ML20043A977

Proposed Tech Specs Re Radiation Monitoring Instrumentation

ML20043A977
Person / Time
Site:	North Anna
Issue date:	05/16/1990
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20043A975	List: ML20043A974 ML20043A977
References
NUDOCS 9005230360
Download: ML20043A977 (9)

Text

. _ _

'a j 4

I

-l':

e

l li I

h

=

Proposed ~ Technical Specification Change:

l l

L North Anna - Unit -1 '

~

t i.

1;>

\\

)

i w

I 1

i,.

1 l-

.i Virginia Electric and Power. Company.

4

j I

i.

d

?-g

'l

- 90052303gg{@,f,hh3s

. ppR ADO PDC r

- F 1

1 t-m

,..e m.,,,

y

9 m

[

.-h e

z-

- x-

, j TABLE 3.3-6 (continued)

~

RADIATION MONITORINGINSTRUMENTATION s

E

'U CHANNELS APPUCABLE ALARM / TRIP MEASUREMENT INSTRUM' NT OPERABLE MODES SETPOINT

' RANGE ACTION '

'~

z.

2. PROCESS MONITORS (Cont'd)

S

c. Noble Gas High Range Effluent Monitors i.

Ventilation Vent # 1,2,3, & 4 Hi s4.72x106 Ci/sec

. 5 x 10-7. j o + 5 Ci/cc 35 7

Hi Hi 51.89x10 pCi/sec ii. Process Vent #

1 1,2,3,' & ' 4 Hi. 54.72x106 Ci/sec -

5 x 10-7-10 + 5pCi/cc. 35 7

R Hi Hi $1.69x10 pCi/sec-a Y

iii. Main-Steam ##

1/ loop -

1,2,3, & 4 Hi s1.0 mR/hr 10-2-10 + 7 ' ' mR/hr 35 Hi Hi 54.0 mR/hr

'y g.,. -

iv. Auxiliary Feedwater-Pump Turbine Exhaust.

1 1,2,3. & 4 Hi 50.7 mR/hr 10 - 2.1 o + 7 mR/hr 35 Hi Hi 52.8 mR/hr.

W a

is 3

Common to Unit 1 and Unit 2..

p

1. # : Main steam release path includes safaty valves, atmospheric steam dump valves and the decay heat release path.

s

+,-e-

..u.Ly,mm,_,_.

,h s

,.._,h%,

y

_m...

}

_+-e-.-.--

~--_.w--

,, - -., +

-_s---

.em s-

-4.'

3 l

. Attachment 2' i

d i

?

Proposed Technical' Specification Change.

q I

North : Anna Unit 2 '

h b

1

.i i

p:

Virginia Electric and Power Company h

i i

y,

.,l'

),

\\_'

g Y

- ~,

l.

-dhe..

MM.

=

a is, ai i

i.

m i h a

ii i i

. i iii.

d i i

iiim i i i i si

. n I.

I hsi h l -

l,,

2

~

d.

TABLE 3.3-6 (continued).'

- [

RADIATION MONITORING INSTRUMENTATION E

- U CHAtNELS APPUL ABi_E Al_ARMiTRf?

MEASUREMENT

N INSTRUMENT OPERABLE

_M.CQ)iS__

SETPOINi RANGE ACTION

2. PROCESS MONITORS (Contd)

c. Noble Gas High Ranoe Effluent Monitors i.

Ventilation Vent #

1 1,2,3. & 4 Hi $4.72x10 pCi/sec 5 x 10-7-10 + 5 Ci/cc 35 6

- Hi Hi 61.89x107 Ci/sec' li. Process Vent #

1 1,2,3, & 4

- Hi.s4.72x10 pCi/sec

-5 x 10-7-10 + 5 Ci/cc.,3 5 6

7 Hi Hi s1.89x10 nCi/sec

. k'

[

iii.' Main Steam -##

. 1/ loop 1,2,3, & 4 Hi s1.0 mR/ht:

10-2.1 o +7-r"vbr

- 35 Hi Hi 54.0 rnR/hr e*

iv. bcHary Feedwater Pump Turbine Exhaust 1

1,2,3, & 4 Hi s0.7 mR/hr 10-2-'10+7 ' mR/hr 35 Hi Hi 52.8 mR/hr

~

8 E"

Common to Unit 1 and Unit 2.

~ !?

t' # Main steam release path includes safety valves, atmospharic steam dump valves and the decay _ heat release path.

e e*m r

.yml.

-%ma.

.-e>n.e-%.

"isw we e

.Ah-w/meisew " phn,L.

'M-d chsi.

inr a

t-P p=

gu

-was #

w--

.t.%4.eu-m-v,wcem_

- - -a---%sa

.-.<s.w,w-.e-mn-w..-m,m..z k,--.e,-a,.%.2

_.nm,nssamm.m.

s r

Li

, mism

t e.

. v Discussion' of_ Proposedi Change

. North Anna Units -1 and t Virginia-Electric and - Power Company i

m, 1

-1

~. _

q

.y 4

Discussion of Proposed Technica! Specification Change The proposed changes to the North Anna Units 1 and 2 Technical Soecifications are to update the high range effluent monitor alarm set points in Table 3.3 6 'of Specification 3.3.3.1. The high range efflue'nt monitors and associated Technical

]

Specifications were added due to the accident monitoring concerns relayed in NUREG j

0737. The "Hi" and "Hi Hi" alarms were intended to alert the control room operators of 1

impending need to declare a site area or general emergency. The criteria for declaring a site area or general. emergency are in-our Emergency Plan. Implementing-

..4 Procedures (EPIPs), which have been revised since the. original setpoint calculations were done. These procedures contain conservative' assumptions to be used for 4

setpoint calculations SJch as worst case dispers:on factors.

3 The proposed Ventilation Vent and' Process Vent setpoints represent-substantial reductions (factors on the order of 1000) from currently approved values, which were apparently based on the maximum range of the in.struments.' Because the-ACTION statement allows _a more conservative setpoint, the station has been operating with lower setpoints based on the EPIPs.. Also, the Ventilation Ven.t and Process Vent monitors have been modified to multiply the concentration by the_ flow rate and report releases in pCl/sec, a more relevant measure than the currently approved Ci/cc. The -

"Hi" setpoint for item 2.c.i, the ventilation vent monitor, in Table.3.3-6 of Specification 3.3.3.1'is "5x10 "(pCi/cc) and should be changed to."s4.72x10 ' Ci/sec".- The'"Hi Hi" 2

6 setpoint should be changed from "10 "(pCi/cc) to "s1.89x107 Ci/sec". In item 2.c.ii, 3

t the process vent moriitor, the "Hi" setpoint should be changed from "5x10 "( Ci/cc) to.

4 "s4.72x106 pCl/sec" and the "Hi Hi". setpoin' changed from "10 "( Cl/cc) to "s1.89x10,

5 7

l pCi/sec." The changes will also clarify the Specification by explicitly including the "s" l

symbol and the units of measure.

(

L The auxiliary feedwater pump turbine exhaust monitor and the main. steam moraor setpoints are being changed due to changes.in the EPIPs. These monitors would be-needed if the secondary system was severely contaminated and the turbine powered auxiliary feedwater pump or the main steam safety relief valves were used. The Hi setpoints are based on the site area emergency criteria in EPIP 4.07 and the Hi Hi l

aetpoints are based on the general emergency criteria. The setpoints are calculated using the Xe 133 dosa conversion factor from Regult Try Guide 1.109 and dispersion factors from EPIP 4.10. Flow rates for main steam a.id auxiliary feedwater pump turbine exhaust remain unchanged from the original caulation.

The criteria in EPlP 4.07 for me site area and general emergencies are 500 mR and D

2000 mR respectively during the 2.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> it would take to evacuate the area within two miles around the station. This compares to the original criteria of 50 mR/hr and' i

1000 mR/hr. This explains why, although the Hi-Hi setpoints are reduced, the Hi l

setpoints for the auxiliary feedwater pump turbine exhaust and the main steam s

monitors are increased. In either case, the new values are preferred because they are more closely related to the accepted criteria for declaring an emergency. We therefore wish to change the "Hi" setpoint in item 2.c.iii, the main steam monitor, from ".26 mr/hr" l

u

.~

~

L

• i

.)

. l to "$1.0 mR/hr" and the "Hi Hi" setpoint from "S.14 mr/hr" to "s4.0 mR/hr." In item 2.c.iv, the auxiliary feedwater pump turbine exhaust monitor,'the "Hi" setpoint should be.'

changed from "0.2 mr/hr" to "s0.7 mR/hr" and the "Hi Hi" setpoint from "-4.03 mr/hr". to "s2.8 mR/hr" l

i

'. f

'i

.i l

1 I

1

. l 1

S. :

. )

.1

')

i v.

I i

. ~.

\\.

10 t

1

.,c ;

~

i 1

Attachment '4 J

l h

't

=;

t t

10 CFR 50.92 Evaluation

. North Anna Units 1 and 2 4

.t' ll l

it i

Virginie Electric an'd Power Company

~,

i

-1 1

f 1

- Basis for No Significant Hazards -Determination

-l The proposed change does not involve a significant hazards consideration as defined l

In 10 CFR 50.92 because' operation of North Anna Units 1 and 2 in accordance with this change would not' (1) involve a significant ' increase in the probability or cons _equence of an accident'or malfunc'm of equipment important to safety _ as previously evaluated in the Finai Safety Analysis Report. The change only affects the setpoints of the high range effluent monitors and will therefore not alter the probability of any accident. The use of _ setpoints based on current' Emergency Plan. Implementing Procedures mayfimprove operator awareness and therefore will not increase the consequences of an 4

accident

-(2) create the possibility of a new or different kind of accident'or a malfunction '

~

of a different type than any previously evaluated in)the Final Safety Analysis Report The only safety function these systems provide is to j

provide information on releases They therefore cannot create a new ors

.i different accident.

l1 (3). involve a reduction in a margin of safety The revision will_-provide the operator with more meaningful indication and will therefore not involve a reduction in a safety margin; Thereforo, pursuant to 10.CFR 50.92, based on th'e above considerations, it has been determined tht this change dces not involve a significant hazards consideration.

l i

4

- l 1

i 1

W

'