IR 05000352/1991001
| ML20029C281 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 03/12/1991 |
| From: | Bettenhausen L, Conte R, Williams J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20029C278 | List: |
| References | |
| 50-352-91-01OL, 50-352-91-1OL, 50-353-91-01OL, 50-353-91-1OL, NUDOCS 9103270111 | |
| Download: ML20029C281 (14) | |
Text
.
.
U. 5. NUCLEAR REGULATORY COMMISSION
REGION I
LIMERICK GENERATING STATION REQUALIFICATION PROGRAM EVALVATION Combined Report Nos.
50-352/91-01 (OL) and 50-353/91-01 (OL)
!
Facility Docket Nos.
50-352 and 50-353
Facility License Nos.
Philadelphi.a Electric Company P.O. Box 195
'
Wayne,PA 19087-0195
l Facility Name:
Limerick Generating. Station Units 1 and 2 Examination -'Dat e s :
January 15, 1991, through January 25, 1991 Examiners:
H. Williams, Sr. Operations Engineer S. Hanseil. Operations Engineer
'
J. Hanek, BWR Examiner, EG&G M. Parrish BWR Examiner, EG&G T. Eas11ck, Operations Engineer Requalification Examination Chief Examiner:
d#
3[8/9 l
/
A-
cian H. Williams, Sr. Operations Engineer date
'
o Reviewed by:
_b r pe>
~
Richard J. Conte, fj(tef
'date'
'
BWR Section, OperMions Branch l
Division of Reactor Safety
-
,
O Approved by: p-W -
-I l2 f
c
.
Lee H. Bettenhausen, Chief
/
da t'e Operations Branch Division of Reactor Safety
!
9103270111 910320 PDR ADOCK 050003S2 V
pyg
_
.._-
,_
_
!
...
,
!
'
$
...
EXECUTIVE SUMMARY i
Written and operating examinations were administered to six Reactor Operators
- 5 (R0s) and ten Senior Reactor Operators (SR0s)._ These operators were divided into three crews, which consisted of two operating and one staff crew. _The examinations were graded concurrently.by the NRC and the facility training staff. As graded by.the NRC and the facility, all three crews performed satisfactorily on the_ simulator portion of the examination.
Fifteen of the sixteen' licensed operators passed all portions of the examination.. One reactor
,
operator-failed the simulator portion of the examination during the first week
- of. examinations. He was provided with remedial training and given another
- i simulator examination which he; passed during the second week of examinations.
' The Limerick licensed operator training program met the criteria established _
.
in NUREG-1021, Rev. 6. - for a satisf actory program. Corrective. actions taken by
'
~the licensee,- as a : result of_-last year's unsatisfactory program determination, '
'
- were-reviewed and determined to be completed.
However, weaknesses" observed during this examination raised some coubts over the effectiveness of the-
,
corrective actions.
During the simulator portion of the examination, operators
<
~did not apply the communication Standards in which they were trained and expect ~' to operate by.. Team work was weak. There were a number of-instances
' of oper. tors failing to respond to ala*ms and not understanding plant response.
Further. several procedures were found to be inaccurate during the examination.
During the plant' walk-through examination, operators did not_ always follow their plant procedures.
Because of-these problems, NRC requested that the licensee do a.-self evaluation of their program and discuss the results with NRC after the facility. examinations-are completed in February.
P
-.
-
,..,.,mm.~,
,4..w,.
,,..%,.m.,
...,,..,_,e...,,m,,m.,,,,,y',,m_,,,,_.,..mm...,,%
.,_-.,,,_y,,%m.._..,,,,,,,_m.%,_,.,
,_y.._,__m,,m,
,
.
.
DETAILS 1.0 Introduction l
During the examination period, the NRC administered requalification examinations to 16 licensed operators (*6 R0's and *10 SR0's). Two operating crews and one staff crew were evaluated.
The examiners used the process and criteria described in NUREG 1021, " Operator Licensing Examiner Standards," Rev. 6. Section ES-601, "Admini:stration of NRC Requalification Program Euluations" and other 60X sections.
The examiners also reviewed the licen:,ee's corrective actions taken as a result of the unsatisfactory
,
licensed op ator requalification training program described in Combined Inspection Report 50-352/90-01(0L) and 50-353/90-01 (OL).
These correc-i tive actions are described in letters from G. M. Leitch to W. T. Russell i
dated February 7, March 9, and March 21, 1990.
'
An entrance meeting was held with the licensee on January 15, 1991, at the site. Those in attendance are identified in Attachment 1.
Licensee personnel contacted during the examination are also listed in Attachment 1.
Members of the combined NRC/ facility examination team, and the facility evaluators are also identified in Attachment 1.
- See NURFG-05a4, R3v. 1, "A Hsrd5cok of Acronyms and Initialisms."
2.0 Examination Results 2.1 Requalification Individual Results
_
,
The following is a summary of the individual examination results:
.
l RO l
SRO l
10iAt i
NRC Grading l
PAS $/ FAIL I PASS / FAIL l PASS / FAIL L
l
l
i l Written l
6/0 l
10/0 l
16/0 l
1 I
I I
I l Simulator-l 5/1
10/0 l
15/1 l
1 I
I l
l l Walk-through l 6/0
10/0 l
16/0 l
,
I I
l l
I 10verall l
5/1 l
10/0 l
15/1 l
J l
I I
I l
L
-_
_...
_
.
.
.
-_
_.
-
.
'
~
l R0 i
ik0 l
TOTAL I
Facility Grading l
PASS / FAIL I
PASS / FAIL
,1 PASS / Fall
[
l
I I
I l Written
6/0 l
10/0 l
16/0 l
i I
I l
l l
l l
l l
l Simulator l
5/1 l
10/0 l
15/1 l
I I
I I
l l
l
l l Walk-through l
6/0 l
10/0 l
16/0 l
l l
[
l l
l l
l l
l0verall l
5/1 l
10/0 l
15/1 l
1 I
I I
The reactor operator who failed the simulator portion of the examination was reexamined during the second week af ter remedial training and passed the se ond examination.
2.3 Generic Strengths and Weaknesses A summary of generic strengths and weaknesses noted by the NRL from the preparation, administration and grading of the requalification examinations is discussed below.
This information is being provided to aid the licensee in upgrading the requalification training program.
No licensee response is required.
2.3.1 Generic Strengths Control Board Operations - Operators were proficient at locating and
operating controls.
Staff SR0 performance in the dynamic simulator portion of the exam-
ination was good.
Operators were proficient in recognition of Transient Response
+
Irnplementing Procedure (TRIP) entry conditions.
Emergency Classifications made during the dynamic sin.ulator scenarios
- -
by the Shift Managers were timely and accurate.
2.3.2 Generic Weaknesses 2.3.2.1 Communications, Command and Control.
Operators did not follow the guidance provided in Operations Manual Chapter 6.2, " Verbal Communications Standards." This standard was upgraded, and operators were given special training on the standard.
Examples observed during this examination include:
l
.
l
'
.
L'
'
.
T
A shift supervisor did not inform his crew of an HPCI technical
i specification LCO or a core spray LCO.
i A shift supervisor did not inform his crew when entering and exiting i
.
=T-101 and T-99.
A shift manager gave directions to the Reactor Operator (RO) and
Chief Operator (CO) without informing the Shift Supervisor.
.
A shif_t supervisor asked for suppression pool temoerature and was
'
given air temperature rather than water temperature.
RO did not;tell the shift supervisor when all sump pumps were running i
or when he stopped coolant flow to the reactor vessel.
A shift manager and a shift supervisor used the TRIPS at the same I
- -
_
time but independent of each other.-
Shift Supervisors generally did not seek crew input to decision-
making.
Shift Supervisors generally oid not keep crew informed of plant
'
status.
.
Commands were given in very general statements without identifying
persons or ec,u % ment or when actions needed to be done.
12.3.2.2-Alarm Response, Event Diagnosis, and Understanding Plant Response.
_
Examples of weaknesses observed in this area are discussed below.
- A shift supervisor ' ordered all ECCS pumps secured with reactor water
level at about 10".
The crew had indications of a steam leak in the drywell. The CO secured all ECCS pumps, and the RO secured all
condensate pumps. HPCI and RCIC were isolated ~on low steam line
. pressure.
There was no injection into the reactor vessel for approximately three minutes.
.'
One crew' directed l reactor water highly-contaminated _with fission-
products'to the condenser for vessel level _ control. There was a Group I isolation due to high radiation in-the MSLs.
The-procedure for blowing down to the condenser did not require consideration of coolant activity.- This~ action could-have-resulted in an unmonitored
'
release ~and unnecessary radiation exposures.-
,
An operator reported he had level control with HPCI when HPCI was
isolated.
.An operator failed to anticipate a reactor vessel water. level
increase and secure the condensate pumps when reactor pressure was
,
decreasing and allowed the reactor vessel level to increase to over
_100 inches.
.
!-
j.L
'9 u
_, _ _ _ _ _
.
.
..
. -
,.. _. _
.
.
.
. _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _
_
_ _ _ _ _ _ _ - _
'
' '
.
i
?
An operator reported MSIVs were closed on a Group I isolation when
,
the B steam line was not isolated.
An operator acknowledged a "C" ESW motor overload alarm, but failed
. i
to recognize the pump trip for nine minutes. Operators tried to
restart the A and C ESW pumps with valid motor overcurrent annunci-g'
ators up. Operators failed to take appropriate actions for loss of
~
'A' ESW loop flow.
<
One crew secured the CRD pump with reactor pressure at 650 psig,
believing its operation would affect stable RCIC operations. With CRD secured the control rod drives would. not have cooling flow.
One crew did not recognize a failure of RWCU to isolate.
- An operator acknowledged a RBM upscale alarm but did not take
corrective actions.
On'the open. book written' examination, three of six operators did not
know the-operator actions for plant conditions requiring the use of 1(1) OT-101, "High Orywell Pressure" and'(2) ON-104, " Control Rod Problems."
' 2.3.2.3'
Procedure Compliance.
Weaknesses observed with procedure. compliance are discussed below.
A shift' supervisor. entered.T-101 and T-102 (0/W pressure 28 psig),
R but did not monitor containment parameters' for 'the next ten minutes.
>
During the static-examination, three of seven SRO missed questions on
applying technical: specification LCO's and for determining-reporting requirements,-
,
AnLoperator-failed to open HPCI lube oil cooling water supply valve
- -
~
,
~
HV-56-IFDS91as required by procedure $55.1.D, "HPCI System Full Flow-
Functional Test."
An operator failed.to open' disconnect 20A-20 as required by S94.2.A.
-
- -
" Bypassing-and Removing the A RPS and UPS Static-Inverter-from
.
Service."-
L*.
-Two; operators-failed to place the MSIV hand switches to the closedL
-
position when' resetting.a Group 7A isolation as required by GP-8.3,
" Primary and Secondary Containment Isolation Verification and Reset."
An operator did not simultaneously open the steam supply -and start
.the auxiliary'eam supply, then went back and' read the procedure; then oil pump as required.by Procedure S55.1.0.
opened the st
. Rather. he-started the; auxiliary 1 oil pump.
.
t
..
.,,9m.
f we y e
s g e e g -- t
,'wed'5..eydy. e r+
-e g + 9 g-
.y F
T
&
'w'W"'-5W'***-'M wtWT*
FNv"-7"P'WS'9-
'"
"''"t'--WWww*'8'""'**""'
- ""'"#*#
- ""'-"-^
-"-""" "-""-
'
w,
.,-
l
.,
,
2.4 Procedure Adequacy
- During the excmination, the following procedure adequacy concerns were
,
discovered.
'
An operator failed to throttle open the injection valves during
initiation of containment. spray in violation of a caution in the TRIP procedure (T-102).
The caution was not in 551.8.F, " Suppression Pool
and Drywell Spray Operation."
,
The procedure for reactor vessel blow down to the condenser did not
,
address. reactor coolant radioactivity, especially for failed fuel situations. The licensee began procedure changes to address this-issue during the. examination period.-
,
3.0 _Requalification Drogram Evaluation Results The facility program for licensed operator requalification training met
,
the criteria' established in ES-601, Administration of NRC Requalification
- Program Evaluations" i_n the following areas:
paragraph C.2.b(1)(a b The facility grading must be as conservative
- as NRC grading'on at least 90 percent of the pass / fail decisions for
-
each section of the exam. There was 100 percent agreement on each'
,
section of the exam.'
Paragraph C.2.b(1)(b).. At-least 75 percent of all operators pass the
$
- *
examination, not including. individuals who participate in the simu-
,
.lator examination only..The pass rate was 94 percent.
.
~
' PsagraphC.2.b(1)(c).
No more than one-third of the crews evaluated fail.the simulator exam. There were no crew failures.
- ParagraphC.2.b(2)..If.three.or'more of the following apply, then the program is ' unsatisfactory.. However, one or more'could result in an unsatisfactory program.
- (1) ' Facility evaluators do not concur with NRC evaluators on all unsatisfac-tory crew evaluations. There were no unsatisfactory crew evaluations.
J (2)- Facility; failed.to' train and evaluate operators in all position-permitted
'
by their license. -No problem was found in this area.
-
-
(3) More than one facility evaluator is unsatisfactory, There were'no un-
- satisfactory evaluators.
>
'
(4)' There are lack of r dministrative controls to preclude licensed operators a
with " inactive" licenses from performing licensed duties.- No problem was
- identified in this area.
,
l
.
- -
r..
--s,oi..
.s..
,,.~,,6,*m,w.,-#m.+.a
--v-,-*--,-..,-nr-,,,..r,,w,.vn,,...w.,m,,y,..-,.
.
.,m-,---
,,ry,-
vi,,,
,,
_,-w..
,,,.--,,,.%% T e
(5) There is a lack of quality control on the examination bank in that signi-ficant changes were made to more than 10 percent of questions on the written examination. No changes were made to the final written examination.
(6) Facility failure rate is excessive relative to NRC failure rate.
There was no difference in failure rate.
The Limerick licensed operator training program met the criteria established in NUREG-1021, Rev. 6, for a satisfactory program.
Corrective actions taken by the licensee, as a result of last year's unsatisfactory program determina-tion, were reviewed and determined to be completed.
However, weaknesses observed during this examination raised some doubts over the effectiveness of the corrective actions. The program will remain unsatisfactory until all identified corrective actions agreed upon by the NRC for restoring the program to satisfactory status and related NRC follow-up are completed.
This report documents satisfactory completion of sn NRC administered requalification exami-nation of 16 individuals.
4.0 Requalification Examination Preparation The reference material that was submitted by the licensee met the guide-lines of ES-601-2. The material included a sample plan, a 520 question examination bank for the classroom portion of the written examination, 42 static simulator examinations, a 441 question examination bank for the static simulator examination, 32 dynamic simulator scenarios, 111 JPMs, and a 337 question bank for the JPMs.
'The written examinations were reviewed and after corrections were found to be acceptable.. The exa:aination sampled a good cross section of the in-formation covered during the requalification year. A number of questions needed to be changed to ensure the question solicited the correct answer, or conformed with the guidelines of NUREG/BR-0122.
The NRC examination team selected the simulator scenarios for the dynamic
'
simulator examination from the bank provided by the facility and reviewed the static simulator scenarios chosen by the facility.
Both the dynamic and static scenarios were revised to include equipment malfunctions and technical specification actions to conform with ES-602 and ES-604 guide-lines. The scenarios were reviewed during the on-cite validation period.
The examination team reviewed 24 JPM's proposed by the facility.
Five of the JPMs weie common JPMs, and the remaining 19 were randomly distributed'
among the-operators examined.
Change! 'o the JPMs included:
revision of
.
steps marked critical to non-critical, replacing a JPM, correcting compo-nent labelling and procedure errors, and revising JPM questions to conform to the guidelines of ES-603.
t
,
.. -
-, _,.
, - -....
-,.,,, - -
. -.
,
,
.
5.0' _Requalification Examination Administration The facility chose to videotape the dynamic simulator portion of the examination. These tapes proved to be useful resource in confirming the grading of certain scenarios.
Except for simulator modeling problems described in the simulator fidelity report, no major problems were en-
-
countered during this portion of the examination.
The JPM portion of the examination incurred unexpected problems eariv in the examination; but, after these were corrected, it ran smoothly. Two JPMs had the same follow-up question.
This was identified by the NRC and corrected before use in the walk-through.
Procedural changes made after the on-site review impacted on JPM write-ups.
Evaluator prompting was an initial concern; but, af ter the NRC identified the problem, it was corrected very efficiently.
In some cases, cues were given when they should not have been and not given when they should have been. Overall, these problems arose early during-the JpM portion of the examination and relate to the mechanics of preparing and giving the walk-throughs.
The second week of JPM's were conducted without problems.
The pass / fail performance was not affected by these problems, but a better planned walk-through examination could have reduced operator stress.
The written portion of the examination was conducted without problems.
The licensee was very careful to time validate the written examination.
All operators completed the examination in the allotted time.
,
Good cooperation between the examination teams allowed any problems that arose to be resolved in a timely manner and prevented them from affecting the examination.
>
'
6.0 Follow-up_on Previously identified Requalification program Deficiencies and Corrective Actions (Unresolved item Nos. 352 and 3SF90-01-02, Open)
The requalification examination conducted during the week of January 29, 1990, determined that Limerick's requalification training program was unsatisfactory. The unsatisfactory program was considered unresolved Item 352 and 353/90-01-02.
The results of the examination and weaknesses were documented _in Combined Inspection Report 50-352/90-01 (OL)
and 50-353/90-01 (0L). The licensee described corrective actions in letters to W. T. Russell, NRC, dated February 7, March 9, and March 21, 1990.
The completion of these corrective actions was reviewed during this report period. All corrective actions were satisfactorily completed.
However, because of observations made during this requalification exami-nation, some questions were raised over the effectiveness of the correc-
,
tive actions. This unresolved item remains open until the NRC is convinced that the corrective actions taken by the licensee were effective in improving performance in the arcas identified as weaknesses in inspec-tion report 90-01.
<
_
_
_ __
__
.
7.0 Exit Meetina An exit meeting was held in the licensee's office on January 30, 1991.
Personnel in attendance are listed in Attachment 1.
The NRC results of
!
the examination and review of follow up corrective actions were presented.
Generic strengths and weaknesses were discussed.
The licensee was informed that NRC would observe their administered simulator exams during the remainder of the cycle to better understand the weaknesses observed during the NRC administered examinations. Also, the NRC would administer reexaminations to any failures of the licensee's examination.
The NRC requested that the licensee evaluate the effectiveness of their corrective actions after the current 6 week examination cycle and meet with NRC to discuss their evaluation.
Attachments 1.
Persons Contacted 2.
Requalification Examination Test Items 3.
Simulator Fidelity Report
.
..
--
--
.-
- -. -.
.--
- - - -
.-....
,
,
Attachment 1 persons Contacted J. Allison, Requalification Instructor (1,4)
J. Armstrong, LGS, Assistant Superintendent - Operations (1,2)
M. Baughman, Requalification Instructor (1, 3, 4)
V. Cvictniewicz, LGS Superintendent - Training (1,2)
J. Doering, LGS Plant Manager (2)
5. Dufort, Requalification Instructor (1,4)
R. Helt, Supervisor (2)
L. Hopkins, LGS, Superintendent - Operations (2)
R. Krich, Licensing Branch Head (2)
G. Leitch, Vice President Limerick (2)
R. Lisko, simulator Support Supervisor (2)
R. Monaco, Lead Instructor (1,2)
D. Mores, Operations Instructor (2)
R. Nunez, Operations Training Supervisor (1,2,3)
W. Stanley, Shif t Manager (1,3)
G. Stewart, Engineer-Supervisor, Licensing (2)
'
W. Tracey, Requalification Instructor (4)
Nuclear Regulatory Commission L. Bettenhausen, Chief, Ops Br. DRS (2)
L. Doerflein, Chief, RPS 2B, DRP (2)
J. Hanek, BWR Examiner, EG&G (1,3)
S. Hansell, Operations Engineer (1,2,3)
T. Kenny, SRI / Limerick (2)
W ' Lanning, Deputy Director, DRS (2)
M. Parrish, BWR Examiner, EC&G (1,3)
J. Williams, Senior Operations Engineet- (1,2,3)
Notes:
(1) Attended Entrance Meeting, January 15, 1991 (2) Attended Exit Meeting, January 30, 1991 (43) Member - Combined Facility /NRC Extmination Team 1 ) Facility Evaluator
.
._
.., _ _
--_.-
_.
.-
_
G
.
Attachment 2
_REQUALIFICATION EXAMINATION TEST ITEMS Written Examination -Part_A, Week One - SSE-17 with 10 questions of value 1 each S5E-22 with 10 questions of value 1 each Week Two SSE-25 with 10 questions of value 1 each
'
SSE-32 with 10 questions of value 1 each Written Examination - Part B QNUM/QVAL 91-RO-1 91-SRO-1 91-R0-2 91-SRO-2 1/1
643 164 262 2/1
22 116 116 3/1 433 433 246 690 4/1 424 424 118 118
,
5/1 161 161 442 442 6/1 110 110 434 434 7/1
52 111 111 8/1 225 225 107 107 9/1 511 511 103 103 10/1
17
216 11/1
29
85 12/1 125 125
56 13/1 162 221 663 663 14/1 221 129
32 15/1 129 143
31 16/1 143 217 290 254 17/1
54
12 18/1 167 418 315
19/1 418 104
313 20/1 104 162 241
..-
.
.
-
- -
- - - -
_.
._
- _
-
__. -.
.
'
Job Performance Measures (JPM)
LOJPM(common)
23 Initiate Containment Spray 112 Manual HPCI Start 22 Resetting a 62% Recire System Runback 64 De-energization of Scram Solenoids *
103 B ESW Pump Start From 4KV Emergency Swite
' * *
Week 1 19 Initiate Suppression Pool Spray 16 Shutdown of an Operating D/G 108 Placing a RFP Inservice 106 Bypassing an RPS Inverter *
33 Place RHRSW Inservice from the RSDP*
2-Scram Report 83 Group VII A Isolation Reset 105 Bypassing Rx Enclosure HVAC Isolation *
115 Alternate DC Power to ADS *
123 Vent DW Using 6" line*
,
Week 2 110 D14 Start and Load 18 Removing a RFP from Service 70 Placing a RPS Inverter Inservice *
32 Placing RHR in Suppression Pool Cooling at REDP*
109 Maximize CRD Flow 5 Reset a Group III Isolation 125 RCIC Low Steam Line Pressure Isolation Bypass *
102 Manual Isolation and Vent of Scram Air Hdr a 119 Supplying IA to PCIG*
- JPMs performed in plant l
Dynamic Simulator Examination SES-03A Steam line rupture in the drywell SES-09 Loss of Off-site power SES-11 Recirc Loop Failure SES-13 MSL leak outside containment SES-14 Turbine trip at power, ATWS SES-20 MSL Rupture outside containment SES-27 RPS failure, MSIV closure, loss of high pressure feed, small steam leak SES-30 Turbine trip SES-31 High leakage in DW, loss of high pressure' feed SES-33 DBA-LOCA, failure of ADS /SRVs SES-06 Scram with stuck CRs - retake SES-07 Generators fault, scram, BPV f ail open - retake
-. -
-..
- -.- -
, - -. -.. __-. -.
_ - - -
,
.,
- >
.
Attachment 3 SIMULATION FACILITY REPORT
,.
Facility Licensee:
Philadelphia Electric Company, Limerick Generating Station Facility Docket No.: 50-352 and 50-353
- Requalification Examination Administered on: January 15 through January 25, 1991
- This' form is to be used only to report observationt,.
These observations do not constitute audit or inspection findings and are not, without further verification and review, indicative of non-compliance with 10 CFR 55.45(b).
These observations do not affect NRC certification or approval of the simulation facility.other than to provide information which may be used_in future evaluations.
No: licensee action is required in response to these observations.
During the conduct of the-simulator portion of the operating tests, tht following' items wero' observed (if none, so state):
ITEM-DESCRIPTION OFF GAS, With a 50% fuel' failure the B MSL Rad Monitor decreased
- STACK & MSL
- after an initial increase. 'The A, C, & D MSL Rad Monitors LRad Monitors were constant. The 8 MSL had failed to isolate as part of
'
the scenario. There was no stack monitor radiation
.
increase of. concern and the levels were back to normal in
!
'
about 10 minutes.
Off gas radiation levels peaked at 300 mR/hr acd-decreased to norma 11after about 7 minutes.
Loss of-ESW'(A)
Cooling
~
_
A complete-loss of-A ESW cooling to all channel "A and C"
,
ECCS systems-and the #11 and'#13 diesels occurred.
_The
'ARHR pump was. running in the' suppression pool cooling
'
mode-and.the #11 diesel generator was carrying.about.2500
KW.. Ten-minutes after'the loss of cooling there was still'
no high temperature alarms or component trips,
'
a (
'
,4
.,,..,,
~.,~,
n
..,..___. -