ML20002D134
| ML20002D134 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/15/1981 |
| From: | TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML20002D130 | List: |
| References | |
| TAC-43253, NUDOCS 8101190509 | |
| Download: ML20002D134 (12) | |
Text
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O Dockst No. 50-346 License No. NPF-3 Serial No. 678 January 15, 1981 Attachment A APPLICATION FOR AMENDMENT TO FACILITY OPERATING LICENSE NO. NPF-3 FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 Enclosed are forty (40) copies of the requested changes to the Davis-Besse Nuclear Power Station Unit No. 1 Facility Operating License No.
NPF-3, together with the supporting Safety Evaluation and Analysis for the requested change. This requested change deals with the proposal to deautomate the valve shifts caused by Incident Level 5 of the Safety Features Actuation System.
The proposed Technical Specifications changes include pages:
3/4 1-17, 3/4 3-13, 3/4 3-48, 3/4 3-50, 3/4 5-3, 3/4 5-6, 3/4 5-7, 3/4 6-11 and B3/4-12.
By cc:/ W. C. Rowles Director, Nuclear Services For R. P. Crouse Vice President, Nuclear Sworn and subscribed before me this 15th day of January 1981.
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/ Notary Public y..
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Docket No. 50-346 License No. NPF-3 Attachment A Serial No. 678 January 15, 1981 I. Changes to Davis-Besse Nuclear Power Station Unit No. 1 Technical Specifications Appendix A, changes pages:
3/4 1/17 3/4 5-6 3/4 3-13 3/4 5-7 3/4 3-48 3/4 6-11 3/4 3-50 B 3/4 1-2 3/4 5-3 See proposed changes attached A. Time Required to Implement This change will be implemented during the first outage af ter NRC approval for which the plant will be in Operational Mode 4 for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
B. Reason for Change (Facility Change Request 80-278 Rev A) these changes have been proposed during discussion with NRC to address potential problems resulting from inadvertent or premature actuation of SEAS Level 5.
C. Safety Evaluation - attached.
>+ ,* --
ATTACHMENT A Safety Evaluation and Analysis for FCR 20-278 Rev. A Safetv Evaluation At present, the suctions to the decay heat (DH) and containment spray (CS) pumps are automatically transferred from the Borated Water Storage Tank (BWST) to the Containment Emergency Sump on a Safety Features Actuation System (SFAS) trip of incident level 5. This occurs at a BWST level between 49.5 and s5 inches. This change proposes the above described automatic transf ar of these pumps be changed to aanual. Because this modification removes an automated safety feature that would now be manual, the possibility of an accident of a different type not previously in the Safety Analysis Report may be increased. This therefore, identifies a unreviewed safety question. The following analysis is provided to justify this modification.
Analysis The safety function of this transfer is to protect these pumps from cavitation for lack of proper net positive suction heads and to transfer these pump suctions to the containment emergency sump during the recircu-lation mode of operation. The SFAS incident level 5 trip will be used as an interlock to prevent a premature manual transfer. The following table shows the BWST levels required by this analysis for this suction transfer to be successfully performed as a manual transfer.
Table 1 BWST Level BWST Volume Description (Inches) (Callons)
Develop Minimum Level to Transfer Suction to Containment Emergency Sump
- 1. Accident Analysis minimum level to start 36 the transfer per the original analysis
- 2. Instrument string inaccuracy and drift 13.5
,~
- 3. _ovest afc :no tcated r 2 acing to st2. 2 control roo= operator action to transfer Develop Minimum Contained Volume
- 1. SFAS Incident Level 5 Interlock 96 Trip Setpoint
- 2. Interlock Trip Tolerance + 4.5
- 3. Highest (lowest) indicated level that 100.5 (91.5) interlock trip can occur 4 Instrument string inaccuracy and drift + 13.5
- 5. Highest (lowest) actual level that 114 (78) 122,778 interlock trip can occur (this volume m
BWST Level BWST Volume Description (Inches) (Gallons) may not be available for the decay heat or containment spray pump)
- 6. Instrument String drift + 1.2
- 7. Highest (lowest) allowable 101.7 (90.3) interlock trip
- 8. 360,000 gallons required to be added 334.3 360,000 for Emergency Core Cooling System /
(ECCS) analysis
- 9. Lowest safe indicated level for ECCS 448.3 482,778 Analysis in Modes 1, 2, 3, & 4 As shown in the above table, a control room operator will manually perform this transfer when the safety grade level indicators in the control room indicate between 49.5 and 96 inches (4.125 and 8 feet) of BWST level.
This will give a control room operator about 4 minutes to make the transfer safely. Since the plant under the conditions existing at this point will be in an emergency situation for a mininum of 23 minutes, the station procedures will instruct a control room operator to be looking at the BWST level indicators to initiate the manual transfer. As observed from the above calculation table, the minimum level requirements of BWST will be met if the transfer is initiated within 4 minutes after the indicated BWST level drops to 8 feet.
A control room operator will manually perform this transfer about 23 minutes after the initial SEAS trip that started all high pressure injection, low pressure injection and containment spray pumps assuming at their maximum flow. The accident analysis requires 360,000 gallons to be added for ECCS analysis when in modes 1, 2, 3 & 4. As shown in the above table, this condition will still be met and the attached Technical Specifications are changed accordingly.
This chance to manual transfer will provide the same safety function as
, a ceriotaed oy ch_ viesent automatic cransfer as discussed acus _.
Hence, no adverse environment will be created by the change and the safety function of the DH and CS pumps will not be affected. This analysis is considered justifiable to support this proposed modification.
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ATTACHMEEIT B AP 3005.56,2 1
BWST LOLO LVL, XFER TO EMER SUMP
- 1. STMPTOM 1.1 This alarm is generated when any one of the four SFAS BWST level bistables trips.
1.2 Setpoint
8 feet water 1.3 Source Designation: LSL 1525A, LSL 1525B, LSL 1525C, and/or LSL 1525D
- 2. LMIATE OPERATOR ACTION 2.1 Verify that the BWST level is at 8 feet per LI 1525 A, B, C, and D.
2.2 Verify a LOCA condition exists.
2.3 -
Transfer pump suction to the emergency sump by blocking SFAS incident level 2 for DH9A and DH9B and then open.~ng DH9A and DH9B using HISDH9A and HISDH9B. Verify that the.BWST outlet valves DH7A and DH7B start to close as DH9A and DH9B start to open. Verify the transfer is complete by checking the indicating lights on DH7A and B and DH9A and B and by checking that low pressure injection flow has not sub-stantially changed.
- 3. SUPPLEME'iTARY ACTIONS 3.1 Refer to EP 1202.06, Loss of Reactor Coolant, Reactor Coolant Pressure l
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1 SP 1104.04.15 31 DH 831 (DH 830) when DH Pump 1-1 (1-2) line flow is higher. .Then balance the flow to 1500 gpm per line by adjusting the flow control valves DH14A and DH14B. ,
I If no air is available to DH14A and DH14B, the DH injec-tion valve DHlB (DHlA) can be throttled under emergency conditions. This motor operated valve only moves while control switch is held.
9.2.3 Deleted
- 10. RECIRCULATION FROM THE CtNTAINMENT VESSEL EMERGENCY SUMP
/ Following a LOCA, the BWST level will decrease until at the 8 feet level the operator must =anually transfer the suction of the DH and CS Pumps to the emer-gency sump. The operator will open the emergene;' aump outlet valves DH9A and DH93 and close the BWST outlet valves DH7A and B. This operation must be com-
' pleted before the level falls below 5 feet.
No operator signoff is required for Section 10.
10.1 Prerequisites 10.1.1 Low Pressure Injection in progress.
10.1.2 Borated Water Storage Tank water level has reached the low level transfer setpoint (8 feet) as read on LIl525A, B, C, or D ,
/
1J.l.3 The annunciator "BWST LOLO LVL, XFER TO EMER SUMP" may or may not have been received.
10.2 Procedure i
10.2.1 Block SEAS incident level 2 on DH9A and DH9B.
10.2.2 Open DH9A and DH9B using HISDH9A and HISDH9B.
s
/ 10.2.3 Verify that DH7A and DH7B start to close as DH9A and DH9B start to open.
l j 10.2.4 Verify that the transfer is complete by checking the indicating l lights on DH9A and B and DH7A and B and by checking that the Low Pressure Injection flow was not significantly changed.
10.2.5 Continue low pressure injection as needed.
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33 SP 1104.04.15 NOTE: The preceding three steps establish the
" piggyback" mode of operation. If this operation is being formed to provide RCS makeup at high pressure, no further action is required until makeup is no longer needed at which time the pumps may be stopped and DH 63 and DH 64 closed.
If this operation is the result of an RCS
%g leak and the BWST level is approaching 8 feet, continue with the remaining steos.
jr 15 11.2.4 Close the high pressure injection pump minimum recirculation valves to the BWST. This is to minimize the contamination of the BWST and maintain off site radiation levels as low as possible.
15 . NOTE: If, DH 64 (DH 63) and HP 32 (HP 31) are both open, computer alarm Q488 (Q489) will occur.
CAUTION: If the high pressure injectico 15 flowrate drops to f5 35 GPM per pump due to an increase in RCS pressure, stop the high pressure injection pumps 1-1 and 1-2 so as not to damage them.
11.2.5 *SEE ATTACHED SHEET FOR STEP 11.2.5*
11.2.6 When Reactor Coolant Pressure is low enough for 15 l the Decay Heat Pumps to discharge directly to the Da*ctnr Coola-t System at a flow of 2000 gpm, begin Decay deat System recirculation o:
the Containment Vessel Emergency Sump as follows:
15 11.2.6.1 Stop-the High Pressure Injec-tion Pumps-1-1 and 2-if their flow is not needed.
11.2.6.2 Shut the Decay Heat Pump discharge valves to the High Pressure Injection Pump Suction Dh 63 and DH 64.
Section 11 Completed Date
11.2.5 When BWST level reaches 8 feet, transfer pump suction to the emergency sump by blocking SFAS incident level 2 for DH9A and DH9B and then opening DH9A and DH9B using HISDH9A and HISDH98. Verify that the BWST outlet valves DH7A and DH7B start to close as DH9A and DH95 start to open. Verify the t ansfer is complete by checking the indicating lights on DH7A and B and DH9A and B and by checking that low pressure injection flow has not substantially chcnged.
E
l EP 1202.0614 6
a o a u termperature -
n$ h bE If either the i.CS T SAT METERS, the hot *.e;'
E E * ! tj indications, or the incore thermocouple temperatiires g- e uo . indicate super-heated conditions for the existing
' pressure, refer to AB 1203.06, Inadequate Core Cooling U$"35 Guidelines. An increase in the source or intr.r=ediate 8$%uo :
range nucicar instrumentation may also indicate an o co d 3 $ inadequate core cooling situation.
53xEE ' - .-
otM38 2.4.1.3
'If both main and auxiliary feedwater is lost, refer to "30" C-AB 1203.05, Complete Loss of Main and Auxiliary Feed-
$#*j$
O.5."~ water, to aid in restoring auxiliary f eedwater ip the event both OTSGs are dry.
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ma=c. $uad. e.%
$ :% ao 2.4.1.5 Determine the availability of reactor coolant pumps (RCPs). If any RCPs are running, go to 2.4.2.
If all I5. *D
- 3 u5Ied RCPs are off, go to 2.4.3. .
3mu4 & oo
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j gg o 2.4.2 Actions with at least one RCP rnnning Ue5"# -
2.4.2.1 Maintain one RCP running 'per loop (stop other pu=ps). --
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- Continued operation of at least one RCP is desirable.
@"3** The only conditions requiring RCPs be stopped would be 5syg1 J 82m5* if RCS pressure falls below 1650 psig such that 2' AS I E $ ,# incident level 2 is actuated or if the RCP vibration
* " 5 5 as measured by the Bentley-Nevada equipment exceeds 30
- S' l < 3 mills. Note that the X2 (times-two) switch on the 3a S.<= '$5 Bentley-Nevada equipment must be used for the expanded range.
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- If RCS prc$sure cen-
,8}$<
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L4.2.2 Allow RCS pressure to stabilize.
tinues to decrease past secondary side pressure, the "J 3eo3 .
leak is large and section 3 should. be consul.t.ed.
-oe 321"e% 2.4.2.3 Establish and maintain OTSG cooling by adjusting steas pressure via the turbine bypass valves and/or atmos-e ce " $ ": 5 p l " ."* 5 phetic m nt val es.
0 Ccoidown at 100 F per hour to ~g 2 _! " ; ~ w l achieve nn RCS premre of 250 psig. Track tha cool-t
$ $ $ 5 E *'; '
s- down on Figures 2 and 3. Isolate core flood tanks when 50 F subcooling (using RCS TSAT METERS) is
~05 gggeoe 7}* attained and RC pressure is less than 700 psig.
S g5,ga4 .7.lchk SFAS _ level :3.wher)]less than 600 psig.'
5"g5ti _
2.4.2.4 .Co into I.PI cooling described in 2.5.'1 ' '
tU5mj* _
B5uy"g 2.4.3 Actions with no RCPs running -
5c0%$*
$ym))$ 2.4.3.1 Verify that the OTSG 1evel is maintained at 96" on the startup range by auxiliary feedwater.
=,-oo]
U@E%"3 NOTE: If desired, the OTSG Icvel may be raised as high mn-opu as 95% on the operate range to improve RCS coeling
- but the transition must be slow enough to prevent excessive changes in RCS pressure and temperature.
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l EP 1202.06.13 16 .
2.7 Discussion .
- For the purposes of this procedure, a medium sized leak is one for which the HPI pu=p capacity is suf ficient to maintain pressurizer level or RCS pressure. If the HPI pu=ps cannot keep up with the leak, then RC pres-sure vill f all until the LPI system can provide additional =akeup; this is defined as a large leak and is discussed in the next section.
Depending on the size of the leak, the RCS pressure vill slowly or quickly fall to the 1600 psig pressure setpoint of the SFAS for level 1 and 2 actuation. Note that for s=all breaks with a complete loss of feedwater, RCS pressure may not fall low enough- to actuate SFAS levels 1 and 2.
Manual actuation of SFAS could be accomplished by actuating ,
each component in level 1 or 2 or by actuating levels 1, 2, 3, andManual 4 except C.S. pt_.ps, by means of the manual actuation pushbutton.
o j actuation vill result in natural circulation of the RCS and an SFRCS i.,
- actuation. Operator action shall be taken to re-establish the seal ou0* injection and CCW to the MU Pu=ps to allow continuous operation of the SEEO RCPs. Manual actuation should NOT be used unless the SFAS setpoints are ga03 - reached and the actuation does not occur. Once HPI is initiated and 2 $ ": level is restored to enable pressure control, a cooldown can be started.
" $ e* The cooldown should proceed nor= ally with the exception that one of the EU"5 ECCS pu=ps =ust remain in seration in the injection = ode to makeup the M S' 3
- vater lost out of the leak. HPI can be shutdown within the limits of sa35 item 6 of 2.6.1. ,
$ is " E
- 3g If possible the depressuri. ation/cooldown will be complete before the E .h 3WST low level is reached and the "piggybacking" of the HPI and Decay 5055 Heat Pu=ps will not be necessary. If the depreesurization/cooldown cannot
- n. E = $ be cot:pleted in ti=e, the pressurizer level =ay be =aintained by aligning 5E3. the Decay Heat Pumps to take a suction from the emergency su=p and discharge to the suction of the HPI pumps.
"D'l" NU N' u* A flow path from the RCS hot leg to the DE System must be established ga533
@d eo o 8 _within seven days to prevent boren concentration buildup as described in 8 U 3 " E. Section 3.4.8. If this flow path cannot be established, an alternate
- "$$ path through the auxiliary spray line must be used.
.5 0 " E $*
" -,E* If an operator blocks an SFAS signal and changes the status of the actua-3 " 3 il ted equipeene, he is responsible for arsuring proper equipment operation For cuidance on e 2 0 E 'J i and re-ial ir ~.un if recuired until c: t SFAS is reset. .J.,.
3 in E a d t resetting the SFAS after a real or erroneous trip, see Section
$c5co l For additional details on possible consequences of a medium sized leak, E .E .-. * "
e." $ .-U see The Evaluation of Transient Behavior and Small Reactor Coolant S $ 3 'U d System Breaks in the 177 Fuel Assembly Plant - Section-5-(3&W).
"$sEm
'"2 0 $ " -u Notes on Sten 2.4.3.5 -
ca n u a
! 0$$21 When this step is reached, auxiliary feedwater has established a 96" level 26"m? in the OTSGs and no RCS flow exists (forced or natural) . Depending on the Uu$e8 size of the break, the RCS may repressurize enough to reach the code safety
" 3 f' 5 3 - valves setpoint. If the electrematic relief is available, the RCS pressure
.E '** 5 a o j may be reduced manually. If not, the RCS pressure will be relieved by the
"*8
- '*/ break and the safetv>3 if the pressure goes that high. At some pressure,
/ the energy escaping from the break (and the electromatic or safeties if used)
~- -, _ , , . _ -
EP 1203.0614 a
18 a
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1.4 Supplementary Actions
$. Implement Site Emergency Procedure, EI 1300.04 DTE8"'
55o"M CAUTION: DO NOT BLOCK AND OVERRIDE ANY SAFETY EQUIPMENT EXCEPT AS SPECI-Um533 FIED IN SECTION 2.4.3.
82u umnau uo
, og g g 3.4.1 If the flow rate between the two HPI lines for an E!I Pump 53 3g; becomes unbalanc2d, throttle the HPI valves and sp'.it the flow ojguwu between the injection lines. Do NOT throttle the line with the "3"u3 high flow below the flow rate shown on Figure 4.0. Assure
@4> ,g3 proper HPI operation per Section 5.0 of SP 1104.07, "HPI Oy,"u Operating Procedure".
E c. S w* $
"55t" I*$:SE 20= 2 ..
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3 5' at Eis n o o .c x
u,ya, 3.4.2 Verify the LPI pumps are injecting into the RCS when RCS pres-
=
>,ga g sure decreases to approximately 200 psig by reading FI DH2B and 3 ,m, TI DH2A on C5716. No throttling of the LPI valves is required gs :
,,,, m, if both LPI pumps are in operation since roechanical stops are ggyyj installed on the. cooler outlet valves. Assure proper LPI opera-SOe54 tion per Section 9 of SP 1104.04, "LFI Operating Procedure".
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==
4
- 50 3.4.3 If a DH Pump has failed and a break does not exist outside of
- gi<? containment, close the suction on the disabled pu=p, open DH831 iE*E* or DH830, and balance flows using DH14A and DH14B if available u$""
o o=mm or DHlA and DH1B if DH14A and DH14B cannot be throttled.
ow= n=
.Ewo* 3.4.4 Stop any non essential equipment such as reactor coolant pumps, 55$I makeup pumps, etc. Although the RCPs will probably trip on a E"5o5 loss of CCW and seal injection, DO NOT STOP MORE THAN ONE RCP h Sog, PER LOOP UNLESS A MINIMUM OF 3000 gpm TOTAL DECAY HEAT FLOW HAS 0gga,7 BEEN ESTABLISHED.
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- e _" 3 fe 5 k 3.4.5 If LPI flow is greater than 1000 gpm eer ou=o for 20 minutes, the I yj,-3 operator may stop the HPI pumps. Unless the HP1 pumps are pigg:
l _i~~wx o backed, the HPI pumps must be stopped before the suction is manual-l $$$5j} ly transferred to the emergency sump on low BWST level (8 feet).
l g u=gg; If LPI flow is less than 1000 gpm per pump, open HPI to LPI cross-sg g g e q g connect as per Section 11 of the DH and LPI Operating Procedure, agagcg SP 1104.04 before the suction is transferred to the emergency sump.
E*IEsi -
t$5=5*
, 32u$28 3.4.7 See Section 4.0 of this procedure for guidance before overriding T e d 'ij d any other safety equipment.
$ 3$ m "i $
e Yj# 3.4.8 Monitor RB pressure and tertperature and if CS Pumps are in opera-l Te e $ 0 " $ tion, assure CS 1530 and CS 1531 throttle when recirculating l $$35IC f rom the emergency sump.
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t j ..** Dockat No. 50-346 License No. NPF-3 Serial No. 678 ATTACHMENT C January 15, 1981 Description of Operation During normal plant operation the BWST Outlet Valve is open and the corresponding Containment Emergency Sump Valve is closed. An inter-lock exists between the two valves that would prevent the sump valve I from being opened until the BWST Outlet Valve is fully closed.
On a Level 2 SEAS actuation, the valves will remain in their normal i position. At this point, the blocking of Level 2 SFAS signals will still not allow the Containment Emergency Sump Valve from being opened until the BWST Outlet Valve is closed. When Level 5 of SFAS is ac-tuated neither valve will move. At this point, if the Level 2 SFAS signal is blocked, the Level 5 signal will block the interlock allowing the operator to manually open the Containment Emergen y Sump Valve.
When the Containment Emergency Sump Valve begins to open, another inter-lock between the two valves will start closing the BWST Outlet Valve.
The transfer to the sump will be totally manual and no automatic opera-i tion will be involved.
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