ML20245H100

Provides Status of Mods Re Four Outstanding Control Room Human Engineering Discrepancies (Heds) Identified During Unit 1 Crdr Program.Hed TA-03 Resolved & Hed A1-02 Reevaluated & Priority Lowered from Priority 2 to 4

ML20245H100
Person / Time
Site:	Limerick
Issue date:	06/19/1989
From:	Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8906290397
Download: ML20245H100 (3)

Text

_

o s

.. PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA A, PA.19101 (215) e 4 b4000 June 19, 1989 Dochet No. 50-352 50-353 ,

License No. NPF-39 I Construction Permit No. CPPR-107 j i

l l

1 U. S. Nuclear Regulatory Commission Atta: Document Control Desk Washington, DC 20555

SUBJECT:

Limerick Generating Station, Units 1 and 2 Control Room Human Engineering Discrepancies Commitment Revisions Gentlemen:

The purpose of this letter is to provide the status of modifications associated with four outstanding Control Room Human Engineering Discrepancies (HEDs) that were identified during the Limerick Generating Station (LGS) Unit 1 Control Room Design Review Program. These HEDs (Nos. Al-02, TA-03, TA-20, and TA-22) were reported as part of the Control Room Design Review Final Report, which consisted of an initial and two supplemental submittals. In this Report, the Philadelphia Electric Company committed to resolving these HEDs by the end of the Unit 1 Second Refueling Outage. The Second Refueling Outage was completed on May 19, 1989, and the current status of these HEDs is as follows.

o HED No. TA-03 (" Reactor Pressure Scale Multipliers") has been resolved.

o HED No. Al-02 (" Separation of Warning Wiring") has been re-evaluated and its priority has been lowered from

[ Priority 2 to Priority 4. Accordingly, no further g, corrections will be made.

&nz 581 o HED No. TA-20,(" Suppression Pool Level Alarm") was not 00 resolved during the Second Refueling Outage, and has been me rescheduled to be corrected during the Unit 1 Third g Refueling Outage.

o o HED No. TA-22 ("Drywell Temperature Alarm Indication")

l $< was not resolved during the Second Refueling Outage, and l g has been rescheduled to be corrected during the Unit 1 g$@I l ea Third Refueling Outage.

Cat S,pl I

\

., Docum:nt Control Desk June 19, 1989 Page 2 The following provides our justification for rescheduling or reprioritizing HED Al-02, TA-20, and TA-22.

1) HED No. Al-02 (" Separation of Warning Wiring") was reported to the NRC by our letter dated June 25, 1984, which submitted the initial Control Room Design Review Final Report. The HED was categorized as Priority 2 (Low Safety Significance), and identified a concern with warning and diagnostic alarms not being separated from advisory and informational displays on certain Control Room panels. Since becoming operational, Unit 1 operators have been trained on, and are familiar with the location of the alarms as installed. Therefore, relocation of these alarms at this time would be more disruptive than beneficial to plant operations, and is considered undesirable. Based on this determination, the corrective action identified as part of the original HED assessment will be revised to reduce the priority rating from Priority 2 (Low Safety Significance) to Priority 4 (No Significant Improvement).

Accordingly, the Unit 1 Control Room will retain the current alarm configurations.

2) HED No. TA-20 (" Suppression Pool Level Alarm") was reported to the NRC by our letter dated June 28, 1985, which submitted Supplement 2 of the Control Room Design Review Final Report. This HED concerned the lack of a suppression pool low level control panel alarm, and was categorized as Priority 2 (Low Safety Significance). The HED identified that an alarm would be advantageous since operator action is required in the event of a suppression pool low level, a condition requiring implementation of the Emergency Operating Procedures. However, station surveillance and test procedures have been established since Unit 1 became operational which require that suppression pool level instrumentation be monitored and recorded once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If suppression pool level is outside the normal range, specified in the surveillance test procedures, the Emergency Operating Procedures provide the necessary instructions for operators to take corrective actions. This procedural method for monitoring suppression pool level has proven adequate, and no operational difficulties have been experienced. In addition, suppression pool level is displayed on the Emergency Response Facility Data System (ERFDS) computer, and an abnormal condition is alarmed via a display color change.

Therefore, deferring completion of this HED until the Unit 1 Third Refueling Outage will not compromise plant safety.

3) HED No. TA-22 ("Drywell Temperature Alarm Indication")

was also reported to the NRC in Supplement 2 of the Control Room Design Review Final Report. This HED concerned the installation of a high average drywell temperature annunciator alarm, and was categorized as Priority 2 (Low Safety Significance). The HED identified that an alarm could assist in alerting Operations personnel of high average drywell temperature, a condition requiring implementation of the Emergency Operating Procedures.

However, {

since Unit 1 initial start-up, station procedures have been i established that require the drywell bulk average temperature be calculated manually during each shift (3 times daily). In addition, individual temperature sensors are monitored by the plant process computer. An abnormal condition is presented to the operator via ,

computer printer output. This procedural method of determining and i l

I E________________ i J

l Docum:nt Control Desk June 19, 1989 Page 3 l monitoring the average drywell temperature has proven adequate, and no operational difficulties have been experienced. Therefore, rescheduling completion of this HED until the Unit 1 Third Refueling Outage will not compromise plant safety.

The Unit 2 Control Room Design Review Pinal Report, which was submitted by our letter dated October 27, 1988, indicated that resolution of these sa_ ->s for Unit 2 was contingent on the Unit 1 implementation. Therefore, in order to maintain operator transparency, the HEDs that were not resolved (TA-20 and TA-22) on Unit 1 will not be corrected on the Unit 2 Control Room panels until the Unit 2 First Refueling Outage. The resolution of HED No. Al-02 for Unit 2 is consistent with that of Unit 1, as previously described in this letter, and therefore, will not be completed.

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

Very truly yours,

. h. M f

G. A. Hunger, Jr.f ,

Director Licensing Section Nuclear Support Divicion cc: W. T. Russell, Administrator, Region I, USNRC T. J. Kenny, USNRC Senior Resident Inspector, LGS

- _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .