ML20155A937
| ML20155A937 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 09/30/1988 |
| From: | Papanic G YANKEE ATOMIC ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-03-06, TASK-3-6, TASK-A-46, TASK-OR, TASK-RR FYR-88-135, GL-87-02, GL-87-2, NUDOCS 8810060123 | |
| Download: ML20155A937 (5) | |
Text
.
T:lephone (61T) 872-8100 n?X 710 390-7:t9 YANKEE ATOMIC ELECTMC COMPANY y
1671 Worcester Road, Framingham, Massachusetts 01701 September 30, 1988 FYR 88-135 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Attention:
Mr. Morton B. Fairtile, Project Manager Project Directorate I-3 Division of Reactor Projects I/II
References:
(a) License No. DPR-3 (Docket No. 50-29)
(b) Letter, NYR 88-184, USNRC to Seismic Qua ification Utility Group (SQUG), dated July 29, 1988 (c) Letter, NYR 87-45. USNRC to YAEC, Generic Letter 87-02, "Verification of Seismic Adequacy of Hochanical and Electrical Equipment in Operating Reactors. Unresolved Safety Issue (USI) A-46." dated February 19, 1987 sd) Letter, NYR 87-142, "NUREG-0825 Section 4.11, Seismic Design Considerations," dated July 16, 1987 (e) Letter, FYR 88-83, YAEC to USNRC, "SEP Topic III-6:
Seismic Evaluation Reports " cated September 2, 1983 (f) Lettor, N. P. Smith, SQUG Chairman, to L. C. Shao, Director of USNRC, dated September 22, 1988
Subject:
Response to NRC Generic SER on Proposed SQUG Resolution for Unresolved Safety Issuo A-46
Dear Sir:
On July 29, 1988, the NRC staff issued via Reference (b), a generic Safety Evaluation Report (SER) on Revision 0 of the Generic Implementation Procedure (GIP) for seismic verification of nuclear plant equipment. This procedure was developed by the Seismic Qualification Utility Group (SQUG) as a means for resolving USI A-46.
Yankee Atomic Electric Company (YAEC) is a participating member of the SQUG.
This letter responds to the NRC request for our plent-specific seismic verification plans and schedule for Yankee Nuclear Power Station (YNPS),
cor detent with the requirements of beneric Letter 87-02, Reference (c).
i f
United Stetse Nuclose Rsguletory Commission Ssptembsr 30, 1988 i
Attention:
Mr. Morton B. Fairtile Pago 2 FYR 88-135 The NRC generic SER endorses the methodology and criteria embodied in Revision 0 of the GIP, subject to satisfactory resolutton of a number of open issues and NRC comments.
Since both the final GIP and NRC review are presently incomplete, our plans for implementation of the GIP are necessarily preliminary.
It is YAEC's current plan to address USI A-46 by use of the generic criteria and methodology in Revision 0 of the GIP, as clarified by the SQUG responsed to the NRC SER in the SQUG 1etter to Mr. L. Shao, Reference (f).
Assuming no major changes in the work scope currently envisioned, as described in Revision 0 of the GIP, including the criteria to l
be added for electrical raceways, tanks, heat exchangers, and relays, YAEC plans to perform the seismic verification plant walkdown by the conclusion of the second refueling outage after receipt of the final SER supplement L
resolving all open issues.
If the final NRC SER supplement is issued, with no open items, by the second quarter of 1989, then our plant walkdown is expected i
to commence by the second quarter of 1996, and would be completed during the j
l 1991 refueling outage. Training of our walkdown team members will be accomplished prior to the plant walkdown when the SQUG training program is available and endorsed by tho NRC.
l YAEC's implementation plan and schedule, as described above, are based on the "SQUG Commitments" identified in each section of the GIP, with the clara!1 cations of those specified commitments delineated in Enclosure 1 to this letter. The clarifications described in Enclosure 1 are considered t
applicable for our facility for the reasons given therein.
The guidance methodology contained in each section of the GIP will be followed to the extent that it is deemed practical.
The implementation of the YAEC program plan to comply with the requirements cf Reference (c) and SQUG GIP is based on NRC acceptance of the l
program plan described above including the clarifications listed in l.
In addition, our implementation and schedule commitment is contingent upon our current understanding of the GIP.
If the scope of the final version of the GIP, or the cost and ef fort required to implement it at our f acility, change significantly f rom the current scope and cost estimates. YAEC will re-evaluate its commitments.
YAEC also reserves the right to review the final version of the GIP and to take exceptions before performing the seismic verification walkdown.
The seismic adequacy of a large percentage of equipnent within the YNPS seismic scope as defined in Enclosure 1 has been reviewed by the staff during the Systematic Evaluation Program (SEP).
That review is documented in the SEP Topic III-6 SER, which is presented in Reference (d).
Electrical raceways and certain mechanical and electrical equipment were deleted from the scope of the SEP review by mutual agraement between YAEC and NRC with the understanding that they would be evaluated during the resolution of USI A-46.
All other components within the seismic scope which have been found acceptable under SEP Topic III-6 will not be requalified under USI A-46.
~
=-
1 tinited States Nuc1ccr R:suictory Ccasaissien Septecher 30, 1988 Attention:
Mr. Morton B. Fairtile Page 3 FYR 88-135 We will advise you in writing of any changes in our implementation plans and schedules.
If you have any questions, please contact us.
+.
Very truly yours.
YANKEE ATOMIC ELECTRIC COMPANY hu a
-un C. Papa Jr.
/
Senior Project Engineer Licensing f
CP/15.1050 Enclosure cc USNRC Region I
[
USNRC Resident Inspector (YNPS) i i
l l
l l
l l
f ENCLOSURE 1 Pcgo 1 of 2 glarifications to c q i
t 70U0 Connitment f
GIP Section 3.1.2.3.
States that "If achieving and maintaining safe shutdown is dependent on a singio item of equipment whose failuro, either due to seismic loads or random failure, would prevent accomplishment of any of the four essential safe shutdown functions, an alternative path to safe shutdown by use of a different train or a different item of equipment in the same train will be identified for seismic evaluation which is not dependent on that item l
of equipment."
l Yankee Clarification j
The Yankee Nuclear Power St.ation (YNPS) is one of the plants iv. the NRC's
[
Syotematic Evaluation Program (SEP).
A seismic evaluation of the YNPS was conducted in the SEP. The staff's Safety Evaluation Report (SER) on the setemic issue for the YNPS is contained in Reference (d).
One of the most i
important issues during SEP was to establish the seismic scope for the YNPS.
The NRC and Yankee have accepted the following seismic scope for the YNPS:
1.
Those systems and components necessary to ensure the integrity of the Reactor Coolant Pressure Boundary (RCPB).
i 2.
Those systems and components necessary to ensure the integrity of the Secondary System Pressure Boundary (SSPB).
j f
3.
A dedicated Safe Shutdown System (SSS) to provide a means of decay heat romoval.
l 4.
Electrical equipment needed for the operation of these systems, j
l 5.
Those structures (including masonry walls) that house the above equipment or whose failure could affect the operation of these systems.
The systems and components in this seismic scope provide a single train i
capability. The system boundary of the RCPB and SSPB generally extends out to the first normally closed valve, or to the first nomally opon valve that is l
capable of remote closure. For these valves, the electrical components j
necessary for their closure are included within the scope.
The following justification is provided for the single train concept in the staff's SER:
"The systems and components in the seismic scope provide a single train capability and thus the system function could be disabled by a postulated single failure. However, this system is being provided in the event all other plant systems and equipment are disabled by the earthquake.
Considering the inherent seismic resistance of the plant, and the size and location of the plant, the staff concludes that the degree of redundancy afforded is acceptable."
ENCLOSURE 1 Pcto 2 of 2 Clarifications to CIP (Continued)
The acceptability of a single train dedicated system is based on the inherent seismic resistance of the other plant systems and equipment. This reasoning was reinforced by an evaluation done by EQE, Inc. on the installed plant systems and equipment that would be used along with the SSS.
The results of this evaluation were forwarded to the NRC by Reference (e).
This review used the equipment comparison techniques that are the basis of the GIP, and have essentially shown that the YNPS systems and equipment are capable of withstanding the required seismic motions, i.e., the inherent seismic resistance of the YNPS.
This same clarification was made in Part I of the GI9 in response to Generic Letter 87-02 (Reference (c)), and agreed to by the staff in their generic SER (Reference (b)).
p0UG Commitment GIP, Revision 0. Section 4.1.4 States that "The licansee will verify the anchorage adequacy of safe shutdown equipment by co..parison with seismic demand and a visual inspection of specific anchorage, including its foundation connection, for proper installation." The GIP states that "Visual inspection will be carried out for all required anchorages of identified safe shutdown equipment unless justified by the licensee based on radiation dose concerns or other factors."
yankee Clarification YAEC has performed walkdown inspections of safe shutdown equipment at YNPS during the SEP (see Reference (d)). Those inspections and the subsequent anchorage upgrades are permanent plant records.
YAEC intends to use previous seismic anchorage walkdown results and subsequent engineering design changes for specific SSS equipment to verify their anchorage adequacy as required in CIP Section 4.1.4