ML20101C793
| ML20101C793 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/07/1984 |
| From: | Counsil W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737 A02959, A2959, NUDOCS 8412210198 | |
| Download: ML20101C793 (4) | |
Text
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i December 7,1984 Docket No. 50-423 A02959 Director of Nuclear Reactor Regulation Mr. B. 3. Youngblood, Chief Licensing Branch No.1 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555
References:
(1)
W. G. Counsil letter to B. 3. Youngblood, A02959, dated April 5,1984.
(2)
W. G. Counsil letter to D. G. Eisenhut, A02959, dated November 28,1933.
(3)
B. 3. Youngblood letter to W. G. Counsil, dated November 28, 1984.
Dear Mr. Youngblood:
Millstone Nuclear Power Station, Unit No. 3 Supplement I to NUREG-0737 Safety Parameter Display System In Reference (1), Northeast Nuclear Energy Company (NNECO) submitted the Safety Analysis Report (SAR) for the Millstone Unit 3 Safety Parameter Display
. System (SPDS). This SAR provided information to the NRC Staff demonstrating that our SPDS was being designed to meet the provisions of Supplement I to NUREG-0737.
A meeting was held with the NRC Staff on September 25,1984 to discuss the Millstone Unit 3 SPDS. One of our main objectives of that meeting was to obtain specific NRC Staff comments pertaining to our SPDS plans. Although the NRC Staff's review was not complete at that time and most comments were general in nature, the NRC Staff did conclude that our SPDS was conceptually acceptable.
One topic discussed at the September 25,1984 meeting with the NRC Staff was the implementation schedule for our SPDS. We informed the NRC Staff at that meeting that we were revising our implementation schedule submitted in Reference (2) to reflect a phased implementation approach, and that we would formally submit a revised schedule at a later time. The primary purpose of this submittal is to provide a schedule for our two-phase approach and to delineate those items included in our SAR that will be implemented during each phase.
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, All items included in Phase I will be fully operable (including operator training, procedures, and a users manual) by fuel load and represent a functional SPDS.
The following SPDS features will exist at the completion of Phase I (the page
- where each item appears in our SAR is provided in the parentheses):
o Inadequate core cooling displays (pg.1-3)
Core map of core exit thermocouples (pg.1-3) o o
Pressure / temperature plots (pg.1-4)
Subcooling and superheat displays (pg.1-4) o o
99% design availability (pg. 2-1)
Pre and post event historical data storage (pg. 2-2) o o
Historical data access (printed output only) (pg. 2-2) o Display of critical safety function variables (pg. 3-3) o Critical' safety function status blocks (pg. 4-1)
Critical safety function status trees (pg. 4-1) o o
Sensor signal validation of physically redundant sensors (pg. 5-1) o Verification and validation (pg. 6-1) o Human f actors review of displays and man-machine interf ace (pg. 7-1)
The following features will be implemented during Phase II and will be fully operable (including operator training and revised or new procedures and users manual) prior to start-up from the first refueling outage (the page where each item appears in our SAR is provided in the parentheses):
o Inference of a third channel using analytic redundancy,if necessary (pg.1-3)
Time history plots of inadequate core cooling variables (pg.1-4) o o
Horizontal or vertical bar graphs,if necessary (pg. 2-2) o Mimic /P&ID displays (pg. 2-2) o Multivariable plots vs. time (pg. 2-2) o Variable vs. variable plots (pg. 2-2) o Plant variable information to aid critical safety function assessment and execution of emergency operating procedures,if necessary (pg. 4-2)
This phased implementation approach permits the prompt implementation (i.e.,
by the completion of Phase 1) of a functional SPDS which is sufficient to support f ull power operation.-
We have recently received NRC Staff comments (Reference-(3)) rega'rding our-
-l SPDS SAR. We do not believe that any of the NRC Staff comments affect our.
plans for a phased SPDS implementation. In fact, the nature of the NRC Staff comments'and our belief that all these comments can be adequately resolved during Phase I increases our confidence that we are implementing an SPDS which complies with the provisions of Supplement I to NUREG-0737 and one which the NRC Staff will find acceptable.
Nonetheless, our SPDS efforts have progressed to the point where any significant perturbations to our SPDS design will jeopardize the completion of the Phase I
~
items by fuel load. Therefore, we respectfully request receipt of NRC Staff concurrence with our two-phase approach by January 15, 1985.
We do not
. believe that our response to Reference (3) is necessary for the NRC Staff to -
concur with our two-phase approach.
Receipt of NRC Staff concurrence with our two phase approach by January 15,
-1985 will represent NRC Staff recognition that a functional SPDS sufficient to support full power operation will be fully operable by the completion of Phase I.
It will also represent recognition that any not yet identified NRC Staff concerns which result in significant changes to our SPDS design jeopardize our ability to -
implement Phase I items by fuel load, and that these items may not be implemented until Phase II.
We recognize that comments from the Procedures.& Systems Review Branch (PSRB) may not be included in Reference (3). One item of potential PSRB interest which could involve deferred resolution is in the area of parameter-selection. The parameters chosen for inclusion in our SPDS are solidly based
. upon Revision 1 to the Westinghouse Owners' Group (WOG) Emergency Response Guidelines (ERGS).
Our objective has always -been to maintain complete compatibility between our SPDS and our Emergency Operating Procedures (EOPs), which are similarly based upon the WOG ERGS.
If there are any.
parameters beyond those currently' included in our SPDS design that the NRC Staff believes appropriate for inclusion, the optimum course of action would be to defer the addition of those parameters to our SPDS until the WOG ERGS are revised and subsequent revisions to our EOPs are implemented.
l
- If the NRC Staff has any questions regarding this submittal, we are available to meet with the NRC Staff or to discuss this submittalin more detail.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY et.al.
BY NORTHEAST NUCLEAR ENERGY COMPANY Their Agent h/f f
JW.n. 1;tAvn m y W. G. Counsil' Senior Vice President y
_4 cc:
Mr. G. W. Lapinsky, Jr.
NRC Human Factors Engineering Branch Mr. F. Orr NRC Procedures & Systems Review Branch
.