ML20038D138
| ML20038D138 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 11/16/1981 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TASK-2.K.3.30, TASK-TM TAC-45859, NUDOCS 8112160094 | |
| Download: ML20038D138 (2) | |
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SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, California 95813; (916) 452-3211 November 16, 1981 s
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MR HAROLD R DENTON t
7 DIRECTOR OF NUCLEAR REACTOR REGULATION
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RESPONSE TO OCTOBER 23, 1981 MEETING ON VERIFICATION TESTING FOR SB LOCA METHODS This letter expresses our understanding of the agreements reached in the meeting of October 23, 1981, with you and members of your staff.
In summary, the staff concluded that it.is not clear that further verification testing of our SB LOCA methods is required and agreed to participate in'an in depth review of the current-B&W SB LOCA Methods Program including the verification testing base. This review is to begin as soon as practical and will include the review of results achieved with the improved models and methods now being developed. This review is scheduled for completion in conjunction with the SB LOCA Methods Program by June 1, 1982.
In addition, the staff stated that.a commitment to RCS vents and water level measurement would support their continued confidence in the Babcock 6 Wilcox system.
Based on the above understanding, we are committed to the following:
1.
We will participate in a joint effort with the staff to assure that our current S3 LOCA metnods and ATOG efforts are fully understood.
This program will include the following:
- Code parameters, models, assumptions, etc., which are important in controlling dynamics of interest will be identified and available experimental data substantiating their validity will be reviewed.
This would be done using results of the improved evaluation _model in order that the most accurate-dynamic response characteristics o/
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- Additional experimental data, from separate effects or integral j[
tests, will'be defined which address specific technical gaps, if any.
Our position is not'one of opposition to additional testing.
Instead, we want to assure that questions which must be answered are answered in the most appropriate technical and cost-effective manner.
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- Identify where and how additional experimental data may be obtained, if any is required.
With your cooperation, we commit to complete this program by June 1, 1982.
It is expected that the NRC staff will continue its review and approve the ATOG program by April 1, 1982.
2.
As requested in the meeting, we are providing a summary of Dr. Roy's presentation on the philosophy underlying ATOG. The attached,
" Abnormal Transient Operating Procedures for Nuclear Power Plants", by J. J. Kelly and D. H. Williams, includes the total scope of the ATOG approach as well as the philosophy presented by Dr. Roy.
3.
In order to provide further support to the staff's confidence in the B&W designed systems, we will install RCS vents in the pressurizer and the hot leg on a schedule to be agreed upon with the staff. We will provide schedule information within six months.
We are also commiting to proceed with the design and installation of instrumentation to measure the water level in the reactor coolant system.
It is our intention to work closely with the staff to develop a schedule and select a design which will provide the operator with valid and unconfusing data.
4.
In response to Dr. Mattson's question, information on the formation of steam during normal operating transients including rapid cooldown is being addressed in our response to Generic Letter 81-21.
We believe this letter reflects the major conclusions and agreements reached in the October 23 meeting.
The B&W Owners Group is prepared to begin the review of our SB LOCA Methods Program with the staff and request that the assigned staff reviewer contact Mr. Lou Lanese of GPUNC to establish the details for carrying out this review.
It is our intent to implement this review without impacting the current schedule for the completion of the SB LOCA Methods Progran.
)M John. Mattimoe Assistant General Manager and Chief Engineer l
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