ML17334B758

LER 98-008-01:on 980112,damaged Ice Condenser Ice Basket Removed from Unit 1 Ice Condenser.Caused by Inadequate Control of Contractors & Inappropriate Maint.Damage Beyond Threshold Will Be Repaired & replaced.W/980504 Ltr

ML17334B758
Person / Time
Site:	Cook
Issue date:	05/04/1998
From:	Pisarsky F, Sampson J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-008, LER-98-8, NUDOCS 9805080084
Download: ML17334B758 (11)

Text

0 CATEGORY 1 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) ~

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1QQ ACCESSION NBR-9805080084 DOC.DATE: 98/05/04 NOTARIZED: NO DOCKET ~0.

FACIL:50-,316 Donald C. Cook Nuclear Power Plant, Unit 2, Indiana M 0500031)/,,

AUTH.NAME AUTHOR AFFILIATION PXSARSKY,F. Xndiana Michigan Power Co. (formerly Indiana & Michigan Ele SAMPSON,J.R. Xndiana Michigan Power Co. (formerly Indiana 8 Michigan Ele RECXP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 98-008-01:on 980112,demaged ice condenser ice basket removed from Unit 1 ice condenser. Caused by inadequate control of contractors & inappropriate maint.Damage beyond threshold will be repaired E replaced.W/980504 ltr.

DXSTRXBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:

RECIPIENT COPXES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-3 PD 1 1 STANG, J 1 1 R INTERNAL! D/RAB 2 2 AEOD/S PD/RRAB 1 1 Y FILE 1 1 NRR/DE/ECGB 1 1 EELB NRR/DRCH/HHFB NRR/DRCH/HOLB ~

1 1

1 1

1 1

NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB 1,1 1

1 1

1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRZB 1 1 RES/DET/EXB 1 1 RGN3 FILE 01 1 1 D EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 1 1 0 NOAC POORE,W. 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. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 24 ENCL 24

r Indiana Michigan Power Company Cook Nuctear Rant 0

One Cook Piece Bridgman, MI49I06 INDIANA NICHIOiAN POWER May 4, 1998 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Operating Licenses DPR-58 Docket No. 50-315 Document Control Manager:

~hfll In accordance with the criteria established by 10 CFR 50.73 entitled 98-008-01 ig p  !'big 1 i d:

Sincerely, J. R. Sampson Site Vice President Imbd Attachment A. B. Beach, Region III J. R. Sampson P. A. Barrett S. J. Brewer R. Whale D. Hahn Records Center, INPO NRC Resident Inspector

'it805080084 'at80504 PDR ADQCK 050003ih 8 POR

NRC FORH 366 .ST NUCLEAR REGULATORY COMHISSION OVED SY OMS HO. 3150.0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEH PER RESPONSE TO COHPLY WITH THI INFORMATION COLLECTION REQUEST: 50.0 ttRS. FORFAR LXCENSEE EVENT REPORT (LER) COHMENTS REGARDING BURDEN ESTIHATE TO TH INFORMATION AND RECORDS MANAGEMEHT BRANCH (MNS 7714), U.ST NUCLEAR REGUI.ATORY COHMISSION, 4ASHIHGTON, DC 20555-0001, AND TO THE PAPERNOR REDUCTION PROJECT (3150-0104), OFFICE 0 MANAGEMENT AND BUDGET NASHINGTON DC 20503.

FACILITY NAHE (1) DOCKET NUMBER (2) Page 1 of6 Donald C. Cook Nuclear Plant - Unit 1 50.315 TITLE (4)

Inadequate Contractor Control during Maintenance and Surveillance Activities Results in Ice Basket Damage EVENT DATE 5 LER NUMBER 6 REPORT DATE 7 OTHER FACILITIES INVOLVED 8 SEQUENTIAL REVISION FACILITY NAME DOCKET NUHBER HONTH DAY YEAR YEAR NUMBER NUMBER HONTH OAY Cook - Unit 2 50-316 FACILITY HAHE DOCKET NUMBER 02 12 98 98 008 01 05 04 OPERATING TN S REPORT IS SUBMITTED TO THE REQUIREMENTS OF 10 CFR  : Check one or more 11 MDOE (9)

PURSUANI'0.2201(b) 20.2203(a)(3)(1) 50.73(a)(2)(iii) 73.71(b)

PINER 00 20.2203 a 1 20.2203 a 3 ii 50.73 a 2 iv 73.71o LEVEL (10) 20.2203(a)(2)(I) 20 '203(a)(4) 50 '3(a)(2)(v) OTHER 20.2203 a 2 ii 50.36 c 1 50.73 a 2 vfi (Specify in 20.2203(a)(2)(iii) 50 '6(c)(2) 50 '3(a)(2)(viii)(A) Abstract betoN and in Text, 20.2Z03(a)(2)(iv) 50.73(a)(2)(1) 50.73(a)(2)(viii)(B) NRC Form 366A) 20.2203(a)(2)(v) X 50.73(a)(2)(ii) 50 '3(a)(2)(x)

LICEHSEE CONTACT FOR THIS LER 12 NAHE TELEPHONE NUMBER (Include Area Code)

IVIr. Frank Pisarsky, Mechanical Component Engineering Supervisor 616/465-5901, x2607 COMPLETE ONE LINE FOR EACH COMPONENT FA LURE DESCRIBED IN T HIS REPORT REPORTABLE REPORTABLE CAUSE SYSTEH COHPONENT MANUFACTURER CAUSE SYSTEH COMPONENT HANUFACTURER TO HPRDS TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED MONTH DAY YEAR YES BUSH I SS I OH X (lf yes, complete EXPECTED SUBHISSION DATE). DATE (15) 08 03 98 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typeMritten lines) (16)

On January 12, 1998, with Unit 1 in Mode 5, a.damaged ice condenser ice basket was removed from the Unit 1 ice condenser and a scoping test was performed to determine its ability to structurally withstand design basis loads. The scoping test results showed that the damaged ice basket failed with plastic deformation under less than design basis loads. This event was reported via ENS on January 12, 1998 at 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br /> EST under 10CFR50.72(b)(2)(i), as an unanalyzed condition and a condition outside the plant's design basis. Prior to and subsequent to this notification, several forms of ice basket damage were identified including damaged upper rims, missing or tom ligaments, dents and folds. This LER is therefore submitted in accordance with 10CFR50.72(a)(2)(i).

The root cause of this condition has been attributed to inadequate control of contractors, and inappropriate maintenance and surveillance practices that resulted in damage to the ice baskets. A decision has been made to completely thaw both units ice condensers in order to address a variety of issues identified during the current unit outages. Ice baskets will be inspected to identify damage, and damaged baskets will be repaired or replaced.

Methods for oversight of the ice condenser labor force are being reviewed, along with ice crew training, maintenance and surveillance practices to ensure they support behaviors and techniques to preclude further basket damage.

These reviews will be completed and appropriate improvements will be implemented during the current outages.

. Based on available information, analysis of the various types of basket damage concluded that the baskets would have functioned to prevent containment overpressure. Further analysis will be performed, as necessary, once all ice baskets have been inspected following ice condenser thaw

NRC FORH 366A U. . UCLEAR REGULATORY COHHISSION ROVED BY OHB NO. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY lllTH THI IHFORMATION COLLECTIOH REQUEST: 50.0 HRS. FORNAR LICENSEE EVENT CONTINUATION COMMENTS REGARDING BURDEN ESTIMATE TO '-TH INFORMATION AND RECORDS MANAGEHENT BRANCH (MNB 7714), U.S. NUCLEAR REGULATORY COMMISSION)

NASNINGTON, DC 20555-0001, AND TO THE PAPERNOR REDUCTION PROJECT e (3150 0104), OFFICE 0 MANAGEMENT AND BUDGET MASHINGTON DC 20503 NAME 1 DOCKET NUMBER 2 LER NUMBER 6 PAGE 3'ACILITY YEAR SEQUENTIAL REVISION Cook Nuclear Plant - Unit 1 50-315 98 008 01 2OF6 TEXT (if more space is required. use additional NRC Foaa 366A's) (17)

C d I ur e Unit 1 was in Mode 5, Cold Shutdown Unit 2 was in Mode 5, Cold Shutdown On January 12, 1998, with Unit 1 in Mode 5, a damaged ice condenser ice basket was removed from the Unit 1 ice condenser and a scoplng test was performed to determine its ability to structurally withstand design basis loads.

The scoping test results showed that the damaged ice basket failed with plastic deformation under less than design basis loads. This event was reported to the NRC on January 12, 1998 as an unanalyzed condition. Prior to and subsequent to this notification, several forms of ice basket damage were Identified including damaged upper rims, missing or tom ligaments, dents and folds.

Each ice condenser consists of 24 bays containing 81 ice baskets per bay, covering an arc of 300 degrees in the containment structure. Each ice basket is approximately 12 inches across and 48 feet long, filled with borated ice.

To perform their design basis function, the ice baskets and columns are required to withstand design loads to ensure they do not eject upward out of the ice bed and open up bypass flow routes, or impact and damage other ice condenser equipment, or eject out of the ice condenser and become a missile inside containment. The baskets are designed to not collapse causing adjacent'or'additional ice basket columns to collapse, resulting in excessive flow passageway blockage, bypass flow routes, or undefinable heat transfer geometry.

During the current outages, damage was Identified to ice condenser ice baskets during tours of the ice condenser.

Damage noted on ice baskets includes damaged top rims, tom/missing ligaments, dents and folds. Folds are considered to be the most significant damage, resulting in the basket material has undergone plastic deformation in compression. Based on preliminary inspections performed in each unit's ice condenser with the ice bed intact, approximately 25 baskets in Unit 1 and 45 baskets in Unit 2 exhibit folds. A similar number of baskets exhibit dents.

Top rim damage is common, however, it is not structurally significant, except that it may impede the ability to weigh a basket. The exact number of damaged baskets, considering the various types of damage, will be determined as a result of planned inspections during the current outages.

The observed damage can be attributed to improper handling of baskets during maintenance and surveillance activities. Because damage occurred during basket maintenance and surveillance activities, and contract personnel perform the majority of this work, inadequate control of contractors is considered a primary cause for the noted condition. Contributors to this cause include ineffective training for contract personnel and inadequate supervisory oversight by utility personnel.

Improper surveillance practices was another contributor, since some of the more significant basket damage occurred during attempts to move baskets from beneath during weighing.

Damaged top rims and folds in the baskets most likely occurred during the baskets weighing process. The process of weighing baskets requires lifting the basket from the top rim with a weigh rig. Over time, some baskets have become frozen in place. In order to free frozen baskets for weighing, various techniques have been used. One technique used in the past was "jacking" of baskets from the bottom as the basket was pulled from above. Failure to control the jacking in the event the basket remained frozen sometimes resulted in deformation of the basket and produced a fold in the ligaments near the basket bottom. The practice of jacking baskets from the bottom was discontinued several years ago to preclude further basket damage.

NRC FORM 366A U.S. CLEAR REGULATORY COMHISSION OVED BY OHB NO. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COHPLY WITH THI LICENSEE EVENT CONTINUATION IHFORHATION COLLECTION REQUEST: 50.0 HRS. FORWAR COMHENTS REGARDING BURDEN ESTIMATE TO TH IHFORHATION AND RECORDS MANAGEHENT BRANCH (HNB U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO 1'HE PAPERWOR REDUCTION PROJECT (3150-0104), OFFICE 0 HANAGEMEHT AHD BUDGET 'WASHINGTON DC 20503.

FACILITY NAME 1 DOCKET NUMBER 2 LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION Cook Nuclear Plant - Unit 1 50-315 98 008 01 3 OF 6 TEXT (if sere space is required. use additional NRC Fons 366A's) (17)

C us n 'd Other types of damage can also occur to baskets during the weighing process if not carefully controlled. As previously noted, the weighing process requires lifting the basket by pulling from the top rim. Although limits are set on maximum liftforces, top rim damage can quickly occur if liftforces are not closely monitored, or if loading is applied asymmetrically. Damage can also occur during the weighing process when a frozen basket is exercised in an attempt to free it.

Still other observed damage is considered to be the result of ice basket mishandling or inappropriate maintenance activities. Two examples of this type damage include inward dents in areas of basket ligaments and tom ligaments.

Dents probably occurred during basket installation, or perhaps during clearing of flow passages. Tears in ligaments are most likely the result of prolonged contact with a pneumatic vibrator, which is used for emptying of ice baskets.

The vast majority of ice condenser work has been performed in the past by a contract labor force, with the contract being administered by the Engineering department and specifically, the System Engineer. The contract administration responsibility was in addition'o the System Engineer's normal role of management of the technical scope of the ice condenser work and analysis of surveillance test results. This broad scope of responsibilities allowed only minimal time for field oversight of the contractor. Steps were not taken to make other utility personnel available for oversight of the contract labor force. Therefore, field supervision for contract workers was largely provided by contract supervisory personnel rather than by utility personnel. During the current outages, steps were taken to transfer responsibility for oversight of the ice condenser labor force to the maintenance department, which retains personnel skilled in the supervision of production labor. These steps are aimed at addressing issues with poor control of contractors.

The System Engineer historically administers a training program to the ice condenser contract personnel. This training includes guidance on basket weighing techniques and on appropriate use of tools to avoid damage to baskets. However, this training has apparently not been effective in preventing basket damage. Steps are being taken to overhaul this training, in part to reinforce appropriate techniques to preclude various types of ice basket damage.

Finally, the lack of a definition. of what constitutes "detrimental damage" was also viewed as a contributor, since there was no benchmark for personnel to gage whether observed damage resulted in an unacceptable condition.

Simplistically, any basket damage sufficient to challenge the basket's ability to carry design loads is considered detrimental damage Documentation of damage to Cook Plant ice baskets in previous corrective action documents provides evidence that the organization was able to recognize damaged ice baskets as a condition adverse to quality. In fact, the Technical Specifications (T/S) require periodic inspection of a sample of ice baskets for detrimental damage.

However, a definition of detrimental damage does not exist, other than wording in T/S 4.6.5.1.d, which refer to detrimental damage as "structural wear, cracks, corrosion or other damage." This lack of an objective definition may have contributed to confusion about the significance of the damaged ice baskets.

NRC FORH 366A U.S. CLEAR REGULATORY COHMISSION OVED BY OMB NO. 3150 0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY NITM THI IHFORMATION COLLECTIOH REQUEST: 50.0 MRS. FORMAR LICENSEE EVENT CONTINUATION COMMENTS REGARDING BURDEN ESTIMATE TO TH INFORHATION AND RECORDS MANAGEHENT BRANCH (MNB 7714)g U ST NUCLEAR REGULATORY COMMISSIONS NASHINGTON, DC 20555-0001, AND TO THE PAPERIIOR REDUCTION PROJECT (3150-0104), OFFICE 0 MANAGEMENT AND BUDGET liASHINGTON DC 20503.

FACILITY NAME 1 DOCKET NUHBER 2 LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION Cook Nuclear Plant - Unit 1 50-315 98 008 01 4OF6 TEXT (If cere space is required. use additional HRC Fore 3664's) (17) na s he Eve On January 121998, at 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br /> EST an ENS notification was made regarding damaged ice baskets in accordance with 10CFR50.72(b)(2)(i), as an unanalyzed condition and a condition outside the plant's design basis, following receipt of a scoping load test result on a damaged ice basket with buckling damage near the basket bottom rim. Baskets with buckling damage are considered to bound other types of ice basket damage identified during the current outages due to these baskets having undergone plastic deformation. This LER is submitted in accordance with 10CFR50.73(a)(2)(i).

This test examined the damaged basket's ability to structurally withstand static test loads equivalent to the Operational Basis Earthquake (OBE) and ice basket dead weight loads. The scoping test results showed that the damaged ice basket failed with plastic deformation under a distributed lateral load of approximately 400 Ibs in I'

, specifies that the ice basket should be able to withstand a lateral load equivalent to approximately 2400 Ibs distributed over the bottom 6 feet of the basket in conjunction with a compressive vertical load of 4933 lbs. The failure of this basket under less than design loads was considered to be an unanalyzed condition and thus was reported to the NRC per 10CFR50.72. Approximately 25 baskets in Unit 1 and 45 baskets in Unit 2 are currently know to exhibit similar damage.

The damaged ice baskets were evaluated as to compliance with the design basis, operability and functionality.

Several types of ice basket damage were considered, including top rim damage, tom/missing ligaments, dents and folds.

With regard to design basis, the baskets and columns of baskets are designed to withstand certain design loads to provide assurance of ice bed geometry for proper thermal/hydraulic performance of the ice condenser during a LOCA and/or seismic transient events. To perform their design basis function, the baskets and basket columns are designed to not eject upward out of the ice bed and possibly open up bypass flow routes, or impact and damage other ice condenser equipment, or eject out of the ice condenser becoming a missile inside containment. Baskets must also not collapse causing adjacent baskets/columns to collapse, resulting in flow passageway blockage, bypass flow routes, or unanalyzed heat transfer geometries.

Top rim damage has been reviewed and determined to not be a condition that would challenge the design basis or make the ice condenser inoperable. Damage at the top end of the basket column will not promote the ejection of an ice basket or column from the ice bed or promote detrimental damage at any adjacent ice basket columns, interfacing structures or equipment. From'the aspect of design, basis loads, top rim damage may result in some localized deformation, but it will not cause or promote collapse of that column, or damage adjacent baskets, basket columns, interfacing structures, or equipment. Baskets with damaged top rims will meet design basis load conditions and do not represent a challenge to operability or functionality of the ice condenser.

Missing or tom ice basket ligaments are not represented or taken into consideration on any design drawings or documentation. However, missing ligaments will not promote the ejection of an ice basket or basket column from the ice bed or promote detrimental damage at any adjacent ice baskets, basket columns, interfacing structures, or equipment. The ice basket includes substantial margin in its ability to resist tensile loads from potential LOCA blowdown forces. Ice baskets with missing ligaments wiil have reduced structural capacity to carry lateral and compressive loads imposed under design seismic load cases. The most common locations for missing ligaments are in the mid to upper elevations of the ice basket column due to ice bed maintenance operations with vibrators.

i/

HRC FORM 366A ~ ST NUCLEAR REGULATORY COMMISSION OVED BY OMB NO. 3150 0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTIOH REQUEST: 50.0 HRS.

LXCENSEE EVENT CONTXNUATXON FORIIARD COMMENTS REGARDING BURDEH ESTIHATE TO THE IHFORMATIOH AND RECORDS MANAGEHENT BRANCH.

(MHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION,

'WASHINGTON, DC 20555-0001, AHD TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503.

FACILITY NAHE 1 DOCKET NUMBER 2 LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION Cook Nuclear Plant - Unit 1 50-315 98 008 01 5 OF 6 TEXT (if cere space is required. use additional HRC Fons 366A's) (17) na At these higher elevations, the vertical compressive loads are not structurally significant and if the basket material were overstressed in combination with lateral loads, it is probable that the basket failure would be a smail localized lateral displacement or shift in the basket mesh ligaments around the area of the missing ligaments. This localized displacement of the ice basket section would not cause the damaged basket to impact on adjacent ice basket columns. Ice baskets with missing/damaged ligaments are considered to be outside the plant design basis, and equate to inoperability in the sense that the basket damage is detrimental, however, the damage does not result in the ice condenser being incapable of performing its design function to prevent containment overpressure following a high energy line break inside containment.

Dents and folds are considered to be the bounding (worst case) condition when evaluating safety significance. Ice baskets with dents and folds will have 'reduced structural capacity relative to their ability to carry lateral and compressive loads which would be imposed under design basis seismic load cases. The ice condenser design basis, as described in the FSAR, states that the ice condenser internal structures, including ice baskets, are designed to be capable of withstanding various load combinations including deadweight (D) plus operating basis earthquake (OBE) loads, D+ design basis earthquake (DBE) loads, D+ design basis accident (DBA) loads, and D+ DBE+ DBA loads.

As noted previously, a scoping test of a sample damaged basket with test loads less than D+ OBE resulted in a failure of the basket with plastic deformation. Therefore, the existence of damaged baskets which were unable to withstand design loads represented a condition outside the design basis. As noted previously, it is estimated that approximately 25 baskets in the Unit 1 ice condenser and 45 baskets in the Unit 2 ice condenser exhibit similar damage. Baskets with dents are estimated to be a similar quantity of baskets, with a final quantification to be made following inspections during the current outages.

With regard to operability, both unit's T/S require periodic inspections of ice baskets for "detrimental damage", to demonstrate operability.'hile the term "detrimental damage" has not been formally defined, damage, which results in a basket's inability to carry design loads, is considered detrimental. Therefore, the existence of these damaged ice baskets is considered to represent an inoperable condition for each ice condenser.

With regard to functionality, ice baskets with folds will have reduced structural capability relative to their ability to carry lateral and compressive loads, which would be imposed under design basis seismic load cases. The potential for continued ice basket failure under design basis seismic loading conditions at the fold is a function of the size of the damage, and the weight of the ice in the basket sections above the damage area. It may be postulated that the displacement of the damaged basket section under a seismic loading may be enough to cause the basket to displace laterally into an adjacent ice basket column. However, since basket sections with folds have been shown to have substantial strength as demonstrated in aforementioned testing (which bounds dents, where plastic deformation has not occurred), and since significant energy would be dissipated in the deformation of the ice basket sheet metal section and enclosed ice, it is expected that ice basket structural integrity will be maintained, so as to preclude significant collateral ice basket damage and flow passage geometry degradation. Because of this and the fact that each ice basket column is supported laterally every six feet in elevation by a structural lattice frame grid, it is highly improbable that a significant domino type failure would occur where the damaged basket collapses into an adjacent basket and so forth. Therefore, ice baskets with dents and folds are considered to be out of the design basis, and inoperable from the standpoint of compliance with the surveillance requirement related to detrimental damage, however, the damage does not result in the ice condenser being incapable of performing its design function to prevent containment overpressure following a high energy line break inside containment.

HRC FORM 366A .S. NUCLEAR REGULATORY COMMISSION OVED BY OMB iiO. 315D D104 EXPIRES 5/31/95 STIMATED BURDEN PER RESPOHSE TO COMPLY llITH THIS INFORMATION COLLECTION REQUEST: 50.0 NRS.

LICENSEE EVENT CONTINUATION FORliARD COMMEHTS REGARDING BURDEH ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (HNBB 7714), U.S. NUCLEAR REGULATORY COHHISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERNORK REDUCTION PROJECT (3150 0104), OFFICE OF HANAG'EMERY AND BUDGET NASNIHGTON DC 20503.

FACILITY NAME 1 DOCKET NUMBER 2 LER NUMBER & PAGE 3 YEAR SEQUEHTIAL REVISION Cook Nuclear Plant - Unit 1 50-315 98 008 01 6OF6 TEXT uf core space ls required. use additional NRC Fore 36&4's) Ill) a so e ve co Further evaluation of damage to the ice baskets and its potential impact on the ability of the ice condenser to perform its design function will be completed, as necessary, following the thaw of each unit's ice condenser.

Both unit's ice condensers are being completely thawed to allow inspection of the 1944 ice baskets in each unit, for the purpose of identifying and correcting, by repair or replacement, damaged baskets.

A definition of "detrimental damage" is being developed to serve as a gage for judging whether observed ice basket damage needs repair. This definition will be incorporated into design basis documents and procedures for surveillance of the ice condenser. Damage beyond the threshold of detrimental damage will be repaired or replaced.

These actions will be completed prior to startup for each unit.

After the thaw of each unit's ice condenser, a thorough inspection of ice baskets will be performed. Although these inspection activities will likely result in the identification of additional damaged baskets, the types of basket damage under consideration are not expected to change. This condition is applicable to both units.

Responsibility for oversight of production work - maintenance and surveillance activities - is being transferred from the Engineering to the Maintenance department. This will allow personnel skilled in supervising production workers to provide oversight for the ice condenser labor force, including contract labor, if used in the future.

The procedures used to guide maintenance and surveillance activities for the ice condenser are being upgraded and rewritten for use within the Maintenance department. The upgraded procedures will contain improved guidance on maintenance and surveillance activities to preclude future damage to ice baskets.

The training program for ice condenser workers is being upgraded. The upgraded training will include improved guidance on proper techniques to avoid basket damage.

Ice condenser maintenance procedures are being revised to require inspection of baskets emptied for maintenance prior to refilling during future outages. The basket inspection will specificaliy include provisions for identifying ice basket damage and correcting damage that exceeds the threshold of detrimental damage.

These preventive actions will be in place prior to commencing relevant ice condenser activities during the current outages on each unit.

Failed C m onen lde fica ion Not applicable e ou a Eve None