IR 05000295/1981014
| ML20030D230 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 08/10/1981 |
| From: | Hayes D, Kohler J, Waters J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20030D227 | List: |
| References | |
| 50-295-81-14, 50-304-81-10, NUDOCS 8108310571 | |
| Download: ML20030D230 (12) | |
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCDIENT
REGION III
Report No.:
50-295/81-14; 50-304/81-10 Docket No.
50-295/304 License No. DPR-39, DPR-48 Licensee:
Commor resith Edison Company P. O. Box 767 Chicago, IL 60690 Facility Name:
Zion Nuclear Power Station, Units 1 & 2 Inspection At:
Zion, IL Inspaction Conducted:
May 30, 1981 through July 31, 1981 I
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Inspectors.
J. E. Kohler
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t J. R. Waters 8 - [ " c? /
Approved By:
. W.
ay s,
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Reactor Projects Section IB
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Inspection Summary Inspection on May 30-July 31, 1981 (Report No. 50-295/81-14; 50-304/81-10)
Areas Inspected: Routine, unannounced resident inspection of licensee action
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on previous inspection items, reactor trips, spent fuel rack installation, 1A charging pump piping leakage, axial power distribution monitoring system, receipt of new fuel, radioactive releases, leorcage into containment sump, emergency preparedness exercises, containment purge valvcs, primary to secondary leakage, operational safety verification, safety related maintenance, safety related surveillance, Licensee Fvent Reports, I.E. Bulletins, and I. E.
Circulars. The inspectic.. involved a total of 487 inspector hours onsite by two NRC inspectors including 55 hours6.365741e-4 days <br />0.0153 hours <br />9.093915e-5 weeks <br />2.09275e-5 months <br /> onsite during off shifts.
Results: No items of noncompliance were identified.
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Persons Contacted
- K. Graesser, Station Superintendent
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Soth, Assistant Station Superintendent-Operations G. Plim1, Assistant Station Superintendent-Administrative and Support Services
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Fuerst, Unit 1 Operating Engineer J. Gilmore, Unit 2 Operating Engineer
- P. Kuhner, Quality Assurance Engineer R. Budowle, Assistant Technical Staff Supervisor
- P. LeBlond, Assistant Technical Staff Supervisor
- A. Miosi, Technical Staff Supervisor B. Schramer, Station Chemist D. Walden, Fuel Handling Foreman A. Ockert, Technical Staff Engineer-Primary Group F. Ost, Health Physica Engineer C. Silich, Technical Stati Engineer-ISI
- R. Cascorano, Technical S',aff Engineer-Radwaste
- M. Krysiak, Quality Control Engineer
- D. McMenamin, Quality Assurance Engineer
- Denotes those present at management exit of July 31, 1981 2.
Licensee Action on Previous Inspection Findings (closed) Unresolved Item (50-295/81-01-1): The licensee has determined from the vendor that the Keane solenoid valve failed due to an internal short circuit. The Keane solenoids do not have a history of such failures and the licensee is continuing its program of replacing the Teledyne sole-noid' with Keane solenoids.
No items of noncompliance were identified.
3.
Summary of Operations Unit 1 Unit 1 operated at power levels up to 100% with no reactortrips or un-scheduled shutdowns.
Unit 2 Unit 2 operated at power levels up to 93%. One reactor trip occurred (See 3.c below). Power level was limited due to isolation of one string of low pressure feedwater heaters because of tube leakage. Significant perturbations in operation which occurred during the inspection interval are described below:
On July 6, 1981, power was reduced to approximately 50% to allow a.
personnel entry inside the missile barrier for the addition of oil to a reactor coolant pump.
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b.
On July 13, 1981 the Unit 2 coastdown to the September 11, 1981 refueling outage began. In this condition where reactor coolant system boron concentration is very low, power level is gradually reduced as required to maintain T average within 4*F of T reference.
c.
On July 29, 1981 Unit 2 tripped from 85% power at 1:06 P.M.
A fault in the 2W main transformer cooling fan apparently caused the 480V supply breaker to bus 233 to trip. Upon loss of this bus, the main feedwater pumps went to idle speed and the pump recirculation valves opened as designed for loss of power, resulting in a loss of feedwater to the steam generators. The reactor trip was apparently caused by low steam generator level coincident with steam flow / feed flow mis-match.
Following recovery from the trip, the reactor was made critical at 5:45 A.M. July 30, 1981. When the turbine was latched steam flow surges caused a steam flow / feed flow mismatch signal. Since the D steam generator was already below the low level alarm point, the re-actor again tripped on mismatch coincident with low level.
The reactor was made critical at 7:15 A.M. and restored to the grid at 12:40 P.M., July 30, 1981.
No items of noncompliance were identified.
4.
High Density Spent Fuel Rack Installation The last of the high density spent fuel racks were installed in the spent fuel pool on June 26, 1981. Approximately two-thirds of the racks have not had the neutron attenuation test performed on them. The testing is scheduled for August 17, 1981 and the neutron attenuation tests should complete the high density spent fuel storage modification.
No items of noncompliance were identified.
5.
Leakage on 1A Charging Pump Lalance Drum Piping On June 29, 1981 the 1A charging pump was declared inoperable due to a crack in the ik inch balance drum piping. This pipe connects the area adjacent to the discharge shaft seal to the area adjacent to the tuction shaft seal. Its function is to reduce pressure on the discharge seal to that at the pump suction. The crack extended almost 1800 aronnd the pipe and was located nex'. to the pipe casing butt weld on the suction end of the pump. With one charging pump inoperable, Unit 1 entered a seven day limiting condit'an for operation as required by Technical Specifica-tions. The repair consisted of replacing a section of pipe approximately one foot long between the pump casing and a flanged joint. Repairs were completed on July 3, 1981.
Although the cracked section of pipe was destroyed during replacement, i
preliminary metallurgical examinations indicated that the crack was caused-3-
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by fatigue due to vibration, aggravated by a stress riser. Vibration measured on the balance drum piping of 1A charging pump was a factor of 10 higher than that measured on the other three charging pumps. After completing the repair a pipe restraint was installed on the expansion loop in the center of the balance drum piping. This reduced the vibration approximately in half. Work is currently underway to install a second pipe restraint in attempt to further reduce the piping vibration.
lA charging pump is currently caution carded to be run or.'" when necessary until pipi g vibrations are improved. The current vibration levels do n
not rendez the pump inoperable.
On July 8, 1981 a 3/4 inch crack was found on the socket weld between the replacement pipe and the flange. Since the pipe extended approximately 1/2 inch into the flange, the licensee installed a number of braces and a strongback in order to hold the joint together in case the weld failed entirely. The pump was thus maintained operab.'e until the 1A diesel generator was returned to cervice the next day. The 1A charging pump was then taken out of service and the crack was repair welded. The li-censee attributes the crack to a defective weld performed during replace-ment of the cracked pipe.
No items of noncompliance were identified.
6.
Axial Power Distribution Monitoring System (APDMS)
As a result of facility licensee amendment 67 and 64, the reactor core peaking factors were revised upward based on improvements made in the computer model of core power distribution. The NRC inspected the licensee's implementation of the new core peaking factors during the review of Unit I start-up testing after the spring 1981 refueling. The increased peaking factor limits permitted the APDMS on both Unit 1 and 2 to be deactivated, and neither Unit 1 nor Unit 2 are peaking factor limited at any time during the present cycle.
No items of noncompliance were identified.
7.
Purging Above Cold Shutdown As referenced in NRC Inspection Report 50-295/81-01; 50-304/81-01, the Zion Station has complied with the NRC interim position on purging. As such, the valve movement has been limited to between 30 to 50 degrees of full open during purging operations. With the valve position limitations, purging has been performed above cold shutdown.
The NRC recently received notification from the Henry Pratt Valve Company that some valves with the position limitation installed may still not be able to close against the dynamic pressure response of a hypothetical design basis accident. The Resident Inspector's office determined through discussions with the licensing project manager that the Zion Station was not affected by the Pratt notification.
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No items of noncompliance were identified.
8.
Receipt of New Fuel On July 15, 1981 the licensee begaa receipt of new fuel for the Unit 2 refueling outage. The inspector observed receipt and storage of two fuel assemblies. The inspection of fuel by quality assurance, technical staff, engineers, and v<ndor representatives was also observed. The in-spector verified compliance with approved fuel receipt procedures. One assembly was marked with a hold tag pending resolution of an ASME num-bering discrepency.
No items of noncompliance were identified.
9.
Radioactive Releases a.
Release of July 14, 1981 On July 14, 1981 at approximately 10:30 A.M.,
contractors began cutting 3/8" sample system piping down stream of valve SS9368D as part of a TMI sample system modification to Unit 1.
This pipe is a sample line from the Unit I letdown demineralizer outlet. When the pipe wall was breached, water began issuing from the cut and the workers waited for the line to stop draining. After about 45 minutes, the water was still issuing from the cut and the control room was notified. An alarm was received on 2RT-PR07B (Unit 2 pipe chase rad monitoi) at about the same time. Personnel who were dispatched from the control room to investigate found that the reach rod to SS9368D had malfunc-tioned. The valve, which had been tagged shut, was partially open.
SS9368D was then shut locally stopping the flow of water. This oc-curred at about 12 o' clock noon.
The total quantity of water released was estimated to be less than 25 gallons with an activity of less than 2 curies. The maximum in-stantaneous release rate was calculated to be 410 uc/sec, which is 0.7% of the Technical Specification limit. No personnel were con-taminated.
No items of noncompliance were identified, b.
Sample System Release At 10:05 P.M. on June 23, 1981, a small unplanned radioactive release from the Unit 2 sample system occurred. The release was terminated at 11:30 when it was dete7 mined that the source of radiation leakage was through an open line in Unit 2 RHR pipe chase. The amount of activity released was 6.1 curies, at a maximum release rate of 4400 u ci/sec. This corresponds to 7.4% of the Technical Specification instantaneous release limit. The NRC was notified at 11 o' clock P.M.
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Further investigation on the part of the station and resident in-rpecto' 's office revealed the following details: The Unit 2 primary reactor coolant sampling system was taken out of service on June 22, 1981 in order to remove check valve 2SS 9369B. The system continued to be out of service on June 23, 1981 until 7:30 P.M. when the oper-ating department required the system to be returned to service so that the daily primary reactor ecolant samples could be taken.
Operating Department checked oy telephone with the maintenance planning engineer responsible for knowing the status of the sample system. He indicated the system could be returned to service because the work had not begun. The system was returned to service. However, the planning engineer was unaware that valve 2SS9369B had been worked on and physically removed leaving an open line and causing the unplanned release upon sample system operation.
The cause of the release was a personnel error on the part of the main-tenance planning engineer. He should have checked with the local job foreman prior to releasing the system for service, but he did not because he was sure the system had not been worked on and still maintained its integrity. The system had integrity up to 2 P.M., or one hour before the end of the work day. He assumed, therefore, that it had not been worked on.
This was an incorrect assumption because the system was worked on at 2:30 P.M.
No procedural violations were discovered by the operating or radiation protection departments. It was determined that by procedure, the main-tenance planning engineer does have the authority to take systems out of service for his foreman. Through communicating with the foreman, the maintenance planning engineer can return systems to service.
The resident inspectors discussed the event with the parties involved.
No changes in the out-of-service procedure are planned.
No items of noncompliance were identified.
10.
Leakage to Unit 2 Containment Sump On July 12, 1981 a significant increase in Unit 2 containment sump pump run time was observed.
Investigation into this phenomenon by the inspector revealed several discrepencies:
a.
It was thought that upon reaching the high level float switch one of two redundant sump pumps was activated with the pump alternating.
However, electrical prints did not reflect this, and pump run time logs showed that only one pump was operating, b.
Log sheets from daily reactor coolant leakage surveillance tests (PT-21) assumed a 50 gpm flow rate foi.ach pump but no basis for this assumption could be found since records indicating the type of pumps installed were not available.
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The licensee was asked to resolve these discrepencies.
During the outage resulting from the Unit 2 trip of July 29, 1981 the licensee entered containment and ascertained the following:
a.
The two pumps did alternate operation off the same float switch.
However, the 2B pump and its run indicator were malfunctioning and not pumping at all. At the high-high level switch, both pumps were supposed to start. Therefore, when the 2B pump was supposed to start but didn't, the level in the sump would continue to increase to the high-high level where the 2A pump would start.
b.
The 2A pump is manufactured by the Flygt Company while the 2B pump is manufactured by Chempump. The flow rate of the 2A was measured
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by two methods--using measured level drop in the sump over run time f
and using sump level indicator change over run time. The two methods yielded flow rates of 46.8 gpm and 35.9 gpm respectively. The former method is considered the more accurate.
c.
The licensee also located steam generator hand hole cover leaks totaling approximately 2-3 gpm which coincides with the currently calculated sump input from PT-21.
The licensee is taking the following corrective actions:
(1) The nonfunctioning Chempump will be replaced during the upcoming refueling outage.
(2) Appropriate drawings are to be modified to reflect the correct controlling circuitry of the two sump pumps.
No items of noncompliance were identified.
11. Emergency Preparedness Exercise The licensee conducted an emergency preparedness drill on July 29, 1981 involving various federal, state and local authorities. The drill sim-ulated a Unit i reactor coolant system leak leading to shutdown. Core damage, a containment pressure excursion and significant radioactive f
release ensued. The licensee used emergency operating procedures to mitigate the consequences of the event. Details of the exercise and evaluations thereof are available in other NRC and Federal Emergency Management Agency reports.
No items of noncompliance were identified.
12.
Unit 1 Primary to Secondary Leakage Inspection Reports 50-295/81-09 and 50-304/81-05 documented primary to secondary leakage in the IB steam generator. The licensee has continued to perform periodic measurement of the leak rate with results as follows:
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DATE LEAK RATE CAL / DAY June 4, 1981 26.1 June 8, 1981 12.8 June 11, 1981 13.3 June 18, 1981 24.3 June 26, 1981 7.4 July 7, 1981 none detectable July 10, 1981 none detectable July 30, 1981 none detectable P.cgarding the last three leak rates, the licensee has been advised by Trojan Nuclear Power Station and Westinghouse that tangential stress cracks in the row I and row 2 U-bends have shown a propensity to vary in size and it is not unusual for the cracks to close completely, i'
noted in Inspection Reports 50-295/81-01 and 50-304/81-01 previous eddy current testing at Zion has shown many indications in the IB steam gen-erator row I and 2 U-bends.
No items of noncompliance were identified.
13.
Operational Safety Verification The inspector observed control room operations, reviewed applicable logs and conducted discussions with control room operators during the months of June and July. The inspector verified the operability of selected
emergency systems, reviewed tagout records and verified proper return to I
service of affected components. Tours of the auxiliary building and
turbine building were conducted to observe plant equipment conditions, including potential fire hazards, fluid leaks, and equipment vibrations and to verify that maintenance requests had been initiated for equipment in need of maintenance.
The inspector by observation and direct interview verified that the physical security plan was being implemented in accor-dance with the station security plan.
The inspector observed plant housekeeping / cleanliness conditions and verified implementation.of radiation protection controls.
During the month of July, the 1A charging pump, IA diesel generator, Unit 1 emergency shutdown panels, and ESF bus 248 room were inspected to verify operability and general external condition. The inspector also witnessed portions of the radioactive vaste system controls associated with radwaste shipments.
These reviews and observations were conducted to verify that facility operations were in conformance with the requirements established under Technical Specifications, 10 CFR, and administrative procedures.
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No items of noncompliance were identified.
14.
Monthly Maintenance Observation Station maintenance activities of safety related systems and components listed below were observed / reviewed to ascertain that they were conducted in accordance with approved procedures, regulatory guides and industry codes or standards and in conformance with Technical Specifications.
The following items were considered during this review: The limiting conditions for operation were met while components or systems were removed from service; approvals were obtained prior to initiating the work; activities were ac-complished using approved procedures and were inspected as applicable; functional testing and/or calibrations were performed prior to returning components or systems to service; quality control records were maintained; activities were accomplished by qualified personnel; parts and materials used were properly certified; radiological controls were implemented; and, fire prevention controls were implemented.
Work requests were reviewed to determine status of outstanding jobs and to assure that priority is assigned to safety related equipment maintenance which may affect system performance.
The following maintenance activities were observed / reviewed:
a.
Repair of 1A diesel generator b.
Repair of 1A charging pump balance drum piping Following completion of maintenance on the 1A diesel generator and 1A charging pumps, the inspector verified that these systems had been returned
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to service properly.
No items of noncompliance were identified.
15.
Monthly Surveillance observation The inspector reviewed Technical Specifications requires surveillance testing on the 1A and IB RHR pumps, lA and IB safety injaction pumps, 1B and 0 Diesel Generators, and batteries 111, 112, and 011, and verified that testing was performed in accordance with adequate procedures, that test instrumentation was calibrated, that limiting conditions for operation were met, that removal and restoration of the affected components were accomplished, that test results conformed with Technical Specifications and procedure requirements and were reviewed by personnel other than the individual directing the test, and that any deficiencies identified during the testing were properly reviewed and resolved by appropriate management personnel.
No items of noncompliance were identified.
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16. Licensee Event Reports Followup Through dircet observations, discussions with licensee personnel, and review of records, the following event reports were reviewed to determine that reportability requirements were fulfilled, immediate corrective action was accomplished, and corrective action to prevent recurrence had been ac-complished in accordance with Technical Specifications:
LER NO.
Ur.it 1 81-02 (Update) Failure of IB MSIV to Close 81-04 (Update) Micro Switch Out of Tolerance
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81-21 Loss of Both Channels of Heat Trace 81-22 Inverter Failure, Reactor Trip and Safety Injection 81-23*
Failure to Report Inoperable Fire Detection Components 81-24 Rad Monitor Found Cecured 81-25 ORT-PR12A & B Found Secured 81-26 ORT-PR12A & B Failure to Install Filters 81-27 ORT-PR18A & B Failure to Install Filters 81-28 Failure of ORE-0014 81-30 Failure of IB DG Control Panel Breaker 81-31 Failure of ORT-PR 25 81-21 Leakage From 1A Charging Pump Piping LER NO.
Unit 2 81-07 Drifting Pressurizer Level Channel 81-08 Inverter Failure 81-09 2D MSlV Drifted Open 81-10 Loop B OPAT and OT&T Channel Erratic 81-11 *
Late Surveillance on OPAT 81-13 2B Steam Generator Non-conservative Drift-10-
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Regarding LER 295/81-25, the licensee is investigating methods of de-energizing radiation monitors locally. This is classified as Open Item 295/81-14-01, 304/81-10-01.
The events concerning LER 50-295/81-21 are discussed in detail in para-graph 5 of this report.
- Items marked with an asterik are classified as licensee identified for which no citation will be issued.
No items of noncompliance were identified.
17.
IE Bulletin Followup For the IE Bulletins listed below the inspector verified that the written response was within the time period stated in the bulletin, that the written response included the information required to be reported, that the written response included adequate corrective action commitments based on information presentation in the bulletin and the licensee's response, that licensee management forwarded copies of the written response to the appropriate onsite management representatives, that information discussed in the li-censee's written response was accurate, and that corrective action taken by the licensee was as described in the written response.
IEB NO.
TITLE 80-24 Leakage luto Containment 81-03 Flow Blockage Due to Asiatic Clams No items of noncompliance were identified.
18.
IE Circular Followup For the IE Circulars liated below, the inspector verified that the Circular was received by the licensee management, that a review for applicability
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was performed, and that if the circular was applicable to the facility, l
appropriate corrective actions were taken or were scheduled to be taken.
IEC NO.
TITLE 80-22 Confirmation of Employee Qualificatione 19.
Meetings, Offsite Functions The inspectors attended the following offsite functions during the inspec-l tion period:
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i J. E. Kohler July 1-2, 1981 Braidwood Nuclear Power Station, - Training Exercise Braidwood, Illinois i
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July 8-10, 1981 IE:HQ, NRR Meeting on Technical Specification Induced Reactor Challenges Bethesda, Md.
J. R. Waters July 30, 1981 FEMA Emergency Preparedness Drill Evaluation Zion Holiday Inn, Zion, IL.
20.
Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance or deviations. One unresolved item (Paragraph 16) was disclosed during this inspection.
21.
Exit Interview The inspector met with licensee representatives (denoted in Paragraph 1)
throughout the month and at the conclusion of the inspection on July 31, 1981 and summarized the scope and findings of the inspection activities.
The licensee acknowledged the inspector's comments.
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