ML19344B374
| ML19344B374 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/08/1977 |
| From: | Abel J COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML19344B371 | List: |
| References | |
| NUDOCS 8010080728 | |
| Download: ML19344B374 (7) | |
Text
-
.-a-
. f...... '
- ATTACHMENT G3
(
l
- STATE OF~ ILLINOIS-
-)
)
SS.
lCOUNTY OF COOK
-)
art 1Dar1r g
4 I, ' JAMES S. ~ ABEL, being first duly sworn on oath, depose and l
state that'the following is true:to the best of my knowledge and
. belief:
1.
I-hold a degree in: Engineering from Rose-Hulman Institute
- l of Technology, and.am currently employed as a Section Engineer in the Station Nuclear Engineering Department of Commonwealth Edison 3
Company with responsibility for supervising engineering efforts in connection'with each of Commonwealth Edison's boiling water reactors, 1
. including Dresden Unit 1.
These responsibilities require familiarity
~
with.the upgrading of the Dresden Unit 1 sphere safety devices, modifications of the reactor psotection system and the fire protection j.
for electrical cable as well as other design' aspects of the Unit.
2 p
2.
The upgrading of' sphere safety devices, modifications of the reactor. protection system (RPS) to comply with the reingle failure 4
intent ~of.IEEE 279-1968 and fire. protection for electrical cable in
'the'areaLof containment sphere penetrations and in the cable tunnel Lare being designed and installed as required by the NRC Order for
~
Modification 1.of License,' Docket,50-010, dated June 23, 1976.- This
~
Jorder require'dLthat the modifications be completed following the chemical cleaningLforJdecontamination or..not later than December 31. 1977.
8010'O.8017J8/
n _.,
F m.
g.'
.3.-
The-systems presently-being desig'ned to accomplish the
. intent of the Order are described below.:
~
Upgrading of Sphere Safety Devices L
The' devices within the containment sphere have'been analyzed
{
to determine which devices are necessary for the safe shutdown of i.
'Dresden Unit'l.- These devices'were tabulated and sul:xnitted with 'a 4
i recommended action in Commonwealth Edison Company's June 30, 1975
{
letter to J. G. Keppler, Region III, U.S. Nuclear Regulatory j-Commission.
The following summarizes the actions to be taken for safety f
related' devices located inside the containment.
l a.
Replace'all instrumentation cable that was installed i
before 1970.
r b.
Replace all single conductor power and control cable installed before 1970.
c.-
Replace Limitorque motor operators for AC and DC service j
installed before;1970.
4-
-d.. Provide new power supply / source for six
- 6) motor operated 1
valves that-is not susceptible to failure due to the sphere
' environment.
This...ew : source could include relocation of motor
. controllers outside ofLthe.' sphere due to.the environment
- l
_ qualifications and the-installation of-new sphere penetrations
~
- for power.and.' control cable.
1 '
y
--c m
n
~
(3)
~ Replace existing unqualified instruments with qualified e.
replacement instruments.
l f.
Provide a neutron monitoring system qualified for post-accident conditions.
It will be a. single division system consisting of seven. (7) analogue-sensing, converting, indicating, recording, alarming and tripping channels.
This system will be operational after the design basis event in order to provide the station operator with sufficient and reliable monitoring i
of the status-of the reactor.
This information will be used to mitigate the consequences of an accident.
Modifications of the Reactor Protection System The reactor protection system (RPS) including sensing devices, logic, and scram solenoids will be modified to comply with IEEE 279-1968.
These modificatione a il accomplish the following:
a.
Provide additional circuitry to assure proper system protective action following a single failure within t:0 reactor protection' system.-
- b. ' Provide physical protection to assure channel integrity during malfunctions, accidents, or other unusual events.
c.
Provide additional redundancy and physical: separation to H
assure' channel independence.
' The scopef of the proposed modifications to affect compliance will include the following:-
x.
b g) a.
Isolate existing or new sensing instruments by barrier.
or relocation, as necessary, to provide separation of redundant instruments.
b.
Install two new conduit wireways between sensors and control room to separate RPS digital sensor input cabling from other cables.
c.
Install terminal block cabinets and rearrange conductors at the sphere electrica.1 penetrations to provide two safety system penetrations.
construct barriers to provide additional separation between RPS input and output cable at these penetrations.l d.
Reconstruct existing RPS logic cabinet to provide a four-channel, one-out-of-two twice logic system with two manual i
i push-button scram channels.
Install barriers to provide adequate
~
physical separation between channels.
-e.
Install two new conduit wireways between control room and scram solenoids to separate the RPS scram output signal cabling from other cables.
f.
Install an additional scram backup solenoid to provide redundancy necessary for a two-channel manual scram.
g.
Install'a fixed automatic fire protection system at the
. sphere electrical penetrations and in the cable 'cunnel connecting I
the-.s'phere to the control room complex.
.~
~
.;.y.,
(5) h.
The. outputs of the neutron monitoring. devices will be i
modified, where necessary, to-be compatible with the proposed four-channel RPS ecram logic.
i Automatic' Fire Protection An. automatic fire protection syrtem will be installed'in the i
cable tunnel-and on both sides of the associated containment penetra-
.tions.
The intent of the system is'to detect a fire, alarm the situation and. actuate a water spray.
~ The fire. detection system will use a primary and backup detection system.
The primary system will be a heat sensitive cable on cable-l~
i trays.
The secondary system will use temperature detectors, ionization detectors or other detection systems, appropriate for the location being monitored.
The water spray system will be a zcned dry pipe system that is operated by deluge. valves.
The fire protection system zwater. supply will be obtained from the existing fire protection system.
i i
The fire protection water outside of:the sphere will be supplied directly from the existing system.
The fire protection water inside the sphere will be piped'from the existing fire protection system i
through' isolation valves, and through a spare penetration into the-
.contr.Legent sphere.
The deluge valves for the inside sphere fire
- protection: system wl.ll be ' located in the cable tunnel area outside the' containment-sphere.
The existing fire protection water supplies care continuously pressurized sources of water with alarms on pressure
- failure..
-.,,-....j
g
_ =:-
- 4. - Commonwealth Edison Company.is proceeding as expeditiously i
as possible'to implement the modifications discussed ~in Item 3. of
~
this Affidavit.
As the detailed' design has progressed,-specific design and procurement problems have delayed the final completion r
~
date.
Recognizing the importance of the commitment and the extremely j
- short schedule for such a complex problem,-Commonwealth Edis.on
. established.in Fall, 1976,_a specific engineering project group'for Dresden Unit 1 and is utilizing a critical path method to schedule ~
these activities.
In spite of these best efforts, it is apparent
~
that. procurement, delivery :and construction ~ schedules will prevent completion of the modifications by December 31, 1977.
i 5.
.The chemical cleaning for decontamination of the primary system of Dresden-Unit 1 is now scheduled for November, 1978.
To minimize' personnel' exposure, it is prudent to complete certain portions of these modifications after the chemical cleaning when 1
rad'iation levels are reduced.
6..
To further assureLhealth and safety-of the public, commonwealth.
Edison Company-is taking the following measures:
_ a.- Remove'the plastic: face from.each of the drum level switches.
-This will.qualifyithese switches to perform their ECCS function
~
in-a LOCA environment.
'b.
-R$ view: the. sphere high pressure and drum level sensors, 1
~
~
= switches,:!and' cables ;which initiate the ECCS to1 determine thatL
- -they will' function ~in a LOCA environment.and make modifications
-;asinecessary.
s
.l m.-
l (7) 7.- Commonwealth Edison Company requests that the required completion date for these modifications be extended from December 31,
- 1977,;to December 31, 1978.
/
JAMES S. ABEL f/
V SubscrpAd and sworn to before me i
A day of'. CafAp-
, 1977.
this 0
WnfLL ha1LL8ki.)L>
(/
Notary W ic i
l e
,g
,,..p.
r.
..y, 3
.