ML18348A330
| ML18348A330 | |
| Person / Time | |
|---|---|
| Site: | Palisades  (DPR-020) |
| Issue date: | 07/09/1975 |
| From: | Sewell R Consumers Power Co |
| To: | Purple R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML18348A330 (3) | |
Text
July 9, 1975 DOCKET 50-255,.LICENSE DPR.... 20 PALISADES PLANT, ECCS ANALYSES consumers Power company On December 27, 1974, the Directorate of Licensing, USAEC, issued an "Order for Modification of License" requiring Consumers Power Company to sl.(l:lmi t a reevaluation of ECCS cooling performance for the Palisades Plant.by July 9, 1975.
This "Order" followed a Directorate of Licensing review of *eviiluations of ECCS cooling performance calculated in accordance with an evaluation model developed by Combustion Engineering, Inc, which was submitted on October 21 and December 16, 1974.
The enclosure entitled "Palisades.Core I Reanalysis ECCS Performance ~esults" has been prepared by our NSSS vendor concerning the Emergency Core Cooling System ( ECCS) at the Palisades Plant.
As previously discussed in our lett.er (R. B. Sewell to R. A. Purple dated June 16, 1975), the enclosed analyses used containment data which cont~ins discrepancies.* These discrepancies cause the statement in Section II.C of the enclosure, relative to conservation of the containment parameter, to be incorrect.
Since observing this 'discrepancy, we have conducted a containment pressure evaluation based on Branch Technical Position CSB 6-1.
This evaluation, using one break, showed that the peak clad temperature remained the same.
Based on these results (which are being trans-mitted by the NSSS vendor under separate cover as, Supplement 1 to the ",Palisades Core I Reanalysis ECCS Performance Results"), we have concluded that subsequent analysis using revised.containment data is not required.
We expect to receive the revised containment data from our Architect-Engineer near the end of July and will forward this data for your review.
We will also review this data and provide a revised ECCS analysj_s if it appears that the conclusion that the present analysis is appropriately conservative is not correct.
Yoi.ir letter dated June 13, 1975 requested information (some of which had been
~reviously identifred) to supplement the ECCS reanalysis.
The information requested and our response are listed below.
- 1. Ereak Spectrum and Partial Loop Operations With the possible exception of the discrepancy in the containment data, dis-cussed above, we believe these requirements are met with the enclosed report and 7364
2 conclude that the Palisades Plant conforms to the NRC Final.Acceptance Criteria when evaluated using Combustion Engineering approved methods.
- 2.
Potential Boron Precipitation Our letter (R. B. Sewell to R. A. Purple) dated June 27, 1975 described the current status of this item.
- 3.
Sing1e Failure Analyses A review of Palisades Plant ECCS equipment for vulnerab.ili ty to single failures as described in the Nuclear Regulatory Commission's Standard Review Plan Branch Technical Position EICSB-18 was conducted. *This Technical Position required identification of valves which, if the postu..:.
lated single system failure caused their maloperation, could cause loss of safety function.
The following five valves were identified as having the capability of reduc-ing ECCS performance if any one were to shut from the normally open position because of a single failure or operator error:
M0-3041, -3045, -3049 and -3052, Safety Injection Tank Isolation Valves CV-.3006, Shutdo'wn Cooling Flow Control Valve To comply with EICSB-18, the above valves will have their electrical power removed from the operator when in the open position.
The remaining valves and components in the system satisfy the single operator error or single failure criteria through redundancy.
- 4.
Submerged Valves The request for review of specific equipment which may become submerged following a LOCA was received on June 18, 1975.
As of this date, we do not have a completion time set for this review.
We will inform you as soon as the review is completed.
- 5.
Containment Pressure A containment pressure evaluation based on Branch Technical Position CSB 6-1 has been conducted and is being transmitted separately by our NSSS vendor as Supplement 1. to the "Palisades.Core I Reanalysis ECCS Performance Results."
The December 27, 1974 "Order for Modification of License" also required that a proposed Technical Specifications change accompany the ECCS reevaluation..
Accordingly, we have enclosed a proposed Technical Specifications change which both deletes our present Appendix B (interim special Technical Specifications) and incorporates appropriate changes into Appendix A.
We will continue to
3 follow the more r,estrictive aspects of this proposed Technical Specifications change and,the existing Technical Specifications until approval of this change is received.
Neither the PRC orSARB have had an opportunity to review this proposed Technical Specifications change.
These reviews are scheduled for comple-t~on by mid Aiigust 1975.
- The results of these reviews will be reported at that time.
Ralph B. Sewell Nuclear Licensing Administrator CC:
JGKeppler, USNRC