ML19295E768
| ML19295E768 | |
| Person / Time | |
|---|---|
| Issue date: | 10/21/1980 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Ahearne J, Gilinsky V, Hendrie J NRC COMMISSION (OCM) |
| Shared Package | |
| ML19295E769 | List: |
| References | |
| FOIA-81-80 NUDOCS 8012080383 | |
| Download: ML19295E768 (6) | |
Text
(
a bnN/""
OCT 211980 MEMORANDUM FOR: Chairman Ahearne Commissioner Gilinsky Comissioner Hendrie Comissioner Bradford THRU:
William J. Dircks, Executive Ofrector for Operations (Signed William J.Dircks FROM:
Harold R. Denton, Director Office of Nuclear Reactor Regulation
SUBJECT:
RULE ON FIRE PROTECTION PROGRAM FOR NUCLEAR POWER PLANTS OPERATING PRIOR TO JANUARY 1,1979 (SECY-80-483A)
Enclosed are revisions to Sections III.G.2., III.G.3. and III.L.7 of the proposed fire protection rule. These revisions supercede all others concerning these Sections previously proposed by the staff.
The staff recoctnends these revisions, whether these three Sections are made applicable only to pre-79 operating plants where the issues involved are still open, or whether these Sections are backfit to all pre-79 operating plants.
The phrpose of the revision to III.G.2 is threefold--minor technical improvements; making the requirements of the Section applicable to non-safety associated circuits; and providing for accepting devi6tions from the gequirements of this Section by exemption, rather than by I believe use of an equivalent
- clause within the Section itself.
the fomer method for accepting deviat:ons is more appropriate here, since it would better assure consistency of treatment in this key area of the fire protection program.
The purpose of the revision to III.G.3 is to add a requirement for providing fire detection and fire protection systems, which was inadvertenfly :Duittted.
^
c.
'd
\\
}/
Contact:
E. G. Case, NRR 492-7726 80 129g9 3
4 The Comnission The purpose of the revision to III.L.7 is to add language that makes it clearer that we are concerned with all types of fire-induced failures of non-safety circuits associated with systems and equipment needed for safe shutdown--not only with non-safety circuit failures that prevent operating of the safe shutdown systems, but also with failures that could result in mal-operation of the safe shutdown systems in such a manner that it is more difficult to cope with plant transients than would result from simple non-operation of the safe shutdown systems.
/y w Harold R. Denton, Director
[ Office of Nuclear Reactor Operation
Enclosures:
V As stated cc: SECY OGC OPE DISTRIBUTION W LS.
Central FiQft EGCase HRDenton RVollmer R!iinogue VStello HShapar WDircks Eou A'/P OFFICE h...N R.
Sh.
. EDO.
.y suanave >lEGCasehb.
. HRDen' ton.
WJDi-r s carc)10/20/80.
.10/3.t/.80..
.10/to /.80
^
cm FA aa a T oni Ti r F FI C E r 1979-289 369
maa*
10/20/80 Reclace LLL G-2 and ill_ G-3 on pages 46 and 47 with the following:
2.
Where cables or equipment, including associated non-safety circuits which could preve'.t operation or cause maloperation due to hot shorts, open ci rcui ts, or shorts to ground, of redundant tr ins of systems necessa ry to achieve and maintain hot shutdown conditions are located within the same fi re area outs ide of conta inment, one of the following means of assuring that one of the redundant trains is f ree of fi re damage shall be provided:
(a)
Separation of cables and equipment, including associated non-safety circuits, of redundant trains by a fire barrier having a three-hour rating.
Structural steel forming a part of, or Supporting, such fire barriers shall be protected to provide fire resistance equivalent to that required of the barrier; or (b)
Separation of cables and equipment, including associated non-safety ci rcuits, of redundant trains by a horizontal distance of more than 20 feet, with no intervening combustibles or fire hazards.
In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area; or (c)
Enclosure of cable and equipment, including associated non-safety circuits,of one redundant train in a fire barrier having a one-hour rating.
In addition, fire detectors and an automatic fire suppression system shall be installed in the fi re a rea.
10/20/80 Inside non-inerted containments, any one of the fire protection means specified above shall be provided. Alternatively, one of the following fire protection means shall be provided:
(d)
Separation of cables and equipment, including associated non-safety circuits, of redundant trains by a horizontal distance of more than 20 feet wi th no intervening combustible or fire hazards; or
~
(e)
Installation of fire detectors and an automatic fire sugpression system in the fire area; or (f)
Separation of cables and equipment, including associated non-safety circuits, of redundant trains by a noncombustible radiant energy shield.
8 Alternative or dedicated shutdown capability, / independent of cables, 3
systems or components in the area, room or zone under consideration, shall be provided:
(a)
Where the protection of systems whose function is required for 8/ Alternative shutdown capability shall be provided by rerouting, relocation or modification of existing systems; or dedicated shutdown capability shall be provided by installing new structures and systems for the function of post-fire shutdown.
10/20/80
. hot shutdown does not satisfy the requirements of paragraph G.2 of this section; or (b)
Where redundant trains of systems required for hot shutdown located in the same fire area may be subject to damage from fire suppression activities, or from the rupture or inadvertent operation of fire suppression systems.
In addition, fire detectors and an automatic fire suppression system shall be installed in the area, room or zone under consideration.
b 10/20/80 Reolace 11I L.7 on oage 61 with the following:
7 The safe shutdown equipment and systems for each fire area shall be isolated from associated non-safety shutdown circuits in the fire area so that hot shorts, open circuits, or shorts to ground in the associated circuits will not prevent operation or cause maloperation of the safe shutdown equipment. The separation and barriers between trays and conduits containing assoc:ated circuits of one safe shutdown division and trays at d conduits containing associated circuits or safe shutdown cabies fron the redundant division shall be such that a postulated fi re involving associated circuits will not prevent safe shu tdown.10/
10/
An acceptable nethod of comolying with this al ternative would be to meet Regulatory Guide 1.75 position 4 related to associated circuits and IEEE 384-1974 (section 4.5) where trays from redundant safety divisions are so protected that postulated fires affect trays from only one safety division.