05000265/LER-1997-003-04, :on 970321,2B Core Spray Room Cooler Fouled Due to Hydrolyzing Debris.Cs Room Cooler Was Cleaned Under Nwr 960039336-01 & Qctp 1110-12, ECCS Room Cooler Trending Program, Has Recently Been Rewritten

:on 970321,2B Core Spray Room Cooler Fouled Due to Hydrolyzing Debris.Cs Room Cooler Was Cleaned Under Nwr 960039336-01 & Qctp 1110-12, ECCS Room Cooler Trending Program, Has Recently Been Rewritten

ML20140C989
Person / Time
Site:	Quad Cities
Issue date:	04/15/1997
From:	Peterson C COMMONWEALTH EDISON CO.
To:
Shared Package
ML20140C985	List: 05000265/LER-1997-003-04, :on 970321,2B Core Spray Room Cooler Fouled Due to Hydrolyzing Debris.Cs Room Cooler Was Cleaned Under Nwr 960039336-01 & Qctp 1110-12, ECCS Room Cooler Trending Program, Has Recently Been Rewritten
References
LER-97-003-04, LER-97-3-4, NUDOCS 9704220051
Download: ML20140C989 (4)

LER-1997-003, on 970321,2B Core Spray Room Cooler Fouled Due to Hydrolyzing Debris.Cs Room Cooler Was Cleaned Under Nwr 960039336-01 & Qctp 1110-12, ECCS Room Cooler Trending Program, Has Recently Been Rewritten

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv), System Actuation
2651997003R04 - NRC Website

text

o LICENSEE EVENT REFORT (LER)

Form Rev. 2.0 Fadity N:me (1)

Docket Number (2)

Page (3)

Quad Citi:s' Unit Tw'o 0l5l0l0l0l2l6l5 1 l of l 0 l 4 Title t4) 2 B Core Spray Roorn Cooler Fouled Due To Hydrolyzing Debris Ev:nt Date (5)

LLR Number (6)

Report Date (7)

Other Facihties involved (8)

Month Day Year Year Sequential Revision Month Day Year Facibry Docket Numberts) 4 Number Number Names 0l5l0l0l0l l

l 0l3 2l1 9l7 9l7 0l0l3 0l0 0l4 1l5 9l7 0l5l0l0l0l l

l OPERATING THis REPORT is SUBMrITED PURSUANT TO THE REQUIREMENTS OF 10CFR MODE (9)

(Check one or more of the following) (11) 4 20.402(b) 20.405tc) 50.73(a)(2)(iv) 73.7)(b)

POWER 20.405(a)(1)(i) 50.36(c)(1)

- 50.73(a)G)(v) 73.71(c)

LEVEL

- 20.405(a)(1)(ii) 50.36(c)G) 50.73(a)C)(vii)

Other (Specify (10) l l

0

- 20.405(a)(1)(iii) 50.73(a)G)0) 50.73(a)C)(viii)(A) m Abstract 20.405(a)(1)0v) x 50.73(a)G)0i) 50.73(a)C)(viii)(B) below and in 20.405(a)(1)(v) 50.73(a)G)0ii) 50.73(a)G)(x)

Text)

LICENSEE CONTACT FUR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE Ch:.rles Peterson, Regv!atory Affairs Manager, ext. 3609 3

0l9 6l5l4l-l2l2l4l1 COMPLLTE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE

SYSTEM COMPON ENT MANUFACIURER REPORTABLE

CAUSE

SYSTEM (x)MPONEt4T MANUF#CrV RER REPORTABLE

'!D NPRDS TO NPRDS I

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I SUP 'LEMENTAL RDORT EXPEL.it.u tl4)

Expectoi!

Mumb Day Year Subminsk>n lYES Of yes. canplete EXPECTED SUBMIS$10N DATE)

~k"]NO Date (15) l l

l ABSTRACr (lamit to 1400 spaces. i.e., appronunniely firteen sinsk space typewnuen imes) (16)

ABSTRACT:

On 032197, significant fouling was discovered in the 2B Core Spray Room Cooler (CSRC) during the a pre-cleaning inspection. This condition may have existed from June 1996.

During this time period the 1/2 Emergency Diesel Generator (EDG) had been made inoperable for planned maintenance under a 7 day' Limiting Condition for Operation (LCO). Although the normal power supply for the 2A CS pump was available, the 1/2 EDG which is the emergency power supply was unavailable and the CS Technical Specification requirement was not met.

Assuming a design basis accident both CS pumps were inoperable unknowingly for a period of approximately 6 days.

The room cooler was declared inoperable and at 1952 hours0.0226 days <br />0.542 hours <br />0.00323 weeks <br />7.42736e-4 months <br /> a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> ENS phone call was made.

The apparent cause of the event was a plugged cooler caused by debris stirred up by hydrolyzing performed during Q2R13 on the EDG Cooling Water System. A contributing cause of the event was the lack of proper trending of the differential pressure (dP) data taken on the Emergency Core Cooling System (ECCS) Room Coolers.

Corrective actions completed include cleaning of the 2B CSRC and the other Unit 2 ECCS Room Coolers.

Unit 1 Room Coolers were cleaned less than a year ago. A new procedure will address future trending and analysis of room cooler dP and flow data. The risk to the health and safety of the public is reduced with the use of Station Blackout Power.

LER265\\97\\003.MTF 9704220051 970415 PDR ADOCK 05000265 S

PDR

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e 7j LICENSEE EVEt(T REPORT (LER) TEXT CONTINUATION Form Rav. 2.0 I'ACILrrY N AME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

'PAGE (3)

Year Sequential Revimon Number Number l Quad CitiIs Unit Two 0l5l0l0l0l2 6l5 9l7 ol0 2 lOFl 0 l 4 0l0l3 i

TEXT Energy industry Idera26 cation System (E!!$) codes are identi6ed in the text as L(X)

PLANT AND SYSTEM IDENTIFICATION

General Electric - Boiling Water Reactor - 2511 MWt rated core thermal power.

EVENT IDENTIFICATION:

28 Core Spray Room Cooler Fouled due to Hydrolyzing Debris.

A.

CONDITIONS PRIOR TO EVENT

Unit: Two Event Date: March 21, 1997 Event Time:

1620 Reactor Mode:

4 Mode Name:

COLD SHUTDOWN Power Level:

0

}

This report was initiated by Licensee Event Report 265\\97-003.

Cold Shutdown (4) - Mode switch in Shutdown position with average reactor coolant temperature 5212 degrees F.

B.

EVENT DESCRIPTION-On 032197, System Engineering performed a pre-cleaning inspection on the 2B Core Spray (CS)[BM) Room Cooler (CSRC)[CLR). During that inspection significant fouling of the first (lower elevation) pass of the 8-pass heat exchanger was noted.

10 of 18 tubes were completely plugged with corrosion products, with 6 additional tubes being significantly but not completely plugged in this pass.

With this many tubes plugged, the 2B CSRC was declared inoperable.

l Historical differential pressure (dP) trending data reveals that this condition of fouling may have existed from June 1996. Differential Pressure on the 2B CSRC exceeded the set high dP limit in June 1996 and then returned to normal levels the following month.

During this time period, the 1/2 Emergency Diesel Generator

~

(EDG)[EK] had been made inoperable for planned maintenance under a 7 day Limiting Condition for Operation (LCO). Although the normal power supply for the 2A CS pump i

4 was available, the 1/2 EDG which is the emergency power supply was unavailable and the CS Technical Specification requirement was not met. Assuming a design basis accident both CS pumps were inoperable unknowingly for a period of approximately 6 days.

On 032197 at 1952 hours0.0226 days <br />0.542 hours <br />0.00323 weeks <br />7.42736e-4 months <br /> a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> ENS phone call was made.

i The 1/2 EDG was also inoperable in January 1997 for 1 day.

System Engineering instructed maintenance to clean the fouled cooler under existing NWR 960039336-01.

i The Unit 1 Emergency Core Cooling System (ECCS) Room Cooler dPs were also reviewed in reference to this event.

There is no indication that any of the Unit 1 ECCS Room Coolers are experiencing the same type of fouling.

l trausteme3.wrr

2 LICENSEE EVENT REPORT (LER) TEXT COffrINUATION Form Rev. 2.0

@CILfrY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

Year Sequential Revision Number Number Quad Cities Unit Two 0l5l0l0l0l2l6l5 9l7 0l0 3 lOFl 0 l 4 0l0l3 TEXT Energy industry identification System (E!!S) codes are identified te the text as lXX)

C.

APPARENT CAUSE OF EVENT:

The root cause of this event was inadequate flushing of debris following the hjdrolyzing during Q2R13. The fouling of the 2B CSRC was caused by debris loosened by hydrolyzing performed on the Unit 2 EDG Cooling Water [LB] piping during Q2R13 refuel outage.

This hydrolyzing was required due to the plugging experienced in the system. During that time, pipe corrosion products, clam shells, sticks and debris were dislodged by the hydrolyzing, but were not flushed from the system.

During Q2R13 all the ECCS Room Coolers had to be cleaned and inspacted twice because of the amount of debris found from the hydrolyzing. To assure that debris flushed from the system during Q2R13 was removed, the EDG Cooling Water System was run at full flow for several days before the second set.of cleanings were performed on the ECCS Room Coolers.

A contributing cause to this event was the lack of proper trending and analysis of the dP data, i.e. a cognitive personnel error, throughout the cycle.

In October 1996, during an NRC inspection it was discovered that trending of the Room Cooler dP was not performed for about a year.

During this period the first adverse trend on the 2B CSRC appeared.

If trending had been performed properly then a PIF or a ultrasonic flow reading would have followed up the suspect dP reading.

In October 1996, a review of the previous dP data was performed but at that time the high dP in l

June 1996 was not thought to be significant.

Ihe dP was only 0.8 psi above the high dP limit and it returned to normal the next month.

D.

SAFETY ANALYSIS OF EVENT:

)

Previous calculation on the ECCS Room Coolers have shown that the 2B CSRC can meet its design cooling function with a flow as low as 30 gallons per minute at 95 degree Fahrenheit (F) river water temperature.

Direct correlation from dP to flow does not exist due to the fact that fouling results in a variable orifice. Therefore, it is impossible to know what the actual flow was through the cooler at the time of the adverse fouling.

With both loops of Core Spray inoperable, Low Pressure Cooling Injection (LPCI) mode of Residual Heat Removal (RHR) system would be the only source of water into the core. Calculations show that the CS Room temperature without any cooler will rise continually.

The equipment qualificathn (EQ) temperature of 185 degrees F will be reached in approximately 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />. Therefore, we can assume that the B CS loop would operate for the first day.

Station Blackout (SBO) Diesels would have been available to supply power to the 2A CS loop before the EQ temperature was reached in the 2B Core Spray Room. Therefore, the risk to on-site personnel and to the health and safety of the public is minimized.

ixaustmoo3.wer

i LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Form Rce. 2.0 IRCILTTY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

Year Sequential Revision Number Number Quad Cities Unit Two 0l5l0 0l0l2 6l5 9l7 0l0l3 0l0 4 lOFl 0 l 4 TEXT Energy industry identification System (EHS) codes are identifim in the text as (XX) 1 E.

CORRECTIVE ACTIONS

Corrective Actions Completed The 2B CS Room Cooler was cleaned under NWR 960039336-01.

QCTP 1110-12, "ECCS Room Cooler Trending Program," has been recently written to give direction to the System Engineer on how to trend and analyze Room Cooler dP and flow data.

The 2A CS, Unit 2 High Pressure Coolant Injection (HPCI), 2A and 2B RHR Room Coolers have been cleaned and inspected during Q2R14.

Similar fouling of a lesser magnitude has been seen in some of these coolers.

Both 2A and 2B RHR Room Coolers had 10-11 tubes partially plugged and are allowed 32 tubes completely plugged. The 2A Core Spray had all tubes completely clear of debris. The HPCI Room Cooler has flow indication which assured us that it could perform its design function.

Corrective Actions to be Completed A predefine (electronic reminder) is being set up in Electronic Work Control System (EWCS) to track completion of QCTP 1110-12. (NTS 254-201-96-284901)

Modification Design Change Package (DCP) #9500060 is being installed during Q2R14 to add flow indicators to the RHR and CSRCs. These flow indicators will assist engineering to ensure that these coolers are able to perform their design function.

(NTS # 265-180-97-00301; Mod Design Engineering.)

Modification DCP 95000L is also planned to be installed on Unit 1 during Q1R15.

(NTS # 265-180-97-00302; Mod Design Engineering)

F.

PREVIOUS EVENTS:

A search was performed for a 3 year history of Level III investigations with the keyword of clogged / plugged. The following events were found:

LER 2-92-007 2A and 2B RHR Room Coolers plugged due to. insufficient cleaning.

I LER 1-94-007 HPCI Restricting Orifice Found 95% Plugged with Weld Slag.

LER 1-94-011 During Scram Timing, Control Rod Drive Failed to Scram due to Pipe Plug Inserted into Solenoid Valve PIF 96-3272 Toxic Gas Analy2.er Sample Flow Low Because of Worn Out Pump or Line Restrictions.

G.

COMPONENT FAILURE DATA

NONE 1XR265\\97WO3.WFF