ML20043E819
| ML20043E819 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 06/06/1990 |
| From: | Keuter D SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| AGM-NUC-90-163, NUDOCS 9006130421 | |
| Download: ML20043E819 (3) | |
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SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street. P.O. Itox 15830. Sacramento CA 96R521830. (916) 452 3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA AGM/NUC 90-163 June 6, 1990 1
i U. S. Nuclear Regulatory Comission Attn: Document Control Desk Hashington, DC 20555 i
Docket No. 50-312 L
Rancho Seco Nuclear Generating Station License No. DPR-54 USE OF DIESEL GENERATOR SETS AS PEAKING POWER SUPPLIES
Reference:
D. Keuter (SMUD) to J. Larkins (NRC), AGM/NUC 90-067 dated May 10, 1990 Attention:
John Larkins In the referenced letter, the District requested temporary exemption from the interpretation of General Design Criteria (GDC) 17. " Electric Power Systems",
as stated in Branch Technical Position ICSP-8 (PSB), referenced in Standard Review Plan Section 8.3.1, "A-C Power Systems (Onsite)".
Based on further discussions with NRC staff, we understand that a formal exemption is not required and therefore withdraw the May 10, 1990 request.
To keep you apprised of our plans regarding diesel generator operation, the District provides the following information.
As briefly discussed in the reference, the District has a vital need to provide additional peaking capacity on its electrical distribution system.
This need is especially critical during the hot summer months in the
. Sacramento service area when afternoon air conditioning usage places heavy demands on the system. Having the three emergency diesel generators available to supply approximately 9.3 megawatts for 3 to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> per day during these high demand periods will benefit the District and its ratepayers economically as well as enhancing system reliability.
i 9006130421 900606,
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ADOCK 0500 g DR
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RANCHO SECO NUCLEAR GENERATING STATION D 14440 Twin Cities Road, Herald, CA 95638 9799;(209) 333 2935 j
1 i
Mr. Larkins AGM/NUC 90-163 l
Engineering is performing a detailed review of the Preventive Maintenance (PM)
Program to identify PM tasks necessary to maintain the units and their auxiliaries in good fonctional condition and to enhance reliability for daily peaking service. The District will structure its diesel generator maintenance program such that the units can be returned to nuclear service following appropriate Technical Specification related maintenance and testing. Rancho Seco administrative controls on this equipment will remain in force.
In preparation for operating the diesel generators as peaking units, the District is also evaluating the following:
Nuclear service bus voltage protection schemes; Interaction between the "A" and "A2" nuclear service buses; Diesel generator response on loss of offsite power while synchronized to the grid; and Use of the 69KV transformer as the output transformer for the "B"
TDI diesel generator.
The above evaluations will determinc
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If there is any imptet on the "A" Bruce-GM diesel generator which is reserved for use *s a backup power supply.
If there is adequate protection for the diesel generators in the event of a lc,s of offsite power while synchronized to the grid.
What operator actions are required in the event of system low voltage or loss of offsite power with one or more of the diesel generators synchronized to the grid.
The preliminary plan is to run the "B" Bruce-GM diesel generator through Startup Transformer #2, the "A" TDI diesel generator through Startup Transformer #1 and the "B" TDI diesel generator through the 69KV transformer, which is connected to the local offsite distribution system.
The District will not fast start the diesel generators nor automatically load the units via the nuclear service bus auto load sequencing scheme.
Also, the plan limits the diesel generators to their nuclear service ratings of 2750KH for the "B" Bruce-GM and 3300KH for each of the two TDIs.
Maintenance and Operations will perform an operational readiness program on each diesel generator during the month of June to ensure that the units are in l
good functional condition and ready for use as peaking units.
The operational l
l readiness program requires both preventive and corrective maintenance based on a review of existing work requests and on input from maintenance personnel and l
the system engineer.
Included in this program will be a simultaneous test run l
of all three diesel generators to verify acceptability of equipment and l
procedures for power production usage.
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i
c.
i4r. Larkins AGM/NUC 90-163 The District will revise operating procedures to provide procedural direction for synchronizing / removing the three diesel generators to/from the grid.
Also, Operations will revise the appropriate Casualty Procedure (s) for a loss of offsite power event with one or more Units synchronized to the grid.
Engineering will document implementation of this program via TSAP-4124, System Layup Program.
Since the previous submittal (referenced) the District has determined that a layup modification will be required if a decision is made to use the 69KV transformer as the output transformer for the "B" TDI diesel t
generator. This configuration was used for startup testing of each of the TDI diesel generators.
The modification involves disconnecting the diesel generator output breaker from its associated nuclear service bus and connecting it to the low voltage terminals of the 69KV transformer.
The contemplated modifications will include temporary generator protection and synchronizing circuits.
Members of your staff with questions requiring additional information or
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clarification may contact Steve Rutter at (209) 333-2935, extension 4911.
I Sincerely,
~
' ' v-ee %
,e Dan R. Keuter Assistant General Manager Nuclear cc:
J. B. Martin, NRC, Halnut Creek C. Myers, NRC, Rancho Seco l