ML20066F462

Proposed Tech Specs Re Suppression Pool Temp Monitoring

ML20066F462
Person / Time
Site:	Hatch
Issue date:	01/15/1991
From:	GEORGIA POWER CO.
To:
Shared Package
ML20066F460	List: HL-1359, Responds to Telcon Requests for Addl Info Re 900126 Application for Amends to Licenses DPR-57 & NPF-5,changing Tech Specs Re Suppression Pool Temp Monitoring ML20066F462
References
NUDOCS 9101240002
Download: ML20066F462 (7)

Text

. . . - . .. .. . - . - . . - . . . - . . . - . . - . - -.

z; t

.l 1

-ENCLOSURE 21

-! ~

PLANT HATCH:- UNITS 1,32'- >

NRC DOCKETS 50-321, 50 366- -

L . OPERATING LICENSES.'DPR-57,-: NPF-5' Jf l REQUEST FOR ADDITIONAL.INFORMATION: }

l SUPPRESSION POOL TEMPERATURE' MONITORING  ?

q

'PAGE CHANGE' INSTRUCTIONS 'I f

-UNIT:1 'i

=,

L Remove Paae: Insert' Pace'  :)

-3.7-29 3.7-29 <

3.7-29a c3.7-29b- ,

UNIT 2 1

-a Remove-Pag.g ,lpsert Paao-B 3/4 6 4 6 3/4_6 '

-B 3/4:6-4a-B3/46-4b_ i i

'l I

l j HL-1359

.001276- E2-1 i 9101240002 910115 PDR ADOCK 05000321 p PDR ,

1 l l

BASES FOR LlHITING CONDITIONS FOR OPERATION 3.7.A.1. Pressure Suppression Chamber (Continued)

Experimental data indicate that excessive steam condensing loads can be avoided if the peak temperature of the pressure suppression pool is maintained below 160'F ouring any period of relief valve operation with 4 sonic conditions at the discharge exit. Specifications have been placed on the envelope of reactor operating conditions sc that the rn ctor can be depressurized in a timely manner to avoid the regime of potentially high pressure suppression chamber loadings, in addition to the limits on temperature of the suppression chamber pool water, operating procedures cefine that action to be taken in the event a relief valve inadvertently opens or Sticks open. As a minimum this action shall include: (1) use of all available means to close the valve, (2) initiate suppression pool water cooling heat exchangers, (3) initiate reactor shutdown, and (4) if other relief valves are use' co depressurize the reactor, their discharge shall be separated f ro'. that of the stuck-open relief valve to assure mixing and uniformity of energy insertion to the pool.

Because of the large volume and thermal capacity of the suppression pool, the volume and temperature norm ily changes very slowly and monitoring these parameters daily is suf ficknt to establish any temperature trends.

By requiring the suppression pool temperature to be continually monitored and frequently logged during periods of significant heat addition, the temperature trends will be closely followed so that appropriate action cen be taken. The requirement for 6n external visual examination following 6ny event where potentially high loadings could occur provides assurance that no significant damage was encountered. Particular attention should be focused on structural discontinuities in the vicinity of the relief valve discharge since these are expected to be the points of highest stress.

The average (or bulk) suppression pool temperature limits specified in paragraphs 3.7.A.1 and 4.7. A.1 are normally monitored using a weighted average of 15 temperature sensors. Four sensors, T48-N009A through H0090, are located in the lower half of-the suppression pool and 11 sensors. T48-N301 through N311, are located in the upper half of the suppression pool. The 4 lower sensors are averaged and the 11 upper sensors are averaged. The bulk suppression pool temperature is the average of the upper and lower average temperature. Should more than two of the 300 series sensors be determined inoperable when the suppression chamber is required, a preplanned alternate method of determining average temperature may be used. The table below illustrates the correctici factor. (if any) tc be added to the operable N009 series elements in this condition. These correction factors for plant conditions (a), (b), and (c) were developed f rom a detailed review of Plant Hatch suppression pool temperature data.

HATCH - UNIT 1 3.7-29 Proposed TS/03403320-16 1

(. _ _ _ _ _ _ _ - . _ _ _ _

BASES FOR LIMITING COND1110hS TDR OPERA 110N

-CorrectionFactor-('F)

Plant Condition (See Notes) to Operable N0Q9A-D Elements-(a) Normal Operation;' Torus coolit.g3not 5-Operating (Note 1);_No HPCI Testing j (Note 2);_No Leaking SRV(s)--;(Note 3)r l

(b) Normal Operation; With or.~without (Note 4)- l Torus Cooling Operating; HPCI Testing; 1 With or without Le6 king SRV(s) i (c) Normal Operation; Torus Cooling 0~

I Operating; No HPCI Testing; With or without. Leaking'SRY(s)

(d) Abnormal Operation;'With or.Without N009 Elements:-if1- i Torus Cooling Operating;:. SPDS Inoperable; 1 Significant Heat Addition to' j SuppressionLPool ,.

/

Notes:  !

i' (1) Torus cooling is at least one_1 rop of RHR.in pool cooling'or_ torus.

spray _ mode.

(2) The Technical Specificatin '1mit-f or this condition is ,105'F. .

9 (3) .A leaking SRV is defined'as an SRV experiencing significant: steam d

leakage past the seat.- All the steam is not cor.densed in-the SRV

~

discharge line and, therefore..'results in steam expulsion into pool, --

(4) Without upper pool temperature-indication, HPCI testing-time should be limited.to assure the bulk pool temperature does not exceed 105'F.

-Pool temperature data _should still be recorded each-5 minutes as'

. instructed by Technical Spa.ifications, but.the:run. time should be administratively controlled by:the following:-

~

i~ Max Run Time in Minutes = (105 - Tinitial) x 2, where Tinitial is the pool! temperature taken prior lto the _ test with: ,

torus cooling operating. This equation ~ assumes a--30*F/ hour rise in l bulk = pool temperature, i

j

HATCH - UNIT'l' 3.7-29a. Proposed TS/0340q/320-16 a

f r

-~

~

BASES F0, LIMITING CONDITIONS FOR OPERATION i

[

J

^

(This page intentionally.left bla'k)

(

c HATCH - UiT 1 3.7-29b Proposed TS/03404/320- 4

1 q

i

. j

. CONTAINMENT-SYSTEMS  ;

l )

BASES _

_ i R

DEPRESSURI2ATION SYS1 EMS (Continued).

d Exherimentaldataindicatesthatexcessivesteamcondensingloadscan be avoided if the-peak temperature of the suppression pool is maintained j{

below 160'F during any period of relief valve operation with sonic  !

conditions at the discharge exit. Specifications ha've been placedlon  ;

the envelope of reactor-operating conditions so thatithe reactor can be depressurized in a timely manner to avoid the regime ^of potentially high suppression chamber loadings.

Because of the large volume and thermal capac'lty of_the suppression pool,-the volume and temperature normally-changes-very slowly and-monitoring j these parameters dally is sufficient to establish any temperature trends.

By requiring the suppression pool temperature to be frequently logged during periods of significant heat addition, the temperature trends will '

be closely followed so that appropriate action can be-taken. The~ require-ment for an external visual examination following any event where potentially high loadings could occur provides assurance that no significant damage-was encountered. Particular attention should be focused on structural discontinuities in the vicinity of the relief. valve-discharge-since these are expected to be.the points of highest stress.

l In addition to the limits on temperature _of the suppresstor chamber pool water, operating procedures define the action'to be taken:in the event a safety / relief valve inadvertently opens or sticks open. .As_a minimum,-this action shall include: (1) use of all available means to close the valve, (2) initiate suppression pool water cooling -(3) initiate' i reactor shutdown, and (4) if other safety / relief-valves are used to depres-surize the reactor, their distharge shall be-separated-from that'of the

! stuck-open safety / relief valve to assure mixing and uniformity of energy ,

insertion to the pool. '

l The average (or bulk) suppression pool temperature limits specified in I

paragraphs 3.6.2.1 and 4.6.2.1 are normally monitored using a weighted averige I of 15 temperature sensors. Four sensors,'2T48-N009A through N0090, are located in the lower half of the suppression pool and 11 sensors, ET48-N301 through N311, are located.In the upper half-of the suppression pool. The 4 lower l sensors are_ averaged and the li upper sensors-are averaged. The bulk j suppression pool temperature is the-average of the upper and lower average l temperature. -Should more than two of the 300 series sensors be determined l inoperable while in Conditions 1, 2, or 3, a prer,10nned alternate method of determining average temperature may be used Ine table below illustrates the correctic7 factor (if any) to be added to the operable N009 series elements in this condition. These1 correction factors for plant conditions i (a), (b), and (c) were deve) ped from a detailed review of Plant Hatch. '

suppression pool temperature data. ,

HATCH - UNIT 2 B 3/4 6-4 Proposed TS/0338q/320-0 J

1 m. y CONTAINMENT SYSTEMS' BASES-Correctton FactorJ(*F)

Plant condition (See Notes) to Operable N009A-D' Elements.

(a) _ Normal Operation; Torus Cooling;not 5

-Operating (Note 1);~-No HPCI' Testing-(Note 2); No Leaking SRV(s)-(Note 3)

(b) Normal Operation;-With.or without' -(Note 4)4 Torus Cooling Operating;7HPCI' Testing; With or without Leaking SRV(s) R (c)  : Normal Operation; Torus-Cooling- 0 Operating; No HPCI Testing;.

Hith or without Leaking SRV(s)=

(d) Abnormal _ Operation;-With or without -N009 Elements if-Torus Cooling Operating;- SPDS-Inoperable.

Significant Heat Addition to Suppression Pool Notes:

1. Torus cooling is at least one loop of RHR;in' pool cooling'orctorus' spray mode. '

2. -The Technical Specification limit'fo'rethisEcondition is 105*F.

3. A leaking SRV'is defined as an SRV-experiencing significant steam leakage past the seat _ All:the-steam.is:not condensedJin?-the-SRV.

discharge line and,=therefore,:results in_stea.m_ expulsion 71nto

. pool.

~

-4. Without. upper pool temperature indication, HPCIrtesting time should be.

~

limited'to assure the_ bulk pool temperature does_notiexceed 105'F; Pool temperature data should still;be recorded each Siminutes asi instructed by Technical Specifications, but_the run: time should be.

administratively controlled by the-following:-

Max Run Time in Minutes V (105'-:Tioiii.i) x-2,-

where Tinisi., is the pool temperature taken prior to-the test with-torus cooling operating. This equation assumes _a 30*F/ hour rise in-1 tulk pool temperature.

HATCH --UNIT 2 B 3/4 6-4a Proposed TS/0338q/320-0.

. _ _ _ _ _ =m

• % g  :-;

i i

)

CONTAINMENT SYSTEMS BASES 3/4.6.3 PRIMARY CONTAINMENT ISOLATION VALVES The OPERABILITY of the primary containment isolation valves ensures that the primary containment atmosphere will be isolated-from the outside a environment in the event of a release of radioactive material to the d primary containment atmosphere or pressurization of the containment.

Primary containment isolation within the time limits specified ensures i that the release of radioactive material to the environment will-be consist-ent with the assumptions used in the analyses for a LOCA._ Only one closed valve in each penetration line is required to maintain the integrity of the containment.

i i

l

)

s l

1 HATCH - UNIT 2- B 3/4 6-4b Proposed IS/0338q/320-0

. .