ML20149K715

Northeast Utilities Root Cause Investigation 960222 of Millstone Unit 2 Cooldown Events

ML20149K715
Person / Time
Site:	Millstone
Issue date:	06/02/1996
From:	Becker J, Howes S, James Shea NORTHEAST UTILITIES
To:
Shared Package
ML20149K712	List: B16568, Forwards Response to RAI Re RCS Cooldown Weaknesses in NRC Insp Repts 50-245/95-44,50-336/95-44 & 50-423/95-44 on 951227-960207.Corrective Actions:Operating Practices During Cooldown Activities to Operated RCPs Changed ML20149K715
References
NUDOCS 9707300100
Download: ML20149K715 (89)

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I NORTHEAST UTILITIES ROOT CAUSE INVESTIGATION FEBRUARY 22,1996 MILLSTONE UNIT 2 COOLDOWN EVENTS j

Lead Evaluator: J N[

I John Becker ' Da'te 1

Team Members: #d C/4- 7 4

[ ~ S ott owes Date Jim Shea 2 r-g-96 Date d;L J, lid. eAv/90 Vicki Swisher Date i Reviewed By: b z[S Technical Suppo John Rj/M Date i

9707300100 970723 PDR ADOCK 05000245 G PM ,

5/13/96 1 Millstone Unit 2,2/22/96 Cooldown Event Review

EXECUTIVE

SUMMARY

Due to the HPSI valve operability issue on 2/20/96, Unit 2 entered Technical Specification LCO 3.0.3 requiring the plant to be in Mode 5 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br />. During the next 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />, Operations and Engineering personnel attempted to address concerns about potential RCS i temperature transients during shutdown cooling (SDC) initiation. On 2/22/96, the midshift initiated shutdown cooling system operation and was in the process of cooling the plant down from Mode 4 to Mode 5. At 0655, prior to turnover activities, RBCCW flow was valved in to a second SDC heat exchanger in an effort to increase heat removal capability to maintain the cooldown rate established earlier. During the temperature transient that followed, the maximum allowed cooldown rate of 20 *F/hr was exceeded (20 *F is an administrative limit established when the RCS reaches 220 'F; Technical Specification 3.4.9.1, Pressure / Temperature Limits for the RCS, specifies 30 *F until 200 'F is reached).

Mode 5 was reached at 0942,2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 27 minutes after the TSAS 3.0.3 time limit expired. This report addresses both of these events.

The following nine root causes were identified by the Event Review Team (ERT) investigation

In 1994, resolution of whether to use shutdown cooling outlet or inlet temperature (T351Y or T351X) for RCS cooldown rate during shutdown cooling operation was incorrect.

In the weeks prior to the 2/22/96 event, management accepted the risk of not having an i adequate RCS cooldown methodology and procedures.

Management coordination of the cooldown process improvements were less than i adequate.  !

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Development of methods, procedures, and training needed to successfully cool down to Mode 5 using T351Y were less than adequate.

l PORC review of changes to the cooldown process was less than adequate.

Shift decision making process for adding the second SDC heat exchanger was less than adequate.

Operator skills required to maintain an acceptable cooldown rate using T351Y, SDC to RCS temperature, during the addition of the second SDC heat exchanger was less than adequate.

5/13/96 2 Millstone Unit 2,2/22/96 Cooldown Event Review

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Controls specified in OP 2310, Operation of Shutdown Cooling System," and controls selected by the shift were less than adequate for adding a second SDC heat exchanger and maintaining an acceptable cooldown rate.

Use of visual trends provided on the PPC was less than adequate for adding the second ,

SDC heat exchanger and maintaining an acceptable cooldown rate.

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5/13/96 3 Millstone Unit 2,2/22/96 Cooldown Event Review

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1.0 INTRODUCTION

1.1 Event Description f

In the weeks prior to the forced shutdown of 2/20/96, Event Review Team (ERT)  !

activities associated with the heatup events of 1995 identified concerns about '

3 excessive RCS cooldown rates during and following the initiation of shutdown cooling (SDC). The exceedance of RCS cooldown rate limits following the initiation of SDC was captured in ACR #8365, written on 2/20/96 and reviewed with the Shift Manager at 2000. The exceedance ofRCS cooldown rate limits I during the initiation of SDC was not included in the ACR since this temperature i

change was expected to be within design considerations.

) Earlier that day Unit 2 had entered LCO 3.0.3 due to declaring both emergency core cooling systems trains inoperable as a result of high pressure safety injection (HPSI) l

! valve concerns. Based on this LCO, Unit 2 was required to be cooled down to

! Mode 5 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> of1815,2/20/96 (An evaluation ofLCO 3.0.3 and 3.5.3 '

, action requirements will be performed separate from this ERT to determine whether the correct action statement was followed to Mode 5. The results of this evaluation j j will be reviewed with Operations personnel prior to entry into Mode 3.). With the j

, impending need to cooldown, actions were initiated to implement changes to l 7

operating philosophy and procedures associated with the initiation of SDC and to l address the concerns raised by ACR #8365. First, the method of monitoring d

cooldown rate was changed by revising SP 2602B, Transient Temperature, Pressure

. Verification, to use T351Y, SDC to RCS temperature, in lieu of T351X, RCS to

SDC temperature. Second, a Technical Requirements Manual clarification specifying i how to monitor RCS cooldown rate during SDC initiation was written. Third, a change to OP 2310, Shutdown Cooling System, was made requiring equalization of SDC injection temperatures prior to increasing flow from minimum to normal flow rates. Fourth, a briefing was developed to introduce the three changes listed above and discuss using a slower SDC initiation process. These efforts were completed at 2150 on 2/21/96 and immediately followed by PORC approval to continue the RCS cooldown using SDC.

On 2/22/96, the midshift initiated SDC system operation and was in the process of completing the plant cooldown from Mode 4 to Mode 5. The crew realized at

approximately 0430 that the plant would not reach Mode 5 within the 37 hour4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> time limit. Management was notified of this pending Technical Specifications violation.

At 0655, prior to turnover activities, RBCCW flow was valved in to a second SDC heat exchanger in an effort to increase heat removal capability to maintain the cooldown rate established earlier. During the temperature transient that followed,

the maximum allowed cooldown rate of 20 *F/hr was exceeded (20 *F is an i administrative limit established when the RCS reaches 220 F; Technical

Specification 3.4.9.1, Pressureffemperature Limits for the RCS, specifies 30 *F until 200 F is reached). Within 15 minutes of the transient, the Control Operator l

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performing the cooldown rate surveillance procedure, SP 2602B, notified the shin j that the 20 'F/hr cooldown rate had been violated. The shiR immediately reduced  ;

i. SDC flow and stabilized the temperature indicated on T351Y, SDC to RCS Temperature. Mode 5 was reached at 0942,2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 27 minutes after the TSAS 3.0.3 time limit expired.

N 1.2 Scope 1

j As a result of the cooldown events that occurred at Unit 2 during the 2/22/96 shutdown, an ERT was established to investigate the following ACRs:

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i l I e ACR 9243, After Entering TSAS 3.0.3, Unit Did Not Meet Time Rwquirement

, For Cooldown To Mode 5 (Cold Shutdown) l j e ACR 9739, RCS Cooldown Rate Exceeded 30 'F/ Hour Limit After Valving in a ,

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! Second Shutdown Cooling Heat Exchanger In accordance with NGP 2.40," Issues Management and Action Tracking," the ERT performed a root cause analysis for the two 2/22/96 cooldown events using the

guidance specified in NGP 3.15, " Root Cause Evaluation Program." The following j methods were used during the analysis:

i i Event and Causal Factor Chaning was the primary tool used during this

investigation. This method was used to identify the sequence of events and

, causal factors contributing to the events.  ;

! l I Barrier Analysis was used to help identify the barriers that were in place to i prevent the events from occurring.

Chance Analysis was used to assess what differences existed in the plant, procedures, and personnel between this cooldown and previous cooldowns.  !

Management Oversieht and Risk Tree was used to assist in directing the flow of the review and ensuring the review covered all of the significant facets related to procedures, personnel, and hardware.

Data for the event review was primarily obtained from the following sources:

1) personnel interviews,2) shift log,3) plant process computer archived data,

4) completed OPS Form 2602B-1, Transient Temperature, Pressure Verification Data Sheet, and 5) correspondence. The data was used to develop the Event and Causal Factor chart contained in Attachment #8.3. Once th causal factors were identified, the ERT analysed each causal factor to de".sre e similarities and 5/13/96 5 Millstone Unit 2,2/22/96 Cocidown Event Review

t differences. This information was used to identify nine root causes of the cooldown events. Since each of the nine root causes was a result of more than one causal l factor, no one corrective action would resolve a particular root cause. As a result, the ERT developed corrective actions corresponding to each causal factor. The

! combination of these corrective actions become the resolution to the root causes. In accordance with NGP 2.40, Issues Management and Action Tracking, the ERT will develop an action plan containing the corrective actions, description of desired effect, success criteria, responsibilities, resource requirements, and due dates for each causal factor.

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5/13/96 6 Millstone Unit 2,2/22/96 Cooldown Event Review

2.0 REFERENCES

i 2.1 Procedures e OP 2207, Plant Cooldown, Revision 21, Change 6 e SP 2602B, Transient Temperature, Pressure Verification, Revision 10, Change 1 e OPS Form 2602B-1, Transient Temperature, Pressure Verification Data Sheet, Revision 12 i

e OP 2310, Shutdown Cooling System, Revision 19, Change 13  :

2.2 Technical Soecifications ,

i e 3.0.3, Applicability >

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• 3.4.1.3.a, Coolan: Loops and Coolant Circulation - Shutdown e 3.4.9.1/4.4.9.1, Pressure / Temperature Limits - Reactor Coolant System l i l i l e 3.4.9.2/4.4.9.2, Pressure / Temperature Limits - Pressurizer  !

• 3.5.2, ECCS Subsystems - T.v, >300 *F j L l e 3.5.3, ECCS Subsystems - T. , <300 *F l

. Bases for Specification 3.0.3, Applicability  !

l e Bases for 3/4.4.1, Coolant Loops and Coolant Circulation

• Bases for 3/4.4.9, Pressure /Temperatura Limits  ;

i j e Administrative Controls 6.5.1, Plant Operations Review Committee (PORC) l' I

! 2.3 Resign Bases Documentation i

e DBD,3.3.2, Shutdown Cooling System

. FSAR 9.3, Shutdown Cooling System

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e DBD, 3.2.13.2, Temperature i

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i 2.4 Other Documentation e ACR 9243, After Entering TSAS 3.0.3, Unit Did Not Meet Time Requirement For Cooldown To Mode 5 (Cold Shutdown) e ACR 9739, RCS Cooldown Rate Exceeded 30 *F/ Hour Limit After Valving in a ,

Second Shutdown Cooling Heat Exchanger

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• ACR 9748, Operator Unaware of New Cooldown Rate Guidance  ;

• ACR 8365, RCS Cooldown Rate Exceeded Technical Specification Limits l During Plant Cooldowns in 4/94,7/94, and 12/95  !

• ACR 9749, Pressurizer Heatup Rate May Exceed Technical Specification Limit  !

When Restoring Loop Flow Per TSAS 3.4.).3 Action B i e ACR 9645, Under Some Conditions, RCS Cooldown is Monitored With Temperature Points That Do Not See Flow i

• LER 50-336/96-001, Reactor Coolant System Heatup Rate Exceeded Technical  !

Specification Limit ,

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e LER 50-336/96-007, Reactor Coolant System Cooldown Rate Exceeded Technical Specification Limit  !

• LER 50-336/96-011, Plant Shutdown Required by Technical Specifications Completed and Required Time to Enter Mode 5 Was Exceeded ,

e Memo ES-SD-96-026, dated February 20,1996, Millstone Unit No. 2 -  ;

Structural Evaluation of RCS Cooldown Rate in Excess of That Allowed by the  ;

Technical Specifications l e NUSCo Calculation Number 96-SDS-1468M1, Revision 0, dated February 20, 1996, MP2 - Evaluation of RCS Cooldown Transient l

• Memo MP2-O-1036, dated September 30,1994, Transient Temperature I Verification While on Shutdown Cooling  !

e Memo MP-2-O-1037, dated September 30,1994, Request for Engineering ]

Support, Review ofInstrumentation Utilized to Monitor RCS Transient j Temperatures  !

• Memo From Mike Hills to Rick Bonner/ Charlie Nelson, dated October 11,1994, Instrumentation Review for RCS Transient Monitoring l l

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• PORC Meeting Minutes from PORC # 2-96-038 e Completed OPS Form 2602B-1, Transient Temperature, Pressure Verification Data Sheet, Revision 12, from 2/22/96 e Control Room Log from 1750 on 2/20/96 to 1716 on 2/22/96 d e Archived computer data from 4/24/94,7/28/94,12/15/95, and 2/96 e Process Computer Functional Specification, SP204 - Plant Heatup/Cooldown Monitor, Revision 0,3/20/84 e Process Computer Functional Specification, SP204 - Plant Heatup/Cooldown Monitor, Revision 1,9/22/88 e Process Computer Functional Specification, SP204 - Plant Heatup/Cooldown Limit Changes, AWO No. M2 94 03048,5/5/94 i e OA 3, Plant Operations Review Committee, Revision 1 J

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3.0 EERSONS INVOLVED p 3.1 Evaluation Team  !

j John Becker Technical Suppon I

] Scott Howes Operations Jim Shea Technical Support Vicki Swisher Technical Support l c

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3.2 Persons Contacted During the Investigation -

i Nelson Azevedo Structural & Design Support, Supervisor )

John Becker Technical Support, Electrical Systems Supervisor ,

[ John Bemis Technical Support, System Engineer I

i. Joe Bergin Operations, Assistant Operations Manager l l Rick Bonner Operations, Engineering Supervisor l Paul Collette Technical Support, System Engineer l

Mike Cote Operations, Depanment Procedure Coordinator Ted Dubay '

' Operations, ShiR Manager  !

j Brendan Duffy Maintenance, Manager i Tim Hall Operations, Control Operator l' Bill Hunter. Operations, Consultant

! Jim Jorinscay Operations, Control Operator  ;

< ~ Mike Muldoon Operations, Control Operator j Tom Myers Operations, Senior Control Operator

Larry Nelson - Operations, Shin Manager i

Gary Neron Technical Support, System Engineer  !

Ed Seacor Operations, Control Operator l

l - John Resetar Tech Support, Mech Systems Supervisor, ODSEO 2/22/96 j

$ John Riley Technical Support, Manager j Pat Sikorski Operations, Plant Equipment Operator i Rich Spurr Training, Simulator Consultant 3

Martin Van Haltern Safety Analysis, Supervisor ,

j. Rik Wells Design Engineering, Mechanical Supervisor l

Mike Wilson Operations, Manager l Carl Zorn Operations, Control Operator i

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3.3 Additional Suoport Keith Bragg Training, Instructor i Robert DeRosa Stmetural & Design Support, Engineer

- Bruce Ferguson Operations, Control Operator Joshua Spalter Safety Analysis, Engineer '

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5/13/96 11 Millstone Unit 2,2/22/96 Cooldown Event Review

4.0 COMPILATION OF FACTS 4.1 Sequence of Events The following is a listing of the more significant events leading up to and including exceeding of Technical Specification 3.0.3, Limiting Condition for Operation and Surveillance Requirernents," and Technical Specification 3.4.9.1, " Reactor Coolant System, Pressure / Temperature Limits," in the Millstone Unit 2, 2/22/96, cooldown event. The complete chronology of the cooldown event along with contributing factors and causal factors are provided in Attachment # 8.1.

Dateffime EVENTS COMMENTS '

9/30/94 Operations asks Tech Support whether This question arose following a T351X or T351Y should be used to mordtor training session on the RCS.

changes in temperature at the reactor vessel beltline.

10/11/94 Technical Support notified Operations to continue to use T351X.

Late 1/96 Heatup Event Review Team notified various to 2/14/96 management personnel oflikelihood of cooldown issues similar to heatup.

2/16/96 Structural & Design Support analyzed SDC initiation transient from previous cooldown.

2/20/96 ACR #8365 written to indicate cooldown 2000 rates exceeded during previous cooldowns due to use of T351X (did not include SDC initiation transient since this temperature change was expected to be acceptable). ,

l Started revision of SP 2602B.

i Just prior to writing ACR #8365, I TSAS 3.0.3 was entered due to HPSI valves declared inoperable.

~2030 Discussion about Tech Spec clarification to deal with SDC initiation temperature transient.

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Dateffime EVENTS COMMENTS 1

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a 2050 Completed engineering evaluation and  ;

j- found previous transients acceptable for 1 App.G. l 1

2/21/96 Re-write work continues on SP 2602B.

2 0500 f

j 0900-1000 Site notified App. G calculation can not

cover SDC initiation temperature transient.  ;

I i i 1000 Analysis of SDC initiation temperature

transient started.

l' 1230 Management decision not to pursue waiver Thought HPSI valves would be l to remain in Mode 4. declared operable prior to needing to go to Mode 5.

{ Decision not to revise OP 2310, only j provide instructions in brief. j I

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1400 Table-top review of SP 2602B.

I 1500 Validation of OPS Form 2602B-1. Performed by individualinvolved l SP 2602B ready for PORC. in table-top.

1900-2000 Analysis of SDC initiation temperature spike Analysis using delta T and decay -

could not be completed using delta P. New heat only good for current plant j analysis using delta T and decay heat. condition.

l 2000 Plant cooldown stalled at 260 *F. SDC normally initiated at this j point in time in the cooldown process.

e 2100 Analysis supports Tech Spec clarification to CI'arification only good for permit SDC initiation. current plant condition.

4 2130-2150 PORC'd SP 2602B revision, OP 2310 step Decided to start cooldown on j

change, and Tech Spec clarification. 3rd shift.

2/22/96 Secured RCPs and entered TSAS 3.4.1.3.b.

0151  :

} l 0208 Initiated SDC.

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Cooldon Event Review 4

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Date/ rime EVENTS COMMENTS 0240 SDC flow >1000 gpm. Exited TSAS l 3.4.1.3.b. i

~0450 OPS Manager notified TSAS 3.0.3 may be OPS Manager directs not to violated. violate cooldown rate.

0655 Aligned RBCCW cooling flow to second T351X at 2127 and cooldown SDC Hx. rate at -l8 T/Hr 0700 Exceeded cooldown rate of 30 T/Hr Achieved a cooldown rate of specified in TS AS 3.4.9.1.b. -33 T/Hr.

0715 Exited TSAS 3.4.9.1.b.; Cooldown rate of+5 T/Hr.

Violated TSAS 3.0.3 time limit. T351X ~214 7, T351Y ~190 7 0942 Exited TSAS 3.0.3. T351X < 200 7 4.2 Response to Cooldown Issue The ERT categorized cooldown information obtained during interviews, documentation reviews, and data analysis, into three major areas: personnel, procedures, and hardware.

Each of these areas is discussed below.

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4.2.1 Management Awareness and Involvement in Resolving the Cooldown Issue  ;

l The use of T351X, RCS to SDC temperature, versus T351Y, SDC to RCS l temperature, as the appropriate instrument for monitoring downcomer temperature during SDC system operation was first questioned in 1994. The preliminary response was to continue to use T351X as the indicator of overall RCS temperatures. Further investigation was not formally pursued at that time. ,

In late January 1996, the Heatup ERT determined that T351X was the wrong i instrument to use for vessel downcomer temperature. At that time the ERT speculated that cooldown rates may have been violated during previous RCS cooldowns and notified management. Also the system engineer for SDC was concerned over the major temperature transients impacting the SDC heat exchangers during SDC initiation. These issues resulted in data being sent to Nuclear Engineering, Berlin for Appendix G analysis. At that time, no one expected the temperature transient indicated by T351Y during SDC system initiation to be an operating concern.

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1 When Millstone Unit 2 entered the LCO for TSAS 3.0.3, Operations was notified that ACR #8365, "RCS Cooldown Rate Exceeded Technical Specification Limits  ;

During Plant Cooldowns in 4/94,7/94, and 12/95," was being written.

Management was faced with the following issues: ,

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- Trying to determine if the HPSI valves were operable during the cooldown prior to reaching the need to initiate SDC

- The inability to cool the plant down from Mode 4 to Mode 5 without potentially violating Technical Specifications

- If the HPSI valve operability issue was resolved after reaching Mode 5, the l plant could not be promptly heated back up from Mode 5 since the heatup ERT l resolutions had not been fully incorporated

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As a result of the above three issues, management initiated the following separate efforts to provide the ability to cooldown to Mode 5:

- Establishing an Appendix G calculation that could provide a basis for writing a Technical Specification clarification indicating that the SDC initiation temperature transient was not applicable to the cooldown rate surveillance.

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- Revision of SP 2602B, Transient Temperature / Pressure Verification, to include heatup resolutions specified by the ERT which were also expected to accommodate cooldown. The heatup resolutions included performing the Technical Specification surveillance using T351Y during SDC operation, increasing the surveillance frequency to 15 minutes, using both T101 and T109 temperature sensors for pressurizer temperature chang *es, and using Tl15 and T125 separately to determine RCS temperature changes rather than averaging the two sensors.

- Initiating a mixing calculation to prove the temperature of the water entering the vessel downcomer during SDC initiation did not change by 95 *F as indicated by T351Y.

- Developing a Technical Specification clarification specifying the SDC system initiation is of no consequence to the RCS cooldown rate.

- Reviewing OP 2310, Shutdown Cooling System, to determine whether changes were needed for SDC system initiation.

These efforts were divided among Operations, Technical Support, Structural &

Design Support, Thermal Hydraulic Analysis, and Licensing. No particular Department or individual was assigned to coordinate all of the efforts listed 5/13/96 15 Millstone Unit 2,2/22/96 Cooldown Event Review

above. Tasks associated with all of these efforts were completed by 2100 on 2/21/96. PORC was convened at 2130 to discuss approval of SP 2602B and the Technical Requirements Manual clarification indicating that the temperature l transient indicated on T351Y during SDC system initiation was not I representative of the temperature seen by the downcomer. Some technicalissues i required discussion at PORC and caused further delay in approving the procedures and continuing the cooldown to Mode 5. At 2150 PORC approved the documentation and Operations management made the decision to not start cooldown to Mode 5 until the next shift took the watch at 2330. Operations management felt that the cooldown could be accomplished by the 0715 limit (time limit established by TS AS 3.0.3). This judgment was primarily based on the time required to accomplish previous cooldowns, assuming a cooldown rate l between 20 'F and 30 7, and the amount of temperature decrease currently required to reach Mode 5 was 59 *F. Neither of these assumptions represented the 2/22/96 cooldown. The use of T351Y versus T351X caused the operator to be extremely cautious when manipulating SI-657 and as a result maintained a ,

cooldown rate typically well below 15 7. This caused a very slow cooldown compared to previous plant cooldowns. Also since T351X was selected as representing T.y, the temperature decrease needed to achieve Mode 5 was actually 94 F as indicated on T351Y (T125 was at 259 'F at the beginning of the cooldown and T351X was at 199 *F and T351Y at 165 7 at the end of the cooldown).

4.2.2 Operations Response During the Cooldown The midshift on 2/22/96 was informed at the beginning of the shift that they would be cooling down the RCS with the following changes and conditions imposed on the task:

- SP 2602B, Transient Temperature, Pressure Verification, had just been revised

and no training was planned; The crew was notified that the procedure had been validated by a licensed operator and no problems were found in performing the surveillance every 15 minutes.

- SDC system initiation would be performed in a slower manner. The instructions for the slower initiation would be provided in a brief rather than a procedure change.

- The plant had to be cooled down to Mode 5 by 0715 to meet TSAS 3.0.3.

- Visual trends specifically designed to assist in monitoring the cooldown rate were available on the PPC.

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- Even though SDC would be initiated slower to minimize the temperature

change in the downcomer, flow must be greater than 1000 gpm within one hour

after securing RCPs even ifcooldown rate must be violated to achieve this

!' flow.  ;

, 4 l Operations successfully completed the SDC initiation in accordance with the new

{ instructions and initiated RBCCW cooling flow to both SDC heat exchangers. I j They found it difficult to establish and maintain a reasonable cooldown rate using L a combination of T351Y, SDC to RCS temperature, and SI-657, SDC System Hx  ;

Flow Control. With two heat exchangers in operation, the operator was unable l

to open SI-657, SDC System Ex Flow Control in small increments, as minor l t increases in demand caused enough flow to create a larger than desired

!' temperature decrease. As a result, the initial RCS cooldown was very slow and i erratic for approximately two be;s after initiating SDC. The shift discussed 4

raising RBCCW temperature versus isolating RBCCW flow to one heat exchanger. The decision was made to isolate RBCCW flow to "B" SDC heat

_ exchanger. This permitted the operator to open SI-657, SDC System Hx Flow

! Control, to a better operating range on the valve and have much finer control on i flowrate. Approximately an hour later the "A" and "C" RBCCW temperature control valves were raised 4 'F to permit opening SI-657, SDC System Hx Flow 4

Control, further to attempt to achieve better control of the cooldown rate.

I i At approximately 0430 the Shift Manager estimated that the RCS would not j achieve Mode 5 by 0715. The Shift Manager called the ODSEO and

[ subsequently the Operations Manager was called regarding the potential 1 upcoming Technical Specification violation of 3.0.3. The Operations Manager

[ - acknowledged the fact that Technical Specification 3.0.3 time limit would be i exceeded and emphasized the importance of not violating the cooldown rate limit.

At approximately 0630 the shift perceived that the cooldown had stalled.

j. Although the cooldown rate at that time was slowly decreasing, it was still -18

• F/ hour, one of the highest rates all evening. The shift considered the plant j " unstable" and felt they would be more successful, due to their experience for the

!- past few hours, in re-establishing the cooldown with a second heat exchanger in service. There was some discussion about locally throttling RBCCW flow to the second heat exchanger to minimize the impact on the cooldown. However the crew decided that using SI-657, SDC System Hx Flow Control, would be satisfactory fo'r throttling SDC flow. Also using this method would take less time to re-establish the previous, more aggressive cooldown. One of the goals of the shift, at that time, was to minimize exceeding the time limit established by Technical Specification 3.0.3.

The operator intended to cut SDC flow in half through the heat exchangers and then initiate RBCCW flow to heat exchanger "B." Prior to performing these actions, a day shift operator that had arrived early for his shift, was recruited to 5/13/96 17 Millstone Unit 2,2/22/%

Cooldon Event Review

monitor the T351Y, SDC to RCS temperature, trend located on the Shift Manager's CRT. The operator at the CRT was requested to notify the control operator of the direction T351Y, SDC to RCS temperature, wa3 going but not the magnitude of the temperature change. By the time the SDC flow was reduced by approximately one third, the temperature indicated by T351Y, SDC to RCS temperature, had increased approximately 4 T. As a result of the temperature increase, the operator decided to immediately initiate RBCCW flow to the "B" heat exchanger rather than decrease SDC flow further. This was accomplished by opening RB-13.lB, RBCCW outlet valve SDC Hx, which is a full open or full closed valve. Since T351Y, SDC to RCS temperature, continued to increase a few degrees, SDC flow was increased. The introduction of RBCCW and the increased SDC flow caused T351Y, SDC to RCS temperature, to decrease 15 7 in approximately two minutes. SDC flow was immediately reduced using SI-657, SDC system Hx flow control. T351Y, SDC to RCS temperature, immediately started to increase in temperature. When the temperature had risen 4 T, SDC flow was once again increased to try and establish a stable cooldown rate. Within approximately two minutes, T351Y, SDC to RCS temperature, decreased an additional 15 T. One more attempt was made to stabilize the cooldown rate by adjusting SDC flow. By this time,15 minutes had passed and the results of SP 2602B, Transient Temperature, Pressure Verification, indicated the 30 7 cooldown rate limit had been exceeded.

The operator immediately closed SI-657, SDC system Hx flow control, and permitted the T351Y, SDC to RCS temperature, to increase to an equilibrium value. The RCS and SDC system were maintained at this steady state temperature until the day shift resumed the cooldown.

4.2.3 Equipment Response During the Cooldown OP 2310, Shutdown Cooling System, specified using SI-657, SDC system Hx flow control, to throttle SDC flow as a method of regulating the cooldown rate.

Using this valve to throttle flow, with SI-657 nearly closed or more than 50%

open, proved very difficult to establish or maintain a steady cooldown rate. The non-linearity of the flow at these conditions caused the operator to be very conservative in increasing SDC flow.

A visual trend built on the plant process computer prior to the cooldown provided T351Y, SDC to RCS temperature, data. The trend was designed to display exactly one hour's wonh of data on the screen at a time. The values on the temperature scale were designed to correspond to the maximum allowed cooldown rate. Therefore, as long as the temperature remained between the top and bottom of the temperature scale during any given hour, the cooldown rate was acceptable. This visual trend was updated every two seconds. The visual trend was originally built at the Shift Manager's CRT. Although the trend could be moved to other CRTs in the control room, it remained only at the Shift 5/13/96 18 Millstone Unit 2,2/22/96 Cooldown Event Review

a p Manager's CRT throughout the cooldown events. The operator throughout most of the cooldown was adjusting SDC flow and then walking back to the CRT to watch temperature change. Due to the delay time associated with movement of SI-657, SDC system Hx flow control, walking back to the CRT posed no ,

operating problems. When the second heat exchanger was added to the >

cooldown, an additional operator was stationed at the Shift Manager's CRT to provide temperature data to the control operator. This support was needed since the visual trend was left on the Shift Manager's CRT and the temperature response was expected to be much faster with a second heat exchanger and high SDC flow. The display provided accurate and timely data, but since the control operator could not see the trend, the magnitude of the temperature changes during the process of adding the second heat exchanger was not apparent.

4.2.4 Procedure Compatibility in Response to the Cooldown OP 2310, Shutdown Cooling System, provided no instructions regarding the I '

addition ofcooling flow to a second heat exchanger. This resulted in the operators having to determine how to perform the task while monitoring  !

cooldown rate on T351Y, SDC to RCS temperature. The operators had no prior experience in adding a heat exchanger while monitoring T351Y, SDC to RCS i temperature, in either the simulator or in the plant. ,

l 2

l 5/13/96 19 Millstonc Unit 2,2/22/96 Coc!down Event Review

, e a

i

3.0 CONCLUSION

S 2

Due to the complexity of the cooldown events, which involved violating both Technical

, Specifications 3.0.3, Limiting Conditions for Operation, and 3.4.9.1,

Pressure /femperature Limits,9 root causes were identified. Each of these root causes has a number of causal factors associated with it. The following table presents the root causes followed by their associated causal factors.

i

Attachments 8.1 through 8.7 were used to identify the root causes and causal factors.

The drawings contained in Attachments 8.1 and 8.2 were used to illustrate the locations i oft 351X and T351Y, and the typical flow path of the RCS during SDC operation. The Event and Causal Factors chart in Attachment 8.3 clearly identifies the causal factors associated with the events of February 22,1996. Attachments 8.4 and 8.5 illustrate the failed barriers and changes that contributed to the occurrence of the cooldown events.

Attachments 8.6 graphically depicts the RCS cooldown rates from various sensors prior to, during, and following the cooldown event. Attachment 8.7 contains a table of temperatures and cooldown lates obtained from the plant process computer historical files.

5.1 Root Causes and Causal Factors Root Causes & Associated Causal Factors Number on E & C F Chart Esudadhss!&a@aeanadissidhuALAbisb& s ^ M T!sia e Resolution in 1994 of whether to use T351Y or T351X for cooldown rate during shutdown cooling operation was incorrect.

- No feedback was provided by Nuclear Engineering, Berlin #1 to the " thermal striping" issue raised by Operations.

- The Technical Support investigation focused on an RTD #2 that provided the best overall RCS temperature instead of reactor vessel downcomer temperature during shutdown p J**'I.ng operat,jon., ,

,r -r_ ,, - g t' ~ ,

a e Management accepted the risk of not having an adequate RCS cooldown methodology and procedures after being notified of the problem.

- Management did not increase the priority of a #A3 and #C5 cooldown investigation when notified of potential problems between 1/96 and 2/20/96.

5/13/96 20 Millstone Unit 2,2/22/96 Cooldown Event Review

Root Causes & Associated Causal Factors Number on i E & C F Chart I

- Heatup Event Review Team was directed to complete #B4, #D6, and the heatup investigation prior to addressing cooldown #F7 ,

issues thus delaying their timely resolution. l

- Decision not to pursue waiver to stay in Mode 4 since #L8 there appeared to be a good probability of HPSI o erability.

EN$$p$$$$S$7[dS$$$E[d$h![E$$I d $$IDE[EU3!EE$I$EE5[d

. Management Coordination ofcooldown process improvements was less than adequate.

- Informal discussions led to a misunderstanding that #E and #K SDC initiation temperature spike was a non-issue and only required a Technical Specification Clarification.

- Nuclear Engineering - Berlin was not notified of the 37 #G hour time constraint to reach Mode 5.

- Time allotted for researching SDC initiation mixing #H and #I analysis less than adequate.

- Tasks required for cooldown were not fully understood #I, #P, #Q, and #R or prioritized. ,

1

- Not apparent to Operations who to call for support , #M9 with cooldown issues.

- Time allotted for SDC initiation and cooldown to Mode #S 5 was decreased to a less than adequate amount in an effort to develop a Technical Requirements Manual Clarification.

- Operations did not require Engineering to lead #NIO cooldown effort.

5/13/96 21 Millstone Unit 2,2/22/96 Cooldown Event Review

.. .- - . . - - . ~. - -~ - - - - . - . --. . .-

Root Causes & Associated Causal Factors Number on E & C F Chart l Mk 6 m a n dandi$s! = c a;m e d h a u = Ana m m m as?E m mas h udi l e Development of resources needed to successfully cooldown to Mode 5 using T351Y was less than ,

adequate.

l - Decision made to minimize changes to OP 2310 for #11 l l plant cooldown on 2/22 since formal training on procedure changes could not be performed prior to cooldown and meet T.S.A.S. 3.0.3.

- All efforts associated with OP 2310 were based on # 012, #16, #19.1, shutdown cooling initiation rather than plant cooldown 19.2, #20, #V23 using T351Y with shutdown cooling in operation. and #37

- The amount of time to familiarize operators on the new #U SDC initiation process was too lengthy because all of the information was passed on in the briefing rather than including steps in OP 2310. 1

- Operator familiar with SP 2602B upgrade issues was #13,#29,#30,and j used as the only validator on the procedure #31 modifications resulting in the following: a)some unclear steps, b) diflicult to use data sheets, and c) process did not permit timely feedback to PPO on cooldown rate during transient conditions.

- No formal training was given to operators on new #18.1 and #18.2 revision of SP 2602B and only a verbal briefing on SDC initiation modifications.

- No formal training was given to operators on cooldown #21, #22, #Y26, process using T351Y.

- Evaluating the consequences of changing SP 2602B to #Z a 15 minute frequency was less than adequate since the increased frequency caused the operator to invoke additional conservatism with respect to cooldown rate.

- Instructions defining To, indicators were less than #AA adequate since information was not specified in j procedures, training, or briefing. This caused I

conservative judgments to be made with respect to cooldown rate limits and the time Mode 5 was entered.

l 5/13/96 22 Millstone Unit 2,2/22/96 Cooldown Event Review

1 l

. , l Root Causes & Associated Causal Factors Number on E & C F Chart

- PPO had not performed a cooldown in the plant. #36 I

- Licensed operators are considered qualified for any #37 j control room tasks, although training and procedures  !

may not support the least ex ty,parnwn rew nwmne perienced operator.

Etw L Jens m sm321a acJ m .ahis u u and h Jane M A m e n e m m m n dan wnmmewwwwmmemy,au 22Nw e PORC review of changes to cooldown process was less than adequate.

l

- PORC was disorganized. #14 i

1

- There was an urgency expressed during PORC to #15 l approve the procedure so cooldown could commence.

- RCS and SDC System engineers did not attend PORC. #T17 ewenmm wwww OM d.ihides :'S2dLl%SS Jjan ,s ev

~~w~ - ,mm ~~~

- v- :~~ m~m dn5?' s , 2 x s ,. ,,,u, .,

• 5.,e,- & J e Shin decision making process for adding second heat exchanger less than adequate.

- Shin perceived cooldown had stalled, although #30 and #31 cooldown rate was between 12 *F and 18 *F per hour.

- Shia decided their recent experience gave them a better #32 chance for success in adding second heat exchanger than a new inexperienced crew. Knowing what had happened to the cooldown rate with the addition of the second heat exchanger, the subsequent crews chose to take local control of RBCCW flow and throttle the RBCCW flow as heat exchangers were added or removed.

- Shin considered plant " unstable" with cooldown stalled #33 and the next shin unable to take action until aner shiR briefing. The plant was actually stable.

- ShiR objective was to minimize the amount of time #34 Technical Specification 3.0.3 was exceeded which placed a selfimposed time pressure on reaching Mode 5.

5/13/96 23 Millstone Unit 2,2/22/96 Cooldown Event Review

Root Causes & Associated Causal Factors Number on E & C F Chart b h e a d ;ts tE M % $ 1 u s m a d h u w a b w h a d a s h u m m m w & m u $ h d

. Operator skills required to maintain an acceptable cooldown rate during the addition of the second heat ,

exchanger less than adequate. l

- PPO asked the operator he requested to monit,or the #38 cooldown a ate trend to indicate the direction of temperature change, not the amount of the change.

- PPO did not move pre-established visual trends of #39 T351Y temperature parameter to CRT on PPO's desk.

- PPO used digital shutdown cooling flow values to #40 establish a specific flowrate and then fine tuned the adjustment in response to the temperature change indicated by T351Y, SDC to RCS temperature.

- PPO attempted to re-establish an earlier cooldown rate #41 rather than stabilize temperature following the addition ofthe 7- - - s,e,co,nd_ heat e.xchange, s - - ~ - r. ,n,_, - _ .,n.- _ _ e, s .,

h~

• m 1* v~>~c~a.

. ,' %y, %. w dwJh e> '

• v.w -- s m*s+es +ss,* uw ~ ~~44 A w s%+%  %,

e Controls specified in OP 2310, " Operations of Shutdown Cooling System," and selected by shift were less than adequate for adding second heat exchanger and maintaining acceptable cooldown rate.

- SI-657, SDC system Hx flow control, is very non-linear #W24 over it's operating range making it very difficult to perform precise or fime adjustments. The operating band, which provides the best results, is approximately 5% to 30% demand.

- A delay time exists between adjusting SI-657, SDC #X25 System Hx flow control, and seeing the results of the change on T351Y, SDC to RCS temperature. This results in a more conservative cooldown rate and a longer time to achieve that rate since changes are made in small increments.

5/13/96 24 Millstone Unit 2,2/22/96 Cooldown Event Review

Root Causes & Associated Causal Factors Number on E & C F Chart finssaamssskstaedesnudsina!!!hwdaead5ssaamasaameddlidbili e Visual trends provided on the PPC were less than adequate for adding second heat exchanger and ,

maintaining acceptable cooldown.

- Visual trends needed by the PPO to monitor cooldown #39 rate were located on Shift Manager's CRT which is many feet from the SDC controls.

- PPO had digital displays for shutdown cooling flow #40 information located on display "SDC" at the C04 CRT rather than temperature trend data.

1 I

i 5/13/96 25 Millstone Unit 2,2/22/96 Cooldown Event Review

6.0 CORRECTIVE ACTIONS Each of the causal factors listed in Section 5 was evaluated and corrective actions were assigned to eliminate or minimize recurrence of the causal factor. These corrective actions, along with the root causes and causal factors listed in Section 5, are presented in the table that follows. The resolutions are intended to both correct the deficiencies associated with the cooldown events of 2/22/96 and reduce the likelihood of a similar event occurring in the future. The combination of these recommended resolutions provides a resolution for each root cause.

Some of the corrective actions are easily implemented and are considered very effective in resolving the causal factor. Other corrective actions, in order to be effective, require a longer time in development and implementation. These corrective actions typically involve some type of design change or Technical Specification clarification. The department responsible for implementing the corrective action is also listed.

In accordance with NGP 2.40," Issues Management and Action Tracking," an action plan will be developed from the corrective actions listed in this Section. The action plan will contain the following information:

- Description of causal factors )

- Corrective actions

- Interim corrective action if final action (s) cannot be implemented in a timely manner-

- A description of the desired effect of the corrective action (s)

- The success criteria for the corrective action (s)

- Implementation responsibility j

- Resource requirement  ;

- Due date(s) 1 l

4 5/13/96 26 Millstone Unit 2,2/22/%

Cooldown Event Review t

- t L

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor l

• l E & C F Chart i@dadMadEhsdiSsgarssauddss$$$2M&MSAbn$$hrid$$$dd@SS@$dds$$$$03$3ddIdEEEh^$8sESEffdiiE@ld5E$$ l t

• Resolution in 1994 ofwhether to use T351Y or T351X for i

cooldown rate during shutdown cooling operation was incorrect. .

Use AITTS to ensure the following: 1) responses for I

- No feedback was provided by Nuclear Engineering, Berlin #1 to the " thermal striping" issue raised by Operations. information are received in an expeditious manner, 2) a t contact person familiar with the issue is assigned to follow- ,

up on the request, and 3) the request is documented and tracked. [AII Departments] j Notify originator requesting information of the results of  :

their inquiries to ensure that the results meet the expectation  :

of the originator. [All Departments] -

Provide a better communication link between Nuclear i Engineering and Unit personnel by having nuclear Engineering present at the site. [ Nuclear Engineering] i

. - The Technical Support investigation focused on an RTD #2 During resolution of an issue, documentation should be l that provided the best overall RCS temperature instead of maintained and distributed to all parties involved in the  !

reactor vessel downcomer temperature during shutdown resolution process to ensure the correct information is [

cooling operation. researched and a satisfactory response is provided. Ensure  !

the system engineeris involved.

[ Design Engineering & Technical Support]  !

I l

5/13/96 27 Millstone Unit 2,2/22/96 Cooldown Ewnt Review  !

P 1

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart ddtJMLAss ~5:G' NJMinli/ANEbdiD$$ Dfh b k3iM!M Mf;3N M 4&$h hh$id M dkilhd wm m 4

AsiW:sssMSWs2J:dd:i( s2%4n!$1552E$lhddeddhiSfi@$db5Ss5iisnLSsb2ds::s :::sil:N$$nniMd.

• Management accepted the risk of not having an adequate RCS cooldown methodology and procedures after being notified of the problem.

- Management did not increase the priority of a cooldown #A3 and #C5 - hfanagement philosophy should be changed from " goal" investigation when notified of potential problems between oriented to " operationally ready" oriented in prioritiing 1/96 and 2/20/96. werk. This philosophy would place the highest priority on problems that could impact placing the plant in a safe condition with regard to current operating status. s

[All Departments]

- Develop a risk assessment training program to enable management to better prioritize work. [ Training]

- Utilize the new Determine Course of Action (DCA)  ;

process as soon as it is available to assist in prioritizing work efforts associated with plant readiness.

[AII Departments]

- Heatup Event Review Team was directed to complete the #B4, #D6, and Allocate resources in accordance with the " operationally heatup investigation prior to addressing cooldown issues #F7 ready" method ofprioritization developed.

thus delaying their timely resolution. [All Departments]

i

- Decision not to pursue waiver to stay in Mode 4 since #L8 Resolution to this causal factor is included under the root i there appeared to be a good probability of HPSI cause " Management Coordination ofcooldown process operability. improvements less than adequate" and resolution for establishing instruction for what a project lead must consider 5/13/96 28 Millstone Unit 2,2/22/96 Cooldown Event Review h

. . . - _ _ _ . _ _ _ _ . _ _ _ _ _ _ _ _ ______._._________.______.__._____________--.m._______.._ _ _ _ _ _ _ _ _ _ _ . _ _ . _ _ _ . _ _ _ _ . _ _ _ _ _ _ _ _ . _ _ - _ - _ . _ _ _ _ _ _ _ _

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart Nd h man w siassm uha m laemana a am newaam z a .a m u d id a s a a m m m m a d e m o w d S $ h t i$ 5 E ,

. Management Coordination of cooldown process improvements less than adequate.

- Informal discussions led to a misunderstanding that #E and #K The following resolutions are being suggested for the 6 i SDC initiation temperature spike was a non-issue and causal factors listed: [ Technical Support]

only required a Technical Specification Clarification.

-Designate a project lead for the entire effort. This lead should typically be an engineering supervisor. The basis

- Nuclear Engineering - Berlin was not notified of the 37 #G for this recommendation is that these particular supervisors hour time constraint to reach Mode 5. are 1) trained in coordinating people and projects,

2) typically interact with personnel in other Departments and

- Time allotted for researching SDC initiation mixing #H and #J are thereby effective in obtaining cross discipline support, analysis less than adequate. and 3) respcasible for maintaining and monitoring plant systems.

- Tasks required for cooldown were not fully understood #I, #P, #Q, and #R - Provide instructions in the form of a procedure, or prioritized. Department instruction, or briefing specifying that the lead on a project should perform the following: i

- Not apparent to Operations who to call for support #M9 t I

with cooldown issues. . Obtain agreement from all management personnel associated with project on goal (s) ofproject.

- Time allotted for SDC initiation and cooldown to Mode #S i

5 was decreased to a less than adequate amount in an . Notify support personnel of project goal (s) and if effort to develop a Technical Requirements Manual applicable, the priority of these goals.

Clarification.

. Notify all management personnel associated with project ifit is determined during the project that the goal (s) needs modification.

5/13/96 29 Millstone Unit 2,2/22/96 Cooldown Event P.eview

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

. Determine all possible success paths and if the situation is high priority, such as the 2/22/96 cooldown issue, establish resources to evaluate all possible success paths.

. Estimate resources required to perform project.

. Estimate time to complete work and notify management throughout project if this varies.

. If the deadline to complete work is going to be exceeded, re-evaluate the viability of the success path.

. Notify support personnel of constraints involved in project such as amount of time available to complete each task.

- . Ensure analyses are completed and accurate before notifying management .of the viability of a success path.

- Operations did not require Engineering to lead #NIO - Each project should have only one lead. Ifone clear lead is cooldown effort. not available, Operations should notify the Director thet a project lead has not been identified. [Operatiotis]

5/13/96 30 Millstone Unit 2,2/22/96 Cooldown Ewnt Review

- _... _.m.. -_ _ _ .

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart l

$$acminhaudainwsamsnummmededim5fidsli$$$hsofEAG=iahmuns53Sd!AlddniEhd

~

. Development of Resources Needed to successfully r

cooldown to Mode 5 using T351Y less than adequate.

- Decision made to minimize changes to OP 2310 for #11 - Always follow DC 1, DC 2, and DC 3 in determining level plant cooldown on 2/22 since formal training on of detail, verification requirements, type ofvalidation, procedure changes could not be performed prior to training requirements, and basis information when modifying cooldown and meet T.S.A.S. 3.0.3. procedures. [ Operations]

- Perform a simulator validation with licensed operators to  :

confirm proper level of detail required in a procedure to support monitoring cooldown rate with T351Y versus T351X. Ifin the future the simulator is not available for a particular procedure va'idation or there is not enough time available for a simulator validation, ensure licensed operators are selected as independent reviewers and for a table-top validation. Also ensure that the Operations Department Procedure Coordinator leads the procedure effort in accordance with DC 2 and DC 3. [ Operations]

- Upgrade OP 2310 to provide the following instmctions for the least experienced, qualified operator and ensure the SDC System Engineer concurs with these changes:[ Operations & ,

Technical Support]

. Use oft 351Y to monitor cooldown rate

. Initiation methods for SDC flow followed by throttled RBCCW flow 5/13/96 31 Millstone Unit 2,2/22/96 Cooldown Ewnt Review e

?

- . _ . - . _ _ . . _ . - _ . - =_ --_--____------_._-.-.__._----__--._.__c- - _ - - _ _ . - . _ _ _ _ _ _ _ _ - _ _ - _ _ - - - - - _ - - _ _ . . _ _ - _ . . . _ _ _ - . _ - -

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

- All efforts associated with OP 2310 were based on #012,#16, #19.1, - Upgrade OP 2310 to provide the following instructions for shutdown cooling initiation rather than plant cooldown 19.2, #20, #V23 the least experienced, qualified operator and ensure the SDC using T351Y with shutdown cooling in operation. and #37 System Engineer concur with these changes:[ Operations &

Technical Support]

• Sections for swapping heat exchangers and adding a second heat exchanger

. Instmetions for establishing PPC visual trends to monitor control parameters

- Develop a JPM for swapping and adding shutdown cooling heat exchangers.

- The amount of time to familiarize operators on the new #U Add a' briefing guide, similar to the type used for an IPTE, to SDC initiation process was too lengthy because all of OP 2310 to ensure the crew involved in initiating or securing the information was passed on in the briefing rather SDC is aware of the potential temperature transients, that than including steps in OP 2310. the goal is to cooldown or heatup without violating Technical Specification limits, what temperature sensors are used to determine cooldown er heatup rate, what temperature sensors are used to determine changes in cooldown and heatup rate limits and why they are different, and how parameters should be monitored during the process.

[ Operations]

5/13/96 32 Millstone Unit 2,2/22/96 Cooldown Event Review

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

- Operator familiar with SP 2602B upgrade issues was #13,#29,#30,and - Rewrite SP 2602B to incorporate lessons learned from the -

used as the only validator on the procedure #31 2/22/96 cooldown and validate the procedure on the modifications resulting in the following: a)some unclear simulator using a least experienced, qualified operator.

steps, b) difficult to use data sheets, and c) process did [ Operations]

not pennit timely feedback to PPO on cooldown rate ,

during transient conditions. i

- Include the following instnictions in the SP 2602B re-write: [ Operations]

. Definition oft.,

e When to start manitoring T351Y e How to determine one hour cooldown rate during transition from Tl 15/T125 to T351Y and vice versa

. Improve layout of OPS Form 2602B-1 by adding cooldown rate columns for both Tl15 and T125 so user does not have to perform mental calculation. .

- No formal training was given to operators on new #18.1 and #18.2 When formal training is not planned following a procedure revision of SP 2602B and only a verbal briefing on change, perform a more extensive verification and validation SDC initiation modifications. process on the modified procedure than required in DC 3 to

! ensure all steps are clear and achievable. [ Operations]

5/13/96 33 Millstone Unit 2,2/22/96  !

Cooldown Ewnt Review l .

4 i

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

- Evaluating the consequences ofchanging SP 2602B to #Z When lessons learned from the 2/22/96 cooldown are a 15 minute frequency was less than adequate since the incorporated in OP 2310, OP 2207, and SP 2602B, validate increased frequency caused the operator to invoke the procedures in the simulator with a full crew performing a additional conservatism with respect to cooldown rate. cooldown to ensure modifications to one procedure do not conflict with the objective or precautions of another procedure. [ Operations]

- Instructions defining Tm indicators were less than #AA Define T% for the purposes of cooldown rate limits, as adequate since information was not specified in follows: [ Operations]

procedures, training, or briefing. This caused conservative judgments to be made with respect to -The average of Tl 15, T125, TW11 IX, and TW121X when cooldown rate limits and the time Mode 5 was entered. SDC is not in operation

-The average of T351X and T351Y when SDC is in operation

- PPO had not performed a cooldown in the plant. #36 The following resolutions apply to causal factors #36 and

1. 37: [ Operations]

- Develop resources such as procedures, shift briefings, night orders, etc., for the least experienced qualified individual. In i the case of Operations, always assume the operator has never performed the task in the plant. OP 2310, OP 2207, ,

SP 2602B, and any PPC displays must be developed in accordance with this critena.

5/13/96 34 Millstone Unit 2,2/22/96 Cooldown Event Resiew ,

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

- Develop detailed shift briefing guides for cooldown, operation of shutdown cooling, and other seldom performed evolutions. These guides should be similar in nature to the IPTE briefing information and included in the affected procedures.

- Licensed operators are considered qualified for any #37 - Enhance standard shift briefing guide to add information control room tasks, although training and procedures regarding shift expectations when a visiting operator is may not support the least experienced operator. included in the crew. [ Operations]

- Periodically train tlte operatcrs in the simulator with crews  ;

containing one or more visiting operators to enhance team abilities under these unusual circumstances. [ Training]

- When a high risk evolution is going to be performed and the board operator is inexperienced on the plant, the Shift ,

Manager should provide an increased level of oversight to ensure that the evolution is being effectively performed.

IOperations]  !

- When an inexperienced operator is going to perform a high risk evolution, the Shift Manager or SCO should emphasize i during the briefing that crew members with experience should support the inexperienced operator and maintain effective communication during the evolution. [ Operations]

5/13/96 35 Millstone Unit 2,2/22/96 Cooldown Event Resiew

i t

P Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart bhu asuahwauud%iskhuwakuuman caubusua.iAauamuuksskn$1di&EllikhcdLablEl%d5% {

• PORC review of changes to cooldown process was less than adequate.

- PORC was disorganized. #14 Establish an agenda (written or verbal) at the beginning of a  !

special PORC session to ensure everyone attending is i onboard and has all necessary resources available to participate. [PORC Chairperson] '

I

- There was an urgency expressed during PORC to #15 - When a solution to a problem involves revising procedures, approve the procedure so cooldown could commence. as well as obtaining other information or hardware, consider  !

holding PORC on the revised procedures as soon as possible i to provide a better opportunity for evaluation by PORC and time to make modifications. PORC has always provided a mechanism to approve procedures pending incorporation of f info or completion of related woric. [PORC Members]

~

i.

- Establish a process for requesting and evaluating Technical Specification waivers deemed necessary for the safe l operation of the plant. [ Licensing]

- RCS and SDC System engineers did not attend PORC. #T17 - Include RCS and SDC System engineers in the review  !

process for OP 2310, OP 2207, and SP 2602B.[ Operations] [

l

-When procedure changes have been rapidly processed to support resolution of a problem, include affected system f engineer in the PORC discussions to ensure the engineer is  ;

aware of the procedure changes and to request an opinion of  !

these changes. [All Department] [

5/13/96 36 Millstone Unit 2,2/22/96 .

Cookkmu Ewnt Review I d e

?

i

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart ha a h a aAAu;na h m uas e # wa=Aua.naamA baa mansmO$s3M hamw=addi b-ad!

. Shift decision making process for adding second heat exchanger less than adequate.

- Shift perceived cooldown had stalled, although #30 and #31 Provide a trend of temperatures and flows to assist the cooldown rate was between 12*F and 18 *F per hour. operator in controlling and monitoring cooldown rate, SDC flow, and RBCCW flow through the SDC heat exchangers. i Have the display (s) evaluated by a human factors engineer l and validated on the simulator while a complete operating .

crew is performing a cooldown. This will ensure usability, understandability, andjob compatibility associated with the l' PPC modifications.

[ Technical Support, Computer Services, Nuclear Safety]

- Shift decided that their recent experience gave them a #32 Provide the following to ensure all crews feel equally better chance for success in adding second heat qualified in performing initiation of SDC:

exchanger than a new inexperienced crew. Knowing what had happened to the cooldown rate with the - Add a JPM specifying that simulator training must include addition of the second heat exchanger, the subsequent initiation of SDC, adding a SDC heat exchanger, and i I

crews chose to take local control of RBCCW flow and swapping heat exchangers. [ Training l throttle the RBCCW flow as heat exchangers were added or removed. - Provide the level of detail in OP 2310 to ensure an operator ,

with no plant experience associated with the initiation and subsequent operation of SDC will be comfortable with performing the evolution. [ Operations]

t

- Shift considered plant " unstable" with cooldown stalled #33 The resolution to causal factors #30 and #31 above should assist the operator in determining whether the plant is stable i and the next shift unable to take action until after shift briefmg. The plant was actually stable. during SDC operations.

5/13/96 37 Millstone Unit 2,2/22/96 Cooldown Ewnt Review

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

- Shift objective was to minimize the amount of time #34 - Since operators are trained to avoid violating Technical Technical Specification 3.0.3 was exceeded which Specification, communications must be clear, preferably in placed a selfimposed time pressure on reaching night orders, exactly what is expected when a Technical Mode 5. Specification must be violated to ensure more critical Technical Specification is not. Specifically, provide guidance indicating the priority associated with Technical Specifications 3.4.9.1,3.0.3, and 3.4.1.3.

[ Operations]

- Conduct operator training on non-routine decision making capabilities. [ Training]

38 Millstor.e Unit 2,2/22/96 5/13/96 Cooldomt Event Review

Y t

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart

. m , . . .. -

m m. r u m m., , , , ~ s  % - - .

I MNkNh-

- IU k' db - k 5 -k :b h "

b ) b 5. ^~

wk 8 .

k C . ' . f Ed N '."$' f.- . kv[ . E. ,

. Operator skills required to maintain an acceptable cooldown rate during the addition of the second heat exchanger less than adequate.

- PPO asked the operator he requested to monitor the #38 The resolutions previously specified for procedure cooldown rate trend to indicate the direction of modificatic ns, training enhancements, and PPC capabilities temperature change, not the amount of the change. also apply to causal factors #38, #39, #40, and #41.

- PPO did not move pre-established visual trends of #39 T351Y temperature parameter to CRT on PPO's desk. 1

- PPO used digital shutdown cooling flow values to #40 establish a specific flowrate and then fine tuned the adjustment in response to the temperature change indicated by T351Y, SDC to RCS temperature.

I

- PPO attempted to re-establish an earlier cooldown rate #41 rather than stabilize temperature following the addition .

of the second heat exchanger.

t 39 Millstone Unit 2,2/22/96 5/13/96 Cooldown Ewnt Reviev

. - - - - - - - - - a,_- - --a - u_- . . . - - ,------_---------,----__--___._---------u-----________----_-,,-------_---_--__a. - - - - - - - _ - - - _ . - - - _ - - - - - - - - - - _ . . - - - - - - - - --

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart b L k s m e d $il d i k a m a h d a n m a n $ h a d $l d i hia ikb 5 E b u s k d E id $ 5 $2 0 0 d $l5f0 E$I$$$ $$ u Si$ b 5 G 5 E E $

e Controls specified in OP 2310, " Operations of Shutdown Cooling System," and selected by shift were less than adequate for adding second heat exchanger and maintaining acceptable cooldown rate.

i

- SI-657, SDC System Hx flow control, is very non- #W24 Causal factors #W24 and #X25 do not require rerolution as linear over it's operating range making it very difficult long as the procedure, training, and computer modifications to perform precise or fine adjustments. The operating ensure that SI-657 is not an operator work around during band, which provides the best results, is approximately initiation and operation ofSDC. Otherwise consider 5% to 30% demand. redesign of SI-657 for better flow control and of RB-13.I A and B to permit throttling RBCCW flow to the SDC heat exchangers from the control room. [ Design Engineering]

- A delay time exists between adjusting SI-657, SDC #X25 System Hx flow control, and seeing the results of the change on T351Y, SDC to RCS temperature. This results in a more conservative cooldown rate and a longer time to achieve that rate since changes are made in smaller increments.

r 5/13/96 40 Millstone Unit 2,2/27J96 i

Cocidown Event Review

Root Causes & Associated Causal Factors Number on Recommended Resolution (s) for Each Causal Factor E & C F Chart ex;ianis@$aia: aMaaacuAasaansa.sneaumamumamafe~ - - bdaEamasadsstandaaauma.maiusdJ

. Visual trends provided on the PPC were less than adequate for adding second heat exchanger and maintaining acceptable cooldown rate.

- Visual trends needed by PPO to monitor cooldown rate #39 The resolutions previously specified for upgrading PPC ,

were located on Shift Manager's CRT which is many capabilities (displays and location of CRT displaying feet from the SDC controls. information) also applies to causal factors #39 and #40.

- PPO had digital displays for shutdown cooling flow #40 information located on display "SDC" at the C04 CRT rather than temperature trend data.

i 5/13/96 41 Minstone Unit 2,2/22/96 Cooldown Event Resiew 9

.a .-. - - _ .--_ . . _ - _ - _ - - . _ _ . _ _ --- - - -

l

. 7.0 COMMENTS 1

i The following information was outside the scope of the event review but was identified j during the review process and was considered noteworthy by the ERT.

i Item A The ability to operate an RCP during SDC operation would greatly reduce

the probability of exceeding heatup and cooldown rate limits. During RCS i

cooldown, the one hour natural circulation limit would no longer be a factor j and the downcomer temperature during SDC initiation would be represented -

! by T115 and T125 due to ensured mixing. During RCS heatup, the increase in downcomer temperature would be reduced since the temperature increase l

l. incurred during the time SDC is secured and an RCP can be started would i be eliminated.

i Item B Discussions with personnel in Nuclear Engineering indicate the possibility of

, increasing some of the heatup and cooldown rate limits. In particular, the j

5 T cooldown rate limit required below 120 T was discussed. Although i certain tradeoffs, such as reducing allowed maximum RCS pressure with a higher limit, are required, the benefit of easing operating limits during

! transient conditions and thereby minimizing exceeding Technical I' Specifications seems worthwhile.

1 t

l l

l l

5/13/96 42 Millstone Unit 2,2/22/96 Cooldown Event Fesiew J

8.0 ATTACHMENTS 8.1 Shutdown Cooling System - RCS Penetrations Versus Locations of T351X and T351Y 8.2 Major Coolant Flow Path 8.3 Event and Causal Factor Chart 8.4 Barrier Analysis Chart 8.5 Change Analysis Chart 8.6 RCS Cooldown Curves 8.7 RCS Cooldown Data I

l l

-5/13/96 43 Millstone Unit 2,2/22/96 -

Cooldown Event Review l l

T351Y Upstream of These Nozzles RP

"[# SDC Discharge Rx , S/G #2 S/G #1 y,,,,g i

=c IB N SDC Discharge / -

(

T351Y Upstream of "Ihese Nozzles T351X O

SDC Suchon Attachment # 8.1 Shutdown Cooling System - RCS Penetrations Versus Locations of T351X & 351Y 5/13/96 1 of1 Millstone Unit 2,2/22/96 Cooldown Event Review i

_ _ _ . _ _ _ _ _ _ _ . _ . _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ . _ . _ . . _ . _ _ _ . . . . _ . - _ _. . . _ . . ~ .

l

.. . Attachment # 8.2  !

I VESSEL i

i T351Yis upstream of the SDC During operation i discharge header of SDC, T351X i andis the most ,

is representative I

> representative of j of the loop 2 hot downcomer i leg temperature.

temperature during _ . <

SDC oneration. I

] . N VESSEL

}- INLET FLOW 5 OUTLET NOZZLE N0ZZLE

]l I -

m ., - m ,, m

[

l '

ll ,

INLET PLENUM

{

REGION o L

U' 11 INLET PLhNUM i; e REGION ii 11 FUEL ASSEMBLY AND GUIDE TUDES ll 1l l

~

l1 lI

ii ,

EFFECTIVE FLOW g iI FOR HEAT TR ANSFER N I )

\ N y 5pm 11 l

a o e ,

9 1

, i

. j I

s -

1 -l J l i l

MAINS FLOW MAJOR COOLANT FLOW PATH 5/13/96 1 Millstone Unit 2 Cooldown Event

l Attachment # 8.3 ,

I r

[

f I i

i I

f

+

EVEST AND CAL SAL FACTOR CHART 1

t 5/13/96 Millstone Unit 2,2/22/96 Cooldown Event Review t

, Event and Causal Factor Chart Key -

SYMBOLS Acronyms C - Computer Date Source of data Date Source of data 1 - Interview Undesirable b -

E Event RCP - Reactor coolant pump '

Condition S - 2602B-1 Surveillance Data Sheet SDC - Shutdown cooling i

Contributing Factor B Broken Barrier U""

Procedures Causal Factor for T.S. 3.0.3 OP 2207 - Plant Cooldown r OP 2310 - Shutdown Cooling System Number SP 2602B - Transient Temperature, Pressure Causal Factor for ,

T.S. 3.4.9.1 Letter & Number Causal Factor for T.S. 3.0.3 and T. S. 3.4.9.1 5/13/96

. ._ . _ . . _ . ._ -._ . . _ . _ _ . . . _ . _ _ . _ . . . . _ _ _ . _ _ _ . . _ . _ _ _ _ . _ ___...m. _ _ . . . . . .

4

1. 2 Stress Analysis - Berlin did not provide feedback to thermal" striping" issue 5_

Based on RCS training info, II U Operator asked ops Technical Support #I l EngineeringSupervisorwhy investigation focused on RTD No urgencyat time of request j T351X, RCS to SDC temperature, mos' representative of RCS since cooldown not identified was monitored for temperature during SDC as a problem.

heatup/cooldown. operation.

9/3064 V I 10/1164 V I 6/23B5 I 765 I 765 1f I R.E. Supervisor, Technical SDC System Calvert Cliffs Engineers Control Board ops Engineering Supervisor Support notified ops Engineer reviewing speak to ops Operator discussed 4 sent memo to R.E.

Supervisor, Technical

+ Engineering Supervisor cooldown data for 4 Engineering Supervisor + desire to run RCP with ->- !  !

by memo, dated 10/1164, that SDC heat exchanger about running RCPs SDCwith RCS System Support asking whether Engineer. Request T351X, RCS to T351X, RCS to SDC transients. with SDC, since their not given high priority.

SDC temperature,or temperature,was the correct plant does this.

T351Y, SDC to RCS sensor for monitoring heatup/

temperature, should be used cooldown rate.

for cooldown rate determination during operation of SDC. t P

l e

i 5/13S6 Page 1 I

I I I I I I 2/14 2/15 2/6 I I I I I I

1. C58 m #A3 l #B4 l I Operations notified of Start of work on No one questioned l l Heatup ERT Team cooldown issue to assist m cooldown was dependent need for Adverse Leader scheduled to determining degree of urgency on completion of heatup Condition Report at l l l be out of the office -

regardmg cooldown mvestigation by Event this time. 2/19 - 2/25.

heatup effort. eview Team.

l l l Late January l l l I ~ 2/6 y ~ 2/6 I 2/14 V I 2/15 y I 1996 U 1 Heatup Event Review IIcatup Event Review Operations ops Manager, ops Heatup ERTTeam Team discussed the need personnel Assistant Manager, lm leader requests 4

Team discussed likelihood that T351Y, l> to start lookingat > discussed revising OP 2201 and l> Unit 1 Restart ~v Technical Support Y RCS to SDC cooldown. Team Leader l Manager, and ops l consultant to l agreed that Operations SP 2602B. Consultant had a initiate data temperature,would ops Procedure also affect cooldown. l personnelsupporting the l meeting. Identified I gathering for ERT would start Writer starts draft cooldown i cooldown events, Unit 2 Director i verbally notified of I looking at cooldown of heatup l problems and I follow-up with Procedures. changes. l. the need to use l Supervisor, potential cooldown i I I T351Y, SDC to I Structural and issue.

RCS temperature, Design Support on -

l l during SDC l 2/20, discuss data operations. with Supervisor, l l l Safety Analysis l l' duringweek of l 2/19 - 2/23, and l l obtain RCS l

cooldown data from

-l l .l SDC System Engineer for 12/95 event. .

5/13/96 Page 2

Supenisor, Safety Analysis,was not given a desired completion date for providing l equested data.

I l

2/16 I 2/19 I 2/20 v

l Meeting took l place prior to shutdown i l l notification, thus urgency I was only placed on need I l l for Appendix G engineerin evaluation.

l l -l 2n0 2/16 I 2/19 I 0930 I ~ 1530 y I 1815 L 1854 L l l Supenisor, Results of Meetingwith Meeting between Entered TSAS Commenced Structural and Appendix G l Manager, Technical Supervisor, Structural and 3.03. HPSI boration of 4 Design Support, l> analysis Support, RCS System -> Design Support, RCS System 4 injection valves --> RCS. 9 given cooldown l completed l> Engineer, and Engineer, and Technical Support Consultant.

declared INOP.

data from 12/95 g and results l Technical Support SDCinitiation. I satisfactory. 8 Consultant. Discussed Notified site that 12/95 Expected past cooldown rate cooldown transient analyzed completion of l l problems and on 2/19 was acceptable, OA on Appendix G assigned lead to calculation not completed.

l l Asked Supervisor, Structural analysis on RCS System Engineer.

temperature spike l WritingAdverse and Design Support,if spike 3 l can be ignored in all cases.

on 2-19. Condition Report l assigned to Technical Supervisor, Structural and l Design Support, discussed IL Support Consultant.

l need to clarify Tech. Spec.

l Basis; Supervisor, Structural l l and Design Support placed call i Supervisor, Safety to Supervisor, Safety Analysis Analysis notified of same l l for input. Data was requested.

problem earlier m week i l Supervisor, Safety Analysis by Heatup ERT Lead. l I said he would look into this.

No calculations requested at that time.

5/13/96 Page 3

1. D6 pr7 Requested not to Cooldown changes submit Adverse to SP 2602B not Condition Report addressed by Heatup until verification of Event ReviewTeam.

cooldown data.

2/20 V V w

Completion of Ifeatup changes to Request based on Adverse Conditionrieport SP 2602B recommended need to shutdown was needed to sur port in memo TS2-96-088, No procedure writers plant and cooldown decisions on pending working mid-shift.

dated 2/7/96.

to MODE 5. lant shutdown.

~ 2030 1 I I I Supenisor, 2100 V I 1900 y 2000 y 2000 V Structural and 2050 1 Manager, Technical Adverse Condition SP 2602B being Received official Left message Design Support Support requests Report on past cooldown marked up to use and Technical copy of engineering for ops Dept.

--> Supenisor, Electrical > rate violations, not spike -> T351Y, SDC to 4 Support + evaluation + Procedure +

S; stems to have lead at SDC initiation, RCS temperature, Consultant performed by Safety Coordinator on cooldown submitted to Shift for heatup and Analysis to satisfy to resiew and further discussed issues. Manager. cooldown. possibility of Tech. Tech. Spec. 3.4.9.1, incorporate jk Spec. clarification Pressure / mark-up to j(

Temperature Limits, SP 2602B.

for dealing with T351Y, SDC to Reactor Coolant RCS temperature, System.

1 Supervisor, Structural and Design Support, completed spike at SDC OA of calculation for Supervisor, Electrical initiation.

i engineering evaluation 1 Systems directed required by Tech. Spec. '

Operations Consultant to ,

3.4.9.1.b. Aware of plant draft changes and review shutdown. with Technical Support Consultant 4k /

1. E Technical Support Consultant expected spike j at SDC initiation to be a non-issue due to discussions with Supervisor, Structural and Design Support. Page 4 ,

5/13/96

...---, - ... ----- - - - - - ' " " ' " ^

~

i L

I 2/20 l 2/21 I

I In shift turnover

[

SCOs discussed status No calculations 8 j of procedure changes. l or SDCissues SCO told procedures were addressed. l not being worked on  ;

midnights. l.

l M1 2207 L 2210 L 2216 L 2300U I 2300 V .2335 L 0100 L  :

Entered Mode 2 Turnover Entered Mode 3 l

Plant off Fire in Supervisor, guidance from flot Standby, Entered line. CO8R, startup, Safety Analysis

+ + main -> RCS Temp.532*F -> SCO: -> notified by --> RCS Temp.532'F r

OP Plant 2207' Coo ld""-

transformer RCS Press 2250 Cooldown but Design RCS Press 2250 l 86 lockout Power s 5%. don't go on Engineeringof GEA GP 4 at 72 relay. SDC- plant shutdown steps. l N and possible need for help l on HPSI Prior revision of Operability l SP 2602B performed problems. smce new procedure l not completed.

E

1. G l Supervisor, Safety Analysis did not knw l Previous revision about the 37 hour4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> time ' of SP 2602B considered constraint to get to I satisfactoryforcooldown j MODE 5, cold l rate calculations with j  !

shutdown.

RCPs operat /

5/13/96 Page 5 l

t

V a

t i

2/21 i

Computer Board Operator had I previously l incorporated heatup modifications.

0144 L 0150 'L ~0500 I 0500 V I ~ 0700 I 0709 L 0712 L Started SDC ops Dept. ops Dept. Entered Mode 4 Shifted Steaming Secured Cooldown 1i"*"p activities Procedure A RCPs 4 commenced. A per OP Procedure 4 Coordinator 4 HotShutdown'300 RCS Temp. < A F to atmosphere A A and C.

• Coordinator dump valves.

Plant Cooldown, continues work gave draft RCS Press.361 psia on SP 2602B. procedure with changes to Operations Consultant.

i t

5/13/96 Page 6 -

1. K -

Call wEs not made the evening before .

because thought a success path existed.

2/21 Appendix G calculations are not U

used to clarify Tech. Specs. Limiting condition of operation requirements, Operations Manager called Supeivisor, Safety Analysis I (e.g.cannot use Appendix G results l to ensure SDC initiation to write clarification saying it is ok to spike aggressively being exceed 30*F/hr cooldown during pursued and no safety SDCinitiation). analysis concerns.

j

~ 1000 I

~ 0830 I ~ 0900 V I ops Assistant 1000 V I ~ 1000 I ~ 1000 I Discussion between Discussion between Manager discussed Operations Maintenance Operations Manager Techmcal Support Techmcal Support SDC initiation and ops Assistant Manager Manager, ops

-> Consultant and A Consultant and Supem,sor, -> temperature rpike -> Manager discussed -> discussed Tech. --> Dept. + '

Manager, Technical Structural and Design with Supenisor, Specs.with Procedure concerns regarding Coordinator, Support. Could not accept Structural and Design Supervisor, Support about SDC SDCinitiation Structural and Control irutiation success paths Tech. Spec clarification Support. Told further temperature spike discussed with about tolerating a spike calculations required. with Supenisor Design Support. Operator, ops Assistant and Operations Supervisor, Structural during SDC initiation .. A Safety Analysis Manager Consultant and Design Support unless supported by mixmg on 2/20. analysis or licensing ^ h requested 70'F review mterpretation' test case and SP 2602B.

ops Assistant Manager Requested Supervisor' letter covering informed Appendix G test case.

Structural and Design calculation could not Support obtam mput frorn #I cover SDCinitiation- 'upenisor, Safety Analysis Supemsor, Safety Analysis.

TechnicalSupport understood he needed to analyze Supervis r,S fety Consultant agreed to speak mixing issue to write off spike and was Analysis pursumg natural with Licensing. aware of issue through discussions with circulation AP approach.

Heatup ERTTeam Leader on 2/16 and Supervisor, Structural and esign Support an 2/20. g Supenisor, Safety Analysis y contacted Yankee for input in a.m.

Did not have desired info. Pursued

1. 3 Electric Power Research Institute l ops Assistant Manager reports for calculation data. Required a number of hours to identify and not made aware of time necessary to obtain locate design info. during the morning.

industry data.

5/13/96 Page 7

2/21

1. L8 ~

7 #M9

[ Decision not to pursue, , Not apparent to

[ waiver due toinformation Operations who to call that there was a good for support with probabilityof HPSI cooldown issue. 1230 I erability. SP 2602B resiew team met to

~ 1000 I ~ 1130-1230 I 1220 L ~ 1230 V I ~ 1230 V I $**r"" f action.

Started A and B ops Assistant Maintenance Manager, Technical Comments from Meeting between LPSI for Manager telephoned Manager, Support notified by 1000 review were V.P. of Operations, Unit 2

+ -> SDCboron -> Director, Operations -> Af anager, Technical -> Operations y

-> Technical Support incorporated in Supp rt and Consultant, Consultant success SP 2602B. equalization. Manager, Ops Engineering requested assistance Supervisor, path suggested by Supenisor discussion on with cooldown issue. Electrical Systems, Supervisor, obtaining waiver to stay in Manager, Technical and ops Dept Structural and MODE 4 from NRC.

Support indicated Procedure Design Support on inability to provide Coordinator 2/20 may not be short term guidance. discussed RBCCW satisfactory, g flow setup in OP 2310. No changes made to OP 2310.

Told ops Assistant N Manager that Supervisor, ggy Electrical Systems had lead Decision that until for Tech. Support. training could be j conducted, the fewer procedure changes made.

Operations did not #NIO would be best for require Engineering o rators.

to lead cooldown effort. 3 T

1. 012 OP 2310 review focused on SDC initiation.

5/13/96 Page 8

1. P -

Approach to solve T351Y, SDC to RCS No success path for temperature, spike at Rewording ofvarious any flow rate, using SDC initiation not SP 2602B procedure natural circulation clear- steps identified. AP approach.

2/21 V

Y #R V -

1. 13 No success path Natural circulation available with current Operations validator participated in AP approach pursued approach. Modification of OPS Form 2602B-1 portion of procedure ,from early to verification. mid-morning until was required. this time.

~ 1300 V I ops Asistant 1400 V I 1430 L ~ 1500 V I 1530 V I 1600 I Validation of ability Supervisor, Safety Table top review SDC system at Nuclear Licensing u n r' Safety to do OPS Form Analysis specifies of SP 2602B. Need 2143 ppm requested by 4

Analysis further discussed needs to + f r additional --> boron > 2602B-1 in less than --> to OPS Assistant 4 Technical Support +

changes to SP 2602B concentration. 15 minutes. No Manager that no Consultant support cooldown. further procedure clear success path identified. Discussed to initiate Tech.

Information changes requ, ired. exists for AP mixmg Spec. clarification requirements bility toleave OP 2310 as written since SP 2602B ready for calculation. of 3.4.9.1.b.

clarified by ops PORC. Operations sent pesired method of Pressure /

Assistant Manager. ,

plant data to .

imtiating SDC was Temperature Limits.

Ik within current Supervisor, Safety Analysis to show pq procedure scope.

Option to use Tech. P. st natural circulation.

Spec. 3.4.9.1.b.

Pressure / Temperature jk Limits, action statement not considered.

Supervisor, Safety JL Analysis needed SDC System volumes. /

Personnel focused on mixing calculation to avoid entering action statement.

5/13/96 Page 9

t I

t t

2/21 Atmospheric dump 1st approach not valves fullopen.

achievable. [

f l ,

1600 I Between  :

Operations Consultant, 1700 V I 1750 L 1900 -2000 I 2000 V C  ;

ops Assistant Manager, Supervisor, Elstrical Commenced Supervisor, Safety Analysis Cooldown  !

and Operations Manager Systems and warm up of SDC decided results using natural stalled at ' i

> called Supervisor, Safety 4 Nuclear Licensing --> system. ---> circulation and available r

260 F-Analysis back. initiate 2nd Tech. Spec. industry guidance were not 7 ops Assistant Manager clarification. conclusive. Started pursuing suggested 100 gpm per loop mixing model for existing until cold water swept out of plant AT and decay heat. ,

SDC System. g dk [

Supervisor, Safety Accurate plant data  ;

Analysis still analyzing available for this ;nodel mixing calculation based but model only good for  ;

on naturalcirculation AP this one c _se.  ;

approach. r Jk i

Jk I

Tech. Support supplied Operations concern current plant data for  !

whether cold water would '

mixingcalculation.

l be swept out and mixed }

within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Tech. Spec.

window using100gpm method.

5/13/96 Page 10  ;

t

1. 15 There was an urgent need to accept procedure No agenda specifying changes and Tech. topics or presenters.

l Manual clarification so implementation could gy occur promptly.

]B Basis for Tech. Spec.

3 A.9.1.b. Pressure Temperature Limits,

1. 14 l clarification changed during Approval obtained over telephone. No PORC was PORC to "one time use only" for currentplant OP 2310 directs flow procedureswere disorganized. setup of 1000 - 1500 faxed to Safety condition.

epm.

Analysis approvers. _

m Questions at PORC 2100 V '

2130-2150 V I among presenters- 2315 V L Obtained techm, cal Set "A" RBCCW approval from Supervisor, PORC of OP 2310 flow to "A" SDC p  %

m

- Structural and Design > SP 2602B and Tech.

Spec. clarification.

Heat Exchanger Support and Supervisor, at 1010 gpm and Safety Analysis for then isolated.

procedure changes to jL SP 2602B and to initiate SDC slowly. Supervisor, Safety Analysis requested 'ORCwas originally change to OP 2310 to scheduled at 1630 but pause duringinitiation of delayed due to HPSI valve RCS and SDCSystem SDC to equalize Engineers did not #16 operability evaluation m temperatures.  !

incomplete. Additional

' attend PORC meeting since they were not j( PORC delays while waiting nvited.

for operability report and mixing calculation.

Flow calculation to accept T351Y, SDC to I.k RCS temperature, spike at SDC initiation were only valid for SP 2602B was not shutdown on 2/22. PORC'd earlier because I mixing calculation for Tech. Spec clarification was not finalized.

5/13/96 Page 11

1. S PORC agreed cooldown l should start on third shift. -

I Members believed enough time was available to The prioritization successfully complete between these Tech. cooldown to Mode 5 by l 0715.

Spacs was made at PORC. l 2/21 2/22 l

v l Interpretation of Tech. y Spec. 3.03. bases and action Since Operations did l requirements for Tech. Spec. not know how long before T351Y, SDC to RCS Tech. Spec. Data obtained from 3.53 occurred between l l clarification was not operator developed Operations Manager, LOIT, temperature, equalization, visual trend on ops Assistant Manager, Shift this information was needed l meluded in brief.

if hour was coming to SPO CRT.

Manager.  :

- an en l 1350 y I ! 0015 - 0115 y I 0100 y S 2324 L 2300 - 2345 L 2330 V L Set "B" New time limit Shift brief. Shift l Operations Control Operator RBCCW flow to applied for Tech. Manager informed Consultant brief starts OPS Form

--> "B" SDC Heat --> Shift turnover. + Spec. 3.03. > crew TSAS 3.4.13.b l

> on OP 2310 and > 2602B-1. >

Exchanger at Requirement to coolant loops and I SP 2602B changes.

1015 gpm and reach Mode 5, coolant circulation I Hot Shutdown, one hour time limit 2k jk then isolated. l verified to be would not be 1 0715. exceeded regardless

1. 18 I gg oftemperature l equalization Crew members indicated No formaltraining following initiation l they had not used or even on newrevision observed T351Y, SDC to l-of SDC. of SP 2602B.

jg l! RCS Temperature, during previous initiations of l SDC. Told to do bestjob hey could.

l No discussion about possible Tech. Spec.

l 3.03 exceedence.

l Page 12 5/13/96

Changes for initiating  ;,

3 3,7 SDCwere not included recommended pausm.g as stepsin OP 2310 I after opening each SDC I injection vahe tolet mixing occur.

Y 2/22 #U Lengthy time required to lI brief crew on changes to SDC initiation delayed start of Operations Consultant cooldown from Mode 4 to briefinstructed operators Time between brief and Mode 5. to pause between opening ,

each valve and to use as securing RCPs normal due crew preparation much of the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> natural requirements. circ time as needed for mixmg.

0115 - 0130 1 0151 y L 0152 L 0200 L 0207 L 0208 1r L Shift brief on SDC Secured "B' Plant Equipment RCS < 265 psia SI 709, SDC Throttled open l

initiation. and "D" RCPs, Operator began Opened SI 651, System Suction SI 615, LPSI 4 Briefincluded:

m

- Entered TSAS -> manually opening 4 652, SDC Y IIcader Isolation U Injection Wlve U

-Review of OP 2310 3.4.1.3.b., SI 709, SDC System Suction Open. Loop 1A, to Ifx)

-Review of CP 2207 coolant loops - System Suction System Isolations. gpm.

-Expected difficulty and coolant Header Isolation.

circulation. Jk controlling temperature.

Crew knew they could achieve 1000 gpm easilyif1 hour Shift Manager's time was running decision to use both out.

heat exchangers based on 12/95 cooldown I

experience.

Previously achieved 1000 gpm within a few minutes.

5/13/96 Page 13 -

, - . . . - . . - . . _ . . . - . - - . . . _ - - . . . ~ . . _ . - _ . - . . . - . . . . . - . . _ . . _ .

t 2/22

1. 19.1 Operator used 32 RBCCW vahr opened minutes to initiate from Control Room per SDCin accordance with OP 2310. No throttling briefinginstruction to capabilities available from ensure mixing. control room.

0240 V UC 0256 y C 0216 L 0221 L 0228 L Out of TSAS 3.4.1.3.b, RBCCW flow to Throttled open Throttled open Throttled open ,A'SDC Heat SI625,LPSI SI 635, LPSI coolant loops and m SI 645' LPSI  ; Exchanger p Injection Valve U Injection Valve  ? Injection Valve  ? coolant circulation SDC

> 1000 gpm. tablished at Loop 1B,100 I.aop 2A,100 Loop 2B,100 gpm. gpm. gpm.

5/13/96 Page 14

Shift Manager gg specified using 2 heat ncreasing frequency PPO could not establish of SP 2602B to every 15 exchangers based on steady cooldown rate.

minutes caused PPO to Maintained conservatiw 12/95 cooldown be more conservative experience rate to ensure limit was not cooldown rate e, Hed V

2/22 V #Y26 OP 2310 specifies Crew unfamiliar with setting RBCOV flow

' tablishing a steady T351Y, SDC to RCS between 1000 gpm cooldown rate using Temperature, response and 1500 gpm.

T351Y, SDC to RCS temperature,was difficult I during SDCoperation.

with S1-657, SDC Control Operator

1. 20 system Hx Dow control. suggested raismg RBCCW V

1. X25 temperature so PPO could Based on East i

take larger swings on [ Inability to control

• P SI-657, SDC system cooldown with 2 IIcat Delay time exists between deca dt va in lix flow control valve. Exchangers m, adjusting SI-657, SDC sernce due to excessiv second heat exchanger I system Hx flow control, and RBCOV flow.

seeing final result T351Y, SDC to RCS Temperature.

0300 V C 0300 - 0430 y s/ 0315 V I 0320 V C RBCOV flow Cooldown rate well SCO and Shift Manager "B" RBCOV below30 F/Hr.

' to "B" SDC heat exchanger m

- Cooldown of 14'F m

r discuss raising RBCOV > flow isolated to A temperature control *B" SDC Heat established at between 0300 and 0400.

valve settings versus Exchanger, 1000 gpm Cooldown of 11*F between 0400 and 0430. _

isolating RBCOV from ne SDC heat A Procedure OP 2310 exchanger. Decision to specifies use of SI-657, SDC

[T351Y,SDC to RCS#22 #21 system Hx flow control, to is late ne SDC heat exchanger.

Temperature. response m/ [ Crew had not regulate SDC flow through on simulator not the practiced cooldown on the heat exchangers same as the plant. simulator using T351Y, q SDC to RCS mperature.

1 I-657, SDC System #W24 g " #

Personnelinvolved in T351Y, SDC to cooldown process changes non-linear ovei its operating RCS Temperature, much { band. Very difficult to throttle were not directed to evaluate impact of T351Y > m re responsin to SDC flow when valve demand System changes smce it is indicated less than 5%.

on whole process rather I cated at the discharge of than only SDC initiation.

the heat exchangers. '

Page 15

<t12/06

Shift Mareger selected T351Y, SDC to Cooldown rate limit RCS Temperature, as basis previously based on '

T351X, RCS to for cooldown rate limit since most conservatne. SDC temperature.

s 2/22 Y

1. 18.2 Shift conclud Raised RBCCW Shift Manager selected No formal training they probably would temperature to T351X, RCS to SDC or hands on experience not make 200*F by 72*F based on Temperature,as basis for prior to using revised 0715. past expenence- mode change since most SP 2602B. conservative.

Y V V Y -

1. AA Shift Manager wanted Plant Equipment Observed use of input from DSEO regarding Operator suggested Procedure presided OPS form 2602B-1 at possibility of violating either raising RBCCW no clear direction 0315 entry on data Tech. Spec. 3.0.3 or 3/4.4.9. temperature. on instrumentation sheet. Pressure Temperature Limits to use for T,yg.

0330 V I 0423 V I 0430 V L 0445 V L Control Operator starts "A" and "C" RBCCW ' n'3 at 720*Fon OPS Form 26028-1, Shift Manager temperature control T351Y, SDC to

> Tiransient Temperature Pressure > called DSEO t > valves raised from 68*F to > RCS 'Ihmperature. +

Verification Data Sheet. Relieves Control Room. 72*F to place S1-657, Reduced cooldown Control Operator. SDC system Hx flew rate to 20 F/hr g control valve,in better per OP 2207, operating range. Plant Cooldown.

Data obtained from N operator developed visual trends on CRT Control Operator OPS 2 SPO desk. #28 showed completed 15 minute Discussion between SCO g calculations to PPO. Provided and board operators on i

PPO with verification of cooldown  ! throttling RBCCW to SDC l

~

rate. PPO used separate visual heat exchangers and raising Cooldown data trend on OPS B CRTon RBCCW temperature.

recorded and evaluated Shi't Manager's desk.

in less than 5 minutes.

A Split AT col #29

1. 27 on PZR form to Shift Manager decides Recognized data on permit easier data on adjusting one sheet being placed in comparison.

parameter at a time.

wrong location.

5/13/96

O 19.2 Decision to throttle back Procedure only has steps SI-657 SDC system Hx

1. 32 for controi room opercted Shift decided that previous night's flow control vahr. then ' RBCCW vahes which are experience versus new on coming cut in RBCCW flow t full open/ full closed type.

shiftsinexperience withT351Y, B" SDC heat exchanger.

SDC to RCS Temperature response, gave them the better chance for g success in performing tl is ulution. #33 Discussion about not Shift decided plant was turning over until more s not " stable" at current 2/22 '

1. 30 heat removal capability cooling with I heat was established. exchanger.

PPO perceived the cooldown had stalled.

A I #31 Further opening of Decision made by Supervisor, Mechanica SI-657, SDC system Hx Systems requested SCO to increase heat 2 I fl wcontrol,hasinglittle input from Operations removai capability by adding 2nd heat I"P. ct on maintammg Manager regarding desired cooldown rate.

pec. violation exchanger.

~ 0445 I ~ 0410 V I 0655 I 0655 V S/C 8hi "8 Call to Operations Manager PPO asked CO to "B" RBCCW flow to "B" SDC heat D5 di sible

+ . Tec +

to discuss possible upcoming Tech. Spec. violation. +

monitor cooldown temperature on OPS B Y

exchanger established between 0 to 900 gpm.

SDC flow through the heat exchangers was m

7 i t n and n o OPS Manager directs not to CRTlocated on Shift cutin half to reduceimpactof addingsecond define Taygfor MODE exceed cooldown rate. heat exchanger.

Manager's desk.

change during SDC oneration. Ik Ak Discussion about throttling RBCCW to T351X, RCS to SDC "B" SDC heat temperature,was used exchanger.

previously for determiningT,y for MODE change during SDC j operation. OPSform 2602B-1 jL no longer logged T351X, RCS to SDC temperature. Shift felt they could 1) increase heat remova? #34 by adding a second IIx and 2) j minimize impact of second Hx by throttling SI-657, SDC system Hx flow control valve, because locally brottlingof RBCCWwould take more time 5/13/96 Page 17

r PPO tttempted to establish steady l

cooldown r:te rather than stabilize temper:ture folknving '

i addition of 2nd heat exchanger.

1. 39 l 2/22 Visual trends of l V # 40 co Idown temperatures

! located on OPS B CRT on PPO used "SDC" display on CRTlo- Shift Manager's desk.

cated on CO4 for digital flow values. #37 Ucensed operator is

1. 36 considered qualified y . . for any control

1. 38 No guidance in #35 PPO had not room task.

pr c dure on m previously performed CO provided PPO only with adding second heat '

direction T351Y, SDC to RCS cooldown.

• ' ' "E

Temperature,was moving not magnitudes from Shift Manager's CRT.

+

Reduced flow through PPO had difficulty maintaining SI-657, SDC System T351Y stable after RBCCW flow to Hx flow control valve, heat exchanger initiated. until cooldown rate below 20*F/hr.

• 0700 L *0715 y L 0715 L 0755 L 0942 L Entered Exited 3.4.9.1.b. Exited 3.0.3. T351X, 3.4.9.1.b. Pressure Pressure Tempcrature Shift RCS to SDC Temperature,

> Temperature Umits, > Limits, cooldown rate 0.3. time y turnover. Y indicated < 200*E 4 ded cooldown rate -5'F/hr.

33*F/hr. .

Ak

• Actual violation of Requested Engineering cooldown rate occurred at Evaluation as required by Tech. Spec. 3.4.9.1.

0700. Incorrect placement of RCS AT/hr values on OPS Form 2602B-1 resulted in a 0715 log entry. Similar result for exiting 3.4.9.1.b.

5/13/96 Page 18 -

I

- Attachment # 8.4 -

Millstone Unit 2 - RCS Cooldown Event ,

February 22,1996 Technical Support review PORC Operator training 03rf1 CTS of bases for cooldown ,

I instrumentation T351X N

1. 1 #2 #3 W f rmal training was Information regarding T351X The following contributerk vs.T351Y was requested - disorganization pr nded on SP 2602B; er informally; Resulted in no - desire to approve procedures

'** Lim.ted i simulator l feedback from Structural & and Tech. Manual Clarification training on the Design Support. as soon as possible

-lead presenter selected at pedonnance of M cooldowns; meeting

- System Engineers did not No training using T351Y attend meeting Additional Info 5/13/96 Page1

. Attachment # 8.4 Millston Unit 2 - RCS Cooldown Event .

February 22,1996 Plant Process Computer Surveillance procedure Operating procedure SP 2602B OP 2310 BalTiers D N'

1. 4 #5 Q f6 EVENT RCS cooldown rate >30

• Fin any one hour Specially built trends were Although the frequency of Procedure was not Cause of revised to include pr vided on the Shift performance was increased Barrier to once every 15 minute, addition or swapping of Manager's CRT, Breakdown this still was not often heat exchangers or PPC no longer calculated enough to let the operator steps to ensure SI-657 cooldown rate; know about large was in a preferable cooldowns over a few operating band; minutes Additional Monitoring once every 15 Info minutes will not ensure heat up rate is not exceeded some time during hour 5/13/96 Page 2

Attachment # 8.5 Millstone Unit 2 - RCS Cooldown Event February 22,1996 Change Analysis Prior to the Event At the Time of the Event

- During SDC operation, T351X, - T351X, RCS to SDC temperature, RCS to SDC temperature, was used used for mode change; T351Y, SDC to for cooldown rate and mode change RCS temperature, was used to monitor cooldown rate; this combination was the most conservative

- The plant process computer - The heatup/cooldown program on the provided cooldown data and plant process computer was secured; displays available at all control specially constructed cooldown displays t room CRTs; computer provided were located on the Shift Manager's CRT cooldown rate values every minute Page1 5/13/96

Attachment # 8.5 .

Millstone Unit 2 - TSAS 3.03 Event February 22,1996 Change Analysis Prior to the Event At the Time of the Event

- T351X, RCS to SDC temperature, - T351Y, SDC to RCS temperature, was used to monitor cooldown rate was used to monitor cooldown rate and determine mode change; this during SDC system operation; this temperature indicator was quite temperature indicator was quite unstable stable during SDC system initiation during SDC system initiation and adding and adding or swapping heat or swapping heat exchangers due to its exchangers due to its location; location;

- There was no concern with - In order to ensure mixing in the ensuring mixing in the downcomer downcomer, SDC initiation was -

during SDC system initiation; 1000 Performed over approximately 30 gpm was usually achieved within a minutes before reaching 1000 gpm; few minutes; 5/13/96 Page 2

h 25 9 54-9 73-9 03 9 22:9 r p c Dt +

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Attachment 4 8.6 i (This figure included in Attachment to illustrate SDC system layout) i t

10:08:O* SHUTDOWN COOLING S"C P"9* 32-"av75 OY t

MASTER HOST B ~

T3s1X INLET TEMP 136.7 2-S1-ssi 2-Si-ss2 r ," 'xLOOP 2 HOT LEG P302X T303X DISCH PSIG DISCH TEMP LOOP 1A A SDC HX 2-S1_613 18,,t . c., ' s 131.1 F3023

FLOW GPM T l j O ,

TEMP bl4,4 Qg}

i I 131.4 F312 Fe w A 8

2-SI-657  :

LPSI PP ' - LOOP 1B i

P3051 R -33.5 7 m .

2-Si-s2s A J

^ '  :

25.1 E nBESTEtw 2986.6 648.6 F30s P302Y SDC TOTfV,- F322 FLOW DISCH PSIG FLOW GPM gg

'7-27.3 2-Sr-63s LOOP 2A F3024 u 2 g

FLOW GPM ,

i 542.0 134.g , F332 FtOW j LPSI PP R 209.4 T303v LOOP 2B

P3033 SUCT F6042 RBCCW FLOW hh" 7 w

25.8 PSIG GPM 2-SI-306 1319.1 F342 FLOW Meta;st sotD...

A 5/13/96 2 Millstone Unit 2 Cooldown Event

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Attachment 9 8.6

~

17-28-24 - -

UISURL TREND 1 ops 7ri 26-Fee-96 g as definea E.s CRT OPS 7 Page 1 of 1 300.000 -

! i pac 23 rf " " " " " ~ ~

260.000' ~~if f 5 Too33 l

~

F3c24

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~ 0. OOp'-

~ ~ ~ ~ ' ~ ~ ~ ~

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a  !

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l .. ._ . . ... . l 1 k1. .. ll _.! l 1. .

100.000 06:45:00 06:57:00 07:09:00 07:21:00 07:33:00 07:45:00 02/22/96 02/22/96 02/22/96 O2/22/96 02/22/96 02/22/96 0

• ho o~2. coo 0-2 coo T351Y DEGF F6043 GPM F6042 GPM F3023 GPM 104.85 R -350.20 2505.9 1602.0 F3024 GPI1 M3'1 DEGF  !

1536.0 71.969 72.500 i

FESS PE38.f t 1E FEa f OF f lOF.E DATH

~5/13/96 4 Millstone Unit 2' i Cooldown Event ,

i

9 Attachment # 8.6 TREND 18 31-3B UISURL 1 ogsny1 13_ne,_,6

,. a 1,ma s wr .- noe.

1 e. i MASTER HOST 5 210.000 200.000 T35'l Y

~'.-

190.000 i 180.000 ,

a  !

170.000 i 160.000 05:58:10 06:10:10 06:22:10 06:34:10 06:46:10 06:58:10 02/22/96 02/22/96 02/22/96 02/22/96 02/22/96 02/22/06 ,

T351Y DEGF ,

127.60 l

~' ~ '

NESS RESUME ~MEY FOR MORE DRTA 5/13/96 5 Millstone Unit 2 Cooldown Event

_ . - - _ - . . _ _ _ _ _ . _ _ _ _ . _ _ _ _ _ _ _ _ _.___.__A _ _ _ . __ _ _ _ _ _ _ _ . _ . - . _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ .

Attachment # 8.6 TREND

~

18 26.Og .

VISUAL s.., egr og.,n 1 OrsaT1 1,3_nge_

c. i ,6

. m 3,. 3 , ,- c. ,,,,

MASTER HOST 5 230.000

_-_ 735 X '

216.000 202. we 73,f J7 h, N_ _._. _ A ,

(l t88.000  %

W l l

\A 174.000

(

160.000 06:58:10 05:58:10 06:10:10 06:22:10 06:34:10 06:46:10 02/22/96 02/22/96 02/22/96 02<22/06 02/22/96 02/22/96 T351X DECE T351Y DEGF 134.40 127.60

• ' " ~

MESS ' PEBER1E' KEY' FOR MORE DATR 5/13/96 6 Millstone Unit 2 Cooldown Event

_ i

. l Attachment # 8.6  !

~ '

13 38-3(E VISURL TREND 1 ogSer1 12_or,_,6 m a . t r.<.a s. co r en e.g. 2 .,. i MASTER HOST 5 220.000 i m

209.000 x

• ~

yy

% l

~ '

%.,- _ t 184.000 'W j 6

172.000 l f

+

160.000 06:30:00 06:42:00 06:54:00 07:06:00 07:18:00 07:30:00 02/22/96 02/22/96 02/22/96 02/22/96 02/22/96 02/22eo6 <

T351X DEGF T351Y DEGF l 134.34 127.47

• i

~ '

SPESS RESUME WT.N FOR MORE DRTA

. t 5/13/96 7 Millstone Unit 2 Cooldown Event

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Attrchment O 8.7 Millstone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2Sl657# 2S1657= Y CootRate X CoolRate 5:51:40 226.875 200.275 3066.25 957.535 212.129 634.305 718.07 36.75 0.00E+00 0.00E+00 -17.435 -11.562 5:51:50 226.812 200.187 3003.18 966.307 212.129 631.219 707.106 36.75 0.00E+00 0.00E+00 -17.398 -11.583 5:52:00 226.812 200.087 3026.03 960.468 212.129 661.437 726.184 36.75 0.00E+00 0.00E+00 -17.186 -11.521 5:52:10 226.812 200.025 3039.92 963.392 212.129 670.237 731.543 36.75 0.00E+00 0.00E+00 -17.123 -11.563 5:52:20 226.687 199.775 3015.9 977.88 198.428 655.505 744.773 36.75 0.00E+00 0.00E+00 -17.81 -11.688 5:52:30 226.709 199.588 3020.97 960.468 212.129 652.519 739.509 36.75 0.00E+00 0.00E+00 -18.122 -11.561 5:52:40 226.709 199.562 3049.53 954.593 198.428 651.879 733.63 36.7079 0.00E+00 0.00E+00 -18.086 -11.603 5:52:50 226.687 199.463 3105.94 957.535 224.998 655.505 744.773 36.7392 0.00E+00 0.00E+00 -18.247 -11.625 5:53:00 226.625 199.4 3028.56 963.392 212.129 664.383 739.509 36.75 0.00E+00 0.00E+00 -18.498 -11.625 5:53:10 226.625 199.338 3063.75 969.213 212.129 661.437 726.184 36.75 0.00E+00 0.00E+00 -18.185 -11.625 5:53:20 226.562 199.213 3105.94 963.392 224.998 661.437 739.509 36.7187 0.00E+00 0.00E+00 -17.872 -11.625 5:53:30 226.5 199.15 3065 963.392 212.129 658.477 736.863 36.6875 0.00E+00 0.00E+00 -17.31 -11.687 5:53:40 226.5 199213 3034.88 957.535 198.428 661.437 742.146 36.6875 0.00E+00 0.00E+00 -16.498 -11.562 5:53:50 226.5 199.275 3056.24 960.468 198.428 661.437 739.509 36.6875 0.00E+00 0.00E+00 -16.061 -11.5 5:54:00 226.437 199.275 3063.75 969.213 212.129 660.805 736.287 36.6875 0.00E+00 0.00E+00 -16.123 -11.5 5:54:10 226.437 199.275 3073.73 954.593 212.129 664.383 720.785 36.6875 0.00E+00 0.00E+00 -16.186 -11.458 5:54:20 226.437 199275 3072.48 957.535 212.129 658.477 742.146 36.7187 0.00E+00 0.00E+00 -16.186 -11.438 5:54:30 226.375 199.213 3080.75 983.615 224.998 660.805 725.601 36.7079 0.00E+00 0.00E+00 -16.123 -11.5 5:54:40 226.375 199.213 3043.69 963.392 224.998 661.437 739.509 36.75 0.00E+00 0.00E+00 -16.185 -11.5 5:54:50 226.375 199.275 3071.24 969.213 198.428 655.505 739.509 36.75 0.00E+00 0.00E+00 -16.498 -11.5 5:55:00 226.272 199.213 3066.25 951.643 212.129 646.504 718.07 36.75 0.00E+00 0.00E+00 -16.498 -11.54 5:55:10 226.312 199.213 3074.97 960.468 212.129 658.477 728.868 36.7812 0.00E+00 0.00E+00 -16.685 -11.438 5:55:20 226.25 199.213 3066.25 966.307 224.998 664.383 728.868 36.7812 0.00E+00 0.00E+00 -17.06 -11.5 5:55:30 226.209 199.088 3104.71 957.535 212.129 657.844 736.863 36.7812 0.00E+00' O.00E+00 -17.247 -11.436 5:55:40 226.187 199.025 3009.54 951.643 212.129 658.477 715.345 36.8437 0.00E+00 0.00E+00 -16.873 -11.5 5:55:50 226.187 199.088 3028.56 957.535 212.129 655.505 739.509 36.8437 0.00E+00 0.00E+00 -16.373 -11.438 5:56:00 226.187 199.088 3042.43 960.468 212.129 649.518 742.146 36.8437 0.00E+00 0.00E+00 -16.06 -11.438 5:56:10 226.022 199.15 3080.75 951.643 212.129 648.877 741.573 36.8437 0.00E+00 0.00E+00 -15.498 -11.603 5:56:20 226.C22 199.15 3035.69 948.683 212.129 648.877 725.601 36.8641 0.00E+00 0.00E+00 -15.412 -11.603 5:56:30 226.062 199.15 3091.12 966.307 212.129 664.383 744.773 36.875 0.00E+00 0.00E+00 -15.686 -11.5 5:56:40 226 199.213 3042.43 960.468 212.129 646.504 744.773 36.875 0.00E+00 0.00E+00 -15.748 -11.562 5:56:50 226 199.088 3061.25 957.535 212.129 670.237 752.599 36.875 0.00E+00 0.00E+00 -15.935 -11.562 5:57:00 225.937 199.025 3120.7 972.111 224.998 670.237 757.772 36.8437 0.00E+00 0.00E+00 -15.936 -11.563 5:57:10 225.875 198.963 3039.92 957.535 212.129 681.794 731.543 36.8437 0.00E+00 0.00E+00 -15.998 -11.625 Millstone Unit 2. 2/22/96 5/10/96 Page 1 Cooldown Event Review

Attachment # 8.7 Mi!! stone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 (2S1657# 2S1657= Y CoolRate X CoolRate 5:57:20 225.875 198.713 3014.63 960.468 198.428 684.652 750 36.843710.00E+00 0.00E+00 -15.81 -11.625 5:57:30 225.812 198.713 3023.5 954.593 183.708 670 237 757.772 36.8125 0.00E+00 0.00E+00 -15.06 -11.688 5:57:40 225.709 198.65 3040.73 989.317 198.428 669.613 769.997 36.7704 0.00E+00 0.00E+00 -14.873 -11.728 5:57:50 225.709 198.588 3050.79 936.749 212.129 681.179 741.573 36.7704 0.00E+00 0.00E+00 -14.935 -11.666 5:58:00 225.647 198.525 3055.8 957.535 212.129 689.726 746.822 36.7704 0.00E+ 00 0.00E+00 -14.436 ' -11.665 5:58:10 225.687 198.4 3094.83 960.468 212.129 670.237 752.599 36.75 0.00E+00 0.00E+00 -13.998 -11.563 5:58:20 225.647 198.338 3048.28 969.213 212.129 684.039 764.907 36.7392 0.00E+00 0.00E+00 -13.748 -11.54 5:58:30 225.687 198.338 2996.79 951.643 212.129 687.499 752.599 36.7392 0.00E+00 0.00E+00 -14.123 -11.438 5:58:40 225.584 198.15 3044.51 972.111 212.129 686.888 738.935 36.7392 0.00E+00 0.00E+00 -14.623 -11.416 5:58:50 225.584 198.025 3038.66 977.88 224.998 684.652 744.773 36.7187 0.00E+00 0.00E+00 -15.186 -11.416 5:59.00 225.584 197.963 3043.25 963.392 212.129 689.726 749.432 36.6767 0.00E+00 0.00E+00 -15.435 -11.311 5:59:10 225.562 197.838 3023.5 963.392 212.129 698.771 750 36.7187 0.00E+00 0.00E+00 -15.685 -11.313 5:5920 225.625 197.775 3033.61 960.468 212.129 681.794 757.772 36.7187 0.00E+00 0.00E+00 -15.623 -11.25 5:59:30 225.625 197.775 3081.19 957.535 212.129 690.334 752.599 36.75 0.00E+00 0.00E+00 -15.248 -11.083 5:59:40 225.625 197.9 302224 951.643 212.129 690.334 760.345 36.75 0.00E+00 0.00E+00 -14.873 -11.062 5:59:50 225.562 197.963 3047.46 960.468 198.428 673.145 742.146 36.7812 0.00E+00 0.00E+ 00 -14.623 -11.125 6:00:00 225.584 198.025 3075.78 951.643 212.129 689.726 757.209 36.8016 0.00E+00 0.00E+00 -14.623 -10.999 6:00:10 225.522 198.025 3054.99 960.468 212.129 676.04 752.599 36.8016 0.00E+00 0.00E+00 -14.85 -10.998 6:00:20 225.522 198.088 3043.25 963.392 212.129 681.179 754.626 36.8329 0.00E+00 0.00E+00 -14.787 -10.998 6:00:30 225.562 198.025 3037.4 960.468 212.129 678.923 762.909 36.8125 0.00E+00 0.00E+00 -14.623 -10.938 6:00:40 225.5 198.025 3086.16 954.593 198.428 673.145 755.19 36.875 0.00E+00 0.00E+00 -14.35 -10.937 6:00:50 225.5 198.15 3038.66 960.468 212.129 681.794 760.345 36.8437 0.00E+00 0.00E+00 -14.373 -10.812 6:01:00 225.5 198.025 3032.35 930.725 212.129 673.145 773.081 36.8437 0.00E+00 0.00E+00 -14.811 -10.75 6:01:10 225.459 197.963 3023.06 936.749 212.129 672.523 759.784 36.7704 0.00E+00 0.00E+00 -15.123 -10.666 6:01:20 225.375 197.963 3033.61 966.307 212.129 704.339 750 36.7812 0.00E+00 0.00E+00 -14.935 -10.75 6:01:30 225.375 197.963 3051 23 939.747 212.129 687.499 770.551 36.75 0.00E+00 0.00E+00 -14.31 -10.75 6:01:40 225.375 197.963 3042.43 942.735 212.129 681.794 757.772 36.7187 0.00E+00 0.00E+00 -13.935 -10.625 '

6:01:50 225.312 197.963 3050.79 960.468 212.129 684.039 744.202 36.6875 0.00E+00 0.00E+00 -13.724 -10.688 6:02:00 225.312 197.963 3037.4 948.683 212.129 690.334 752.599 36.6562 0.00E+00 0.00E+00 -13.787 -10.646 6:02:10 225.312 197.963 3013.36 945.713 212.129 687.499 747.391 36.6562 0.00E+00 0.00E+00 -13.623 -10.5 6:02-20 225.147 197.838 3050.79 963.392 212.129 681.179 744.202 36.6454 0.00E+00 0.00E+00 -13.935 -10.499 6:02:30 225.147 197.838 3071 24 983.615 212.129 687.499 755.19 36.6875 0.00E+00 0.00E+00 -13.686 -10.54 6:02:40 225.062 197.838 3041.18 939.747 212.129 701.56 765.465 36.6767 0.00E+00 0.00E+00 -13.498 -10.563  !

6:02:50 224.959 197.775 3074.53 969.213 212.129 717.481 764.907 36.6767 0.00E+00 0.00E+00 -13.249 -10.562 Millstone Unit 2,2/22/96 5/10/96 Page 2 Cooldown Event Review

Attechment # 8.7 -

Millstone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2S1657# 2S1657= Y CootRate X CootRate 6:03:00 224.959 197.588 3103.48 972.111 224.998 698.169 793.035 36.7187 0.00E+00 0.00E+00 -13.373 -10.541 6:03:10 225 197.4 3102.24 951.643 212.129 707.106 757.772 36.7187 0.00E+00 0.00E+00 -13.936 -10.5 6:03:20 224.897 197.275 3037.4 969213 212.129 707.106 765.465 36.7187 0.00E+00 0.00E+00 -14.061 -10.603 6:03:30 224.897 197.088 3037.4 951.643 212.129 712.609 755.19 36.6875 0.00E+00 0.00E+00 -13.811 -10.478 6:03:40 224.875 197.088 3072.48 966.307 212.129 701.56 773.081 36.625 0.00E+00 0.00E+00 -14.061 -10.562 6:03:50 224.812 197.025 3049.97 972.111 198.428 712.609 765.465 36.5937 0.00E+00 0.00E+00 -14.624 -10.5 6:04:00 224.812 196.963 3008.27 951.643 212.129 728.868 770.551 36.5937 0.00E+00 0.00E+00 -14.623 -10.5 6:04:10 224.812 196.963 3094.83 945.713 212.129 698.771 757.772 36.5937 0.00E+00 0.00E+00 -14.498 -10.5 6:04:20 224.75 196.963 3128.05 966.307 212.129 709.863 757.772 36.5937 0.00E+00 0.00E+00 -14.498 -10.5 6:04:30 224.75 196.963 3071.24 939.747 198.428 712.609 760.345 36.5625 0.00E+00 0.00E+00 -14.686 -10.437 6:04:40 224.75 196.9 3097.3 954.593 212.129 715.345 773.081 36.5625 0.00E+00 0.00E+00 -14.873 -10.437 6:04:50 224.687 196.9 3082.44 948.683 212.129 709.863 778.118 36.5937 0.00E+00 0.00E+00 -15.123 -10.5 6:05:00 224.687 197.025 3034.88 960.468 224.998 712.609 760.345 36.625 0.00E+00 0.00E+00 -14.998 -10.438 6:05:10 224.522 197.025 3049.53 972.111 212.129 717.481 780.075 36.6142 0.00E+00 0.00E+00 -14.811 -10.603 6 05:20 224.562 197.025 3057.5 948.683 212.129 707.106 770.551 36.6562 0.00E+00 0.00E+00 -14.374 -10.5 6:05:30 224.562 197.088 3078.71 945.713 212.129 718.07 797.946 36.625 0.00E+00 0.00E+00 -13.936 -10.438 6:05:40 224.562 197.025 3037.4 951.643 212.129 734.208 797.946 36.6562 0.00E+00 0.00E+ 00 -13.811 -10.375 6:05:50 224.5 196.963 3081.19 963.392 212.129 736.863 790.569 36.6562 0.00E+00 0.00E+00 -13.686 -10.312 6:06:00 224.459 196.775 3151.99 966.307 212.129 722.905 811.969 36.6562 0.00E+00 0.00E+00 -13.686 -10.416 6:06:10 224.437 196.525 3071.24 960.468 212.129 757.772 802.827 36.625 0.00E+00 0.00E+00 -13.999 -10.313 6:06:20 224.5 196.463 3102.24 951.643 198.428 747.391 790.569 36.6562 0.00E+00 0.00E+00 -14.311 -10.187 6:06:30 224.437 196.15 3062.06 963.392 212.129 764.907 799.852 36.6454 0.00E+00 0.00E+00 -14.686 -10.188 6:06:40 224.437 195.838 3088.64 963.392 212.129 747.391 792.494 36.625 0.00E+00 0.00E+00 -15.186 -10.125 6:06:50 224.334 195.776 3031.09 939.747 224.998 755.19 807.144 36.5829 0.00E+00 0.00E+00 -14.998 -10.124 6:07:00 224.334 195.588 3092.35 954.593 212.129 744.773 790.569 36.5829 0.00E4 00 0.00E+00 -14.686 -10.103 6:07:10 224.272 195.651 3102.24 963.392 212.129 742.146 800.39 36.5517 0.00E+00 0.00E+00 -14.685 -10.103 6:07:20 224.312 195.651 3039.92 969213 212.129 742.146 790.569 36.5625 0.00E+00 0.00E+00 -14.998 -10 6:07:30 224.312 195.776 3088.64 936.749 212.129 744.773 800.39 36.5625 0.00E+00 0.00E+00 -15.06 -9.938 6:07:40 224.25 195.838 3069.99 951.643 212.129 747.391 788.095 36.5312 0.00E+00 0.00E+00 -15.061 -9.937 6:07:50 224.187 195.812 3060 960.468 212.129 750 802.827 36.5625 0.00E+00 0.00E+00 -14.774 -10 6:08:00 224.125 195.812 3046.21 969.213 212.129 744.773 819.679 36.5625 0.00E+00 0.00E+00 -14.962 -10.062 6:08:10 224.125 195.838 3068.74 948.683 198.428 755.19 805.256 36.625 0.00E+00 0.00E+00 -15.061 -10 6:08:20 224.062 195.776 3054.99 954.593 212.129 752.599 810.092 36.5937 0.00E+00 0.00E+00 -14.935 -10.063 6:08:30 224 195.838 2986.56 957.535 212.129 752.599 788.095 36.625 0.00E+00 0.00E+00 -14.998 -10.125 Millstone Unit 2,2/22/96 5/10/96 Page 3 Cooldown Event Review

Attcchment # 8.7 Millstone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2Sl657# 2S1657= Y CooIRate X CootRa'e 6:08:40 223.96 195.776 3060 948.683 212.129 750 833.853 36.6875 0.00E+00 0.00E+00 -14.935 -10.061 6:08:50 224 195.713 3078.71 951.643 198.428 783.122 814.9 36.6875 ' O.00E+00 0.00E+00 -14.998 -10.021 6:09:00 223.897 195.526 3107.97 945.713 224.998 775.052 847.277 36.6875 0.00E+00 0.00E+00 -15.185 -10.165 6:09:10 223.835 195.463 3128.83 951.643 212.129 772.528 847.277 36.7079 0.00E+00 0.00E+00 -15.061 -10.165 6:09:20 223.875 195.338 3068.74 972.111 198.428 797.946 822.059 36.7187 0.00E+00 0.00E+00 -15.061 -10.125 6:09:30 223.875 195.338 3104.71 945.713 212.129 778.118 833.853 36.7187 0.00E+00 0.00E+00 -14.811 -10.062 6:09:40 223.835 195.151 3062.06 948.683 198.428 777.568 828.633 36.7079 0.00E+00 0.00E+00 -14.498 -10.04 6:09:50 223.812 195.151 3082.44 960.468 224.998 765.465 836.192 36.7187 0.00E+00 0.00E+00 -14.31 -9.959 6:10:00 223.812 195.151 3067.5 969.213 198.428 770.551 836.192 36.7187 0.00E+00 0.00E+00 -14.435 -10 6:10:10 223.75 195.213 3096.07 966.307 212.129 780.624 819.679 36.75 0.00E+00 0.00E+00 -14.498 -10.062 6:10:20 223.71 195.213 3052.04 951.643 224.998 769.997 821.532 36.7079 0.00E+00 0.00E+00 -14.743 -10.04 6:10:30 223.71 195.213 3101.01 945.713 198.428 773.081 838.525 36.75 0.00E+00 0.00E+00 -15.037 -9.936 6:10:40 223.687 195.213 3091.12 977.88 198.428 783.122 843.171 36.7187 0.00E+00 0.00E+00 -15.123 -9.959 6:10:50 223.585 195.25 3086.16 966.307 212.129 780.624 829.156 36.7079 0.00E+00 0.00E+00 -15.149 -10.04 6:11:00 223.562 195.338 3076.22 948.683 212.129 780.624 819.679 36.7187 0.00E+00 0.00E+00 -15.186 -10 6:11:10 223.562 195.338 3095.63 951.643 198.428 790.026 833.333 36.7187 0.00E+00 0.00E+00 -14.873 -9.938 6:11:20 223.5 195.338 3083.68 954.593 212.129 800.39 838.525 36.7187 0.00E+00 0.00E+00 -14.686 -10 6:11:30 223.5 195.276 3108.41 954.593 212.129 817.293 863.767 36.7187 0.00E+00 0.00E+00 -14.873 -9.958 6:11:40 223.437 195.026 3151.21 954.593 212.129 826.797 836.192 36.75 0.00E+00 0.00E+00 -14.873 -10 6:11:50 223.437 194.713 3120.7 960.468 212.129 807.678 859.232 36.75 0.00E+00 0.00E+00 -14.811 -10 6:12:00 223.437 194.463 3113.33 939.747 212.129 814.9 856.956 36.75 0.00E+00 0.00E+00 -15.186 -9.938 6:12:10 223.437 194.338 3109.64 942.735 212.129 805.256 861.503 36.75 0.00E+00 0.00E+00 -15.498 -9.896 6:12:20 223.375 194.338 3126.82 954.593 212.129 814.9 874.999 36.7187 0.00E+00 0.00E+00 -15.623 -9.937 6:12:30 223.335 194.401 3128.83 963.392 212.129 830.987 858.724 36.7187 0.00E+00 0.00E+00 -15.248 -9.915 6:12:40 223.375 194.401 3130.49 948.683 198.428 819.679 861.503 36.75 0.00E+00 0.00E+00 -15.185 -9.937 6:12:50 223.312 194.276 3078.71 936.749 198.428 840.851 856.956 36.7187 0.00E+00 0.00E+00 -15.185 -9.938 6:13:00 223.25 194.213 3099.77 960.468 212.129 833.853 843.171 36.6875 0.00E+00 0.00E+00 -15.248 -10 6:13:10 223.25 194.088 3110.87 948.683 212.129 843.171 856.956 36.6562 0.00E+00 0.00E+ 00 -15.248 -9.937.

6:13:20 223.187 194.026 3i42.7 954.593 198.428 829.156 861.503 36.6562 0.00E+00 0.00E+00 -15.31 -10.063 6:13:30 223.125 193.963 3110.87 948.683 198.428 810.092 868.277 36.6562 0.00E+00 0.00E+00 -15.123 -10.062 6:13:40 223.125 193.963 3104.71 957.535 212.129 836.192 879.452 36.6562 0.00E+00 0.00E+00 -14.998 -10 6:13:50 223.062 194.026 3150 966.307 224.998 817.293 877.229 36.6562 0.00E+ 00 0.00E+00 -14.935 -10.063 6:14:00 223 194.125 3125.6 957.535 212.129 829.156 863.767 36.6562 0.00E+00 0.00E+00 -14.961 -10.125 6:14:10 222.897 194.276 3114.12 948.683 212.129 821.532 860.996 36.6767 0.00E+00 0.00E+00 -14.935 -10.165 Millstone Unit 2,2/22/96 5/10/96 Page 4 Cooldown Event Review

Attachment O 8.7 Mil! stone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2St657# 2S1657= Y Coo Rate X CoolRate 6:14:20 222.937 194.338 3139.04 960.468 212.129 826.797 850.092 36.6875 0.00E+00 0.00E+00 -14.748 -10.084 6:14:30 222.875 194.276 3148.34 942.735 198.428 826 273 851.875 36.6875 0.00E+00 0.00E+00 -14.123 -10.146 6:14:40 222.812 194.213 3123.15 939.747 198.428 819.679 868.277 36.6562 0.00E+00 0.00E+00 -13.936 -10.188 6:14:50 222.75 194.213 3096.07 948.683 212.129 824.431 863.767 36.6562 0.00E+00 0.00E+00 -14.311 -10.25 6:15:00 222.687 194.213 3060.81 948.683 212.129 833.333 867.773 36.6562 0.00E+00 0.00E+00 -14.787 -10.313 6:15:10 222.585 194.026 3129.27 951.643 212.129 810.092 877.229 36.625 0.00E+00 0.00E+00 -15.31 -10.352 6:15:20 222.562 193.963 3119.47 945.713 212.129 824.431 872.764 36.6562 0.00E+00 0.00E+00 -15.748 -10.375 6:15:30 222.46 193.963 3103.04 924.662 212.129 821.532 874.499 36.6454 0.00E+00 0.00E+00 -15.998 -10.477 6:15:40 222.397 194.026 3041.18 960.468 224.998 845.484 850.092 36.6454 0.00E+00 0.00E+00 -15.935 -10.478 6:15:50 222.335 193.963 3078.27 960.468 212.129 826.273 865.52 36.6454 0.00E+00 0.00E+00 -15.748 -10.54 6:16:00 222.375 193.776 3134.16 966.307 212.129 814.37 852.386 36.6875 0.00E+00 0.00E+00 -15.873 -10.5 6:16:10 222.312 193.776 3139.82 951.643 198.428 830.987 883.386 36.6875 0.00E+00 0.00E+00 -15.748 -10.438 6:16:20 222.25 193.776' 3173.77 966.307 212.129 854.164 900.898 36.7187 0.00E+00 0.00E+00 -15.81 -10.437 6:16:30 222.25 193.463 3162.13 933.742 212.129 863.767 888.292 36.75 0.00E+00 0.00E+00 -16.186 -10.375 6:16:40 222.187 193.151 3162.13 951.642 198.428 870.524 892.678 36.7812 0.00E+00 0.00E+00 -16.498 -10.375 6:16:50 222.187 192.937 3078.71 951.643 198.428 879.452 863.767 36.8125 0.00E+00 0.00E+00 -16.649 -10.375 6:17:00 222.125 192.713 3077.02 954.593 198.428 870.021 894.371 36.8125 0.00E+00 0.00E+00 -16.498 -10.375 6:17:10 222.062 192.526 3173.01 921.615 198.428 881.67 897.043 36.8125 0.00E+00 0.00E+00 -16.748 -10.375 6:17:20 222 192.526 3128.05 945.713 212.129 892.678 912.157 36.8437 0.00E+00 0.00E+00 -16.685 -10.437 6:17:30 222 192.338 3212.13 966.307 212.129 898.728 924.435 36.8437 0.00E+00 0.00E+00 -16.873 -10.312 6:17:40 221.937 192.276 3145.14 951.643 212.129 886.09 918.558 36.8125 0.00E+00 0.00E+00 -16.935 -10.375 6:17:50 221.937 g2.276 3134.94 942.735 212.129 894.371 909.527 36.8641 0.00E+00 0.00E+00 -16.81 -10.313 6:18:00 221.835 192.276 3171.8 954.593 212.129 890.487 897.043 36.8437 0.00E+00 0.00E+00 -16.56 -10.415 6:18:10 221.812 192.276 3159.71 951.643 212.129 892.678 894.863 36.8437 0.00E+00 0.00E+00 -16.623 -10.438 6:18:20 221.75 192.276 3099.77 933.742 212.129 899.218 907.864 36.8437 0.00E+00 0.00E+00 -16.81 -10.5 6:18:30 221.75 192.25 3174.21 945.713 224.998 901.387 874.999 36.875 0.00E+00 0.00E+00 -16.711 -10.437 6:18:40 221.687 192.276 3028.56 951.643 212.129 886.09 910.013 36.8437 0.00E+00 0.00E+00 -16.248 -10.438 6:18:50 221.687 192.276 3198.24 954.593 224.998 912.157 933.323 36.8437 0.00E+00 0.00E+00 -15.81 -10.438 6:19:00 221.625 192.25 3147.57 963.392 212.129 931.228 929.129 36.8125 0.00E+00 0.00E+00 -16.024 -10.5 6:19:10 221.522 192.026 3155.63 942.735 212.129 932.847 889.993 36.7704 0.00E+00 0.00E+00 -16.435 -10.54 6:19:20 221.5 191.839 3151.21 945.713 224.998 931.228 903.552 36.7704 0.00E+00 0.00E+00 -16.622 -10.625 6:19:30 221.5 191.589 3115.79 951.643 212.129 912.157 929.129 36.7812 0.00E+00 0.00E+00 -16.997 -10.687 6:19:40 221.5 191.526 3143.92 933.742 212.129 933.323 912.157 36.7812 0.00E+00 0.00E+00 -17.248 -10.687 6:19:50 221.397 191.651 3132.94 933.742 212.129 910.013 918.558 36.7704 0.00E+00 0.00E+00 -17.123 -10.728 Millstone Unit 2,2/22/96 5/10/96 Page 5 Cooldown Event Review

Attcchment C 8.7 Millstone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2S1657# 2S1657= Y CoolRate X CoolRate 6:20:00 221.375 191.651 3183.85 954.593 212.129 918.558 924.915 36.7812 0.00E+00 0.00E+00 -16.998 -10.708 6:20:10 221.375 191.714 3211.38 951.643 212.129 931.228 899.218 36.7812 0.00E+00 0.00E+00 -16.997 -10.75 6:20:20 221.25 191.839 3195.85 954.593 212.129 927.024 922.801 36.75 0.00E+00 0.00E400 -16.685 -10.875 6:20:30 221.25 191.901 3185.05 930.725 198.428 916.429 954.021 36.75 0.00E+00 0.00E+00 -16.123 -10.875 6:20:40 221.187 191.901 3181 936.749 212.129 918.076 915.946 36.75 0.00E+00 0.00E+00 -16.061 -10.834 6:20:50 221.085 191.963 3158.5 963.392 212.129 943.729 937.5 36.7392 0.00E+00 0.00E+00 -15.912 -10.977 l 6:21:00 221 191.776 3186.25 945.713 198.428 937.5 939.581 36.75 0.00E+00 0.00E+00 -15.873 -11 6:21:10 220.937 191.625 3241.05 936.749 212.129 941.657 937.5 36.75 0.00E+00 0.00E+00 -15.837 -11.021 6:21:20 220.875 191.401 3233.95 954.593 224.998 954.021 943.729 36.75 0.00E+00 0.00E+00 -16.186 -11.062 6:21:30 220.75 191.276 3160.48 930.725 183.708 973.817 953.552 36.75 0.00E+00 0.00E+00 -16.373 -11.146 6:21:40 220.75 191.026 3159.71 939.747 198.428 951.971 935.414 36.75 0.00E+ 00 0.00E+00 -16.561 -11.187 6:21:50 220.585 190.776 3179.8 954.593 212.129 959.676 941.184 36.7079 0.00E+00 0.00E+00 -16.811 -11.35_2 l 6:22:00 220.625 190.651 3163.34 942.735 212.129 970.26 924.915 36.7079 0.00E+00 0.00E+00 -16.936 -11.25 6:22:10 220.562 190.714 3132.94 942.735 212.129 954.021 945.796 36.6875 0.00E+00 0.00E+00 -16.748 -11.313 6:22:20 220.46 190.714 3203.03 942.735 198.428 964.203 933.323 36.6562 0.00E+00 0.00E+00 -16.748 -11.415 6:22:30 220.437 190.714 3230.4 954.593 212.129 960.143 933.323 36.625 0.00E+00 0.00E+00 -16.748 -11,313 6:22:40 220.375 190.776 3179.03 918.558 183.708 972.271 939.581 36.625 0.00E+00 0.00E+00 -16.599 -11.375 6:22:50 220.437 190.812 3197.04 927.698 212.129 976.281 945.796 36.6562 0.00c_+00 0.00E+00 -16.087 -11.313 6:23:00 220.375 190.714 3194.21 957.535 198.428 961.709 959.676 36.6875 0.00E+00 0.00E+00 -16.123 -11.312 6:23:10 220.25 190.714 3198.24 957.535 212.129 962.175 927.024 36.6562 0.00E+00 0.00E+00 -16.373 -11.375 6:23:20 220.187 190.776 3213.33 951.643 212.129 977.819 957.639 36.6562 0.00E+00 0.00E+00 -16.498 -11.397 6:23:30 220.062 190.714 3183.85 960.468 212.129 966.226 956.066 36.6562 0.00E+00 0.00E+00 -16.56 -11.5 6:23:40 220.062 190.714 3245.77 942.735 212.129 972.271 960.143 36.6875 0.00E+00 0.00E+00 -16.31 -11.5 6:23:50 220 190.589 3228.03 945.713 212.129 978.279 956.066 36.6875 0.00E+00 0.00E+ 00 -16.373 -11.459 6:24:00 219.937 190.464 3211.38 977.88 212.129 986.233 964.203 36.6875 0.00E+00 0.00E+00 -16.685 -11.563 6:24:10 219.835 190.339 3178.59 945.713 212.129 973.817 963.738 36.7079 0.00E+00 0.00E+00 -16.56 -11.602 6:24:20 219.875 190.276 3176.62 936.749 198.428 986.233 964.203 36.7187 0.00E+00 0.00E+00 -16.436 -11.5 6:24:30 219.75 190.151 3182.64 954.593 212.129 960.143 978.279 36.7187 0.00E+00 0.00E+00 -16.436 -11.625 6:24:40 219.75 190.151 3209 954.593 212.129 982.264 970.26 36.7187 0.00E+00 0.00E+00 -16.248 -11.562 6:24:50 219.687 190.214 3211.38 939.747 212.129 968.245 976.281 36.7187 0.00E+ 00 0.00E+00 -15.873 -11.584 6:25:00 219.562 190.214 3160.92 951.643 212.129 980.274 966.226 36.7187 0.00E+00 0.00E+00 -15.748 -11.647 6:25:10 219.562 190.214 3212.57 954.593 212.129 980.274 980.274 36.75 0.00E+00 0.00E+00 -16.06 -11.688 6:25:20 219.46 190.151 3151.99 942.735 212.129 983.792 959.676 36.75 0.00E+00 0.00E+00 -16.623 -11.727 6:25:30 219.46 190.151 3232.33 945.713 212.129 991.701 963.738 36.75 0.00E+00 0.00E+00 -17.061 -11.727 Millstone Unit 2,2/22/96 5/10/96 Page 6 Cooldown Event Review

Attachment # 8.7 .

Millstone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2SI657# 2Sf657= Y CootRate X CoolRate 6:25:40 219.437 190.214 3187.45 945.713 212.129 992.156 964.203 36.75 0.00E+00 0.00E+00 -17.248 -11.75 6:25:50 219.312 190.151 3156.07 951.643 212.129 982.264 974.278 36.75 0.00E+00 0.00E+00 -17.311 -11.875 6:26:00 219.312 190.026 3213.76 936.749 212.129 984.251 978.279 36.75 0.00E+00 0.00E+00 -17.436 -11.813 6:26:10 219.25 189.964 3195.85 951.642 198.428 994.123 990.186 36.75 0.00E+00 0.00E+00 -17.56 -11.812 6:26:20 219.25 189.901 3204.22 945.713 212.129 998.044 996.086 36.7187 0.00E+00 0.00E+00 -17.561 -11.812 6:26:30 219.187 189.714 3141.48 948.683 212.129 978.279 1021.26 36.6875 0.00E+00 0.00E+00 -17.56 -11.772 6:26:40 219.085 189.714 3158.06 930.725 212.129 1016.98 991.701 36.6767 0.00E+00 0.00E+00 -17.248 -11.852 6:26:50 219.062 189.812 3244.59 945.713 212.129 1003.9 986.233 36.6767 0.00E+00 0.00E+00 -17.025 -11.875 6:27:00 219 189.714 3228.03 930.725 212.129 990.186 998.044 36.6767 0.00E+00 0.00E+00 -17.31 -11.937 6:27:10 218.937 189.526 3245.77 936.749 198.428 992.156 996.086 36.6875 0.00E+00 0.00E+00 -17.623 -12 6:27:20 218.937 189.526 3151.99 942.735 212.129 1011.2 1003.45 36.6875 0.00E+00 0.00E+00 -17.536 -12 6:27:30 218.835 189.401 3188.21 948.683 183.708 1013.13 1005.39 36.6767 0.00E+00 0.00E+00 -17.561 -11.977 6:27:40 218.812 189.214 3231.14 948.683 198.428 1011.2 993.668 36.6454 0.00E+00 0.00E+00 -17.873 -12 6:27:50 218.71 189.089 3202.59 927.698 198.428 1018.9 1007.33 36.6454 0.00E+00 0.00E+00 -17.998 -12.04 6:28:00 218.71 189 . 3232.77 951.643 212.129 1017.43 1011.65 36.625 0.00E+00 0.00E+00 -18.087 -12.04 6:28:10 218.687 189 3229.21 936.749 212.129 1005.84 1025.08 36.625 0.00E+00 0.00E+00 -18.149 -12.063 6:28:20 218.585 188.839 3225.22 945.713 224.998 1015.06 997.591 36.5829 0.00E+00 0.00E+00 : -18.123 -12.102 6:28:30 218.625 188.% 4 3155.63 945.713 198.428 1001.5 995.631 36.6142 0.00E+00 0.00E+00 -17.623 -12.062 6:28:40 218.523 188.964 3197.04 957.535 212.129 1013.13 1013.58 36.625 0.00E+00 0.00E+00 -17.498 -12.102 6:28:50 218.562 189.026 3224.47 945.713 224.998 1007.78 1023.17 36.625 0.00E+00 0.00E+00 -17.123 -11.959 6:29:00 218.46 189.089 3239.86 942.735 212.129 1049.55 994.123 36.6562 0.00E+00 0.00E+00 -16.998 -12.061 6:29:10 218.437 189.089 3183.85 951.643 212.129 1026.98 1001.95 36.6562 0.00E+00 0.00E+00 -16.998 -12.063 6:29:20 218.398 188.964 3260.62 963.392 212.129 1030.33 1001.5 36.6454 0.00E+00 0.00E+00 -17.373 -12.102 6:29:30 218.375 188.901 3181.44 918.558 212.129 1011.65 1005.84 36.6562 0.00E+00 0.00E+00 -17.373 -12.084 6:29:40 218.375 188.776 3238.68 954.593 198.428 1013.58 1017.43 36.6875 0.00E+00 0.00E+00 -17.248 -12.125 6:29:50 218.375 188.651 3170.59 957.535 224.998 1009.72 1011.65 36.6875 0.00E+00 0.OnDoo -17.123 -12.125 6:30:00 218.25 188.651 3266.93 945.713 198.428 1034.56 992.156 36.7187 0.00E+00 _0.00E+00 -17.436 -12.25 6:30:10 218.25 188.651 3158.5 936.749 198.428 1013.58 1001.95 36.75 0.00E+00 0.00E+00 -17.748 -12.187 6:30:20 218.148 188.651 3229.96 933.742 212.129 1022.72 1013.13 36.7392 0.00E+00 0.00E+00 -17.936 -1T 1 9 6:30:30 218.125 188.651 3186.25 942.735 198.428 1019.34 974 278 36.7704 0.00E+00 0.00E+00 -18.061 -12.s12 6:30:40 218.023 188.714 3220.46 948.683 198.428 1001.5 965.762 36.8016 0.00E+00 0.00E+00 -17.873 -12.414 6:30:50 218.062 188.589 3236.32 942.735 198.428 1019.34 998.044 36.8016 0.00E+00 0.00E+00 -17.56 -12.313 6:31:00 218 188.589 3231.14 936.749 212.129 1034.12 983.792 36.8016 0.00E+00 0.00E+00 -17.623 -12.375 6:31:10 218 188.526 3129.27 948.683 212.129 1025.08 990.186 36.8329 0.00E+00 0.00E+00 -17.373 -12.375 Millstone Unit 2,2/22/96 5/10/96 Page 7 Cooldown Event Review

AttCchment # 8.7 .

Millstone Unit 2 February 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2S!657# 2S!657= Y CootRate X CoodRate 6:31:20 218 188.401 3206.61 951.643 212.129 1013.58 984.251 36.8125 0.00E+00 0.00E+00 -17.186 -12.375 6:31:30 217.937 188.437 3209 936.749 212.129 1011.65 1000 36.8437 0.00E+00 0.00E+00 -17.15 -12.438 6:31:40 217.875 188.375 3239.43 918.558 212.129 1020.81 995.631 36.8641 0.00E+00 0.00E+00 -17.274 -12.437 6:31:50 217.875 188.339 3220.9 942.735 212.129 1026.98 1001.95 36.8437 0.00E+00 0.00E+00 -17.498 -12.375 6:32:00 217.875 188.339 3271.61 939.747 212.129 1030.33 1036.44 36.8125 0.00E+00 0.00E+00 -17.373 -12.375 6:32:10 217.75 188.214 3270.44 927.698 212.129 1053.27 1030.78 36.8125 0.00E+00 0.00E+00 -17.123 -12.459 6:32:20 217.648 188.214 3270 942.735 198.428 1056.53 1005.39 36.8016 0.00E+00 0.00E+ 00 -17.06 -12.602 6:32:30 217.687 188.151 3237.5 927.698 212.129 1045.82 1011.65 36.7704 0.00E+00 0.00E+00 -17.061 -12.459 6:32:40 217.625 187.964 3223.28 951.643 212.129 1055.12 1007.78 36.7812 0.00E+00 0.00E+00 -17.373 -12.5 6:32:50 217.625 187.839 3264.58 954.593 212.129 1036.44 1036.44 36.7812 0.00E+00 0.00E+00 -17.56 -12.437 6:33:00 217.562 187.777 3251.22 939.747 198.428 1060.23 1022.72 36.7812 0.00E+ 00 0.00E+00 -17.622 -12.5 6:33:10 217.5 187.777 3239.86 945.713 212.129 1053.27 1019.34 36.7704 0.00E+00 0.00E+00 -17.81 -12.521 6:33:20 217.5 187.777 3271.61 945.713 212.129 1009.72 1040.21 36.7812 0.00E+00 0.00E+00 -17.997 -12.459 6:33:30 217.437 187.777 3228.03 933.742 198.428 1051.41 1021.26 36.7812 0.00E+00 0.00E+00 -18.247 -12.522 6:33:40 217.375 187.964 3262.24 942.735 198.428 1040.21 1003.9 36.7812 0.00E+00 0.00E+00 -18.185 -12.562 6:33:50 217.375 187.964 3283.29 924.662 198.428 1032.67 1030.78 36.75 0.00E+00 0.00E+00 -17.935 -12.5 6:34:00 217.312 188.026 3252.83 951.642 198.428 1051.41 1026.98 36.75 0.00E+00 0.00E+00 -17.623 -12.563 6:34:10 217.25 188.089 3206.61 939.747 198.428 1045.82 1013.58 36.7187 0.00E+00 0.00E+00 -17.123 -12.562 6:34:20 217.25 188.089 3247.69 951.643 212.129 1039.77 1007.78 36.7187 0.00E+00 0.00E+00 -17.248 -12.ti25 6:34:30 217.25 187.964 3198.24 930.725 212.129 1028.88 1015.5 36.6767 0.00E+00 0.00E+00 -17.473 -12.562 6:34:40 217.187 187.839 3215.71 948.683 212.129 1045.39 1026.54 36.6767 0.00E+00 0.00E+00 -17.685 -12.625 6:34:50 217.125 187.714 3226.84 942.735 212.129 1064.34 1034.56 36.6562 0.00E+00 0.00E+00 -17.685 -12.687 6:35:00 217.125 187.777 3265.75 930.725 183.708 1075.29 1055.12 36.6142 0.00E+00 0.00E+00 -17.497 -12.646 6:35:10 217.023 187.589 3288.68 927.698 198.428 1100 1043.52 3G.625 0.00E+00 0.00E+00 -17.56 -12.686 6:35:20 217.023 187.339 3226.64 942.735 212.129 1093.3 1042.08 36.625 0.00E+ 00 0.00E+00 -17.685 -12.664 6:35:30 217 187.089 3275.12 954.593 224.998 1082.53 1064.34 36.625 0.00E+00 0.00E+00 -17.81 -12.709 6:35:40 216.96 186.777 3203.78 942.735 212.129 1078.49 1050.98 36.6142 0.00E+00 0.00E+00 -18.122 -12.79 6:35:50 216.937 186.777 3266.93 948.683 224.998 1086.13 1047.69 36.625 0.00E+00 0.00E+00 -18.122 -12.75 6:36:00 216.875 186.839 3254.01 945.713 212.129 1064.34 1038.33 36.6562 0.00E+00 0.00E+00 -17.998 -12.709 6:36:10 216.812 186.902 3237.5 948.683 212.129 1058.82 1071.65 36.6454 0.00E+00 0.00E+ 00 -17.81 -12.709 6:36:20 216.75 187.062 3256.36 954.593 224.998 1093.3 1021.26 36.6454 0.00E+00 0.00E+00 -17.65 -12.771 6:36:30 216.75 187.277 3231.58 948.683 212.129 1077.1 1056.97 36.625 0.00E+00 0.00E+00 -17.56 -12.771 6:36:40 216.687 187.214 3179.03 945.713 212.129 1091.52 1047.69 36.6142 0.00E+00 0.00E+00 -17.685 -12.813 6:36:50 216.625 187.027 3248.12 954.593 212.129 1089.72 1047.69 36.625 0.00E+00 0.00E+00 -17.622 -12.875 Millstone Unit 2,2/22/96 5/10/96 Page 8 Cooldown Event Review

Attrchment O 8.7 ,

Millstone Unit 2 February 22,1996, PFC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2S1657# 2S1657= Y CooRate X CooiRate 6:37:00 216.523 186.964 3321.54 972.111 212.129 1125 1062.5 36.5829 0.00E+00 0.00E+00 -17.873 -12.977 6:37:10 216.523 186.839 3312.31 942.735 212.129 1119.78 1047.69 36.5937 0.00E+00 0.00E+00 -18.123 -12.852 6:37:20 216.5 186.527 3294.93 939.747 212.129 1111.02 1089.72 36.5937 0.00E+00 0.00E+00 -18.435 -12.875 6:37:30 216.5 186.402 3245.77 951.643 212.129 1109.26 1089.72 36.625 0.00E+00 0.00E+00 -18.685 -12.812 6:37:40 216.5 186.402 3256.36 951.643 224.998 1109.26 1080.73 36.625 0.00E+00 0.00E+00 -18.747 -12.875 6:37:50 216.5 186.464 3209 936.749 212.129 1130.2 1102.2 36.625 0.00E+00 0.00E+00 -18.623 -12.834 6:38-00 216.375 186.464 3235.13 936.749 212.129 1116.29 1080.73 36.625 0.00E+00 0.00E+00 -18.56 -12.896 6:38:10 216.375 186.339 3259.89 927.698 212.129 1119.78 1086.13 36.625 0.00E+00 0.00E+00 -18.435 -12.937 6:38:20 216.312 186.339 3228.03 939.747 198.428 1128.47 1105.74 36.625 0.00E+00 0.00E+ 00 -18.373 -13 6:38:30 216.21 186.277 3255.19 963.392 212.129 1145.64 1064.34 36.5937 0.00E+00 0.00E+00 -18.372 -13.04 6:38:40 216.21 186.339 326927 930.725 212.129 1138.8 1096.87 36.5937 0.00E+00 0.00E+00 -18.31 -13.102 6:38:50 216.125 186.214 3303.05 942.735 212.129 1138.8 1102.2 36.625 0.00E+00 0.00E+00 -18.498 -13.125 6:39:00 216.125 186.089 3268.1 945.713 212.129 1164.25 1096.87 36.625 0.00E+00 0.00E+00 -18.435 -13.062 6:39:10 216.125 186.027 3296.09 951.643 198.428 1162.57 1068 36.6562 0.00E+00 0.00E+00 -18.497 -13 6:39:20 216.062 185.902 3257.54 924.662 212.129 1159.2 1095.09 36.6875 0.00E+00 0.00E+00 -18.497 -13.063 6:39:33 216.062 185.902 3264.58 942.735 212.129 1150.75 1105.74 36.6875 0.00E+00 0.00E+00 -18.435 -13 6:39:40 216 185.777 3326.15 942.735 198.428 1147.35 1133.65 36.6875 0.00E+00 0.00E+00 -18.598 -13.021 6:39:50 215.937 185.777 3335.35 960.468 198.428 1184.21 1131.92 36.7187 0.00E+00 0.00E+00 -18.372 -13.022 6:40:00 215.937 185.714 3268.1 954.593 212.129 1165.92 1138.8 36.75 0.00E+00 0.00E+00 -18.435 -13.063 6:40:10 215.875 185.777 3293.77 936.749 212.129 1189.14 1130.2 36.75 0.00E+00 0.00E4 00 -18.122 -13.062 6:40:20 215.812 185.839 3302.61 924.662 212.129 1185.45 1175.52 36.7392 0.00E+00 0.00E+00 -18.123 -13.125 6:40:30 215.812 185.839 3326.15 942.735 212.129 1192.42 1150.75 36.7392 0.00E+00 0.00E+00 -18.123 -13.125 6:40:40 215.75 185.777 3337.64 972.111 212.129 1184.21 1200.59 36.7392 0.00E+00 0.00E+00 -18.185 -13.125 6:40:50 215.75 185.652 3357.78 945.713 198.428 1217.95 1201.81 36.7392 0.00E+00 0.00E+00 -18.223 -13.125 6:41:00 215.687 185.527 3346.8 948.683 198.428 1218.33 1205.46 36.75 0.00E+00 0.00E+00 -18.685 -13.084 6:41:10 215.687 185.402 3355.94 933.742 212.129 1227.93 1203.83 36.75 0.00E+00 0.00E+00 -18.872 -13.125 6:41:20 215.625 185.339 3307.68 939.747 212.129 1235.86 1205.46 3S.75 0.00E+00 0.00E+ 00 -18.723 -13.187 6:41:30 215.625 185.089 3331.9 942.735 212.129 1250 1205.46 36.75 0.00E+00 0.00E+00 -18.848 -13.187 6:41:40 215.562 184.902 3382.08 930.725 183.708 1257.79 1255.53 36.7812 0.00E+00 0.00E+00 -18.997 -1325 6:41:50 215.5 184.839 3373.01 933.742 212.129 1274.75 1251.56 36.7392 0.00E+00 0.00E+00 -19.185 -13.312 6:42:00 215.5 184.652 3397.89 936.749 183.708 1288.47 1273.22 36.7187 0.00E+00 0.00E+00 -19.41 -13.271 6:42:10 215.375 184.589 3353.66 951.643 198.428 1316.96 1279.34 36.6875 0.00E+00 0.00E+00 -19.435 -13.334 6:42:20 215.375 184.464 3375.28 939.747 212.129 1289.99 1305.04 36.6875 0.00E+00 0.00E+00 -19.623 -13.334 6:42:30 215.312 184.339 3394.07 921.615 212.120 1289.6 1291.12 36.6875 0.00E+00 0.00E+00 -19.623 -13.438 Millstone Unit 2,2/22/96 5/10/96 Page 9 Cooldown Event Review

Attrchment C 8.7 Millstone Unit 2 February 22,1996 PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2S1657# 2Sf657= Y CoolRate X CootRate 6:42:40 215.312 184.402 3369.6 945.713 212.129 1288.47 1296.03 36.6875 0.00E+00 0.00E+00 -19.56 -13.334 6:42:50 215.25 184.527 3322.7 975 198.428 1308.03 1259.34 36.6562 0.00E+00 0.00E+00 -19.185 -13.375 6:43:00 215.187 184.589 3391.12 948.683 212.129 1299.04 1296.03 36.625 0.00E+00 0.00E+00 -18.748 -13.438 6:43:10 215.187 184.714 3406.89 945.713 212.129 1300.54 1293.01 36.6562 0.00E+00 0.00E+00 -18.686 -13.438 6:43:20 215.062 184.777 3423.7 930.725 212.129 1293.01 1280.87 36.6562 0.00E+00 0.00E+00 -18.373 -13.563 6:43:30 215.062 184.777 3378.68 930.725 224.998 1322.88 1267.07 36.6562 0.00E+00 0.00E+00 -18.248 -13.5 6:43:40 215 184.777 3425.94 939.747 212.129 1315.47 1316.96 36.6875 0.00E+00 0.00E+00 -18.123 -13.562 6:43:50 215 184.714 3406.89 939.747 198.428 1353.53 1315.47 36.6875 0.00E+00 0.00E+00 -17.936 -13.562 6:44:00 214.937 184.652 3428.17 927.698 198.428 1339.02 1299.04 36.7187 0.00E+00 0.00E+00 -17.873 -13.563 6:44:10 214.875 184.527 3432.2 939.747 212.129 1367.51 1315.09 36.7392 0.00E+00 0.00E+00 -17.81 -13.562 6:44:20 214.875 184.402 3434.43 933.742 212.129 1354.59 1313.61 36.7704 0.00E+00 0.00E+00 -17.748 -13.562 6:44:30 214.75 184.214 3418.1 951.643 212.129 1339.02 1343.39 36.7812 0.00E+00 0.00E+00 -17.936 -13.646 6:44:40 214.687 184.277 3397.89 927.698 198.428 1328.77 1333.17 36.8125 0.00E+00 0.00E+00 -17.935 -13.75 6:44:50 214.687 184.277 3386.6 939.747 212.129 1353.53 1312.5 36.8125 0.00E+00 0.00E+ 00 -17.998 -13.75 6:45:00 214.586 184.402 3410.26 933.742 224.998 1340.48 1330.24 36.8437 0.00E+00 0.00E+00 -17.81 -13.789 6:45:10 214.562 184.402 3438.2 945.713 212.129 1396.14 1336.1 36.8437 0.00E+00 0.00E+00 -17.748 -13.813 6:45:20 214.5 184.464 3487.95 915.491 212.129 1393.34 1347.74 36.8437 0.00E+00 0.00E+00 -17.873 -13.875 6:45:30 214.437 184.214 3471.45 927.698 212.129 1430.69 1340.48 36.8437 0.00E+00 0.00E+00 -17.936 -13.938 6:45:40 214.437 183.902 3455.97 930.725 212.129 1425.22 1362.16 36.875 0.00E+00 0.00E+00 -17.998 -13.834 6:45:50 214.375 183.715 3513.1 945.713 212.129 1457.74 1433.42 36.8437 0.00E+00 0.00E+00 -18.122 -13.834 6:46:00 214.312 183.652 3512.01 930.725 212.129 1446.98 1434.78 36.8125 0.00E+00 0.00E+00 -18.185 -13.938 6:46:10 214.25 183.5 3500.66 939.747 212.129 1468.06 1438.5 36.7704 0.00E+00 0.00E+00 -18.275 -14 6:46:20 214.187 183.34 3427.05 927.698 212.129 1452.37 1451.02 36.7812 0.00E+00 0.00E+00 -18.31 -13.959 6:46:30 214.125 183.34 3438.2 933.742 212.129 1485.61 1419.73 36.7812 0.00E+00 0.00E+00 -18.372 -14.021 6:46:40 214.062 183.34 3473.21 936.749 212.129 1458.72 1457.38 36.7812 0.00E+00 0.00E+00 -18.247 -14.063 6:46:50 214 183.402 3486.85 948.683 198.428 1465.75 1446.98 36.7812 0.00E+00 0.00E+00 -18.185 -14.084 6:47:00 214 183.562 3516.37 936.749 212.129 1486.92 1426.59 36.7812 0.00E+00 0.00E+00 -17.9 -13.937 6:47:10 213.937 183.59 3515.93 942.735 198.428 1486.57 1423.48 36.75 0.00E+00 0.00E+00 -17.81 -14 6:47:20 213.836 183.652 3521.81 966.307 183.708 1480.34 1434.78 36.75 0.00E+00 0.00E+00 -17.748 -14.06 6:47:30 213.875 183.715 3420.34 942.735 198.428 1477.7 1442.92 36.7187 0.00E+00 0.00E+00 -17.685 -13.959 6:47:40 213.812 183.715 3492.33 930.725 212.129 1484.29 1410.06 36.7187 0.00E+00 0.00E+00 -17.622 -14.022 6:47:50 213.75 183.715 3530.49 939.747 212.129 1 <65.75 1442.92 36.7187 0.00E+ 00 0.00E+00 -17.685 -13.959 6:48:00 213.75 183.59, 3540.24 933.742 224.998 1476.38 1446.98 36.75 0.00E+00 0.00E+00 -17.747 -14 6:48:10 213.687 183.59l 3464.82 933.742 212.129 1507.79 1465.75 36.7187 0.00E+00 0.00E+00 -17.747 -13.938 Millstone Unit 2,2/22/96 5/10/96 Page 10 Cooldown Event Review

l 1

Att chment O 8.7 l Millstone Unit 2 l Fetnuary 22,1996, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 251657# 2S1657= Y CooiRate X CoolRate j 6:48:20 213.586 183.59 3542.4 939.747 212.129 1498.7 1463.09 36.7187 0.00E+00 0.00E+00 -17.747 -14.039 6:48:30 213.562 183.465 3435.5 _4 936.749 212.129 1498.34 1452.01 36.7187 0.00E+00 0.00E+00 -17.685 -14

6

48:40 213.5 183.402 3481.36 939.747 212.129 1516.83 1449.68 36.7187 0.00E+00 0.00E+00 -17.623 -14.062 6:48:50 213.5 183.402 3505.46 951.643 212.129 1505.2 1463.09 36.6875 0.00E+00 0.00E+00 -17.373 -13 S 59 6:49:00 213.437 183.402 3492.33 930.725 212.129 1541.1 1494.78 36.6562 0.00E+00 0.00E+00 -17.123 -13.96 6:49:10 213.375 183.402 3517.46 936.749 198.428 1574.95 1476.38 36.6875 0.00E+00 0.00E+00 -16.998 -14 6:49:20 213.273 183.34 3572.09 945.713 183.708 1562.15 1494.43 ~v3.6875 0.00E+00 0.00E+00 -16.997 -14.102 6:49:30 21325 183.09 3559.65 942.735 212.129 1571.23 1469.75 36.6875 0.00E+00 0.00E+00 -17.247 -14.022 6:49:40 213.25 182.965 3526.15 930.725 224.998 1565 1505.2 36.6875 0.00E+00 0.00E+00 -17.31 -13.959 6:49:50 213.25 182.965 3536.99 936.749 224.998 1579.9 1519.41 36.6875 0.00E+00 0.00E+00 -17.372 -13.959 6:50:00 213.187 182.965 3600.28 927.698 198.428 1592.22 1509.09 36.6875 0.00E+00 0.00E+00 -17.372 -14 6:50:10 213.125 182.902 3584.3 948.683 212.129 1588.53 1542.37 36.6875 0.00Ev00 0.00E+00 -17.31 -14.062 6:50:20 213.062 182.84 3592.83 936.749 212.129 1599.56 1532.21 36.6875 0.00E+00 0.00E+00 -17.247 -14.125 6:50:30 213 182.715 3586.43 924.662 212.129 1623.8 1551.21 36.6562 0.00E+00 0.00E+00 -17.497 -14.125 6:50:40 213 182.777 3618.31 963.392 224.998 1640.55 1563.75 36.6875 0.00E+00 0.00E+00 -17.31 -14.062 6:50:50 212.937 182.84 3611.96 951.642 198.428 1654.78 1516.83 36.6562 0.00E+00 0.00E+00 -17.185 -14.063 6:51:00 212.875 182.777 3623.6 915.491 212.129 1648.86 1556.24 36.6562 0.00E+00 0.00E+00 -17.31 -14.125 6:51:10 212.812 182.652 3594.96 942.735 212.129 1642.93 1530.93 36.6142 0.00E+00 0.00E+00 -17.56 -14.188 6:51:20 212.75 182.715 3603.47 924.662 212.129 1648.86 1543.64 36.625 0.00E+00 0.00E+00 -17.497 -14.187 6:51:30 212.75 182.777 3627.82 936.749 212.129 1617.77 1544.9 36.625 0.00E+00 0.00E+00 -17.435 -14.125 6:51:40 212.687 182.84 3565.02 927.698 198.428 1658.31 1598.34 36.625 0.00E+00 0.00E+00 -17.435 -14.188 6:51:50 212.625 182.777 3600.28 936.749 212.129 1645.31 1582.37 36.625 0.00E+00 0.00E+00 -17.41 -14.187 6:52:00 212.625 182.715 3646.77 942.735 212.129 1678 21; 1600.78 36.625 0.00E+00 0.00E+00 -17.372 -14.187 6:52:10 212.562 182.652 3663.52 951.643 212.129 1675.ta 1611.72 36.6562 0.00E+00 0.00E+00 -17.373 -14.25 6:52:20 212.5 182.59 3655.15 921.615 212.129 1705.92 1578.67 36.6562 0.00E+00 0.00E+00 -17.185 -14.187 6:52:30 212.437 182.465 3630.99 930.725 212.129 1685.18 1587.3 36.6562 0.00E+00 0.00E+00 -17.123 -14.272 6:52:40 212.375 182.402 3563.95 942.735 212.129 1716.19 1646.49 36.625 0.00E+00 0.00E+00 -17.16 -14.334 6:52:50 212.273 182.465 3649.91 930.725 198.428 1713.91 1594.67 36.625 0.00E+00 0.00E+00 -16.998 -14.414 6:53:00 212.273 182.402 3595.59 915.491 212.129 1705.58 1623.46 36.6142 0.00E+00 0.00E+00 -16.998 -14.352 6:53:10 212.25 182.402 3580.02 927.698 224.998 1687.5 1616.56 36.6562 0.00E+00 0.00E+00 -16.938 -14.375 6:53:20 212.125 182.465 3654.72 936.749 212.129 1706.73 1589.42 36.6562 0.00E+00 0.00E+00 -16.748 -14.437 6:53:30 212.187 182.465 3659.34 930.725 198.428 1672.39 1576.19 36.6562 0.00E+00 0.00E+00 -16.685 -14.313 6:53:40 212.023 182.465 3519.2 933.742 212.129 1597.99 1548.34 36.6767 0.00E+00 0.00E+00 -16.748 -14.477 6:53:50 212 182.527 3402.39 933.742 212.129 1511.67 1394.74 36.6562 0.00E+00 0.00E+00 -16.748 -14.5 Millstone Unit 2,2/22/96 5/10/9S Page 11 Cooldown Event Review

Attechment # 8.7 .

Millstone Unit 2 February 22,1996. PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2S1657# 2S1657= Y Coo l Rate X CootRate 6:54:00 212 182.902 3322.7 936.749 l 212.129 1286.95 1282.39 36.6875 0.00E+00 0.00E+00 -16.373 -14.437 6:54:10 211.937 183.59 3271.61 939.747 198.428 1130.2 1107.5 36.6875 0.00E+00 0.00E+00 -15.685 -14.5 6:54:20 211.875 184.902 -3189.85 927.698 198.4 3 972.271 976.281 36.6875 0.00E+00 0.00E+00 -14.373 -14.562 6:54:30 211.812 186.589 3052.48 936.749 972.111 918.558 947.859 36.6562 0.00E+00 0.00E+00 -12.624 -14.563 6:54:40 211.75 188.339 3126.82 930.725 980.751 939.581 949.917 36.6875 0.00E+00 0.00E+00 -10.874 -14.625 6:54:50 211.75 189.401 3150.78 927.698 977.88 943.256 924.435 36.6767 0.00E+00 0.00E+00 -9.874 -14.625 6:55:00 211.75 189.714 3358.22 936.749 957.535 1200.59 1116.29 36.6562 0.00E+00 0.00E+00 -9.499 -14.522 6:55:10 211.75 189 3437.09 921.615 942.735 1227.93 1192.42 36.6875 0.00E+00 0.00E+00 -10.213 -14.562 6:55:20 211.75 186.714 3320.39 942.735 951.643 1308.03 1263.98 36.6875 0.00E+00 0.00E+00 -12.499 -14.5 6:55:30 211.711 183.937 3388.42 966.307 933.742 1289.99 1235.46 36.6875 0.00E+00 0.00E+00 -15.151 -14.498 6:55:40 211.75 180.527 3206.61 927.698 918.558 1155.83 1121.52 36.6875 0.00E+00 0.00E+00 -18.498 -14.437 6:55:50 211.711 177.34 3123.93 942.735 906.228 1065.74 1022.72 36.6454 0.00E+00 0.00E+00 -21.748 -14.476 6:56:00 211.774 174.966 3105.94 933.742 912.414 910.013 922.801 36.6454 0.00E+00 0.00E+00 -24.122 -14.413 6:56:10 211.875 174.091 3114.56 912.414 918.558 847.791 866.025 36.6562 0.00E+00 0.00E+00 -25.059 -14.147 6:56:20 211.899 174.591 3042.43 939.747 909.326 734.208 788.095 36.625 0.00E+00 0.00E+00 -24.559 -14.123 6:56:30 211.937 175.591 3052.48 942.735 918.558 723.489 760.345 36.6562 0.00E+00 0.00E+00 -23.559 -14.125 6:56:40 212 176.903 3060 945.713 900 731.543 765.465 36.6875 0.00E+00 0.00E+00 -22.31 -14 6:56:50 212 177.59 3162.13 939.747 906.228 877.229 861.503 36.6875 0.00E+00 0.00E+00 -21.498 -14 6:57:00 212.023 177.25 3188.65 939.747 909.326 924.915 892.678 36.75 0.00E+00 0.00E+00 -21.775 -13.914 6:57:10 212.086 174.903 3181.44 945.713 893.728 931.228 892.678 36.7392 0.00E+00 0.00E+00 -24.06 -13.789 6:57:20 212.148 172.341 3212.13 942.735 903.119 945.324 928.651 36.7704 0.00E+00 0.00E+00 -26.372 -13.727 6:57:30 212.312 168.904 3145.14 939.747 903.119 954.021 929.129 36.7812 0.00E+00 0.00E+00 -29.809 -13.5 6:57:40 212.437 166.342 3226.84 957.535 906.228 966.226 912.157 36.8125 0.00E+00 0.00E+00 -32.308 -13.272 6:57:50 212.5 164.217 3219.71 927.698 906.228 945.796 943.729 36.8437 0.00E+ 00 0.00E+00 -34.371 -13.209 6:58:00 212.562 162.842 3163.34 945.713 912.414 949.517 890.487 36.8437 0.00E+00 0.00E+00 -35.683 -13.085 6:58:10 212.625 162.217 3014.63 927.698 903.119 790.569 824.431 36.8437 0.00E+00 0.00E+00 -36.183 -13.062 6:58:20 212.625 162.655 2967.27 933.742 912.414 728.868 785.612 36.875 0.00E+00 0.00E+00 -35.683 -13.022 6:58:30 212.625 164.467 3065.81 951.643 906.228 703.74 762.35 36.875 0.00E+00 0.00E+00 -33.871 -13.062 6:58:40 212.586 166.467 3041.99 942.735 900 703.74 746.822 36.875 0.00E+00 0.00E+00 -31.683 -12.998 6:58:50 212.523 168.529 3027.3 951.643 906.228 707.106 752.599 36.8437 0.00E+00 0.00E+00 -29.496 -13.061 6:59:00 212.523 169.966 2995.52 957.535 909.326 707.106 744.773 36.8437 0.00E+00 0.00E+00 -27.997 -13.061 6:59:10 212.562 170.841 3038.66 948.683 900 707.106 747.391 36.8437 0.00E+00 0.00E+00 -26.997 -13 6:59:20 212.5 171.216 3G21.79 939.747 909.326 752.033 780.075 36.8329 0.00E+00 0.00E+00 -26.559 -13.125 6 59:30 212.5 171.154 3092.35 957.535 903.119 780.624 783.122 36.8125. 0.00E+00 0.00E+00 -26.621 -13.125 Millstone Unit 2,2/22/96 5/10/96 Page 12 .

Cooldown Event Review

O Attachment # 8.7 ,

c itstone Unit 2 February 22,1Wd, PPC Cooldown Event Data Date-Time T351X T351Y F306 F6043 F6042 F3023 F3024 T6032 2St657# 2Sl657= Y CootRate X CcdRate 6:59:40 212.375 170.279 3081.19 951.642 906.228 757.772 800.39 36.8125 0.00E+00 0.00E+00 -27.621 -13.25 6:59:50 212.273 169.091 3058.31 951.643 915.491 775.052 794.954 36.7704 0.00E+00 0.00E+00 -23.872 -13289 7:00:00 212.086 168.091 3098.1 957.535 903.119 770.551 802.29 36.8125 0.00E+00 0.00E+00 -29.934 -13.498 7:00:10 211.899 167.217 3070.8 957.535 906.228 764.907 799.852 36.8329 0.00E+00 0.00E+00 -30.808 -13.623 7:00:20 211.687 166.529 3043.69 948.683 909.326 755.19 795.494 36.8125 0.00E+00 0.00E+00 -31.559 -13.335 7:00:30 211.562 166.029 3068.74 945.713 900 770.551 805.256 36.8125 0.00E+00 0.00E+00 -31.996 -14 7.00:40 211.25 165.779 3047.46 939.747 909.326 770.551 814.9 36.7704 0.00E+00 0.00E+00 -32246 -1425 7:00:50 211.062 165.529 3077.46 945.713 915.491 770.551 790.569 36.75 0.00E+00 0.00E+00 -32.621 -14.438 7:01:00 210.875 165.467 3094.83 957.535 896.869 762.909 807.678 36.75 0.00E+00 0.00E+00 -32.558 -14.625 7:01:10 210.586 165.342 3072.04 966.307 887.411 755.19 816.764 36.7392 0.00E+00 0.00E+00 -32.621 -14.873 7:01:20 210.399 165.279 3084.48 969.213 900 767.456 807.144 36.7079 0.00E+00 0.00E+00 -32.684 -14.976 7:01:30 210.187 165.279 3074.97 957.535 903.119 755.19 805.256 5 36.7187 0.00E+00 0.00E+00 -32.684 -15.188 7:01:40 2.09.937 165.217 3103.48 960.468 906.228 755.19 800.39 36.7187 0.00E+00 0.00E+00 -32.746 -15.438 7:01:50 209.625 165.154 3038.66 966.307 893.728 757.772 810.092 36.7187 0.00E+00 0.00E+00 -32.809 -15.687 7:02:00 209.274 165.154 3068.3 957.535 903.119 741.573 804.721 36.6875 0.00E+00 0.00E+00 -32.809 -16.038 7:02:10 209.062 165.092 3027.3 966.307 903.119 742.146 807.678 36.6875 0.00E+00 0.00E+00 -32.871 -16.25 7:02:20 208.812 165.092 3072.48 951.643 900 744.773 788.095 36.6562 0.00E+00 0.00E+00 -32.746 -16.335 7:02:30 208.625 165.092 3024.77 963.392 906.228 739.509 793 035 36.625 0.00E+00 0.00E+00 -32.746 -16.522 7:02:40 208.336 165.154 3039.48 957.535 906.228 730.964 792.494 36.6454 0.00E+00 0.00E+00 -32.684 -16.726 7:02:50 208.125 165.029 3028.56 972.111 912.414 739.509 793.035 36.6562 0.00E+00 0.00E+00 -32.746 -16.834 7:03:00 207.937 164.842 3056.24 969.213 909.326 736.863 800.39 36.6562 0.00E+00 0.00E+00 -32.746 -17.022.

7:03:10 207.812 164.654 3057.5 951.643 896.869 742.146 773.081 36.6562 0.00E+00 0.00E+00 -32.746 -17.188 7:03:20 207.587 164.467 3047.46 969.213 912.414 739.509 778.118 36.6562 0.00E+00 0.00E+00 -32.808 -17.31 7:03:30 207.5 164.217 3024.77 960.468 903.119 712.609 775.604 36.6562 0.00E+00 0.00E+00 -32.871 -17.397 7:03:40 207.399 164.092 3038.22 980.751 887.411 698.169 741.573 36.6562 0.00E+00 0.00E+00 -32.996 -17.476 7:03:50 207.312 164.217 2991.24 %0.468 912.414 686.888 741.573 36.6767 0.00E+00 0.00E+00 -32.808 -17.5 7:04:00 207212 164.404 2966.83 977.88 912.414 672.523 736.287 36.6767 0.00E+00 0.00E+00 -32.559 -17.6 7:04:10 207.125 164.75 3004.45 972.111 912.414 678.923 712.609 36.6875 0.00E+00 0.00E+00 -32.213 -17.687 7:04:20 207 165.092 2969.85 960.468 909.326 667.317 731.543 36.6562 0.00E+00 0.00E+00 -31.871 -17.75 7:04:30 206.875 165.342 2998.07 975 912.414 658.477 715.345 36.6562 0.00E+00 0.00E+00 -31.621 -17.875 7:04:40 206.75 165.404 3069.99 945.713 912.414 652.519 718.07 36.6562 0.00E+00 0.00E+00 -31.496 -18 7:04:50 206.625 165.717 3036.14 975 906.228 643.476 709.863 36.6875 0.00E+00 0.00E+00 -31.183 -18.062 7:05:00 206.5 165.967 2999.35 969.213 912.414 637.377 709.863 36.6875 0.00E+00 0.00E+00 -31.058 -18.187 7:05:10 206.375 166.154 3053.74 983.615 890.575 634.305 712.609 36.6875 0.00E+00 0.00E+00 -30.871 -18.147 Millstone Unit 2,2/22/96 5/10/96 Page 13 Cooldown Event Review

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