ML19309B023
| ML19309B023 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 06/19/1978 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8004020500 | |
| Download: ML19309B023 (3) | |
Text
O h Ir k REGULATORY INFORMATION DISTRIBUTION GYSTEM (RIDS)
DISTRIBUTION FOR INCOMING MATERIAL 50-312 REC: REID R W ORG: MATTIMOE J J DOCDATE: 06/19/7S NRC SACRAMENTO MUN UTIL DIST DATE RCVD: 06/22/78 DOCTYPE: LETTER NOTARIZED: NO COPIES RECEIVED LTR 1 ENCL 0
SUBJECT:
FURNISHING LIST OF ITEMS WISHED TO DE DEVIATED FROM SPECIFIC REQUIREMENTS 6 PROPOSE AN ALTERNATE MEANS OF ACCOMPLISHING THF INTENT OF MODIFICATIONS.
PUR90 ANT TO LIC AMEND NO 19. SUBMITTED 02/28/73 INCLUDING REQUIREMENTS FOR MODIFICATION TO UPGRADE THE PL PLar4T NAME: RANCHO SECO (SMUD)
REVIEWER INITI AL:
XJM DISTRIBUTOR INITIAL: 94,,.
00***************
DISTRIBUTION OF THIS MATCRIAL IS AS FOLLOWS ******************
FIRE PROTECTION INFORMATION (AFTER ISSUANCE OF OL'i.
(DISTRIBUTION CODE AGO6)
FOR ACTION:
BR ruter ORBM4 BC**LTR ONLY(3)
INTERNAL:
F_a FILF+' TR ONLY(1)
NRC PDR**LTR ONLY(1)
TR ONLY(2)
OELD**LTR ONLY(1)
AUXILIARY SYS BR**LTR ONLY(2)
AD FOR GYS & PROJ**LTR ONLY(1)
PLANT SYSTEMS BR**LTR ONLY(5)
WAMBACH**LTR ONL Y(1)
R.
MURANKA**LTR ONLY(1)
HANAUER**LTR ONLY(1)
EXTERNAL:
LPDR'S SACRAMENTO, CA**LTR ONLY(1)
REGION V**LTR ONLY(1)
TIC **LTR ONLY(1)
NSIC**LTR ONLY(1)
ACRS CAT B**LTR ONLY(16)
C-DISTRIBUTION:
LTR 39 ENCL 0 CONTROL NBR:
-70170.?_5 SIZE: 2P cocOGC*****************************
THE END
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.s sMun fEW as ce ale CDPV SACRAMENTO */UNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, California 95813; (916) 452-3211 June 19,1978 Director of Nuclear Reactor Regulation Attention:
Mr. Robert W. Reid, Chief Operating Reactors, Branch 4 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Docket No. 50-312 Ranch'o Seco Nuclear Generating Station, Unit No.1
Dear Mr. Reid:
License Amendment No.19 transritted to the District on February 28, 1978 included specific requirements for modification to the Rancho Seco Nuclear Generating Station, Unit No.1 to upgrade the plant fire protection systems.
For the following listed items, we wish to deviate from the specific requirements and propose an alternate means of accomplishing the intent of the modifications:
1.
Paragraph 3.1.l(6) of Amendment No.19 states " Replace the non-Undemriters Laboratory labeled ventilation duct dampers in' east wall of the computer room with fire dampers."
This subject is also discussed in Paragraphs 4.9.2 and 5.1.6(6). This modification was proposed in the District's Fire Hazards Analysis submitted to the NRC on August 1,1977.
The existing dampers are low leakage dampers and this feature must be retained in order to provide adequate isolation of the control room during a radiological release.
Dampers having a U.L. lable that also meets the isolation criteria leakage rates are not available.
We therefore request that Item 3.1.l(6) be revised as follows:
" Add Undemriter's Laboratory Labeled ventilation duct dampers in the east wall of the computer room."
Paragraph 5.1.6(6) should also be revised as follows:
" Add Undemriter's Laboratory Labeled ventilation duct dampers in the east wall of the computer room. The fire danpers will be fusable link actuated and will serve to prevent the propogation of fire past the wall and also protect the normal dampers from external fires.
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R. W. Reid June 19,1978 The normal dampers will be automatically actuated by means of ionization detectors in adjacent areas to prevent the propogation of smoke and low level heat into the control room."
2.
Paragraphs 3.1.l(8), 4.3.3, and 5.1.6(8) allow installation of Halon 1211 portable fire extinguishers in the control room. NFPA 128, Paragraph 1210, states "The discharge of Halon 1211 may create hazards to personnel such as dizziness, impaired coordination, reduced visibility and exposure to toxic decomposition products." Since the control room must be continually manned by alert operators, we request that the type of Halon referenced in all of the above paragraphs be changed from "Halon 1211" to "Halon 1301."
As indicated by the discussion in Paragraph A-1201 of the Appendix to NFPA 12A and in Paragraph A-1200 of the Appendix to NFPA 128, Halon 1301 is significantly less toxic than Halon 1211.
Since they have nearly equal fire suppression characteristics, the revision will not affect overall fire f.ighting capabilities.
I 3.
Paragraphs 3.1.23(1), 3.1.24(1), and 5.9.6 require the District to install six (6) inches of fire resistant concrete on the east wall of the diesel generator rooms to provide a three hour rating.
The District proposes to install two (2) inches of Carboline Company Pyrocrete 102 magnesium oxychloride to each side of these walls to achieve the necessary rating.
One (1) two inch la 1r is rated to provide three hour resistance for a fir. on the side to which it is applied.
It is felt that the two (2) two inch layers will provide resistance significantly in excess of the three hour rating requi red.
Therefore, the District requests that references to six (6) inches of fire resistant concrete in the above cited paragraphs be revised to two (2) two inch layers of magnesium oxychloride.
Since time is of the essence in meeting the required completion schedule, we request that you respond to this letter by July 15, 1978.
Sincerely yours, sL.
)AssistantGeneralManager
. Mattimoe and Chief Engineer
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