ML19327C204

Suppls 890615 Response to NRC Bulletin 88-004, Potential Safety-Related Pump Loss. Lower than Expected Recirculation Flow Due to Improperly Designed Flow Restricting Orifice. Reportability Per Part 21 Will Be Determined by 891117

ML19327C204
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/13/1989
From:	James Fisicaro ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
0CAN118911, CAN118911, IEB-88-004, IEB-88-4, NUDOCS 8911210159
Download: ML19327C204 (3)

Text

'

r . . .

s 1

R

'

fLa, ' '

~" p. j /

i

'~

) Arkansas Power & Ught Company

\,. _ ._ _ /

' Arkansas Nuclear Ono ,

/ 4e 4 * "" t '

noute 3. Box 137 G I

Russe!!wlle. AR 72831.

Tel 501964 3100 r.

,m

-t'

( 'k g

( t V

E p

No'vember 13. 1989

, ,4 <

SCAN 118911 m ,

d ' U. S. Nuclear Regulatory Commission ,

Document Control Desk ,

Mail-Station P1-137' i , Washington, DC':20555-

Subject:

Arkansas Nuclear One - Units 1 & 2

)l!f 5 ' Docket Nos. 50-313 and 50-368 License Nos. DFR-51 and NPF-6 Bulletin 88-04 Potential H Safety-Related Pump Loss

- June 15, 1989 Response 1

Gentlemen:

In our l'etter dated June 15, 1989 (9CAN068911), AP&L provided a response to i

q. Bulletin 88 Potential Safety Related Pump Loss. The purpose of this B . letter:is to provide you with an additional explanation of a statement contained in that letter concerning the adequacy of recirculation flow for the ANO-2 Emergency Feedwater Pumps, 2P-7A & 8. In response to Question 3 we stated "A review was performed of EFW pump flows versus the new minimum 4- flow requirements provided by the pump manufacturer. The results show that adequate; pump flows to prevent pump damage are achieved during anticipated

-modes of pump operation." We have subsequently determined that this response was based upon incomplete information. Specifically, the individual preparing the response believed the recirculation flow rate for these pumps was slightly greater than 45 gpm (the vendor concurred minimum 4 flow rate) but in fact the recirculation flow rate was approximately 20 to '

L :25 gpm. Subsequent conversations with the vendor, after discovery of this ,

oversight, indicated that a 20 gpm flow rate is acceptable. We offer the r following information to clarify and explain the discrepancy. I

'4 In order to respond to Bulletin 88-04, AP&L supplied the pump vendor with

- l' . system operating data including the minimum recirculation flow measured g during previous surveillances. The ficw measured during these surveillances was documented as approximately 47 gpm. Based on this system specific input

", f '

and vendor supplied design data, the vendor confirmed in December 1988 that a 45 gpm recirculation flow rate was acceptable.

However, in January 1989 an apparent discrepancy was discovered with the ',

ANO-2 EFW recirculation line flow instrument. Following calibration, the g, previous indicated flow reading of approy.imately 47 gpm was reduced to 8911210139 891113 PDR ADOCK 05000313 N

li , Cl PDC An Entera, Commw fg

& , h

[

D ..

U. S. Nhc Page 2 ,

November 13, 1989 approximately 20 to 25 cpm. A Condition Report (a mechanism used by AP&L to ,

disposition identified discrepancies) was initiated based upon this apparent reduced flowrate. It was initially thought that the flow instrument was in error.. The individual responsible for preparing AP&L's response to Bulletin 88-04 concurred in this position based upon his knowledge of the previous flow history and the specification for the flow restricting orifice which was to provide for a recirculation flow of approximately 50 gpm. Although .

subsequent evaluations showed that this reduced flow of 20-25 gpm was most probably correct, the individual who prepared the Bulletin response was u-aware of this information.

As previously mentioned we have reviewed the pump data at the lower flow rate with the pump vendor. Based upon this information, the vendor confirmed pump operability when operating at this lower flowrate. AP&L has evaluated

• L and concurs with this position. Nonetheless AP&L has modified the existing l

orifices to increase the recirculation flow rate to enhance margin. Following review of the post modification test data AP&L will assess whether future modifications are desirable.

We are presently reevaluating the method by which the minimum flow requirements for all the applicable pumps were determined in preparation for our response to Bulletin 88-04. This evaluation will be completed by December 15, 1989.

Additionally, we are looking into our processes for preparing and submitting correspondence to the NRC and will make any necessary changes to improve the overall process. This review will be completed by December 15, 1989. ,

i The lower than expected recirculation flow was due to an improperly designed flow restricting orifice. We are currently evaluating the reportability of this deficiency under the provisions of 10CFR21. This evaluation will be completed by November 17, 1989. We are also reviewing other orifice designs supplied to use by the same vendor to assure there are no other deficiencies.

If you have any questions on this letter, please contact me.

l Very truly yours,

.bE" l James . Fisicaro i Manager, Licensing l

JJF/1w cc: U. S. Nuclear Regulatory Commission l' Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, TX. 76011

(

l

~ ^

(7 .

(

i

.e. . ,

L '.'

e * '

t- U, S. NRC  !

Page 3  !

November 13, 1989 h  !

[ NRC Senior Resident Inspector l Arkansas Nuclear One - ANO-1 & 2 i Number 1. Nuclear Plant Road Russellville, AR 72801 Mr. Craig Harbuck NRR Project Manager, Region IV/ANO-1 U. S. Nuclear Regulatory Commission NRR Mail Stop-13-D-18 1 White Flint North 11555 Rockville Pike ,

Rockville, MO '20852  ;

Mr. Chet Poslusny NRR Project Manager, Region IV/ANO-2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-D-18 1 White Flint North 11555 Rockville Pike Rockville, MD 20852 ANO-DCC File -

l' l

s.