ML20205L261
| ML20205L261 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/25/1988 |
| From: | Dewitt R SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Knighton G NRC, NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20205L264 | List: |
| References | |
| AGM-NPP-88-556, NUDOCS 8811010553 | |
| Download: ML20205L261 (8) | |
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SACRAMENTO P sVNICIPAL UTILITY DISTRICT O P. O. Box 1583o, Sacramento CA 95852-183o,(916) 452-3211 AN ELECTRIC FYSTEM SERVING THE HEART OF CALIFORNIA AGH/NPP 88-556 00T 2 51983 U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Hashington, DC 20555 Docket No. 50-312 Rancho Seco Nuclear Generating Station License No. DPR-54 PROPOSED AMENDHENT NO. 173 Attention: George Knighton In accordance with 10 CFR 50.90, the Sacramento Municipal Utility District proposes to amend Operating License DPR-54 for Rancho Seco and theretore submits Proposed Amendment No. 173.
Proposed Amendment No.173 modifies Technical Specification 3.14 to remove Technical Specification requirements for fire suppression systems in fire zones 75-80.
The zones affected do not require automatic suppression systems.
This change provides an operational enhancement by removing the C0 systems in the noted zones.
Attachment I contains the Safety Analysis Report and the No Significant Hazards Consideration for the changes made by Proposed Amendment No. 173.
Attachment II contains the Technical Specification page affected by Proposed Amendmen: No. 173.
Pursuant to 10 CFR 50.91(b)(1), the Radiological Health Branch of the California State Department of Health Services has been Informed of Proposed Amendment No. 173 by mailed copy of this submittal.
Enclosed is a check in the amount of $150.00, as required by 10 CFR 170.21, "Schedule of Fees."
8311C10553 EG1025,
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AliOCK OSOO g DR RANCHO SECO NUCLEAR GENERATING STATION D 1444o Twin Cities Road, Herald, CA 95638 9799;(209) 333 2935
George Knighton AGM/NPP 88-556 Members of your staff with questions requiring additional information or clarification may contact Ms. Ellen Banaghan at (916) 452-3211, extension 4917.
State of California.
SS County of Sacramento Russell B. DeWitt, being first duly sworn, deposes and says:
that he is Acting Assistant General Manager, Nuclear Power Production of Sacramento Municipal Utility District (SMUD), the licensee herein; that he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information, and belief, and that he is authorized to execute this document on behalf of said licensee, n tu1/
4/ Ally Russell'B. DeWitt Acting Assistant General Manager Nuclear Power Production Subscribedandaffirmedtobeforemeonthis#8 day of
-dLO, 1988.
OFi4CNN L ESTHER H. HUGHES C-v'f/ou M. M(9/
Noi 50 Esther H. Hughes c '
u c-tenoc; 21,1989 Notary Public r
i Attachments cc w/atch:
A. D'Angelo. NRC, Rancho Seco J. B. Martin, NRC, Halnut Creek J. S. McGurk, State of California INPO MIPC (2) t
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ATTACHMENT I Safety Analysis Report and No Significant Hazards Consideration i
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. Safety Analysis Report Log No. 1081 Proposed Amendment No. 173 Page 1 of 4 SAFETY ANALYSIS REPORT Qgitriotion of Chanae fire suppression zones 75, Proposed Amendment No. 173 (PA 173) removes CO2 76, 77, 78, 79 and 80 from lable 3.14-3.
This change removes CO fire suppression systems from those Nuclear Service Electrical Building (NSEB) zones required to be operable by Technical Specification (TS) 3.14.4.
Reason for Chance This change will provide a,i operational enhancement by allowing permanent disabling of the C0 fire suppression system for the switchgear, electrical equipment and battery rooms in the NSEB.
It has been demonstrated that the system designs for these areas do not meet the requirements of 10 CFR 50, Appendix R, Section III.G because actuations of the CO systems 2
could impair the operation of the normal and essential NSEB HVAC Systems.
In addition, based on equipment layout and low combustible loadings, the areas affected do not require C0 systems.
The change will also improve personnel safety by eliminating the potential for personnel exposure to C0 from a discharge within the NSEB.
Evaluation and Basis for Safety Findinas a) Systems, Subsystems, Components Affected PA 173 affects the NSEB fire protection system.
The change will allow permanent disabling of it.e CO, fire suppression systems associated with zons 75 through 80. This will allow hardware changes to be made to prevent simultaneous disruption of both NSEB HVAC trains as a result of a fire.
These systems have been temporarily disabled to prevent this occurrence.
The fire suppression system is described in Section 9.9 of the USAR and TS Sections 3.14 and 4.18.
Fire areas 75.1 through 80 (which correspond to fire zones 75 through 80) are described in the Updated Fire Hazards Analysis Report (UFHAR).
b) Safety function of Affected Systems / Components The fire zones affected are located within the NSEB.
The NSEB is a reinforced concrete structure which houses equipment and support systems for the A2 and B2 essential distribution systems.
Equipment and cabling for the A2 Train and the B2 Train are located on opposite sides of the NSEB and are separated by an eight foot corridor with three-hour rated fire walls on each side.
The safety function of the fire suppression system is to ensure that adequate fire suppression capability is available to confine and extinguish fires occurring where safety-related equipment or redundant systems required for safe shutdown is located.
Safety Analysis Report Log No. 1081 Proposed Amendment No. 173 Page 2 of 4 Eft cts on Safety Functioni The adequacy of the fire suppression capability within the the NSEB is not affected by this change.
The fire loading in each of the areas is low.
The equivalent fire severity in each area is approximately 20 minutes. The loading consists primarily of fire retardant cable and battery casing plastic.
l system to significantly reduce damage to The value of a fixed CO,f fire is limited by the difficulty and time necessary equipment in the event o to achieve the high CO, concentrations required for fire control. Smoke and thermal detectors are installed in each area to provide early warning alarm in the Control Room for prompt fire brigade response and manual fire fighting.
Analysis of Effects on Safety Functions.
The design criteria for fire suppression systems are listed in NEPH 5101.8.
The applicable regulatory standards and guidelines which deal with the need for fixed fire suppression s', stems in rooms of this type are:
10 CFR 50, Ap m dix A, deneral Design Criterion 3 - Fire Protection.
NELPIA, 03 sis Fire Protection for Nuclear Power Plants, March 1970.
ANI Fire /All-Risk Guidelines, 1976.
NUREG 75/087, Standard Review Plan, Section 9.5-1, Fire Protection Systems, NUREG 0800, Standard Review Plan, Section 9.5.1, Fire Protection Program.
a Reg. Guide 1.120, Fire Protection Guidelines for Nuclear Power Plants.
3 None of the design criteria require the installation of CO, suppression systems in the subject areas.
The fire hazards analysis was performed by postulating a fire involving the complete combustion of all combustible materials within a given fire area.
No credit is taken for the limitation of fire damage by automatic or manual fire suppression.
The combustible loading within the subject fire areas consists primarily of cable, with some loading due to battery casing plastic. All cable used within the NSEB conforms to IEEE Standard 383 for fire retardance.
The hazards within the building are isolated by the division of the NSEB into distinct fire areas, separated by rated fire barriers.
Redundant equipment within the NSEB is additionally separated by the central corridors, which are protected by smoke detectors and a wet-pipe sprinkler system.
Therefore, a fire in any zone would affect only one train and the redundant train would not be affected by the fire.
Each of the six subject fire areas contains both heat detectors and ionization smoke detectors. Actuation by either type of detector results in an alarm in the Control Room to provide warning of a fire in its incipient stage and ensures prompt fire brigade response.
Safety Antlysis Report Log No. 1081 Proposed Amendment No. 173 Page 3 of 4 General Design Criterion 3 requires that fire fighting equipment appropriate to the hazards be installed.
Fire extinguishers are provided within or adjacent to each area for suppression and extinguishment of a developing fire.
In addition, large 50 psi wheeled halon extinguishers are staged in the vicinity of the subject fire zones.
The fire hazards analysis demonstrates that the construction features, low combustible loadings, and equipment layout within the NSEB serve to limit potential fire damage without reliance on automatic suppression.
The manual fire fighting equipment is selected specifically to provide sufficient extinguishing capability for the fire hazards within each area of the NSEB, and to limit damage to vital equipment from fire fighting activities.
Summary PA 173 removes NSEB CO, zones 75 through 80 from those required to be The change will allow permanent disabling of CO operable by TS 3.14.4.
fire suppression systems in these zones to provide an operational enhanc,ement and to improve personnel safety.
The probability of occurrence or the consequences of an accident or malfunction previously evaluated in the Safety Analysis Report will not be increased because the fire hazards analysis demonstrates that the construction features, low combustible loadings, and equipment layout within the NSEB serve to contain the postulated fire within the given fire area and limit potential fire damage to one train of systems important to safety without reliance on automatic fire suppression.
The installed manual fire fighting equipment provides additional fire suppression capabilities in these areas.
The possibility for an accident or malfunction of a different type than any evaluated previously in the Safety Analysis Report will not be created because the NSEB Train A and Train B equipment credited for post-fire safe shutdown is protected in actordance with the requirements of 10 CFR 50, Appendix R.
The protection exceeds that required to ensure damage from a single fire will be limited to one train.
The margin of safety as defined in the basis for any TS is not reduced because adequate fire suppression capability is available to confine and extinguish fires occurring where safety-related equipment or redundant systems required for safe shutdown are located.
The fire hazards analysis demonstrates that the construction features, low combustible loadings, and equipment layout within the NSEB serve to limit potential fire damage without reliance on automatic suppression.
Smoke and thermal detectors are installed in each area to provide early warning in the Control Room for prompt fire brigade response and manual fire fighting.
The manual fire fighting equipment is selected specifically to provide sufficient extinguishing capability for the fire hazards within each area of the NSEB and l',mit dama p to vital equipment from fire fighting activities.
The implementation of PA 173 does not involve an IJnreviewed Safety Question.
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Safety Analysis Report Log N3. 1081 Proposed Amendment No. 173 Page 4 of 4 NO SIGNIFICANT HAZARDS CONSIDERATION The District has reviewed the proposed changes against each of the criterion of 10 CFR 50.92, and bt. sed on the discussion in the above safety analysis the District has concluded that:
A sigrdficant increase in the probability or consequences of an accident previously evaluated in the SAR will not be created because...
The construction features, low combustible loadings, and equipment layo.it within the NSEB serve to contain the postulated fire within the given fire area and limit potential fire damage to one train of systems important to safety without reliance on automatic fire suppression.
The proposed changes will not create the possibility of a new or different type of accident previously evaluated in the SAR because...
The NSEB Train A and Train B equipment credited for post-fire safe shutdown is protected in accordance with the requirements of 10 CFR 50, Appendix R.
The proposed changes will not involve a significant reduction in the margin of safety because...
Adequate fire suppression capability is available to confine and extinguish fires occuring where safety-related equipment or redundant systems important to safe shutdown is located.
Based on the above discussion, the District concludes that the proposed changes do not constitute any significant hazard to the public, and in no way endanger the public's health and safety.
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V Safety Analysis Report Log N3. 1081 Proposed Amendment No. 173 Page 4 of 4 I
NO SIGNIFICANT HAZARDS CONSIDERATION The District has reviewed the proposed changes against each of the criterion of 10 CFR 50.92, and based on the discussion in the above safety analysis the District has concluded that:
A significant increase in the probability or consequences of an accident previously evaluated in the SAR will not be created because...
The construction features, low combustible loadings, and equipment layout within the NSEB serve to contain the postulated fire within the given fire area and limit potential fire damage to one train of systems important to safety without reliance on automatic fire suppression.
The proposed changes will not create the possibility of a new or different type of accident previously evaluated in the SAR because...
The NSEB Train A and Train B equipment credited for post-fire safe shutdown is protected in accordance with the requirements of 10 CFR 50, Appendix R.
The proposed changes will not involve a significant reduction in the margin of safety because...
Adequate fire suppression capability is available to confine and extinguish fires occuring where safety-related equipment or redundant systems important to safe shutdown are located.
Based on the above discussion, the District concludes that the proposed changes do not constitute any significant hazard to the public, and in no way endanger the public's health and safety.
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