ML19220C914
| ML19220C914 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/31/1979 |
| From: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| References | |
| NUDOCS 7905160057 | |
| Download: ML19220C914 (9) | |
Text
7-Con +inhocy Questuins g_gg PAS / nss
~
A.
What should be done if main coolant pumps are lost?
3/3/
)
1.
Can decay heat be removed 1y natural circulation?
a.
Has this type of B&W riant ever been tested to establish 4
natural circulation?
b.
Natural circulation of 3 M.I. plant should be tested?
c.
Is auxiliary feedwater system available? Demonstrate operability.
d.
Is adequate supply of feedwater available?
e.
Can auxiliary feedwater system operate without electric power (AC and/or DC)?
1.
Are there steam-driven a.f. pumps?
2.
Can they be operated under existing steam conditions (32 psi)?
3.
Check all details of auxiliary feed operation, especially control and instrumentation.
f.
Can other RC Pumps be made operable?
2.
RHR decay heat removal system.
a.
Is it operable when depressurized?
b.
Can block valves be opened?
Have steps been taten to minimize clogging?
c.
Check to see that temporary strainers removec.
2.
Shield items needed for possible maintenance.
3.
Consider backup HX and/or pumps.
4 Service H O operable?
2 d.
Will one loop be kept in reserve as a backup?
Have all valve alignments been checked prior to initiation?
e.
3.
Vent through pressurizer relief valves and makeup with HPIS a.
Relief valve vent--with makeup.
1.
HPIS Do we have adequate makeup H 0?
2 Is boron a problem?
(too much--too little)
Are valves and supply of H O t' refill RWST 2
2.
Advisability of holding relief valve ope' for a long time as opposed to cycling.
4.
Safety valve vent with makup (use PDRV when depressurizing) a.
Same HPIS Qs as 3.
b.
Sump recirc.
I D0516 005]
f) \\ \\ 0 00N
B.
What would we do if we lost A/C power?
1.
In part, use auxiliary teed in natural circulation mode.
See A.l. tor natural circulation groblems.
A 2.
Are there any auxiliary diesel-engine generators or gas turbine on-site (near site) that could be used to power auxiliary feed? (or later RHR)?
2 3.
Have diesels been tested--are they operable--is fuel supply adequate? Can they be maintained or is auxiliary shielding required for operator protection?
4.
Do breaker operations rely on DC--is it available where needed? Can they be realigned manually given present radiation levels?
5.
Verify CC to AC inverters operable, aligned.
e e
3.
What should be done if RHR system cannot pass flowl
- What if pumps fail?
- What if isolation valves can't open?
i
- What if filters or HX plug?
- Can we set up bypass system external to containment?
- Can letdown flow be bypassed around filters or are coolers clogged?
- Can additional pumps or an alternate subsystIem (pump-valve, HX, etc.) be jury-rigged at site?
- Is shielding available for RHR pump repair or replacement?
- Is consideration being given to how to do it?
i
- What is most desirable high pressure injection mode to fall back on?
e 4
4 What do if we lose pressurizer vent capability, i.e.,
pressurizer electromatic relief ~ valve fails and 1" vent valve fails?
a.
What are all of the alternate pathways to letdown
- coolant, e.g.-
- sample, drain, instrument lines--particularly on pressurizer
- reverse flow in a hp injection or makeup line
- pump seals cooling / infection system
-
- lower pressure systems b.
Is there remote manual' operation of the valving? Can it be jury-rigged?
c.
Can the effluent (coulant) be pumped or directed (pressure induced flow) to the containment? Can it be jury-rigged?
d.
What are the likely leakage points and is there cleanup available--drains,' filter system?
e.
Can the system be isolated if leaks or malfunctions occur?
f.
Are Loth letdown coolers clogged, i.e., have all alternate flow paths been checked?
5.
What if we lose letdown capability?
1.
What other ways do we have for water purification and boron control?
4
- Can we still use parts of the system later'on by jury-rigging to allow ccolant cleanup? Can we add banks of resins?
- What should we do now to lessen further damage to system for subsequent planned re-use?
- Can seal water injection or shutdewn RC p, umps be rigged for letdown?
2.
How can we provide water to the reactor coolant pump seals if letdown system lost?
- Any other sources for seal cooling?
How long can coolant pumos run without seal cooling?
- What are effects on pumps without seal cooling?.
Is failed part of system assessable for repair?
- Can seal water be injected if system is brought to safety valve set point, i.e., with letdown through safety valve relief.
3.
Are there any other systems which could be jury-rigged to act as a (small capacity) backup to high pressure. injection system in the event system pressuie rises and tne high Pressure ECCS pumps fail?
Ref. SAR Section 9.3.4, Figure 9.3-6 e
6.
What to do--H2 recombiners
- Are H monitors working?
(well ?) how long does it take to analyze sampl$s?
- Are purge outlet and inlet valves functional?
- power supply--dc?
--inst. air?
is it available?
Is the recombiner functional?
- is a spare available (from offsite)?
- FSAR states (p. 5.2-38) RB atm. pressure shall be 2 psig before operation of recombiner.
Is this a physical limitation or procedural?
Is function of fan coolers necessary to provide adequate mixing (FSAR states (p. 6.2-40) RB a tm. nixing is ensured by operation of RSCS)?
- Is the H2 control exhaust fan operational?
- spare available?
- Could the nor 21 RB purge exhaust fans be used if H exhaust fan faiis?
2 control
- are these fans on esf buses ?--if not, can they be aligned to the esf buses?
- Are the RB purge air supply fans working?
- Could they be used to pressurize the R3 atm. for dilution a
purposes?
- 'Are they tied to esf buses?
e p
118 07i
7.
What do if lose fan cooling?
1.
Are cont. sprays operable? Do we want sodium thyosulfate injected?
2.
If the RHR is disabled due to clogging, are the sprays affected?
3.
Do we have an effective system.for makeup to the RWST if recirculation is not possible?
4.
Is the containment purge system operable?
5.
Has any consideration been given to jury-rigging a large water tank or sand filter to the purge line discharge for use to control containment pressure if fan-coolers and sprays were lost? This should be imolemented before operations with downside risk are undertaken 6.
Can flow in the purge line be controlled--other than by a butterfly full open or full closed?
\\\\8C,.a,
f Con +cogeng Ques, dos omee m O.
e O
So-32o
$UlQQ
)
w j,y,>
% k, 4_
2 ( ?
/ ~*p u%)
4 fW j( g TMN
/>
- ,,n t hw-Mus. /
h)
N D/g',[iguM. -
E Las([,kw> loh dpwd &
): VAG YU Cid ff~-
Q y w)%
u k>
h(vtk h(v<.
I>.%
..A (h
[Q w' r
+- Da 6j b
w~. t,,ja e'b L
[kcwq mm)
- $,e i
2&I C dnL%
g.<x Drw/
f L'
Hv Lv Mu k A Or yn Q-)
g AJ uj B H a %p SW b'
949 '
Q)
(,y W q w t
,ltyL CN[O' g(
b,1'r,ik-K G7 t
Y
Lb G
s {gwk l
(/fg 6
- L v4
3 e
- wk_,
./ n s
L3.a u
q 1 a <t w%
[Adar
~
r) hA. ~
~t2.J
)u4
,mb-
/
118 0;'3
6-320 6
~ T)' y W'y 2
Mn'A P cv-;.1J4 ea/ pas 4e" Mhmw cwa cn v J y,'
Lw c&L TWh
,- e b
ctwy. p & rpA >
, Q rv
~
Q-N u-A L -q. s % r <..
t' j u
De h-p' L Ao w Aj dm. '
jb kg e'g.
tUM gg
%% 36te4 P g (c.s
/g wb ut&.gp_ w>w
)g fl u % 56. L~ s pq a
JJ i m v ca( o,.l,+o Ct %
L.'p @~L.O4 h clede~Ut Fl; l
l A/C p <s A _ A r,ce r N Si
$ A/c y~7 lb i
M_
va dJ=+
dork m
~
Mo a1 6L es uv a 4 k g e
c
" % WY$
M u-3 9 e-ft/L
&losof
.I%
p$
'^
n
\\\\S n74