ML19275A264
| ML19275A264 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/28/1979 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Miller W NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| NUDOCS 7910030429 | |
| Download: ML19275A264 (1) | |
Text
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7, i SMUD SACRAMENTO MUNICIPAL UTILITY DitTRICT C 6201 S Stret.t. Box l' 30, Sacramento, California 95813; (916) 452-J211 A
September 28, 1979 U.
S. Nuclear Regulatory Com.nission ATTN:
William O. Miller, Chief License Fee Management Branch Office of Administration Washington, D.
C.
Dear Mr. Miller:
Please refer to the attached copy of our letter addressed to Mr. Robert W.
Reid dated August 31, 1979 where-in the District requests that approval be given to chances in paragraphs 3.1. 8 (1) and 5.3.6, and to :he design criteria to implement the changes to the Fire Protsction Safety Evaluation Report attached to License Amerdment No. 19 dated February 23, 1978.
ha are enclosing our check in t.e amount of $4,000 in payment of the fee required for NRC's eview of the above mentioned letter.
The enclosed license fee is paid under protest since a lawsuit is on file in the Uni *.ed States Court of Appeal for the 5th Circuit (Mississippi Power & Light Co., et al. vs.
United States Nuclear Regulatory Commission, et al.
Civ. No.
78-1565) to obtain review of the validity of those rules.
Sincerely,
/u d.,. b hut 1 GM
/' hn J. Mattimoe o
Assistant Ger.eral Manager and Chief Engineer
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August 31, 1974 Director of l'uclear Reactor Regulation Attention: Mr. Robert H. Reid, Chie-f Operating Reactors, Branch Plo. 4 U. S. Nuclear Pegulatory Comission Washington, D. C.
20555 Docket No. 50-312 Rancho Seco iluelcar Generating Station, Unit flo.1
Dear fir. Reid:
Paragraph 3.8.1(1) of the Fire Protection Safety Evaluation Report attached to License Arend: rent No.19, dated February 23, 1973 describes the following n'odification for the west 480 volt switchgear room:
" Install a thermal barrier around conduits containing Channel 5 cables associated with: hich pressure injection systems; auxiliary feedwater system, rec'ote control f r decay heat systen valves; channels B, C and D control rod drive trip systen circuits; and channels B and C safety features actuation."
The District requests that the paragraph be rewritten to state the following:
" Reroute or install themal barriers over all channel 8, C and D conduits whose failure could prevent a safe shutdown and cooldown."
The first paragraph of Paraoraph 5.3.5, also discussed the east 480 volt switchgear room, and states the followino:
"The ifcensee proposes to provide thermal barriers over the entire length of all channel A, C and D conduits containing cables for safe shutdown to prevent their loss for the desion basis fire in the event the CO2 system should fail (see ioction 4.10)."
The District requests that this paragraph be changed to state:
"For the east 480 volt switchnear rcom, the licensee proposes that all channel B, C and D conduits, whose failure could prevent a safe shutdcwn and/or cooldown, in the event of a Cosion Basis Fire be rerouted or protected with a thermal barrier."
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,,..cie "For the west 480 switchgaar roo, the licensee proposes that all channel A, C,. nd 3 conduits whcle failure could e
prevent a safe shutdown and/or cooldown in the event of a Design ~bsis Fire be rc: outed or protected with a themal barrier.'
The District is requesting the above changes since the existinq paragraph:
1.
Pequires themal barriers around conduits that are nnt required for safe shutdown and cooldown.
2.
oes not pemit the rerouting of circuits required for safe shutdown and cooldown out of a fire area.
3.
Does not pertain to the west 400 volt switchgear room, l.icensino Avendncnt 'lo.19 requested that design details on the proposed rodification in paragranh 3.3.l(1) be submitted to the 'IPC to assure that the desion is acceptable. The desion details are listed below.
They are based on the NRC accepting the District's proposed rewording of the paragraph.
Desian Details for frmicmpntina ParanranS 3.1.8(1)
'The west 400 volt switancar roon is a channel "A" room and a Design Casis Fire in this room will cause the loss of channel "A" functions required for safe shutdcwn and cocidown. The preposed nodifications are desinned to protect channel "B" "C" and/or "D" circuits required for safe shutdown and cooldown. This will be accocplished by one or more of the following r.ethod :
1.
Insulatinq conduits that are routed through the reon that contains circuits required for safe shutdown and cooldown.
The cenduits will be insulated with two inches of fiberfrax hot bc3.r1 manufactured by the Carberundun Comneny.
The insulation will be jacketed with.016 inch stainless steel sheets held in place with stainless steel hands.
A description of the Qualifyinq test performed on the insulation systen is in the District's fire Stop Test Pece,rt test set-up one, conduit insulation fire test two. This test report was subtitted to the *:9C on t' arch 1, 1978.
2.
-eroutino channel B, C, er 0 circuits throuch other fire areas. Vhen this is done, a fire hazard analysis will be perfomed for all the new areas that the circuit is routed throuqh to ensure a safe shutdcun and cooldown is still possible with a Design Pasis Fire in the arca with the new circuit.
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Reroute the control drive trip circuits that interconnect the Reactor Protection System and control rod drive system in separate conduits. These circuits fall safe, i.e.
cause a reactor trip on an open, short on ground. However, they are routed in conduits with other circuits and a possible failure mode existed where the trip circuits could interact with other circuits in the condait and fail in a non-safe direction. Rerouting the circuit in a separate conduit correct this problem.
The proposed modification to paragraph 3.1.8(1) and the criteria used to implement the modifications will ensure that a design basis fire in west 480 volt switchgear room will not prevent safe shutdown and cool-down.
To complete the modification described in paragraph 3.1.8(1) by i'
the end of the 1979-1980 refueling as required by Table 3.1 of the Safety Evaluation Report attached to Amendment '
19..the District requests HRC comments and/or approval on the change 11. paragraph 3.1.8(1). 5.3.6 and the design criteria to implement this change by October 15, 1979.
Sincerely yours, j
John J. Mattimoe
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Assis. tant General Manager
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