ML20126G064
| ML20126G064 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 03/23/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20126G063 | List: |
| References | |
| NUDOCS 8103260109 | |
| Download: ML20126G064 (6) | |
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Enclosure 040.76 >
O In accordance with section 9.5.1, Brar.ch Te'chnical positi on ASB 9.5-1, position C.4.a.(1) of h'RC Standard Review plan and section III G .
of new Appendix R to 10 CpA Part 50, it is the staff's position that cablin g for redundant sa fe shutdown systems should be separated by wallsrehaving rating a three-ho or equivaient protection (see section III.G.2 of Appendix R) .
That is, cabling rewired for or associated with the primary cethod of sh td u own, sfould be-physically separated by the equivalent oba.three-hour e rat d fi re barrier from cabling required for or associated with the redundant or alternat shutdown. e method of To assure that redundant shutdown cable systems and all other cable systems that are associated with the shutdo n cable systems are s eparated from i
each other so that both are not subject to da' mage from a sin l g e fire ha:ard, we require the following information for each system needed to bring the plant to a safe shutdown.
040.166
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\9*5*1) prcvide a table that lists all equipment includin g instroentation and vital
- support system equipment required to achieve and maintai shutdown. n hot and/or cold For each equipment listed: ~
a.
Differentiate between equipment required to achieve and maintain hot shutdown and equipment required +4 achieve and maintain cold shutdown, b.
Define each equipment's locztion by fire area ,
c.
Define each equipment's redundant counterpart 4
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040.77 d.
Identify each equipment's esser.tial' cabling' (instrumentation, control, and power). For each cable identified: (1) Cescribe the ca ble routing (by fire area) from source to terminatica, and (2) Identify each fire area location where the cables are separated by less than a wall having a three-hour fire rating from cables for any redundant shutdown system, and
- e. '
List any proble areas identifi'd 'by item l.d.(2) ateve that will e
be corrected in accordance with Section III.G.3 of 4pendix R (i.e., alternate or dedicated shutdown capability).
340.167 (9.5.1) Provide a table that lists Class lE and Non-Class 1E caties that are associated with the essential sa fe shutdown syste:.: ider.ti fied ir, item 1 a bo ve.
For each cable listed: (* See note on page 3).
a.
Define the cable's association to the sa fe shutdown system (c :- cn power source, common raceway, separation less than IEEE Standard-384 guidelines, cables for equipcent whose spurious oparation will adversely affect shutdown systems, etc.),
i b.
Cescribe each associated cable routing (by fire area) frac scur:e to termington, and
, c.
1
- Identify each location where the associated cables are separated l
1 by less than a wall having a three-hour fire rating from cables required for or associated with any redundt.nt shutdown system.
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040.78.
1040.168 (9.5.1) Provide one of the- following for each of the circuits identified in item 2,. : a boye:
(a)
The results of an analysis that der.onstrates that failure caused by open, ground, or hot.skrt of cables will not affect it's associated shstdown sistem,
- Note
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(b)
Identify each circuit requiring a solution in accordance with-section !!!.G.3 of Appendix R,' or "
4 (c) Identify each circuit meeting or that will be modified to meet tne requirements of section Ill.G.2 of Appendix R (i.e. , three-hour wall. -
20 feet of clear space with automatic fire suppression, or one-hour barrier with automatic fire suppression).
040.160 To assure compliance with GDC 19, we require the following information be (9.5.1) provided for the control room.
If credit is to be taken for an alternate or dedicated shutdow method for other fire areas ~(as identified by item 1.e or 3.b above) in accordance with section III.G'.3 ' fonew Appendix R l to 10 CFR Part 50, the following information will also be required f:r each of these plant areas.
a.
A table that lists all equipment includ!ng instrumentation nd vital support system equipment that are required by the pricary method of achieving and maintaining. hot and/or cold shutdown. -
- NOTE I
Option 3a is considered to be one method of meeting the requirerente of Section II.G.3 Appendix R. If option 3a is selected the informat:cn recuested in items 2a and 2c above should be provided in general teret and tne infor.- ;
mation requested by 2b need not be provided. I l
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040.79 P
b.
A table that lists all equip:ent frf;luding instrumentaticr and yttal .
supp;rt system equipment that are required by the alterr. ,
ate dedica ted, or reccte method of achieving and rafntaining t.o and/cr' c:1d shuth '
- c. Identify es:h alternat shutdo c, equi; ent listed in ite t.h at:ye 4
with essential cables (instrumentation, centrol, and ;>:=er) re that a 1
located in the fire area containing ,the pricary shutdo-n equipcent .
Er each etuip . ant listed ;rovide one of tne foll: ing:
(I) Detailed ele:trical schematic cra ir.gs that sh:w the esser.tial t cables that are duplicated else here and.are electrically '
isolated frc: the subject fire' areas, or '
i (2) The results of an analysis that deconstrates that failure '
(open, ground, or hot sh:rt) of each cable identified will not affect the capability to achieve and raintain Fct or cold shutd:wn. .
d.
Provide a table that lists Cass IE and S:n-Cass 1E cables that ar ,
. associated with the alternate, dedicated,or re cte r.ethod Of :hutd:wn.
For each ite listed, identify each as:ociated cable located in the *!n area containing the pric.ary shutd:wn equipment. .
For each cable 50 idatified , t pr0Yide the results of an analysis that de castrates that failure (opes, '
ground, or hot short) of the associated cable will not advet:ely affect the alternate. dedicated.or ra ote r.ethod of shutd:wn.
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040.80 1040.170 (9.5.1) The residual heat removal syst'ed is 5,enerally a low pressure system in interfaces with the high pressure pridary coolant system. To preclude a LOCA through this interface, we require compliance with the retcr. ends-tions of Branch Technical Position P.53 5-1. Thus, this interface nost litely consists of two redundant'.and independent retor operated valves with dive.s interlocks in accordance with Branch TechnicalThese Position IC55 3.
two motor operated valves and their qssociated cable cay be subject to a single fire hazard.
It is our concern that this single fire could cause the two valves to open resulting in a fire-fr.itiated LOCA through the subject high-low pressure system interface.
To assure that this interface and other high-low pressure interfaces are adequately protected from the effects of a single fire, we require the following information:
a.
Identify each high-low pressure interface that uses redundant electrically controlled devices (such as two series motor o;erated valves) to isolate or preclude rupture of any primary coolant boundary.
b.
Identify each device's essential cabling (power and control) and i describe the cable routing (by fire area) from source to termination.
c.
Identify each location where the identified cables are separated
. by.less than a wall having a threc-hour fire rating from cables '
for the redundant device.
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, 040.81 i
d- for the areas identifieg ;
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bases and just;(;c,g; es L0 t .
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