ML051450531

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Rev. 0, Event Review Team Timeline - March 2003 MP-2 Reactor Trip
ML051450531
Person / Time
Site: Millstone Dominion icon.png
Issue date: 03/17/2003
From: House A
Dominion
To: Schneider M
Office of Nuclear Reactor Regulation
References
FOIA/PA-2005-0208
Download: ML051450531 (15)
v • d • e


Text

t Steven Unikewicz-Rev. 0, EventReviewTeam Timeline -March2003MP-2 Reaco Trip Pg From:

<Alex_J_House~dom.com>

botrnfai4.f To:

<sms2@nrc.gov>, <SteveSarver@dom.com>, <Stephen_E_Scace@dom.com>,

<Denny_Hicks @dom:com>, <Clark_D_Maxson @dom.com>, <BillJ_Hoffner@ dom.com>,

<StephenrJ_Baker@ dom.com>, <MichaeL__Baughman @ dom.com>,

<Vincent_M_Wessling@dom.com>, <Patti_A_Luckey dom.com>, <Eric_J_Dean@dom.com>,

<RichardA_Perry dom.com>, <Robert_W_Hoffmann@dom.com>, <James_R_PelchatEdom.com>,

<Richard_W_Mcintosh @dom.com>, <DianeFredericks @ dom.com>

Date:

3/17/03 10:18AM

Subject:

Rev. 0, Event Review Team Timeline - March 2003 MP-2 Reactor Trip Please review the forwarded Unit 2 March 7,2003 Reactor Trip event timeline, RevO, which has been prepared by Robert Borchert with input from various sources. Additionally, the charging specific issues were reviewed by Tom Ripple.

Please be aware that this timeline is intended to be expanded in content based upon additional discoveries, your feedback, and planned verification/validation of specific timeline items.

Alex House Dominion Nuclear Connecticut, Inc.

Millstone Root Cause Program Coordinator (860)447-1791 x0827 Forwarded by Alex J House/MILLSTONE/VANCPOWER on 03/17/2003 10:01 AM Robert A Borchert To:

Alex J House/MILLSTONE/VANCPOWER@VANCPOWER, 03/17/2003 10:00 Stephen E Scace/MILLSTONENANCPOWER6@VANCPOWER, Jeffry AM A Langan/MILLSTONE/VANCPOWER@VANCPOWER, Skip J Jordan/MILLSTONE/VANCPOWER@VANCPOWER, Pierre F L'Heureux/MILLSTONE/VANCPOWER@VANCPOWER, Clark D Maxson/MILLSTONE/\\ANCPOWER @VANCPOWER cc:

Subject:

Rev. 0, Event Review Team Timeline - March 2003 MP-2 Reactor Trip

Alex, Attached please find Rev. 0 of the Event Review Team Timeline for the MP-2 March 7, 2003 Reactor Trip. I have made two changes from the draft version that I sent out on 3/16/03; Corrected a typographical error on page 13 ('Note' became "Not")

Changed time that PEO entered charging pump cubicle from 14:44 to 14:47 based on recent information from security gate logs Please call me if you have any comments on this product Borch (s l (See attached file: Mar_2003Timeline.doc)

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment March 7, 2003 13:21 Reactor operating at 100% power.

Pressurizer pressure - 2250 psia CVCS operating within normally expected values:

Pressurizer level 65%

  • "C" charging pump operating
  • Charging flow rate approximately 45 gpm
  • Letdown flow rate approximately 40 gpm
  • RCP bleedoff flow rate to VCT approximately 4 gpm
  • VCT level steady at approximately 85%

13:21 Released SP 2401D, "RPS Matrix Testing," for performance High Risk Surveillance 14:07:54 I&C began RPS Matrix Testing - Trip Circuit Breakers (TCB) 1 and 5 were opened as part of test 14:39:22 TCB-2 and TCB-6 were opened (as expected) while testing "A-C" matrix.

Reactor Trip TCB-1 and TCB-5 opened due to a switch malfunction.

CR-03-02300 14:39:22 to 14:39:23

  • Main turbine/generator trip Normal trip response

Not unusual to see 1 or 2 safety

  • 2-MS-252 valves weep from a 100% power
  • 2-MS-242 trip - 6 is more than expected
  • 2-MS-246
  • 2-MS-247 Valves are listed in order that
  • 2-MS-245 alarms were received
  • 2-MS-254 14:39:27 Pressurizer level Hi/Lo annunciator alarm received for both Channels "X" Alarm setpoints are:

and "Y"

  • 1%

l above program level

  • 5% below program level Page I of 14 March 17, 2003

, 4 Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 14:39:27 "A" and "B" charging pumps start Pressurizer level was 65.6%

  • "B" charging pump started at 14:39:27.5038 Pressurizer pressure was 2244 psia
  • "A" charging pump started at 14:39:27.6129 14:39:28 Atmospheric steam dump valves opened SG pressures were greater than the normal opening setpoint of 920 psia - No "Quick Open" signal -

CR-03-02395 14:39:28 to 14:39:32 The following main steam safety valves opened:

  • Highest observed SG 1
  • 2-MS-242 pressure was 1008 psia
  • 2-MS-246
  • Highest observed SG 2
  • 2-MS-254 pressure was 1017 psia
  • 2-MS-252
  • Valves are listed in order that
  • 2-MS-247 they opened
  • 2-MS-245
  • CR-03-02310 14:39:34 to 14:46 Charging header pressure (P212) indicated fluctuating pressure between All 3 charging pumps were 2000 and 2500 psig. Charging flow (F212) indicated fluctuations operating between 32 to 48 gpm with a general decreasing trend that settled out at about 38 gpm with a discharge header pressure of about 2667 psig at about 2 minutes following the start of the "A" and "B" charging pumps 14:39:43 to 14:40:38 Several charging pump low lube oil pressure alarms were received and System Engineer says this is cleared for the "A" and "B" charging pumps normal following start of an idle pump 14:39:49 "A" condenser steam dump valve opened Valve appears to have modulated open on its normal opening setpoint of 880 psia - No "Quick Open" signal 14:40 Entered EOP 2525, "Standard Post Trip Actions" 14:40:10 to 14:40:42 The 6 main steam safety valves closed SG pressures were about 920 psia 14:40:29 Auxiliary Feedwater Auto Start signals generated - SG blowdown Setpoint is SG level < 26.8%

isolated - timer started for auto AFW pump start II Page 2 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 14:41:32 Atmospheric steam dump valves closed 14:41:49 "B," "C" and "D" condenser dump valves opened Valves appears to have modulated open on their normal opening setpoint of 5350F - No "Quick Open" signal - CR-03-02305 and CR-03-02426 14:41:50 Radiation monitor RM-8997 (Radwaste Exhaust Particulate) indication Was reading about 380 to 410 cpm begins to increase (reading about 450 cpm and increasing) prior to trip 14:41:51 "B," "C" and "D" condenser dump valves closed 14:41:46 to 14:43:55 The 6 main steam safety valves stopped "weeping" 14:42:27 "B" SGFP steam stop valves closed.

"A" SGFP remained operating 14:43:25 to 14:43:37 Heater drains punmps and 2 condensate pumps stopped Normal post-trip actions 14:43:57 to 14:43:58 "A" and "B" Auxiliary Feedwater pumps automatically started 14:44 Radiation monitor RM-8123A (Unit 2 Stack Particulate) indication begins Was reading about 100 to 110 cpm to increase (reading about 125 cpm and increasing) prior to trip 14:46:25 Pressurizer Level Channel "Y" Lo-Lo level alarm received - all Setpoint is

  • 20%

pressurizer heaters de-energized 14:47 to 14:48

  • Main feedwater block valves closed (2-FW-42A and 2-FW-42B)

Normal post-trip actions. Main

  • SGFP "B" discharge isolation valve closed (2-FW-38B)

FW supplied to SGs via bypass valves from "A" SGFP 14:47 Aux. Building PEO entered charging pump cubicle and noticed that water Security gate log shows PEO was gushing out of the discharge relief valve tell-tale holes at about 15 entering through door 239E at gpm each for the "B" and "C" charging pumps, and at about 2 gpm for the 14:45:48 - reasonable time to "A" charging pump. The PEO also noted that 3 valve hand wheels were reach charging pump area lying on the floor.

CR-03-02333 14:48 Entered TSAS 3.4.4.b, Action b (No pressurizer heaters are operable)

Pressurizer level < 20%

14:48:25 to 14:49:58 Numerous (14) charging low flow alarms are received Setpoint is < 25 gpm 14:49:00 to 14:50:26 Charging header pressure fluctuates between 2225 psig and 3089 psig.

When pressure spikes to 3089 psig, flow decreases to zero. When pressure goes to 2250 psig, flow goes to about 28 gpm.

Page 3 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 14:49 Entered TSAS 3.0.3 - No charging pumps are operable - can not meet No indicated charging flow requirements of LCO 3.1.2.2, 3.1.2.4 and 3.5.2.d 14:50 Unit Supervisor (US) directed Plant Equipment Operator (PEO) to close discharge valves for "B" and "C" charging pumps 14:50:20 "C" charging pump is stopped SOE log shows pump

  • stopped at 14:50:20.832
  • started at 14:50:20.8328
  • stopped at 14:50:21.2311 14:50:28 Charging header pressure stops spiking - charging header pressure is "A" and "B" charging pumps are about 2055 psig operating 14:50:28 to 14:50:34 Charging header flow increases from 0 to 18 gpm 14:50:32 to 14:53:00 VCT level decrease stops and starts increasing Level decreased from 85.1 % to 81.2% from time of trip to time when "C" charging pump stopped 14:50:34 "B" charging pump is stopped Charging flow goes to zero 14:52:35 to 14:52:39 Letdown isolation valves closed (2-CH-515 and 2-CH-516) 15:00
  • Radiation monitor RM-8997 (Radwaste Exhaust Particulate)

The highest value recorded by the indication has increased greater than 8000 cpm and continues to PPC for RM-8123A was 249 cpm increase.

at 14:59:54.

  • Radiation monitor RM-8123A (Unit 2 Stack Particulate) indication has increased to about 225 cpm_

15:00:07 Pressurizer Level Channel "Y" Lo-Lo level alarm cleared - backup Caused by RCS heatup - ADV pressurizer heaters energize opened in response to heatup 15:03 "B" and "C" charging pumps isolated. "C" discharge relief valve is seated. "B" discharge relief valve is leaking at 10 gpm onto the floor 15:03:41 to 15:03:44 Operators closed breakers for pressurizer proportional heaters Pressurizer pressure = 2075 psia 15:06:44 "A" charging pump is stopped Pressurizer pressure = 2148 psia Pressurizer level - 23%

15:07:57 Pressurizer Level Channel "Y" Lo-Lo level alarm received - all Setpoint is < 20%

pressurizer heaters de-energized Page 4 of 14 March 17, 2003

b Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 15:09 Re-verified "B" and "C" charging pump discharge valves are closed. "B" CR-03-02301, CR-03-0231 1, discharge relief valve leaking at 0 gpm. "A" charging pump discharge CR-03-02313, CR-03-02337 relief valve leaking at 2 gpm.

15:16 Shift Manager declared an "Unusual Event - Delta 1" due to RCS leakage 15:16 Entered TSAS 3.4.6.2, Action b (RCS leakage)

Unidentified leak rate > I gpm 15:21

  • Radiation monitor RM-8997 (Radwaste Exhaust Particulate)

The highest value recorded by the indication has increased to approximately 12000 cpm and begins to PPC for RM-8997 was 12589 cpm decrease at 15:21:18.

a Radiation monitor RM-8123A (Unit 2 Stack Particulate) indication has decreased to about 195 cpm and continues to decrease.

15:23 "Unusual Event - Delta 1" message was released IRF 2003012 15:24 PEO verified suction and discharge valves open on "A" charging pump Dual verification with SRO 15:27:21 Started "A" charging pump. No indication of charging flow, no decrease Pressurizer pressure - 2020 psia in VCT level Pressurizer level = 18%

15:45 An update to the "Unusual Event - Delta 1" message was released 15:46 Station Duty Officer notified NRC of "Unusual Event - Delta I" 15:51 Aux. Building PEO noted that the "A" charging pump was hot. He could No indicated charging flow.

feel the heat radiating from the running pump. The suction stabilizer was too hot to hold a hand against. There was steam coming from the tell-tale hole on the discharge relief valve.

15:51:53 Stopped "A" charging pump Pressurizer pressure = 1950 psia Pressurizer level 17.7%

15:52 Entered EOP 2532, "Loss of Coolant" 15:55 Decision made to align charging to "alternate charging flow path" via the No log entries - time is speculated HPSI system.

based on observed changes in SI header pressure that occurred at about 1600.

15:59 Placed Auto Aux. Feedwater Over-ride handswitch in pull-to-lock and AFW not needed. "A" SGFP I secured "A" and "B" AFW pumps maintaining SG levels Page 5 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 16:00:30 to 16:01:00 Charging header pressure decreased from 1960 psig to about 370 psig, Caused by opening cross-tie and SI header pressures increased from about 225 psig to about 360 psig.

valves to HPSI header 16:04 Containment radiation monitor sample fans (F39A and F39B) were These were stopped to align H2 stopped.

monitors for operation 16:05 Closed charging header isolation valve (2-CH-429) 16:07 "A" charging pump discharge isolation valve closed (2-CH-339)

From "rough log" 16:05 to 16:20 Aux. Building PEO vents suction stabilizer for "A" charging pump. The Times are approximate and are pump discharge spool was also drained to the CVCS drains collection based on observed L9796 level tank (which showed a level increase of 9%).

change at 16: 10.

16:20 Entered TSAS 3.5.2, Action a (Facility I HPSI is inoperable due to aligning to the alternate charging path) 16:24 Verified "A" charging pump discharge isolation valve open From "rough" log 16:24:37 Started "A" charging pump. No indication of charging flow through SI Pressurizer pressure - 1862 psia header, no decrease in VCT level, no increase in pressurizer level.

Pressurizer level = 17.2%

Charging header pressure and SI header pressure increased to approximately 1875 psig and 1860 psig, respectively.

16:27:05 Stopped "A" charging pump.

16:28:26 Opened RWST to charging suction isolation valve (2-CH-192) 16:28:45 Closed VCT outlet isolation valve (2-CH-501) 16:31:33 Started "A" charging pump. No indication of charging flow through SI Pressurizer pressure = 1844 psia header, no increase in pressurizer level.

Pressurizer level = 17%

16:32:43 Stopped "A" charging pump. PEO noted that the pum oa

1Biitl, 16:35 Health Physics is taking containment air samples in case a containment entry is required.

16:35 Not meeting RCS Inventory Safety Function for EOP 2532. Decision made to not transition to another EOP since best efforts were being made to recover inventory.

Page 6 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 16:35 Decision made to restart the "C" charging pump with the discharge relief CR-03-02507 valve gagged (to stop the leak). A hose was fitted from the relief valve tell-tale hole to direct the leakoff to the floor drain (since the bellows on the relief valve was ruptured, the water was coming from the pump suction).

16:35 to 16:39 "C" charging pump discharge isolation valve opened 16:37 to 16:43 Pressurizer Pressure Low - SIAS Block Permit alarms received Setpoint is c 1850 psia 16:38 An update to the "Unusual Event - Delta 1" message was released IRF 2003013 16:42:47 "C" charging pump started. Charging header pressure and SI header Pressurizer pressure = 1818 psia pressure increased to approximately 1910 psig and 1840 psig, Pressurizer level = 17.1%

respectively. Indicated flow through loop 2A SI header increased from

-37 gpm to approximately 15 gpm.

16:43 Pressurizer level observed to be increasing 16:54 Exited TSAS 3.4.4, Action b. Pressurizer level > 20% - pressurizer heaters are operable 16:55:43 Pressurizer Level Channel "Y" Lo-Lo level alarm cleared - backup Pressurizer level > 20%

pressurizer heaters energized.

17:29 Radiation monitor RM-8997 (Radwaste Exhaust Particulate) indication has decreased to < 3000 cpm 17:30 Pressurizer pressure = 1992 psia and pressurizer level = 45%

RWST level is observed to be decreasing - expected response 17:37 Stopped RWST recirculating pumps due to RWST level < 95%

18:00 Pressurizer pressure 1992 psia and pressurizer level = 65%

18:02:33 Stopped "C" charging pump Pressurizer level is restored, no letdown available 18:05 Containment sump pumped. Consideration given to RCS leak outside containment. Sump level increase verified to be at a normal rate.

I Page 7 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 18:50:47 Started "B" charging pump - injecting via alternate charging flow path No log entries nor other information available concerning opening of discharge isolation valve 18:53:35 Stopped "B" charging pump. Pressurizer level changed from 67% to 68.5% (as indicated by PPC level indication LI 10Y) 19:36 Stopped "A" and "C" reactor coolant pumps EOP 2541, Appendix 8, step 2 19:45 Commenced plant cooldown per EOP 2532 19:56 Blocked SIAS per EOP 2532 20:00 Entered Mode 3* (Tav, > 300'F, pressurizer pressure < 1750 psia) 20:01 Exited TSAS 3.5.2, Action a for Facility 1 HPSI pump No longer required for Mode 3*

20:04 Started "B" boric acid pump - aligned to charging pump suction.

20:04:15 Started "B" charging pump - borating RCS via alternate charging flow path 20:07 Placed "A" HPSI pump in pull-to-lock EOP 2541, Appendix 8, step 9 20:10:43 Loose Parts Monitor Alarm re-set (received following reactor trip)

CR-03-02316 20:32 Blocked Main Steam Isolation (MSI) actuation signal SG pressure < 700 psia 20:50 An update to the "Unusual Event - Delta 1" message was released for LCO 3.0.3 was entered at 14:49, exceeding the time allowed per LCO 3.0.3 to place the unit in Hot TS require that the unit be in Mode Shutdown (Mode 4) - RCS temperature was - 4901F 4 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> - CR-03-02315 21:20 Installed jumpers to remove SIAS open capability from LPSI injection EOP 2541, Appendix 8, step 5 valves 21:55 Stopped "B" boric acid pump - aligned charging pump suction to RWST RCS temperature = 4330 F 21:57 US notified that the opening and closing coils for shutdown cooling EOP 2541, Appendix 8, step 6 suction and isolation valve (2-SI-651) are installed 22:18 Entered TRM 7.1, Table 7.1.7, Action a - valve 2-SI-651 is being made SM Log should say "Action b" operable in preparation for SDC initiation (Appendix R) 22:29 Containment sump level begins increasing at a higher rate Containment radiation monitor fans (F-39A and F-39B) are still

_"Off' Page 8 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 22:54 Exit conditions for EOP 2532 are met - transitioned from EOP 2532 to OP 2207, Plant Cooldown 23:00 Stopped "D" reactor coolant pump and started "A" reactor coolant pump Auxiliary spray from charging is to allow concurrent RCP and SDC operations not available 23:13:59 "A" SGFP stopped - condenser backpressure 7 inches Hg and Steam pressure was too low to increasing keep steam jet air ejectors running 23:21:57 "A" SGFP discharge isolation valve closed (2-FW-38A)

Feeding steam generators using "A" condensate pump 23:26 Started "A" auxiliary feedwater pump 23:46:31 Received alarm for "Condenser Steam Dump/Bypass Vacuum" block It appears that the operators broke condenser vacuum 23:58:15 Loose Parts Monitor alarm received No explanation for this alarm given

~~~March 8,2003_

00:11:27 SG #1 Main Steam Isolation Valve (MSIV) closed 00:13:27 PPC alarm received for high containment sump leak rate > 1 gpm Containment radiation monitor fans (F-39A and F-39B) are still "Off' - radiation monitors not available 00:30:35 PPC alarm received for high containment sump leak rate = 1.657 gpm 00:37:51 SG #2 MSIV closed 00:50:27 Stopped "B" charging pump - RCS temperature = 2950F Pressurizer pressure - 400 psia Pressurizer level = 65%

01:08 Entered Mode 4 (Hot Shutdown) - Holding pressurizer pressure - 400 psia and RCS temperature = 2950F for I&C LTOP surveillance 01:18 Chemistry reports RCS boron concentration = 1142 ppm at 00:30 Shutdown Margin requirements satisfied 01:39 Placed "C" HPSI pump in pull-to-lock OP 2207, step 4.12.6 01:44:15 PPC alarm cleared for high containment sump leak rate = 0.797 Pm 01:46 Terminated "Unusual Event" Page 9 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 01:53 to 07:10 Numerous "C" reactor coolant pump seal controlled bleedoff high flow alarms received 02:01 Pumped containment sump from 81% to 10%

02:12:59 PPC alarm received for high containment sump leak rate = 1.006 gpm 02:16 to 04:07 Numerous Facility 1 and Facility 2 ICCMS trouble alarms received 02:20 "A" condensate pump stopped - feeding steam generators using "A" AFW pump 02:43 Containment radiation monitor sample fans (F39A and F39B) were started 02:45 to 02:52 PPC alarms received for containment particulate and containment gaseous CR-03-02414 radiation monitors rising 03:53:03 to 04:07:57 Containment radiation monitor sample fan F-39A stopped and started 3 Fan stopped to change filter paper times 04:15:23 to 04:27:21 Containment radiation monitor sample fan F-39B stopped and started 3 Fan stopped to change filter paper times

- HP started a containment remote air sample from RM-8262 at 04:40 04:16:40 Started "A" LPSI pump for initial SDC preparations SDC boron mixing 04:20 NRC phone check - NRC requested confirmation that "Unusual Event" Routine daily phone check had been terminated 04:50 Pumped containment sump from 78% to 10%

05:01:53 Stopped "A" LPSI pump 05:05 Chemistry reports SDC boron concentration = 2077 ppm at 04:32 05:09 Closed all Safety Injection Tank outlet isolation valves OP 2207, step 4.9.4 05:46 Started "A" ESF room ventilation fan 05:50 Established Low Temperature/Over Pressure (LTOP) protection OP 2207, step 4.13 Page 10 of 14 March 17, 2003

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 05:53 to 06:05 Containment radiation monitor readings reached their highest values during this time:

  • RM-8123A (Zl containment particulate) -.

1E+6 cpm

  • RM-8123B (ZI containment gaseous) - 16,000 cpm
  • RM-8262A (Z2 containment particulate) - 582,000 cpm
  • RM-8262B (Z2 containment gaseous) = 16,000 cpm 06:00 Plant conditions at time of shift turnover to dayshift on 3/8/2003:
  • RCS temperature = 2780F
  • Pressurizer pressure - 352 psia Pressurizer level - 50%
  • In procedure OP 2207, "Plant Cooldown"
  • Active TSAS: 3.0.3 (CVCS) and 3.3.3.8 (AVMS) 07:30 Unit 2 stack gas radiation monitor (RM-8132B) increased from = 48 cpm to over 100 cpm due to flushing of the RCS hot leg sample lines 08:24 Pumped containment sump from 85% to 10%

08:46 Chemistry reports RCS boron concentration = 1174 ppm at 08:04 08:46:15 Started "B" charging pump - suction from RWST Pressurizer pressure 351 psia Pressurizer level = 44%

08:52 to 08:53 Stopped "B" and "C" circulating water pumps and cross-tied condenser waterboxes 09:45 Both letdown backpressure control valves (2-CH-201P & Q) are reported un-isolated in preparation for placing letdown in service 09:55:31 Stopped "B" charging pump Pressurizer pressure = 341 psia Pressurizer level = 76%

10:22 Valve 2-SI-709 (Shutdown Cooling isolation) is open in preparation for shutdown cooling 10:41 RCS pressure is less than 280 psia with RCPs in operation - starting 8 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> clock is to prevent RCP hour clock seal degradation - CR-03-02314 11:00:49 Manual disconnect switch for valve 2-SI-652 closed Shutdown cooling preparation Page 11 of 14 March 17, 2003

I Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 11:05 to 11:07 Shutdown cooling isolation valves (2-SI-651 and 2-SI-652) opened 11:07 Pumped containment sump from 79% to 8%

11:22:05 Started "A" LPSI pump Shutdown cooling initiation 11:49 Auxiliary building -45 foot elevation (Aerated waste tank room) is posted as a high radiation area 11:50 Removing decay heat via shutdown cooling Pressurizer pressure = 256 psia Pressurizer level = 73%

12:03 Auxiliary building -45 foot elevation ("A" and "B" ESF rooms) are posted as a high radiation areas due to shutdown cooling operation 12:45 Commenced troubleshooting Reactor Protection System "A-C" matrix 13:15 Started "B" boric acid pump for recirculation of "B" boric acid storage tank 14:31 Pumped containment sump from 78% to 10%

No SM Log entry 14:42 Entering containment for air sampling prior to inspection 14:51 Health Physics bypassed local alarm for charging pump area radiation monitor (RM-7894) 14:55 Held briefing for radiography in charging pump area 15:27 Pressurizer spray AT (main spray) exceed 200F - Engineering notified 15:36 Entered Mode 5 - Exited TSAS 3.0.3, Entered TSAS 3.1.2.3 (no Tave < 200TF operable charging pumps) 15:37 Exited the following TSAS:

No longer applicable in Mode 5 3.1.2.4 (2 charging pumps operable)

  • 3.5.3.a (Operate HPSI and lower mode ECCS)

Exited the following TRM:

  • 7.1.7, Table 7.1.7-1, item b (Appendix R for 2-SI-651)
  • 7.1.17, Table 7.1.17-1, items b and c (Appendix R for 2-MS-65A&B) 15:48 Opened "A" charging pump circuit breaker per OP 2207, "Plant Cooldown" Page 12 of 14 March 17, 2003

t.

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Time Description of Event Comment 16:01 Upon re-entry to containment found a leak from the "C" RCP vapor seal Leak later reported to be approximately 1 to 2 gpm CR-03-02312 16:24:23 Started "B" charging pump raise pressurizer level and to add lithium for Pressurizer pressure - 252 psia RCS pH control Pressurizer level = 46%

16:48:49 Stopped "B" charging pump Pressurizer level = 56%

16:50 Started radiography in the charging pump area Radiation monitor alarms received due to radiography 17:05 Exited TSAS 3.3.3.8 (AVMS)

Not required in Mode 5 17:47 Pumped containment sump from 78% to 10%

20:19 Filled both steam generators to 85% indicated level - stopped "A" AFW pump 20:22 Assessed impact of stopping RCPs on shutdown safety assessment -

OP 2264, step 4.3.5 determined that both S/Gs will remain available for RCS decay heat removal via natural circulation 20:22 Stopped "A" and "B" reactor coolant pumps 20:30 Entered TSAS 3.4.9.1 (RCS cooldown exceeded 30'F/hour limit) -

CR-03-02320 cooldown rate was noted to <31 TF/hour and less than the transient limit of 50_F/hour - cooldown rate was immediately restored to < 30'F/hour 21:07 Pumped containment sump from.78% to 10%

21:39 Notified that radiography is completed in charging pump area 21:52 Plant cooldown is terminated - RCS Tavc = 1780F Page 13 of 14 March 17, 2003

11.

Millstone 2 - March 2003 Reactor Trip Sequence of Events Timeline - Rev. 0 Data Sources:

1. Millstone 2 Shift Manager's Log e-SOMS entries from 03/07/2003 at 00:00 to 03/09/2003 at 05:58
2. Health Physics Log e-SOMS entries from 03/07/2003 at 00:00 to 03/09/2003 at 00:00
3. Sequence of Events Log computer printout (SOLDATA.DAT;3097) - post trip SOE log from 03/06/2003 at 08:29:02 to 03/07/2003 at 14:44:19
4. Sequence of Events Log computer printout (SOLDATA.DAT;3103) - SOE log from 03/07/2003 at 14:30:35 to 03/07/2003 at 15:30:35
5. PPC Alarm Messages computer printout (QUEPRT.LIS;58) from 03/07/2003 at 13:01:07 to 03/07/2003 at'21:01:03
6. PPC Alarm Messages computer printout (QUEPRT.LIS;65) from 03/07/2003 at 21:01:03 to 03/09/2003 at 00:11 :07
7. Operations "rough logs" from 3/7/2003
8. Plant Process Computer analog and digital data - stored at a 2 second resolution
9. Draft timeline of events generated by Event Review Team on 3/11/2003
10. Draft event timeline for charging system generated by Engineering on 3/14/2003
11. Security gate log 03/07/2003 from 14:00:00 to 23:00:59 (Stilphen, Jordan, Ewers and Saulter)

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