ML20076D434
| ML20076D434 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 05/17/1983 |
| From: | Harrington W BOSTON EDISON CO. |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| 83-130, NUDOCS 8305230450 | |
| Download: ML20076D434 (36) | |
Text
r-ED BTO N EDISON COMPANY B00 SQYLSTON STREET BOSTON. MAssACHUBETTs 02199 WILLIAM D. HARRINGTON cineen vise rasesosut aaw.
May 17,1983 BEco Ltr. #83-130 Mr. Domenic B. Vassallo, Chief Operating Reactors Branch #2 Division of Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C.
20555 License No. DPR-35 Docket No. 50-293 Appendix R Exemption Requests
References:
(A) BECo Letter dated June 25, 1982, " Boston Edison Response to Appendix R" (B) NRC Letter dated January 17, 1983, " Review of Safe Shutdown Capability Appendix R to 10 CFR Part 50, Items III.G and III.L" (C) NRC Letter dated January 31, 1983, denying BECo's requests for exemptions to Appendix R (D) BECo Letter dated March 11, 1983, "Information on 10 CFR 50 Appendix R Items III.G and III.L (E) BECo Letter dated March 11, 1983, requesting a reconsidration of exemption requests to Appendix n (F) BECo Letter dated April 14, 1983, "Long Term Program and Schedule"
Dear Sir:
N In Reference (A) BECo submitted a fire protection analysis with plans, schedules O
and exemption requests to fully meet the requirements of applicable sections of 5
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f Reference (B) approved our proposed methods of compliance regarding safe capability with a few exceptions. We responded to those exceptions in Reference (D).
Reference (C) denied all the Reference (A) technical and schedular exemption requests, and as a result, we requested re-consideration via Reference (E)..rG*vbDawgk-
?s Die Ec(O B305230450 830517 PDR ADOCK 05000293 F
CD3 TON E21:DN CIMPANY Mr. Domenic B. Vassallo, Chief May 17,1983 Page 2 On March 29, 1983 BEco representatives met with members of the staff involved in the review of fire protection for Pilgrim and agreed that BECo will re-submit certain requests for technical and schedular exemptions.
Included in this re-submittal would be information of sufficient nature to enable the staff reviewers to make a determination as to the adequacy of our requests.
Typical of such in-formation would be:
- specific dates for schedular exemptions
- specific modifications proposed for each area
- more detailed configurations of redundant safe shutdown cables and equipment identification of in-situ combustibles and other hazards in each area Additional infonnation was to be submitted as a supplement, pursuant to 10 CFR 50.48, and any new requests for exemption or re-formatted requests requesting relief in a manner other than originally proposed would be submitted pursuant to 10 CFR 50.12.
For consistency, we have kept the same exemption numbers as our original Ref-erence (A) submittal. The need for an exemption request from the requirements of fireproofing structural steel supporting 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire boundaries is still under review. Relief if necessary, will be requested in the near future. The schedular relief sought in Item #10 is requested to afford consistency which is necessary in our approach to managing the Long Term Program submitted to your office via Reference (F). All the proposed msdifications have been integrated and work will proceed during the exemption period requested.
As shown in the attached, exemption request numbers 5 (formerly numbers 5 & 6), 9 and 10, are being resubmitted pursuant to 10 CFR 50.48.
1 Exemption request numbers 7 & 8 (and associated tables) are beino re-submitted pursuant to 10 CFR 50.12.
Should you have any questions or concerns as a result of your review, please do not hesitate to contact us.
l Very truly yours, Attachments i
EXEMPTION REQUEST #5 (See Table 5.1)
Exemption Request for Fire Zone 1.30A (Torus Compartment)
Per the provisions of 10CFR50.48, Boston Edison Company requests exemption from the requirements of section IIIG.2 (b) of Appendix R for the Pilgrim Nuclear Generating Station.
Specifically, exedption is requested from the requirement to have an automatic fire suppression system and fire detection system installed in the Torus Compartment. The Torus Compartment has redundant trains of instrumentation for torus water level and torus temperature located in the same fire zone and, therefore, does not meet the specific requirements of Appendix R.
The technical bases which justify the exemptions are summarized below and the supporting fire zone data is given in Table 5.1.
This information provides reasonable assurance that the public health and safety will be protected in a fashion equivalent to that resulting from compliance with the specific requirements of Appendix R.
1.
The only redundant train of systems that are located in the Torus Compartment is the instrumentation for torus water level and torus temperature.
' orus water level is provided by four level instruments 2.
'i located in the Torus Compartment. Each instrument functions independently of the other instruments and any one instrument being functional will provide the operator with indication of torus water level. The location of these instruments and cables are shown on Figure #4.
As indicated by Figure #4 the instruments are located about 900 epart on the outside of the torus vessel.
Since any one of the four instruments will provide the operator with torus level indication, a fire would have to engulf about 3/4 of the Torus Compartment before level indication would be lost. In addition, all cables for these instruments l
are installed in conduit, thus additional protection is provided from fire.
[
3.
The existing torus water temperature indication is being modified l
to meet the requirements of NUREG 0661 and Appendix R.
As part of the modifications to meet the requirements of Appendix R, Boston Edison Company is proposing to add another means of monitoring torus l
water temperature from a location outside the Control Room. The l
location (after modifications) of the instruments that will be j
available to monitor torus water temperature is shown on Figure #4.
The instruments function independently of each other and any one temperature instrument channels will provide the operator with an l
indication of torus temperature. As shown by Figure #4, the dis-tance between the instruments at the closest point is approximately I
30 feet horizontal under the torus vessel and approximately 10 feet vertical on either side of the torus vessel.
In addition, all cables for these instruments are installed in conduit, thus additional protection is provided from fire.
l (Page l'of 2)
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.a 4.
There are no installed combustibles between the different instruments that measure torus water level and torus water temperature and the redundant equipment exceeds the 20 foot minimum separation criteria of Appendix R.
The transient combustibles loading in the Torus Compartment creates a -
maximum theoretical fire exposure of less than 4.4 minutes.
These factors coupled with the proposed modification will insure that at least one train of instrumentation will remain free of fire damage in this area.
5.
The objectives for the protection of safe shutdown capability is to insure that at least one means of achieving and maintaining safe shutdown conditions will remain available during and af ter any postulated fire in the station.
Modifications required to meet the requirements of section IIIG.2 of Appendix R would not enhance the fire protection safety of Pilgrim Station any better than the modifications proposed by Boston Edison Company for this fire zone.
The proposed modifications to the torus temperature instruments will insure that one instrument channel will remain free of fire damage for any postulated fire in the area.
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(Page 2 of 2)
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EXEMPTION REQUEST #7 Exemption Request For Fire Zones 1.9 and 1.10 (EL 23'-0" Rx Building)
Per the provisions of 10CFR50.12, Boston Edison Company requests ~
exemption from the requirements of section IIIG.2 (b) of Appendix R for
'the Pilgrim Nuclear Generating Station. Specifically, exemption is requested from the requirement to have an automatic fire supp ession system installed throughout fire zones 1.9 and 1.10 and from the requirements of having redundant trains of equipment required for safe shutdown separated by a horizontal distance of more than 20 feet with no intervening combustibles or fire hazards.
Boston Edison is proposing, as part of the modifications for these fire zones, to install sprinkler protection in the boundary area separating these fire zones as shown on figure #1. The exemption request is necessary to exempt Boston Edison Company from the reauirements to provide total area sprinkler protection for both fire zones. The horizontal separation between redundant trains required for safe shutdown is much greater than the 20 feet required by section IIIG.2 (b) of Appendix R.
However, there are cable trays in the separation area that are considered combustibles.
The technical bases which justify the exemptions are summarized below and the supporting fire zone data is given in tables 7.1 and 7.2.
This information provides reasonable assurance that the,public health and safety will be protected in a fashion equivalent to that resulting from compliance with the specific requirements of Appendix R.
1.
Fire zones 1.9 and 1.10 are part of a fire area in the Rx Building,
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EL 23'-0".
Fire zones 1.9 contains "A" train components required for safe shutdown. Fire zone 1.10 contains "B" train components required for safe shutdown. These fire zones are separated by a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> boundary along their common boundary except for an area approximately 30 feet wide on the North side of the building.
2.
Once modifications are implemented as described in tables 1.1 and 1.2, hot shutdown eqripment in fire zone 1.9 will be separated from the redundant hot shutdown equipment in fire zone 1.10 by a horizontal distance of approximately 75 feet.
Cold shut-down equipment in fire zone 1.9 will be separated from the redundant cold shutdown equipment in fire zone 1.10 by a horizontal distance of approximately 100 feet.
These distances given are the closest dimensions between cables or conponents that are part of systems required for hot or cold shutdown.
3.
The combustible loading between Fire Zones 1.9 and 1.10 is extremely low. These zones are separated by a volume that is essentially free
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of combustible materials.
(Page 1 of 2)
,e The only fixed combustible material in the separating volume is cable insulation. The insulation is either IEEE Std. 383 qualified cable or the cables have been coated with an approved fire retardant material.
There are only six trays within the separation volume. These trays are at least one foot apart. These factors will preclude a fire within any one of the six trays from interacting with the other trays and propagating across the separation volume.
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Total automatic fire suppression would not enhance the protection of safe shutdown functions provided by the present configuration and proposed modifications.
The combustible loading in fire zones 1.9 and 1.10 creates a maximum theoretical fire exposure of only minutes. The nearest safe shutdown equipment is 75 feet apart.and separated by a minimum 20 feet wide clear space. These factors co'upled with the proposed Water Spray system within the separation clear space will assure at least one train of safe shutdown equipment will remain free of fire damage in,.
this area.
4.
Automatic smoke detection exists in both fire zones which alarms in the continuously manned Control Room.
5.
The objectives for the protection of safe shutdown capability is to insure that at least one means of achieving and maintaining safe shutdown con- <4 ditions will remain available during and after any postulated fire in the station. Modifications required to meet the requirements of Section III G.2 of Appendix R would not enhance the fire protection safety of Pilgrim Station any better than the modifications proposed by Boston Edison Company for these two fire zones. The modification proposed for these two fire zones, as described in Table 1.1 and 1.2, will insure that at least one train of safe shutdown equipment will remain free of fire damage for any postulated fire in the area.
6.
Modifications required to meet the requirements of Section III G.2 of Appendix R would in fact be detrimental to overall facility safety.
i These fire zones are too large and porus to permit the installation of an effective gaseous suppression system. Additionally it is not possible to install a total area sprinkler system in either of the fire zones. There are many wide obstructions (i.e. cable trays, HVAC ducts, pipes, etc.) between l
the floor and ceiling such that ceiling leve1 sprinklers would not be able to protect anything over several feet below the ceiling. Many additional i
levels of sprinklers would be needed. With the additional sprinkler pipes and sprinklers the probability of accidental discharge is substantially increased. The water damage to safety related equipment from real or l
inadvertant actuation represents an unacceptable risk to Boston Edison Company.
i (Page 2 of 2)
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i EXEMPTION REQUEST #8 Exemption Request for Fire Zone 1.11 and 1.12 (EL 51'-0" RX Building).
Per the provisions of 10CFR50.12 Boston Edison Company requests exemption from the requirements of Section III G.2 (b) of Appendix R for the Pilgrim Nuclear Generating Station. Specifically, exemption is requerted from the requirements to have an automatic fire suppression system insta11r.d throughout fire zones 1.11 and 1.12 and from the requirements of having redundant trains of equipment required for safe shutdown separated by a horizontal distance of more than 20 feet with no intervening combustibles or fire hazards.
Boston Edison is proposing, as part of the sudf ficatiota for these fire zones, to install sprinkler protection in the boundary area separating these fire zones as shown in Figure #2. The exemption regatsi is necessary to exempt Boston Edison Company from the requirements to provide total area s-
.nkler protection for both fire zones. The horizontal separation between redund,, trains required for safe shutdown is much greater than the 20 feet reqv. ired by
- ction III G.2 (b) of l
Appendix R.
However, there are cable trays 'o the scparation area that are con-l sidered combustibles.
t The technical bases which justify the exemptions are summarized below and the supporting fire zone data is given in Tables 8.1 and 8.2.
Stis information pro-vides reasonable assurance that the public health and safety will be protected in a fashion equivalent to that resulting from compliance with the specific require-ments of Appendix R.
1.
Fire zones 1.11 and 1.12 are part of a fire area in the RX Building, EL 51'-0".
Fire zone 1.11 contains "A" train components required for safe shutdown.
Fire zone 1.12 contains "B" train components required l
for safe shutdown. Tne fire zones are separated by a three hour fire boundary except in the following areas:
(a) An area approximately 40 feet wide along the common boundary on the north side of the building, (b) An area approximately 11 feet wide along the common boundary on the south side of the building, and (c) through an open hatchway and stair-well to the elevation above these fire zones.
2.
Once modifications are implemented as described in Tables 2.1 and 2.2, hot shutdown equipment in fire zone 1.11 will be separated from the redundant hot shutdown equipment in fire zone 1.12 by a horizontal l
distance of approximately 70 feet. Cold shutdown equipment in fire zone 1.11 will be separated from the cold shutdown equipment in fire zone 1.12 by a horizontal distance of 70 feet. These distances given are the closest dimensions between cables of components that are part of systems required for hot or cold shutdowns.
3.
The combustible loading between fire zones 1.11 and 1.12 of elevation 51 ft. is extremely low.
The only fixed combustible material in the north and south separation zones of elevation of 51 ft. is cable insulation. The insulation is either IEEE Std. 383 qualified cable or the cables have been coated with an approved fire retardant material. There are only 'five cable trays in l
the north separation volume and there are three trays in the south separation volume.
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(Page 1 of 2)
a All trays are at least one foot apart in each direction. These factors will preclude a fire within any one of the five trays from interacting with the other trays and propagating across the separation volume.
The combustible loading in fire zones 1.11 or 1.12 creates a maximum theoretical fire exposure of only minutes. The nearest-safe-shutdown equipment is 70 feet apart and separated by a minimum 20 f t.
wide clear space.
These factors coupled with the propo~ sed water epray system within the separation clear space will assure at least one train of safe shutdown equipment will remain free of fire damage in this area.
4.
Automatic smoke detection exists in fire zones 1.11 and 1.12 which alarms in the continuously manned Control Room.
5.
Even though the ceilings of zones 1.11 and 1.12 do not have rated three hour boundaries, this does not present a safe shutdown problem because of the following existing conditions:
a) All penetrations in the ceilings of the two areas are thre'e hour rated except for the hatchway and stairwells.
b) The areas above these fire zones do not contain equipment or cables required for safe shutdown.
c) The areas above these fire zones are equipped with automatic smoke detection, hose stations and portable fire extinguishers.
i d) The combustible loading is low as shown in Table 2.1.
e) The hatchway and stairwell that forms the boundary violation, is separated by a horizontal distance of approximately 80 feet.
6.
The objectives for the protection of safe shutdown capabi11ty is to insure that at least one means of achieving and maintaining safe shut-down conditions will remain available during and after any postulated fire in the station. Modifications required to meet the requirements of Section III G.2 of Appendix R would not enhance the fire protection safety of Pilgrim Station any better than the modifications proposed by Boston Edison Company for these two fire zones. The modifications proposed for these two fire zones, as described in Table 2.1 and 2.2, will insure that at least one train of safe shutdown equipment will remain free of fire damage for any postulated fire in the area.
7.
Modifications required to meet the requirements of Section III G.2 of l
Appendix R would in fact be detrimental to overall facility safety.
These fire zones are too large and porus to permit the installation of an effective gaseous suppression system. The water damage to safety related equipment from real or inadvertant actuation of a sprinkler system represents an unacceptable risk to Boston Edison Company, i
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1 (Page 2 of 2) 1 l.
EKD(PTION REQUEST # 9 Boston Edison Company installed an alternate shutdown system for the Cable Spreading Room and Control Room, per the requirements of Appendix A to BTP APCSB 9.5-11, during the 1980 refueling outage.
The system was designed to provide safe shutdown capability for a fire in the Cable Spreading Room or Control Room. However, during the pafe shutdown analysis conducted for Appendix R, it became apparent that certain features of the alternate shutdown system were helpful in other fire zones other than the Cable Spreading Room or Control Room. For example, the alternate shutdown panels located in the Diesel Generator Rooms will not only isolate all Diesel Generator control cables from the Control Room and Cable Spreading Room but also isolate the same control cables from every fire zone between the Diesel Generator Room and the Cable Spreading Room or Control Room.
Once the control switch on the alternate shutdown panel is switched from the remote to the local position, the cable that the switch controls is now totally isolated from the control circuit. Therefore, the loss of the cable that has been isolated by the alternate shut-down panel has no effect on safe shutdown capability.
In some instances Boston Edison Company has proposed to implement procedures to provide operator action for a loss of cable function due to a fire. The operator action, in this case, is to isolate the afffected cable using the existing alternate shutdown panel and to control that component from the alternate shutdown panel.
Since these procedures will be implemented for fire zones other than the Cable Spreading Room or Control Room, Boston Edison Company feels that an exemption from the requirements of section IIIG.3 must be requested.
Therefore, per the provisions of 10CFR50.48, Boston Edison Company requests exemption from the requirements of section IIIG.3 of Appendix R for the Pilgrim Nuclear Generating Station.
Specifically, exemption is requested from the requirement to have a fixed suppression system installed in the area, room or zone where alternate shutdown capability is provided. This exemption is requested for the following fire zones:
Fire Zone 1.9 East side Rx Building, EL 23'-0" Fire Zone 1.10 West side Rx Building, EL 23'-0" Fire Zone 1.11 East side Rx Building, EL 51'-0" Fire Zone 1.12 West side Rx Building, EL 51'-0" Fire Zone 3.5 Vital M.G. Set Room, EL 23'-0" The technical bases which justify the exemption request are listed below.
This information provides reasonable assurance that the public health and safety is protected in a fashion equivalent to that resulting from compliance with the specific requirements of Appendix R.
1.
It is the position of Boston Edison Company that the fixed suppression requirement of section IIIG.3 was intended by the NRC to be only applicable' to areas where alternate shutdown was provided as the only means of meeting safe shutdown (Page 1 of 2)
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capability for an area as opposed to using other options or methods given in section IIIG of Appendix R.
The alternate shutdown system was installed for the Cable Spreading Room and Control Room and these areas are in full compliance with the requirements of section IIIG.3 of Appendix R.
A new.
automatic Halon fire suppression system is being instal 1 d 9
in the Cable Spreading Room to replace the existing CO2 system and; therefore, this area will be in compliance with section IIIG.3 as soon as the Halon system is installed and declared operational. Boston Edison Company has an approved exemption request from the requirement to have a fixed l
suppression system in the Control Room and, therefore, is in compliance in this area.
2.
Even though certain features of the existing alternate shutdown system are being utilized on a limited basis for the fire zones where exemption is requested, it is not the primary means of achieving safe shutdown capability for these fire zones.
3.
Once the affected cable is isolated from the fire zone using the alternate shutdown panel, fire damage to that cable has no effect on safe shutdown capability.
4.
Automatic smoke detection, which alarms in the continuously manned Control Room, exists in all the fire zones where exemption from the requirements of section IIIG.3 is requested.
5.
The objective for the protection of safe shutdown capability is to insure that at least one means of achieving and maintaining safe shutdown conditions will remain available during and af ter any postulated fire in the station. Modifications to install l
fixed suppression in the fire zones where exemption is requested I
would not enhance fire protection safety at Pilgrim Station.
Use of the alternate shutdown sy. tem for these fire zones will insure that at least one train of safe shutdown equipment will remain free of fire damage for any postulated fire in any of the above fire zones. The addition of a fixed suppression system in these fire zones would not in any way improve the capability to achieve safe shutdown.
6.
The above fire zones are not conducive to the installation of a gaseous fire suppression system and the installation of a fixed water suppression system would in fact be detrimental to overall facility safety because of water damage to safety related equipment from real or inadvertent actuation.
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(Page 2 of 2) 1
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EXEMPTION REQUEST #10 Boston Edison Company herein requests relief from the schedular requirements of 10 CFR 50.48, which currently requires implementation of Appendix R modifications before startup after the earliest of the following events commencing 180 days or more after NRC approval:
- 1) The first refueling outage
- 2) Another planned outage that lasts for at least 60 days
- 3) An unplanned outage that lasts for a least 120 days l
Our final completion date for all modifications would be prior to restart from Refuel Outage #7, tentatively scheduled to commence in November 1985.
New Date: December 1985 Justification:
Section 8.0 of our Reference (A) submittal provided justification and compensatory measures to be taken when our modification schedules showed June 1987 as the final completion date.
These measures, in turn will be provided to reflect the revised completion date of December 1985.
As depicted in our detailed Long Term Program Schedule, work will proceed in an ongoing fashion with measur-able increments or milestones.
Prior to the issuance of Appendix R, Pilgrim Station had been reviewed against the criteria of Appendix A to the Branch Technical Position (BTP) 9.5-1 and a Fire Protection Safety Evaluation was issued on December 21, 1978 as Amendment
- 35 to the License.
The safety evaluation required that modifications be made to plant physical features and systems, and that administrative controls be estab-11shed accordingly.
Further evaluation and information exchanges ensued on remaining open items which have since been resolved.
In addition, our instrumen-tation and procedures in effecting safe shutdown independent of the cable spread-ing and control rooms were found acceptable by your staff and put in place.
This capability will be available during the period of exemption.
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We believe that with the compensatory measures referenced above and the ongoing incremental Fire Protection improvements depicted in our Long Term Program Schedule, Reference (F), there is no undue risk to the health and safety of the public involved with the granting of relief to the schedular requirements of 10 CFR 50.48 until prior to restart from refuel outage #7.
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Page 1 of I s
mL TABLE 5.1 FIRE ZONE 1:30A: REACTOR BUILDING EL (-)
17'-6", TORUS COMPARTMENT A.
AREA CONSTRUCTION:
1.
Walls - See Figure #4.
Walls are 36" concrete with 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> penetrations with the exception of doorways into the quad-rants which are not fire doors and the penetrations into the quadrants which have not been upgraded to a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rating.
2.
Floor - 96" concrete slab on soil.
3.
Ceiling - 24" concrete slab; 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated with 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> penet ration seals.
4.
Ceiling height - 38'-6".
5.
Area Volume - The area volume less the torus suppression chamber is approximately 235,740 cubic feet.
6.
Congestion - Area is essentially free of floor congestion.
General access for manual suppression is adequate.
B.
SAFE SHUTDOWN EQUIPMENT 1.
Af ter the proposed modifications are implemented for this fire zone, only the "B" train of systers required for safe shutown will remain in fire zone 1.30A.
All "A" t rain cables and components that are required to be operable for safe shutdown will not be located in this fire zone.
The exception to this is torus water level and torus temperature instrumentation which is the subject of exemption request
- 5.
For a fire in fire zone 1.30A, safe shutdown will be accom-plished with the "A" train of systems.
Figure #4 shows the location of instrumentation for torus water level and torus
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water temperature in the Torus Compartment. As stated in exemption #5, one instrument should be available to measure each varible in order to achieve safe shutdown.
C.
COMBUSTIBLES This item provides the technical justification for not providing any additional fire protection in the Torus Compartment.
The combustible materials in the Torus Compartmenb fire zone 1.30A, is primarily fi e retardant treated staging.
The fire logding and J
the theoretical fire exposure are described in the table below:
(Page 1 of 3)
Fire Quantity Continuity of Equivslint Fire R;tordent Zone C: bustib1:a C;nbustiblso Theorcticci Protection Type / Weight Through Fire Exposure Type Ibs.
Fire Funutes Zone No. 1.30A Wood Staging /
No 4.4 Yes-Wood staging
. Reactor 8200*3 has been painted with fire retardant coating Bldg.
Ele'v. (-)17 f t Cable /24 No IEEE 383 - I tray j
Cable There ar9 two approaches to analyze fire spread potentials. The "theo-retical" method mathematically compares specific plant fire loads to a Standard Time-Temperature fire. The " realistic" I method evaluates the physical array of specific combustibles and the possibility of fire propagation within the array.
THEDRETICAL ANALYSIS BECo used the theoretical approach to identify the Standard Fire Ex-posure for comparison purposes and general understanding on the " order of magnitude of the worst case fire in this area ". Any fires with a Standard exposure under 30 minutes are in the lowest severity category.
This fire zone has a Standard Fire Exposure of less than five minutes.
BECo believes that any further use of the theoretical approach is un-warranted since this method is heavily depended on defining a Design Basis Fire (DBD and the correlation between a DBF and real fire has not been satisfactorily established. More importantly, BECo postulates this is unnecessary because the realistic approach is adequate to obtain l
an appropriate level of fire protection.
l REALISTIC ANALYSIS i
f The realistic approach identifies that all potential paths for fire spread through this fire zone.
For this area, there is only one path as it is one open area. These paths have been utilized in the completion of the realistic analysis below.
Conductive heat transfer and direct flame impir.gement are not possible across these paths since there is no continuity of combustible materials in any of these paths (e.g. ve rtical or horteontal).
l Radiant heat transfer can only be a factor in fire spread when there is a j
st raigh t, unobstructed, i.e. "line of sight", path between the fire and the exposed material. It is not possible to spread fire by radiant energy transEe r in this area. The Torus is in between the transient fire I
load (i.e. stagbad and the redundant SSE.
1.
See Appendix A for a more detailed description of the theoretical and l
realistic analysis methods.
2.
Reprinted from Table 1-1, Fire Protection System Review APCSB9.5-1.
3.
This is fire retardacc ted wood on temporary staging. The staging l
encircles the exterior c. the Torus. The wood staging is also encap-f sulated with a material with fire retardant capabilities.
(Page 2 of 3)
es e
Convective heat transfer is the one method of fire spread that is remotely realistic for Pilgrim Station.
If a fire in this area could produce enough heat to raise the ambient air temperature in the entire Torus Compartment to the auto-ignition point of cable insulation, redundant channels of instrumentation could be damaged.
However, there is not a sufficient fire load in the Torus Compartment or any adjacent fire zone (i.e. 1.1, 1.7, 1.5, or 1.6) to raise the ambient temperature in this area to the required temperature.
D.
FIRE PROTECTION EXISTING 1.
Fire detection systems: None 2.
Fire extinguishing systems: None 3.
Hose stations / extinguishers: There are no portable extinguishers or hose reels in the Torus Compart-ment, however there is one hose reel and portable extinguisher in each quadrant adjacent to the Torus Com-partment that will reach all areas in the Torus Compartment.
4.
Radiant heatshield: None 5.
Propagation retardants: Cables are coated with flamemastic or qualified to IEEE-383.
E.
PROPOSED MODIFICATIONS Modifications proposed for fire zone 1.30A will insure that one train of safe shutdown equipment will remain free of fire damage for any post related fire in the area.
Modifications for the Torus Compartment (fire zone 1.30A) are as follows:
(a) The torus water temperature instrumentation is being modified as stated in Exemption Request #5 and as shown on Figure #4.
(b) The power and control cable for the "A & B" diesel generator fuel oil transfer pumps are being re-routed out of the Torus Compartment.
(Page 3 of 3)
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TABLE 7.1 j
FIRE ZONE 1.9: REACTOR BUILDING ELEVATION 23'-0", EAST SIDE AREA DATA A.
AREA CONSTRUCTION 1.
Walls See Figure il 27" concrete wall, plus 6" pre-cast panel; 3-hour North rated with 3-hour penctration seals.
(column Line-P) i l
South - 42" concrete wall; 3-hour rated with 3-hour rated penetration seals.
(column Line-H) 33" concrete wall; 3-hour rated with 3-hour rated East penetration seals.
(column Line-17)
West
- Bounded by (a) 42" concrete steam tunnel shield wall.
Three hour rating is not required because the Steam tunnel is not a redundant area.
(b) 60" concrete drywell shield wall.
(c) The unenclosed portion of l
the boundary is shared with fire zones 1.10 at column line 11.
L 2.
Floor - 24" concrete slab, three hour fire rated with three hour rated penetration seals with the exception of open stairwells to fire zone 1.8 and 1.1.
These two fire zones are not redundant to fire zone 1.9.
3.
Ceiling 12" concrete slab; three hour rated with three hour rated penetration seals with the exception of an open stairwell to fire zone 1.11 which is not a redundant area to fire zone 1.9.
4.
Ceiling height - 27 feet.
5.
Area volume Approximately 220,000 cubic feet.
j 6.
Ventilation - See Figure #1 for directional arrows showing i
ventilation flow.
7.
Congestion Area is essentially free of floor congestion.
General access for manual suppression is good.
t I
(Page 1 of 7)
f I, v
e B.
SAFE SHUTDOWN EQUIPMENT After the proposed modifications are implemented for this fire zone, only the "A" train of systems required for safe shutdown will remain in fire zone 1.9.
All "B" train cables and components that are re-quired to be operable for safe shutdown will not be located in this fire zone.
For a fire in fire zone 1.9, all "A" train components are assumed lost, and safe shutdown will be accomplished with the "B" train of systems.
The opposite is true for fire zone 1.10 where all "B" train components are assumed lost, and safe shutdown will be accomplished with the "A" train of systems. Figure #1 shows the components and cables located in fire zone 1.9 that are required to be operable for a fire in fire zone 1.10.
Listed below are the systems that will be used for safe shut-down if a fire occurs in fire zone 1.10.
The components or cables are listed if they appear in fire zone 1.9.
Figure #1 shows the location of the components and/or cables that are listed.
"A" TRAIN COMPONENTS / CABLES LOCATED IN SYSTEMS FIRE ZONE 1.9.
Automatic Alternate shutdown panel and control Depressurization cables.
System Core Spray System MCC B17 which feeds power to core spray valves. Alternate shutdown panel for core spray.
Power and control cables for the core spray system.
RHR System in the MCC B18 and B20 which feeds power to the shutdown cooling mode RHR valves. Alternate shutdown panel for RHR.
Power and contrr~ cables for-RHR system.
Rx water level and Rx None pressure Torus temperature Instrument cables for torus temperature.
Torus water icvel.
Instrument cables for torus water level.
C.
COMBUSTIBLES This item provides the technical justification for considering the space between Fire Zones 1.9 and 1.10 " free of fixed combustible material."
(Page 2 of 7)
\\,.
1 The 20 feet separation space between redundant safe shutdown equipment (SSE) contain six (6) horizontal cable trays.
(See Figure #1). The separation zone is described below: -
Separation Quantity Continuity Area of Equivalent Fire Zona Combustibles of Separation Theoretical Retardant Between Total Combustibles Zone Fire Exposure Protection %
3 Redundant lbs/ft -lbs.
Through sq. ft.
Minutes Type SSE Separation Zone Reactor Building 19.9 -- 388 Yes 900 0.4 IEEE 383-3 trays /60%
Elev. 23 ft.
non IEEE 383 Cable Coated Between with fire colunas Retardant 3 trays /607, 9.1 to 11 Material End M.7 to P 1
The theoretical equivalent fire exposure of the cable within this Separation Zone is only 0.4 minutes. This is extremely low.
l Realistica11y, the combination of fire retardant coating or the inherent fire retardant properties of IEEE 383 qualified cable and the large physical separation between the trays will prevent a fire that originates within one of these trays from generating sufficient heat to propagate a fire across the six trays in the prospective Separation Zone. An intense or large exposure fire might be able to propagate a fire across the prospective Separation Zone. However, there are no other installed combustible materials in the zone to provide the exposure fire.
Moreover, Administrative Controls were designed to limit transient combustible material on Elev. 23 feet of the Reactor Building to a maximum of 10 gallons of Class II and III liquids (i.e each) and one gallon of Class I liquids.2 Combustible loading of this magnitude, or even several orders of ma'gnitude large'r, will not totally fill che 20 foot wide Separation Zone. Additionally, since the cable trays are 11 feet above the floor, the transient loads will not be able to impinge on the entire length of the tray, 1 See Appendix A for a more detailed description of the theoretical and realistic analysis methods.
2 Flammable / combustible liquids are required to be in approved containers.
(Page 3 of 7)
r
-i s
l BECo concludes that neither the limited installed cc:bustible materials or potential transient materials would propogate a fire across the 20 foot fire Separation Zone. This zone can be considered
" free of intervening combustibles as required in section IIIG.2 (b).
C.2 This item provides the technical justification for the proposed fire protection modifications.
The combustible materials installed in Fire Zone 1.9 and 1.10 are primarily cable insulation. The fire loading and the theoreticall fire exposure are described in the table 2 below:
Fire Quantity of Continuity of Equivalentl Fire Retardant Zone Combustibles Combustibles Theoretical Protection Type-Weight through Fire Exposure Type Fire Zone Minutes No. 1.9 Cable-16,731 No 29.5 IEEE 383 70%
Ratctor Building NonIEEE 30%
Elev. 23 ft.
383 Cable East Col.
Coated with No. 11 Fire Retar-dant Material No. 1.10 Cable -14,078 No 22.8 IEEE 383 70%
Reactor Trainsient Cable Building Combustible -
Elev. 23 ft.
1036 NonIEEE 383 30%
West of Col.
Cable Coated No. 11 with Fire Retardant
- 3 Material There are two approaches to analyze fire spread potentials. The
" theoretical"I method mathematically compares specific plant fire l
loads to a Standard Time-Temperature fire. The " realistic" l l
method evaluates the physical array of specific combustibles and the possibility of fire propagation within the array.
THEORETICAL ANALYSIS BECo used the theoretical approach to identify the Standard Fire Exposure for comparison purposes and general understanding of the
" order of magnitude of the worst case fire in this area. Any fires with a Standard exposure under 30 minutes are in the lowest severity category. Fire Zone 1.9 and 1.10 have Standard Fire Exposures 29.5 and 22.8 minutes respectively.
(Page 4 of 7)
BECo believes that any further use of the theoretical approach is unwarranted since this method is heavily depended on defining a Design Basis Fire (DBF), and the correlation between a DBF and real fire has not been satisfactorily established. More importantly.
BECo postulates this is unnecessary because the realistic approach is adequate to obtain an appropriate level of fire protection.
REALISTIC ANALYSIS The realistic approach identifies that there are two potential paths for fire spread between zones 1.9 and 1.10.
First, the fire could spread horizontally across the floor.
Secondly, the fire could spread to a higher or lower elevation (e.g. 23 ft., 74 or 91) through a vertical opening and then back to the 23 ft. elevation through another vertical opening. These paths have been utilized in the completion of the realistic analysis below.
Conductive heat transfer and direct flame impingement are not possible across these paths since there is no continuity combustible materials in any of these paths (e.g. vertical or horizontal).
Radiant heat transfer can only be a factor in fire spread when there is a straight, unobstructed, i.e. "line of sight", path between the fire and the exposed material. There is either a floor or the Primary Contain-ment between the combustible materials in fire zones 1.9 and 1.10.
This eliminates the "line of sight" and will realistically prevent fire spread by radiant energy transfer.
Convective heat transfer is the one method of fire spread that is remotely realistic for Pilgrim Station.
If a fire in the fire zone 1.9 (or 1.10) produced enough heat to raise the ambient air temperature on the entire 23 foot elevation to the auto-ignition point of cable insulation, the fire could spread from fire zone 1.9 to 1.10.
BECo has conservatively assumed that there is a sufficient fire exposure in zone 1.9 (or 1.10) to accomplish the required ambient temperature.
BECo has proposed to prevent the horizontal migration of the ambient temperature profile by installing a Water Spray System within the 20 ft. Separation Zones (See Item C.1) between fire zone 1.9 and 1.10.
This is the only protective system necessary.
l BECo has not proposed any protection for the vertical openings in the j
Reactor Building floors. This is not necessary since convective heat transfer cannot occur downward until the entire volume at the higher elevation (s) has been heated. Hence, the exposure fire in fire zone 1.9 (or 1.10) would have to heat the ambient atmosphere in the Reactor Building from 51 ft. to 134 ft. to the " higher" ambient temperature before it would migrate back down into fire zone 1.9 (1.10).
The fire loads an elevation 51 ft. (or any higher elevation in the Reactor Building) are not capable of producing a fire of this magnitude.
Therefore, this is not realistic and special protection is not necessary for vertical penetration / (e.g. stairs or hatch).
(Page 5 of 7)
1.
See Appendix A for a more detailed description of the theoretical and realistic analysis methods.
2.
Reprinted from Table 1-1 Fire Protection System Review APCSB
~
9.5-1.
3.
The equivalent Theoretical Fire Exposure for the Reactor Building elevations 74 ft. (fire zone 1.14), 91 ft. (Fire Zone 1.16) and 117 ft. (Fire Zone 1.24) are 11, 1.8, 7.8 and 12 minutes respect-ively. See Table 1-1 from BECo Fire Protection System Review APCSB 9.5-1.
i D.
FIRE PROTECTION EXISTING 1.
Fire Detection systems: 32 Photoelectric smoke detectors 11 Ionization smoke detectors 2.
Fire extinguishing systems: None 3.
Hose stations / extinguishers: 2 hose reels 1 portable extinguisher 4.
Radiant heat shield: None 5.
Propagation retardants:
Cables are coated with flamemastic or qualified to IEEE-383.
E.
PROPOSED MODIFICATIONS Modification proposed for fire zone 1.9 will insure that one train of safe shutdown equipment will remain free of fire damage for any postulated fire in the area. The proposed modifications are of two types and together provide a defense in depth concept for fire protection as intended by the requirements of Section IIIG of Appendix R.
l The first type of modification involves relocating, from fire zone l
1.9, cables and equipment for the "B" train of systems required for l
safe shutdown. After these modifications are complete, fire zone 1.9 will only contain cables and components for the "A" train of systems required for safe shutdown. Some "B" train cables will re-main in the fire zone, however, the loss of these cables is acceptable since operator action will provide the same function that the cable provided. The "B" train cables will be relocated from fire zone 1.9 by rerouting them in a ductline around the outside perimeter of the plant that leaves the control building and enters the fire zone containing the components for the "B" train of systems required for shutdown. This ductline is being added as part of the modifications to meet the requirements of Appendix R.
One component for the "B" train of systems is currently located in fire zone 1.9 and will be relocated to the area where the "B" train components are located.
(Page 6 of 7)
v.
2 The second type of modification involves providing sprinkler protection in the boundary area that separates fire zone 1.9 from its redundant counterpart, fire zone 1.10.
These two fire zones are separated by a three hour boundary along their coesmon-border except for an area approximately 30 feet long on the north side of the area.
The sprinkler protection is provided to prevent a fire from propagating across the boundary area between redundant fire zones.
4 I
l l
l l
l i
i l
(Page 7 of 7)
9 TABLE 7.2 FIRE ZONE 1.10: REACTOR BUILDING ELEVATION 23'-0", WEST SIDE AREA DATA A.
AREA CONSTRUCTION 1.
Walls - See Figure #1 North - 27" concrete wall, plus 6" pre-cast concrete panel; 3-hour rated, with 3-hour penetration seals. (column Line-P)
South - 42" concrete wall; 3-hour rated with 3-hour rated penetration seals (column Line-H)
West 33" concrete wall; 3-hour rated with 3-hour rated penetration seals (column Line-5)
East - Partial enclosure; bounded by 42" concrete steam tunnel shield wall (column Line-10), 60" (circum-ferential, column Line-10 to column Line-ll) both 3-hour rated walls. The unenclosed portion of the boundary is shared with fire zone 1.9 at column Line-11.
2.
Floor - 24" concrete slab; 3-hour rated with 3-hour rated penetration seals with the exception of open stairwells to fire zones 1.7 and 1.2 which are not redundant areas to fire zone 1.10.
3.
Ceiling -
12" concrete slab; 3-hour rated with 3-hour rated penetration seals with the exception of an open stairwell, and hatchway to fire zone 1.12 which is not a redundant area to fire zone 1.10.
4.
Ceiling Height 22 feet 5.
Area Volume - Approximately 195,500 cubic feet.
l 6.
Ventilation - See Figure #1 for directional arrows showing ventilation flow.
7.
Congestion
- Area is essentially free of floor congestion.
General access for manual suppression is good.
B.
SAFE SHUTDOWN EQUIPMENT 1.
After the proposed modifications are implemented for this fire zone, only the "B" train of systems required for safe shutdown will remain in fire zone 1.10.
ALL "A" train cables and components that are required to be operable for safe shutdown will not be located in this fire zone.
(Page 1 of 3)
For a fire in fire zone 1.10, all "B" train components are assumed lost, and safe shutdown will be accomplished with the "A" train of systems. The opposite is true for fire zone 1.9 where all "A" train components are assumed ~ lost, and safe shutdown will be accomplished with the "B" train of systems. Figure #1 shows the components and cables located in fire zone 1.10 that are required to be operable for a fire in fire zone 1.9.
Listed below are the systems that will be used for safe shutdown if a fire occurs in fire zor.e 1.9.
The components or cables are listed if they appear in fire zone 1.10.
Figure #1 shows the location of the com-ponents and/or cables that are listed.
"B" TRAIN COMPONENTS / CABLES LOCATED IN SYSTEMS FIRE ZONE 1.10 Automatic Alternate shutdown panel and control Depressurization cables. MCC D8 which feeds power to the System ADS system.
Core spray system MCC B18 which feeds power to core spray valves. Alternate shutdown panel for core spray. Power and control cables for core spray system.
RHR system in the MCC B18 which feeds power to RHR shutdown cooling mode valves. Alternate shutdown panel for RHR.
Power and control cables for RER system.
Rx water level and None Rx pressure Torus temperature Alternate shutdown panel for monitoring torus temperature.
Torus water LVL Alternate shutdown panel for monitoring torus water level.
(Page 2 of 3)
C.
COMBUSTIBLES See Section (c) of Table 7.la D.
FIRE PROTECTION EXISTING 1.' Fire detection systems: 37 Photoelectric smoke detectors g
7 Ionization smoke detectors 2.
Fire extinguishing systems: None 3.
Rose stations / extinguishers: 2 Hose Reels 1 Portable Extinguisher 4.
Radiant heat shield:
None 5.
Propagation retardants: Cables are coated with flamemastic or qualified to IEEE-383.
E.
PROPOSED MODIFICATIONS i
Modification proposed for fire zone 1.10 will insure that one train of safe shutdown equipment will remain free of fire damage for any postulated fire in the area. The proposed modifications are of two types and together provide a defense in depth concept for fire protection as intended by the require-ments of Section III G of Appendix R.
{
l The first type of modification involves relocating, from fire zone 1.10, cables and equipment for.the "A" train of systems l
required for safe shutdown. After these modifications are complete, fire zone 1.10 will only contain cables and components for the "B" train of systems required for safe shutdown.
Some "A" train cables will remain in the fire zone, however, the loss of these cables is acceptable since operator action will provide the same function that the cable provided. The "A" train cables will be relocated from fire zone 1.10 by rerouting them in a ductline around the outside perimeter of the plant that leaves the control building and enters the fire zone containing the components for the "A" train of systems required for shutdown.
This ductline is being added as part of the modifications to meet the requirements of Appendix R.
The second type of modification involves providing sprinkler protection in the boundary area that separates fire zone 1.10 l
from its redundant counter part, fire zone 1.9..These two fire zones are separated by a three hour boundary along their common border except for an area approximately 30 feet long on the north side of the area. The sprinkler protection is provided to prevent a fire from propagating across the boundary area between redundant fire zones.
l (Page 3 of 3)
- ~ _. - - -.,.. _ -.,
TABLE 8.1 FIRE ZONE 1.11: REACTOR BUILDING ELEVATION 51'-0", EAST SIDE AREA DATA A.
AREA CONSTRUCTION 1.
Walls - See Figure #2
~
North - 24" concrete wall, plus 6" pre-cast concrete panel; 3-hour rated with 3-hour penetration seals.
(column Line-P)
South - 21" concrete wall, plus 6" pre-cast concrete panel; 3-hour rated with 3-hour penetration seals.
(column Line-J)
East
- 30" concrete wall, plus 6" pre-cast concrete panel; 3-hour rated with 3-hour penetration seals.
(column Line-17)
West - Partial enclosure bounded by the 60" concrete drywell shield wall (circumferential); 3-hour rated with
~3-hour penetration seals. The unenclosed portion of the boundary is shared with fire zone 1.12 at column Line-11.
2.
Floor - 12" concrete slab; 3-hour rated with 3-hour rated penetration seals with the exception of an open stairwell to fire zone 1.9 which is not a redundant area to fire zone 1.11.
[
3.
Ceiling - 12" concrete slab; 3-hour rated with 3-hour rated penetration seals with the exception of an open stairwell to fire zone 1.14 which does not contain equipr int required for safe shutdown.
4.
Ceiling height - 22'-0" 5.
Area volume - Approximately 135,950 cubic feet.
6.
Ventilation - See Figure #2 for directional arrows showing ventilation flow.
7.
Congestion - Area is essentially free of floor congestion.
l General access for manual suppression is good.
B.
SAFE SHUTDOWN EQUIPMENT (1.11) 1.
Af ter the proposed modifications are implemented for this fire zone, only the "A" train of systems required for safe shutdown will remain in fire zone 1.11.
All "B" train cables I
(Page 1 of 7)
and components that are required to be operable for safe shutdown will not be located in this fire zone.
For a fire in fire zone 1.11, all "A" train components are assumed lost, and safe shutdown will be accomplished with the "B" train of systems. The opposite is true for fire zone 1.12 where all "B" train components are assumed lost, and safe shutdown will be accomplished with the "A" train of systems.
Figure #2 shows the components and cables located in fire zone 1.11 that are required to be operable for a fire in fire zone 1.12.
Listed below are the systems that will be used for safe shutdown if a fire occurs in fire zone 1.12.
Figure #2 shows the location of the components and/or cables that are listed.
"A" m IN COMPONENTS / CABLES LOCATED SYSTEMS IN FIRE ZONE 1.11 Automatic Depressurization NONE system RHR system in the LPCI and Valve MD-1001-26A & Cables shutdown cooling Valve MD-1001-23A & Cables mode Instruments for RX water level Instrument Rack C2205 and Cables.
and Rx vessel pressure l
l (Page 2 of 7) i
,m
f
'C.
COMBUSTIBLES C.1 This item provides the technical justification for considering the space between fire zones 1.11 and 1.12 " free of fixed com-bustible material".
The 20 ft. separation space on the north side of the Reactor Building between redundant Safe Shutdown Equipment (SSE) contain five (5) horizo".tal cable trays and the south side contain three (see Figure #2). The separation zones are described below:
Continuity Szparation of Zone Quantity Combustible Area of Equivalent Between Combustible Through Separation Theoretical Redundant Total Separation Zone Fire Exposure Fire Retardant 3
SSE lbs/ft -lbs.
Zone sq. ft.
Minuter Protection Reictor 16.3 - 326 Yes 1,140 1.6 IEEE 383 - 2 trays Bui2?.ing Northside non-IEEE 383
- Elav. 51 ft.
Cable Coated with Fire
- Bztween Retardant - 3 trays columns Material 9.1 to 11 and M.7 to P Reac to r 6.6 -- 133 Yes 260 2.0 IEEE 383 - 2 trays l
Building Cable Southside j
- Elev. 51. ft.
non-IEEE 383 l
Cable Coated
- Between with Fire columns Retardant - 1 tray l
10-13 and Material l
J to K l
. = -
i l
l (Page 3 of 7)
a The theoreticall equivalent fire exposure of the cable with this Separation Zone is only 1.6 to 2.0 minutes. This is extremely low. Realistically,1 the combination of fire retardant coating or the inherent fire retardant properties of IEEE 383 qualified cable and the physical separation between the trays will prevent a fire that originates within one of these, trays from, generating sufficient heat to propagate a fire across the other trays in the respective Separation Zone. An intense or large exposure
~
fire might be able to propagate a fire across the respective Separation Zone. However, there are no other installed combustible materials in either zone to provide the exposure fire.
Moreover, Administrative Controls were designed to limit transient combustible material on Elev. 51 f t. of the Reactor Building to a maximum of 10 gallons of Class II and III Liquids (i.e. each) and one gallon of Class I Liquids 2, Combustible loading of this magnitude, or even several orders of magnitude larger, will not totally fill the 20 f t, wide Separation Zone. Additionally, since the cable trays are 11 ft. above the floor, the transient loads will not be able to impinge on the entire length of the tray.
BECo concludes that neither the limited installed combustible materials or potential transient materials would propagate a fire across either the north or south 20 f t.
fire Separation Zone an elevation of 51 f t.
These zones can be considered
" free of intervening combustibles as required in Section III G.2 (b).
C.2 This item provides the technical justification for the proposed fire protection modifications.
The combustible materials installed in fire zone 1.11 and 1.12 l
are primarily cable insulation. The fire loading and the l
theoreticall fire exposure are described in the table 2 below:
Continuity of Combustibles Equivalent Quantity of through Theoretical Fire Retardant Fire Combustibles Fire Fire Exposure Protection Zone Type --Weight Zone Minutes Type l
l No. 1.12 Cable-1870 No 7.8 IEEE 383 70%
Reactor Transient Cable Building Combus tibles -
Elev. 51 ft.
130 non-IEEE 30%
West Col.
l 383 C,able No. 11 Coated with Fire Retardant material 1 See Appendix A for a more detailed description of the theoretical and realistic analysis methods.
i l
2 Flammable / combustible liquids are required to be in approved containers.
I (page 4 of 7)
Continuity of Combustibles Equivalent Quantity of through Theoretical Fire Retardant Fire Combustibles Fire Fire Exposure Protection Zon,e Type -Weight Zone Minutes Type No. 1.11 Cable-3065 No 11 IEEE.383 70%
R*ze to r Cable Building Elsv. 51. ft.
non-IEEE 383 30%
East of Col.
Cable Coated No.11 with Fire Retardant material There are two approaches to analyze fire spread potentials. The
" theoretical"I method mathematically compares specific plant fire loads to a Standard Time-Temperature fire. The " realistic"I method evaluates the physical array of specific combustibles and the possibility of fire propagation within the array.
THEORETICAL ANALYSIS BECo used the theoretical approach to identify the Standard Fire Exposure for comparison purposes and general understanding on the " order of magnitude of the worst case fire in this area.
Any fires with a Standard exposure under 30 minutes are in the lowest severity category. Fire zone 1.11 and 1.12 have Standard Fire Exposures 11 and 8 minutes respectively."
l BECo believes that any further use of the theoretical approach is unwarranted since this method is heavily depended on defining a Design Basis Fire (DBF), and the correlation between a DBF and real fire has not been satisfactorily established. More importantly, BECo postulates this is unnecessary because the realistic approach is adequate to obtain an appropriate level of fire protection.
t REALISTIC ANALYSIS I
The realistic approach identifies that there are two potential paths for fire spread between Zones 1.11 and 1.12.
First, the fire could spread horizontally across the floor. Secondly, the fire could spread to a higher or lower elevation (e.g. 23 ft.,
74 or 91) through a vertical opening and then back to the 51 ft. elevation through another vertical opening.
These paths have been utilized in the completion of the realistic analysis below.
Conductive heat transfer and direct flame impingement are not possible across these paths since there is no continuity combustible materials in any of these paths (e.g. vertical or horizontal).
(Page 5 of 7)
Radiant heat transfer can only be a factor in fire spread when there is straight, unobstructed, i.e. "line of sight", path between the fire and the exposed material. There is either a floor or the Primary Containment between the combustible materials in Fire Zones 1.11 and 1.12.
This eliminates the "line of sight" and will realistically prevent fire spread by radiant energy transfer.
~
Convective heat transfer is the one method of fire spread that is remotely realistic for Pilgrim Station. If a fire in the Fire Zone 1.11 (or 1.12) produced enough heat to raise the ambient air temperature on the entire 51 ft. elevation to the auto-ignition point of cable insulation, the fire could spread from Fire Zone 1.12 to 1.11.
BECo has conservatively assumed that there is a sufficient fire exposure in Zone 1.11 (or 1.12) to accomplish the required ambient temperature. BECo has proposed to prevent the horizontal migration of the ambient temperature profile by installing a Water Spray System within the 20 f t.
Separation Zones (See Item C.1) between Fire Zone 1.11 and 1.12.
This is the only protective system necessary.
BECo has not proposed any protection for the vertical openings in the Reactor Building floors. This is not necessary since convective heat transfer cannot occur downward until the entire volume at the higher elevation (s) has been heated. Hence, the exposure fire in Fire Zone 1.11 (or 1.12) would have to heat the ambient atmosphere in the Reactor Building from 74 f t.
to 134 f t.
to the " higher" ambient temperature before it would migrate back down into Fire Zone 1.12 (or 1.11).
The fire loads on elevation 51 ft. (or on any higher elevation in the Reactor Building) are not capable of producing a fire of this magnitude.
Therefore, this is not realistic and special protection is not necessary for vertical penetrations (e.g. stairs or hatch).
l 1 See Appendix A for a more detailed description of the theoretical l
and realistic analysis methods.
2 Reprinted from Table I-1, Fire Protection System Review APCSB9.5-1.
3 The equivalent Theoretical Fire Exposure for the Reactor Building l
elevations 74 ft.
(Fire Zone 1.14), 91 f t. (Fire Zone 1.16) and 117 ft. (Fire Zone 1.24) are 1.8, 7.8 and 12 minutes respectively.
See Table I-1 from BECo Fire Protection System Review APCSB9.5-1.
l l
(Page 6 of 7) s-
\\
l 1
D.
FIRE PROTECTION EXISTING 1.
Fire Detection Systems:
14 Photoelectric Smoke Detectors 3 Ionization Smoke Detectors -
1 2.
Fire Extinguishing Systems: None l
~
3.
Hose Stations / Extinguishers:
1 Hose Reel l
2 Portable Extinguishers 4.
Radiant Heat Shield: None 5.
Propagation Retardants: Cables are coated with flamemastic or qualified to IEEE-383.
E.
PROPOSED MODIFICATIONS Modifications proposed for fire zone 1.11 will insure that one train of safe shutdown equipment will remain free of fire damage for any postulated fire in the area. The proposed modifications are of two types and together provide a defense in depth concept for fire protection as intended by the requirements of section IIIG of Appendix R.
The first type of modification involves relocating from fire zone 1.11 cables for the "B" train of systems required for safe shutdown. After these modifications are complete, fire zone 1.11 vill only contain cables and components for the "A" train of systems required for safe shutdown. A few "B" train cables will remain in the fire zone, however, the loss of these cables is acceptable since operator action will provide the same function that the cable provided.
The "B" train cables will be relocated from fire zone 1.11 by rerouting them in a ductline around the outside perimeter of the Plant that leaves the Control Building and enters the fire zone containing the components for the "B" train of systems required for shutdown. This ductline is being added as part of the modifications to meet the requirements of Appendix R.
The second type of modification involves providing sprinkler protection in the boundary area that separates fire zone 1.11 from its redundant counterpart, fire zone 1.12 as shown on Figure #2.
(Page 7 of 7)
a 0
TABLE 8.2 FIRE ZONE 1.12: REACTOR BUILDING ELEVATION 51'-0", WEST SIDE AREA DATA A.
AREA CONSTRUCTION 1.
Walls - See Figure #2 North - 24" concrete wall, plus 6" pre-cast concrete panel; 3-hour rated with 3-hour penetration seals.
(column Line-P)
South - 21" concrete wall, plus 6" pre-cast concrete panel; 3-hour rated with 3-hour penetration seals.
(column Line-J)
East - Partial enclosure bounded by the 60" concrete drywell shield wall; (circumferential) 3-hour rated with 3-hour penetration seals. The unenclosed portion of the boundary is shared with fire zone 1.11 at column Line-II.
West - Filled masonary block wall 12" thick.
(at column Line-7, bounded by column Line P & K) 24" concrete wall, plus 6" pre-cast concrete panel.
(at column Line-5, bounded by column Lines-J &K) 3-hour rated with 3-hour rated penetration seals.
i 2.
Floor - 12" concrete slab; 3-hour rated with 3-hour rated penetration seals with the exception of an ooen stairwell and hatchway to fire zone 1.10 which is not a redundant area to fire zone 1.12.
3.
Ceiling - 12" concrete slab; 3-hour rated with 3-hour rated penetration seals with the exception of an ooen stairwell and hatchway to the 74'-0" elevation l
which does not contain equipment required for safe shutdown.
4.
Ceiling height - 22'-3" (maximum) l 5.
Are4 volume - Approximately 87,840 cubic feet.
6.
Ventilation - See Figure #2 for directional arrows showing ventilation flow.
7.
Congestion - Area is essentially free of floor congestion.
General access for manual suppression is good.
(Page 1 of 3)
B.
SAFE SHUTDOWN EQUIPMENT Af ter the proposed modifications are implemented for this fire zone, only the "B" train of systems required for safe shut-down will remain in fire zone 1.12.
All "A" train cab,les and components that are required to be operable for safe shutdown will not be located in this fire zone.
~
For a fire in fire zone 1.12, all "B" train components are assumed lost, and safe shutdown will be accomplished with the "A" train of systems. The opposite is true for fire zone 1.11 where all "A" train components are assumed lost, and safe shutdown will be accomplished with the "B" train of systems.
Figure #2 shows the components and cables located in fire zone 1.12 that are required to be operable for a fire in fire zone 1.11.
Listed below are the systems that will be used for safe shutdown if a fire occurs in fire zone 1.11.
The components or cables are listed if they appear in fire zone 1.12.
Figure #2 shows the location of the components and/or cables that are listed.
"B" TRAIN COMPONENTS / CABLES LOCATED SYSTEMS IN FIRE ZONE 1.12 Automatic Depressurization NONE System i
RHR system in the LPCI and NONE l
mode l
Instruments for Rx water level Instrunent Rack C2206 A & B and Cables and Rx vessel pressure C.
COMBUSTIBLES See section (c) of Table 8.1.
D.
FIRE PROTECTION EXISTING 1.
Fire Detection Systems :
10 Photoelectric Smoke Detectors 3 Ionization Smoke Detectors 2.
Fire Extinguishing Systems:
None 3.
Hose Stations / Extinguishers:
2 Hose Reels 2 Portable Extinguishers (Page 2 of 3)
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1 4.
Radiant Heat Shield: None 5.
Propagation Retardants: Cables are coated with flamemastic or qualified to IEEE-383.
E.
PROPOSED MODIFICATIONS Modifications proposed for fire zone 1.12 will insure that one train of safe shutdown equipment will remain free of fire damage for any postulated fire in the area. The proposed modifications are of two types and together provide a defense in depth concept for fire protection as intended by the requirements of section IIIG of Appendix R.
The first type of modifcation involves rerouting cables that are for shutdown components in fire zone 1.12.
Fire zone 1.12 contain components for the "B" train of systems required for safe shutdown.
The cables will be rerouted from fire zones that contain components for the "A" train of systems required for safe shutdown.
The cables will be rerouted by a duct line that leaves the Control Building and enters the fire zone containing the components for the "B" train of systems required for shutdown. This duct line is being added as part of the modifications to meet the requirements of Appendix R.
Th. eecond type of modification involves providing sprinkler protection, as shown on Figure #2, in the boundary area that fire separates fire zone 1.12 from its redundant counterpart, zone 1.11.
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APPENDIX A
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THEORETICAL AND REALISTIC FIRE ANALYSIS There are two approaches to analyze fire and its development - the " theoretical" and " realistic" methods.
The theoretical methods models the chemistry and physics of fire. This method manifests itself through laboratory testing and identifies standard or minimum developmental parameters for fire. These parameters are useful for comparison purposes and selection of materials, components or plant configurations during design. For example, the theoretical method converts all combustible material within c specific volume of the plant to its " equivalent" calorimetric heating value. The heat loads are totaled for all materials in that plant volume.
Finally, the theoretical method assumes all the heat is released in a duration of time equivalent to the Standard ASTM E-119 Fire Test. The resultant is a theoretical maximum equivalent Standard Fire Severity.
(The Tables in the exemption requests illustrate that the Standard Fire Severity is extremely low for each of the applicable fire zones.
This analogy defines a specific air temperature profile over a standard time duration. This is very conservative because it does not consider the differences in the rate of combustion of the various materials. However, by comparing these factors for specific materials, an order of magnitude on fire severities can be estimated. The longer the
" equivalent standard fire" the higher the expected severity for that combustible load. This information is also used in the realistic method where equivalent fire severity is used to determine the required fire resistance rating of building materials.
The realistic method evaluates the actual physical configuration between combustible material, non-combustible materials and building construction while applying the guidance gained from the theoretical method.
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.2 In this method, the experience obtained from plant inspection and fire investigation temper the theoretical predictions and estimates. The basic thermodynamics for fire development and spread from the foundatidh for the realistic approach.
Fire can spread by one of the mechanisms.
They are:
1.
Conductive heat transfer 2.
Radiant heat energy transfer 3.
Convective heat transfer Realistically, combustible materials ignite only after they absorb a specific amount of heat energy. The required energy can be transferred from the burning material to the -adjacent material directly, i.e. items 1 and 2, or indirectly (e.g. burning material to air to adjacent material), i.e. item 3.
Fire spread involving direct contact is much faster than through the convective process. From this simple knowledge, the realistic method makes an even simpler, conservative presumption. When combustible materials are present, and their
[
physical configuration appear conducive to one of the heat transfer mechanisms, some fire prevention or extinguishment must be provided.
l Both methods have many limitations as fire protection is an emerging science with many answers yet to be reached. However, proper application of these methods will lead to solid treatment and protection for fire risk. BECo has and will continue to update their application of these methods to provide the highest level of fire protection for life safety and property conservation.
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