ML20236K594
| ML20236K594 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom, 05000000 |
| Issue date: | 07/25/1986 |
| From: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20236K265 | List:
|
| References | |
| FOIA-87-377 NUDOCS 8708070180 | |
| Download: ML20236K594 (10) | |
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NUCLEAR REGULATORY COMMISSION REGION I g
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631 PARK AVENUE O,% ' KING OF PRUSSIA, PENNSYLVANIA 19406 PM Art < )~
s.. . . . *& 25 JUL 1986 MEMORANDUM FOR: C. J. Heltemes, Jr. , Director, ]
Office for Analysis and Evaluation of Operational Data :
FROM: T. E. Murley, Regional Administrator, Region I
SUBJECT:
INPUT TO ABNORMAL OCCURRENCE REPORT TO CONGRESS FOR I SECOND QUARTER CY 1986 {
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As requested in your July 1,1986 memorandum, the Region I staff has reviewed the items proposed as potential Abnormal Occurrences and your request for further information. The following inputs and comments are provided for your use and j consideration:
l t Potential Abnormal Occurrences l 1. Out-of-Sequence Control Rod Withdrawal By Plant Operators l (Peach Bottom Unit 3) l J
Attachment 1 provides a draft input for this event. The event did not result l in a major degradation of essential safety equipment. However, the multiple errors on the part of four licensed individuals may be indicative of a major on-shift management deficiency with potential safety significance.
Region I, therefore, concurs that this event is reportable as an Abnormal l Occurrence.
- 2. Diagnostic Medical Misadministration (Robert Packer Hospital and Guthrie Clinic; Sayre, Pennsylvania)
See Attachment 2. Region I believes that this incident should be reported as an Abnormal Occurrence.
- 3. Willful Non-Reporting of A Medical Misadministration (Mercy Hospital; Wilkes Barre, Pennsylvania)
See Attachment 3. Region I concurs that this incident should be reported as an Abnormal Occurrence.
- 4. Decay Heat Removal Problems At Pressurized Water Reactors Without further information on the San Onofre Unit 2 failure of shutdown cooling event, Region I cannot conclude that an Abnormal Occurrence classi-fication is appropriate for this specific event. The Region would be interested in following the generic implications of such events, especially j the identification of credible accident sequences resulting from the loss o decay heat removal while in cold shutdown.
.,b 8708070100FOIA 8700M PDR PDR GORDONB7~377
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Memo te H'ltenes e 2 I
- 5. Appendix B Material i Region I has no updating material for Appendix B to the Abnormal Occurrence !
Report. Referring specifically to A0 86-7 involving Radiation Technology, Inc., the Region has provided AEOD with updating material for the 1st Quarter report. We do expect additional activity related to this A0 in the near J
future.
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- 6. Ag endix C Items As requested in your July 1,1986 memorandum we have provided summary infor-mation pertaining to the Pilgrim Augmented Inspection Team (All) results, (see Attachment 4). Concerning the question of reporting AIT findings as Appendix C items, we sugges+. that AE00 consider each AIT on its own merits and to make a decicion es to whether it is of interest to Congress. The 2 Filgrim events initially appeared to have significant rafety interest, but I once the post event analyses and test wtre evaluated no significant degrada-tion of safety could be identified. Region I believes that additional criteria should be deve16 ped for deciding whether AIT's are of sufficient interest to be reported a.s Appendix C items. i l
Please contact K. G. Murpby at FTS 463-1210 if further ir,fsrmation is required.
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Thomas E. Murley l Regional Administrator l Attachments: As Stated l
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1 ATTACHMENT 1 OUT-OF-SEQUENCE CONTROL R00 WITHDRAWAL BY PLANT OPERATORS-PEACH BOTTOM UNIT #3
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OATE AND PLACE l On March 18, 1986, during a startup of Peach Bottom Unit 3, a licensed operator j withdrew a control rod in the wrong sequence and continued to withdraw control (
t rods without detecting the error. Additional administrative and plant system l l controls to detect the error and prevent further rod movement were inoperable or )
! were bypassed by other operators. The error was detected by the next operating shift and the unit was shut down, {
f l Peach Bottom Unit 3 is a General Electric (GE) designed boiling water reactor l (BWR) operated by Philadelphia Electric Company (PEco) and located in l York County, Pennsylvania. !
NATURE AND PROBABLE CONSEQUENCES l To limit reactivity additions during startup and low oower operations, BWRs utilize l a variety of procedural controls and monitoring systems. The reactor operator l follows a control rod withdrawal sequence procedure developed by reactor engineers.
l A Rod Worth Minimizer (RWM) computer system monitors this sequence and blocks control rod rrovement upon significant deviation from the prescribed sequence. A Rod Sequence Control System (RSCS) complements and backs up the RWM in restricting control rod movement. A major purpose of these controls is to limit the conse_
quences of a control rod drop event during startup.
On March 17, 1986, a startup was begun on Peach Bottom Unit 3. The Rod Worth ,
Minimizer was bypassed due to a computer hardware fault. As allowed by Technical !
Specifications, a second licensed reactor operator was assignod to monitor another licensed reactor operator as he withdrew control rods in accordance with the sequence prescribed by procedure. At 1:28 am on March 18, 1986, the operator withdrew control rod 10-23 out of sequence instead of rod 02-23. The second operator monitoring the rod withdrawals failed to notice the error. Later, at its prescribed place in the procedure, both operators signed off the withdrawal of control rod 10-23. Shortly afterward, the reactor attained criticality. At 2:30 am, withdrawal of additional control rods in an attempt to increase reactor power was blocked by the Rod Sequence Control System since rod 02-23 was not in its prescribed position. The Shift Superintendent and Shift Supervisor then bypassed the RSCS rod 02-23 full out logic with a keylock switch without verify-ing the rod position and conformance to the rod withdrawal sequence as required by the procedure for bypassing RSCS logic.
Rod withdrawal and startup continued with Rod 02-23 fully inserted instead of being fully withdrawn as required.
After 7:00 am, the oncoming shift requested that the RWM be returned to service.
This was accomplished at 7:38 am; the operators noted an insert error for rod 02-23. The rod was confirmed to be out of position for the sequence. The shift supervisor returned the RSCS bypass for control rod 02-23 to normal. Two control rods were inserted and then the reactor was manually scrammed from approximately 3% power at 8:55 am. The NRC Senior Resident Inspector and Duty Officer were notified of the scram and the out-of-sequence rod shortly afterward.
ATTACHMENT 1 2 PECo presented an analysis of potential consequences of a rod drop event for various rod pairs for the March 18 event. The peak enthalpy deposition in a fuel pin, had a rod drop occurred with rod 02-23 inserted, for the worst case was calculated to be 118 cal /gm. This is less than the peak enthalpy deposition of ,
215 cal /gm from the reload analysis for the current fuel cycle and the 280 cal /gm !
design criterion.
An NRC special inspection was conducted March 18-21, 1986. j CAUSF OR CAUSES The out-of-sequence control rod withdrawal resulted from numerous personnel errors by four licensed operators. One licensed reactor operator withdrew the wrong l control rod from the core. The RWM, designed to detect such an occurrence, was j inoperable. A second licensed operator was assigned to independently verify the l correct rod withdrawal sequence as required by Peach Bottom Technical Specifica- 1 tions; he did not identify the error. When the point in the sequence to withdraw the rod already incorrectly withdrawn was reached, neither reactor operator identified the previous error. The Shift Supervisor and Shift Superintendent who were overseeing the startup activities failed to note the error. Further, I they bypassed the RSCS without assuring that the bypassed control rod was in its correct position, as required by the procedure for use of the bypass keys. These personnel errors by four licensed individuals showed inattention to detail, failure to adhere to procedural requirements and complacent attitudes, j ACTIONS TAKEN TO PREVENT RE0CCURRENCE Licensee: I The four individuals involved in this event were disciplined. Plant staff man- I agement meetings were held with all operations personnel to discuss the event and !
' their individual responsibilities. Procedural controls were strengthened to, among other things, use best efforts to place the RWM in service, dedicate a I second operator to sequence verification if RWM is bypassed, generate rod position t
maps at specific withdrawal points and compare with prepared rod position maps and require positive rod position verification prior to RSCS bypass.
NRC:
After notification of the out-of-sequence control rod withdrawal by the licensee or. March 18, a special safety inspection into the event was conducted at Peach Bottom Atomic Power Station on March 18-21, 1986. The inspection results were forwarded to the licensee in a letter dated March 25, 1986 (Reference 1).
An enforcement conference was held at NRC Region I on March 27, 1986 between NRC and licensee personnel to discuss the causes for the occurrence of an out-of-l sequence control rod withdrawal and the corrective actions taken and planned.
! A Notice of Violation and Proposed Imposition of Civil Penalty in the amount of l $200,000, dated June 9, 1986, was sent to Philadelphia Electric Company (Refer-l ence 2) describing the violations resulting form numerous personnel errors by l several licensed personnel.
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1 ATTACHMENT 1 3 REFERENCES
! 1. Letter from Richard W. Starostecki, Director, Division of Rector Projects, i
NRC Region I to Mr. S. L. Daltroff, Vice President, Electric Production, Philadelphia Electric Co., Docket No. 50-378, March 25, 1986.
- 2. Letter from Thomas E. Murley, Regional Administrator, NRC Region I, to Mr. S. Daltroff, Vice President, Electric Production, Philadelphia Electric Co., Docket No. 50-278, June 9, 1986.
- 3. Licensee Event Report 3-86-09, Docket No. 50-278. Event Date, March 18, 1986.
Report Date April 16, 1986.
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ATTACHMENT 2 ABNORMAL OCCURRENCE DESCRIPTION i
.l Diagnostic M administration Date and Place: On May 16, 1986, NRC received written notification that on May 7, 1986 an out patient of the Robert Packer Hospital and Guthrie Clinic l in Sayre, Penns91vania, received 10 millicuries of iodine-131 rather than the I prescribed radiopharmaceutical for,a bone scan, technetium-99m. This constituted a diagnostic misadministration.
Nature and Probable Consequences: Approximately two weeks before the scheguled appointment, an out patient was mistakenly scheduled for a whole body iodine-131 scan rather than a whole body bone scan. At the time of scheduling, j a verbal confirmation for an iodine-131 whole body scan was received from the i doctor's office. '
The patient arrived.without a requisition for the study and the technician l administered 10 mi'.licuries of iodine-131 without the consultation with a j radiologist required by department policy. The patient was instructed to return the following day for the imaging procedure. On return to the hospital the following morning, the patient produced an order from her physician requesting that a technetium-99m bone scan be performed. The technician pro-ceeded to perform the wnole body iodine-131 scan and then nce fled the radio-logist of the misadministration.
The licensee informed the NRC the misadministration and the p-obable medical effects were explained to the patient. The patient was give _ugol's Solution and instructed to take six milliliters four times per day fc- four days.
Arrangements were made for her thyroid function to be evalua ed and followed.
Cause or Causes: Failure on the part of a nuclear medicine technologist to adhere to department policy on the prerequisites required for radiopharmaceu-tical administration.
Actions Taken to' Prevent Recurrence:
Licensee: All concer,ned personnel have been retrained on the policy of not administering radioisotopes without a written requisition anc of the require-ment to obtain thi spcific consent of a radiologist for all cases requiring the administration of greater than 300 microcuries of iodine-131.
NRC: The incident is being reviewed by an NRC medical consu' tant. Region I plans to conduct an inspection once this review has been com;1eted.
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ATTACHMENT 3 Abnormal Occurrence Description l l
Willful Non-reporting of a Medical Misadministration l
Date and Place: On May 8, 1985, a patient at Mercy Hospital, Wilkes-Barre, Pennsylvania, received an injection of a radiopharmaceutical which was intended for another patient. This misadministration was not reported to the i NRC within the period specified by 10 CFR 35.43.
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Nature and Probable Consequence: An anonymous allegation was received by i Region I on May 8, 1985. The alleger stated that a misadministration had i occurred that morning at Mercy Hospital when the Chief Nuclear Medicine Technician mistakenly injected the wrong patient with a radiopharmaceutical.
Further, the alleger stated that the misadministration would not be reported to the NRC. The required report of the misadministration was due to the NRC by July 10, 1985.' On July 17, 1985, two Region I inspectors performed a routine unannounced inspection and followup of the allegation at the licensee's facility. During the inspection, the Chief Nuclear Medicine ,
Technician stated that no misadministration had occurred since the one I reported to the NRC in 1984. However, the inspectors noted that records showed one patient had received two radiopharmaceutical injections in a one hour period on May 8, 1985. The Chief Nuclear Medicine Technician stated that this was not because of a misadministration.
On August 7,1985, an investigator from the NRC's Office of Investigations (01) went to Mercy Hospital. During an interview with the Chief Nuclear Medicine Technician, she admitted she had lied to the NRC on July 17, 1985.
The Chief Nuclear Medicine Technician also stated she was told that the l Radiation Safety Officer (RS0) did not want the misadministration reported. l The RSO stated during an interview with the 01 investigator on August 7, 1985, '
that he had informed some of his staff not to report the misadministration.
The consequences of the licensee's actions in this incident are that (1) it decreases the NRC's confidence that this licensee will report incidents as '
required by regulation and (2) it delays implementation of procedures to prevent future misadministration of a similar nature.
Cause or Causes: Deliberate failure of the Radiation Safety Officer (R50) to follow the required procedure for reporting misadministration and instructing !
the hospital staff not to report the misadministration.
Action Taken to Prevent Recurrence - The NRC issued an Order on June 17, 1986, to Mercy Hosiptal requiring the licensee to show cause why the Chief Nuclear Medicine Technician and the RSO should not be prohibited from the perfonnance or supervision of any licensed activities. The RSO is also involved in NRC licensed activities at Valley Radiology Associates, Inc. and a similar Order was issued to this licensee. Both licensees requested an extention until July 28, 1986 to respond to the Orders.
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T ATTACHMENT 4 Pilgrim Augmented Inspection Team
, The Pilgrim Nuclear Power' Plant, operated by Boston Edison Company, utilizes a General Electric desigr.ed boiling water reactor. The plant is located in Plymouth County, Massachusetts.
'On April 4 and 12, 1986, the Pilgrim reactor scrammed from low power during routine reactor shutdownr. Both scrams were caused by unexpected group I primary containment isolations. In both cases the isolation signal was
'promptly reset, but the four outboard main steam isolation valves (MSIVs)
' rould not be prompth reopened. As a result, the main condenser wts not available as a heat sink during a portion of each event and the High Pressure
,\ Coolant Injectiol fi CI) system was operated in the test mode to control most of the subsequeni reactor cooldown. The shutdown on April lith was initiated
! -) \ ,' because the Residur.1 Heat Removal (RHR) system had been pressurized by leakage of reactor coolant past a check valve and two closed motor operated injection valves in the "B" RHR loop. An Unusual Event was declared because of the RHR valve leakage.
q Following the second scram, a Confirmatory Action Letter (CALj was issued to the licensee on April 12,.1986, which required that all affected equipment be maintained in its ss fcund condition (except as necessary to maintain the plant in a safe shutdown condition) in order to preserve any evidence which would be needed to inspect or reconstruct the events. An Augmented Inspection Team (AIT) was dispatched to the site on April 12, 1986 to review the recent op3 rational events which included 1) the spurious group one primary containment isolations, 2) the failure of the MSIVs to promptly reopen after the isolations, and 3) the recurring pressurization of the RHR system due to valve leakaga.
The AIT findings are docemented in Inspection Report No. 50-293/86-17. The CAL also required that the licensee submit a written evaluation to the NRC of the events noted above prioF to restart and to seek Regional Administration authori-zation for restart . The gJant remained shutdown for the entire second quarter of 1986.
I The actual safety consequences of the events were minimal as the isolation system and MSIV failures %:ere in the conservative direction and there was no indication that the potmtial aisted for a sudden overpressurization and failure of the RHR piping. Dettils of the three operational events are summarized below.
(1) During the reactor shutdowns of April 4 and 12,1986, the two low main steam line pressure alarms and a 3roup I primary containment isolation (resulting in reactor scram) occurred as reactor pressure decreased to approximately 900 mnig fo the shutdown sequer.ce. In both cases, the reactor mode switch had been moved from the "run" to the "startup" position prict to the isolation.
T.*e low main steam line pressure containment isolation function is active in s
the run mode but is bypassed when the mode switch is placed in the startup l mode.
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ATTACHMENT 4 2 During the review of the first isolation, the licensee concluded that all the contacts in the reactor mode switch did not close properly when the switch was transferred from the run to the startup mode during the shutdown. As a retult, the low main steam line pressure containment isolation function was still active when reactor pressure dropped below the trip setpoint (> 880 psig). The licensee implemented administrative controls (removal of mode switch key) to ensure proper contact makeup during transfers and provided training to all control room opera- i tors on mode switch operation prior to the subsequent startup on April 10, 1986.
After the second scram, the licensee performed a comprehensive investigation of the containment isolations. No root cause for the spurious containment isolations was identified; however, the reactor mode switch was still suspect and was eventually replaced. The licensee intends to install additional monitoring equipment and perform additional testing during the subsequent reactor startup to further attempt to identify-the cause of the spurious isolations.
(2) Following the reactor scrams on April 4 and 12, 1986, the containment isola- ,
tions signals were promptly reset; however, in both cases the outboard MSIVS '
could not be reopened for approximately one and a half hours. Reactor pressure at that_ time was approximately 300 psig. During the review of the first event, the licensee concluded that an air leak on the "A" outboard MSIV lowered the air pressure to the four outboard valves and prevented them from fully opening.
The air leak was repaired prior to startup.
Following the second scram, the MSIVs were disassembled and it was discovered that the valve's pilot poppets were either detached from the valve stem or inhibited from fully opening so that the differential pressure across the main poppet prevented the MSIV air operator from opening the valve. ,
A modification implemented during the 1983 refueling outage installed " floating" pilot poppets in the MSIVs. The pilot poppets are attached to the valve stem by threading the poppet onto the pilot poppet nut which is held on the stem by a split retaining ring installed in a stem groove. A set screw was installed i into the poppet to prevent if from unscrewing itself from the pilot poppet nut. l
( However, due to design and installation procedure inadequacies, a lack of posi- 1 l tive set screw engagement allowed rotational / vibrational forces during operation I l to unscrew these assemblies.
The licensee modified the set screw design and installation procedure to ensure positive set screw engagement. All eight MSIVs were repaired using the new design and procedure. '
(3) As reactor pressure was increased during the startup on April 10, 1986, the licensee began receiving "RHR Discharge or Shutdown Cooling Suction High Pressure" alarms. This high pressure alarm is indicative of reactor coolant leakage past the RHR isolation valve and had been frequently received in the past. The alarm response procedure required the operator to: diagnose the source of the leakage and to depressurize the system by opening two motor operated valves that lead to the suppression pool.
Based c., piping temperatures, the operators identified the normally closed "B" RHR injection motor operated valve (MOV) 29B to be leaking. On April lith, the second MOV in the injection line (MOV 288) was closed; however, the RHR high ,
pressure alarm again sounded indicating the leakage continued. As both l J
I AT.TACHMENT 4 3 the M0V's appeared to leak the possibility of violating containment integrity forced the operating staff to declare an Unusual Event and start a controlled shutdown. As noted above, the reactor scrammed on April 12th during the Shutdown. The Unusual Event was terminated when the plant was in cold shutdown on April.12th.
The licensee performed a special water leak rate test and determined that 'the as-found leak rate (at operating reactor pressure) past the "B" RHR injection check valve and the two closed MOVs was approximately 0.5 gpm. The two MOVs also passed a Local Leak Rate Test in accordance with 10CFR 50., Appendix J.
The licensee concluded that the root cause of the RHR high pressure alarms was a relatively small leak past the "B" RHR loop isolation valves in conjunction with apparently leak tight RHR pump discharge check valves. This condition caused a pressure buildup in the intervening pipe segments. There was no indication that the potential for sudden failure of all three isolation valves and resultant sudden overpressurization of the RHR piping existed.
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The licensee disassembled MOV 28B for inspection and repair; however, no problems were noted with the valve's seating surfaces and no improvement with the valve's leak rate were made. Prior to the subsequent reactor startup, the licensee ints 1ds to develop a procedure for quantifying RHR injection valve leakage and controlling RHR system pressure during operation.
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