JAFP-99-0129, Submits Comments on Technical Review of Draft Info Notice Describing Unanticipated Reactor Water Draindown at Quad Cities Unit 2,ANO & FitzPatrick

Submits Comments on Technical Review of Draft Info Notice Describing Unanticipated Reactor Water Draindown at Quad Cities Unit 2,ANO & FitzPatrick

ML20205M259
Person / Time
Site:	Arkansas Nuclear, Quad Cities, FitzPatrick
Issue date:	04/09/1999
From:	Michael Colomb POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
JAFP-99-0129, JAFP-99-129, NUDOCS 9904150195
Download: ML20205M259 (6)

Text

J mes A. FitzPatric,,

Nuch r Pow:r Pilnt 268 Lp' e Road P.O. Box 41 Lycoming, New York 13093 315 342 3840 h NewYorkPower uicnaei a. Coiome

& Authority site executive of<>cer April 9,1999 I JAFP-99-0129 United States Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, D.C. 20555

Subject:

James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 i Technical Review Of Draft Information Notice Describing The Unanticipated Reactor Water Draindown At Quad Cities Unit 2, Arkansas Nuclear One And l FitzPatrick j

Dear Sir:

Our staff has reviewed the subject Draft Information for technical accuracy. Our review did not address the events at Quad Cities 2 or Arkansas Nuclear One. Our comments are delineated below.

Description of Circumstances: FitzPatrick General Comment:

The draft Information Notice only addresses the availability of the reactor level instruments identified in the outage risk assessment. A review of Surveillance Test 40X (Daily Shutdown Surveillance and Instrument Check) indicates that, with the exception of the l Refuel Water Level Indication, all reactor level instruments remained operable. I Furthermore, a review of the Root Cause Analysis interview notes for this event confirmed that the Nuclear Control Room Operator (NCO) was aware that reactor level was always 224.5 inches by observing " narrow and wide range instruments".

i The draft Information Notice only addresses the two levelinstruments identified in the l outage risk assessment, therefore, our comments below correct factual errors within that k s !

context. It would be appropriate to revise the draft Information Notice to acknowledge b that essentially the full compliment of reactor water level instrumentation was available to confirm that reactor level never fell below 224.5 inches.

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, United Statss Nuclear Regulatory Commission Pag s Attn: Document Control Desk

Subject:

Technical Review Of Draft Information Notice Describing The

, . . Unanticipated Reactor Water Draindown At Quad Cities Unit 2, i Arkansas Nuclear One And FitzPatrick The first paragraph, second sentence reads:

" Operators were controlling the reactor vessel level to approximately 350 inches..."

This sentence is correct as written because an approximate value is given. However, later in the document reactor level values are nct referred to as approximate values. The actual value stated in the root cause analysis for this event was 357 inches. The precise level values are being provided so that a consistent convention (actual vs. approximate) can be maintained with respect to reactor level values.

The first paragraph, last sentence reads:

"One was the wide-range levelindicator (which provided indication up to the top of the reactor vessel) and the other was a narrow-range indicator which was off-scale high."

In f act, the second indicator was also a wide range indicator (RHR Interlock Level Indicator, range: -150 inches to + 200 inches). The Draft Information Notice correctly states that this indicator was off scale high.

The second paragraph, first sentence reads:

"In order for the wide range level indicator to remain operable with..."

The word " operable" should be changed to "available". The permanent reference column for this instrument was replaced with a temporary column to maintain this instrument available for the purposes of shutdown risk management.

The second paragraph, fifth sentence reads:

"This action had the effect of reducing the actual water level from 350 inches to 250 inches."

These level values are approximate. The actual values stated in the event root cause analysis are 357 inches and 255 inches respectively.

The second paragraph, sixth sentence reads:

"During the same time period, the operators were also in the process of filling and venting the feedwater piping which also affected reactor water level."

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, United States Nuclser Regulatory Commission P:ga Attn: Document Control Desk

Subject:

Technical Review Of Draft information Notice Describing The

. Unanticipated Reactor Water Draindown At Quad Cities Unit 2, Arkansas Nuclear One And FitzPatrick l This sentence is not completely accurate. While it is correct that during the same time period, the operators were also in the process of filling and venting the feedwater piping, our root cause analysis was not able to confirm that reactor inventory was actually affected by this evolution. A more accurate sentence would be:

"During the same time period, the operators were also in the process of filling and venting the feedwater piping which was recognized as having the potential to affect water level."

The second paragraph, seventh sentence reads:

"Once the normal reference leg piping had been reinstalled and the reference leg began to refill, the indicated level decreased from 350 inches to the actual level of 250 inches."

These level values are approximate. The actual values stated in the event root cause analysis are 357 inches and 255 inches respectively.

The second paragraph, last sentence reads:

"The second level instrument (the narrow-range level indicator) which does not come on-scale until the level goes below 224 inches remained off-scale high."

This sentence should read:

"The second level instrument, which does not come on-scale until the level goes below 200 inches, remained off-scale high."

The third paragraph, third sentence reads:

"The 100-inch error represented approximately 15,000 gallons of water."  !

The root cause analysis for this event identified an increase in hotwell level of 8.5 uches which corresponds to 14,067 gallons. It can be inferred that this hotwell levelincrease may have been due to the approximate 100 inch reduction in vessellevel during the event, however a rigorous mass balance was not performed to confirm this inference. There may have been other water sources to the hotwell which were not germant the root cause analysis.

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, United States Nuclear Regulatory Commission pig 2 Attn: Document Control Desk

Subject:

Technical Review Of Draft Information Notice Describing The

. . Unanticipated Reactor Water Draindown At Quad Cities Unit 2, Arkansas Nuclear One And FitzPatrick  !

l The third paragraph, last sentence reads:

"In addition, the drain-down would have been limited by an automatic isolation of I the draindown path, which would have occurred at 177 inches above the TAF."

The actualisolation would have occurred at 179.6 inches (Tech Spec require > 177  !

inches). A more appropriate sentence would be: {

i "In addition, the drain-down would have been limited by an automatic isolation of the draindown path, which would have occurred prior to vessellevel reaching 177 inches above TAF." {

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The fourth paragraph, first sentence reads:

"The licensee's review of the event identified weaknesses in the operator's knowledge of the reactor assembly process and weaknesses in the plant risk assessment program."

The Root Cause Analysis for this event also identified insufficient detailin the reactor I reassembly procedure because the level instrument which was rendered unavailable was not identified by the component identification number; therefore, there was no explicit prompt to indicate the instrument would be rendered unavailable. This sentence should read: ,

1 "The licensee's review of the event identified weaknesses in the operators knowledge of the reactor assembig process, weaknesses in the explic?t detailin the reactor assembly procedure and weaknesses in the plant risk assessment process."

The fourth paragraph, second sentence reads: i

" Contrary to the assumption in the plant risk analysis that two reactor level indicators were available, only one, the wide-range indicator, was able to provide  !

levelindication above 224 inches."

i This sentence infers that both instruments identified in the risk assessment were thought to be on scale above 224 inches. This is not accurate. The risk assessment recognized 1 that one of the two instruments would not come on-scale until reactor level fell below 200 inches. A more appropriate wording for this sentence would be:

" Contrary to the assumption in the plant risk analysis that two reactor level indicators were available, only one was able to confirm that reactor level remained above 200 inches."

, United States Nuciss:r Regulatory Commission Prg3 Attn: Document Control Desk

Subject:

Technical Review Of Draft Information Notice Describing The

. . Unanticipated Reactor Water Draindown At Quad Cities Unit 2, Arkansas Nuclear One And FitzPatrick The fourth paragraph, third sentence reads:

"When the reference leg on the wide-range instrument was disassembled and drained, it was rendered inoperable." )

This sentence should read:

"When the reference leg on the wide-range instrument was disassembled and drained, it was rendered unavailable."

The fourth sentence, fourth paragraph reads:

"The second instrument, the narrow-range indicator, was pegged off-scale high and remained that way throughout the event because the level never dropped below 224 inches." '

This sentence should read:

"The second instrument was pegged off-scale high and remained that way throughout the event because tha level never dropped below 200 inches."

The fourth paragraph, last sentence reads:

" Proposed corrective actions included procedural enhancements to address the loss of level indication during reactor disassembly and reassembly and providing for an alternate means of level indication."

This sentence should read:

" Proposed corrective actions included procedural enhancements to ensure that reactor level instrumentation credited by the outage risk assessment, remains i available during reactor disassembly and reassembly." i Discussion:

1 The second paragraph infers that reductions in experienced plant staff, shorter outage times and increased staff work loads increases the likelihood of personnel errors. The third paragraph acknowledges that the extent to which these f actors contributed to the events in the draft Information Notice 's unknown. The Root Cause Analysis for the event at FitzPatrick did not identify any of the factors as a contributing cause. l

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, United Stctes Nuclear Rsgulatory Commission P2ga Attn: Document Control Desk

Subject:

Technical Review Of Draft Information Notice Describing The l , . Unanticipated Reactor Water Draindown At Quad Cities Unit 2, Arkansas Nuclear One And FitzPatrick l If you have any questions, please contact Mr. Robert Steigerwald at (315) 349-6209.

l Very truly yours, e

MICHAEL J. COLOMB Site Executive Officer j l

MJC:MA:las cc: U. S. Nuclear Regulatory Commission Regional Administrator 475 Allendale Road King of Prussia, PA 19406 U. S. Nuclear Regulatory Commission Office of the Resident inspector P.O. Box 136 Lycoming, NY 13093 U. S. Nuclear Regulatory Commission Mr. J. Williams, Project Manager Project Directorate l Division of Licensing Project Management Mail Stop 8C2 Washington, DC 20555 l

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