ML20042E893

Responds to Violation Noted in Insp Rept 50-278/90-01. Corrective Actions:Automatic Depressurization Sys Logic Sys Functional Tests Will Be Revised to Include Guidance in Unique Application of Test Lights

ML20042E893
Person / Time
Site:	Peach Bottom
Issue date:	04/27/1990
From:	Franz J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9005040035
Download: ML20042E893 (3)

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s . g PHILADELPHIA ELECTRIC COMPANY PEACH BOTiUM A1DMIC FOWER STATION R D 1, Box 208 Delta. Pentnyhania 15314 rexm sorrms-rua etm an os a scsttewe Pl7) 4 $4*0l4 April 27, 1990 10 CFR 2.201 Docket Hos. 50-277 50-278 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

SUBJECT:

Peach Bottom Atomic Power Station - Units 2 & 3 Response to Notice of Violation (Inspection Report 50-277/90-01; 50-278/90-01)

Dear Sir:

Attached is our response to the subject Notice of Violation. This violation invoked failure to perfcrm testing required by Technical Specification 4.5.E.2.

In the cover letter to the subject inspection report, you indic6ted that inadequate review and disposition of deficient surveillance test results appeared to cause the Technical Specification violation. You asked us to include our corrective actions to address this apparent cause. We have determined that an inadequate procedure and inadequate troubleshooting were the causes of this violation. However, because of recent events involving inadequate review of the results of 2 surveillance tests, guidance will be developed for Operations personnel review of completed surveillance tests so that timely and proper Technical Specification actions can be taken on deficient test results.

If you have any questions or require additional information, please do not hesitate to contact us.

Sincerely, w ,. /

la tit Manager Attachment cc: R. A. Burricelli, Public Service Electric & Gas T. M. Gerusky, Commonwealth of Pennsylvania J. J. Lyash, USNRC Senior Resident inspector ,

T. E. Maaette, State of Maryland T. T. Martin, Administrator, Region 1 USNRC H. C. Schwemm Atlantic Electric J. Urban, Delmarva Power {

9005040035 900427 PDR Q ADOCK 050002$ PDC  %(

Attachment Response To Notice of Violaticn 90-01/01 Restatement of Violation Unit 2 Technical Specification (TS) 4.5.E.2 requires that when one valve of the Automatic Depressurization System (ADS) is inoperable, the ADS subsystem actuation logic for the other ADS valves and the HPCI subsystem shall be demonstrated to be operable immediately and at least weekly thereafter.

Contrary to the abSve, on February 7, 1990, failure of Surveillance lest ST 1.8, " Automatic Depressurization System (ADS) 'A' Logic System functional "

Revision 23, demonstrated that ADS valve "K" was inoperable. The licensee did not perform the testing required by 15 4.5.E.2 until February 12, 1990, due to misinterpretation of the test results.

Background

During performance of an 'A' ADS Logic System functional Test (LSF1) on 2/7/90, a logic test light that indicates actuation of a relay contact for the 2K ADS valve did not turn on. Initial troubleshooting proved proper relay contact operation. The LSFT procedure stated that the light indication proves initiation logic functionality but did not mention that it also proves solenoid valve coil functionality. It was thought at that time that the light

, did not turn on because the logic test light socket was bad. The logic test light socket is difficult to directly troubleshoot because of its location inside the control panel. Because of the risk in checking the light socket and the potential to inadvertently lift an ADS valve during power operation and because the procedure did not state that the light also indicates the n ndition of the solenoid coil, testing of the socket was planned to be postponed until the upcoming outage (i.e., early March). The ADS circuitry is different from other Emergency Core Cooling Systems (ECCS) circuitry in that, in ADS, the logic test light will light only if there is continuity through the solenoid valve coil in addition to having power to the circuit and the relay contact being closed. It was incorrectly thought that the DC solenoid valve (and therefore the 2K ADS valve) was operable since a voltage reading was read through the solenoid valve coil. Apparently, this voltage reading was from induced voltage.

On 2/12/90, the LSFT on the 'B' ADS logic revealed i similar light problem concerning the corresponding relay contact and light on the 'B' logic.

Troubleshooting was again performed on the nC circuit. Because of the similarity to the problem experienced with the 'A' ADS logic, additional ttoubleshooting techniques were used. This additional troubleshooting identified an open circuit to the solenoid valve coil on the 2K ADS valve.

This was determined by jumpering the solenoid valve coil circuit which caused the light to turn on. The open circuit causes the 2K ADS valve to be inoperable.

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. Corrective' Steps Taken and Results Aceinved

- Troubleshooting on 2/12/90.properlyJidentified the inoperable 2K' ADS valve and appropriate Limiting Condition of Operation (LCO) and surveillance

-actions were-taken.

l - This event was discussed =in System Engineer group meetings. The System-

' Engineers and their Supervision were made aware of the differences between.

the logic;of. ADS circuitry and other ECCS logic circuits as well as thel a possibility of encountering induced voltages in circuits while 1

. troubleshooting.-  ;]

Corrective Steps:That'Will'Be Taken To Avoid'Further Violations -

=1. ADSLLSFTs will be revised to include guidance that intthis unique l application offtest lights,-the purpose'of'the logic test-lights is-to.  :

show: continuity'through the ADS solenoid-as-well as to indicate proper logic operation. '

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2. Ot_her system logics will be reviewed to determine if multiple purpose indication lights are used in other surveillance tests. Tests will be- ]q revised..if required to provide;similar guidance. '

3._ Training will be'provided to System. Engineers. This. training will increase the system engineers' understanding of how tottroubleshoot. system circuitry including DC circuits'and-the possibility of: encountering. .i induced voltages.- Similar training.'ill w be included in the: training-program for.0perations Shift-Technical-Advisors. ]

Date When Full Compliance-was' Achieved i

Full compliance was achieved on 2/12/90 when the ADS subsystem 1 actuation- 9 logic for'the other ADS valves and the HPCI subsystem were-demonstrated to be.  !

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