ML20039D550

Forwards Proposed Change to FSAR Concerning Resolution of Open Tech Spec Item Re End of Cycle Recirculation Pump Trip. Proposed Change Will Be Documented in Amend to FSAR

ML20039D550
Person / Time
Site:	LaSalle
Issue date:	12/29/1981
From:	Sargent C COMMONWEALTH EDISON CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 8201050191
Download: ML20039D550 (5)

Text

__

'/

N Commonwealth Edison

/

) one First National Plaza. Chictgo, Illinois

( T 7 Address Reply to: Post Office Box 767

,/ Chicago. Illinois 60690 N

i December 29, 1981

//

'b Mr. A. Schwence r, Chief RECEIVED Licensing Branch #2 2

Division of Licensing JAN4 1982>

U.

S. Nuclear Regulatory Commission

& N amit gygg g,,,,,

=

Washington, DC 20555 kam

,d

Subject:

LaSalle County Station Units 1 and 2 Proposed FSAR Change Concerning End-of-Cycle Recirculation Pump Trip NRC Docket Nos.-50-373/374

Dear Mr. Schwencer:

The purpose of this transmittal is to provide a proposed revision to the LaSalle County Station FSAR.

This proposed change provides the necessary support for resolution of an open Technical Specification item.

The open Technical Specification item concerns the response time o f end-of-cycle recirculation pump trip (EOC-RPT) actuation instrumentation.

Currently the response time change from 0.140 seconds to 0.190 seconds is shown as an open item in the LaSalle Technical Specification pending submission of an FSAR change incorporating the 0.190 second value.

It is our understanding that this information should provide a basis for clearing the Technical Specification issue on EOC-RPT.

The attached proposed changes will be documented in an Amendment to the FSAR.

If there are any questions in this regard, please contact this office.

Ve ry truly yours, bb C. E. Sa rgent Nuclea r Licensing Administrator Attachment b['

cc:

NRC P,esident Inspector - LSCS 3110N 0201050191 811229 I

PDR ADOCK 05000373 U d A

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h Tut bine gcner ator PLU ttip 3

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initiates main tur bine bypass g

system operation.

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0 Fast turbine control valve

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closur e initiates reactor scram.

O Past turbine control valve closure initiates a recirc pump trip (RPT).

0.07 Turbine Control valves closed.

0.1 Turbine bypass valves start to open.

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a ator c::cutc L t t:.,er s

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ecca C IIecreasing in-cure flow a r ic::c al circulation.

'.ef "ilvas activate sequentially 1,35, 1.52, 1.67, 1.J3,

. :i 2.07 in _ t o.. y.> :

1, 2,

3, 4,

and 5.

4.08 High water level tr ip L8 initiates feedwater trip.

(Est) 5.2, 5.6, 6.0, Relief Valves close sequentially 6.0, 6.2, and 7.1 in groups:

5, 4,

3, 2, and 1.

I 24.8 (est)*

Turbine bypass valves star t to close.

32.5 (cst)*

~

-s S;p ce ulver c'c

~1 31.56*

Turbine bypess valves reopen on pressure signal.

38.31*

L2 vessel water level trip initiates ::SIV's.

L2 vessel water level trip initiates RCIC and HPCS (not simulated).

• Event and times are typical of FEDY solution for this c. vent.

They are included here to record the time-line of events l'eyond the 15 second results fron ODYU mcdel.

15.2-4 m

7, y, Z

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\\1 1

L e

tr.

The. c y m. _ of mts i,r lo;s of,..

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.t lead accur.p<.nied by failt,ce of the tur!>ine bypans valves (Figure 15.2.2-2) is as follows:

l TIME

'8 (sec)

EVENT

-0.015 (approx)

T'ir b i a c -g e ne r a tor detection j

of loss of generator load.

I i

0

-'u r b i c.c -g e n e r a t or power load unbalance (PLU) devices trip to i citiate turbine control valve fast closure.

O Turbine b pas valves fail i

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Tj

+

v.U,

..ir m ne coa t t u t c a,t v e s c u. wa.

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Eecirc pai.e ac; tor circuit breakers open thus decreasing in-coce flos to natural circulation.

1.09, 1.20, 1.31, Relief valves actuate sequentially 1.45, and 1.60 in groups:

1, 2,

3, 4, and S.

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=

~

c 1 w..

cinco cc lm-t) 7 f.e,

.2

, ~,

1 11.38, 12.56*

Re li e f calvcs actuate sequentially in grcups:

1 and 2.

(Est) 17.6, 18.8*

Relief valves close sep.entially in groups:

2 and 1.

24.3*

Group 1 Relief Valves actuated.

3 2.0 (es t)

• Grocp 1 ~ ~; '_ i i f "a l v e s c lo s e d.

" vents and t ig.e s are tjpical of EDI solution fo-i. Y s c c. nt.

They are included here to r3 cord th.; u:..e-line of events.-;ycnd the 15 second results fran GDYN 1.cdel.

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. f~r,

t.

c_

...p i.

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'.Y 1(81 Tulbine trip initiates bypass operation.

0.01

'4ain turbine stop valves reach 90E open pesition and initiato reactor scram trip.

4ain turbine stop valves reach 90c open position and initiate tecirculation pump trip (RPT).

a 0.10 Turbine stop valves closed.

Turbinc lypass valvec start to

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r t

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Z ~.

L.

s.

a.

nd 5.

4.53 rec s.tct trip on high water level i L8).

(Est) 5.2, 5.5, Relief valves close sequenti-5.9, 6.2 and 7.0 ally by groups:

5, c, 3,

2, and 1.

nitia'.cs to clore

'- c

- i,

.a l.

32.2 (est)

Tu-bina bypass closed.

38.67 Low level trip (L2) initiates a main steam line isolation.

Low level trip (L2) initiates RCIC and HPCS (not simulated).

39.23 Turbine bypass reopen on pressure increase at turbine inlet.

9

=

7 3 -

6

r; 3

i o

Ev gs ODYN - Turbine Trip ',;ithoat ncy Classification 15.2.3A Tdentification of Causes and Freaue iniLiate lfunctions will 15.2.3A.1 turbine or nuclear system ma separator and moisture operator A variety of Some examples are:

vibrations, low condenser vacuum, a turbine trip.

large heater drain tank high levels, fluid pressure, loss of control and reactor high water level.

lockout, infrequent an is categorized as to be as follows:

A turbine trip without bypassThe frequency is expected The basis for this 6 years.

of the bypass 0.0064/ plant year with 11TBE of 15that the f ailure rate d rejection.

incident.

the same as for generator loatrip frequency of frequency prediction is 1.22 events ear.

'alcce is 0.0048,'*5 'he turine

- of 0.0064 per plant y n n1 c ser

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.c

,= -

c-

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b h:

c...

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.1 s..s._ ice o; failure of c..;

Tae accanpanying follo./s:

is as 15.2.3-2)

Event Time Turbine trip initiates closure (sec) i of main stop valves.

0 to Turbine bypass valves fail c1 r-te.

Main turbine stop valvc;90 0.011 reactor scram trip.

Main turbine stop valv trip (RPT a recirculation pump Turbine stop valves closed.

f Recirculation pump noter ciretj 0.1 breakers open causing decre 0E[ O. /9 in core flow

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tion.

19.'-17 k

...