ML19309A872
| ML19309A872 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 03/24/1980 |
| From: | Randy Hall BROOKHAVEN NATIONAL LABORATORY |
| To: | Ferguson R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8004010446 | |
| Download: ML19309A872 (7) | |
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$.jd BROOKHAVEN NATIONAL 1.ABORATORY fl ~l l '
ASSOCIATED UNIVERSITIES, INC.
id iJ su Upton, New York 11973 Department of Nuclect Energy (516) 345 2144 March 24, 1980 Mr. Robert L. Ferguson Plant Systems Branch U.S. fluclear Regulatory Commission Washington, D.C.
20555 RE: Yankee Rowe, Fire Protection Review, Items 3.1.5 and 3.1.12(d).
Dear Bob:
Enclosed are items 3.1.5, Water Suppression Systems, and 3.1.12(d),
Control of Comtastibles (d - exposed structural steel D.G. room).
We do not have sufficient information on items 3.1.1, 3.1.6, 3.1.7, 3.1.12(c), 3.2.1, or 3.2.3.
Item 3.2.3 is not assigned to us.
This completes the present Brookhaven flational Laboratory input to Yankee Rowe.
Sincerely yours,
,, p,/ !
,-4/
N$WW Ro'.,ert E. Hall, Group Leader Reactor Engineering Analysis REH:EAM:sd enclosure cc.:
L. Derderian D. Eisenhut W. Kato wo/ enc, M. Levine E. MacDougall V. Panciera E. Sylvester Aoot L
.s ll1 8004010 't 4C.
- F
YANKEE R0WE Fire Protection Review Item 3.1.5(b) - Water Suppression Diesel Generator Rooms Item 3.1.5, part (b) of the Yankee Rowe SER indicates the licensee's proposal to provide a manually operated dry pipe sprinkler system to protect each diesel generator room.
In their letter dated July 2,1979, the licensee indicated their intention to provide a manually operated dry pipe sprinkler system in each of the three diesel generator rooms. The system will consist of 212*F sprinkler heads designed to provide a density of 0.3 gpm/sq.ft. They also indicated that each system would be manually operated from a valve station outside each room, and that a strainer would be installed in the common supply to the three systems.
In their letter dated October 9,1979,'the licensee indicated that the manual actuation valve for each system would consist of a gate valve accessible to the operator by way of a reach rod.
On November 13, 1979, the licensee transmitted a letter which further indi-cated that the systems are designed and installed to meet the requirements of NFPA 13.
Included with this letter were Jrn 'ns which indicated the sprink-ler systems in the diesel generator roens would cosist of four sprinkler heads. However, the drawings are not :n scale and do not indicate pipe sizes.
Based on a review cf the design criterta and conceptual drawings submitted by the licensee, the p oposed manually oparated sprinkler system is considered acceptable contingent on the submittal of final design drawings for review and the use of 1/4 turn fire protection valves as the system control valves if the reach rod will he utilized to operate these valves.
Item 3.1.5(c) - Water Suppression Hydrogen Seal Oil Unit and Transforme-Oil Cooler Item 3.1.5 of the Yankee Rowe SER, idantified here as 3.1.5(c), indicates the licensee's proposal to provide automatic actuation for the deluge system which protects the hydrogen seal oil unit and transfomer oil cooler.
Appendix A to BTP 9.5-1, Section F.8 " Turbine Lubrication and Central Oil Storage and Use Areas," states the f9llowing:
"A blank fire wall having a mintaum resistance rating of three hours should separate all areas containing safety related systems and equipment from the turbine oil system. When a blank wall is not present, open head deluge protection should be provided for the turbine oil hazards and auto-matic open head water curtain protection should be provided for wa!1 open-ings."
Appendix R to 10 CFR, Part 50, states in Section II.A.2.e that " Automatic sup-pressiun systems shall be provided to control large fire hazads or to protect redundant systems or components important to safe shutdown."
Additionally, Section E.3(a) of Appendix A states:
"Each automatic sprinkler system and manual hose station standpipe should have an independent connection to the plant underground watermain. Head-ers fed from each end are permitted inside buildings to supply multiple sprinkler and standpipe systems.
When provided, such headers are con-sidered an extension of the yard main system. The header arrangement should be such that no single failure can impair both the primary and backup fire protection systems."
The suppression system preser;tly installed to protect the hydrogen seal oil unit and transformer oil cooler consists of open head sprinklers which are part of the Zone 1 manual suppression system for the turbine building.
In their letter dated July 2,1979, the licensee indicated that the deluge sys-tem protecting the hydrogen seal oil unit and the transformer oil cooler will be supplied by an automatically operating deluge valve which will open on actuation of any two detectors of a detection system which will be installed in the area. They also stated that a manual trip will be provided, and that alarms indicating system operation will be provided.
On October 9,1979, Yankee Rowe transmitted a letter which indicated that the hydrogen seal oil unit and transfonner oil cooler deluge system will be de-leted from the turbine building suppression system (Zone 1) and incorporated as part of a special hazards system which will also include five building col-umn sprays.
In their letter dated November 13, 1979, the licensee stated that the deluge system is designed and installed in accordance with the criteria of NFPA 15.
With this letter, they also transmitted preliminary drawings showing the proposed changes to this deluge system. These drawings are unclear in that they indicate that the special hazards system indicated above will be fed from the bulk feed main of the Zone 1 turbine building system and also from a " dis-charge inlet station" and that, in addition to the column sprays, it will in-clude sprinklers over the boiler feed pumps and air compressors in the area below the switchgear room. The discharge inlet station is supplied from the same single connection to the plant fire loop main as are the Zone 1, 2, and 3 sprinklers for the turbine building. The drawings are conceptual drawings only, since no pipe sizes or control valve details are shown.
Based on a review of the licensee's submittals, including preliminary draw-ings, the licensee's proposed method to provide an automatic deluge system to protect the hydrogen seal oil unit and turbine oil cooler is not acceptable.
The preliminary drawings indicate that the special hazards system provided for the column sprays and the deluge system will be cross-connected to the Zone 1 turbine building sprinkler system and that the supply feeder from the main plant fire system looped header to the turbine building sprinkler systems will also be used to supply the special hazards system and standpipe hose stations.
Thus a single failure in the fire protection system could impair all fire protection water to the turbine building.
in order for the licensee to meet their commitment to provide an automatic de-loge system for the hydrogen seal oil unit and turbine oil cooler and also comply with Section E.3 (a) of Appendix A, the special hazards system should be supplied from a separate connection to the looped plant fire protection header. Valves should be provided to cssure that a single failure will not impair both the special hazards system and the turbine building sprinkler sys-tems.
In addition, there should be no cross-connection between the special hazards system and the Zone 1 turbine building sprinkler system. We recommend that the licensee should submit revised plans to NRC for review and approval prior to implementation of any modifications.
Item 3.1.5(d) - Water Suppression Turbine Building Section 3.1.5(d) of the SER states:
"The turbine building sprinkler system will be modified and extended to provide automatic sprinkler coverage with a 0.3 gpm/sq. ft. density over the most hydraulically remote 3000 ft2 under the turbine operating floor. The area of sprinkler protection will extend to fire hazards under the switchgear room floor. The feed to the sprinkler system will be provided which is independent of the feeds to hose stations and auto-matic suppression systems protecting the same area. Exposed I beams in the control room wall facing the turbine building will be protected by a waterspray system."
An unmitigated fire in the turbine building could threaten the structural capability of the building which supports the enclosures for the switchgear room and control room.
Fires in the areas of cable routings would cause the loss of essential service functions.
Fixed fire suppression systems are presently provided in three specific areas.
Zone 1 is a dry pipe system with both fusible link and open sprinkler heads protecting the west end of the turbine building. The open heads provide pro-tection for the hydrogen seal oil unit and main transformer oil coolers and piping. Zone 2 is a dry pipe system with both fusible link and open sprinkler heads protecting the east end of the turbine building. The open heads provide protection for the turbine lube oil reservoir, related oil piping and equip-ment. The deluge valves for these two systems are operable from three dif-ferent locations, including the control room.
Zone 3 is a wet pipe sprinkler system which protects the lube oil storage room and a portion of the machine shop. Hose stations are located throughout the turbine building. All sources of fire suppression water for the turbine build;ng are supplied from a single l
connection to the plant looped fire protection water header.
The combined open and closed head manually actuated systems could cause exces-sive water demands. A fire between two zones would necessitate the actuation of both systems with the open heads spraying water in areas where water sup-pression may not be required. Similar conditions could be expected if a fire were to develop in an unprotected area. The resultant opening of excessive numbers of sprinkler heads could seve-ely deplete the water supply capability of the systems, and the fire may not be extinguished.
additionally, Section E.3(a) of Appendix A (previously quoted) must be met or deviations justified.
In their letter dated July 2,1979, (previously referred to) Yankee Rowe indicated that the turbine building sprinkler systems will be modified to closed head, wet pipe systems, and that they would be extended to provide cov-erage in the area under the switchgear room which contains the steam generator feed pumps and the air compressors. They also indicated that the systems protecting the special hazards (including the transfomer oil coolers) will be supplied from a different source, and that area sprinklers would also provide a coverage over the special hazards. Their intent to provide closed-head spray nozzles to protect the turbine building columns adjacent to the control room /switchgear room area was also stated.
In their letter dated October 9,1979, the licensee described further the ad-ditions and modifications they propose for the turbine building suppression system. They again indicated that the deluge system for the hydrogen seal oil unit and transformer oil cooler will be disconnected from the Zone 1 turbine building suppression system and incorporated into a new special hazards sys-tem. The water deluge for the turbine oil reservoir will be deleted from the Zone 2 turbine building suppression system, and the hazard will be protected by a foam system.
Zone 1 was redesigned as a wet pipe system to provide a spray density of 0.3 gpm/sq. ft. over the most hydraulically remote 3000 sq. f t. under the turbine operating floor, and some pipe sections will be replaced to accommodate the revised flow. An addition to Zone 1 will include installing one sprinkler over each air compressor and two sprinklers over each boiler feed pump in the area under the switchgear room floor; the system in this area is designed for a spray density of 0.3 gpm/sq. ft.
Zone 2 has been recalculated to provide a spray density of 0.3 gpm/sq.ft., and sme pipe will be replaced as in Zone 1.
This system is also being changed from a dry pipe, manual system to a wet pipe automatic system.
The steel columns will be protected by closed sprinkler heads installed in ac-cordance with NFPA 15, Section 4-4.3.3(b),
" Vertical structural steel members shall be protected by nozzles spaced not greater than ten feet on centers (preferably on alternate sides) and of such size and arrangement as to dis-charge not less than 0.25 gpm per square foot over the wetted area." The sprinklers will be placed on alternate sides of the column, with a total of six sprinklers protecting each column from elevation 1029'-8" to 1070'-8".
The sprays for columns G-8 through G-12 will be fed from the special hazard system protecting the hydrogen seal oil unit and transformer oil cooler, but will be on the supply side of the deluge valve which controls the supply to the seal oil unit / transformer cooler area. The sprays for column G-7 will be direct from the inlet / discharge station.
In their letter of November 13, 1979, Yankee Rowe stated that the suppression systems comply with NFPA 13 and NFPA 15 requirements, as applicable, and sub-mitted conceptual drawings of these modifications. These drawings indicate certain changes in pipe sizes to both the Zone 1 and Zone 2 systems in the I
i
turbine building and also indicate that the extension of the system to protect the area under the switchgear room floor provides only for sprinklers above each compressor or pump as indicated above. A cross connection between the special hazards system and the Zone 1 system is also indicated on the draw-ings. The drawings also indicate that all fire protection water for the tur-bine building (sprinkler systems, special hazard systems, and standpipe hose stations) will continue to be supplied through a single 8" connection to the looped fire protection supply header.
Based on an analysis of Yankee Rowe's submittals, including the preliminary drawings, the licensee's proposed method of modifying and extending the tur-bine building sprinkler system is not acceptable. The proposed modifications do not provide for complete sprinkler protection for all areas below the tur-bine operating floor and do not provide adequate isolation of the various sys-tems (sprinklers, special hazards, and standpipe hose) from each other.
In order for the licensee to adequately meet their commitment to modify and extend the turbine building sprinkler systems the following changes should be made to their proposal:
1.
The special hazards system (column watersprays and deluge system for the hydrogen seal oil unit and turbine oil cooler) should be isolated from the turbine building sprinkler systems by removing the cross-connection to the Zone 1 sprinkler system and by providing an indepen-dent connection to the looped fire protection supply header, with ade-quate valves installed to isolate the connection from the sprinkler system connection.
2.
The standpipe hose stations should be supplied from an independent connection to the looped fire protection supply header and valves added so that a single failure of the fire protection system will not impair both sprinklers and standpipe hose stations.
3.
The turbine building sprinkler systems should be expanded to provide complete area protection for the area under the turbine building oper-ating floor; sprinkler heads located only over the compressors and feed pumps do not provide total area protection for the area under the switchgear room floor.
We recommend that the staff request the licensee to submit revised preliminary plans to the NRC for review and approval prior to implementation of any pro-posed modifications.
Item 3.1.5(e) - Water Suppression Auxiliary Boiler Room item 3.1.5 of the Yankee Rowe SER, identified here as 3.1.5(e), indicated the licensee's proposal to provide an automatic sprinkler system to protect the auxiliary boiler room.
The auxiliary boiler room contains the heating boiler, the steam driven emer-gency feedwater pump, and the fuel supply lines to the diesel generators. An unmitigated fuel oil spill fire could result in the loss of the emergency feedwater pump and seriously threaten the integrity of the fire barriers
between adjacent areas. Without an automatic supression system, the fire pro-tection for this area is inadequate due to the potential for a large fuel oil fire. As it states in Section II A.2.e of Appendix R to 10 CFR Part 50,
" Automatic suppression systems shall be provided to control large fire hazards..."
In their letter dated July 2,1979, Yankee Rowe indicated that an automatic sprinkler system with an average spray density of 0.3 gpm/sq. ft. will be provided in the auxiliary boiler room.
In their letter dated October 9,1979, the licensee stated that this system will be a two tier system because of the room configuration, and it will be supplied from the inlet discharge station located outside the auxiliary heating boiler room.
Conceptual drawings of the system and a commitment to a design which complies with NFPA 13 were submitted with the licensee's letter dated November 11, 1979. These drawings do not indicate pipe sizes, nor do they indicate the two tier design indicated in the licensee's October 9,1979 letter.
However, event without these criteria, the system is acceptable based on the licensee's density commitments on their compliance to NFPA 13. This accept-ance is concurrent with the requirement in SER items 3.1.5(c) and (d) that the special hazard and standpipe and hose systems for the turbine building are supplied by an independent connection to the looped fire protection header and are not dependent on the sprinkler system supply connection. We recommend that any modifications to this system other than that required for the separation of the supply connections be submitted to NRC for review and approval.
Item 3.1.12(d) - Control of Combustibles Item 3.1.12 of the Yankee Rowe SER, identified here as 3.1.12(d), indicated the licensee's proposal to either protect the exposed structural steel in the diesel generator rooms or to change the proposed manually operated dry pipe sprinkler system to an automatic actuated system.
The present design of the diesel generator building roof consists of a metal deck supported on large, unprotected steel I beams. At the diesel generator rooms, thesa I beams pass through the walls which separate the three diesel generators. Collapse of these I beams as the result of a fire in any one of the diesel generator rooms could result in wall damage and subsequent loss of all three diesel generators. Because of the oil fire hazard present, a man-ually actuated suppression system may not be operated prior to failure of the steel beams.
In their letter uated October 9,1979, Yankee Rowe stated that the exposed structural steel in the diesel generator rooms will be protected with a one hour rated fire retardant coating. The licensee did not indicate which coat-ing they will use, or how the fire rating of the coating was obtained.
l We recommend that the staff accept the proposed one hour rated protection for the structural steel in the diesel generator rooms contingent on the l
licensee's submittal of a fire retardant coating design which meets the provisions of ASTM E-119 for one hour fire resistance for structural steel beams.