ML19309A689
| ML19309A689 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 02/28/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19309A688 | List: |
| References | |
| FOIA-80-186, RTR-NUREG-0578, RTR-NUREG-578 NUDOCS 8004010006 | |
| Download: ML19309A689 (11) | |
Text
.
O EVALUATION OF LICENSEE'S COMPLIANCE WITH CATEGORY "A ' ITEMS OF NRC RECOMMENDATIONS RESULTI)G FROM TMI-2 LESSONS LEAILNED COMMONkT.ALTH EDISON l
ZION NUCLEAR POWER STATION UNITS 1 AND 2 DOCKET NOS. 50-295 AND 50-304 Date:
February 28, 1980 80040in
I.
INTRODUCTION (3), December 3(4)
By gytters dggyd October 19(1):ry1{9yember21(2)and3g8) 14 and 17 1979,, 3,
, and February 22
, 1980, Common-wealth Edison submitted xmitments and documentation of actions taken at Zion Units 1 and 2 Nuclear Plants to implement staff requirements resulting from TMI-2 Lessons Learned. To expedite review of the licen-see's actions, members of the staff visited the licensee's facility on January 21 and 22, 1980. This report is an evaluation of the licensee's ef forts to implement each Category "A" item.which was to have been com-pleted by January 1980.
II.
EVALUATION Each of the Category "A" requirements applicable to PWRs is identified below. The staff's requirements are set forth in reference 9; the acceptance criteria is documented in reference 10.
The numbered desig-nation of each item is consistent with the identifications used in NUREG-0578. Lessons Learned items 2.1.7(a) and 2.1.9 are being reviewed separately and are not discussed in this report.
2.1.1 EMERGENCY POWER SUPPLY Pressurizer Heater The Westinghouse Owner's Group analysis has determined that the minimum requirements to maintain subcooling in a four-loop plant with a pressurizer volume of 1800 cubic feet is 150 kw of heater capacity. Two backup heater groups each rated at 750 kva are energized from emergency 480 volt buses. These buses are energized from separate and independent diesel generators upon loss of offsite power. A control heater group (500 kw) is energized from a third die;el generator. The pressurizer heater groups are connected to the emergency 480 volt buses through safaty grade circuit breakers.
The station emergency and abnormal operating procedures have been revised to remind the operator to check and restore the pressur-izer heaters following a low pressurizer level transient, the only incident which load-shed the pressurizer heaters.
The licensee has satisfied this short term Lessons Learned requirement.
Pressurizer Relief and Block Valves and Pressurizer Level Indications The power-operated relief valves (PORV's) are pneumatically operated from the instrument air system upon actuation of solenoid control valves. The instrument air system is supplied from two motor driven air compressors.
. A connection to the plant service air system serves as a backup air supply for the instrument air system. Each PORV has its own accu-mulator which contains approximately 75 stored operations in the event of loss of instrument air.
The solenoid valves for the two PORV's are energized from 125 volt plant batteries.
The block valves for the PORV's are motor operated valves (MOV) and are energized from the emergency 480V bus which is energized from the diesel generator upon loss of offsite power. This changeover is accomplished automatically. Present Zion operating procedures require the PORV block valves td be in the closed position except when the system pressure is being decreased.
The PORV's and their associated block valves are connected to emergency power through safety grade circuit breakers.
Three pressurizer level transmitter instrument channels indicate level in the control room. These three level instrument channels are inde-pendently powered from vital instrument panels. Each of the three panels is inverter fed from a separate 125V plant battery.
The licensee has satisfied the short term Lessons Learned implementa-tion requirements.
OIE followup is required to ensure that emergency procedures require operators to restore pressurizer heaters following loss of offsite power. This requirement should be reflected in all transients which could result in loss of pressurizer level.
2.1.2 PERFORMANCE TESTING FOR PWR AND BWR RELIEF AND SAFETY VALVES All PWR licensees are required to functionally test reactor coolant system relief and safety valves to demonstrate operability under expected operating conditions. The Category "A" requirement is for the licensee to commit to perform an appropriate test program.
The licensee is participating in the Electric Power Research Insti-tute's (EPRI) program " Performance Verification of PWR Safety /
Relief Valves and Systems."
2.1.3.a DIRECT INDICATION OF POWER-OPERATED RELIIF VALVES AND SAFETY VALVES FOR PWRs NUREG-0578 requires PWR licensees to provide positive position indica-tion for reactor coolant system relief and safety valves. Commonwealth Edison is using the existing stem mounted position indication on the power operated relief valves (PORVs) and has installed an acoustical system designed by Babcock and Wilcox Company on the pressurizer safety valves.
. Zion is presently operating with the PORV block valves in the closed position, isolating the POP.Vs from the pressurizer. They will remain closed until the PORV positive position alarm is installed (the pre-sent alarm associated with the temperature device in the downstream piping). Commonwealth Edison has committed to having the PORV alarm installed no later than April 1, 1980.
The acoustical system to monitor safety valve position meets all short term Lessons Learned requirements.
Schedule for completion of the seismic and environmental qualifications for the acoustical system components is January 1, 1981.
The staff determined during the site visit of January 21 and 22, 1980, that (1) the PORV position indication is powered from a vital instrument bus, and (2) the PORV direct position indication is seismically and environmentally qualified consistent with the component it is, associated with.
Zion is in compliance with short term Lessons Learned requirements. OIE will verify that the PORV block valves are closed and ensure that appro-priate administrative controls are in place to ensure th2y remain closed until the PORV alarm is installed.
2.1.3.b INSTRUMENTATION FOR INADEQUATE CORE COOLING (SUBC00 LING METER)
The licensee is using the plant computer to display the margin of subcooling in 'F on a control board meter. This subcooling temperature is calculated by comparing the saturation temperature obtained from pressure measurements from four narrow range (1750-2500 psig) safety grade pressure channels and one non-safety grade wide-range (0-3000 psig) pressure channel to the average of the ten highest temperature readings from the core exit thermocouples. The licensee has committed to adding a second wide-range pressure channel input to the subcooling meter and upgrade the environmental qualification of the two wide-range pressure channels by January 1, 1981.
The subcooling meter is acceptable in the interim provided that Common-wealth provides redundant qualified wide-range pressure inputs as soon as possible, but no later than January 1, 1981, and that in the interim procedures exist that alert the operator any time environmental condi-tions exist which are more severe than the wide-range pressure transmitters are qualified for.
Zion is in compliance with this requirement.
OIE will verify that backup procedures exist and are acceptable for de:armining degree of subcooling using steam tables. OIE will also verify that emergency procedures alert the operator to environmental conditions that exceed the environmental qualifications of the wide-range pressure transmitters.
. -2.1.4 CONTAINMENT ISOLATION The existing Zion containment isolation design requires that all contain-ment isolation valves (CIVs) in non-essential systems close upon receipt of an autoaatic isolation signal. This meets the Lessons Learned posi-tion on diversity. Diversity is provided (with the exception of main steam isolation valves (MSIV)) by use of a safety injection signal, which has diverse input. Diverse parameters are used to initiate MSIV closure.
The licensee has reverified all essential and non-essential systems and the basis for selection.
For those non-essential systems that are not automatically isolated, a justification has been provided.
Penetrations with normally closed manual isolation valves are locked closed and administratively controlled at any tbne they are open during plant operation. A dedicated person will be assigned to close such valves immediately in the event of an emergency or when the opera-tion is complete.
Modifications have been completed to prevent automatic reopening of any containment isolation valve upon reset of the isolation signal.
The modifications involve replacement of the "two-position" valve con-trol switches with "three-position" valve control switches with seal-in relays. The isolation valves in the gas analyzer system were not modified because the system is inoperable and all isolation valves are secured in the closed position. The licensee has agreed to modify these valves prior to making this system operable. Zion has no valve control switches which allow the reopening of more than one valve at a time.
Zion Units 1 and 2 are in compliance with short term Lessons Learned requirements for containment isolation. OIE will verify that administra-tive controls for manual isolation valves are in place.
2.1.5.a DEDICATED H CONTROL PENETRATIONS The licensing basis for Zion consists of redundant external recombiners.
A preliminary re-design of the system has been completed by the licensee.
Modifications to the existing systems are scheduled for completion prior to January 1, 1981. The licensee is in full compliance with the January 1, 1980 short term Lessons Learned requirements.
2.1.5.c RECOMBINER PROCEDURES The licensee is in full compliance with this position. Recombiner pro-cedures will be required to be updated again, af ter future modifications have been completed.
l l
2.1.6.a INTEGRITY OF SYSTEMS OUTSIDE CONTAINMENT A leakage reduction program has been developed and implemented for Zion.
This program augments the on-going program to minimize leakage from the liquid radwaste system. A summary description of the program is pro-vided in the submittal. -Leak rate measurements have been made and reported.for the gaseous and liquid systems. A list of systems included
.in the program (including CVCS charging and letdown) was provided. The program calls for leak testing most systems once each refueling cycle as well as regular surveillance.
The licensee is in compliance with this item.
OIE will review the adequacy of leak testing procedures to ensure that the leak testing program is implemented.
2.1.6.b DESIGN REVIEW OF PLANT SHIELDING AND ENVIRONMENTAL QUALIFICATIONS The Zion shielding review was conducted by Sargent and Lundy. A formal report was available for review at the plant. The NRC-specified source terms and dose criteria were used. Systems which could contain radio-activity during an accident were considered.
Isolated systems, such as the CVCS and the waste gas treatment system, were excluded. Noble gas leakage from the reactor containment is assumed to be into the auxiliary building and the resulting doses are included. Vital areas identified were the control room, the technical support' centers, sampling area, recombiner control panel and the recombiner pipe connection area; the last three of these require modifications which are required to be complete by January 1, 1981.
A separate study was made nf environmental qualification of safety equipment and required modi.fications are described.
I The licensee is in compliance with this requirement.
2.1.7.b AUXILIARY FEEDWATER FLOW INDICATION TO STEAM GENERATORS The auxiliary feedwater flow for each of the four steam generators is indicated in the control room. This system is energized from the 120V AC instrument distribution cabinet, which is powered from a 7.5 KVA inverter off the station battery. Three narrow range steam generator water level. instrument channels per steam generator which also readout in the control room provide backup to the flow instruments. These 1evel channels are energized from inverter power instrument distribu-tion cabinets. These inverters are in turn powered from station batteries.
t
- - ~. _
. The feedwater flow indications to each steam generator and the backup level channels are tested and calibrated during each refueling outage.
Each Auxiliary Feedwater channel provides an indication of feed flow with an accuracy on the order of + 10%.
The licensee has satisfied this requirement.
2.1.8.a IMPROVED POST-ACCIDENT SAMPLING CAPABILITY A design review of post accident sampling was conducted by Sargent and Lundy.
Interim methods have been developed for sampling both reactor coolant and containment atmosphere; the sampling procedure (ZCP-500) is approved.
Interim methods (Procedures ZCP-123A and ZCP-23A) have been developed for analyzing the highly radioactive samples.
Radio-isotopic analysis will be performed on both kinds of samples. Also, the gaseous samples will be analyzed for hydrogen and the liquid samples will be analyzed for boron. Minor modifications, including temporary shielding, have been completed.
The licensee is in compliance with this requirement.
OIE will review the adequacy of the sampling procedures and verify training of operating personnel.
2.1.8.b INCREASED RANGE OF RADIATION MONITORS Interim methods for monitoring releases have been developed. The proce-dures have been written and the equipment is in place. Attention was directed to monitoring releases from the auxiliary building on the grounds that all other release points could be isolated. There are provisions for sampling the air ejector effluent. Procedure E0P 10 covers estimating releases from the steam dump. Releases from the reactor building, the gas decay tanks and miscellaneous locations would be via the stacks.
All potential release points are monitored by the interim methods. The range and test requirements and intervals are acceptable.
Backup provisions have been made for instrumentation not on emergency power.
Provisions have been made to prevent personnel overexposures. A commit-ment is made to meet the 1/1/81 deadline for compliance with Category "B" requirements.
OIE will verify that the equipment has been installed, that procedures and training are acceptable.
The licensee is in compliance with this requirement.
2.1.8.c IMPROVED IN-PLANT IODINE INSTRUMENTATION An improved in-plant iodine monitor system is being implemented which meets.the NRC position. The present system is to collect samples on
. charcoal cartridges; flush the cartridges with clean gas to remore noble gases; and count with the spectrometer in the counting room.
An alternate counting location is available. The system is being improved by the purchase of two Eberline SAM-2 radiciodine monitoring units. Also, silver zeolite cartridges are being obtained.
OIE will verify that the SAM-2 units and silver zeolite cartridges are availekle for use and that the procedures (RP-1310-11) has been revised
.o aflect changes discussed during the site visit, including the flushing of charcoal cartridges with clean gas where appropriate.
The licensee is in compliance with this requirement.
REACTOR COOLANT SYSTEM VENT The licensee has provided the design for the reactor coolant system (RCS) vent and has addressed'all of the clarification items in the October 30, 1980 clarification letter.
2.2.1.a SHIFT SUPERVISOR RESPONSIBILITIES During the site visit on January 21 and 22,1980, it was determined that directives and procedures necessary to meet this requirement are acceptable.
2.2.1.b SHIFT TECHNICAL ADVISOR The licensee has fully implemented the Shif t Technical Advisor (STA) requirement. STAS are on shift and available in the control room within 10 minutes following an accident.
2.2.1.c SHIFT RELIEF AND TURNOVER PROCEDURES Shift and relief turnover procedures were reviewed and found acceptable during the site visit.
2.2.2.a CONTROL ROOM ACCESS The licensee has modified procedures for implementing control room access requirements and is in conformance with this requirement.
2.2.2.b ONSITE TECHNICAL cUPPORT CENTER The interim onsite technical support center (TSC) has been established.
in the conference room of the administration building at the Zion plant.
This area is readily available to the document center where pertinent plant records and drawings of plant area layouts, systems and equip-ment are available. Procedure EPIP 300-3 provides plans for engineering /
management support and staffing of the TSC.
. Radiation equipment for monitoring airborne contamination and direct radiation is available in the TSC. Three communication links exist between the TSC.and the control room: a dedicated telephone link, the regular station telephone and a sound-power telephone. Dedicated communication between the TSC and NRC Operations Center in Bethesda has been established.
The licensee has prepared procedures which call for direct communic.tions
'(tclephone) between knowledgeable individuals in both the control room and TSC to ensure the reliable and timely t.ransmittal'of plant informa-tion to the interim TSC. The plant parame:er presentation for the long term TSC will be by color graphics CRT displays. Two high speed line printers will provide hard copy records, one for alarm displays and one for a user input / output interface.
Procedure EPIP 300-4 which has been implenented provides plans for performing accident assessment functions an the TSC and the control room should the interim TSC become uninha',itable.
The licensee has satisfied this requirement.
2.2.2.c ONSITE OPERATIONAL SUPPORT CENTER The licensee has designated the employee's lunch room in the admini-stration building as the on-site operational support center. Communica-tion equipment between this area and the control room is available.
A procedure which describes the activation, manning, and use of the operational support center has been implemented.
The licensee has satisfied this-requirement.
4 t
e b
l
4 REFERENCES ZION LESSONS LEARNED IMPLEMENTATION
'l.
Letter, D. L. Peoples to Darrell G. Eisenhut, dated 10/19/79 forwarding responses to short term Lessons Learned requirements.
2.
Letter, Cordell Reed to Director, NRR, dated 11/21/79, commitments to meet ~near term Lessons Learned Task Force requirements.
3.
Letter, CordellIReed to Director, NRR, dated 11/30/79, Supplementary Response to Near Term Lessons Learned Requirements.
4.
Letter, D. L. Peoples to Director, NRR, dated 12/3/79, Supplement to Reference 1.
5.
Letter, D. L. Peoples to Darrell G. Eisenhut, dated 12/14/79, response to request for additional information on Auxiliary Feedwater Systems.
6.
Letter, D. L. Peoples to Director, NRR, dated 12/17/79, commitment to complete all short term Lessons Learned items before 12/31/79 or before returning to power.
-7.
Letter, D. L. Peoples to Director, NRR, dated 1/1/80, documents completion of all short term Lessons Learned requirements.
8.
Letter, D. L. Peoples to Director, NRR, dated 2/22/80, additional documentation of short-term Lessons Learned requirements.
9.
Letter, D. G. Eisenhut to all Operating Power Plants, dated 9/13/79,
]
Defining Short Term Lessons Learned Requirements.
J j
10.
Letter Director, NRR to all Operating Power Plants, dated 10/30/79, i
Discussion of Short Term Lessons Learned Requirements.
i i
1 e
-r v.
er-
~.
ENCLOSURE 2
~
ATTENDANCE LIST SITE VISIT JANUARY 21 and 22
-STATUS OF CATEGORY A LESSONS LEARNED ITEMS ZION STATION
_Name Company I Pieck CECO L. Scott CECO T. Tramm CECO X. Polanski CECO W.-A.
Nestel CECO L. Soth CECO P. R. Kuhner CECO J. Marianyi CECO B. Brasher CECO F. Rescek CECO B. Schramer CECO F. Lentir e CECO i
J. Woods CECO S. Miller CECO C. E. Schumann CECO T. M. Parker CECO J. J. Gilmore CECO E. Fuerst CECO E. Reeves NRC/NRR N. Anderson NRC/NRR J. F. Burdoin NRC/NRR M. B. Fields NRC/NRR J. Kerrigan NRC/NRR C. A. Willis NRC/NRR A. Stalker EG&G J. Kohler NRC/lE 2
l e
a i
i-wr y
-w
-sw-
-,p,
~r v
e
-,e----~~>
r s
s~rr-
-mww-