ML20205C770
| ML20205C770 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/19/1987 |
| From: | Miraglia F Office of Nuclear Reactor Regulation |
| To: | GENERAL PUBLIC UTILITIES CORP. |
| Shared Package | |
| ML20205C776 | List: |
| References | |
| NUDOCS 8703300256 | |
| Download: ML20205C770 (17) | |
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7590-01 UNITED STATES filCLEAR REGUL ATORY COPPISSION in the Patter of
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1 GENERAL PUBLIC UTil! TIES NUCLEAP
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Docket No. 50-?89
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(Three File Island Fuclear
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Statice, Unit No. 1)
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EXEMPTION I.
General Public Utilities Nuclear (GPUN) Corporation (the licersee) and three co-owners hold Facility Operatirg License No. DPR-50, which authorizes Operation of the Three Mile Island Nuclear Station, Unit No. 1 (TPI-1) (the facility) at power levels not in excess of 2535 megawatts thermal. This license provides, among other things, that the facility is subject to all rules, regulations, and Orders of the Nuclear Regulatory Commission (the Commission or the staff) now or hereafter in effect.
The facility is a pressurized rater reactor located at the licensee's site in Dauphin County, Pennsylvania.
II.
10 CFR 50.40, " Fire Protection," and Appendiy. P to 10 CFR Part 50, " Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979" set forth certain fire protection features required to satisfy the General Desion Criterion related to fire protection (Criterien 3, Appendix A to 10 CFP 50).
Section III.G of Appendix P requires fire protection for equipment impcrtant to safe shutdown. Such fire protection is achieved by various combinations of fire barriers, fire suppression systems, fire detectors, and 8703300256 870329
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separation of safety trains (III.G.?) or alternate safe shutdown equipment free of the' fire area (III.G.3). The objective of this protection is to assure that one train of equipment needed for hot shutdowr. would be undamaged by fire, and that systems needed for cold shutdown could he repaired within 7?
heurs (III.G.1).
III.
By letters dated Februsry ?, 1987, February 11, 1987, February ?P, 1987, and March 10, 1987, the licensee reouested approval of a number of exemptions from the technical requirements of Section III.G of Appendix R to 10 CFR 50 Additional information concerning some exemptions requested was provided in a letter dated February 10, 1987. A description of the exemption requests and a summary of the Commission's evaluation follow.
1.
Ill.G.?; exemption requested to allow manual operation of certain valves and pumps and in some instances providing a roving fire partol in lieu of providino fire protection. The pumps and valves to be marually operated include MU-V-IP (normal makeup flow), MU-V-8 (letdown flow alignment to Makeup Tank or the Reactor Coolant Bleed Tanks), MS-V-?B (main steam block valve for atmospheric steam dump), EF-V-30 A, B, C and D (Emergency Feedwater Flow Control Valves), Nuclear River Cooling Water Pump NR-P-Ic, IC-V-7, 3, 4 (Intermediate Cooling Valves), FU-V-37 (Pakeup Valve), PU-V-1A, IB, PA, PB, 3, 6A and 68 (Letdown Valves), WDL-V-1 and ? (Letdown Valves). IC-V-1A and 1R (Intermediate Coolino Valves), and NR-V-15A and B (Fuclear River Valvesi. The specific components are as described in letters from the licensee dated February ?, 1987 and Parch 10, 1987, w
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The licensee states thet if a fire danaces cables associated with these l
l components, sufficient time exists to manually alian the valves and to manually control the pumps so a:, to achieve and maintain safe shutdown conditions. The time periods within which the licensee must accomplish these actions vary from 20 minutes for certain emergency feedwater system valves to 240 minttes for certain valves in the makeup system. The minimum time frame to establish local control of the intermediate cooling water pumps and the nuclear river cooling water pumps is 30 minutes.
The technical recuirements of Appendix P are not met in the subject areas because cables and components for certain shutdown-related valves and pumps are not provided with fire protection in accordance with the options identified in Section III.G.
The staff has several concerns regardino the reliance on manuel actions in lieu of physical protection of shutdown systems. The first is that plant operators may have to enter the fire area before it is reasonable to expect that habitable conditions may be restored after the fire. The licensee, in the February ?,1987 submittal, identified a number of locations where safe shutdown can only be achieved by reenterino the fire area to assure proper valve alignment. However, in no instance is it necessary to enter these areas before two hours after fire damace occurs. Although it is not possible to predict the nature and duration of a fire in any location, the staff expects that within one hcur a fire would have been detected and controlled and near ambient conditions restored.
This conclusion is based on the description of plant barards and available protection as provided by the licensee in Pevision 7 of the Fire Hazards Analysis Report (FHAP) and staff observations made
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during the Appendix R inspection held in December 1986 The licensee's analyses indicated that an additional hour exists beyonr' the staff's assumptions. This results in a sufficient margin of safety and provides reasonable assurance that manual actions within the fire area can be achieved.
The staff was also cnncerned that fire damane to valve operators would prevent manual valve alignrrent. However, the licensee respondeo to this concern by stating that fire damage to valve operators will not prevent the valve operators from being manually turned.
A further staff concern is that because not all fire areas are physically separated from adjoinino locations by continuous fire-rated construction, fire propagation through non-rated boundaries might prevent operators from performino manual operations. Powever, where fire area boundaries are not completely fire-rated, the licensee indicates that 1) the areas on one or both sides of the boundary are protected by an automatic fire suppression system, or 2) the boundary wall or floor / ceiling forms a continuous non-combustible barrier to the propagation of fire, or 3) the adjoining area into which fire may spread is not relied upon for safe shutdown.
An additional concern is that the post-fire shutdown procedures and available personnel are adequate for the tasks to be performed. The licensee responded that procedures will be prepared in conformance with staff fire protection guidance as provided in Generic Letters 81-12 and 86-10. The staff considers this response acceptable. Powever, the adequacy of these procedures will be confirmed durina the NRC staff's review of the safe shutdown and alternate shutdown capabilities.
The staff's remainina concern is that the manual actions required in locations outside the fire area could actually be accomplished within the
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-s-maximum available time period stipulated by the licensee while a plant fire is underway. As previously stated, these time limits rance from 70 minutes to,?40 minutes, it is not possible to predict the nature of a fire event or the actions of plant operators during an emergency. However, the staff expects that a degree of uncertainty and confusion will exist and that time delays will occur in the implementation of manual actions. To mitigate this potential problem, the licensee committed in a. letter dated February 10, 1987 to revise the-post-fire safe shutdown procedures. Upon confirmation of a fire in a fire area / zone where manual actions are required within 30 minutes, an operator will be immediately dispatched to the remote shutdown panels and stand by to begin implementing the reauired manual actions when directed.
It is the staff's judgment that dispatching an operator (s) to these areas before loss of redundant capability occurs will provide significant additional time margin to assure that the required actions will be accomplished before an unrecoverable plent condition occurs. However, by letter dated fiarch 10, 1987, the licensee notified the staff that under certain circumstances involving a fire in fire areas / zones CB-FA-?d or 2f that manual action must be taken to restore reactor coolant pump (RCP) seal cooling or trip the RCPs in less than ten minutes. The licensee still proposes that upon confirmation of a fire in these fire areas / zones that an operator be sent immediately to the remote shutdown area and stand by to take appropriate action if RCP seal cooling is lost. But the licensee is also proposing a revina fire watch for fire areas /7ones CB-FA-2d and Pf.
For reasons as discussed under exemption ?
(ventilation systems), the staff concurs that the roving fire watch will detect fires early in their formative stages allowing time to extinguish the
' fire and/or take appropriate manual actions. Therefore, the combination of a roving fire patrol watch and dispatching personnel to stand by at the remote shutdown area upon confirmation of a fire in fire areas / zones CB-FA-2d ard Pf is accept.ble to the Commission.
For those actions which must be taler beyond 30 minutes, the staff concludes that a sufficient time margin exists which provides reasonable assurance that these actions can be achieved in the time required.
On this basis, the Commission concludes that the licensee's alternate fire protection configuration provides an equivalent level of safety to that achieved by compliance with Section III.G of Appendix R.
The special circumstances of 10 CFR 50.12 apply in that application of the reculation in the particular circumstances is not necessary to achieve the underlying purpose of the rule. The underlying purpose of the rule is to accomplish safe shutdown in the event of a sinole fire and maintain the plant in a safe condition. The rule reouires fire protection for circuits and components associated with shutdown-related valves and pumps. However, certain valve and pump components can withstand the effect of a fire and still be manually operated. Sufficient time exists to allow this manual operation and maintain the plant in a safe shutdown condition. Thus, the underlying purpose of the rule is satisfied allowing manual operation of these components. Additionally, the licensee argues that providing additional protection features, as required by the regulations, would not result in a significant increase in the level of protection provided and would result in undue hardship and costs significantly in excess of those incurred by others similarly situated. These costs consist of additional engineering, procurement of materials, fabrication, and installation costs.
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Ill.G.?; exemption requested from rrovidisp fire protection for the t
heating, ventilation, and air conditioni/4 (HVAC) systen componects located in
.c or associated w'Ith the eteroency feedwater pump renm,,djasel generatur beildinc,
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,v control building, screer, water pumphouse, and dec}y(Aeat removal and nuclear service closed cycle cooling pump room.
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In Revision 7'to the FHAR and in letters to the staff dated July ??, 1986, g
s February 11 and 28, 1987, the licensee' identified a number of locations where redundant circuits'for the above referenced systems are not protected per the p
3 fire protection ' options identified in Section III.G. The licensee has stated y
d that if a fire were t damage the HVAC systems serving jhe above locations,
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sufficient time exi ts to take certain actions to prevent rcom temperatures fromreachingcrjticallevels.
In some areas, such as the intake screen and pumphouse (ISPH), the licensee had proposed to rely upon portable fans to i
i maintain acceptable room temperatures.
In other locations, such as the q
control building, the' licensee had proposed to shed non-essential loads to
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L' reduce the temperature rise. However, by letter dated February 28,19P7,
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the licensee identified'another approach to assure that recuired ventilation
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systems were maintained frde of fire damace.
For every area which contains cables / components whose damage could result in the loss of HVAC, except the ISPH, the licensee proposes to implement a fire watch patrol. The patrol will be arranced such that no area will be left unattended for more than 20 minutes, in the instrument shop, enntrol room and HP chemistry lab, the fire watch function will be performed by the personnel who normally occupy thoso areas on a contiruous basis.
In.the ISPH, the licensee will utilire portable ventilation equipment to compensate for damaged HVAC components imediately upon loss of ventilation flow, s
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The st ff's principal concern was that e fire of significant racnitude
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I, qG ilation in these locotions.
In those areas which are continuously attended i (
or where a fire watch patrol is provided, there is reasonable assurance that a fire, if one should occur, would be discovered in its formative stages.
beQre signifdcant temperature rise or smoke prepacation occurred. The I
personnel wy41d then notify the control room that a fire was in progress, which would, result in the dispatch of the plant fire brigade to the scene.
Pending arrhval of the fire brigade, these same personnel who are trained to
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usetheavakl@leportablefireextinauishers,willattempttocontrolthefire.
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Theexpectedjoutckresponsetosuchapostulatedfireissufficienttoassure thatone'?ivisionofrequiredventilationsystemswouldremainfreeoffiredamace.
The,licFesee has, stated that upon loss of ventilation in the ISPH, at least fou'h hours is available before critical room temperatures are reached.
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Thelicenseehas.tdmmittedtoimmediatelydispatchplantpersonneltorestore It is ventilation using portable equipment upon loss of normal HVAC systems.
the staff's judoment that sufficient time exists, with a conservathe margin of safety, to res' tore adequate ventilation flow rates. On the basis that portable fans taking suction from outside areas can provide sufficient ventilation and that the licensee's procedures will assure that these actions are completed on time, the staff concludes that the licensee's prorosal is k
acceptable.
J Rased on the above evaluation, the staff concludes that the licensee's alterrete fire protection configu' ration provides an eouivalent level of safety Q,s to that achieved by compliance with Section III.G of Appendix P.
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9-The underlyino purpose of the rule is to ensure that safe shutdown capability exists durtne and'after any postulated fire in'the plant.
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Protectionofsupportjngsystems,theircomponentsandcircuitsisreouiredif Ia the support is essertial for the' operability of a safe shutdown system.
For the4ISPF, sufficient time exists to allow corrective marual actions to be
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taken.
For the other HU C systems, protection can be provided by detecting fires early in their forr.ative stage and extincuishing them before they become large enough to damage both trains of important eauipment in a civen fire area /rene. Fire watches, either in the form of a continuous fire watch (either by a perstn ph'ysically in the area or via remote monitoring) or a roving patrol which is present in a fire zone / area at least once every 20 minutes, provide adequate assurance that fires in these areas will be detected early in their formative stage. The fires can be extinguished before they damage equipment necessary for the safe shutdown of the plant. Therefore, the exemption requested meets the special circumstances delineated in 10 CFP 50.1?(a)(F)(iii, in that application of the re/ation in this particular circumstance is not necessary to achieve the underlying purpose of the rule.
In addition, the licensee claims that the special circumstances of 10 CFR 50.12(a)(?)(iii) apply in tht' providing additional protection features, required by the regulations, would not result in a significant increase in the level of protection provided and would result in undue hardship and cost significantly in excess of those incurred by others similarly situated. These costs consist of engineering, procurement of materials, fabrication and installation costs.
3.
III.G.?; exemption reouested from Appendix R to the extent that it reauires that steel which is framed into or supports a fire barrier be protected to the same degree as the barrier itself.
l In its Safety Evaluation Report (SFR) of December 30,19PE, the staff described the locations in which fire-rated cable and/or fire-rated cable wraps will be used to protect one division of shutdown-related cables.
In the fellowing four areas, the licensee has not protected the supports for open i
raceways carrying the fire-rated cable or supports for the cables, conduits or trays protected by the cable wraps:
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ISPH-FZ-1 FF-FZ-1
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The staff's principal concern is that a fire of significant maonitude would cause roon temperatures to rise to a level which would cause the steel supports to lose their structural integrity. The resulting collapse of the ccnduit or cable tray could damage the circuits which must remain functieral to achieve and maintain safe shutdown conditions.
However, each of these areas is equipped with automatic fire detection and suppression systems.
If a fire occurs, the Commission's staff expects the detection systems to actuate and transmit an alarm to the control room.
Upon confirmation of a fire, the fire bricade would be dispatched to the area and would suppress the fire using available portable eouipment.
If rapid terperature rise occurred before the arrival of the brigade, the automatic l
fire suppression system would actuate to control the fire and to reduce roor l
l temperatures. This would occur well befcre the support steel would reach a temperature at which structural failure could be expected. Therefore, the absence of protection for this steel has no safety significance.
Based on the above evaluation, the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of safety to that achieved by compliance with Section Ill.G.? of Appendix R.
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The underlyino purpose uf the rule is to provide protection acainst fire danace to the structural steel supports associated with Appendix R safe shutdown cables, eouipment, and associated non-safety circuits. This protection is being accomplished by ensuring that the tenperatures within the expected zones will not rise to levels which could affect the structural steel integrity. Therefore, the exemption being requested meets the special circumstances delineated in 10 CFR 50.1?(a)(?)(ii), in that application of the regulations in this particular circumstance is not necessary to achieve the underlying purpose of the rule.
4 III.G.?; exemption requested for the chiller room in the fuel handling building (area FH-F7-6) from the requirement that an automatic fire suppression system be installed in an area where one division of shutdown systems is protected by a one-hour fire barrier and a fire detection system.
Contained in this fire area are redundant power cables (LSSA and LS58) for control center IC-ESV. These redundant power cables are protected with one-hour fire rated barriers. The area is protected by an automatic fire detection system and manual fire fighting eouipment. As described in the licensee's FHAR the fire loading in this area is minimal.
The staff's principal concern in this area was thit a fire of significant magnitude could damage the above-referenced power cables for control center TC-FSV. However, the fire leading in the area is mirimal, with combustible material dispersed throughout the area. Because of the fire detection system, the staff expects that a fire, if one should start, would be detected in its incipient staaes before a significant room temperature rise occurred. An alarm would be automatically transmitted to the control room. The fire l
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brigade would subsequently be dispatcheo, and the fire suppressed usino manual fire fightina equipment.
Pendinc arrival of the briaade, the one-hour fire-rated barrier which protects these cables will provide reasonable assurance that they would rerain undamaged. Therefore, the absence of an automatic fire suppression system has no safety significance.
Based on the above evaluation, the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of safety to that achieved by compliance with Section III.G of Appendix R.
The basic purpose of the rule is to ensure that equipment impnrtant to the safe shutdown of the plant is available in the event of a fire.
The minimum fire loadino in the area, coupled with a fire detectinn system and a one-hour fire-rated barrier, all insure that at least one of the two cables will remain undamaced in the event of a fire. The fire should be detected and extinguished early. Therefore, the exemption being requested meets the special circumstances delineated in 10 CFR 50.1?(a)(?)(ii), in that application of the regulations in this particular circumstance is not necessary to achieve the underlying purpose of the rule.
5.
Ill.G.?; exemption requested from the requirement that redundant shutdown divisions be separated by a three-hour fire-rated barrier.
Specifically, the fire-rated barrier which forms the perimeter of intermediate building area IB-FZ-8 contains two steel plate doors which are nnt fire-rated, as determined by an independent testing authority.
Each door is used for flood protection and is bolted in place. One door is located in a portion of the wall which is common to auxiliary building area AB-FZ-4.
The other is located in a wall common to fuel handling building area FH-FZ-1.
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The fire Iceding in IB-FZ-P is low. es described in FFAR. Each of the adjacent areas is protected by an area-wide eutomatic sprinkler svstem. -The three areas are Elso provided with automatic fire detection systems and marnal fire fiohtino equipment as described by the 'icensee in the FHAR.
The staff was orioinelly con 4erned that a firt of significant maanitude would cause these doors to fail, allowing fire to propagate and camage redundant shutdown-related systems. However, because of the protection provided by the automatic sprinkler systems in areas AB-F7-4 and FH-F7-), the staff concludes that room temperatures resultino frcm a fire in these locations would not reach critical levels such as to cause the doors to fail. Because of the substantial noture of the doors (as confirmed by observation durino the Appendix R audit) and their beino bolted in place, the staff concludes that smoke and hot gases would be confined to the area of fire origin until the fire was suppressed.
Similarly, the nature and quantities of combustibles in IB-FZ-8 are such as to not produce a fire of intense magnitude or duration.
The heat produced from a fire in this location would rise to the ceiling and stratify above and i
away from the doors. By the time the stratified hot cas layer would begin to envelope the doors, the plant fire brigade would have arrived to begin active fire suppression activities.
If, unoer the most conservative fire scenario, l
fire spread through the doorways, the existino automatic sprinkler systems on the other side would actuate to protect safe-shutdown systems in the adjoining l
locations from fire damace.
l Based on the above evaluation, the staff concludes that the licensee's l
alternate fire protection confiouration provides an eouivalent level of safety to that achieved by compliance with Section III.G.2 of Appendix R.
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The underlying purpose of the rule is to provide assurance that one of the redundant trains of safe shutdown equipment is free of fire damace throuoh adequate separation and protection, in order to ensure safe shutdown s'
capability during and after any postulated fire in the plant. This' assurance is being accomplished by providing area-wide automatic sprinkler coverage in fire zones AB-FZ-4 and FH-F7-1 which adjoin IB-F7-8, by providing adequate separation between the steel doors and by the low combustible loadino in IB-FZ-8.
Therefore the exemption being requested meets the special circumstances delineated in 10 CFR 50.12(a)(ii), in that application of the regulation in this particular circumstance is not necessary to achieve the underlying purpose of the rule.
In addition, the special circumstances of 10 CFR 50.l?(a)(iii) apply in that providing additional protection features.
reauired by the regulations, would not result in a significant increase in the level of protection provided and would result in undue hardship and cost significantly in excess of those incurred by others similarly situated. These costs consist of additional enoineerino, procurement of materials, fabrication and installation costs.
The Commission had previously granted exemptions to Appendix R in an Exemption dated December 30, 1986. One exemption granted concerned the lack of a fire detection system in fuel handling building area FH-FZ-?.
By letter dated February ?,1987, the licensee clarified this exemption request to include tFe fact that the existino automatic sprinkler system does not extend throughout the area. The partial sprinkler system was acknowledoed in the staff's evaluation and, therefore, this clarification does not alter the staff's conclusion that the exemption should have been granted. This condition
' conforms with the guidance issued on partial fire detection and suppression systems in Generic-letter 86-10 No specific exemption.for the partial sprinkler system in this area is therefore necessary.
In its December 30, 1986 Exemption, the staff grtrted an exemption fron the requirement to protect certain shutdown-related circuits where the licensee has stated that sufficient time exists (in excess of 30 minutes) to take manual actions to compensate for the loss of those circuits. By letter dated February ?, 1987, the licensee has aoain changed the approach to safe shutdown in a nurrber of locations. Certain valve alignments are no longer required; other valve alignments are now considered necessary; and certain recuired manual actions which had not been previously included in docketed submittals are now identified. The licensee states that these changes are within the scope of the staff's previous evaluation. On this basis, the clarifications reoarding manual valve alianments, as identified in the licensee's February ?, 1987 letter, are acceptable and should be considered to be encompassed by the previous exemption.
IV.
Accordinoly, the Commission has determined that, pursuant to 10 CFR 50.12, these exemptions are authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense ard security. The Commission further determines that special circumstances, as provided in 10 CFR 50.1?fa)(2)(ii), are present,iustifying the exemption; namely, that application of the regulation in the particular circumstances is not necessary to achieve the underlying purpose of the rule. Specifics are I
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. discussed in each exemption request; but in general, the underlying purpose of the rule is to accomplish safe shutdown in the event of a sinole fire and maintain the plant in a safe shutdnwn condition. This is accomplished by assuring that sufficient undamaged equipment is available to suppnrt safe shutdown assuming a fire within the area of concern.
In the areas for which an exemption is being reouested, passive as well as active fire protectirn features assure.that any single fire will not result in the loss of safe shutdown capability. These features include marcal actions, automatic suppression, and early detection of fires in their incipient stages. The fire protection features, in conjunction with low combustible loadings, provide a high decree of assurance that a single fire will not reeult in loss of safe shutdown capability.
In addition, the special circumstances of 10 CFR 50.1?
(a)(?)(iii) apply in thot compliance would result in costs that are significantly in excess of those contemplated when the regulation was adopted. Providing additional protection features, as would be required to meet the regulations, would not result in a significant increase.in the level of protection and would result in undue costs for additional engineering, procurement of materials, fabrication, and installation. Accordingly, the Commission hereby grants the exemptions listed in Section III above fron the requirements of 10 CFR 50, Appendix R.
Pursuant to 10 CFR 51.32, the Commission has determined that the grantinc of this Exerrption will have no significant irract on the environment (52 FF 8389 )-
This Exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION ph@lb
)DA FrankJ.MiMobia,D 'ector Division of PVR Licensing-P th Dated at Bethesda, Maryland, this 19 of M rch 1987 1
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