ML13331A850

Forwards Request for Addl Info Re 851121 Event,Per 860305 Meeting W/Util.Schedules for Response Requested

ML13331A850
Person / Time
Site:	San Onofre
Issue date:	03/25/1986
From:	Lear G Office of Nuclear Reactor Regulation
To:	Baskin K Southern California Edison Co
References
NUDOCS 8603260521
Download: ML13331A850 (5)

Text

MAR 2 5 1986 Docket No. 50-206 Mr. Kenneth P. Baskin, Vice President Nuclear Engineering Safety and Licensing Department Southern California Edison Company 2244 Walnut Grove Avenue PO Box 800 Rosemead, CA 91770

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION As a result of the March 5, 1986 meeting between the staff and Southern California Edison Company, the staff has found that additional information is required related to the November 21, 1985 event.

Please provide responses to the enclosed questions. Schedules for these responses should be developed with your NRC Project Manager.

The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, George E. Lear, Director Project Directorate #1 Division of PWR Licensing-A

Enclosure:

As Stated cc:

See next page 8603260521 860325 PDR ADOCK 05000206 S

PDR Office:

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RDudley/tg RBa&

hoan GLear Date:

03/).,/86 03/?//86 03 86 03/-4786

Mr. Kenneth P. Baskin San Onofre Nuclear Generating Station Southern California Edison Company Unit No. 1 cc Charles R. Kocher, Assistant Joseph 0. Ward, Chief General Counsel Radiological Health Branch James Beoletto, Esquire State Department of Health Southern California Edison Company Services Post Office Box 800 714 P Street, Office Bldg. 8 Rosemead, California 91770 Sacramento, California 95814 David R. Pigott Mr. Hans Kaspar, Executive Director O'rrick, Herrington & Sutcliffe Marine Review Committee, Inc.

600 Montgomery Street 531 Encinitas Boulevard, Suite 105 San Francisco, California 94111 Encinitas, California 92024 Mr. Stephen B. Allman San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 Resident Inspector/San Onofre NPS c/o U.S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 Director Energy Facilities Siting Division Energy Resources Conservation &

Development Commission 1516 -

9th Street Sacramento, California 95814 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane Walnut Creek, California 94596

ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION

1. System Design/Operating Data

a. At steady state 92% rated thermal power (RTP), what are the feed flows (in lb/hr and gpm), pressures, and temperatures encountered at the feed pump discharge check valves (12") and the steam generator feed line check valves (10")? How was this data obtained?

b. What were the above data at steady state 100% RTP? How was the data obtained?

c. What is the minimum steady state flow rate, along with pressures and temperatures, that these valves encounter?

d. Clearly indicate the source and reliability of the Atwood Morrill valve data used in the redesign calculations.

2. Valve Technical and Performance Requirements

a. What was the design basis for the 10" and 12" valves in terms of flows, port size, obturator weights, pressure, and temperatures for both the MCC-Pacific and Atwood-Morrill valves? How does this differ from actual values?

b. What are the acceptable operating ranges for the new valves and what is the impact on plant/system operations?

c. What are the maintenance, installation, and operation requirements or guidelines provided by MCC-Pacific and Atwood-Morrill?

d. Will the new valves be modified to include operator assists or position indicators?

e. What are the "enhanced" surveillance and maintenance requirements and their basis for the Atwood-Morrill valves? Are they from or concurred by the manufacturer?

f. What are the Atwood-Morrill bonnet and packing torque values?

g. Where is the Atwood-Morrill actual hinge and disc combination center of gravity?

3. Vibratory Loads

-2

a. Clarify the method of development of the factor that turbulence loads from upstream components will not exceed 10% of disc weight?

b. The ISA Handbook of Control Valves provides recommendations on installation. Why or why can't these locational restrictions be correlated to check valves?

c. Atwood-Morrill recommends not locating check valves within specific distances of turbulence producing components. What is the basis for deviating from these recommendations?

4.*

What was the procurement history for the original valves and spare parts?

5. Were other types of valve designs considered for this application (e.g.,

tilting or damped disk)? What is the basis for choosing a swing check design?

6. What flow band can result in a valve disk flutter problem for each of the new valves?

7. Include a discussion on how the auxiliary feedwater operating flow band avoids disk flutter or vibration from other check valves in the main feedwater and auxiliary feedwater piping system.

8. Clarify the statement made in handouts used at the January 31, 1986 meeting with the NRC that an error existed in Crane Technical Paper 410 that may have contributed to this problem.

9. Submit the results of the re-analysis of the auxiliary feedwater (AFW) initiation timing requirements that determine how quickly the emergency diesel generators must be manually loaded in the case of a loss-of-offsite power and a single failure of the turbine-driven AFW pump.

10.

Document the basis for your conclusions stated in the March 5, 1986 meeting regarding the possible effects on the November 21, 1985 event if the diesel generators had been designed to automatically load upon loss of offsite power.

11.

Document the operator actions needed to:

a. Transfer loads from the onsite power sources (diesels) back to an offsite power source when offsite 'power is recovered, and

b. load the diesel generators to provide motive power to the electric-driven auxiliary feedwater pump in case of loss-of-offsite power.

MAR 2 5 1986 DISTRIBUTION:

Docket Files NRC PDR Local PDR R. Dudley R. Ballard J. Milhoan G. Lear P. Shuttleworth L. Harmon E. Jordan B. Grimes J. Partlow T. Barnhart (4)

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