ML20055H964

Responds to NRC 900629 Ltr Re Violations Noted During Special Safety Sys Functional Insp on 891030-1130.Corrective Action:Util Will Review & Revise Operating & Calibr Procedures by 901031

ML20055H964
Person / Time
Site:	San Onofre
Issue date:	07/27/1990
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9007310207
Download: ML20055H964 (5)

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, ,. fi,a Southem Calikwnla EotAvr Chmpany 23 PAkntR STREET I inveNE. CALironNIA 92718

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. July 27, 1990 2 *II.~.I'o'.

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133 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C.

20555

! Gentlemen:

Subject:

Docket No. 50-361 and 50-362 Reply to a Notice of Violation San Onofre Nuclear Generating Station, Units 2 and 3 i

Reference:

Letter, S. A. Richards (NRC) to Mr. Harold B. Ray (SCE),

dated June 29, 1990 The referenced lett.u forwarded a Notice of Violation which resulted from the special Safety ir tem e Functional Inspection (SSFI) conducted by the NRC's Office of Nuclear Reactor Regulation between October 30 and November  :

L 30, 1989. In accordance with the provisions of Appendix A of the subject Notice of Violation, the enclosure provides the Southern California Edison (SCE) response.

If you require any additional information, please call me.

Sincerely, 1

Enclosure i cc: J. B. Martin (Regional. Administrator, NRC Region V)

C. Caldwell (NRC Senior kesident Inspector, San Onofre) 8 9007310207 900727 PDR il1 7 O ADOCK 05000361 1 PDC

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ENCLOSURE REPLY TO A NOTICE OF VIOLATION Enclosure A to Mr. S. A. Richard's June 29, 1990 letter states in part:  !

• A . 10 CFR Port 50, Appendix B, Criterton til requires that measures  !

be established to ensure that the design basis is correctly translated into specificottons, drawings, procedures, and  ;

instructtons. '

• 10 CFR Port S0, Appendix B, L 'iterion V requires that ,

octtvities offecting quality be accompiished in accordance with.  ?

oppropriate instructions or procedures. '

' Contrary to the above. . .

• 2. At the time of the inspectton, the colibrotton procedures for the diesel fuel oil day tank and storage tank level indicators were inappropriate in that they did not include the information necessary for equating indicated level in the tanks to the octual level or ) tel volume, in addition, procedures for calibrating tht fuel oil storage

• tank level indicators were insufficient to ensure that the storage tank volumes required by the Technical Specificottons were being maintained."

' "This reply should... address, for violation A.2 above: (1) the basis for the conclusion in your (SCE) Aoril 24, 1990 letter that the diesel fuel oil storage tanks have sufficient margin to accomodate any additional errors that may be identified; and, (2) specifically, the basis for SCE's confidence that the fuel inventory requirements stated in Technical Specificotton 3.8.1 are met at ali times. "

i 24, 1990 letter from F. R. Nandy (SCE) to the i

l As Documentdiscussed Controlin Deskthe Ap(rilNRC),SCEcommittedto i

... review the diesel fuel storage tank level setpoints and colibrattons in conjunctton with the overoll setpoint reconstitution i program. The' evaluation of the storage tank level setpoints is expected to be complete by September 1,1990. Weareconfidentthat there is sufficient margin in the fuel storage tank calculations to occomodate any errors that may be identified in this effort."

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2 l tackaround The San Onofre diesel fuel oil system for each Unit is comprised of: (1) a diesel fuel oil storage system which contains two interconnected Diesel Fuel Oil Storage Tanks (DFOST); and, (2) a Diesel Fuel Oil Day Tank (DF0DT) for each diesel generator. The DFOST system is required by TS 3.8.1.b.2 to maintain a minimum volume of 47,000 gallons in Modes 1-4, and TS 3.8.2.b.2 to maintain 37,600 The DF0DT is required by Technical Specifications (TS)3.8.1.b.1 gallons and in Modes 5-6.

3.8.2.b.1 to contain a minimum volume of l

325 gallons (all Modes).

The DFOST system and DF0DT are equipped with level transmitters, which use reed switches, actuated by a magnet enclosed in a float assembly, to provide a signal that-is proportional to the level of fuel oil in the tank. The DFOST system has a Lo-level alam which alarms it the Control Room. The DF0DT is automatically replenished from the DFOST system by a fuel transfer ,

pump whenever the DF0DT Lo-level setpoint is reached.

During the SSFI, SCE procedures were reviewed, and as discussed in the inspection report, the following items were noted in the operations and calibration procedures:

(1) Operations procedure was reviewed and found 5023 not2-13.

to: a(" Diesel directlyGenerator Operation",

equate indicated level to actual tank level (inches))or to fuel volume (gallons);

and (b) contain explicit guidance for determining at what point the level indicator readings wera sufficient to ensure that the minimum storage ta:ik volumes required by the Technit.a1 Specifications were satisfied.

(2) Instrumentation and Control (I&C) procedure S0123-11-9.245, "3 EMS 36000 and 51000 Series TLI S Transmitter and Indicator Calibration",ystem Modular was reviewed Reciever and found not to: (a) contain a five point calibration method for the DF0DT; (b) adequately relate manual " stabbing" measurements of the DFOST to the transmitter measurement of tank level; and (c) indicate the applicable method for calibrating the instrument readout in percent of tank volume.

When SSFI inspectors discussed these items with SCE personnel, the design basis of the DFOST and DF0DT setpoints, and the bases of operating and calibration procedures, was apparently not clearly communicated.

Prior to the SSFI, SCE had initiated a design basis reconstitution program, which includes a setpoint reconstituion program. The setpoint reconsitituion program and its associated standard, conforms to the recently approved Instrumentation Society of America (ISA) setpoint methodology.

During the SSFI, DFOST and DF0DT calculations were also under development.

3 The following design calculations have now been completed:

(1) M-0016-005, "DFOST Volume", dated March 16, 1990. This j calculation established the DFOST system useable volume to be in excess of 54,000 gallons. The actual DFOST system useable volume is therefore more than 15% greater than the TS minimum requirement of 47,000 gallons requ red in Modes 1-4 (and more than 43% greater than the 37,600 gallons required in Modes 5-6). l (2) M-0016-008, "DG Onsite fuel Oil Requirements", dated March 16, 1990. This calculation was performed in order to re-establish the design requirements of the DFOST system. This calculation established that: (a) the maximum fuel consumed during a Mode 1-4 accident scenario is 40,881 qallons; and (b) the maximum fuel consumed during a Mode 5-6 ace dent scenario is 33,368 gallons.

Therefore, the TS Mode 1-4 minimum of 47,000 gallons and Mode 5-  :

6 minimum of 37,600 gallons, are conservative. l (3) J-]EA-002, " Fuel Oil Level Setpoints for Diesel Generator Storage Tanks", which is 11 the final approval process (expected '

to be issued by August 10,. 1990). This calculation was performed to determine the adequacy of existing DFOST Lo-level setpoints with respect to the TS minimum volume requirements.

This calculation confirmed the DFOST Mode 1-4 Lo-level existing

, setpoint of 75% (which ecuates to 118 inches from the bottom of I the tank), is sufficiently conservative with respect to the TS 47,000 gallon minimum volume which occurs at 114.75 inches. The calculation also confirmed that the DFOST Mode 5-6 procedural limit of 62% (which equates to 98.37 inches) assures that the TS 37,600 gallon minimum volume, wMch occurs at 93.42 inches, will be maintained. ,

Response

SCE has reviewed the SSFI findings related to the DFOST and DF0DT, and has taken or will be taking, the following actions with regard to operations and l calibrations procedures:

l (1) On November 22, 1989, SCEissuedTemporaryChangeNotice(TCN) 9-20 to procedure S023-2-13 to provide guidance to ensure that adequate DF0DT fuel oil volume was maintained.

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(2) In order to incorporate the infomation developed in i calculations M-0016-005, M-0016-008, and J-JEA-002, SCE will review and revise as necessary, operating and calibration.

procedures by October 31,1990, to include: information equating, i indicated level in the tanks to the actual level and/or fuel l volume; explicit guidance for ensuring that the storage tank  ;

volumes required by the Technical Specificatione are being i maintained; a five point calibration method for the DF00T; relate ' manual " stabbing" measurements of the pr0ST to the transmitter measurement of tank level; and indicate the i applicable method for calibrating the instrument readout in >

L percent of tank volume.

With regard to the basis for SCE's confidence that diesel fuel inventory requirements have been satisfied:

(1) Calculations J-JEA-002, M-0016-005 and M-0016-008, discussed above, indicate sufficient excess diesel fuel oil level exists (i.e., greater than 3.25 inches for Modes 1-4 and 4.95 inches for Modes 5-6) to accommodate instrument uncertainties associated with the DFOST level instruments.

(2) A review of surveillance results by the Nuclear Oversight Division indicate the DFOST system diesel fuel cil level has not t been below 82% (i.e., level greater than 127 inches for a fuel l oil volume greater than 50,000 gallons), and the Lo-level setpoints and procedural limits are conservative with respect to instrument uncertainties including potential calibration errors. -

Therefore, SCE believes that the fuel inventory requirements stated in Technical Specification 3.8.1 have been maintained.

The aforementioned calculations complete SCE's review of the DFOST/DF0DT t operating and calibration procedures and setpoints, in conjunction with the overall setpoint reconstitution program currently in progress. As requested in Mr. S. A. Richard's letter dated June 29, 1990 SCE has provided to the ,

NRC Senior Resident Inspector copies of M-0016-005 and P.-0016-008.

Calculation J-JEA-002 is expected to be completed by August- 10,1990, and-will be provided to the NRC Senior Resident Inspector upon issuance.

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