ML20043C036

LER 90-003-01:on 900423,discovered That Incorrect Monitoring Instrumentation for Radiological Effluent Ventilation Sys Utilized to Comply W/Tech Specs.Caused by Mgt Oversight.Logs Process Monitors Will Not Be used.W/900523 Ltr

ML20043C036
Person / Time
Site:	Arkansas Nuclear
Issue date:	05/23/1990
From:	Ewing E, Millar D ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1CAN059006, 1CAN59006, LER-90-003-01, LER-90-3-1, NUDOCS 9006010229
Download: ML20043C036 (4)

Text

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Am Power a upht company W Nel'oYiYo*

noswww. An 728ci Tel 501964 3100 May 23, 1990 1CAN059006 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station P1-137 Washington, D. C. 20555

SUBJECT:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 o License No. OPR-51 Licensee Event Report No. 50-313/90-003-00 Gentlemen:

In accordance with 10CFR50.73(a)(2)(1)(B). attached is the subject report concerning a lack of understanding > of operability which resulted in the incorrect monitoring instrumentation for Radiological Effluent Ventilation Systems being utilized to comply with Technical Specifications.

Very truly yours,

)

/ E. C. Ewing General Manager, Technical Support and Assessment ECE/0M/sgw Attachment cc: Regional Administrator Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 INPO Records Center Suite 1500 1100 circle 75 Parkway Atlanta, GA 30339-3064 S

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- t form 1069.01A NRC fore 366 U.S. Nuclear Regulatory Commission (6 89) Approved OMB No. 3160 0104 Expirest 4/30/92 LICEN5EE EVENT REPORT (L E R) .

IACILi W hAME (1) Arkansas huclear One, Unit One lDOLLET NdME,ER (2) lF AGE (3) I 10l$1010101 31 11 311lOrl0l3 IlTLE (4) Due to a Lack '_of Unoerstanding of Operability the incorrect Monitoring Instrumentation for Radiological Effluent Ventilation Systems Were Utilized to Comply with Technical

$pecifications M T DATE (5) ,ER NUMBER (6) REPORT DATE (7) OTHER F ACIL] TIES ]NVOLVED (B) l i , iequential,l , Revision. l l t Mont h

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Day (Year l Year Number Number IMonth Day Year Facility Names Docket Number ($1 >

l l j AND. Unit 2 0 5 010 0 3 6 0 01 4 21 31 91 01 91 0 1l 01 01 3 - Of 01 Of b 21 31 91 01 u

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DTEkA"ING l lTHI5 REPORT 15 5UBMITTI.D PUR5UANT TO THE REQUIREMENT 5 OF 10 CFR 6; ,

MODE L9) N (Check one or more of the followinD) (ll) t POWER n 20.402(b) ~ 20.40b(c) i

~i 50.73(a)(2) iv) l~ 73.71(b)

LEVELI 20.405(a)(1)(1) 50.36(c)(1) 60.73(a)(2)(v)

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l'I 60.73(a)(2)(1) l' 50.73(a)(2)(ii) l~ l 50.73(a)(2)(viii)(A)I Abstract below and in Text, NRC f orm 5

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u1CEN5EE CONTACT FOR THIS LER (12)

Name p Telephone Number i Area i Dana Millar, Nuclear $8fety and Licensing Specialist LCode l 510111916141-13111010 COMPLETE ONE LINE FOR E ACH COMPONENT F AILURE DE5CRIBED IN TH]5 REPORT 03) l 1 Reportable j l l  : Reportable Cause System Componefit IManufacturer to NPRDS Cause System Component Manufgeturer to NPRD$ '

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I I l i I I I I i l I 1 I I I I I l l l SUPPLEMENT REPORT EkPECTliD (14) EkPECTED l Month Day Year

$UBM15510N ll r I'l Yes (If yes. complete Expected Submission Date) II) No DATE (15) I 1 I '

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AB51RACT (Limit to 1400 spaces, i.e., approximately fifteen sing 1E space typewritten lines) (L6)

On April 23, 1990, as a result of an inoperable process radiation monitor on Arkansas Nuclear One, Unit 1 (AND 1). Design Engineering performed a review of the process monitors and Super Particulate  :

lodine and Noble Gas (5 PING) monitors associated with various radiological effluent ventilation systems.

Design Engineering concluded that only the SP]NG monitors satisfied the requirements of Radiological Effluent Technical Specifications (RETS). The process monitors did not satisfy the Lower Limit of t Detection for Xenon 133 equivalent as.specified by the RETS. Previously both monitters had been used to ';omply with RET $. As part of the review Design Engineering discovered that in December 1976 it was identified that the system design of the ANO-1 Stack Monitor (RE 7400) may be inadequate to obtain ,

accurate samp e results. Actions were initiated to replace RE 7400, however, due to changes in regulatory requirements ..ssociated with the Three Mile Island accident the SFING monitors were installed and

, RE 7400 was not replaced. In January 1985 the RETS amendment was ef fective. Following this amendment, due to a lack of understanding of operability as it related to the regulatory requirements Operations Management decided that either monitor was capable of satisfying Technical Specifications. After Design Engineering completed the evaluation of the monitors, in April 1990 AND-1 and ANO-2 Operations Management notified their staffs that only the $ PING monitor could satisfy the RETS.

1

Form 1063.01B hkC. form 366A U.$. Nuclear Regulatory Comission (6 89) Approved OMS he. 3150 0104 Expires: 4/30/92 LICLN$(( [ VENT REPORT (L[R) T[XT CONTINUATION FACILITY hAME (1) (DOCkEl NUMblR (2) l L E R NJM[.ER (H j FAGL (3) l l l l5equential l kevisioni Arkansas Nuclear One, Unit One l l_ Year Number Number l 1015!010101 3! 11 31 91 0 -

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01 Ol01210Ff013 TEAT (If more space is required, use adaltional NRC Form 366A's) (17)

A. Plant Status At the time of identifying this condition Arkansas Nuclear One Unit One (AND 1) was operating at approximately 80 percent of rated thermal power. Reactor Coolant $ystem (RCS) [ AB) temperature was about 579 degrees fahrenheit and RC$ pressure about 2155 psig. AND, Unit Two (AND 2) was operating in Mooe 1 (Power Operation) at approximately 100 percent of rated thermal power. RC$

temperature was about 580 degrees Fahrenheit and RC$ pressure about 2250 psia.

B. [ vent Description The AND 1 and AND 2 Radiological [ffluent Technical Specifications (RET $) require that various ventilation flow pathways be monitored with an operable radiation monitor anytime the potential exists for a release to occur via that pathway (i.e., whenever the ventilation system is c,perating)*

Two monitors, a process radiation monitor and a Super Ferticulate lodine and Noble Gas ($ PING) monitor, are available to monitor several of the ventilation pathways. For ANO 1, the Auxiliary Building, $ pent iuel Pool Area and Reactor Building Purge ventilation systems have the capability of being monitored for radiological activity by either monitor. For AND 2 either monitor is available for the Containment Forge, $ pent Fuel Aree Auxiliary Building Area and Auxiliary Building Extension ventilation systems. As a result of an inoperable process radiation monitor on AND 1. Design [ngineering performed an evaluation of the process radiation monitors and the SPING monitors. Based upon the results of this evaluation, on April 23, 1990, it was concluded that only the $ PING monitors satisfied the requirements of RET $. The Operation staffs of both ANO 1 and ANO 2 were informed that the process radiation monitors no longer could be utilfred to satisfy RETS and that the $ PING monitors were the only monitors which did satisfy RETS.

As part of the review performed by Design [ngineering it was discovered that in December 1976 the system design for the AND 1 Stack Monitor (R[ 7400) was identified to possibly be inadequate to ensure accurate samples were obtained. The AND-1 Stack Monitor is designed to have the ability to monitor three different ventilation pathways. With the design of the monitor, the sampling rates are not proportional to the exhaust rates which results in non-representative samples of particulates and a distorted indication for the gases. Additionally, the sample lines have numerous 90' bends which allow for plating out of the particulates prior to reaching the sample filters. Furthermore, the detector for the gas chamber is not very sensitive. The AND-1 Stack Monitor can be demonstrated to be operable by the required surveillance tests, however, the monitor cannot accurately sample more than one flow pathway at a time. Actions were initiated to replace the single monitor with three monitors. However, due to the change in regulatory requirements associated with the accident at Three Mile Island, the initial actions were not implemented and R[ 7400 was not replaced. The

$ PING monitors were installed in January 1981 to comply with the new regulatory requirements, however, were not utilized until January 1985.

On January 1,1985, the RETS amendment was ef fective for both ANO-1 and ANO 2. Upon implementation of the RITS amendment, Operations Management, at the time decided that either the process monitor or the SPING monitor could satisfy the requirements of the RETS. The AND-1 Stack Monitor continued to have the same problems which were identified in 1976. Additionally, the ANO 2 monitors manufactured by Westinghouse did not comply with RETS because the Lower Limit of Detection (LLD) for Xenon 133 equivalent was not as specified in the RETS and the sample collection system did not accurately account for variations in ventilation system flow rate.

C. Root Cause Due to a lack of management oversight and involvement, timely actions were not taken to replace Ri 7400. Operations Management at that time felt that the instrument was adequately performing its intended function.

When the RETS amendment was implemented for both AND-1 and AND 2, a review of the new Specifications was performed and it was concluded that the SPINGs met the intent of the RETS. However, Operations Management, at that time, did not feel that the amendment was limited to the $ PING monitors and, therefore, chose to continue to take credit for the process monitors, as well as the SPING monitors.

Therefore, if either monitor was operable, regardless of whether the $ PING or the process monitor, RETS compliance was assumed.

e NRC 4orm 3(M fore 2002.01B U.S. Nuclear Regulatory Commission (6 89) Approved OMB ho, 3150 0104 Expires: 4/30/92 LICtN$tt (VtW1 REPORT (LtR) TEXT CONTINUAI!ON FACILIIV NAML (1) 4DDCkl1 NJMb[R (2) l ,[ R NUM[.IR (6) l FAGE (3)

Arkansas Nuclear One, Unit One l l 1 i Aequential,i IRevisioni l l_ Year Number Number l 10l$f010101 31 11 31 91 0 +-

01 01 3 --

01 Ol01310Fl013 TEXI (if more space 15 required, use additional NRC form 366A's) (17)

In 1976 and 1985 when the process monitors were questioned, there was not a clear understanding of the operability requirements and associated regulatory requirements for the monitors, lherefore, the decision made by Operations Management did not consider ope nbility as it related to regulatory requirements and incorrect monitoring instrumentation for the radiological effluent ventilation systems were utilized.

D. . Corrective Actions Based upon the findings of Design Engineering and the subsequent reviews, Operations Manageaient for AND 1 and AND 2 informed their staffs that the process monitors could not be used to comply with RE15. Logs on each of the monitors are periodically taken to track radiological activity and verify optrability of the monitors. The logs it,r both units. AND 1 and AND 2, have been changed to clearly annotate that only the SPING monitor satisfies R[IS requirements.

An operability determination process was implemented in the April 1989 to provide guidance in determining operability of components as they relate to system design and regulatory requirements.

This should help prevent recurrence of events similar to this.

L. Safety $1gnificance Although the AND 1 Stack Monitor may not have been adequate to obtain accurate samples, any unexpected increase in radiological activity could have been detected with the monitor. The process used to account for gaseous activity was to analyre a sample of the gas and ratio it with the weekly berage of the readings from RE 7400 and compare it to the allowat'le limits. During this time period the actual releases offsite cannot be reanalyted, however, ample margin existed to be relatively confident that no limits were exceeded.

Numerous times since the issuance of the RETS amendment for ANO-1 and AND 2, a process radiation monitor has been utilized to satisfy the requirements of RET $, Although the process monitors lack the sensitivity at the lower limit of detection for Xenon 133 and the data processed isn't as accurate as the SPING data, the ventilation flow pathways were still monitored, and any unexpected increase in radioactivity could have been detected. The semi annual radiological effluent reports submitted since January 1985 have uttitted data obtain from 1,he $ PING monitors. The safety significance of this condition is, therefore, considered to be minimal.

F. Basis for Reportability This condition Technical is reportable pursuant to 10CFR50.73(a)(2)(1)(B), as a condition prohibited by Specifications.

G. Additional Information There have been no previously reported events in which the incorrect instrumentation was used to satisfy Tecnnical Specification requirements.

Energy Industry Identification System (E!!$) codes are identified in the text as [XX).