ML20247G085
| ML20247G085 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/20/1989 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20247G006 | List: |
| References | |
| NUDOCS 8907270317 | |
| Download: ML20247G085 (22) | |
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UNITED STATER.
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g NUCLEAR REGULATORY COMMISSION k***.*[j WASHINGTON, D. C. 20555 SAFETY EVALUATION REPORT EXEMPTIONS FROM 10 CFR S0, APPENDIX R SALEM GENERATIFG STATION, UNITS 1 AND 2 DOCKET NOS. 50-272/311 1
INTRODUCTION By letter dated July 15, 1988, Public Service Electric and Gas Company, the licensee, requested approval of exemptions from the technical requirements of Section III.G of Appendix R to 10 CFR 50 in fourteen fire areas and a " generic" exemption that relates to conditions in a number of plant locations. This sub-mittal supplements and amends information contained in previous letters to the staff including those dated January 31, 1985 and January 17, 1986.
The most recent letter includes information pertaining to exemptions which had previously been approved by the staff. However, the staff has concluded that sufficient new information exists to issue a revised safety evaluation pertaining to those exemptions, j
Section III.G.2 of Appendix R requires that one train of cebles and equipment necessary to achieve and maintain safe shutdown be maintLined free of fire damage by one of the following means:
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Separation of cables and equipment and associated non-safety circuits of redundant trains by a fire barrier having a 3-hour rating. Structural steel forming a part of ar supporting such fire barriers shall be protect-ed to provide fire resistance equivalent to that required of the barrier; 2.
Separation of cables and equipment and associated non-safety circuits of redundant trains by a horizontal distance of more than 20 feet containing no intervening combustibles or fire hazards.
In addition, fire det?ctors 1
and an automatic fire suppression system shall be installed in the fire area; and 3.
Enclosure of nbles and equipment and associated non-safety circuits of one redundant train in a fire barrier having a 1-hour rating.
In addition, i
fire detectors and an automatic fire suppression system shall be installed in the fire area.
If these conditions are not met,Section III.G.3 requires an alternative shut-duwn capability independent of tha fire area of concern.
It also requires that i
a fixed fire suppression system be installed in the fire area of concern if it contains a large concentration of cables or other combustibles. These alter-native requirements are not deemed to be equivalent; however, they provide equivalent protection for those configurations in which they are accepted.
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Because it is not possible to predict the specific conditions under which fires may occur and propagate, the. design basis protective features are specified in the rule rather than a design basis fire. Plant specific features may require protection different from the measures specified in Section III.G.
In such a
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case, the licensee must demonstrate, by fire hazards analysis, that existing protection in conjunction with proposed modifications will provide a level of safety equivalent to the technical requirements of Section III.G of Appendix R.
In summary,Section III.G is related to fire protection features for ensuring that systems and associated circuits used to achieve and maintain safe shutdown
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are free of fire damage. Fire protection configurations must either meet the specific requirements of Section III.G or an alternative fire protection I
configuration must be justified by a fire hazard analysis.
The staff's general criteria for accepting an alternative fire protection configuration are the following:
The alternative assures that one train of equipment necessary to achieve hot shutdown from either the control room or emergency control stations is free of fire damage.
The alternative assures that fire damage to at least one train of equip-I ment necessary to achieve cold shutdown will be limited such that it can be repaired within a reasonable time (minor repairs with components storedonsite).
1 Modifications required to meet Section III.G would not enhance fire protection safety above that provided by either existing or proposed alternatives.
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l Modifications required to meet Se: tion III.G would be detrimental to i
overall facility safety.
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2 EXEMPTION, STATION WIDE 2.1 Exemption'Pequested An' exemption was requested from Section III.G.2.a. to the extent that 1 1/2-hour fire rated doors and dampers, 1-hour fire-rated ventilation ducts and.their pen-etration seals, and non-rated' equipment hatches do not provide 3-hour fire-rated barriers between areas containing redundant shutdown systems, equipment, cables and associated circuits.
'2.2 ' Discussion l'
'In several locations throughout the plant (delineated in the licensee's July 15, 1988 letter) openings exist in 3-hour fire-rated walls-and floor / ceiling assemblies.
These openings are protected by 11/2-hour rated fire doors or dampers,1-hour rated ventilation ducts and seals, or non-fire-rated steel hatches, y
The nature of the fire hazard in the areas adjacent to these openings' varies significantly. However, where a significant in-situ combustible loading exists in an area, the licensee has committed to implement certain plant modifications which include:
Replacing certain doors and dampers with 3-hour fire-rated assemblies; Installation of additional fire dete,ctors; or Converting existing manually actuated fire suppression systems to automatic actuation.
These modifications supplement existing fire protection which includes automatic-fire detection systems, manual fire fighting equipment and fire-rated cable enclo-sures which protect one safe shutdown division as described in Appendix A to the July 15, 1988 submittal.
The fire severity (as determined from the ASTM E-119 time-temperature curve) in the remaining areas varies from 1 minute to 46 minutes. The licensee also jus-tifies the exemption on the basis that in some locations fire spread through the subject barriers would not damage more than one shutdown division.
2.3 Evaluation The technical requirements of Section III.G.2.a. have not been met in the subject i
lontions because the 3-hour fire barriers which separate redundant shutdown divisions contain openings which are not protected by equivalently fire-rated doors or fire dampers.
The staff was originally concerned that there may be significant quantities of combustible materials, which if ignited, would produce a fire.of sufficient intensity and duration to penetrate the barrier and spread to adjoining plant locations causing damage to redundant safe shutdown systems.
However, the locations where a significant combustible loading exists are either protected by automatic fire detection and suppression systems or the licensee has committed to implement additional modifications as described above. Where this is not the case, the potential fire severity is less than the existing 2-1
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4 doors, dampers, ventilation ducts and cable enclosures, with conservative margin.
1 Where non-rated steel hatches exist either the area below is protected by an automatic fire suppression system or potential fire spread up through the hatch will not affect redundant shutdovn systems.
With regard to the hatches, the staff expressed a related concern that use of hose streams in one fire area might cause water to flow downward through an
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unsealed hatch and damage redundant shutdown equipment belo*.'.
The. licensee 1
affirmed that no water sensitive electronic components exist in proximity to the hatches which would be affected under such a scenario. On this basis only, this issue is considered closed.
With regard to the dampers, the staff was also concerned that the fire dampers might not function under air flou conditions (ref. 10 CFR Part 21 notification l
by Ruskin Manufacturing). However, as confimed during the Septenher 1987 Appen-dix R compliance inspection, the licensee is performing operational tests of the.
i dampers under airflow conditions. On this basis, this issue is considered closed.
2.4 Conclusion Based on the above evaluation, the staff concludes that the licensee's alterna-tive fire protection configuration, including the proposed modifications, pro-vides an equivalent level of safety to that achieved by compliance with Appen-dix R to 10 CFR 50. Therefore, the licensee's exemption request for the lack of 3-hour rated barriers in the locations de.lineated in Appendix A to the July 15, 1988 letter to the staff is granted.
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3.1 Exemption Requested The licensee requested an exemption from Section III.G.3 of Appendix R to 10 CFR 50 to the extent it' requires a fixed fire suppression system for an area where alternate shutdown capability is provided. Specifically, the Salem Unit 1 & 2 control room complex does not have a fixed fire suppression system.
3.2 Discussion The physical configuration of the control room complex, including perimeter construction, fire hazards and existing fire protection features is as described in' Enclosure 1 of the licensee's July 15, 1988 letter.
L Although the walls separating the two control rooms are not fire walls, the doors b
- leading to the control rooms are rated _for. 3/4 hour. The. doors are marked as fire doors and must remain closed. They are also equipped with automatic door clo-sures. The doors have been included in the fire door list and are governed as a Technical Specification item. The restrictions on these doors are designed to prevent the propagation of smoke from one control room to the other.
The Unit I ventilation equipment provides cooling for the Unit 1 control complex, the corridor between the two control rooms and the peripheral rooms that are shared by both units. The Unit 2 ventilation e(uipment provides cooling for the Unit 2 control complex. The ventilat' ion systems for both units have been balanced to maintain equal pressure in both control rooms. Tests have been per-formed and it has been confirmed that smoke does not propagate between control rooms when the ventilation systems are balanced. The damper vanes are mechanically. locked in position to maintain the pressure balance.
In the event.that fire.were to propagate from one control room to the next the licensee has affirmed that the capability exist to bring both units to a safe shutdown condition.
The licensee justified the exemption on the basis of the existing fire protection and the continuous presence of control room operators.
3.3 Evaluation The technical requirements of Section III.G.3 are not met in the control room i
because of the' lack cf a fixed fire suppression system.
The staff was originally concerned that a fire of significant magnitude could occur within the control room complex. However, the existing combustible mate-rials are dispersed throughout the area. The automatic fire detection system, coupled with the continuous presence of control room operators, provides reason-able assurance that a fire will be discovered in its initial stages before sig-nificant propagation and room temperature rise occurs. At such a point in time, the fire would be expected to be extinguished by plant oocrators or the fire brigade before much damage occurred to plant safety systems.
If rapid fire 3
spread occurred before intervention by plant personnel, the control room could
.be evacuated and safe plant shutdown achieved using the alternate shutdown capability, which the licensee has affirmed is physically and electronically 3-1 l
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independent of the control room, and emergency shutdown procedures. Therefore, l
the absence of a fixed fire suppression system has no safety significance.
3.4 Conclusion Based on its evaluation, the staff concludes that the lidensee's alternate i
fire protection configuration provides an equivalent level of fire protection to that achieved by compliance with the requirements of Appendix R to 10 CFR 50, Therefore, the licensee's request for exemption from the requirement for j
a fixed fire suppression system in the control room complex is granted.
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i 4 MECHANICAL PENETRATION AREAS - ELEVATION 78 FEET AND 100 FEET (FIRE AREA 1
& 2 FA-MP-781) 4.1 Exemption Requested An exemption was requested from Section III.G.2.0 to the extent that it requires an automatic fire suppression system installed in a fire area that contains redundant safe shutdown equipment.
4.2 Discussion This fire area consists of the mechanical penetration areas on elevations 78 feet and 100 feet of the auxiliary building.
It is constructed of reinforced concrete with 3-hour fire rated barriers. Doors, dampers, and HVAC duct penetrations are not 3-hour fire rated; however, these are the subject of a generic exemption previously evaluated to be acceptable. The fire load in this area is low (less than 10,000 Btu per square foot) and there are no fire hazardous equipment or concentrated heavy fire loads in the area. The low fire loads of 10,000 Btu per square faot translates into a fire severity of less than 10 minutes on the ASTM E-119 time-temperature curve.
The redundant equipment located in this area include piping and valves for the following:
component cooling system (CCS) service water system residual heat removal system safety injection system.
The existing fire protection includes an area-wide fire detection system, fire extinguishers, and hose stations.
4.3 Evaluation The fire protection in this fire area does not comply with the technical requirements of Section III.G.2.C of Appendix R because an automatic fire suppression has not been installed in an area containing redundant divicions of shutdown equipment.
There was a concern that a fire in this fire area could cause the loss of normal shutdown capability. However, the fire load in this area is low (less than 10,000 Btu per square foot). Because of the low combustible loading, a fire of significant magnitude or duration is not expected to occur. An area-wide fire detection system is available in this area and in adjacent areas. Therefore, there is reasonable assurance that a fire in this fire area will be detected in its early stages and extinguished by the fire brigade before adjacent safety-related areas are threatened. Also, the expected low fire severity would not be a threat to piping and valves.
4.4 Conclusion Based on the above evaluation, it is concluded that the existing fire protection features already in place combined with the alternative shutdown 4-1
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capability for the above described fire' area provided a level of fire
. protection equivalent to the technical requirements of Section III.G.2.0 of 1
EAppendix.R.~ Therefore, the. exemption.is granted..
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e 5 REACTOR PLANT AUXILIARY EQUIPMENT AREA - ELEVATION 100 FT. AND 110 FT.
(AREAS 1 & 2 FA-AB-1000)
UPPER ELECTRICAL PENETRATION AREA (AREAS 1 & 2 FA-EP-100G)
INNER PIPING PENETRATION AREA (AREAS 1 & 2 FA-PP-100H)
REACTOR PLANT AUXILIARY BUILDING - ELEVATION 64 FT. (AREAS 1 & 2 FA-AB-648) 5.1 Exemptions Requested The licensee requested exemptions from the requirements of Section III.G.2 of Appendix R to 10 CFR 50 in the above-referenced areas to the extent that it requires the separation of redundant safe shutdown cables and equipment by 1-hour fire-rated barriers plus automatic fire suppression and detection systems. Specifically, these locations are not protected by automatic fire suppression systems or area-wide fire detection systems.
5.2 Discussion The physical configuration of the subject fire areas, including perimeter construction, fire hazards and existing fire protection features is as described in Enclosure 1 to the licensee's July 15, 1988 16tter.
The staff was initially concerneo that although the licensee has been explicit as to the shutdown-related cables located in the areas not all of the redundant post-fire safe shutdown components had been identified. The licensee affirmed, however, that the only redundant safe shutdown components present in these locations were those specifically identified in the exemption requests.
The licensee committed in the July 15, 1988 letter to protect cables associated with one safe shutdown path in a 1-hour fire-rated barrier.
In Fire Areas 1 & 2 FA-EP-1006, in lieu of protecting the air supply and chilled water cabling, the non-fire-affected unit's emergency control air compressor will be utilized.
The licensee justifies the exemptions on the bases of the limited fire loading, the existing fire protection and the proposed mor'ifications.
5.3 Evaluation The technical requirements of Section III.G.2 are not met in the subject loca-tions because of the lack of automatic fire suppression systems. The absence of area-wide fire detection systems is not considered a non-conformance. Generic Letter 86-10 stipulates that where partial coverage automatic fire detection and sup.5ression exist in an area, licensees may perform a fire hazards evaluation to justify the lack of complete coverage. The staff considers the summary analyses contained in the exemption requests as being sufficient to satisfy the guidelines issued in the Generic Letter.
With regard to the absence of an automatic fire suppression system, the staff was originally concerned i; hat a fire could occur in the subject areas and damage cables or components of both shutdown divisions.
However, the principal fire j
hazard in these locations is combustible cable insulation. The remaining com-
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l bustibles are of a type and quantity that do not represent a significant hazard.
i A fire in these areas would be characterized initially by smoldering combustion with limited heat release. The smoke from a fire would be detected automatic-l ally by the existing fire detection system or by plant operators. The fire l
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brigade would be dispatched to the area and would extinguish the flames using j
manual fire fighting equipment.
If rapid fire propagation or if significant i
room temperature rise occurred before the arrival of the brigade, the proposed 1-hour U re barrier would provide a sufficient degree of passive protection to assure that one safe shutdown division would remain free of fire damage.
In the upper electric 61 penetration area redundant air supply and chilled water cablitio is vulnerable to damage. The licensee has proposed to use the opposite (non-fire-affected) unit's emergency control air compressor in the event of a fire.
However, the licensee has not proposed to adopt technical specifications to assure that this capability w!11 be avaiiable. The specific concern is that if the opposite unit is in an outage, the emergency control air compressor may not be available.
The lack of technical specifications for alternate shutdown capability systems conflict with the guidance issued in Generic Letters 81-12 and 88-12.
4 5.4 Conclusion Based on this evaluation the staff concludes that, except for the upper electri-cal penetration area, the licensee's alternate fire protection configuration with the proposed modifications, provides an equivalent level of safety to that achieved by compliance with Appendix R.
Therefore, the licensee's request for exemption from the requirement for an automatic fire suppression system in the above-referenced areas is granted In the upper electrical penetration area, the exemption is denied.
The licensee's request for exemption per-taining to the lack of area-wide automatic fire detection in these areas is not needed.
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6 460V SWITCHGEAR ROOM (AREAS 1 & 2 FA-AB-84A)
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LOWER ELECTRICAL PEFTRATION AREA (AREAS 1 & 2 FA-EP-78C) l 4160V SWITCHSEAR RI (AREAS 1 & 2 FA-AB-64A) j 6.1 Exemptions Requested The licensee requested exemptions from the requirements of Section III.G.2 of l
Appendix R to 10 CFR 50 in the above-referenced areas to the extent that it requires the separation of redundant safe shutdown equipment by 1-hour fire-rated barriers plus automatic suppression and detection systems. Specifically, redundant safe shutdown systems are not protected by complete, 1-hour fire i
barriers.
In addition, the fire suppression system in the 4160V switchgear room is manually actuated.
6.1 Discussion The physical configuration of the subject fire areas, including perimeter construction, fire hazards and existing fire protection is as described in to the licensee's July 15, 1988 letter.
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The staff was initially concerned that not all redundant safe shutdown components had been identified in the licensee's submittal for these areas. The licensee affirmed however that the only redundant safe shutdown components were those j
specifically identified in Enclosure 1.
The licensee comraitted to protect one division of safe shutdown cables in a j
1-hour fire-rated enclosure as described in the July 15, 1988 letter.
The licensee justified the exemptions on the basis of the existing protection and proposed modifications. Additionally, in the 460V switchgear room, the licensee indicated that an alternate shutdown capability exists for redundant shutdown cables that are not encompassed by the above-referenced modification.
6.3 Evaluation I
The technical requirements of Section III.G.2 are not met in the subject loca-tions because certain redundant safe shutdown cables and components are not pro-tected by complete (wall-to-wall, floor-to-ceiling) 1-hour fire barriers. Also, the 4160V switchgear room is protected by a manually actuated fire suppression system. The staff issued an exemption for the lack of an automatic fire suppres-sion system in the 4160V switchgear room by letter dated June 17, 1983.
1 The principal concern with the level of fire protection in these fire areas was i
that because of the absence of complete 1-hour fire-rated barriers between redun-dant trains of safe shutdown equipment and cables, a fire of significant magni-tude could develop and damage redundant shutdown systems.
However, the fire load in these locations is low.
If a fire were to occur, it is expected that it would develop slowly, with initially low heat release and slow room tempera-ture rise.
Because of the presence of the early warning fire detection systems in all three areas, any fire would be detected in its incipient stages. Also, each of these areas is protected by an area-wide fire suppression system. The alarms from these detectors and fire suppression systems are annunciated in the control room. The fire brigade would ultimately be dispatched and would l
extinguish the fire manually using hose lines or portable extinguishers. Until l
the fire was put out, the existing fire barriers and the 1-hour fire rated cable l
wrapping between the redundant shutdown systems would provide sufficient passive 6-1 l
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remain free of fire damage. Therefore, the lack of a complete barrier to protect these systems is not considered safety significant.
6.4 Conclusion Cased on the above evaluation, the staff concludes that the licensee's alternate fire protection configuration plus the pro)osed modifications provides and equi--
Valent level of fire protection to that aclieved by compliance with Appendix R.
Therefore, the licensee's request for exemption from the requirement for a com-plete 1-hour fire-rated barrier in the subject areas is granted. The staff's' evaluation of the June 17, 1983 exemption request for the lack of an automatic fire suppression systen in the 4160 V switchgear room remains valid.
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9 7 REACTORPLANTAUXILIARYEQUIPMENTAREA-ELEVATION 84FT.(AREASI&2 FA-AB-84B)-
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I 7.1 Exemption Requested The licensee requested an exemption from the requirements of Section III.G.2 of Appendix R to 10 CFR 50 to the extent that it requires the separation of redun-dant safe shutdown cables and equipment by 1-hour fire-rated barriers plus auto-matic fire detection and suppression systems. Specifically, area-wide detection and suppression systems are not provided. Additionally, auxiliary feedwater (AFW) system and chemical and volume control system (CVCS) equipment are not separated by complete fire rated barriers.
7.2 Discussion The physical configuration of this location, including perimeter construction, fire hazards, existing fire protection features and the inventory of safe shut-down systems is as described in Enclosure I to the licensee's July 15, 1988 letter.
To enhance fire protection in the area, the licensee proposed to implement the following modifications:
Installation of partial 1-hour fire-rated barriers so as to achieve at least 30 feet of spatial separation,of shutdown related cables; Expand the existing wet-pipe aprinkler system in the charging pump area to provide full coverage around the pump; Enhance the sprinkler systems which protect the auxiliary feedwater pumps as described in the July 15, 1988 letter; i
The No. 11 (21) component cooling water _(CCW) pump and the No. 11 (21) component cooling heat exchanger will be enclosed in a 3-hour fire-rated cubicle as described in the above-referenced letter.
The licensee justifies the exemption on the bases of the limited fire loading, existing fire protection and proposed modifications.
7.3 Evaluation The technical requirements of Section III.G.2 are not met in this area because 1
AFW and CVCS equipment are not separated by complete (wall-to-wall, floor-to-l ceiling) 1-hour fire-rateu barriers. Also, the intervening space between redun-dant shutdown cables contains a small quantity of combustible materials. The absence of area-wide fire detection and suppression systems is not considered a non-conformance.
Generic Letter 86-10 stipulates that where partial coverage automatic fire detection and suppression systems exist in an area, licensees may perform a fire hazards evaluation to justify the lack of complete coverage.
The staff considers the summary analyses contained in the exemption request as being sufficient to satisfy the guidelines issued in the Generic Letter.
With regard to the partial fire barriers and intervening combustibles the staff was initially concerned that a fire which originates in this area could j
achieve a level of intensity and propagate to such an extent as to damage both l
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i shutdown divisions. However, the locations where significant fire hazards or vulnerable systems are present are protected by an automatic fire detection sys-3 tem.
If a fire occurred the system would detect it in its initial' stages and
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transmit an alarm directly to the control room. The plant fire brigade would j
be dispatched to the scene and would extinguish the fire using portable fire fighting equipment. These same. locations are also protected by an automatic fire suppression system. -If rapid fire propagation or room temperature rise occurred the system would actuate to control the. fire and to protect vulnerable 1
systems. Pending arrival of the brigade and/or the actuation of the fire sup-1 pression system the fire barriers and spatial separation between the redundant j
cables and components provide a sufficient degree of passive protection to assure that at least one shutdown division will remain free of fire damage.
7.4 Conclusion Based on its evaluation the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of fire safety to that achieved.by compliance with Appendix R.
Therefore the licensee's rt. quest for exemption from Section III.G.2 is granted.
The licensee's request for i
exemption from the requirement for area-wide fire detection and suppression systems in this area is not needed.
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o 8 RESIDUAL HEAT REMOVAL PUMP AND HEAT EXCHANGER AREAS (AREAS 1 & 2 FA-AB-45A andB) 8.1 Exemption Requested The licensee requested approval of an exemption from the technical requirements of Section III.G.2 of Appendix R to 10 CFR 50 to the extent that it requires the separation of redundant safe shutdown systems by complete 3-hour fire-rated bar-riers. Specifically, redundant cables in these areas are separated by 3-hour fire rated walls with open penetrations.
8.2 Discussion The physical configuration of this location including perimeter construction, fire hazards, existing fire protection features and the inventory of safe shut-down systems is as described in Enclosure 1 to the licensee's July 15, 1988 letter.
To enhance fire protection the licensee proposed to implement the following modifications:
Extend the fire detection system throughout elevation 55 feet with the
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exception of the RHR heat exchangers; Seal the openings around the ventilation duct which penetrates the fire wall on elevation 45 feet.
Enclose cables associated with one shutdown division on elevation 55 feet
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in a 1-hour fire barrier such that 20 feet of spatial separation is achieved to their redundant counterpart.
The licensee justified the exemption on the basis of the existing protection and the proposed modifications.
8.3 Evaluation The technical requirements of Section III.G.2 are not met in these areas because redundant safe shutdown cables are not separated by a complete (wall-to wall, floor-to-ceiling) 3-hour fire-rated barrier.
The staff was originally concerned that a fire of significant magnitude could occur which might propagate through the openings in the fire wall and damage both shutdown divisions. However, the fire loading in these areas is minimal.
If all of the combustible materials ignited and were consumed, the resulting fire would be of 5 minutes duration as determined by the ASTM E-119 Time Temperature Curve.
The combustibles consist of cable insulation and lubricating oil in pumps. A fire involving these materials would be characterized, initially, by slow burning, low heat release and the production of moderate quantities of. smoke. The smoke detection system would actuate and alarm automatically in the control room.
The fire brigade would be dispatched and would put out the fire before rapid burning
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occurred. Pending arrival of the brigade, the products of combustion would be j
largely confined to the area of origin.
Because of the openings in the fire l
wall some smoke and hot gases would spread into the adjoining fire area.
It is the staff's judgement, however, that the products of combustion would ba suffi-ciently cooled and dissipated so as not to represent a signif t:: ant threat to the 8-1 i
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' redundant cables Also, the cables themselves are not immediately vulnerable to
- smoke damage.
Failure'due to heat damage would not occur until well after ini-
- tial-ignition. The staff concludes that sufficient time exists for the fire brigade to intervene to suppress the fire prior to damage to redundant systems.
The -lack of. a complete 3-hour fire barrier is, therefore, not considered safety significant.
8.4 Conclusion Based on its evaluation the staff concludes that the licensee's alternate fire protection configuration, including the proposed modifications provides an equivalent level of fire safety to that achieved by compliance with Appendix R.
Therefore, the licensee's request for exemption from the requirement for a complete 3-hour rated fire barrier between redundant systems in the subject area is granted.
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9 CONTAINMENT.(AREA 1 & 2 FA-RC-78) j i
l 9.1 Exemption Requested The licensee requested approval of an exemption from the requirements of Section III.G.2 of Appendix R to 10 CFR 50 to the extent that it requires that i
redundant cables and equipment within containment be separated by at least 20 l
feet of horizontal distance free of intervening combustibles or be separated I
by a radiant energy shield.
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l 9.2 O_iscussion The physical configuration of redundant systems within containment, the existing
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fire hazards and available protection are as described in Enclosure 1 to the i
licensee's July 15, 1988 letter.
To enhance fire safety the licensee has proposed to install a localized ff re suppression system to protect Panel 335 which contains redundant channels of I
pressurizer pressure and level instrumentation.
The licensee justifies the exemption on the bases of the limited fire loading, the existing fire protection and the proposed modification.
l 9.3 Evaluation The technical requirements of Section III.G.2 are not met within containment because redundant systems at the pressurizer and at Panel 335 are not separated by at least 20 feet or separated by a radiant energy shield.
The staff was originally concerned that a fire could occur which would damage redundant shutdown divisions.
However, the principal fire hazard within con-tainment, the lube oil in the reactor coolant pumps, has been mitigated by the existing oil collection system and the water spray system over the RCP lobe oil lift pump and its discharge ' lines.
The remaining combustible materials are dis-persed tnroughout the area.
If a fire were to occur, the resulting smoke and hot gases would rise up into the upper areas of the containmen+. and away from vulnerable shutdown systems. The upper area would act as an effective heat sink until the fire self-extinguishes or is put out by the plant fire brigade. Pend-ing fire extinguishment the existing spatial separation between redundant sys-tems, except for the subject locations, would assure that at least one shutdown
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division would remain free of fire damage.
At Panel 335, the licensee will install an automatic fire suppression system thet will provide reasonable assurance that at least one channel of pressurizer pressure and level instrumentation will remain free of damage.
No additional fire protection modifications are feasible at the pressurizer to enhance the existing level of fire safety.
It is the staff's. judgement that it is not credible to postulate a significant fire in the vicinity of the pressur-izer which would prevent safe shutdown from being achieved.
I 9.4 Conclusio_n, Cased on its evaluation, the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of fire safety to that 9-1
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exemption from the requirements of Section III.G.2 for at least 20 feet of sep-
- aration between redundant shutdown systems at Panel 35 and at the pressurizer within containment is' granted.
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10 PIPE. TUNNEL - ELEVATION 84 FEET (AREA 12 FA-PT-84) 10.1 Exemption Requested The licensee requested approval'of an exemption from the technical requirements of Section III.G.2 of Appendix R to 10 CFR 50 to the extent that it requires that redundant shutdown systems be separated by at least 20 feet free of inter-vening combustibles and be protected by automatic fire detection and suppression systemt. Specifically, redundant systems are separated by less than 20 feet and the tunnel is not protected by an automatic fire suppression system.
10.2 Discussion The physical description of this area, including perimeter construction, fire hazards, existing fire protection and configuration of safe shutdown systems
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is as described in Enclosure 1 to the licensee's July 15, 1988 letter.
To enhance fire safety the licensee committed to install a fire detection system throughout the pipe tunnel which will transmit an alarm automatically to the control room.
The licensee justified the exemption on the bases of the limited fire loading, the inaccessibility of the tunnel and the proposed modification.
10.3 Evaluation The technical _ requirements of Section III.G.2 are not met in this area because redundant shutdown divisions are separated by less than 20 feet horizontal dis-tance and the tunnel is not protected by an automatic fire suppression system.
i The fire loading in the turnel is minimal.
If all of the combustibles ignited and were consumed the resulting fire would be about 7 minutes in duration as determined from the ASTM E-119 Time Temperature Curve.
Because access to the area is limited to three hatchways the potential for accumulation of significant quantities of transient combustibles or ignition sources is considered remote.
Nevertheless, the staff was concerned that if a fire did occur, it would not be detected in sufficient time for the fire brigade to intervene to limit damage.
The licensee's commitment to install a smoke detection system in the area has eliminated that concern. The staff concludes that with the addition of the detection system, the limited fire hazard in the area and the restricted access, there is reasonable assurance that at least one shutdown division can be maintained free of fire damage.
10.4 Conclusion Based on its evaluation, the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of safety to that achieved by compliance with Appendix R.
Therefore the licensee's request for exemption from the requirement of Section III.G.2 for 20 feet of separation between redun-dant shutdown systems and an automatic fire suppression system in the pipe tunnel is granted.
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11 CO, EQUIPMENT ROOM - ELEVATION 84 FEET (AREAS 1 & 2 FA - DG - 84F) 11.1 Exemption Requested The licensee requested approval of an exemption from the technical requirements of Section III.G.2 of Appendix R to 10 CFR 50 to the extent that it requires separation of redundant shutdown systems by 1-hour fire barriers and protection by automatic fire detection and suppression systems. Specifically, redundant shutdown cables are not protected by an automatic fire suppression system.
11.2 Discussion The physical descripHon of this area, including perimeter construction, fire i
hazards, existing fih protection and configuration of safe shutdown cables is
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as described in Enclosure 1 to the licensee's July 15, 1988 letter, j
To enhance fire safety the the licensee committed to install an area-wide automatic fire detection system and to protect cables for one safe shutdown division in a 1-hour fire-rated barrier.
The licensee justified the exemption on the basis of the low fire loading, the existing protection and the proposed modifications.
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11.3 Evaluation The technical requirements of Section III'G.2 are not met because of the lack of an automatic fire suppression system.
l The staff was concerned that because of the absence of an area-wide fire i
suppression system a fire of significant magnitude could develop and damage redundant shutdown systems. However, the fire loading in the location is low.
If all of the combustibles were totally consumed in fire it would result in an equivalent fire severity of about 20 minutes as determined by the ASTM E-119
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Time Temperature Curve.
Because of installation of the fire detection system j
the staff expects that a fire, if one should occur, would be detected in its
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incipient stages, before significant room temperature rise occurs.
The alarm
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from the detector would be transmitted automatically to the control room.
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fire brigade would be dispatched and would extinguish the fire using portable j
fire fighting equipment Pending arrival of the brigade, the 1-hour fire bar-1 rier would provide sufficient protection to assure that at least one division of safe shutdown systems would remain free of fire damage. Therefore, the i
absence of an automatic fire suppression system is not safety significant.
11.4 Conclusion Based on its evaluation, the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of fire safety to that achieved by compliance with Appendix R.
Therefore, the licensee's request for exemption from the requirements of Section III.G.2 for an automatic fire sup-pression system in the subject area is granted, 11-1 l
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'12l FIRE.BARRIERPENETRATIONS In the July 15,1988: letter'the licensee indicated that the adequacy of fire barrier penetration. seals and fire dainpers has not been < completely validated.-
The. licensee committed to ensure that all penetration seals and fire dampers in
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3 required fire barriers will be either qualifiedEto the design ratir.g-of the pen-
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etrated fire barrier by fire test documentation or determined adequate to with-stand the fire hazard associated with the area. Pending completion of the 1
' licensee's validation effort, this issue will remain open.
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SUMMARY
Based on its evaluation, the staff finds that the following exemptions should' be granted:
Generic exemption pertaining to non-3-hour fire-rated features in 3-hour fire barriers; Lack of a fixed fire suppression system in the control room; Lack of an automatic fire suppression system in the reactor plant auxiliary equipment area, elevations 100 and 110 feet; Lack of an automatic fire suppression system in the inner piping penetration area; Lack of an automatic fire suppression system in tire reactor plant auxiliary building, elevation 64 feet; Lack of an automatic fire suppression system in the mechanical penetration areas, elevations 78 and 100 feet; The lack of complete 1-hour fire rated barriers between redundant shutdown systems in the 460V switchgear room. Also, this area is protec-ted by a manually actuated fire suppression system in lieu of an automatic system; The lack of complete 1-hour fire rated barriers between redundant shutdown systems in the lower electrical penetration area; The lack of complete 1-hour fire rated barriers betwen redundant shutdown systems in the 4160 V switchgear room.
The lack of complete 1-hour fire-rated barriers or 20 feet free of intervening combustibles between redundant systems in the reactor plant auxiliary equipment area, elevation 84 feet; The lack of complete 3-hour fire barriers between redundant shutdown systems in the RHR pump and heat exchanger areas; The lack of 20 feet of separation free of intervening combustibles between redundant shutdown systems in containment; The lack of an automatic fire suppression system and the absence of 20 feet of spatial separation between redundant systems in the pipe tunnel, elevation 84 feet; The lack of an automatic fire suppression system in the CD equipment 2
rooe, elevation 84 feet.
j Based on its evaluation in Section 5 above, the staff denies the licensee's request for exemption in the upper electric penetration area.
Principal Contributor:
D. Kubicki Dated:
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