ML19308A819
| ML19308A819 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/25/1977 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19308A816 | List: |
| References | |
| NUDOCS 7912120609 | |
| Download: ML19308A819 (8) | |
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o UNITED STATES NUCLEAR REGULATORY COMMISSION g
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- E WASHINGTON, D. C. 20S55
'%....,o SAFETY EVALUATI014 BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDitENT NO.
TO LICENSE NO. DPR-38 At1ENDt1ENT NO.
TO LICEilSE NO. DPR-47 AMEhDMENT N0.
TO LICEliSE NO. DPR-55 DUKE POWEi C0ftPANY c
OC011EE HUCLEAR STATION, Ul4ITS NO. 1, 2 AND 3 DOCKET t.0S. 50-269, 50-270 AND'50-287 IhTRODUCTION Following a fire at the Browns Ferry Nuclear Station in fiarch 1975, we initiated an evaluation of the need for improving the fire protection programs at all licensed nuclear power plants. As part of this continu-ing evaluation, in February 1976 we published a report entitled "Recorcendations P. elated to Browns Ferry Fire", NUREG-0050. This report recoamended that improvements in the areas of fire prevention and fire control oe made in most existing facilities and that consideration be given to oesign features that would increase the ability of nuclear facilities to withstand fires without the loss of important functions.
To implement the report's recommendations, the NRC initiated a program for reevaluation of the fire protection programs at all licensed nuclear power stations and for a comprehensive review of all new license applications.
We have issued new guidelines for fire protection programs in nuclear power plants. These guidelines reflect the recommendations in NUREG-0050.
These, guidelines are contained in the following docum,ents:
" Standard Review Plan for the' Review of Safety An'alysis Reports for Nuclear Power Plants," NUREG-75/08i, Section 9.5.1, " Fire Protection," tiay 1976, which includes " Guidelines for Fire Protection for Nuclear Power Plants," (BTP APCSB 9.5-1), May 1,1976.
" Guidelines for Fire Protection for Nuclear Power Plants"( Appendix A to BTP APCSB 9.5-1), August 23, 1976.
" Supplementary Guidance on Information Needed for Fire Protection Program Evaluation," September 30, 1976.
" Nuclear Plant Fire Protection Functional Responsibilities, Administrative Controls and Quality Assurance," June 14, 1977.
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r Duke Power Company (the licensee) has submitted a description of the fire p'rotection program for the Oconee Nuclear Station by letter dated December 31, 1977. This program is under detailed review by the NRC.
In the interim, until we complete our detailed review, we have concluded that it is' appropriate to amend the facility license by incorporating into the Technical Specifications operability and surveillance requirements o for the existing fire protection equipnent and systems.
In addition, the amendment would include administrative requirements for the implementation of the fire protection program.
By letter dated September 28, 1976, we requested the licensee to submit Technical Specifications -for presently-installed fire protection equipment at this facility. The licensee responded by letter of December 31, 1976, stating that Technical Specifications would be submitted by March 1, 1977.
Subsequently, the licensee proposed Technical Specifications by letter dated March 1, 1977. Based on our review and consideration of that response and the responses of other licensees, we modified certain action statements and surveillance frequencies in order to provide more appropriate and consistent specifications which we forwarded to the licensee by letter of June 17, 1977. That letter also requested submittal of appropriately revised specifications.
The licensee responded by letter dated July 18, 1977. We have reviewed the licensee's response and have made modifications where necessary to assure conformance to the fullest extent practicable with our require-ments as set forth in the sanole Technical Specifications pending completion of our ongoing detailed review of fire protection at this facility.
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. DISCUSSION AND EVALUATION The guidelines for technical specifications that we developed and sent to all licensees are based on assuring that the fire protection equip-ment currently installed for the protection of safety related areas of the plant is operable. This assurance is obtained by requiring periodic surveillance of the equipment and by requiring certain corrective actions to be taken if the limiting conditions for operation cannot be met.
These guidelines also include administrative features for the overall fire protection program such &s interim fire brigade requirements, training, procedures, management review and periodic independent fire protection e
and loss prevention program inspections.
The equipment and components currently existing at this facility include,d in the scope of these Technical Specification requirements are fire l
detectors,' the fire suppression systems, the hose stations, and piping and cabling penetration fire barriers. Operability of the fire detection instrumentation provides warning capability for the prompt detection of fires, to reduce the potential for damage to safety related equipment by allowing rapid response of fire suppression equipment. In the event that the minimum coverage of fire detectors cannot be met, hourly fire patrols are required in the affected area until the inoperable instrumentation is restored to operability.
The operability of the fire suppression system provides capability to confine and extinguish fires.
In the event that portions of the fire suppression system are inoperable, alternate backup fire fighting equipment is required to be made available in the affected areas until the inoperable equipment is returned to service.
In the event that the fire suppre3sion water system becomes inoperable, a backup fire protection water system is required within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and a report to the NRC is required within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to provide for prompt evaluation of the acceptability of the corrective measures for adequate fire suppression capability.
The functional integrity of the penetration fire barriers provides protection to confine or retard f1res from spreading to adjacent portions of the facili ty.
During periods of time when a fire barrier is not functional, a continuous fire watch is required to be maintained in the vicinity of the affected barrier to provide fire prevention methods and prompt detection and suppression in the event of a fire.
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We have reviewed the licensee's proposed interim Technical Specifi-cations against our requirements as implemented in the sample Technical Specifications. We have made some modifications to the specifications that were proposed by the licensee in order to make them conform to our requirements. One of the proposed specifications that we changed involves the minimum size of the on-site fire brigade.
In our previous sample Technical Specifications we did not i'dentify the number of members on a fire brigade that we would find acceptable. We have now concluded that minimum number for a typical commercial nuclear power plant to be five (5).
The basis for this conclusion is presented in an attachment to this SER entitled " Staff Position Minimum Fire Brigade Shift Size."
In the report of the Special Review Group on the Browns Ferry Fire (NUREG-0050) dated February 1976, consideration of the safety of operation of all operating nuclear power plants pending the i
completion of our detailed fire protection evaluation was presented.
The following quotations from the report summarize the basis for our i
conclusion that the operation of the plants, until we complete our review, does not present an undue risk to the health and safety of the public.
"A probability assessment of public safety or risk in quantitative terms is given in the Reactor Safety Study (WASH-1400). As the result of the calculation based i
on the Browns Ferry fire, the study concludes that the potential for a significant release of radioactivity from such a fire is about 20% of that calculated from all other causes analyzed. This indicates that predicted potential accident risks from all causes were not greatly affected by consideration of the Browns Ferry fire.
This is one.of the reasons that urgent action in regard to reducing risks due to potential fires is not required.
The study (WASH-1400) also points out that 'rather straight-forward measures, such as may already exist at other nuclear plants, can significantly reduce the likelihood of a potential core melt accident that might result from a large fire.' The Review Group agrees.
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. " Fires occur rather frequently; however, fires involving equipment unavailability comparable to the Browns Ferry fire are quite infrequent (see Section 3.3 [of NUREG-0050]).
The Review Group believes that steps already taken since March 1975 (see Section 3.3.2) have reduced this frequency significantly.
" Based on its review of the events transpiring before, during and after the Browns Ferry fire, the Review Group concludes that the probability of disruptive fires of the magnitude of the Browns Ferry event is small, and that there is no need to restrict operation of nuclear power plants for public safety. However, it is clear that much can and should be done to reduce even further the likelihood of disabling fires and to improve assurance of rapid extinguishment of fires that occur. Consideration should be given also to features that would increase further the abil:ty of nuclear facilities to withstand large fires witi.<a.'. loss of important functions should such fires occur."
Subsequent to the Browns Ferry fire and prior to the Special Review Group's investigation, the Office of Inspection and Enforcement took steps with regard to fire protection.
Special bulletins were sent to all licensees of operating power reactors on March 24, 1975, and April 3,1975, directing the imposition of certain controls over fire ignition sources, a review of procedures for controlling maintenance i
and modifications that might affect fire safety, a review of emergency procedures for alternate shutdown and cooling methods, and a review of flammability of materials used in floor and wall penetration seals.
Special inspections covering the installation of fire stops in electrical cables and in penetration seals were completed at all operating power reactors in April and May 1975. Inspection findings which reflected non-compliance with NRC. requirements resulted in requiring corrective action by licensees. Follow-up inspections have confirmed that licensees are taking the required corrective actions and that administrative control procedures are in place.
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Since these inspection activities and the subsequent Special Review Group recommendations in the 1975 to 1976 time period, there has been no new infonnation to alter the conclusions of the Special Review Group, and the ongoing fire protection program flowing from those conclusions is still adequate.
Therefore, we have found these specifications acceptable on an interim basis until such time that our overall review is complete, required equipment is installed L.nd operable, and final specifications have been developed and issued.
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ENVIRONf1 ENTAL CONSIDERATION We have determined that the planned amendment does not authorize a '
change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this detennination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and pursuant to 10 CFR s51.5(d)(4) that an environmental impact statement or negative declaration. and environ-mental impact appraisal need not be prepared in connection with the issuance of this planned amendment.
CONCLUSION We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the,
i amendment does. not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the prooosed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this planned amendment will not be inimical to the ' common defense and security or to the health and safety of the public.
Date:
November 2 5, 1977
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Staf f ' Position Minimum Fire Grigade Shift Size INTRODUCTION Nuclear power plants depend on the response of an onsite fire brigade for d..fense against the effects of fire on plant safe shutdown capabilities.
In some areas, actions by the fire brigade are the
,only means of fire suppression.
In other areas, that are protected by correctly designed automatic detection and suppression systems, manual fire fighting efforts are used to extinguish:
(1) fires too small to actuate the automatic system; (2) well developed fires if the autenatic system fails to function; and (3) fires that are not completely controlled by the automatic system.
Thus, an adequate fire brigade is essential to fulfill the defense in depth requirements which protect safe shutdown system.s from the effects of fires and,their related combustion by-products.
DISCUSSION There are a number of factors that should be considered in establishing the minimum fire brigade shift size. They include:
- 1) plant gecmetry and size;
- 2) quantity and' quality of detection and suppression systems;
- 3) fire fighting strategics for postulated fires;
- 4) fire brigade training;
- 5) fire brigadg equipment; and
- 6) fire brigade supplements by plant personnel and local fire departnent(s).
In all plants, the majority of postulated fires are in enclosed window-less structures.
In. such areas, the working environment of the brigade created by the heat and smcke buildup within the enclosure, will require the use of self-contained breathing apparatus, smoke ventilation equipment, and a personnel replacement capability.
dertain functions must be performed for all fires, i.e., comand brigade actions, inform plant management, fire suppression, ventilation control, provide extra equipment, and account for possible injuries. Until a site specific review can be completed, an interim minimum fire brigade size of five persons has been established. This brigade size should provide a minimum working number of personnel to deal with those postulated fires in a typical presently operating comercial nuclear power station.
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If the brigade is composed of a smaller number of personnel, the fire attack may be stopped whenever new equipment is needed or a person is injured or fatigued. We note that in the career fire service, the minimum engine company manning considered to be effective for an initial attack on a fire is also five, including one officer and four team members.
It is assumed for the purposes of thi:s position that brigade training and equipment is adequate and that a backup capability of trained individuals exist whether through plant personnel call back or from the local fire department.
POSITIO!!
1.
The minimum fire brigade shift size should be justified by an analysis of the plant specific factors stated above for the plant, after modifications are ccmplete.
2.
In the interim, the minimum fire brigade shift size shall be five persons.
These persons shall be fully qualified to perform their assigned responsibility, and shall include:
One Sunervisor - This individual must have fire tactics training.
He wili assume all command responsibilities for fighting the fire.
During plant emergencies, the brigade supervisor should not have other responsibilities that would detract from his full attention being devoted to the fire.
This supervisor should not be actively engaged in the fighting of the fire.
His total function should be to survey the fire area, ccm:Pand the brigade, and keep the upper 1evels of p1 ant management informed.
Two Itose Men - A 1.5 in'ch fire hose being handled within a window-less enclosure would require two trained individuals.
The two team members are required to physically handle the active hose line and to protect each other while in the adverse environment of the fire.
Two Additional Team Memoers - One of these individuals would be required to supply filled air cylinders to the fire fighting members of the brigade an? the second to~ establish smcke ventilation and aid in filling the air cylinder.
These two individuals would also act as the first backup to the engaged team.
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