ML17229A384

LER 97-002-00:on 970518,containment Sump Debris Screen Was Not IAW Design Due to Gaps in Screen Encl.Performed SER to Document Containment Sump Design requirements.W/970617 Ltr

ML17229A384
Person / Time
Site:	Saint Lucie
Issue date:	06/17/1997
From:	Benken E, Stall J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-97-157, LER-97-002-03, LER-97-2-3, NUDOCS 9706230211
Download: ML17229A384 (13)

Text

~ CATEGORY lg REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9706230211 DOC.DATE: 97/06/17 NOTARIZED: NO DOCKET FACIL:50-'389 St. Lucie Plant, Unit 2, Florida Power E Light Co. 05000389 AUTH. NAME AUTHOR AFFILIATION BENKEN,E.J ~ Florida Power !'ight Co.

STALL,J.A. 'Florida Power 6 Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 97-0 02-00:on 970518,containment sump debris screen was not IAW design due to gaps in screen encl. Performed SER to document containnment sumo design requirements.W/970617 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-3 PD 1 1 WIENS,L. 1 1 INTERNAL: ACRS 1 1 EQD/NgD/ AB 2 2 AEOD/SPD/RRAB 1 1 ILE CENTE 1 1 NRR/DE/ECGB 1 1 NRR D /EE B 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB 1

1 1

1 1

1 1

1 NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN2 FILE 01 l,l 1

1 1

1 1

1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 1 1 NOAC POOREgW. 1 1 NOAC QUEENER,DS 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT. 415-2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL 25

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Florida Power 5 Light Company, 6501 South Ocean Drive. Jensen Beach, FL34S57 June 17, 1997 L-97-157 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Re: St. Lucie Unit 2 Docket No. 50-389 Reportable Event: 97-002 Date of Event: May 18, 1997 Containment Sump Debris Screen Not in Accordance With Design The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, J. A. Stall Vice President St. Lucie Plant JAS/EJB Attachment cc: Regional Administrator, USNRC Region II Senior Resident Inspector, USNRC, St. Lucie Plant IIIIIIIIIIIIIIIII,IIIIIIIIIIIJIIIIIIIIIII noooj Q 970b2302i.i 970bi7 PDR ADGCK OMQOSBV, S PDR I an FPL Group company

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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB No. 31604104 EXPIRES 04/30/OS (4-9S)

ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATOR r INFORMATION COLLECTION REQUEST: 60.0 HRS. REPORTED LESSON LEARNED ARE INCORPORATED INTO THE UCENSING PROCESS AND F BACK To INDUS(RY. FORWARD COMMENTS REGARDING BURDEN ESTIMAT g LICENSEE EVENT REPORT (LER) To THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T-6 F33)

U.S. NUCLEAR REGIAATORY COMMISSION, WASHINGTON, DC 206660001 AND TO THE PAPERWORK REDUCTION PROJECT (31604104), OFHCE 0 (See reverse for required number of MANAGEMENTAND BUDGET, WASHINGTON, DC 20603.

digits/characters for each block)

FACIUTY NAME (1) DOCKET NUMBER (2) PAGE (3)

ST LUCIE UNIT 2 05000389 1 OF8 TITLE (4)

Containment Sump Debris Screen not in Accordance with Design due to Gaps in Screen Enclosure FACIUlYNAME DOCKETNUMBER DAY YEAR YEAR SEQUENTIAL REVISION MONTH DAY YEAR NUMBER NUMBER N/A FACIUTY NAME DOCKETNUMBER 05 18 97 97 002 00 06 17 97 N/A OPERATING MODE (9) 20.2201 (b) 20.2203(a) (2) (v) 50.73(a) (2)(i) 50.73 (a) (2) (viii)

POWER LEVEL (10) 000 20.2203 (0) (2) (i) 20.2203(a) (3) (n) 50.73(a) (2)(iii) 73.71 QTHER 20.2203 (0) (2) (iii) 50.36(c) (1) 50.73(a) (2)(v) Specify In Abstract below or In NRC Form 366A 20.2203(a)(2) (iv) 50.36(c) (2) 50.73(a) (2)(vii)

NAME TELEPHONE NUMBER Bnrdude Area Code)

Edwin J. Benken, Licensing Engineer (561) 467 - 7156 CAUSE SYSTEM COMPONENT REPORTABLE MANUFACTURER To NPRDS CAUSE SYSTEM COMPONENT MANUFACTURER To NPRDS BQ SCN N/A N MONTH DAY YEAR EXPECTED YES SUBMISSION (lf yes, complete EXPECTED SUBMISSION DATE). X No DATE (15)

ABSTRACT (Umit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On May 18, 1997, St. Lucie Unit 2 was in Mode 5 following refueling. Inspection of the containment sump determined that several openings existed in the sump debris screens which were in excess of design requirements. The openings would allow small debris to enter the containment sump which could potentially enter the recirculation flow stream during the recirculation phase following a loss of coolant accident. The screen enclosure was subsequently modified to be consistent with design requirements.

The modifications were completed prior to the Unit 2 startup and the containment sump was returned to operable status on May 22, 1997.

Gaps existed in the containment sump screen due to failure to properly implement and verify design requirements during initial construction. Lack of procedural guidance for performing periodic sump inspections contributed to the delay in identifying the sump, screen condition and previous inspection of the containment sump configuration was insufficient in scope to ensure identification of the existing deficiencies.

Corrective actions include: 1) A safety evaluation was performed to document the containment sump design requirements and changes were made to clarify the Updated Final Safety Evaluation Report. 2)

The containment sump screen was modified to meet the requirements of design documentation. 3)

Procedural guidance will be developed to enhance periodic inspection of the containment sump. 4) The St. Lucie Unit 1 containment sump screen will be inspected during the next Mode 5 outage of sufficient duration. 5) The event will be incorporated into the continuing training program at St. Lucie.

NRC FORM 366 (4-9S)

1 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSIO I4-95I

\ LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 2 OF 8 97 002 00 TEXT Iifmore space is required, use additional copies of NRC &rm 366AJ I17)

The Emergency Core Cooling System (ECCS) containment sump [EIIS:BQ] at St. Lucie Unit 2 is a large collecting reservoir provided to supply water to the Containment Spray (CS) [EIIS:BE) and Safety Injection (Sl) [EIIS:BQ) systems for long term recirculation following design basis accidents. The sump is located at the lowest floor elevation in containment (excluding the reactor cavity sump) and is shielded by vertically and horizontally mounted screens designed to prevent debris, generated as a result of an accident, from entering the safety injection and containment spray systems. Per the St.

Lucie Unit 2 Updated Final Safety Analysis Report (UFSAR), Section 6.2.2.2.3, the containment sump was designed in accordance with the recommendations of NRC Regulatory Guide 1.82, Revision 0.

A coarse outer trash rack is provided between the secondary shield wall vent openings to prevent clogging of the sump screening. The fine mesh filter screens completely enclose the ECCS suction lines.

The total vertical area of the sump screens ensures that the coolant velocity through the screens remains acceptable during recirculation. A fine mesh vertical screen is also provided in the sump to assure separation of the redundant ECCS suction lines.

On May 18, 1997, St. Lucie Unit 2 was in cold shutdown (Mode 5) following refueling. During an inspection of the ECCS containment sump, the sump screens were found to be in a degraded condition.

Specifically, during an inspection of the containment sump area as required by Technical Specification (TS) 4,5.2, the Resident NRC Inspector and FPL operational support personnel identified an opening that existed between the edge of the vertical divider screen in the containment sump and the outside screen panel which encloses the sump. The vertical divider screen is designed to provide independence for the two ECCS suction lines (Train A and B) by dividing the sump into two distinct suction areas.

Based on the inspection observations, FPL site engineering and maintenance personnel performed additional walkdowns of the containment sump screens in order to compare them with design requirements. The additional inspections confirmed that a gap of approximately 2 inches existed between the outboard end of the divider screen panel (panel 10) and the screen panel which formed the outside wall around the sump (panel 4). The inspections also identified an additional 3/8 inch gap and missing metal panel associated with the vertical divider as well as some small gaps associated with the upper horizontal screen components and shield wall divider. screen. The openings which were found were in excess of that which is allowed by design.

A Plant Change/Modification (PCIVI 97- 037M) was implemented to restore the containment sump debris screen to an acceptable configuration. All field work for the completion of this modification was completed in accordance with the requirements of the PCM and the integrity of the outer screen enclosure and the vertical divider screen was fully restored, The containment sump was returned to operable status at 0531 on May 22, 1997, prior to the Unit 2 startup.

NRC FORM 366A (4.95)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSIO I4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 3 OF 8 97 002 00 TEXT llfmore space is required, use additional copies of IVRC Arm 366AJ I17I The deficiencies associated with the containment sump divider screen were caused by a failure to properly implement the design requirements for the screen enclosure during initial system construction.

Plant design drawing 2998-G-797, Sheet 13, specifies full closure of the vertical seams associated with the sump divider screen. An approximate 2 inch gap at the outboard end of the divider screen panel existed because the design detail to extend and connect the divider panel to the outside screen panel was not properly implemented during the original construction of the sump enclosure. The omission of a metal panel in the divider screen wall, and several other small gaps found in the sump screen enclosure were also a result of inattention to detail during original system construction. Failure to identify the above deficiencies through as-built verification at the time of construction resulted in unnecessary operation outside the approved design.

Insufficient guidance contributed to a prolonged delay in identifying the construction inadequacies and component gaps associated with the containment sump debris screen. Specifically, the surveillance requirements for'performing the sump inspection did not require a detailed inspection of the sump screen enclosure for compliance with the UFSAR design basis. Technical Specification 4.5.2.e.2 requires a visual inspection of the containment sump to verify that subsystem suction inlets are not restricted by debris and that sump components show no evidence of structural distress or corrosion.

This inspection is performed every 18 months. There are no specific plant requirements to inspect for gaps in the debris screens or to verify that the physical condition of the screen enclosure is sufficient to prevent bypassing the filtering function.

In February of 1994, FPL performed an inspection and general configuration verification of the St. Lucie Unit 2 containment sump based on industry events documented in NRC Information Notice (IN) 89-77, Supplement 1 (December 3, 1993). The IN was issued to alert licensees of potential problems associated with debris found in containment emergency sumps and incorrect screen configurations. As a result of the inspection, several sump screen configuration deficiencies were identified and subsequently corrected, however, the 1994 inspection primarily focused on damaged or missing components and obvious configuration inadequacies. The inspection scope did not provide for a detailed as-built verification of design which could have identified the additional deficiencies described in this report. As a result, an opportunity for earlier detection of the containment sump screen deficiencies was missed.

This event is being reported pursuant to the requirements of 10 CFR 50.73 (a)(2)(ii)(B), as "any event or condition of the nuclear power plant... that resulted in the nuclear power plant being in a condition that was outside the design basis of the plant." The St. Lucie Unit 2 UFSAR provides a description of the containment sump and debris screen design.

NRC FOAM 366A I4.95)

4 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSIO

<4.95)

I g, LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 4 OF 8 97 002 00 TEXT /if more spaceis required, use additional copies of NRC Form 366Al <17)

Design&asis The St. Lucie Unit 2 UFSAR, Section 6.2.2.2.3, states that the design of the containment sump follows the recommendations outlined in Regulatory Guide 1.82, and includes the following:

a) A large capacity sump, enclosing the redundant suctions of the ECCS and the CS systems which are separated by approximately 15 feet is provided for continuous recirculation.

b) ... Where necessary, such as in the case of safety injection tank piping and charging lines, design provisions are made to protect the sump from the effects of piping failure.

c) The sump is located at the lowest floor elevation in the containment (exclusive of the reactor cavity sump) and is shielded by two screens; an outer trash rack, and a fine mesh filter. The fine mesh screens completely enclose the suction lines rising vertically above the floor elevation. The screen panels are rigidly attached to the sump walls by being welded to embedded plates. In turn, the screen sections are welded to each other. All piping that penetrates the screens is provided with boots connecting the pipe and screen, blocking any potential unfiltered flow path. With these design provisions... no fluid can reach the suction lines without being filtered by the fine mesh screens.

d) Drains from the various regions of the containment are directed to the sump via vent openings in the secondary shield wall. These vent openings have coarse screens acting as trash racks that prevent debris laden water from impinging on the fine screens.

e) Debris generated inside containment as a result of an accident will be confined between the primary and secondary shield wall. Debris is prevented from reaching the trash racks placed at the secondary shield wall vent openings ~ ~ ~ Insulation on piping and equipment is considered to be the primary source of post-accident debris inside containment which could potentially clog the sump screening...

Fine mesh filter screens are provided, completely enclosing the sump suctions. Enough wetted vertical screen area is provided such that, with an assumed 50 percent blockage, coolant velocity through the screens is approximately 0.2 ft/second. No credit is taken for the horizontal screen area. In addition, a fine, seismically supported vertical screen is provided in the sump to completely separate the redundant suction lines.

g) All screens and supporting structures are designed to withstand the effects of the SSE. The screens are 18 gage wire with an open area of .0081 square inches. The screen mesh size was selected to avoid entrapment of particles in the fuel assembly spacer grids and material is made of 304 stainless steel to resist corrosion and structural degradation.

NAC FOAM 366A <4.96)

NRC FORM 36SA U.S. NUCLEAR REGULATORY COMMISSIO (4-95) E LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 5 OF 8 97 002 00 TEXT /ifmore space is required, use eddilionel copies of NRC Form 3MAJ I17)

The actual field configuration of the Unit 2 containment sump debris screen included openings which were greater than that required by design specifications and therefore represented a condition outside the design basis of the plant.

Following this event, FPL performed a safety evaluation which reviewed the design requirements of the St. Lucie Unit 2 containment sump and concluded that the sump screen configuration provided in plant design documents was consistent with the guidelines of Regulatory Guide 1.82 and therefore acceptable.

An engineering review was performed which evaluated the safety significance and generic implications of the as-found condition of the St. Lucie Unit 2 containment sump screen enclosure. The review is summarized below.

The Unit 2 containment sump is protected against debris resulting from a postulated loss of coolant accident (LOCA) by two separate barriers. Course trash racks (with 3/4 inch openings) ensure that large debris is prevented from reaching the containment sump. A fine mesh screen with a design mesh size of .090 inches encloses the sump and a divider screen within the enclosure separates the two sump suction lines. The design fluid flow velocity across the screens is 0.2 feet/second and as built flow velocities are actually lower. Therefore, heavy solid particles would sink and not be entrained by the flow to the sump. Debris which would be entrained is on the order of 1.05 specific gravity (only slightly more dense than water) and of low structural strength.

n The Unit 2 fine mesh screens comprise several hundred square feet of filter screen area. The gaps which were identified during the sump walkdowns were on the order of several square inches and represented only a very small fraction of the total screen area. Moreover, the gaps were located on the divider screen and horizontal surface of the screen enclosure. The flow paths through these gaps do not represent direct paths to the sump suction lines and consequently, large, heavy particles would be expected to precipitate out before being entrained by the fluid flow into the suction piping.

The gaps in the outer containment fine mesh screen enclosure could have potentially allowed larger than design basis particles to enter the suction for the CS and HPSI systems. Openings in the divider screen could have allowed particles to enter the redundant spray header or the redundant HPSI train if one side of the screen enclosure was compromised. However, it should be noted that there are no identified credible mechanisms which would damage the screen enclosure during a LOCA.

The most limiting components, when considering particle size, are the CS and HPSI pumps, the HPSI throttle valves, the CS nozzles, and the fuel assembly spacer grids. The potential impact of the identified gaps in the screen enclosure and divider screen on these components is discussed in the following paragraphs.

NRC FOAM 366A I4.95I

I4-95I

'ICENSEE NRC FORM 366A EVENT REPORT TEXT CONTINUATION (LER)

U.S. NUCLEAR REGULATORY COMMISSIO YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 6 OF 8 97 002 00 TEXT (If more speceis required, use edditionel copies of NRC Farm 366A I I17)

The CS system is designed to reduce containment temperature and pressure following a postulated LOCA. The peak temperature and pressure occur early in the design basis LOCA scenario, and is essentially a function of the containment heat sinks. Significant cooling of the containment atmosphere by the CS system occurs during the injection phase of the LOCA event before suction is transferred to the containment sump from the refueling water tank [EIIS:BP]. Furthermore, the CS system is essentially redundant to the emergency containment coolers [EIIS:BK] for long term containment cooling and the containment coolers would not be affected by the condition of the containment sump enclosure. The CS pumps are capable of passing solid particles of 1/4 inch or less without damage and the CS nozzles are capable of passing solid particles of up to 3/8 inch. Both the pumps and spray nozzles would be expected to pass low density paiticles of much larger size without damage.

Therefore, the relatively small gaps in the sump screens would not be expected to adversely affect the CS system's ability to mitigate the consequences of a LOCA.

The initial ref looding of the reactor core is accomplished by the safety injection tanks and the low pressure safety injection (LPSI) system [EIIS:BP] during the injection phase of the event and are unaffected by the sump condition. The HPSI system provides simultaneous hot and cold leg injection during the recirculation phase of a I OCA. The HPSI pumps are capable of passing solid particles of 1/4 inch or less without damage. The HPSI throttle valves utilize a basket disk with four flow ports. The valves are capable of passing solid particles up to 0,19 inches but portions of the flow ports could be blocked by hard debris of 0.14 inches or more. The pumps and throttle valves would be expected to pass low density particles of much larger size without damage. Therefore, the relatively small gaps in the sump screens would not be expected to have adversely affected the HPSI system's ability to mitigate the consequences of a LOCA.

The St. Lucie Unit 2 UFSAR states that the design basis for the sump screen fine mesh size is to prevent debris from blocking the fuel assembly spacer grids. This consideration exceeds the requirements of Regulatory Guide 1.82, in that this is a much smaller particle size than could affect the most limiting HPSI or CS component. The fuel assembly flow channels. could be partially blocked by debris of approximately 0.124 inches or greater. However, considerable-area for flow is available around each fuel assembly and particles of approximately 0.255 inches would be required to block the widest part of the channel. Based on the relatively small area that the gaps in the screen represent, the amount of debris would be expected to be small and, as stated previously, the type of debris anticipated to be entrained would be of low density and low structural strength.

The sump design and design basis for the St. Lucie Unit 1 sump screens was reviewed for generic applicability to this event, and it was concluded that Unit 1 does not have the same potential for having sump screen gaps (beyond design) as found on Unit 2. The St. Lucie Unit 1 fine mesh screen consists of a small box surrounding each suction pipe and the enclosure does not involve a geometry as complex as the Unit 2 design. A double barrier to prevent large debris from entering the sump is also included on Unit 1. The rough screen utilizes steel grating and wire mesh with 1/2 inch clear openings with the exception of one section which utilizes 1/4 inch openings.

NRC FORM 366A I4-95I

I4-95)

'ICENSEE NRC FORM 36GA EVENT REPORT TEXT CONTINUATION (LER)

U.S. NUCLEAR REGULATORY COMMISSIO YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 7 OF 8 97 002 00 TEXT iifmoro spoco is roquirod, uso additional copies of NRC Form 366AI I17) ln addition, each Unit 1 recirculation line suction is encased with a fixed fine mesh screen capable of filtering out 1/4 inch particles. The Unit 1 screens are box type strainers, each with flow areas equivalent to two times the cross sectional area of the recirculation pipe. The pumps which use the containment sump for suction during the recirculation phase of a LOCA on Unit 1 have the capability of passing particles 1/4 inch and smaller without any detrimental effect on pump capability. Furthermore, the design basis of the fine mesh screen is 1/4 inch openings on Unit 1 as opposed to .090 inches on Unit 2, making the Unit 1 design basis more tolerant of small gaps equal to 1/4 inch or less.

Previous inspection of the Unit 1 containment sump concluded that the containment sump (grating and screening) was generally configured in accordance with UFSAR drawings. As previously discussed, a similar inspection performed for the Unit 2 containment sump had identified discrepancies in the field configuration.

All necessary field work to modify the St. Lucie Unit 2 containment sump in accordance with design requirements was completed prior to plant startup, and within the action requirements of the St. Lucie Unit 2 Technical Specifications. As discussed above, the affect of the identified gaps in the Unit 2 containment sump screen on the limiting ECCS, CS, and fuel components was assessed and it was concluded that the condition did not represent a significant impact to the operation of components required for accident mitigation. Therefore, the protection of the public health and safety was not adversely affected by this event.

FPL performed a safety evaluation to document the design and licensing basis requirements for the Unit 2 containment sump screens. Based on the evaluation, changes were submitted to update the Unit 2 UFSAR to more accurately describe the containment sump screen design.

2. The discrepancies associated with the St. Lucie Unit 2 containment sump screen enclosure were corrected in accordance with Plant Change/Modification (PCM) 97-037M. The PCM included modifications to the containment sump screens as-required to meet the intent of the applicable design drawings. This was completed prior to the Unit 2 startup following the Cycle SL 2-10 refueling outage.

3. To augment current surveillance instructions, additional procedural guidance will be developed for performing containment sump inspections to provide specific requirements for inspecting for gaps in the sump screen as well as verifying the cleanliness of the sump area.

The procedural guidance will be designed to ensure that the physical condition of the sump screens continues to meet the design requirements and that the filtering function of the screens remains intact.

NRC FOAM 366A I4.95)

I4-95)

'ICENSEE NRC FORM 36/A EVENT REPORT TEXT CONTINUATION (LER)

U.S. NUCLEAR REGULATORY COMMISSIO YEAR SEQUENTIAL REVISION ST. LUCIE UNIT 2 05000389 8 OF 8 97 002 00 TEXT ilfmore spaceis required, use additional copies of NRC Farm 366Ai I17)

4. The St. Lucie Unit 1 containment sump debris screens will be inspected during the next outage when Unit 1 enters Mode 5 for a sufficient duration. The inspection will include a detailed as-built verification of the screen configuration.

5. This event will be scheduled into the Engineering Support Personnel (ESP) training program at St. Lucie to provide emphasis on the continuing need for effective assessment and disposition of lessons learned from industry experience such as that contained in NRC Information Notice 89-77.

EailmkZnmpnnents Equipment: Containment Sump Debris Screen Enclosure Material: Type 304 stainless steel Cause code: B - Construction/Installation There have been no other similar events previously reported at St. Lucie NRC FORM 388A I4.95I

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