ML17329A256

LER 91-010-00:on 911016,sampled But Unmonitored Liquid Release Occurred When Liquid Radwaste Effluent Header Sample Gamma Radiation Detector Went Into Alarm.Caused by Poor Human Factors.Enhancements Made to procedure.W/911115 Ltr

ML17329A256
Person / Time
Site:	Cook
Issue date:	11/15/1991
From:	Blind A, Wojcik J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-91-010, LER-91-10, NUDOCS 9111210148
Download: ML17329A256 (6)

Text

ACCELERATED DI~UBUTION DEMONS~TION SYSTEM V

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9111210148 DOC.DATE: 91/11/15 NOTARIZED: NO DOCKET FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana M 05000315 AUTH. NAME AUTHOR AFFILIATION WOJCIK,J.T. Indiana- Michigan Power Co. (formerly Indiana & Michigan Ele BLIND,A.A. -

Indiana Michigan Power Co. (formerly Indiana & Michigan Ele RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 91-010-00:on 911016,sampled but unmonitored liquid release occurred when liquid radwaste effluent header sample D gamma radiation detector went into alarm. Caused by poor human factors. Enhancements made to procedure.W/911115 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

A NOTES RECIPIENT COPIES RECIPIENT COPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-1 LA 1 1 PD3-1 PD 1 1 D COLBURN,T. 1 1 INTERNAL: ACNW 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DS P 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DLPQ/LPE B 1 0 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR/DST/SELB SD 1 1 NRR/DST/SICBSH3 1 1 PLBSD1 1 1 NRR/DST/SRXB SE 1 1 G FILE 02 1 1 RES/DSIR/EIB 1 1 RGN3 FILE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 D

D D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOii! Pl-37 (EXT. 20079) TO Iil.l!i'IliPATE YOUR NM IE FROM DISTRIBUTION LISTS FOR DOCUKIENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL 31

Indiana Michigarl Power Company Cook Nuclear Piani One Cook Place Bridgman. MI 49106 616 465 5901 INfMANA NtCHIGAbf POWER November 15, 1991 United States Nuclear Regulatory Commi.ssion Document Control Desk Rockville, Maryland 20852 Operating Licenses DPR-58 Docket No. 50-315 Document Control Manager:

In accordance with the criteria established by 10 CFR 50.59 entitled Licensee Event Re ort S stem the following report is being submitted:

91-010-00 Sincerely,

~ A. Blind

~

Plant Manager AAB:sb Attachment co D. H. Williams, Jr.

A. B. Davis, Region E. E. Fitzpatrick III P. A. Barrett B. F. Henderson R. F. Kroeger B. Walters Ft. Wayne NRC Resident Inspector T. Colburn NRC J. G. Keppler M. R. Padgett G. Charnoff, Esp.

D. Hahn INPO S. J. Brewer/B. P. Lauzau B. A. Svensson

NRC FORM 366 V.S. NUCLEAR REGULATORY COMMISSION (639) APPROVED OMB NO. 31504104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUESTs 50.0 HRS. FORWARD LICENSEE EVENT REPORT {LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (PS30), V.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, OC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) PA E 3 Donald C. Cook Nuclear Plant Unit 1

'" Liquid Release to Unrestricted Area in Violation of Technical Specification 0 5 0 0 0 315 ioF04 Due to Poor Human Factors in the Desi n and 0 eration of the Release Monitor EVENT DATE (51 LER NUMSFR (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (6)

MONTH OAY YEAR YEAR c'j'j,'EQUENTIAL FrFS RSVlSION MQNTH DAY YEAR FACILITY NAMES DOCKET NUMBER(S)

NUMBER  %$ > NUMBER D. C. Cook Plant Unit 0 5 0 0 0 3 1 0 1 6 9 1 9 1 0 10 00 111 59 1 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT 7 0 THE RLQUIREMENTS OF 10 CFR (): ICnece one or more of rne followinpl (11 OPERATING MODE (9) 1 20.402(b) 20.405(c) 50.734)(2)(iv) 73.71(S)

POWER 20.405( ~ I (1)(I) 50.36(cl(1) 50.73(e)(2)(v) 73.7) lc)

LEYEL (10) 1 0 0 20.405 ( ~ ) ( I I(i(i 50.36(c)(2) 60,73( ~ ) (2((vii) DTHER (specify ln Aostrect below end ln Tert. NIIC Form 20.405 (c) (I ) (iti I X 50.73(e)(2HO 60,73(el(2)(xiii) (Al 366AI 20.405( ~ IIII(iv) 50.73( ~ l(2) (ii) 60,73( ~ l(2) (villi(BI 20.405(el(1 I (vl 50.7 3 (el l2) (iii) 50.73( ~ )(2)(xl LICENSEE CONTACT FOR THIS I.ER (12)

J. T. Vojcik Technical Physical Sciences " TELEPHONE NUMBER AREA CODE Department Superintendent 616 46 5-5 901 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT l13)

CAUSE SYSTEM COMPONENT MANVFAC. REPORTABLE MANUFAC < X~c 'come'PORTABLE TURER TO NPROS CAUSE SYSTEM COMPONENT TURER TO NPRDS X IL MO N E 0 7 0 IP%%&r SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES Ill yer, complete EXPECTED S(ISAIISSfOff DA TEI NO 0 5 1 5 9 2 ABSTRACT ILlmlt to 1400 spetes, ie., epproximetely frfmen sinpie specs typewritten lineD (16)

On October 16, 1991 approximately 1310 hours0.0152 days <br />0.364 hours <br />0.00217 weeks <br />4.98455e-4 months <br />, a sampled but unmonitored liquid release occurred when the liquid radwaste effluent header sample gamma radiation detector RRS-1000 went into an external fail status change alarm. At that time the alarm was acknowledged by depressing the acknowledge button. This action also bypasses the trip functions which allows opening of the waste release isolation valve to initiate sample flow to above the low flow trip setpoint of 3.1 gpm. To re-arm the trip function the sample flow must be increased to 5.5 gpm. During the 6 minutes of release prior to detecting the monitor's inoperable status, the re-arming flowrate had not been reached, and only 598 gallons of the 16,134 gallon tank had been zeleased.

The event was caused by poor human factors in the design and operation of the system which made it difficult for the operators to determine they had bypassed the trip function when the alazm aknowledge button was depressed.

Enhancements were made to the liquid waste release procedure to require increasing the sample flow rate to the level required for arming the trip setpoint. 1n addition, to aid the operators'n identifying the alarm condition the duration of the audible alarm will be increased. from seven to fifteen seconds. Further, noise suppression was installed to prevent radio fzequency field fz'om causing spurious alarms and design changes will be pursued to decrease the potential for personnel error.

NRC Form 366 (649)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION

~ APPROVED OMB NO. 31500')04 (64)9)

EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REQUEST: 50A) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P.530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PRO/ECT (31500104), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503 FACILITY NAME (1) DOCKET NUMBER u) LER NUMBER LB) PAGE (3)

VEAR SEQUENTIAL REVISION NUMBER NUMSER D. C. Cook Nuclear Plant Unit 1 p p p p p 3 1 5 9 1 1 0 00 02 OF 0 4 TEXT /// moro 4/>>co /1 PSII/)od, Irro odd/o'or>>/F/RC Form 366A'4/ (17)

Conditions Prior to Occurrence Unit 1 and Unit 2 in Mode 1 (Power Operation) at 100X power.

Descri tion of Event On October 16, 1991 at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> while preparing to release L91-136, a liquid radwaste release from Monitor Tank 3, RRS-1001, the radioactive liquid waste effluent header sample gamma radiation detector (EIIS/IL-MON) had an external fail status change alarm. At the same time the local area monitor associated with the liquid waste area monitor, RRS-1003, had a high fail status change alarm. At 1305 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.965525e-4 months <br />, the external fail status change alarm was cleared by pressing the alarm acknowledge button. The alarm acknowledgement also bypasses the trip functions to allow opening of the waste release isolation valve to initiate sample flow to clear the low flow trip setpoint of 3.1 gpm. However, to re-arm the trip function the sample flow must be increased to 5.5 gpm. During this release the re-arming flowrate was never reached.

When the external fail status change alarm cleared RRS-1001 exhibited a high fail status change alarm. The high fail status change alarm had probably been present since 1310 hours0.0152 days <br />0.364 hours <br />0.00217 weeks <br />4.98455e-4 months <br /> but was masked by the external failure. At 1309 hours0.0152 days <br />0.364 hours <br />0.00216 weeks <br />4.980745e-4 months <br /> RRS-1003 went into a low fail status. Also, at 1313 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />4.995965e-4 months <br /> a channel check was performed in accordance with the operations procedure to ensure operability during the release. The release was manually terminated at this time.

Cause of Event The event was caused by poor human factors in the design and operation of the system which made it difficult for the operators to determine they had bypassed the trip function when the alarm acknowledge button was depressed.

Factors contributing to this event include the following:

r

1. Audible alarms are short in duration and are not discernable from one channel to another or from one status to another with the exception of a high alarm.

Procedure guidance did not require the sample flow rate be increased to re-arm the trip function following an alarm acknowledge.

The radiation monitor microprocessor locks up due to generation of a radio frequency (RF) noise created by the trip relays during rapid status changes.

NRC Form 366A (64)9)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (64)9) APPROVED OI'IB NO. 31500)04 EXP IR ESI 4I30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LERI INFORMATION COLLECTION REQUEST: 500 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (PJ)30). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT (3)500104), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME 0 ) DOCKET NUMBER (2) LER NUMBER (6I PAGE (3)

.NR sEGUENTIAL REvlsroN YEAR BN2 D. C. Cook Nuclear Plant Unit 1 Qr(C< NIJMSE R NUM ER 0 5 0 0 0 3 1 5 9 1 01 0 00 03 oF 0 4 TEXT ffimore soeoeis ~ Jrrr)ed, Iree eddtdonel HRC Form 3664'4) l)2)

Anal sis of Event This event is considered reportable pursuant to 10 CFR 50.73(a)(2)(i)(B) as operation prohibited by the Technical Specification. Technical Specification 3/4.3.3 LCO 3.3.3.9 requires that with a required channel inoperable, releases may continue up to thirty days provided at least two independent samples are analyzed in accordance with Specification 4.11.1.1.1 and; at least two technically qualified members of the facility staff independently verify discharge valving prior to initiating the release otherwise, suspend releases via this pathway. Contrary to Technical Specification 3/4.3.3 Release L91-136 was not monitored for 6 minutes (598 gallons of the 16,134 gallons planned) via RRS-1001 nor was the dual sampling and independent discharge valving verification completed.

Reviews of the radiation monitoring system data, release flow rate, dilution water flow rate and the radioanalytical results indicated that at no time did the concentration of radioactive material discharged to Lake Michigan exceed the concentration limits listed in 10 CFR 20 Appendix B, Table 2. Therefore, this event did not have an impact on the health and safety of the public.

Corrective Action 4

Extensiv'e troubleshooting was performed on'RS-1000. It was found that if the signal to the sample flow switch was rapidly increased and decreased it created an RF noise which caused the microprocessor to lockup. The lockups cause RRS-1000 to become unresponsive. To correct this situation a modification was completed to install metal oxide varistors. The varistors prevent the RF field from developing.

In addition, enhancements were made to the operations liquid waste release procedure to require increasing the sample flow rate to the level required for arming the trip setpoint.

To raise the operator awareness of the radiation monitoring system status changes, the duration of the audible alarm will be increased *from seven to fifteen seconds. Design changes will also be pursued to remove the potential personnel error in the future.

Failed Com onent Identification Liquid Waste Discharge Monitor Plant Designation: RRS-1000 Manufacturer: Eberline Installed Design: American Electric Power Service Corporation (AEPSC)

NRC Form 366A (64)9)

NRC FORM 366A US. NUCLEAR REGULATORY COMMISSION (64)9) APPROVED OMB NO,31500104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REOUFSTI 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH IPB30), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, OC 20555. AND TO 1'HE PAPERWORK REDUCTION PROJECT (31504)104)> OFFICE OF MANAGEMENTAND BUDGET.WASHINGTON, DC 20503.

FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR SEQUENTIAL REVISION NUMSER NUMSER D. C. Cook Nuclear Plant Unit 1 o 5 o o o 3 9 1 0 1,0 0 0 0 4 OF 0 4 TEXT /lfmore 4aeoe ie rtyked, ore odd/done/ /iRC Form 36(/43/ ((7)

Previous Similar Events LER 50-315/91-003 NRC Form 366A (669)