ML19250A565
| ML19250A565 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 10/05/1979 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Justin Fuller PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 7910230705 | |
| Download: ML19250A565 (5) | |
Text
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UNITED STATES y y,,,,,
NUCLEAR REGULATORY COMMISSION
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October 5, 1979 Docket No. 50-267 fir. J. K. Fuller, Vice President Public Service Company of Colorado P. O. Box 840 Denver, Colorado 80201
Dear fir. Fuller:
SUBJECT:
PROPOSED PLAN OF If4 SERVICE INSPECTION AND TESTING FOR FORT ST. VRAIN In your letter of August 28, 1979 to Mr. Gammill, you requested NRC's concurrence with your proposed plan for inservice inspection and testing '.ihich you presented at a meeting on August 20, 1979 and later transmitted with the August 28, 1979 letter.
We have reviewed your proposal and offer conments and remarks in Enclo-sure 1.
We trust these comments and remarks are sufficiently clarifying that you can proceed to develop the Fort St. Vrain inservice inspection and testing program as scheduled.
Please do not hesitate to contact us if you need further guidance at this time.
teven A. Varga, A( }n'g Assistant Di rector
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for Light Water R0 ctors Division of Project Management
Enclosure:
Comments and Remarks cc:
Bryant O' Donnell, Esq.
Kelly, Stansfield & 0'Donnell 990 Public Service Company Building Denver, Colorado 80201 James B. Graham Manager, Licensing and Regulation East Coast Office General Atomic Company 2021 K. Street, fl.W.
1203 054 Suite 709 Washington, D. C.
20006 0
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2 0
Comments and Remarks Proposed Plan of Inservice Inspection and Testing for Fort St. rair 1.
We find accentable your proposed plan to dccument your inservice inspection and testing program by modifications and additions to the surveillance sec-tion of the Technical Specifications.
In using this mechanism, we desire that you take the opportunity to propose individual requirements as they are developed rather than assemble a completed package of the entire program for our review.
In this way, you can formally address first the priority topics identified in our letter of January 15, 1979 and discussed in later meetings (i.e., PCRV relief and isolation valves, loop isolation valves, steam gener-ators, PCRV monitoring, PCP.V closures and penetrations, and features to prevent control rod ejection).
2.
In our review of your forthccming proposed Technical Specifications, we plan to use as a guide the proposed ASP: Code,Section XI, Division 2.
!n order to aid us in our review and to expedite its progress, we ask that you include in the basis of each surveillance requirement you propose the identification of the related Subsection and Article of the ASME Code.
Where the requi re-ments of the proposed Technical Specifications and Code differ in substance, an explanaticq and justification should be provided.
We also advise that reference to the Code (aither Divisions 1 or 2) may be made as a means for providing details for our review of such items as inspecticn and testing procedures, acceptance criteria, recordkeeping, and reporting.
3.
We notice that your stated philosophy, "... recognizes generic differences between light water cooled reactors and the Fort St. Vrain high tamDerature 1203 055
-2 gas cooled reactcr, particularly, those differences viich provide an inher-ently superior level of safety." While we, of course, consider in our reviews the many design differences of the HTGR and the inherently slower responses to transients, we are not able at this tire to provide specific credits for these distinctions with regard to a inservice inspection and testing program.
Generally speaking, Fort St. '. ain must have an inservice insp?ction and testing program which fully meets the objectives of those for light water reactors.
4.
Your proposed program places a higher catr aory of classificaticn systems pertaining to the mitigation of Design Basis Accident t;o.1, the sustained loss of forced circulation.
While th is a demanding case in terms of the performance of reactor safety systems, it does not follow that this accident should necessarily be the only case which should receive emphasis in terms of a potential release of radioactivity to it ? environs.
Thus, surveillance for insuring protection against other design basis accidents and minimizing the occurrence for all types cf potential accidents that could result in significant radioactive releases should be equally rigorous.
We also note that DBA No.1 ir.volves a sequence of events that have not been explored by testing and experiment to tne extent that total conficance can be placed on a fully satisfactory performance of all the systems and structures involve 0.
Thus, it is necessary and in accord with the " defense-in-depth" pnilosopny that your inservice inspection and testing program adoress equally the pre-vention of the occurrence of DBA f;o.1 as well as its mitigation.
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, 5.
We notice that your proposed general surveillance requirements v.cuid linit surveillance inspections to visual examinations, observations, and measure-ments and that non-destructive test methods would be used on pressure boundaries only for investigative purposes.
For selected accessible loca-tions of the pressure boundary, it would appear that non-destructive methods should be considered. Also, it is foreseeable that advances in ::DT techniques might eventually make possible Surface and volumetric surveillance of the steam generators and some other hard-to-get-to locations.
Thus, it appears that PSC is exempting itself from applying fiDT techniques where they would be desirable for surveillance and from NDT advances should they occur.
- Rather, you should commit to utilize NDT techniques for surveillance where ren ;onable and to use advances in the technology if such advances would make additional NDT inspections realistically feasible.
You should also make a study of the current state-of-the-art of NDT technology and justify that your reasons for certain exclusions of NDT surveillance are based on lack of equicment avai labi li ty.
6.
In our discussion during the meeting of August 20, 1979, it was ncted that the isolation valves for the PCRV pressure relief system were manually actuated.
In order to meet the objectives of General resign Criteria pertaining to ccn-tainment isolation and in keeping with the purpose and functioning of the PCRV pressure relief system, we believe that these valves should be motor operated with capability for manual actuatien from the control rocm.
The surveillance program proposed for these valves should be equivalent to that for Category A valves as defined in Article 1GV in the croposed ASME Code.
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-4 7.
You proposed that the Office of Inspection and Enforcement serve in.'? ace of a qualified ASME inspection agency as no safety-related systems were built to the ASME Code,Section III. We are taking this proposal under consideration and will advise you later in this matter.
8.
At the August 20, 1979 meeting and in your August 28, 1979 progress report, you deferred discussion of an inservice inspection plan for structural graph-ites.
You should plan to address this topic in the near future.
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