ML13333A507

Forwards Addl Info Re Conditions & Results of Endurance Testing Performed on Auxiliary Feedwater Sys Pumps in Support of Responses to NRC Lessons Learned Task Force Requirements

ML13333A507
Person / Time
Site:	San Onofre
Issue date:	02/14/1980
From:	Baskin K Southern California Edison Co
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
RTR-NUREG-0578, RTR-NUREG-578, TAC-44652, TASK-10, TASK-RR NUDOCS 8002280588
Download: ML13333A507 (6)

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Southern California Edison Company P. 0. BOX 800 2244WALNUTGROVEAVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER, NUCLEAR ENGINEERING February 14, 1980 (213) 572-1401 AND LICENSING Director, Office of Nuclear Reactor Regulation Attention:

Mr. D. G. Eisenhut, Acting Director Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlmen:

Subject:

Docket No. 50-206 Additional Information in Support of Responses to NRC Requirements Related to the Three Mile Island Accident San Onofre Nuclear Generating Station Unit 1 By letter dated November 15, 1979 you provided NRC recommendations for the Auxiliary Feedwater (AFW) System at San Onofre Unit 1. Our response to these recommendations was provided by letter dated January 23, 1980.

One of the recommendations (Section X.13.3.2.2) required the performance of endurance testing of the AFW pumps. Based on the guidelines provided in the recommendation, the endurance testing was completed by January 25, 1980.

During recent telephone discussions with members of your Staff, subsequent to the completion of the endurance testing, we were advised that the guidelines under which the endurance testing should be conducted had been revised, and that a summary of the conditions and results of the endurance testing would have to be submitted to the NRC. The revised guidelines and a specific request for submittal of information obtained from the endurance testing was received by telecopy on January 25, 1980.

Submitted herewith as Enclosure 1 to this letter is the requested information obtained from the endurance testing. Where the information obtained from the endurance testing deviates from that requested by the revised guidelines, a basis for the deviation is also provided in Enclosure 1.

If you have any questions, or require additional information concerning the enclosure to this letter, please contact me.

Very truly yours,

'00 to Letter Dated February 14, 1980 from K. P. Baskin to D. G. Eisenhut A revision to guidelines for endurance testing of the AFW pumps, as described in Section X.13.3.2.2 of your letter, November 15, 1979, was telecopied to us on January 25, 1980.

The revised guidelines included requirements for a summary report of the endurance testing. The report requirements and our responses are provided below:

1)

Include a brief description of the test method (including flow schematic diagram) and how the test was instrumented (i.e., where and how bearing temperatures were measured).

Response

Special Operating Procedure #11, "Auxiliary Feedwater Pumps Endurance Run Test," was developed to establish test acceptance criteria for bearing temperatures and vibration.

The acceptance criteria were derived from the pump and pump driver manufacturer instruction manuals and pump head curves, or from similar test criteria which have been developed for the In-Service Pump Testing Program performed in compliance with ASME Boiler and Pressure Vessel Code,Section XI requirements.

Bearing temperatures were measured with a Wall Model Platinum 392 surface pyrometer held on the outside surface of the top of the bearing caps. Bearing vibration readings were measured with an IRD Model 306 vibration meter held on the outside surface of the bearing caps.

Each pump was tested individually using the flow path from the normal water source (Condensate Storage Tank) to all three steam generators via the emergency flow path as shown on Figure 1.

Each pump was operated for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

This duration complied with that recommended in your November 15, 1979 letter and exceeded the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> duration recommended in your revised guidelines.

At the conclusion of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> endurance tests, each pump was shut down and allowed to cool down for four hours. The pumps were then restarted and operated at design rated conditions for at least one hour. This cooldown and retest was consistent with that recommended in your November 15, 1979 letter (specific cooldown limits were not provided), but did not comply with specified cooldown limits recommended in your revised guidelines. Specifically, (1) we did not verify that the pumps cooled down until pump temperatures were reduced to within 20oF of their values at the start of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> endurance test, and (2) we did not allow the pumps to cool down for at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. However, the AFW pumps at San Onofre Unit 1 are relatively small (300 gpm -

steam and 240 gpm -

electric).

Thus, the pumps cool down more quickly than larger pumps and we consider the four hour cooldown period used for our endurance testing to meet the intent of the Staff recommendations. In addition, normal surveillance testing was successfuly completed from ambient conditions 15 days and 3 days following completion of the endurance testing for the electric and steam driven pumps, respectively.

-2

2)

Include a discussion of how the test conditions (pump flow, head, speed and steam temperature) compare to design operating conditions.

Response

Both pumps were operated at design rated discharge pressure and flow using pressure indications and the pump head curves. The steam driven pump was operated at design rated speed during normal plant operation with steam supplied from the steam generators at normal temperature (greater than 500 0F) and pressure.

3)

Include plots of bearing/bearing oil temperature versus time for each bearing of each AFW pump/driver demonstrating that temperature design limits were not exceeded.

Response

Pump and driver bearing temperatures were recorded at least every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> throughout the endurance tests. Plots of bearing temperatures (pump and driver) versus time for the electric and steam driven AFW pumps are shown on Figures 2 and 3, respectively. All bearing temperature readings remained within the acceptance criteria during the endurance tests.

4)

Include a plot of pump room ambient temperature and humidity versus time demonstrating that the pump room ambient conditions do not exceed environmental qualification limits for safety-related equipment in the room.

Response

The AFW pumps are located in an open area under the west feedwater heater deck.

The exhaust from the steam-driven AFW pump is piped to a remote outside location. Therefore, ambient conditions (temperature, humidity) are not substantially affected by AFW pump operation. Actual temperature and humidity conditions were not measured during the endurance testing.

5)

Include a statement confirming that the pump vibration did not exceed allowable limits during tests.

Response

Pump and driver bearing vibration readings were recorded at least every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> throughout the endurance tests. All vibration readings remained within the acceptance criteria.

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