ML18016A797

LER 99-001-00:on 990106,SF Pool Water Level Was Not Maintained Greater than 23 Feet Above Stored BWR Fuel Assemblies.Caused by Fasteners Bending Under Specific Circumstances.Increased Water Level.With 990205 Ltr

ML18016A797
Person / Time
Site:	Harris
Issue date:	02/05/1999
From:	Brooke Clark, Ellington M CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HNP-99-015, HNP-99-15, LER-99-001, LER-99-1, NUDOCS 9902090363
Download: ML18016A797 (8)

Text

~ --CA~~GORY 10 REGULATORY INFORMATION DISTRIBUTION SYSTEM I

,(RIDS)'CCESSION NBR:9902090363 DOC.DATE: 99/02/05 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH.NAME AUTHOR AFFXLXATION ELL~NGTG8,M. Carolina Power &, Light Co.

CLARK,B.H. Carolina Power & Tight Co.

RECIP.NAME RECIPIENT AFFXLIATXON

SUBJECT:

LER 99-001-00:on 990106,SF pool water level was not maintained greater than 23 feet above stored BWR fuel assemblies. Caused by fasteners bending under specific A circumstances. Increased water:level-.With 990205 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

%is NOTES:Application for permit renewal filed. 0500040&

0 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL XD CODE/NAME LTTR ENCL PD2-1 PD 1 1 FLANDERS,S 1 1 INTERNAL: ACRS 1 1 2 2 AEOD/SPD/RRAB 1 1 1 1 NRR/DE/ECGB 1 1 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HXCB 1 1 NRR/DRCH/HOHB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 RES/DET/EIB ,1 1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 1 1 NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 C, NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DZSTRIBUTZON 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 REQUXRED: LTTR 23 ENCL 23

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'"'-: 'OL Carolina Power 8 Ught Company Harris Nudear Plant P.O. Box 165 New Hill NC 27562 FEB s1999 U.S. Nuclear Regulatory Commission Serial: HNP-99-015 ATTN: NRC Document Control Desk 10CFR50.73 Washington, DC 20555 HAMGS NUCLEAR POWER PLANT UNIT 1

.'HEARON DOCKET NO. 50400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 1999-001-00 t ~ J 4 ~ ~ r Sir or Madam:

In accordance with 10CFR50.73, the enclosed Licensee Event Report is submitted. The report describes a Technical Specification violation pertaining to spent fuel pool water level.

Sincerely, B.H. Clar General Manager Harris Plant Enclosure c: Mr. J. B. Brady (HNP Senior NRC Resident)

Mr. L. A. Reyes (NRC Regional Administrator, Region II)

Mr. S. C. Flanders (NRC NRR Project Manager) cycy0g0q0363 9'90205 PDR ADQCK 05000400 S PDR 541 3 Shearon Harris Road New Hill NC

U. S. Nuclear Regulatory Co ion

~) Document Control Desk / HNP-99-015 Page 2 of 2 bcc: Ms. D. B. Alexander Mr. G. E. Attarian Mr. R. H. Bazemore Mr. T. C. Bell Mrs. P. P. Burns Mr. H. K. Chernoff (RNP)

Mr. B. H. Clark Mr. W. F. Conway Mr. J.-M. Curley Mr. G. W. Davis Mr. W. J. Dorman (BNP)

Mr. R. J. Field Ms. J. P. Gawron (BNP)

Mr. K. N. Harris Ms. L. N. Hartz Mr. J. D. Henderson Mr. W. J. Hindman Mr. C. S. Hinnant INPO Mr-. W. D. Johnson Mr. M. B. Keef Mr. G. J. Kline Ms. W. C. Langston Mr. R. D. Martin Mr. J. W. McKay Mr. R. O. Moore Mr. T. C. Morton Mr. P. M. Odom (RNP)

Mr. P. M. Sawyer (BNP)

Mr. J. Scarola Mr. F. E. Strehle Mr. J. M. Taylor Harris Licensing File(s)

Nuclear Records

APPROV OMB NO. 3150-0104 EXPIRES 06/30/2001 NRC FORM 366 U.S. NUCLEAR REGULA COMMISSION Estimated n per response to comply with this mandatory information (6-1998) collection request: 50 hrs. Reported lessons learned are incorporated into the licensing process and fed back to industry. Forward comments regarding burden estimate to the Information and Records Management Branch (Te LICENSEE EVENT REPORT (LER) F33), U.S. Nudear Regulatory Commission, Washington, Dc 205554001, and to the Paperwork Reduction Pro}ect (31504104), Office of Management and Budget, Washington, DC 20503. If an information collection does not (See reverse for required number of display a currently valid OMB control number, the NRC may not conduct or digits/characters for each block) sponsor, and a person is not required to respond to, the information collecten.

DOCKET NUMBER I2) PAGE I3)

FACILITYNAME l1 I 1 OF 3 Harris Nuclear Plant, Unit 1 05000400 TITLE (4l Spent Fuel Pool water level not maintained greater than 23 feet above stored BWR fuel assemblies.

REVISION MONTH DAY YEAR FACIUTY NAME DOCKET NUMBER MONTH DAY YEAR SEQUENTIAL NUMBER NUMBER 06'EAR PACIUTY NAME DOCKET NUMBER 01 "1999 1999. - 001' 00 02 05 1999 05000 OPERATING MODE (9) 20.2201(b) 20.2203(a)(2)(v) x 50.73(a)(2)(i) 50.73(a)(2)(viii)

POWER 100 20.2203(a)(1l 20.2203(a)(3)(I) 50.73(a)(2)(ii) 50.73(a) (2)(xl LEVEL (10) 20.2203(a)(2) (i) 20.2203(a)(3) (ii) 50.73(a)(2)(iii) 73.71 20.2203(a) (4) 50.73(a)(2)(iv) OTHER 20.2203(a)(2)(ii) 50.36(c) (1) 50.73(a) (2)(v) Specify ln Abstract below 20.2203(a)(2)(iii) 50.73(a)(2)(vii) or in NRC Form 366A 20.2203(a) (2)(iv) 50.36(c)(2)

NAME TELEPHONE NUMBER Ilnclude Ares Code)

Mark Ellington, Senior Analyst - Licensing (919) 362-2057 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13)

SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE To EPIX To EPIX EXPECTED MONTH DAY YEAR YES NO (If yes, complete EXPECTED SUBMISSION DATE).

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

At approximately 10:30 on January 6, 1999, with the unit at 100% power, personnel performing spent fuel handling operations noticed that one of the Boiling Water Reactor (BWR) assemblies that they were moving did not fully seat in the storage rack. A question was raised regarding the administrative limit required to maintain 23 feet of water above the fuel assemblies as required by Technical Specification LCO 3.9.11. It was determined that the current limit did not consider the additional margin needed in the event of an assembly being hung on a BWR channel fastener; therefore, fuel movement was halted. An investigation revealed that eight additional assemblies in the pool were not fully seated. Measurements were taken on the nine assemblies to determine what the most limiting administrative requirement should have been. Based on these measurements, 23 feet of water had been maintained above the most limiting assembly since the problem was discovered on January 6, 1999; however, a subsequent review of the operating logs for the previous months showed that the revised administrative limit (1.25" higher than the previous limit) had not been met (by a maximum of 0.75") on more that one occasion. Therefore, the actions required by LCO 3.9.11 were not met on those occasions.

The root cause of this event is that the procedure provides ambiguous guidance regarding channel fastener tolerances and the fact that the fasteners could bend under specific circumstances. Corrective actions taken have been: 1) Halted fuel movement and increased water level to ensure compliance; 2) Seated seven of the nine assemblies (i.e., these seven did not have bent channel fasteners, but were hung on the side of the fuel rack by the lower edge of the fastener); 3) Revised the administrative limit such that 23 feet of water remained above the two BWR assemblies with bent channel fasteners (i.e., not fully seated); 4)

Performed an engineering analysis for a BWR assembly being suspended on a side of a rack by a channel fastener, and 5)

Seated the two assemblies with bent channel fasteners. Planned corrective actions are to revise procedures and to provide additional trainin for fuel handlin ersonnel.

NRC FORM 366 I6.1998I

ly NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION 4

(6-98)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FAGIUTY NAME (1) DOCKET LER NUMBER (6) PAGE (3)

SEQUENTIAL REVISION Harris Nuclear Plant, Unit 1 05000400 YEAR NUMBER NUMBER 2 OF 3 1999 001 00 TEXT litmore spsce is reqofred, use eddidonsl copies of NRC Form 368AJ (17)

I. DESCRIPTION OF EVENT In August of 1997, during an in-depth review of how the plant complies with technical specification surveillance requirements, the Harris Nuclear Plant made a conservative decision to include the handling bail on the Boiling Water Reactor (BWR) (EIIS: AC) assemblies as part of 'the assembly.'he top of this bail is approximately six inches over the top of the remainder of the fuel assembly (see LER 97-021-00, with an event date of 8/14/97).

Since that determination, a revision to clarify the wording of the specification has been submitted to the NRC.

That revision was still pending as of the date of this event.

At approximately 10:30 on January 6, 1999, with the unit at 100% power, personnel performing fuel handling operations in the Fuel Handling Building (FHB) noticed that one of the BWR assemblies they were moving did not appear to be fully seated. The fuel handling personnel notified the Spent Fuel Shipping Director that they were, having difficulty getting a BWR assembly to fully seat in its location, apparently due to a bent channel fastener.

A channel fastener is an attachment on one of the upper corners'of a BWR assembly, which holds the channel to the assembly and provides proper spacing for the cruciform control blades. Fuel handling procedures provided guidance for instances such as when an assembly was not fully seated, and that guidance was followed. In addition to those actions, one of the technicians assisting in the evolution questioned how this situation would affect the administrative limits established to maintain a minimum of 23 feet of water above the fuel assemblies, as required by Technical Specification Limiting Condition for Operation (LCO) 3.9.11 Through conversations

~

with the Shipping Director and Engineering, it was determined that the current administrative limit did not" consider the additional margin needed in the event of an assembly being hung on the side of the rack by a channel fastener. The limit had been based on the most limiting design parameters, but did not assume that the assemblies were not fully seated in the racks. Fuel movement was immediately halted and water level was increased to ensure compliance with the technical specification LCO. An investigation found eight additional assemblies in the pool that were not fully seated. The position of these assemblies was not readily apparent with the naked eye, but underwater video images of the assemblies in the racks made the nine more readily distinguishable from those fully seated. Two of the nine had bent channel fasteners. The remaining seven did not have bent channel fasteners, but were being supported on the top edge of the rack wall by the lower edge of the channel fasteners. Measurements were taken on the nine assemblies to determine what pool level was needed to ensure compliance with technical specifications. It was determined that the administrative limit needed to be increased by 1.25" for the most limiting assembly to be in compliance. Based on these measurements, 23 feet of water had been maintained above the most limiting assembly since the problem was discovered on January 6, 1999; however, a review of the operating logs from August 14,1997, to the event date showed that the revised administrative limit had not been met on more than one occasion. The lowest water level recorded since August 14, 1997, was 22 feet and 11.25 inches above the bail of the most limiting BWR assembly (i.e., 0.75" less than the new administrative limit). Therefore, the actions required by technical specification LCO 3.9.11 were considered to have not been met on those occasions.

NRC FORM 366 (6-96)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION IB-96)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET LER NUMBER I6) PAGE I3)

FACILITYNAME I1I SEQUENTIAL REVISION Harris Nuclear Plant, Unit 1 05000400 YEAR NUMBER NUMBER 3 OF 3 1999 001 00 TEXT llfmore space ls rerlulred, use addidonal copies of NRC Form 388AJ I17)

II. CAUSE OF EVENT The root cause of this event is that the procedure provides ambiguous guidance regarding channel fastener tolerances and the fact that the fasteners could bend under specific circumstances.

III. SAFETY SIGNIFICANCE There were no actual safety consequences. Records indicate that the water level in the spent fuel pool did not decrease below 23 feet above the top of the fuel rods. Technical Specification bases states that "[t]he restrictions on minimum water level ensure that sufficient water depth is available to remove 99% of the assumed 10'k iodine gap activity released from the rupture of an irradiated fuel assembly. The minimum water depth is consistent with the assumptions of the safety analysis." Since at least 23 feet of water was maintained above the actual fuel rods, there was no degradation in the protection of the health or safety of the public, nor was there any threat of a radiological release as a result of this event.

This LER is being submitted pursuant to the requirements of 10 CFR 50.73 (a)(2)( i ) for a condition prohibited by Technical Specifications.

IV. CORRECTIVE ACTIONS Completed corrective actions:

1. Halted fuel movement and increased water level to ensure compliance.

2. Seated seven of the nine assemblies (i.e., these seven did not have bent channel fasteners, but were hung on the side of the fuel rack by the lower edge of the fastener) on 1/8/99.

3. Revised the administrative limit such that 23 feet of water remained above the two BWR assemblies with bent channel fasteners (i.e., not fully seated).

4. Performed an engineering analysis for a BWR assembly being suspended on a side of a rack by a channel fastener.

5. Seated the two assemblies with bent channel fasteners on 2/2/99.

Planned corrective actions:

1. Revise procedures and provide additional training for fuel handling personnel by 4/15/99.

V. SIMILAR EVENTS There has been one previous condition identified related to required water level over BWR fuel. LER 97-021-00

, discussed an interpretation issue regarding what constitutes a fuel 'assembly.'orrective actions for that event are not directly applicable to the channel fastener issue.

NRC FORM 366A I6.99)