers shall be determined OPERABLE once per shift by visual l inspection of the power supply drawer indicating lamps.

4.3.2.2.2 Verify the operability of the Sensor Cabinet Power Supply !

\

auctioneering circuit at least one per 18 months. -[

\

)

\

G -

MILLSTONE - UNIT 2 3/4 3-25a Amendment No.

0131

INSTRUMENTATION BASES 2/4.3.1 AND 3/4.3.2 PROTECTIVE AND ENGINEERED SAFETY 7EATURES (ESF1 INSTRUMENTATION (Continued)

The maximum allowable trip value for these monitors corresponds to calculated concentrations at the site boundary which would not exceed the concentrations listed in 10 CFR Part 20, Appendix B Table II. Exposure for a year to the concentrations in 10 CFR Part 20, Appendix B. Table corresponds to a total body sose to an individual of 500 mrem which is well below the guioelines of 10 CFR Part 100 for an individual at any point on the exclusion area boundary for two hours.

Determination of the. monitor's trip value in counts per minute, which is the actual instrument response, involves several factors including: 1) the atmospheric dispersion (x/Q), 2) isotopic composition of the sample, 3) sample flow rate, 4) sample collection efficiency, 5) counting efficiency, and 6)3the background radiation level at the detector. The x/Q of Ss8 x 10-6 sec/m is the highest annual average x/Q estimated for the site boundary (0.g mileg in the NE sector) for vent releases from the containment and 7.5 x 10 sec/m is the nighest annual average x/Q estimated for an off-site location (3 miles in the NNE sector) for releases from the Unit I stack. This calculation also assumes that the isotopic composition is xenon-133 for gaseous radioactivity and cesium-137 for partieglate radioactivity (Half Lives greater than 8 days).

The. upper limit of 5 x 10 cpm is approximately 90 percent

of full instrument

-s^ w

\ scale'.

175247' p: W

{.

3703'NORTTI) RING INSTRUMENTAUd

^ - ~ W'% F ) -

3/4.3.3.1 RADIATION MONITORING INSTRUMENTATION The OPERABILITY of the radiation monitoring channels ensures that 1) the radini~on levels are continually measured in the areas served by the individual channels and 2) the alarm or rutomatic action is initiated when the radiation level trip setpoint is exceeded.

The spent fuel storage area monitors provide a signal to direct the l ventilation exhaust from the spent fuel storage area through a filter train '

when the dose rate exceeds the setpoint. The filter train is provided to reduce the particulate and iodine radioactivity released ta the atmosphere.

Should an accident involving spent fuel occur, the 100 mR/hr actuation setpoint would be sufficient to limit any consequences at the exclusion area boundary to those evaluated in the NRC Safety Evaluation, Section 15 (May 1974).

" HISTONE - UNIT 2 E 3/4 3-2 Amendment No.157

4 Add to 3/4.3 Instrumentatipa Bases SRAS Locio Modification Action Statement 4 of Table 3.3-3, which applies only to the SRAS logic, specifies that during surveillance testing, the second inoperable channel must also be placed in the bypassed condition.

For the SRAS logic, placing the second inoperable channel in the tripped condition (as in Action Statement 2) could result in the false generation of a SRAS signal due to an additional failure which causes a trip signal in either of the remaining channels at the onset of a LOCA. The false generation of the SRAS signal leads to unacceptable consequences for LOCA mitigation.

With Action Statement 4, during the two hour period when two channels are bypassed, no additional failure can result in the false generation of the SRAS signal. However, an additional failure that prevents a trip of either of the two remaining channels may prevent the generation of a true SRAS signal while in this Action Statement. If no SRAS is gener.ted at the appropriate time- operating procedures instrt:vt the operator to ensure that the SRAS actuation occurs when tne refueling water storage tank level decreases. Due to the limited period of vulnerability, and the existence of operator requirements to manually initiate an SRAS if an automatic initiation does not occur, this risk is considered acceptable.

Sensor Cabinet Power SUDDiv Auctioneerinc a

The auctioneering circuit of the ESFAS sensor cabinets ensures that two sensor cabinets do not de-energize upon loss of a D.C.

bus thereby resulting in the false generation of an SRAS. Power source VA-10 provides normal power to sensor cabinet A and backup power to sensor cabinet D. VA-40 provides normal power to sensor cabinet D and backup power to cabinet A. Power sources VA-20 and VA-30 and sensor cabinets B and C are similarly arranced.

If the normal or backup power source for an ESFAS Sensor Cabine?.

is lost, two sensor cabinets would be supplied from the same power source, but would still be operating with no subsequent trip signals present. However, any additional failure associated with this power source would result in the loss of the two sensor cabinets, consequently generating a false SRAS. The 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months Action Statement ensures that the probability of a LOCA and an additional failure of the remaining power cource, while in this Action Statement is sufficiently small.

Docket No. 50-336 B14788 Attachment 3 Millstone Nuclear Power Station, Unit.No. 2

' Proposed Revision to Technical Specifications Engineered Safety Feature Actuation. System Instrumentation-Retyped Pages July 1994

e-TABLE 3.3-3 (Ccntinued)

~

ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION

$5 MINIMUM

E TOTAL NO. CHANNELS CHANNELS- APPLICABLE y FUNCTIONAL UNIT OF CHANNELS TO TRIP OPERABLE MODES ACTION z

4. MAIN STEAM LINE ISOLATION h

z Z a. Manual MSI (Trip Buttons) 2 1 2 1, 2, 3, 4 1 to 2 3 1, 2, 3 2

b. Containment Pressure - 4 High

c. Steam Generator Pressure - Low 4 2 3 1,2,3(c) 2

5. ENCLOSURE BUILDING FILT?1 TION (EBFAS)

a. Manual EBFAS (Trip 2 1 2 1,2,3,4 I w Buttons)

b. Manual' SIAS (Trip- 2 1 2 1, 2, 3, 4 1 Buttons)

c. Containment Pressure-High 4 2 3 1, 2, 3 2 1

d. Pressurizer Pressure- i Low 4 2 3. 1,2,3(a) 2 l

6. CONTAINMENT SUMP E RECIRCULATION (SRAS)

E E a.. Manual SRAS (Trip Buttons) 2 1 2 1,2,3,4 1 g

N

~

b. Refueling Water Storage' 2 3 1, 2, 3 4 "g Tank - Low 4: l

-. .a.- - - - . - - ' - . . - - --....-..- - - . -

- .....I

..-.iw m- - . . .. .- ,.=o i- -.

. +--i--.-..----.-

...z-- , - . --- - - -- ..--.i.- .

_ _ _ _ _ . _ . , , . . . . . . . .. ,..i-

- .. .- n... . - - - --. .. . .. - -. . . .__. .

, ,c- o l

TABLE 3.3-3 (Continued)

, TABLE NOTATION <

l (a) Trip function may be_typassed when pressurizer pressure is < 1750 psia; i

bypass shall be automatically removed when pressurizer pressure is 11750 psia.

l

, (b) An SIAS signal is first necessary to enable CSAS logic.

4 (c) Trip function may be bypassed below 600 psia; bypass shall be

automatically removed at or above-600 piia.

i l

(d) Each channel has wo sensors, high radiation level on either sensor will initiate containment purge valve isolation.

(e) Trip may be bypassed during testing pursuant to Special Test Exception 3.10.3.

I ACTION STATEMENTS i

ACTION 1 - With the number of OPERABLE channels one less than ine Total Number of Channels, restore the inoperable chano6 to OPERABLE status within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months or be in r0LD SP.UTbum within the next 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

{_ ACTION 2 - With the number of OPERAbil channels one leis than the Total j Number of Channels and with the pressurizer pressure:

l a. < 1750 psia; immediately place the inoperable channel in

,-- the bypassed condition;-. restore the inoperable channel to l OPERABLE status prior to increasing _the pressurizer l pressure above 1750 psia.

b. 21750 psia, oparation may continue with the inoperable

channel in the bypassed condition, provided the following l conditions are satisfied:

i

l. All functional units receiving an input from the l bypassed channel are also placed in the bypassed

condition.

2. The Minimum Channels OPERABLE requirement is met; 4

l however, one additional channel may be removed from service for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing per Specification 4.3. 1 provided one of tne inoperable channels is placed in the tripped condf' ion.

l

! MILLSTONE - UNIT 2 3/4 3-16 Amendment No. JJp, 3 0129 l

TABLE 3.3-3 (Continuedl ACTION 3 - With one or more channels inoperable, operation may continue provided the containment purge valves are maintained closed.

ACTION 4 - With the number of OPERABLE channels one less tt.an the Total Number of Channels and with the pressurizer pressure:

a. < 1750 psia: immediately place the inoperable channel in the bypassed condition; restore the inoperable channel to OPERABLE status prior to increasing the pressurizer pressure above 1750 psia.

b. 11750 psia, operation may continue with the inoperable channel in the bypassed condition, provided the following condition is satisfied:

1. The Minimum Channels OPERABLE requirement is met; however, one additional channel may be removed from service for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months for surveillance testing per Specification 4.3.2.1 provided HQIB of the inoperable channels are placed in the bypassed condition.

4 MILLSTONE - UNIT 2 3/4 3-17 Amendment No. JJ7, 0129

se C

-l 2ABLE 3.3-4 ,

25 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP VALUES sp -

y ALLOWABLE E FUNCTIONAL UNIT TRIP SETPOINT _ VALUES _

m

l. SAFETY INJECTION (SIAS) g a. Manual (Trip Buttons) Not Applicable Not ApplicaDie Z 5 5.20 psig m b. Containment Pressure - High 4.75 psig

c. Pressurifer Pressure Iow 2 1600 psia 1 1592.5 psia i

2. CONTAINMENT SPRAY (CSAS)

a. Manual (Trip Buttons) Not Applicable Not Applicable

b. Containment Pressure -- Higa :igh 5 9.48 psig . s 10.11 psig R 3. -CONTAINMENT ISOLATION (CIAS)

a. Manual CIAS (Trip Buttons) Not Applicable Not Applicable

[

1 Ei' b. Manual SIAS (Trip Buttons) Not Applicable Not Applicable

c. Containment Pressure - High s 4.75 psig s 5.20 psig

d. Pressurizer Pressure - Low 1 1600 psia 2 1592.5 psia

4. MAIN STEAM LINE ISOLATION

a. Manual (Trip Buttons) Not Applicable Not Applic61e k b. Containment Pressure - High 5 4.75 psig 1 5.20 pric

c. Steam Generator Pressure - Low 1 500 psia 2 492.5 psia E

E i

v y i

- v n.

."-fdf_4,3-2 ex ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION SURVEILLANCE RE0VIREMEN71

$P CHANNEL m) DES IN WHICH G FUCTIONAL SURVEILLANCE

$ CHANNEL CH/JINEL TEST REQUIRED N FUNCTIONAL UNII CHECK CALIBRATIO_ti e 1. SAFETY' INJECTION (SIAS)- !!

Manual (Trip Buttons)- N.A. N.A. R A.

5 a.

h 1, 2, 3

b. Containment Pre'ssure - 91gh S R H 1, 2, 3

c. Pressurizer Pressure - Lew S R 1, 2, 3

d. Automatic Actuation Logic N.A. N.A. M(1)

'2. CONT?.INMENT SPRAY (CSAS)

a. Manual (Trip Buttons) N.A. N.A. R N.A.

b. Containment Pressure--

M 1, 2, 3

.High - High .S R N.A. 1, 2, 3

c. Automatic Actuation Logic N.A. M(1)

R .3. CONTAINMENT ISOLATION (CIAS)

N.A. N.A. N.A.

a. Manual CIAS (Trip Buttons) R

b. Manu ' SIAS (Trip Buttons) N.A. N.A. R N.A.

Y 1, 2, 3 O c. Containment Pressure - High S R M M 1, 2, 3

d. Pressurizer: Pressure - Low S R Automatic Actuation Logic N.A. N.A. M(1) I, 2, 3 e.

4. MAIN STEAM LINE ISOLATION N.A. N.A. R N.A.

a.. Manu::1 (Trip Buttons): 1, 2, 3

b. Containment Pressure - High- S R M

'S R M 1, 2, 3

c. Steam Generator Pressure - Low .

d. Automatic Actuation Logic N.A. N.A. M(1) I, 2, 3 t

k 5. ENCLOSURE' BUILDING FILTRATION (EBFAS)

N.A. N.A. N.A.

a a.- Manual EBFAS (Trip Buttons) R

b. Manual SIAS (Trip Buttons) N.A. N.A. R N.A.

5 1, 2, 3 S c. Containment Pressure - High .S R M 1, 2, 3

d. Pressurizer Pressure - Low .S R M z 2,- 3

. e. Automatic Actuation Logic N.A. N.A. M(1) I, 4

?

w_ __ -

~

INSTRUNENTATION fMINEERED SAFETY FEATURE At:TUATION SYSTEN SENSOR CAIJJfEI POWER SUPPLY DRAWERS LIK. TING CONDITION FOR OPERATION 3.3.2.2 The engineered safety feature actuation system Sansor Cabinets (RCO2Al, RCO2B2, RC02C3 & RC0204) Power Su) ply Drawers shall be OPERABLE and energized from the normal power source witi the backuo power source available.

The normal and backup power sources for each sensor cabinet is detailed in Table 3.3 Sa:

CABINET- NORMAL POWER BACKUP POWER RCO2Al VA 10 VA-40 RCO2B2 VA-20 VA-30 RC02C3 VA-30 VA-20 RC0204 VA 40 _VA 10 Table 3.3-5a APPLICADILITY: MODES 1, 2, 3 and 4 ACTION:

With any of the Sensor Cabinet Power Sup)1y Drawers inoperable, or either the normal or backup power source not availa)le as delineated in Table 3.3-Sa, restore the inoperable Sensor Cabinet Power Sup)1y Drawer to OPERABLE status

(

within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months or be in COLD SHUTDOWN within tie next 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

SURVEILLANCE REQUIRENENTS 4.3.2.2.1 The engineered safety feature actuation system Sensor Cabinet Power Supply Drawers shall be determined OPERABLE once per shift by visual-inspection of the power supply drawer indicating lamps.

4.3.2.2.2 Verify the operability of the Sensor Cabinet Power Supply auctioneering circuit at least one per 18 it.anths. !

'l NILLSTONE - UNIT 2 3/4 3-25a Amendment No.

0131

.a ,-

l

]

INSTRUMENTAllM l

j BASES l !

I I j 2/4.3.1 AND 3/4.3.2 PROTECTIVE AND ENGINEEREQ SAFETY FEATURES (ESF) !

INSTRUMENTATION (Continued) ,

l The maximum allowable trip value for these monitors corresponds to j calculated concentrations at the site boundary which would not exceed the l concentrations listed in_10 CFR Part 20, Appendix B, Table II. Exposure for a >

! year to the concentrations in 10 CFR Part 20 Appendix 8. Table corresponds to i a total body dose to an individual of 500 mrem which is well below the guidelines '

i of 10 CFR Part 100 for an individual at any point on the exclusion area boundary ,

i for two hours, f

! Determination of the monitor's trip value in counts per minute, which is !

. the actual instrument response, involves several factors including: 1) the

atmospheric dispersion (x/Q), 2) isotopic composition of the sample, 3) sample

flow rate, 4) sample collection efficiency, 5) counting efficiency,4and 6)'the, background radiation level at the detector. The x/Q of 5.8 x 10 sec/m is i the highast annual average x/Q estimated for the site boundary (0.48 miles in the NE se or) for vent releases from the containment and 7.5 x 10* sec/m* is j the highest annual average x/Q estimated for an off-site location (3 miles in

the NNE sector) for releases from the Unit I stack. This calculation also i

assumes that the isotopic composition is xenon-133 for gaseous radioactivity and cesium-137 for particulate radioactivity (Half Lives greater than 8 days).

, The upper limit of 5 x 10' cpm is approximately 90 percent of full instrument scale, j SRAS Loaic Nodif1 cation l Action Statement 4 of Table 3.3-3, which applies only to th SRAS logic, pecifies that during surveillance testing the second inoperable channel must-l also be placed in the bypassed condition. For the SRAS logic, placing the second

inoperable channel in the tripped condition (as in Action Statement 2) could I result in the false generation of a- SRAS signal due to an -additional failure which causes a trip signal in either of the remaining channels at the onset of a LOCA. The false generation of tha SRAS signal leads to unacceptable

consequences for LOCA mitigattor.

i

!- With Action Statement 4, during the two-hour period when two channels are bypassed, no additional failure can result-in the laise generation of the SRAS

signal. However, an additional failure that prevents a trip of either of the two

!_ remaining channels may prevent the generation of a'true SRAS signal while in this :

! Action Statement. If no SRAS is generated at the appropriate time, operating i proceduresinstruct the operator to ensure that the SRAS actuation occurs when the refueling water storage tank level decreases. Due to the limited period of vulnerability, and the existence of operator requirements to manually initiate an SRAS if an automatic initiation does not occur, this risk is considered

acceptable.

! MILLSTONE - UNIT 2 B3/43-2 Amendment No. #7, 0146 i

,g*..

BASES (Continued)

Sensor Cabinet Power Sucoly Auctioneerina The auctioneering circuit of the ESFAS sensor cabinets ensures that two sensor cabinets do not de energize upon loss of a D.C. bus, thereby resulting in the false generation of an SRAS. Power source VA-10 provides normal power to sensor cabinet A and bar.kup power to sensor cabinet D. VA-40 provides normal power to sensor cabinet D and backup power to cabinet A. Power sources VA 20 and VA-30 and sensor cabinets B and C are simil.tly arranged.

It the normal or backup power source fo> an ESFAS Sensor Cabinet is lost, two sensor cabinets would be supplied from the same power source, but would still t be operating with no subsecuent trip signals present. However, any additional failure associated with th<s power source would result in the loss of the two sensor cabinets, consequently generating a false SRAS. The 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months Action Statement ensures that the probability of a Action Statement and an additional failure of the remaining power source, while in this Action Statement is sufficiently small.

3/4.3.3 MONITORING INSTRUMENTATION 3/4.3.3.1 RADIATION MONITORING INSTRUMENTATION The OPERABILITY of the radiation monitoring channels ensures that 1) the radiation levels are continually measured in the areas served by the individual channels and 2) the alarm or automatic action is initiated when the radiation level trip setpoint is exceeded.

The spent fuel storage area monitors provide a Aignal to direct the

, ventilation exhaust from the spent fuel storage area through a filter train when the dose rate exceeds the setpoint. The filter train is provided to reduce the particulate and iodine radioactivity released to the atmosphere.

Should an accident involving spent ful occur, the 100 -mR/hr actuation setpoint would be sufficient to limit any consequences at the exclusion area boundary to those evaluated in the NRC Safety Evaluation, Section 15 (May 1974).

MILLSTONE - UNIT 2 B 3/4 3-2a Amendment No. U7,__

0144

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ML20073S805

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