ML20196H432
| ML20196H432 | |
| Person / Time | |
|---|---|
| Issue date: | 07/21/1997 |
| From: | Birmingham J NRC (Affiliation Not Assigned) |
| To: | Foster W BABCOCK & WILCOX OPERATING PLANTS OWNERS GROUP |
| References | |
| PROJECT-693 TAC-M99019, NUDOCS 9707250188 | |
| Download: ML20196H432 (4) | |
Text
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e ,
July 21, 1997 E
- Mr. W.-W. Foster, Chairman . ,
D&WOG Steering Committee l P.O.. Box 10935 Lynchburg, VA 24506-0935
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION RELATIVE TO THE HIGH PRESSURE INJECTION PUMP CAVITATION AT OCONEE UNIT-3 (M99019) , j
Dear Mr. Foster:
During the shutdown of Oconee Unit-3 on May 2, 1997, two.of the three Makeup /High-Pressure Injection Pumps (MU/HPI) were damaged as;a result of I inadequate water inventory in the Letdown Storage Tank. Following this event, j
-the NRC' asked the Babcock and Wilcox Owners Group (B&WOG) to review the !
potential for common mode failure-of the HPI system and to address any i problems. The B&W0G provided FTI Report 50-5000230-00 in response to that request. The NRC staff reviewed the report and has determined the need for addition ~al information. Accordingly, NRC-requests that the B&WOG provide a response to the enclosed questions by August 8, ~1997. Your response should be addressed to tbs NRC Document Control Desk and should reference the B&WOG Project No. 693. 1 If you have any questions on this matter, please call me at 301/415-2829 or email jlb49nrc. gov.
Sincerely, Original Sianed By:
Joseph L. Bi'rmingham, Project Manager Generic Issues and Environmental ,
Projects Branch- . l Office of Nuclear Reactor Regulation
Enclosure:
As stated go cc w/ encl: See next page i Project No. 693 FbbT t 5!
DISTR'IBUTION:
Docket File PUBLIC BSheron JBirmingham JLyons
~PGE8 R/F MLSlosson FAkstulewicz DLaBarge JFlack .
DMatthews CJackson MChatterton OGC ACRS D0'Neal .
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. Document Name: G:\JLB\HPI.BRK2.LTR i i
- See previous concurrence r\ ,; /
OFFICE PGEB:DRPM* SC/PGEB:DRPM* C/ [ d SA C/SRXB:DSSA* C/Rdd fDRPM NAME JBirmingham:sw FAkstulewicz JF1@ JLyons DMaNews DATE 07/14/97 07/I4 /97 07/fTfh7 07/16/97 07/J.}/97 V
9707250188 970721 PDR TOPRP EMVBW C PDR NiiC FJE CiFRdlCDPbyr r4 mr . . . - . - . .- _. -- .
l Q Ct0y p t UNITED STATES l t < E NUCLEAR REGULATORY COMMISSION I f WASHINGTON, D.C. 30666 0001
%4*****/ July 21, 1997 Mr. W. W. Foster, Chairman B&WOG Steering Committee P.O. Box 10935 Lynchburg, VA 24506-0935
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION RELATIVE TO THE HIGH-PRESSURE INJECTION PUMP CAVITATION AT OCONEE UNIT-3 (M99019) 4
Dear Mr. Foster:
During the shutdown of Oconee Unit-3 on May 2,1997, two of the three l Makeup /High-Pressure Injection Pumps (MU/HPI) were damaged as a result of l inadequate water inventory in the Letdown Storage Tank. Following this event, l
the NRC asked the Babcock and Wilcox Owners Group (B&WOG) to review the potential for common mode failure of the HPI system and to address any i problems. The B&WOG provided FTI Report 50-5000230-00 in response to that 1 request. The NRC staff reviewed the report and has determined the need for
'. additional information. Accordingly, NRC requests that the B&WOG provide a response to the enclosed questions by August 8, 1997. Your response should be addressed to the NRC Document Control Desk and should reference the B&WOG l Project No. 693. l If you have any questions on this matter, please call me at 301/415-2829 or email jlb40nrc. gov.
Sincerely, -
Q R d'rW9 Joseph L. Birmingham, Project Manager Generic Issues and Environmental Projects Branch ;
Office of Nuclear Reactor Regulation !
Enclosure:
As stated cc w/ enc 1: See next page Project No. 693 l
l l
1 i
i
! BWOG Report on the Generic
! Implications of Oconee Unit-3 Makeup Pump Event Request for Additional Information
- 1. - For ANO-1, CR-3, and TMI-1 the normal configuration, with thne available or
- operable HPI pumps, is described in the report. The plant technical specifications reqdire only two trains of HPI or two operable HPI pumps. Is operation with the two Es selected pumps on the same suction header as the MUT prohibited (for both two and three HPI pumps operable)? Please reference the requirement that prohibits this configuration. If there is no prohibition for operation in this configuration for
, any of the plants please indicate why it is acceptable to allow this configuration.
- 2. The report indicates that analyses have been performed for CR-3, Oconee and 1MI-1 to prevent gas from being swept into the HPI suction and that at AN0-1 operator action
- is credited to isolate the MUT. Although the staff does not intend to review the i analyses, please describe what analyses have been performed for ANO-1 to allow
- credit for operator action. For example, how long do operators have to isolate the i
MUT before gas can be swept into the system? Is there an acceptable window of operation for MUT pressure and level? How is operation in this window monitored (i.e., alarms in the control room when the operating point is outside the acceptable
- window)?
- 3. For ANO-1, CR-3 and THI-1 please indicate if both level transmitters for the MUT l 1evel instrumentation have control room alarms.
1 l 4. For ANO-1, CR-3 and THI-1 please provide additional justification for the adequacy j of only one pressure transmitter for the MUT. Please include the possibility of the 2
pressure transmitter drifting high, low or failing as is, in addition to just
- failing high or low. These types of failures could go undetected for long periods of time. Because MUT pressure and level are administrative 1y controlled to assure HPI operability, the HPI could be inoperable and undetected for long periods of j time.
! 5. The report indicates that for some accidents CR-3 and ANO-1 continue to recirculate i HPI flow to the MUT after the swapover of the HPI suction from the borated water i storage tank to the discharge of the low pressure safety injection pumps. For these
!- plants, please provide greater detail how filling and pressurizing the MUT is ,
j prevented. Is the potential for the diversion of flow from the sump or the radiological consequences of lifting the MUT relief valve considered in other
- aspects of the plant design (operator dose calculations, NPSil issues while in ECCS recirculation mode)?
1 6. It was noted in the report that the TMI-1 PRA study recommended further evaluation of operation with a common su nion header (cross-connects open). The evaluation concluded the common suction header configuration resulted in a slightly lower core damage frequency (CDF). Please indicate the magnitude of the expected decrease and provide a discussion on the reasons for a lower CDF for this configuration.
Enclosure
f cc: B&W Owners Group Project No. 693 l
Mr. Robert W. Keaten, Chairman Mr. J. J. Kelly, Manager B&WOG Executive Committee B&W Owners Group Services l Vice President & Director of Framatome Technologies, Inc. !
Technical Functions P.O. Box 10935 i GPU Nuclear Corporation Lynchburg, VA 24506-0935 One Upper Pond Road '
Parsippany, NJ 07054 Mr. R. B. Borsum, Manager Mr. J. H. Taylor, Manager l Rockville Licensing Operations Licensing Services Framatome Technologies, Inc. Framatome Technologies, Inc. ,
1700 Rockvilia Pike, Suite 525 P.O. Box 10935 l Rockville, MD 20852-1631 Lynchburg, VA 24506-0935 l
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