ML20245H845
| ML20245H845 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 06/26/1989 |
| From: | Delgeorge L COMMONWEALTH EDISON CO. |
| To: | Lieberman J NRC OFFICE OF ENFORCEMENT (OE) |
| References | |
| 0172T, 172T, EA-88-266, NUDOCS 8906300119 | |
| Download: ML20245H845 (7) | |
Text
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Comm:nwrith Edison -
1-72 West Adams Street. Chicago, Illinois
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Y' Address Reply to: Post OTfice Box 7tr
- 1
-' Chicago, Illinois 60690 0767 :.
' June 26,-1989.
Mr.fJames Lieberman, Director
' Office of Enforcement U. S. Nuclear Regulatory Connission j
. Washington', DC 20555
]
Subject:
Byron Station Unit 1 Response to Order Imposing Civ11' Monetary Penalty - Enforcement Action 88-266 l
2 NRC Docket No. 50-454 References-(a):
A'.
B. Davis letter to J. J. O'Connor dated May 24, 1989 Mr. Lieberman ll Reference (a). transmitted the Notice of Violation and proposed Imposition 4 of Civil Penality involving the loss of one train of the residual' heat removal-system'while the water level in the reactor cooling system was being' lowered. A civil penality of fifty thousand do11ars.($50,000) was proposed.
Commonwealth Edison Company's response to th'e specific items in the Notice of Violation are contained ~in Attachment A.
The attachment describes the-steps that'have been taken to enhance the monitoring and level control of the-reactor coolant system (RCS), including elimination of the ambiguity resulting.
from not requiring the use of tygon tubing even though it was required to be installed.' These enhancements and the established program for responding to generic communications show that Commonwealth Edison appreciates the need tot 1)-
implement appropriate procedures for controlling actual plant parameters like RCS levels and (2) ensure that those procedures incorporate industry-wide operating experience.
While Commonwealth Edison believes the Civil Penalty is unnecessary to ensure that critical parameters and systems are controlled in accordance'with appropriate station procedures, we agree that the Byron Station RCS drain.
procedure was inadequate. Therefore, we have elected not to request reconsideration of the civil penality.
Accordingly, enclosed please find a check
'for $50,000 in payment of the fine.
Very tru o
s, 8906300119 890626
' W.
PDR ADOCK 05000454 L. O. De1 George o
PDC Assistant Vice Pres dent Enclosure l
g![
cc A.
B. Davis - Regional Administrator, RIII p
l-L. N. Olshan - Project Manager, NRR 1
Byron Resident Inspector
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ATIAfHMENT A-REPLY TO NOTICE OF VIOLATION
'454/88019-01'
'As'a result of.an inspectionLeonducted during the period September 19 F
through 28,.1988, a violation of NRC requirements.was identified.
In.accordance withLthe " General Statement of Policy and Procedure for NRC Enforcement Actions," 10CFR Part 2, Appendix C 53 Fed. Reg. 40019
'(October 13,1988),.the Nuclear Regulatory Commission proposes to impose a civil. penalty pursuant to Section.234 of the Atomic Energy Act of 1954, as amended (Act), 42 U.S.C.
2282, and 10CFR 2.205.
The particular violation and associated civil penalty are set forth below:
10CFR Part 50, Appendix B, Criterion V, as implemented by' Commonwealth Edison Company,'s Quality Assurance Manual, Quality Requirement 5.0, regatres that activities affecting quality be prescribed by documented procedures of a type
' appropriate to the circumstances.
Contrary to the above, on September 19, 1988, it'was determined'that
- activities affecting quality were not adequately. prescribed by documented procedures of a type: appropriate to the circumstances, as noted by the following examples:
(1)
Byron Operating Procedure' BOP RH-9, Revision 51A, " Pump Down of the Reactor Cavity to the RNST," was inadequate in that it did not specifically require the use of any means.of Reactor Coolant System (RCS) level. Indication during draining of the reactor cavity below the' reactor vessel flange. While the procedure specified that the operator " ENSURE that the tygon hose connection, for RCS level indication, is in place," It did not require that the tygon hose, or any other means of. level indication, be utilized during the. drain down process.
(2)
Byron Operating Procedure BOP RC-4a, Revision 51, " Reactor Coolant l-System Drain," which contains instructions for the installation of the tygon hose level indication system, was inadequate in that it did not provide appropriate guidance for ensuring that the tygon hose was an accurate indication of RCS level, such as verifying j
that the hose was installed vertically, that there were no loop seals, or that the elevation markings were accurate.
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i ATIACIHiRII_.A REPLY TO NOTICE OF VIOLATION 454/88019-01 (Continued) l Resannan 1
Commonwealth Edison admits to the violation of inadequate procedures for draining of the reactor cavity.
Licensed Operators were trained in mid loop operation prior to this event and fully understood the ramifications of RHR pump degradation resulting from air entrainment in the suction line to the pump and the seriousness of losing
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The use of visual observation to monitor reactor vessel level did not anticipate erroneous level indication nor require other means of level indication to be utilized. A licensed-operator was watching RHR pump / motor operation during the draining and took immediate corrective action when RHR pumps suction was lost.
Carrer113m_Ac.tisnE_That Have Rema_Taken_ansLIhe Results Achim3gsl The licensed operator immediately shutdown the RHR pump and flooded the reactor vessel using the refueling water storage tank (RWST).
Reactor vessel level was always maintained above the reactor core with only a minimal change in core temperatures during the event.
Subsequent corrective action included:
A Daily Order was issued prohibiting draining of the refueling cavity below the top of the control rod guide tube assemblies when the upper internals are installed.
l Training sessions were conducted for all operating shifts to discuss the event and the lessons learned.
An operator aid was developed which relates gallons of water removed per foot of level change for both the reactor vessel and the refueling cav3ty.
A root cause investigation was performed with Westinghouse assistance to provide clear understanding of the hydraulic coupling effect with the upper internals installed.
The event has been included in the licensed operator requalification training and non-licensed continuing training programs.
Modifications were installed on Units 1 and 2 to provide indication of reactor vessel level in the control room.
A second level indication will be added during subsequent refueling outages in 1990 on both units.
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ATTACHMEllLA
' REPLY TO NOTICE OF VIOLATION 454/88019-01 l
(Continued)
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Corrective Actions That Have Been Taken and The Results Achieved Continued Subsequent corrective action included:
-BOP RH-9 has.been revised to require two functional. methods of level' indication to be used for any draining operation below the 403' elevation.
In addition, the procedure states visual indication of-reactor vessel level at or below the " Top Hat" area with the upper.
Internals installed is.not reliable or acceptable as one of the two methods for level Indication while draining the reactor vessel. This is due to poor hydraulic coupling between the reactor vessel and the refueling cavity.
BOP RC-4a and BOP RC-4b have been revised to include references to specific procedures, BOP RC-4A1 through BOP RC-4A4, which describe installation of tygon level indication.'.Each of the tygon installation proceduresLrequire that.the tygon tube is' properly hooked up, valved in and thatlno. kinks'or' obstructions exist that could give improper level 1
indication..The tygon hookup -shall be inspected and verified by an SRO licensed' Shift Foreman after installation.
Additionally the procedure requires use of the Chemical and Volume Control-(CV) System when draining below the flange. This results in a lower drain down rate.
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t ATTACHHENI_B a:
REPLY TO NOTICE OF' VIOLATION 454/88019-01 1
Corrective' Actions That Have Been Taken and The Results Achieved i
The following is a summary of the actions in-response to Gener1c' Letter 88-17.
The importance of a loss of RHR during mid-loop operation was stressed after l"
an' event at Diablo' Canyon.' 1011s incident was discussed in NRC Information Notice 88-36 and Generic Letter 88-17.
In response to Generic Letter 88-17,:
Byron Station has completed or will complete a series of procedure revisions and hardware modifications. These actions are divided'into two categories, expeditious actions.and programmed enhancements.
JA.
Expeditious Actions taken include the following:
1.
Training is provided to operators shortly before entering a j
reduced inventory condition. This training is required by
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the' Plant Cooldown and Shutdown General Operating Procedure (BGP 100-5), the Refueling Outage General Operating Procedure (BGP'100-6) and the Reactor Coolant System Drain Operating Procedure (BOP RC-4a/b).
The Diablo Canyon event, related events and lessons learned hcve been incorporated into; the licensed operator Residual. Heat Removal Lesson Plan.
l 2.
Operating procedures have been revised to assure that the containment can be closed before the core could be uncovered by a loss of decay heat removal inc1 dent. The containment closure procedures consider the potential for steam and radioactive material release during such an incxdent.
3.
Procedures AIR _hning revised to require that at least two independent Core Exit Thermocouple (CETs) remain in service whenever the RCS is intentionally drained and the reactor vessel head is in place. ~ The CETs will be monitored periodically and recorded once per shift when the RCS is operated in a reduced inventory condition.
4.
Each unit has a narrow range reactor vessel level monitor that is displayed in the main control room.
Also, a tygon tube is used as a diverse and redundant level indication that can be monitored I
inside contalmnent.
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~,'3 ll lb-i' ATIAGRiENLH REPLY TO NOTICE OF VIOLATION-i a
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I il 454/88019-01 (Continued) 1 t
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i 5.
Operating' Procedures have been revised to caution involved personnel that special attention must be given to all work
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performed during reduced.RCS inventory operation.- In addition, 1
the Work Planning Department has daily meetings with Operating, l
Maintenance, and Technical Staff during. plant. outages. Work that could impact RCS inventory or decay heat removal'would be.
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-discussed at these meetings.
- 6. -
_Two Pumps, including at least one high-pressure injection pump, are available.to add. inventory to the RCS during modes.5 and 6.
In addition, gravity. fill from the Refueling Water Storage Tank provides a third source of inventory addition. These methods of adding RCS inventory are included in operating procedures.
7.
Byron Statiori's design' incorporates loop stop valves which are used to isolate RCS loops ~ for maintenance. Therefore, Eyron does not use nozzle dams..However, procedures have been revised to provide proper instructions should it become necessary to use nozzle dams.
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'8.
When isolating the RCS with loop stop valves, either a hot leg Li l
vent path will be provided or'the RCS will be configured to prevent inventory loss if the reactor vessel pressurizes, s
fB.
~ Er.ngr2emeLKahannementLinclude_the_lalloxingt 1.
'A. modification'is in progress to add a second, independent RCS i
level indication in the control room. Operating procedures are being revised to require at least two independent indications of.
core exit temperature while the head is on top of the reactor vessel (except while the vessel head is being installed or removed). The Decay Heat Removal System is continuously monitored by a diverse set of instrwnents covering both normal and abnormal conditions. These instruments include both visible and audible indication.
2.
Byron has developed procedures and administrative controls to
. cover operation during reduced inventory conditions during both I
normal and abnormal conditions. These procedures will !xa revised, as necesss;fy, after the Westinghouse Owners Group issues their procedurr T this Oplc.
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2.
ATTACHMENT B
+,j REPLY TO NOTICE OF VIOLATION I'
454/88019-01 (Continued) i
~3.
Equipment considerations includes a).
In order to assure availability'of RCS cooling systems,-
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Technical Specifications require that at least one,
'RHR Train is operable.in all operational modes.
b ) '.
Byron' Station is'considering the removal of the RHR auto.
closure-interlock to improve the reliability of the decay' heat removal system.
t c).
LA variety of communication systems-are available for personnel during activities that could affect RCS stability.
i 4.
The Commonwealth Edison Nuclear Engineering Department is performing an analysis to supplement existing information and j
develop a basis for procedures, instrumentation installation and response, and equipment /NSSS interactions and response.
5.
Technica1' Specification changes are being pursued to lower the minimwn RHR flow rate, to remove the surveillance reg'uirement on' the RHR auto closure interlock,.and to permit the operation of one safety injection pump in Modes 5 (Cold Shutdown) and 6 (Refueling).
These actions are believed to be adequate-to address the concerns of the' Generic Letter.and to assure plant safety during mid-loop operations.
'l Date When Full Compliance Will_D_e_ Achieved Items A.3 and all the " Programmed = Enhancements" (B) are still in progress.
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Byron Station has committed to update-the status of these items and provide completion dates to the NRC in September 1989.
j All other corrective actions are complete.
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