ML20212A334
| ML20212A334 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 12/30/1986 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 2NRC-6-131, NUDOCS 8703030333 | |
| Download: ML20212A334 (4) | |
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2NRC-6-131 Beaver Valley No. 2 Unit Project Organization S.E.G. Building Telecopy (
Ext.160 P.o. Box 328 DeC. 30, 1986 Shippingport, PA 15077 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Mr. Stewart D. Ebneter, Director Division of Reactor Safety
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Inspection Report 50-412/86-32
REFERENCE:
Letter dated November 28, 1986 (S. D. Ebneter to J. J. Carey)
Gentlemen:
The above referenced letter transmitted a Notice of Deviation as Appendix A.
The attachment to this letter provides Duquesne Light Company's (DLC) response pursuant to the requirements of the NRC's Notice of Deviation.
DUQUESNE LIGHT COMPANY
~ J.L4. Carey v
Sr. Vice President LMR/ijr NR/IR/8632 Attachment cc:
Mr. P. Tam, Project Manager (w/a)
Ms. A. A. Asars, NRC Resident Inspector (w/a)
Mr. J. Beall, NRC Senior Resident Inspector (w/a)
NRC Document Control Desk (w/a) 8703030333 B61230 12DR ADOCK 0500 2
[E D l t
l United States Nuclear Regulctory Consnission Mr. Steward D. Ebneter, Director Inspection Report 50-412/86-32 Page 2-COMONWEALTH OF PENNSYLVANIA ')
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sS:
COUNTY OF BEAVER
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On this 8/dday of
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/fh _, before me, a Notary Public in and for sald Commonwealth and County, personally appeared J. J. Carey, who being duly sworn, deposed and said that (1) he is Senior Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoiilg Submittal ~ on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge.
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Notary PuTITc sen 1. i.u;.;c. war y,suc EPPIEP0ltT 60Ac. a(AYER COUNTY.
EY C08Ml3810R CPitE3 GCf. 23,legg Rubw, Penochenia Associatios of Netyk 1
Notice of Deviation 86-32-02 As a result of the inspection conducted on October 20-24, 1986, the following deviation from a conmitment to the NRC, contained in the Beaver Valley Power Station Unit 2 FSAR, was identified.
FSAR paragraph 14.2.12.15.1, entitled " Recirculation Spray Systen Pumps and Controls Test," states under " Test Methods," iten 3, that "Available net posi-tive suction head will be determined."
Contrary to the above, as of October 24, 1986, preoperational test procedure P0 2-13.01, " Recirculation Spray System Pumps and Controls," does not determine available net positive suction head.
Response
The Deviation, as stated in the NRC Inspection Report, is concerned with the lack of a "detennination" by calculation of available Net Positive Suction Head (NPSH) in test procedure P0 2.13.01.
However, upon further discussion with the NRC, an additional concern was raised as to whether the Recirculation Spray System (RSS) Pumps should be tested to demonstrate required NPSH for the pumps.
The NRC considered that demonstrating proper punp operation by showing no cavi-tation at required NPSH would validate the field installed pump configuration to be in accordance with design for this concern.
The BVPS-2 Startup Group has discussed these concerns with a Stone and Webster Pump Consultant and has determined that such testing cannot be practically performed in the field.
The design of the RSS Pumps and the construction of the RSS are such that the vertical distance between the centerline of the inlet nozzle suction pipe to the punp can and the centerline of the punp first stage impeller is equal to the pump required NPSH.
Since the centerline of the inlet nozzle is located below the containment floor, it would not be possible to perform required NPSH testing with a measurable water level in the sump.
Even if the test were conducted with the water level at the centerline of the inlet nozzle, the available NPSH would still exceed required NPSH.
A second complicating problem to denonstrating required NPSH is the phenomenon of vortexing.
Stone and Webster has determined that a delay of 630 seconds, af ter initiation of a Containment Isolation Phase B signal, is required before start of the RSS pumps to ensure that the containment water level is at least at an elevation of 693.8 feet.
The water level of elevation 693.8 feet has been verified by sump hydraulic model testing as acceptable for absence of vortexing.
These test results were based on the water velocities that would occur if the containment floor surf ace were flooded. Test procedure P0 2.13.01 and future surveillance tests will be conducted with the use of a tenporary dam which will allow only a snall area of the containment floor to be flooded.
This smaller area will change the water velocities in the sump.
The BVPS-2 Startup Group considers that test procedure P0 2.13.01 should be conducted with an initial water level at elevation 696.5 feet to ensure that vortexing does not occur during the field pump performance test.
.s BVPS-2 considers that the adequacy of the design and the reliability of the RSS Pumps have been demonstrated via an extensive vendor test program and hydraulic model testing for the pumps and the containment sump configuration, respective-ly. These demonstrate that there exists sufficient margin between the required NPSH of the RSS Pump and the available NPSH of the RSS that will ensure pre-dictable and reliable pump operation in the unlikely event of an accident.
Further information is available in the ' detailed responses to the NRC relative to this issue provided in previous interrogatories, BVPS-2 FSAR Q440.35 and Q480.2. Also, discussion of available NPSH to the RSS Pumps is provided in the BVPS-2 FSAR, 6.2.2.3.2.
To eliminate confusion and an unrealistic testing requirement in the BVPS-2 FSAR test abstract, 14.2.12.15.1, " Recirculation Spray System Pumps and Con-trols Test," Test Method Iten 3 will be deleted. This revision will be submit-ted by December 31, 1986 and incorporated in the next FSAR aumendment which will be issued in March 1987.
Full compliance will be achieved at that time.