ML19257C270
| ML19257C270 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 01/17/1980 |
| From: | Counsil W NORTHEAST UTILITIES |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19257C271 | List: |
| References | |
| TASK-03-06, TASK-3-6, TASK-RR NUDOCS 8001250466 | |
| Download: ML19257C270 (3) | |
Text
'
NORTHEAST UTILITIES
[
1
'm T
ONNECTICUT 06101 k
L iJ
'".',"/' A', O',0 74C January 17, 1980 Docket No. 50-213 Director of Nuclear Reactor Regulation Attn: Mr D. L. Ziemann, Chief Operating Reactors Branch #2 U. S. Nuclear Regulatory C%nission Washington, D. C.
20555
Reference:
(1) Summary of Meeting Held on August 29, 1979, J. J. Shea to CYAPCO, dated September 26, 1979.
Gentlemen:
Haddam Neck Plant Systematic Evaluation Program Seismic Reevaluation During a meeting held in CYAPCO offices on August 29, 1979, Connecticut Yankee Atomic Power Company (CYAPCO) representatives made a brief presentation regarding the status of the Seismic Reevaluation Program for the Haddam Neck Plant. At the end of the meeting, the Staff requested additional details concerning the program. As documented in Reference (1), it was originally CYAPCO's intention to provide a criteria document to the NRC Staff during November, 1979.
This effort had been delayed, primarily because of the urgency associated with implementation of the TMI-related improvements and in complications associated with the development of site-specific spectra.
In response to the Staff request, the following information is hereby provided.
The CYAPCO proposed program is comprised of five distinct parts.
(1) Geology / Seismology In response to the questions raised by the NRC Staff, CYAPC0 has already begun an extensive research effort, with regard to the regional and site-specific geology / seismology. This effort is directed at reevaluating the geological basis which served as input in the original seismic design of the Haddam Neck Plant, in light of more recent geological information currently being discussed among the scientific community.
Ef809 077.
p 8001230 % g
a
. (2) Site-Specific Spectra Discussions with the Staff will continue in an effort to develop a mutually acceptable approach.
This section will be addressed in a supplement to this submittal.
(3) Containment Model CYAPCO proposes to analyze the seismic response and evoluate the structural capability of the containment structure at the Haddam Neck Plant for the effects of the safe-shutdown earthquake.
Floor response spectra will also be generated for use in Part (4) below.
(4) Reactor Coolant System (RCS) Model CYAPCO is proposing to analyze and evaluate the structural response of the RCS piping, RCS components, and the supports of RCS components (i.e., reactor vessel, steam generator, reactor coolant pump, pressurizer) for effects of the design basis earthquake.
(5) Other Structures CYAPCO proposes to analyze and evaluate other structures which house equipment necessary to effect a safe-shutdown (screenwell, primary auxiliary building, control room, auxiliary feedwater pump room) following a seismic event and coincident loss of offsite power.
Floor level response spectra will be generated at appropriate locations within the structures.
The efforts described above will result in an assessment of the integrity of the reactor coolant pressure boundary (RCPB) and in the generation of information necessary to assure the ability to effect a safe shutdown -- the documented objectives of the SEP seismic evaluation.
CYAPC0 and our consultants have expended considerable effort aimed at accomplish-ment of the objectives laid out in that meeting.
Significant effort has been expended in reevaluating the seismic hazard at the Haddam Neck Plant, data gathering, modeling of important plant structures, and modeling of the reactor coolant system.
Site visits have been made by our consultants to verify and supplement information on CYAPC0 drawings, specifications, etc.
Simplistic, preliminary calculations have been performed by our consultants on some structures to enable them to determine appropriate methods for final analyses, and reduce the time span required for those analyses.
It is currently envisioned that development of mutually acceptable site-specific response spectra will govern the timetable for completion of this program.
Portions of the CYAPCO program are provided in Attachment 1, Seismic Reevaluation Program, Criteria Document.
The attached material should be viewed as a draf t, which will be finalized concurrent with the development of site-specific.
1809 078
. epectra and resolution of other technical aspects of the program not addressed in the attached draf t.
The sections attached address criteria for reassessment of the structural adequacy of safety-related structures and the reactor coolant system piping and components under SSE loads. The remaining sections are in various stages of development and will be provided as soon as they are available.
Consistent with statements made by senior management within the NRC Staff, since this program will involve a considerable amount of resources from each of our organizations, it is CYAPCO's intention to obtain the concurrence of the NRC Staff regarding this program, prior to its execution.
Exempted from this statement would be those aspects of the effort, such as RCS modeling, which would not be significantly impacted by future negotiations on this subject.
We trust you find the above information response to your request.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY s
v/
W. G. Counsil
~
Vice President Attachment t
I809'079