IR 05000220/1988201

Provides Summary of Significant Findings in Advance of Insp Rept 50-220/88-201,so That Appropriate Corrective Actions May Be Factored Into Restart Planning Activities.Issues That Must Be Resolved Before Sys Declared Operable Listed

ML20205M497
Person / Time
Site:	Nine Mile Point
Issue date:	10/26/1988
From:	Varga S Office of Nuclear Reactor Regulation
To:	Mangan C NIAGARA MOHAWK POWER CORP.
Shared Package
ML17055E349	List: IR 05000220/1988201
References
NUDOCS 8811030125
Download: ML20205M497 (4)

Text

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• % ,\ UselTED STA788 I NUCLEAR REOULATORY COMMISSION I

{ waamesoroes, o. c, seems l

• • • • • / October 26, 1988 Docket No. 50-220

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f Mr. C. !

Senior Vice President l Miagara Mohawk Power Corporatten  !

301 Plainfield Road i Syracuse, New York 13212 l

Dear Mr. Mangan:

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$UBJECT: SAFETY $YSTEM FUNCTIONAL INSPECTION ($$FI) RESYART FIN 0!NG$ l (REPORT 50-220/88-701) i i

A special announced team inspection of the activities at Nine Mile Point 1  !

Nucluar Generating Station was conducted by NRC headouarters and Region I staff f during the period September 12, 19P8 through October 7. 1988. The team discussed  !

the inspection findings with you and members of your staff during the course of i this inspection and at the exit meeting on October 7, 1988 This letter providas  ;

a summery of the significant findings in advance of the inspection report I (50-220/88-201) so that appropriate corrective actions may be factored into your  !

restart planning activities. [

1. The following system functional issues must be resolved before the affected  !

systerts are declared operable: l i

a. The Technical Specification limiting condition for operatinn (LC0)  !

which allows continued plant operations for up to seven days with an inoperable core spray sparger may not La appropriate. The analyses (NEDC31444P) conducted in accordance with 10 CFR 50.46 and i 10 CFR 50. Appendix K assumed two core spray spargers were available  !

to support the complete spectrum of loss of coolant accidents (LOCAs). l This LC0 appears to be less conservative than any analyzed single i active failure to the core spray system.

l b. Analyses were inadequate and testing of the core spray system did not demonstrate system perfomance as described in the licensing ,

documents for the following reasons: l (1) Net positive suction head (NPSH) for the pumps may not be f adequate to support the flows expected during large break [

LOCAs with containmerit sprays in operation, j (2) Vortexing analyses did not account for the interactive  !

effects of the two pamp suctions which are in close proximity to each other.

(3) System resistance curves did net account for all the components in the system.

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/ Enclosure 1 l

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, i 1 (4) System pump curves did not appear to be controlled or validated i

by testing over the full range of expected flows.  ;

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(5) Potential flow diversion from the reactor through the combined a pump discharge relief valve was not considered in any  ;

analyses.

c. The core spray system alarm setpoints and procedural responses I appeared inappropriate for the following reasons: i (1) The core spray pump low suction and discharge pressure alams were set at values that would be expected to occur

'i during large break LOCAs and the alam response directed that the affected pumps be secured even though the system ,

remained operable. t l (2) The strainer high differential pressure alam was set at a value that would be expected to occur during large break LOCAs I and the alam response directed that the affected line be

secured even though the system remained operable.  !

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(3) The core spray high pressure alarm was set at a pressure that j would be received if the relief valve failed to open prior to !

l system injection and the alam response was to secure both t

< sets of pumps in the line. This single failure could disable i i

both pump sets ir a sparger. J t

! d. The Emergency Operating Procedures (E0Ps) did not appear to f provide adequate guidance for core spray system operation in r the following instances. ,

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! (1) The procedure for filling the torus vsing the core spray  !

i system would not work if the core spray system initiation  !

i signal was present or the system was in operation. Both  !

of these conditions could be expected during E0p scenarios, e (2) The graphs for cautioning whether pump suction pressure was [

close to the minimum allowable NPSM or vortexing limits were -

I for individual pumps, but the available flow indication mas on the comon discharge line for both pump sets. [

! (3) The limitations for RPV level indication failed to identify that some level instruments shared a comon RPV tap with the

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core spray system and would be unreliable during core spray ,

cperation, j l

! e, Analyses were inadequate and testing of the high pressure coolant I

infection (HPCI)/Feedwater (FW) system did not demonstrate system  !

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perfomance as described in licensing documents for the following (

l reasons:  !

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(1) Independent calculations perfomed by the tear. Indicated i that the condensate and booster pumps would not provide }

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i the flow specified in the Technical Specification Bases .

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at a reactor pressure of 450 psig because of shutoff head limitations.

(21 No analyses existed to support the FSAR statement that electric power for the HPCI/FW system would be available i from Bennets Bridge upon a loss of nomal site power to .

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the pumps. The team was concerned that the ADS system would initiate before the HPCl/FW system would be available.

(3) No analysis was provided to show that necessary water levels in the condensate storage tank could be adequately transferred to the hotwell without vacuum to support .

HPC!/F) pumps flows. (4 (4) The pump curves used for HPC!/FW testing appeared to be uncontrolled, limited to the motor-driven feedwater pumps (excluding the booster and condensate pumps), and f ailed to account for a modification which changed i impellers to ones with different operating characteristics, f. The design of the core spray keep fill system did not appear to -

prevent water hamer throughout the system and existing testing did not ensure that water hamer would not occur under certain LOCA conditions, g. The use of "Fumanite" to repair HPCI/FW manua) isolation valve 30-10 appeared to be excessive, perforined without adequate analyses and may not be a suitable repair to support plant startup.

h. The range of control room flow instrumentation for the core spray system was not adequate to measure the full t-ange of expected system flows.  !

1 The motor-driven feedwater purps were not designed to support l the frequent starting that may be required by HPC!/FW system reactor water level control modifications and operating proce-  ;

dures.

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?. The following progressnatic concerns are provided for your early initiation of co'*rective action before the inspection report is issued and your evalua-

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f tion of whether they require correction before chancing operational modes: i a. Examples were found where Surveillance Test Program data collection. I results review and acceptance value detemination would not adequately

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support system operability decisions.

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I b. Internal responses to industry infomation such as NRC Infomation [

Notices, GE Service Infomation Letters and INP0 infomation did ,

not always appear to be timely or sufficiently researched, j

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c. Investigation into problems and assessment of reportability in accordance with 10 CFR 50.72 and 10 CFR 50.73 did not always appear to be adeoutte.

d. The written periodic maintenance prooram did not include all recomended maintenance activities Of the eautpoent vendor ,

manuals or the actuai periodic maintenance being perforwed on safety systems during the outage.

e. Non-licenses operator training did not include a programed topic >

for the det+rmination of valve position locally. This issue was previously identified during Inspection Report 50 410/88-10 ,

for Nine Mile Point. Unit 2.  ;

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f. The QA audit program concentrated on programatic issues and would not necessarily be able to identify significant technical issues  :

with safety system operation, testing, design or maintenance.

g. Several material deficiencies were identified by the team during their walkdown of the systems which had not been previously identi- '

I, fled, evaluated and prioritized for correction.

The findings listed above are the more significant concerns identified 9uring the inspection and provide r:either a complete list of inspection conce'ns nor any of the strengths identified by the inspection team. A complete l'st of '

inspection findings will,be provided in Inspection Report 50-220/88-7J1.

In anticipation of the inspection report, please respond with your eroposed

corrective actions to the individual functional concerns listed abe.ve in l paragraph 1. This written response will be considered as part of our review i of your readiness to restart. Additionally, a meeting will be scheduled durino l j the week of Nogeeber 14, 1988 in our Rockville, MD office to discuss your pre.

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liminary plans. Please remember that the 55FI only concentrated on the HPC!/FW  ;

and core spraf systems. At the NRC meeticg please be prepared to discuss the t other systems you will review and the methods, schedule and personnel you will (

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use to accanplish the reviews.

, I Si cerely, j l

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Q arga, Dirtet l

t Division of Reactor % 1 ts I/!!

0?fice of Nuclear Reactor Regulation

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