ML18102B392

Provides Info Concerning Recent Rev & Validation of 2-EOP-LOCA-3, Transfer to Cold Leg Recirculation.

ML18102B392
Person / Time
Site:	Salem
Issue date:	06/13/1997
From:	Storz L Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LR-N970376, NUDOCS 9706180352
Download: ML18102B392 (4)

Text

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• Public Service Electric and Gas Company Louis F. Storz Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-5700 Senior Vice President - Nuclear Operations JUN 13 1997 LR-N970376 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 VALIDATION OF THE TRANSFER TO COLD LEG RECIRCULATION EMERGENCY OPERATING PROCEDURE SALEM GENERATING STATION NO. 2 FACILITY OPERATING LICENSES DPR-75 DOCKET NOS. 50-311 Gentlemen:

As discussed during the telephone conversation held on June 10, 1997, Public Service Electric and Gas (PSE&G) is providing the following information concerning the recent revision and validation of the "Transfer to Cold Leg Recirculation" Emergency Operating Procedure (EOP), 2-EOP-LOCA-3. The changes to procedure 2-EOP-LOCA-3 were initiated due to concerns with possible interruption of Emergency Core Cooling System (ECCS) pump flow during the transfer from the injection phase of Loss of Coolant Accident (LOCA) mitigation to the cold leg recirculation phase as a result of certain LOCA events and single failure scenarios. To eliminate the possibility of interruption of ECCS pump flow, PSE&G performed changes to procedure 2-EOP-LOCA-3 to minimize the affect of equipment single failures (which lead to decreased time available to perform the switchover from injection to recirculation) and to streamline .the operator actions to reduce the time necessary to complete the switchover.

During the development of the EOP revision, a general review of the Salem Simulator (which is a replica of the Unit 2 control room) layout determined that equipment was arranged logically to reduce the occurrence of an operator manipulating the wrong equipment. For example, the switches for the containment sump isolation valves (SJ44 valves) are grouped together away from other switches on the control room panel. The valve power lockout switches that are required to be operated during the switchover are grouped together (in a row) on the control room panel and begin with the same nomenclature (SJ6#).

Other valve lockout switch manipulations that were not required to complete the initial switchover to the recirculation mode of operation were moved to a later step in the procedure to decrease . ")

actual operator response time. , li l'1.\. Printed on I\Ulll

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Do,cument Control Desk 2

• JUN 13 1997 LR-N970376 As part of development of EOP revisions, a verification and validation (V&V) of the EOP changes are performed (this V&V effort is consistent with the guidance provided in NUREG-1358). The V&V of the EOP changes identified that certain decisional procedure steps did not provide clear guidance to the operators. The operators either did not understand the intention of the step or the step required the operator to determine which train of equipment to manipulate. As a result of this feedback, additional enhancements were made to the EOPs that resulted in clearer decisional steps and provided the operators with specific guidance to manipulate the proper train of equipment.

The following is an example of a step that was changed. The original revision of the EOP contained a step that asked the operator if both containment sump isolation valves were open. If the answer was no, the operator was directed to stop the Residual Heat Removal (RHR) pump associated with that train, close the associated RH4 valve, and open the associated containment sump isolation valve. When the containment sump valve opened the operator was to start the associated RHR pump. This required the operator to determine what equipment to operat~ during performance of the EOP. Based on the feedback provided by the operators and the amount of time the operators were taking to perform the above actions, changes were made to this step in the procedure. The decisional step was revised to ask if a specific containment sump isolation valve is open, and if not, specific steps were provided to the operator to manipulate the equipment associated with the train that was affected. This change allowed the operators to progress through the EOP more quickly with less chance of error.

Also as part of the training of the operating crews, as mistakes are encountered in the performance of an EOP, a review of the reason for the mistake is performed. This information is provided to the other operating crews, as necessary, to miriimize similar errors. Besides the simulator training provided to the operating crews, classroom training is also being provided to review the purpose and basis of procedure 2-EOP-LOCA-3.

As a result of the current revision to procedure 2-EOP-LOCA-3, the operators are performing the switchover from the injection mode of accident mitigation to the recirculation mode in approximately 5 minutes. Compared to the approximately 8 to 9 minute average for performance of the previous revision of 2-EOP-LOCA-3, the current revision has reduced the actual operator response time to complete the switchover alignment by approximately 40%.

In addition to the recent changes to EOP-LOCA-3 discussed above, during the last major revision to EOP-LOCA-3 the procedure was reformatted, based on comments from the V&V team. This V&V team included a member that has a Ph.D. specializing in human factors, who 95-4933

r Do.cumen't Control Desk 3

• JUN 13 1997 LR-N970376 reviewed the proc~dure for the adequacy of the procedure format with respect to human factors. During this last major revision to the EOP, the procedure was revised, as discussed below, to facilitate the transition from one step in the procedure to a new section (that may be several steps down in the procedure}. After the initial steps for alignment to recirculation are completed, the operators check the plant status (Vital Bus, Service Water pump, and Component Cooling heat exchanger availability} to determine the appropriate step to transition to in the procedure to complete the switchover alignment.

The procedure was reformatted such that:

• The first step of each transition to a new section in the EOP starts at the top of a separate page in the flowchart, minimizing transitional errors.

• The steps to complete the alignment for switchover associated with the existing plant status (Vital Bus, Service Water Pump, and Component Cooling heat exchanger availability} are contained on one flowchart (one page of the procedure}, minimizing transitional errors.

• Each section that is transitioned to in the EOP contains only the specific actions necessary, based on the existing plant status, to complete the switchover alignment. Unnecessary steps, such as starting a pump on a de-energized bus, have been eliminated. This significantly streamlined the procedure.

Based on the above information, the verification and validation performed by PSE&G of current 2-EOP-LOCA-3 revision (and the last major revision} ensures that the possibility of operator errors during the performance of this EOP has been minimized.

If you have any concerns regarding this submittal, please contact us.

Sincerely, ~

~~ ;roo 95-4933

Do~ument Control Desk 4

• JUN 1 3 1997i LR-N970376 C Mr. H. J. Miller, Region I Administrator U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. L. Olshan, Licensing Project Manager - Salem U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852 Mr. C. Marschall (X24)

USNRC Senior Resident Inspector Mr. K. Tosch, Manager, IV Bureau of Nuclear Engineering 33 Arctic Parkway CN 415 Trenton, NJ 08625 95-4933