ML13330A062

Discusses Completed Review of NRC Forwarding Five Addl Items Resulting from post-TMI Reviews.Forwards Commitments to Meet Implementation Requirements for Items 1-5

ML13330A062
Person / Time
Site:	San Onofre
Issue date:	06/13/1980
From:	Baskin K Southern California Edison Co
To:	Crutchfield D Office of Nuclear Reactor Regulation
References
TAC-44128 NUDOCS 8006190584
Download: ML13330A062 (7)

Text

• I Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE

ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER, NUCLEAR ENGINEERING June 13 1980 (213) 572-1401 AND LICENSING J n 1

9 Director, Office of Nuclear Reactor Regulation Attention: D. M. Crutchfield, Chief Operating Projects Branch No. 5 Division of Operating Projects U. S. Nuclear Regulatory Commission Washington,, D.C.

20555 Gentlemen:

Subject:

Docket No. 50-206 Additional TMI-2 Related Requirements San Onofre Nuclear Generating Station Unit 1 By letter dated May 7, 1980, you indicated that five additional items have resulted from the various reviews following the TMI-2 accident which are applicable to operating reactors. The five items are as follows:

1. I.A.1.3 - Shift Manning

2. I.A.3.1 - Licensing Examinations

3. I.C.5 -

Licensee Dissemination of Operating Experience

4. II.K.3 - LOFW and Small Break LOCA Generic Review Matters

5. III.D.3.4 -

Control Room Habitability Based on your letter, Items 1, 2, 3, and 5 involve actions for all reactor plants whereas Item 4 involves 28 separate actions concerning only specific light water reactor types. Enclosures (2), (3) and (4) of your letter provided specific information concerning the implementation require ments for Items 3, 4 and 5 while Enclosure (1) summarized the implementation schedules for Items 1, 2, 3, 4, and 5, as they apply to the various operating reactor designs. You requested that we reply within 30 days concerning our commitments to meet the implementation requirements for Items 1, 2, 3, 4, and 5 above.

The purpose of this letter is to advise you that we have completed our review of your May 7, 1980 letter, including the Enclosures thereto.

Submitted herewith are 20 copies of the report entitled, "Commitments Concern ing Five Additional TMI-2 Requirements, San Onofre Nuclear Generating Station Unit 1, June, 1980."

The enclosed report contains our commitments to meet the implementation requirements for Items 1, 2, 3, 4, and 5 above.

8006190 Sys&

D. M. Crutchfield, Chief June 13, 1980 If you have any questions or desire further information concerning the enclosed report, please contact me.

Very truly yours, Enclosures (20)

COMMITMENTS CONCERNING FIVE ADDITIONAL TMI-2 REQUIREMENTS

-San Onofre.-Nuclear..Generating Station Unit 1 June, 1980

1.

I.A.1.3 -

Shift Manning Our commitments concerning this Item cannot be formalized until the issuance of the specific NRC implementation requirements.

As discussed in your May 7, 1980 letter, the NRC implementation requirements for this Item will be provided shortly.

Following receipt and review of the implementation requirements, we will advise you, in a timely manner thereafter, concerning our commitments to meet this Item.

2.

I.A.3.1 - Licensing Examinations By letter dated March 28, 1980, you provided information relating to the revised scope and criteria for licensing examinations.

Based on this information, we have revised our operator training program to assist our operators in successfully passing the revised licensing examinations.

3. I.C.5 - Licensee Dissemination of Operating Experiences The procedure governing feedback of operating experiences to the plant staff will be reviewed and modified, as necessary, to accomplish the objectives -contained-- in -Enclosure, (2)--of-your-.-May 7... 1980...-letter.._ -The review and modifications of the procedures will be completed and the procedures put into effect by January 1, 1981.

4.

II.K.3 - LOFW and Small LOCA Generic Review Matters Based on Enclosures (1) and (3) of your May 7, 1980 letter, 13 of the 28 separate actions included in this Item are identified as being applicable to San Onofre Unit 1;

however, it has been confirmed with the NRC, through the Westinghouse Owners Group, that 3. of these 13, specifically Actions II.K.3.25, "Loss of AC Power on Pump Seals," II.K.3.29, "Perfor mance of Isolation Condensers with Non-Condensibles,"

and II.K.3.44, "Anticipated Transients with Single Failure to Verify No Fuel Failure" are applicable only to boiling water reactor types.

It is our under standing that you will forward a letter shortly to clarify this issue.

Our commitments to meet the implementation requirements for the remaining 10 separate actions which are applicable to San Onofre Unit 1 are discussed below:

II.K.3.1 -

Installation and Testing of Automatic PORV Isolation System As discussed in Enclosure (3) of your May 7, 1980 letter, the implementa tion of this Action has. been deferred until after the studies specified, in Action II.K.3.2. Our commitments to meet the implementation require ments of Action II.K.3.2 are discussed below.

It is expected that the studies will substantiate that an automatic PORV isolation system is not warranted.

Independent of the completion of the studies specified in Action II.K.3.2, it is our position that an automatic PORV isolation system is not warranted. This position is based on the Westinghouse Owners Group analyses of the ultimate heat sink function (i.e., manual operation of the PORV) documented in WCAP-9600, and the decreased intensity of a number of plant transients, given the PORV(s) operation (i.e., operation

-2 of the PORV mitigates the extent of overpressure. Inadvertent failure of the proposed automatic PORV isolation system could impair this function.

In addition, the plant modifications, procedure changes and operator training (i.e.,

NUREG-0578 requirements) provide assurance that the function of the automatic isolation system will be provided by operator actions.

Furthermore, failure to isolate stuck open PORV(s) has been analyzed and results in no core uncovery.

II.K.3.2 -

PWR Vendor Report on PORV Failure Reduction A report on PORV failure reduction will be submitted to the NRC by January 1, 1981.

The report will address the items contained in Enclosure (3) of your May 7, 1980 letter.

It is expected that the report will be submitted through the Westinghouse Owners Group.

II.K.3.3 -

Reporting Safety and Relief Valve Failures and Challenges In accordance with "or Techriical Specifications, failures -of -relief-or safety valves to close require prompt notification to the NRC with a written followup report within two weeks.

Commencing immediately, challenges to the relief or safety valves will be documented in the annual report to the NRC.

II.K.3.5 - Automatic Trip.of Reactor Coolant Pumps.During LOCA In our August 29, 1979 response to IE Bulletin No.79-06C concerning this

subject, we referenced the Westinghouse Owners Group analyses of the affect of reactor coolant pump (RCP) trip during small break LOCA's documented in WCAP-9584. Based on the analyses as applied to San Onofre Unit 1, we concluded that automatic RCP trip coincident with safety injection initiation is appropriate for San Onofre Unit 1 to provide assurance that the peak clad temperatures following all LOCA and non-LOCA transients remain within acceptable limits.

As requested by the Bulle tin, the details of the automatic RCP trip design were provided as part of our August 29, 1979 response.

However, as directed by letter dated October 3, 1979 from the Office of Inspection and Enforcement, Region.V, we have not made the final electrical hookup of the design change pending review and approval by the Office of Nuclear Reactor Regulation.

It is our position that implementation of the automatic RCP trip proposed in our August 29, 1979

response, in conjunction with the procedure changes and operator training implemented as required by NUREG-0578, is adequate to resolve the issue of tripping the RCP's in case of a LOCA, and that alternate solutions are not warranted.

Therefore, we do not plan to evaluate alternate solutions to RCP trips as requested by Enclosure (3) of your May 7, 1980 letter.

As discussed above, we have installed the automatic RCP trip design, except the final electrical hookup. Following review and approval of the design change by the Office of Nuclear Reactor Regulation, we will make the final electrical hookup and place the system in service.

-3 II.K.3.9 - Proportional Integral Derivative (PID) Controller Modifications In accordance with the Westinghouse -

recommended, modification, we will set the derivative time constant in the PID controller for the pressuri zer PORV to off by July 1, 1980.

This modification, in effect, removes the derivative action from the controller which decreases the likelihood of opening the PORV since the actuation signal for the PORV is then no longer sensitive to the rate of change of pressurizer pressure.

II.K.3.10 - Proposed Anticipatory Trip Modifications Since we have not proposed any anticipatory trip modifications, the implementation reqirements contained in Enclosure (3) of your May 7, 1980 letter are not applicable to San Onofre Unit 1.

II.K.3.12 - Confirm Existence of Anticipatory Trips Upon Turbine Trip Sarr Onofre--Unit currently-has-an ant-icipatory-reactor --trip--on. -turbine trip.

Therefore, as indicated in Enclosure (3) of your May 7, 1980 letter, no further actions are required.

II.K.3.17 -

Report on Outages of ECC Systems-Licensee Report and Proposed Technical Specification Changes A report detailing outage dates, lengths of outages and causes of the outages for all ECC Systems covering the past five years will be prepared and submitted to the NRC.

The report will be submitted by January 1, 1981.

II.K.3.30 Revised Small-Break LOCA Methods to Show Compliance with 10 CFR 50, Appendix K The present Westinghouse small break -evaluation model used to analyze San Onofre Unit 1 is in conformance with 10 CFR 50, Appendix K. However, Westinghouse has indicated that they will, nevertheless, address the specific NRC items contained in NUREG-0611 in a model change scheduled for completion by January 1, 1982.

II.K.3.31 Plant Specific Calculations to Show Compliance with 10 CFR 50.46 Since San Onofre Unit 1 has stainless steel cladding versus zircaloy cladding, the licensing basis remains the Emergency Core Cooling System Interim Acceptance Criteria and not 10 CFR 50.46.

The present Westing house small break evaluation model and small break LOCA analyses for San Onofre Unit 1 are in conformance with 10 CFR 50, Appendix K, and the Interim Acceptance Criteria.

As stated in the response to Action II.K.3.30 above, Westinghouse plans to submit a new small break evalua tion model to the NRC for review by January 1, 1982.

If the results of

-4 this new Westinghouse model and subsequent NRC review and approval indicate that the present small break LOCA analyses are not in confor mance with the Interim Acceptance Criteria, a new analysis utilizing the new and approved Westinghouse model will be submitted to the NRC by January 1, 1983 or one year after NRC approval of the new model.

5.

III.D.3.4 -

Control Room Habitability This Item duplicates *the Systematic Evaluation Program (SEP)

Topic VI-8, "Control Room Habitability,"

and at least part of SEP Topic 11-1.3, "Potential Hazards or Changes in Potential Hazards Due to Transportation, Institutional, Industrial and Military Facilities."

It is our under standing from informal discussions with the Regulatory staff that this subject will now be taken out of the SEP.

Based on this understanding, we will perform the necessary evaluations as contained in Enclosure (4) of your May 7, 1980 letter and submit the results of the evaluations to the NRC by January 1, 1981.

As requested by Enclosure (4) of your May 7, 1980 letter, we will initiate preliminary design and engineering efforts required to implement any modifications shown to be necessary.

However, we do not plan to initiate any procurement or construction activities until after the Regulatory staff has reviewed our evaluations and concurs with them.

It is our intention to target the modifications for completion by January 1, 1983.