IR 05000282/1981005
| ML19347F908 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/28/1981 |
| From: | Burgess B, Feierabend C, Little W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19347F906 | List: |
| References | |
| 50-282-81-05, 50-282-81-5, 50-306-81-05, 50-306-81-5, NUDOCS 8105260589 | |
| Download: ML19347F908 (10) | |
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U.S. NUCLEAR REGUIATORY COMMISSION
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OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report Nos: 50-282/81-05; 50-306/81-05
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Docket Nos: 50-782; 50-306 License Nos: DPR-42; DPR-60 Licensee: Northern States Power Company 414 Nicollet Mall Minneapolis, MN 55401 Facility Name: Prairie Island Nuclear Generating Plant
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Inspection At: Prairie Island Site, Red Wing, MN 55066 Inspection Conducted: March 1 - April 9,1981 Inspectors: [-[
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C. D. Fe abcnd
B. L. Burgess O/
Approved By:
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W. S. L le, Chief Y
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Reactor Project Section 2C
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Inspection Summarv i
l Inspection on March 1 - April 9,1981 (Report Nos. 50-282/81-05; 50-306/81-05)
l Areas Inspected: Routine resident inspection of plant operation, maintenance, surveillance, security, radiation protection, refueling activities, spent fuel
. pool activities, followup of licensee events, and followup of headquarters requests. The inspection involved a total of 337 inspector hours onsite by 2 NRC inspectors including 63 inspector hours onsite during off-shif ts.
Results: No items of noncompliance were identified.
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i DETAILS'
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1.
Personnel Contacted
- F. Tierney, Plant Manager J. Brokaw, Plant Superintendent,-Operations and Maintenance,
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- E. Watzl, Plant Superintendent, Pirnt Engineering and Radiation Protection
- A. Hunstad, Staff Engineer
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- R. Lindsey, Superintendent, Operations J. Nelson, Superintendent, Maintenance
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J. Hoffman, Superintendent, Technical Engineering D.- Mendele, Superintendent, Operations Engineering D. Schuelke, Superintendent, Radiation Protection
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R. Stenroos, Assistant Radiation Protection
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A. Smith, Senior Scheduling Engineer M. Klee, Superintendent, Nuclear Engineering S. Northard, Engineer D. Haugland, Engineer G. Lenertz, Engineer K. Beadell, Engineer B. Stephens, Engineer-G. Miller, Engineer R. Flack, Shift Supeevisor D. Cragoe, Shift Supervisor
G. Edon, Shift Supervisor i
P. Ryan, Shift Supervisor M. Balk, Saift Supervisor T. Goetsch, Shift Supervisor y
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D. Walker, Shift Supervisor P. Valtakis, Shift Supervisor
- Denotes those present at the exit interview.
2.
Operational Safety Verification a.
General Unit 1 operated routinely throughout the month. Unit 2 refueling outage continued. The unit was restarted and was back on line on April 9,1981.
K. S. Kim, Office of Regulation Research was a site visitor on April 7, 1981. Visit was related to a contract research proga m, b.
Control Room Observations The inspector observed control room operations, reviewed applicable logs, conducted discussions with control room operators and observed shift turnovers. The inspector verified the operability of selected emergency systems, reviewed equipment control records, and verified proper return to service of affected components. The inspector audited the jumpet/ bypass log to confirm system operability.
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c.
Tours Tours of the auxiliary, turbine and containment buildings, and ex-ternal areas were conducted to observe plant equipment conditions, including potential fire hazards, and to verify that maintenance requests had been initiated for equipment in need of maintenance.
By observation and direct interview, the inspectors verified that security procedures were being implemented in accordance with the plant security plan.
The inspectors conducted numerous tours of Unit 2' containment and auxiliary building areas throughout the refueling outage, monitoring activities in progress for adherence to radiation protection controls,_
use of hot work permits and housekeeping / cleanliness conditions.
Housekeeping conditions cn1 the-Unit 2 portion of the auxiliary building reflected the quantity of work in progress at times, but was generally satisfactory.
d.
Operability Verification The inspestors verified operability of the RHR and containment spray systems for Unit I by verifying correct valve positions in the spec-ified flow path and by verifying that the associated power supply breakers and instruments were correctly aligned.
The inspectors performed visual-inspection of the SI, RHR and reactor coolant system valves and instruments inside Unit 2 containment prior to completion of the refueling outage.
3.
Maintenance a.
Review of Work Request (WR's) and Work Request Authorization CRRA's)
i The inspector selected and reviewed several WR's and WRA's to deter-mine the status of safety rel_ted systems, to verify that proper priorities were given and to verify that design changes were initiated where appropriate.
(1) DC80Y127 - Safety Injection Pipe Reroute. WRA's reviewed included E0480-SI-Q through E0506-SI-Q controlling the electrical hookup of reactor vessel injection and hot leg injection containment isolation valves.
(2) DC80Y116 - Unit 2 Containment Electrical Penetration Installation.
WRA's 1433-EE-Q and 1434-EE-Q were reviewed involving local leak-j rate testing of the recently installed containment electrical
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(3) WR's reviewed and not related to design changes were E1664-WL and E1665-WL. The WR's involved the installation of new con-tainment sump "C" level alarm switches.
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Observations (1) Design Changes The' inspectors periodically observed fitup welding for DC80Y116 and electrical hookup and cable pulling for DC80Y127.
(Paragraphs 3.a.1 and 3.a.2)
The inspector also observed local leak rate testing of electrical penetrations A-10 and D-11. Measured leak rates for both penetrations were satisfactory.
The inspector observed installation and portions of the con-nection for containment level alarms. These level alarms will give wide range level indication following a design basis loss of coolant accident. The inspectors also observed the instal-lation of new level alarm switches in reactor vessel sump
"C".
The switches provide sump pump start and stop control and alarm annunciation in the control room.
(2) Repairs to Safety Injection Pumps The inspector observed licensee and vendor representatives per-forming repairs to the SI pumps and witnessed operability. test-ing after reassembly was complete. Although actual damage to the pumps was minimal, considerable time and effort was expended in disassembly, inspection and reassembly of the pumps. Repairs-included straightening of the pump shaft, some dressing of the casing and replacement of seals. The licensee's staff and Oper-
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ations Committee reviewed and evaluated the method of straight-ening the shaft.
Operability tests demonstrated that the repairs were satis factory.
4. Surveillance The inspectors witnessed portions of surveillance testing of safety re-lated systems a:.d components Witnessing included verifying that the tests were scheduled and performed within Technical Specification re-quirements, observing that procedures were being followed, that LCO's were not violated and that system restorat'.on was completed.
a.
SP-1003 Unit 1 Analog Protection and Safeguards Channel Test.
Test was satis factory.
b.
SP-1022 Boric Acid Tank Level Test, Units 1 and 2 Test was satisfactory.
c.
SP-2083 Unit 2 Response to the Safeguards Signal Test The inspector completed a technical review of the pro-cedure and verified that the test was consistant with regulatory requirements, licensee commitments and admin-istrative controls.
In the review of the test the inspec-tor identified valves in the accumulator injection and-4-
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D containment spray systems which receive'an Engineered-Safety Features Actuation Signal (ESFAS) but are not checked for receiving the signal during the test. These valves are normally locked open valves and are not requir-ed to reposition on an ESF actuation The licensee is re-
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viewing the surveillance to determine if these signals should be checked.
The inspector observed the test and verified that minimum crew requirements were met, test prerequisites were com-pleted, special test equipment was in service, the requir-ed data was recorded for final review and analysis, and
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the test results were adequate. The licensee completed an equipment check after ESEAS reset to satisfy the re-quirements of IE Bulletin No. 80-06.
During t.e test the #22 safety injection pump suction re-lief valve lif ted while the operator was in the pump room.
The pump operator reported the relief valve lifting to control and was then checked by Health Physics Technicians for contamination. No contamination was detected.
The cause for the relief valve lifting was found to be that the test line isolation valves were shut.
The licensee disassembled both SI pumps to determine the extent of damage to the pumps. Damage was not severe but did require repairs. (Paragraph 3.b.2 above)
d.
SP-2088 Safety Injection Pumps Test The inspector observed performance of the operability test performed on both SI pumps to demonstrate operability after repairs. The No. 21 SI pump discharge seal was leaking during the initial test. After a minor adjustment the seal was satisfactory. Retesting was satisfactory.
e.
SP-2102 Turbine Driven Auxiliary Feedwater Pump Test The inspector observed testing of the No. 22 AFW pump being tested following svstem modification to make the AFW system independent of AC power.
Initial tests were not satisfactory as the pump tripped on overspeed be-
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cause the steam supply valve opened too fast. Subsequent
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testing, with a restricting valve installed at the bleed port of the air solenoid valve provided acceptable results.
f.
SP-1077 Shield Building DOP Filter Test The inspector observed DOP testing of #22 shielding build-ing ventilation filter after replacement of the charcoal filters.
Test was satis factory.
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5. Operating Events Damage to Safety Injection (SI) Pumps a.
The inspectors investigated the damage to the Unit 2 SI Pumps 'during the testing on March 29,1981 (Paragraph 4.c) to determine the cause and to determine whether any license violations were committed.
(1)
Background The integrated test of response to safeguards systems, SP-2082, is the single most elaborate test performed annually. The test is performed with the reactor in cold shutdown, and has been performed sucessfully during previous refueling outages without incident. Preparations for the test include performance of por-tions of 19 system checklists (as required) in addition to the checklist for the test itself, which addresses all components that receive initiation signals and all controls and/or compo-nents that must be changed from their normal positions prior to the test to prevent unwanted system perturbations.
Just previous to preparing for this test, the licensee had per-formed the Containment Integrated Leak Rate Test (CILRT) which required tagging all containment isolation valves closed.
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covery from the CILRT provides for removal of the test control tags, but does not reposition any valves unless directed by the Shif t Supervisor (SS). Motor operated valves MV32204 and MV32205, SI Test Line to RRST Isolation valves are tagged " closed" for the CILRT. These valves are otherwise normally open. The test line is a portion of the accumulator test piping, and served the addi-tional function of providing a minimum flow path for the SI pumps.
The control switches for MV32204 and MV32205 are physically lo-cated on the accumulator panel of the control board. There is no flow indication on the test line locally or in the control room.
(2) Pump Operation Pump startup appeared normal with no indication of a problem to the operator in the pump areas or in the control room. Discharge pressures were normal. The pumps were operating about 30 minutes when a suction relief valve lifted spraying the room and operator.
The operator called control and the pumps were shut down.
(3) Procedures Review of the procedures used du-ing the test verified that the surveillance procedures, SP-2083, had been followed and that the checklists specified had been reviewed by the SS prior to shift turnover. The integrated operations checklist C1.1.18-2 for Unit 2 does inclode verification that the control switch status is "Open Neutral", but the page was initialed as acceptable for the test although the step had not been completed. The control-6-
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switches are listed on the procedure in sequence, as they are
positioned on the board, above the accumulator isolation valves.
Review of the SP-2083, pretest valve checklist found that the pump discharge valves, 2SI-13-1 and 2SI-13-2 and the.SI pump boric acid supply isolation valves were closed for the test (to prevent unwanted perturbations). The test procedure did not address MV32204 and MV32205, apparently depending on the systems checklists to assure that they were open.
(4) Cause of the Event The inspector considers that the principle cause of the event was inadequate procedures to assure that the SI pumps always have a minimum flow path whenever the pumps are started. The inspector discussed the occurrence, including his assesment of cause and contributing causes during the exit interview.
b Turbine Driven AFW Pump Inoperable On April 7,1981 an operator attempted to start the No. 22 AFW pump
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to feed the steam generators. The pump did not respond. The pump was declared inoperable for approximately one hour and twenty minutes while investigating the cause and testing.
Investigation determined that the restricting valve installed on the solenoid bleed port was sufficiently closed to inhibit valve operation. Final corrective action was completed on April 8,1981 by installing a fixed orifice in the solenoid bleed port and retesting to demonstrate operability.
The licensee will report the event in accordance with Technical Specification requirements.
l 6. Licensee Event Report Followup l
Through direct observations, discussions with licensee personnel, and l
review of records, the following event reports were reviewed to determine
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that reportability requirements were fulfilled, immediate corrective action was accomplished, and corrective action to prevent recurrence had been accomplished in accordance with Technical Specifications. (Closed)
P-RO-81-02 Tube Degradation in Steam Generators The inspectors observed eddy current inspection of steam generator tubes in progress and monitored results of the j
inspections. The inspector confirmed that the licensee expanded the scope of the inspection in accordance with Technical Specification requirements and that the results of the inspections were promptly communicated to NRR.
The licensee's report describes the extent of degradation identified in each steam generator.
As part of the corrective actions for preventing recur-rence the licensee has revised the distribution of the l-7-l
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'feedwater to balance the flow between thelho't leg and!.
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cold leg areas and will continue to inspect.the affected tubes during subsequent. inspections.
7. IE Information Notices ~
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1E Informat?on Notice No 81-04' -- Cracking in' Main. Steam Lines The ' licensee perforned a visual and dye penetrant examination of the.
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internal surface of one. of the "T" fittings, similar to that described in the.information notice. The examination did not identify any ' in-dication of cracking.
(Closed)
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i 8. Procedures.
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Response to Anticipated Transients TheinspectorverifigjthattheproceduresreviewedduringLa previous inspection -. had been approved and implemented.
b.
SP-1070 (2070) Rev.8 - Reactor Coolant SystemiIntegrity Test -
The procedure-was reviewed and approved in'accordance with the lic-ensee's administrative control procedures'and was reviewed by the Operations Committee on February 5, 1981.
The inspector reviewed the procedure and confirmed that the procedure will provide inspections
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for leakage and wi11' measure seat leakage from each of the check i
valves which isolate the reactor coolant system from the residual'
heat removal and safety injection systems.
9. Refueling Activities
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i The inspector verified that, prior to handling of the fuel in the core, I
surveillance testing and preventive maintenance were' conducted as required by Technical Specifications and the licensee's procedures. Refueling re-I lated surveillance procedures observed included: SP-1115 - Spent Fuel Pit i
Ventilation Testing: SP-1051B - Refueling Interlock Test (Refueling Opera-tion) and SP-1051C - Refueling Interlock Test (Refueling Cavity Filled).
Maintenance procedures observed prior to fuel movement included PM-3160-6
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- Manipulator Crane; PM-3160-11 - 21 Reactor Building Crane Electrical Inspection and PM-3160-1 - 21 Reactor Building Crane Mechanical Inspection.
During the fuel movement the inspector observed 3 shifts of fuel handling operations and verified that containmant integrity was maintained, that shift staffing was in accordance with Technical Specifications, that pro-cedures were-in effect to control all objects entering the refueling area, and that good housekeeping was maintained in and around the refueling area.
During initial attempts to remove one of the irradiation access plugs, the plug assembly separated, leaving a portion of the plug in place in l
the reactor vessel. The plug was subsequently removed by the diver, who works on site for maintenance activities. The plug was-replaced with a 1/ IE Inspection Report Nos. 50-282/81-02; 50-306/81-02
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new assembly. The inspectors examined the assembly after removal from the vessel. All component parts were examined and accounted for, with the exception ef portions of the stainless steel pin that locked the two sections together. The two missing pieces were a maximum of t inch in diameter and t inch long. The licensee evaluated the items and entered them in the " Missing Items Log" for the Unit 2 reactor coolant system.
10. Training a.
Operator Training The inspector monitored training in progresc for a license candidate that was performing a reactor startup under supervision of a Senior Reactor Operator. Performance was satisfactory. Training discussions conducted were appropriate and appeared effective.
b.
Badge Issue Training The inspector attended annual badge issue training conducted by the licensee. The training involved lectures concerning plant layout, radiation protection, and respiratory protection. After the lectures written tests were given, and if passed, badges were issued or up-dated as necessary.
11. Review and Audit The inspector attended Operations Committee meetings as indicated:
March 5,1981, Reviewed status of steam generator tube inspection, a.
established plugging criteria for defective tubes and reviewed elec-trical preventive maintenance procedures.
b.
April 3,1981, Review of repair of SI pumps and review of several operating procedures.
April 7,1981, Review of missing parts of access plug.
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No areas of concern were identified.
12. Exit Interviews The inspectors attended exit interviews conducted by RIII inspectors L. Hueter on March 6, 1981, and by G. Pirtle and T. Madena on March 20, 1981.
The inspectors conducted interim interviews during the inspection period and met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on April 9, 1981.
The inspector discussed the damage to the SI pumps (Paragraph 5.a) and stated that he considered several factors contributed to the cause of the occurrence.
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Schedule of test.
(Usually performed earlier in refueling outage 'when most systems are still in normal lineup.)
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b.
Design and labeling of control panels.
(Switches are mounted on accu-mulator panel and are identified as "SI Test Line.to RWST Isola: ion" valves, not readily associated with minimum flow for the pumps.)
c.
Judgment of acceptability of systems for test initiation.
(Could be affected by identification on check'.*tt as test line isolation, rather than SI pump minimum flow, and could also have been affected by the desire to meet schedules.)
d.
Adequacy of the integrated test procedure which provided thct the pump discharge valves be closed but did not address (directly) that a flow path be assured. This was considered to be the principal.
cause of the occurrence.
The inspector stated that, although plant conditions did not require the SI pumps to be operable at the time of the event, status of ECCS system components is always of concern.
The licensee concurred and stated that the plant staff was investigating all aspects of the event to determine what additional actions may be re-quired to prevent similar occurrences. The licensee stated that the po-tential for this occurrence appears to be present only during tests or following a spurious SI initiation. The licensee stated that the items.
discussed as possible contributing causes would be addressed. The licensee stated that the results of the investigation and any resulting changes to procedures and/or design would be included in scheduled training and/or retraining sessions.
The inspector stated that the actions to prevent similar occurrences would be reviewed during subsequent inspections.
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