IR 05000352/1990080
| ML20059N133 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 09/28/1990 |
| From: | Bettenhausen L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Danni Smith PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 9010100140 | |
| Download: ML20059N133 (2) | |
Text
August 10, 1990
SUBJECT:
Lirruick _ Generating Station', Units = 1. and 2 '
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Response to NRC Unresolved Items Identified in Inspection Report Nos. 50-352/90-80 and:50-353/90-80
Dear Sirs
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t Attached is Philadelphia Electric Company';s-reply to a request
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for a written response to NRC Inspection Report Nos. 50-352/90-80 and
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50-353/90-80 for Limerick Generating Station'(LGS), Units 1 andD2.
- NRC letter dated July 3, 1990, transmitted'the Inspection Report which covered the Transient Response Implementation Plan.(TRIP) procedures.
L This letter requested that we respond-to the unresolved _ items b
identified in the inspection report within 30 days.of receipt of th'e.
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report.
We received the report'at LGS'on July 13,fl990.
The Attachment to this-letter provides our response to the= unresolved j
ltems as well as the other concerns identified.throughout.'the.
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Inspection Report.
Specifically, this response.idet.tifies'the short
term actions which have been taken to resolve certainiof.the concerns described in the Inspection Report.
The long term actions to resolve the remaining concerns wil'1 be determined by December 31, 1990, and provided in a supplement to this response by' January 30, 1991, t
If you have any questions or require additional information, please do not hesitate to contact us.
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Very t y
ours,
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DCS:cah
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Attachment-cc:
T. T. Martin, Administrator, Region I, USNRC-l T. J. Kenny, USNRC Senior Resident Inspector, LGS
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Attachment-
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P ge 1 of 10:
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In2paction Raport 50-352,.353/90-80-
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'Limerick Generating Station,EUnitsl1 and 2
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kesponse-to.NRC Unresolved' Items Identified'in
. Inspection Report Nos.. 50-352/90-80 and'50-353/90-80
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The cover letter that'transmitte'd NRC' Inspection Report Nos.
50-352/90-80 and 50-353/90-80 requested that we providerour;shortland.
j long term actions relative to the unresolved items identified inithe-
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Executive. Summary.
The two unresolved items are 352 and 353/90-80-01'
and.352 and 353/90-80-02.
BelowLisLour responsesto each of these unresolved:ltems.'
Additionally, we have provided ourLresponse to_the-other concerns identified;throughout the' report'.
Each item.is
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addressed below in the order.that they appeared 11n the Details section of the report.
The'Short Term actions (designated ST) make certain enhancements in.
the Plant Specific Technical Guideline (PSTG):and. Transient Response Te PSTGs and affected TRIP
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Implementation Plan (TRIP) procedures.
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procedures.were all revised, reviewed by.the Plant' Operations Review Committee (PORC).and approved by the' Operations and Technical Staffs before July 15, 1990.
Implementation and the.necessary training of these changes.is expected.to be completed.by: September 15, 1990.
Long Term > items (designated LT).will be reviewed and appropriate actions'
planned by December-31,'1990.
The results of this review and the-
- action plan will be submitted in;a supplement to this response expected to be issued by January ~30,'1991.
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Independent Technical Adequacy Review of the TRIP Procedures, Unresolved Item 90-80-01, Section 4.0 L
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Item 1
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The inspection team identified that.when transitioning to the contingency partion of the PSTG, the PSTG. refers to specific procedure-numbers, such as the T-100 series, rather than the individual'PSTG contingencies.
desconse The PSTG has been revised to reference contingency numbers rather than-TRIP procedure numbers (ST).
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Item 2 The inspectors identified a TRIP procedure deviation from the.PSTG on entering T-100 (SCRAM procedure) instead of entry into'the Reactor, Pressure Vessel (RPV) Control procedure, T-101.
This constitutes extra steps which may not be required and has the potential to cause operator error.
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Inspection Report
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Response
We will evaluate whether the operator should enter T-101' (RPV Control).
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instead of T-100 (SCRAM procedure) when directedoto' SCRAM in a TRIPL
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procedure (LT).
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Item 3
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A. deviation between the,PSTG and the TRIP procedures ~was identified.-
The PSTG direction:given
When emergency RPV depressurization is
required, is to: enter T-101;at Step RC-1 and execute:it concurrently.
The ' TRIP procedures? only direct entry into T-ll2,: Emergency-Blowdown.
Procedure T-112 has_ direction to' SCRAM the reactor if'it.has'not
already been SCRAMed, therefore, entry into~ T-101 is redundant.
The
inspection team concluded that-since T-101 gives the operator guidance
to: control level and-power that T-112 does not,.T-101 should be
entered when emergency blowdown is' required.
Response
This conclusion will be reviewed and appropriate-actions planned (LT).
Item _4
There were several examples of incorrect ~information in the PSTG_that.
reflect on system capability.
The-PSTG refers:toEthe steam condensing
mode of RHR, HPCI use for boron injection, LPCI. loops C and D heat
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exchanger capability and' RPV flooding sources, none of whicli. exist in
the plant.
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Response
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The PSTG,has been revised to reference only Limeri.ck Generating
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Station (LGS) systems and not generic systems 1(ST).
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Item 5
.There are several actions contained in the' TRIP procedures which are
not directed by the PSTGs.
In_T-101.(RPV control),-when an'SRV_is
cycling, adequate core. cooling is'not: considered when establishing
suppression pool cooling.
T-ll2 containsEdirection to avoid emergency
depressurization of the reactor vessel below 100Lpsig unless. motor'
,
driven pumps are available.
Technical-Specifications actions are
included in the SP/T portion of T-102.
Response
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We wi'11 evaluate whether to remove suppression poo.1 cooling operation
from T-101 or specify to use an RHR pump'which is not required for
adequate core cooling (LT).
T-ll2 has been revised to remove this
direction (ST).
We will evaluate whether these actions should be
removed from T-102 (LT).
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Pcga 3~of'10
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In p2ction R portL50-352, 353/90-80
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Item 6
A number of transition points were found to be in error in'several
. TRIP procedures.
, Response
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All TRIP' procedure: flowcharts have-been reviewed and revisedTwhere
necessary to ensure the proper step numbers a.t the entry / exit. arrows
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are correct providing proper transition. directions (ST).
Item 7
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Terminology used in certain flowcharts is ambig'uous.
These terms
require concise definitions that are clearly understood by.the:
operators.
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Response
Administrative ~ Procedure A-94, " Preparation of Transient Response
Implementation Plan (TRIP) Procedures," has been revised to define
terms such as " stabilize", " shutdown", and " consider"E(ST). -We are
evaluating if the TRIPS should~give more guidance on-how the operator-
can determine if the reactor is " shutdown" (LT).
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Item 8
The RPV Control procedure, T-101, step RC/P-14,' directed an operator
to hold at this step until " power is below 4%."
The PSTG requires
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that the operator' determine if the reactor.is " shutdown" at this
point.
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Resoonse
T-101 step RC/P-14 has been revised to verify the reactor is
" shutdown" rather than " power...below 4%" (ST).
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Item 9
The-Primary Containment Control procedure,;T-102, steps SP/L-22 and-
SP/T-14, permit depressurization only if boron injection is not
required.
The PSTG requires depressurization regardless of whether
boron injection is-required.
Response
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The wording "UNLESS BORON IS REQUIRED" has been removed from T-102-
(ST).
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Page 4 of 10
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Inapection R; port 50-352,'353,30-80
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Item 10
The Primary Containment. Control procedure, T-102, step SP/L 3 has=a
note which states that at 17.8 feet suppression pool level, the
SPOTMOS temperature 1 indication becomes~ invalid.
The' note does not
direct the operator to use an alternate indication, in this case
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Residual Heat Removal (RHR) pump suction temperature indication with
an RHR pump in service.
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Response.
Note #2 of T-102 has been revised to add use of the RHR suction
temperature indicator with the RHR pump running (ST).
Item 11
The Emergency Blowdown procedure, T-112,-. steps'EB-1, EB-2 and.EB-3,
require the operator to-SCRAR the reactor and enter the SCRAM
procedure, T-100.
This action ~is considered by'the inspection team to-
be a redundant step since all T-112 entry conditions but one, T-102
DW/T, already direct tne reactor to be SCRAMed prior to entering T-
112.-
Response
We are evaluating placing the SCRAM direction in T-102 DW/T and
removing it from the T-112 procedure.(LT).
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Item 12
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T-112 step EB-19 directed securing HPCI on high suppression pool.
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level.
This is considered to be. redundant due to this guidance-
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appearing in T-102,
Response
Step EB-19 of T-ll2 has been deleted (ST).
Item 13-
The' north and south stack process radiation monitor HI-HI' alarm-
setpoints, used as entry conditions into the Radioactivity Release
Centrol procedure, T-104, are conservative with respect to the BNR
Owners Group Emergency Procedure-Guideline-(EOP) entry condition;
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requireraent of " release rate above the offsite release rate which
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requires'an Alert."
The T-104 entry conditions'are satisfactory with
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respect to monitored releases, but do not directly address-the
unmonitored release path scenario.
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Page-5 of 10-
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. Inspection Report 50-352,353/90-80
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Response
T-104 has been revis ~ to.show an entry:from EP-101E(ST).- EP-101 has
'been revised to give
ection to enter T-104 on appropriste
radiological. conditions ;ST). 'The.PSTG has been' revised to
incorporate the above changos'(ST).
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Control Room and Plant Walkdowns, Sections 5.0.and'10.0-
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Item 1
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Based on walkdowns performed during the Emergency. Operating Procedure.
(EOP) Inspecti~on,'the glare from the plexiglass covering'the
flowcharts in the Main Control Room'(MCR)'is excessive.- The glare.
makes it difficult to use the procedures.
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Response
Actions are being planned to. reduce the glare on the' plexiglass-(L'T).
Item 2
Non-licensed operators (NLOs) occasionally.had difficulty in locating
infrequently operated valves during the walkdown of the-T-200' series
procedures.
Response
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The T-200 series procedures will be evaluated to determine why
operators are having difficulties.in locating valves-and appropriate
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actions will be taken to resolve this problem (LT).
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Simulator, Section 6.0
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Item 1
One of the comments noted during the plant walkdown was that-the
curves in the Safety Parameter Display System (SPDS)Lin the plant do
not agree with the curves in the TRIP procedures.- The SPDS was not
used by operators in the simulator because it is not yet functional lin
the simulator.
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Response
The SPDS curves are being revised to agree with those in the TRIP-
procedures (LT).
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Item _2
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The current location of the SPDS monitors is not. conducive for use by.
the shift supervisor while using the TRIP-procedures..The'SPDS'
monitors'a're located on the shift supervisors desk and.the reactor
operators computer desk.
The TRIP procedures are used byfthe shift
supervisor on the back of the reactor operators. computer. desk.
Neither monitor is visible toLthe. shift-supervisor.
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Response
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The need for relocating the SPDS ter,minals in the MCR so a person
using the TRIPS can read the terminals is being evaluated and
appropriate actions will be determined (LT).-
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Human Factors Review of the EOPs, Unresolved. Item 90-80-02,'
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Section 7.0
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Item 1-
Two principal human factors concerns about.the TRIP flowcharts were
identified: size and complexity.
T-10l=(RPV Control) and T-102-
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(Primary Containment Control) are inconvenient to use because of their
dimensions.
The size of the flowcharts is'related.to the wording of
the step instructions which are frequently long and complex.
Response
Actions are being planned to reduce the size, words, and steps of
flowcharts (LT).
Additionally, specific human factors-findings
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itemized in Attachment C will be addressed by an encompassing' human'
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factors review (LT).
Walkdown Comments, Attachment B
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Item 1
Many of the T-200 series procedures contain sets of steps which-
install jumpers or lift-leads.
However,.the purpose for performing
each step'is not always obvious.
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Insp3ction Report 50-352, 353/90-80
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Response
A review will be performed to determine whether$ descriptive text for
each' major set.ofejumper/ lifted lead steps should be added to the'
T-200 series-. procedures (LT).
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Item 2
Inspectorsnotedthatsomeoftheareamapsandsignsformerly-$ocated'
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at the tops of stairwells and entrances.to areas have fallen-down,-
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This makes it more difficult fort operators'to; locate:
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are missing. ~
- inf requently operated: components;which are required to; be operated. ini
the T-200 series procedures.
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Response
A plan will be developed.to ensure all. area maps in the Reactor;
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Enclosure are in place or to'incorp6: ate. maps.into appropriate. TRIP!
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procedures (LT).
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Item 3
Step RC/P-8 of T-101 has the operator open the-Main Steam Isolation-
Valves.(MSIVs) to provide a heat sink, using procedure T-221 if
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necessary. ' T-101 did not " Restore Instrument Air" after:a LOCA;-signal
per procedure SE-10, nor.did T-221 restore instrument air to the
outboard MSIVs.
Without' instrument air, the Outboard MSIVs could not
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be opened.
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Response
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We added the proper steps to T-221 prior tolthe inspection team-
departing the site (ST).
Additionally, we will review whether.T-101-
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also requires a' revision for this concern (LT).
Item 4
The T-102 related curves in the SPDS did not match the current
revision of the BWR Owners Group EOPs.
SPDS does caution the
operators that the curves currently in SPDS are not valid for use-with'
the TRIP procedures.
Response
Revision to the SPDS curves is ongoing and is expected to be completed
by October 31, 1990..
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Item 5
Curve PC/P-3-(Primary. Containment Pressure, Limit) of T-102 asks for'_
Drywell Pressure on. recorder PR57 *01 to calculate containment 11evel.
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The recorder is labeled "Pri Cont Atm" versus."Drywell Pressure".
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Response
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The' TRIP flowchart'was corrected'to agreeLwith the recorder (ST).
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Item 6
In. step RF-19 of T-116, "RPV Flooding," thefoperator is directed-to
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check for a 69 psid pressure 1 difference'between the reactor pressure
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vessel and the suppression pool ~.- The RPV pressure: Instrument has'20
psig scale increments and the1SP instrument has 5 psig' scale
increments.
A 69 psid would be difficult'to read t
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Response
The 69 psid has been changed to.70 psid (ST).
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Item 7
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The borax and boric acid stored in the locker near the SLC tank would
be of little-use for filling the CRD pump suction strainer body, as'it
would need to be transported down three' floors and from the. reactor
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enclosure building to the turbine. building.
The locker contains no
thermometer as specified in the procedure..
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Response
A thermometer was added~to the cabinet prior to the: inspection team:
leaving the site.. _The T-211 procedure, "CRD SystemLBoric_ Acid-Sodium
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Pentaborate Injection," has since been cancelled as recommended by-the
inspection team since this procedu'e'is not feasible to. implement and
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more desirable methods are available.(ST).
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Item 8
The handswitch for SV-57-201 also controls SV-57-239, but is not
labeled as such on the control board.
Response
A review of the
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.ontrol Room panel labels will be conducted and.
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appropriate corre
ve actions planned (LT).
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Inspection Report 50-352, 353/00-801
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Human Factors Examples, Attachment C.
Item:1
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Administrative Procedure A-94,1 " TRIP Writer's Guide," provides no.
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guidance for,the writing:of logic statements.,
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Response
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Guidance will be included in~A-94 for.writingLlogic statementsR(LT).=
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Item 2
A-94 does not define a very effective way.of1using color'in_the;
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flowcharts.
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Response
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Guidance will be incl'ded in A-94 on effective use of color in the
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flowcharts (LT).
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Item 3
A-94 does not fully state the cc ventions for< presenting referencing
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instractions (i.e., instructions to execute another' procedure-
concurrently) 'and branching instructions
(l'.'e.,; instructions to leave
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the present procedure or. branch and go to another: procedure).
In:the-
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flowcharts, references to T-200 procedures are put inLcommand boxes.-
References to T-100 procedures are putLin special symbols unless the
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reference is conditional, in which case it appears-in the recheck' step
command symbol.
These practices were. found to bei used 'consiste'ntly,
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but they are not mentioned in A-94.
References to non-TRIP; procedures
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are not treated as consistently. 'Sometimeslthey cre in'the commandL
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box and sometimes in the reference symbol.
Examples of this.
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incennistency are given in the findings.related to the TRIP
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procedures.
Response
Writer's guidance will be provided to ensure that consistency is
maintained (LT).
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Item 4
A-94 specifies that flow lines are to be darker than the flowchart
symbols.
The difference in line intensity'is substantial.
The
guidance is inconsistent with the recommended practice (as indicated
in NUREG/CR-5228).
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Response
A-94 and the TRIP procedures will be reviewed with the carrent
direction provided in NUREG/CR-5228 and a tesolution will be
determined for the difference identified (LT).
Item 5
A-44 does not provide guidance on the method of verification, i
e.,
it
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does nut say what will be done to verify a procedure or procedure
revision. A-94 also provides no guidance on how problems identified
during this verification will be resolved.
Response
Additional guidance will be included in A-94 on methods of
verification and validation (LT).
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Items 6 and 7
A-94 does not provide guidelines for determining when verification.is
required and.when validation is requ2 red.
These decisions are left to
ths discretion of the procedure writer who makes recommendations to
)
the Plant Operations Review Committee (PORC).
Additionally, A-94 does
not make it completely clear that verification and validation apply to
satellite procedures (T-200 series) as well as to the flowcharts.
Of
particular concern is the need to make sure that satellite procedures
are walktd down in sufficient detail to make sure that they are
accurate, feasible, and appropriate for the emergency situations that
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the in plant components involved can be readily located; and that the
tools, materials, and equipment needed to perform the tasks are
available.
Response
Actions will be planned to ensure that all T-200 series and satellite
procedures receive verification and validation (LT).
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A root cayse investigation of the noted EOP/ TRIP findings is not
expecte,
o yield significant or opecific corrective actions for the
process.
Therefore, we do not plan to conduct-,ach an investigation.
The cover letter that transmitted the inspection report also requested
that we review these findings to determine if they af'fect the Peach
Bottom Atomic Power Station (PBAPS) TRIP procedures.
These items were
discussed with Operations Support personnel at PBAPS and they agreed
to perform the review.
Additionally, these findings will be
incorporated into the Nuclear Group Administrative Procedure which is
,
being developed to provide a 5onmon procedure for the TLIP procedure
develepment process and wr3cers guide for both LGS and PBAPS.
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