ML18054B519
| ML18054B519 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/27/1990 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-68578, NUDOCS 9004040023 | |
| Download: ML18054B519 (2) | |
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I consumers Power POW ERi Nii MICHlliAN'S PROliRESS General Offices: 1945 West Parnell Road, Jackson,' Ml 49201 * (517) 788-0550 March 27, 1990 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
ADDITIONAL INFORMATION RELATED TO STATION BLACKOUT RULE 10CFR50.63 (TAC 68578)
Consumers Power Company letter dated April 17, 1989 provided Palisades response to the Station Blackout Rule 10CFR50.63.
That response was based on the application of NUMARC 87-00 "Guidelines and Technical Bases of NUMARC Initiatives Addressing Station Blackout at Light Water Reactors."
Subsequently, in response to NRC Staff concerns regarding licensee implementation of NUMARC 87-00, NUMARC requested that all licensees provide the NRC with additional information regarding proper documentation and consistent implementation of NUMARC 87-00 guidance.
The purpose of this letter is to respond to the NUMARC recommendation.
Consumers Power Company has reviewed Palisades response to the Station Blackout Rule, the clarifications to NUMARC 87-00, and documentation related to the NRC's review of other plant responses to the rule.
Based on this evaluation, we conclude that the information provided in our April 17, 1989 response was based on the proper use of the NUMARC 87-00 guidance, subject to the following clarifications:
- 1. The ac Power Characteristic Design Group identified in our April 1989 letter was Pl based on the anticipated completion of a modification to the Palisades Plant that was designed.to provide an additional source of offsite power to the plant.
Without this additional source of offsite power, Palisades would have been designated as a P2 plant based on the off site power system being in the I3 Group.
- This variation in our use of the NUMARC 87-00 guidance was explained in the first paragraph of Section A of our April 17, 1989 letter.
The modification to incorporate the additional source of off site power been completed and declared operational.
Thus, based on our present offsite power configuration, Palisades is properly classified in Power Characteristic Design Group Pl.
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9004040023 900327 PDR ADOCK 05000255 P
PDC OC0390-001S-NL01 A CM5 ENERGY COMPANY has
~uclear Regulatory Commission Palisades Plant Add'tl Info Station Blackout Rule March 27, 1990
- 2. Severe weather (SW) and extremely severe weather (ESW) categories were determined based on plant-specific meteorological data which differs from the data provided in NUMARC 87-00, Tables 3-2 and 3-3.
Use of plant-specific data resulted in an ESW Group lower than that provided in Table 3-2.
Use of plant-specific data resulted in the same SW Group that would have been calculated using Table 3-3 data.
The resultant ac power charac-teristic group ranking of Pl is not effected by use of the lower ESW classification.
- 3. The statement made in our April 17, 1989 response that control room temp-erature would not exceed 110°F during a four-hour station blackout was based on an analysis using the NUMARC 87-00 methodology given in Section 7.2.4.
That analysis was a misapplication of the NUMARC 87-00 methodology in that the analysis took credit for one non-concrete wall as a heat sink.
We are currently recalculating the transient temperature in the control room following a loss of ventilation.
Based on similar analyses performed by other plants, we are confident the calculation will show that the Palisades control room temperature will remain below 120°F during a station blackout event of four hours duration. A summary of the results of this calculation will be provided to you by June 29, 1990.
- 4. The diesel generator target reliability is 0.95.
We fully understand that this reliability level is to be maintained.
A Diesel Generator Reliability Program is currently being implemented to track and maintain the targeted level of diesel generator reliability. Finalization of all details of the reliability program is awaiting formal resolution of Generic Issue B-56, "Diesel Generator Reliability".
- 5. Documentation of the applicability of NUMARC 87-00 assumptions, analyses, and other related information used in the Palisades coping evaluation is available for review.
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Thomas C Bordine Plant Licensing Administrator CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC0390-001S-NL01 2