ML20010C903
| ML20010C903 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Callaway  |
| Issue date: | 08/13/1981 |
| From: | Edison G Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8108210194 | |
| Download: ML20010C903 (21) | |
Text
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AUG 131981 Docket Hos.:.iSTN 50-482. _
STil 50-483 l
and STN 50-486 APPLICA!4TS: Union Electric Company Kansas Gas and Electric Company FACILITIES: Callaway Plant, Unit 1 and Unit 2 Wolf Creek Generating Station, Unit 1
SUBJECT:
SUMMARY
OF DESIGN REVIEW IIEETING HELD Oil JULY 16, 1981, WITil CALLAWAY AND WOLF CREEK APPLICANTS REGARDIhG ELECTRICAL POWER SYSTEMS A meeting was held on July 16, 1981 at the Bechtel offices ir$ Gaitharsburg, Maryland with representatives of the Union Electric Company, Kansas Gas and Electric Company, SNUPPS Organization, Bechtel Power Corporation and Westing-house Electric Corporation. A list of 18 ite:as (discussion areas) was provided prior tn tte meeting.
The list of items served as the agenda for this necting (provided as Enclosure 1). The list of attendees at the meeting is attacned as.
At this meeting some additional items were identified and discussed.
These are numbered in this sunt.1ary be3 nning witn item 19.
i A discussion of tne various items of interest follows.
I ten 1 Inis question and the applicants' response applies only to Callaway Units 1 ar.d 2 -
Tne applicant stated that each of the safeguard transformers (A a d) in the switchyard is sized with sufficient capacity to handle the design safe shutdown loads on one Callaway Unit and the design basis LOCA loads on the other Callaway Unit.
Callaway Site Addendum Section 8.2.1.2 describes the rating of the safeguard transforraers. Figure 8.3.2 of the SuuPPS FSAR lists the luads. A comparison of these is the basis for the applicants statement. NJ further information is required on this item.
Item 2 The applicants responded as follows:
-Callaway:
The grid is capable of withstanding the outage of the largest station (botn Callaway unics). This is stated in the Callaway Site Addendum Section 8.2.2.2.
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Wolf Creek: The grid is capable of withstanding the outage of the Wolf Creek Unit or the largest station. This is stated in the Wolf Creek Site Addendum Section 8.2.2.1.
No further information required.
Item 3 The applicants responded as follows:
Tne FSAR site adaer.da for Wolf Creek and Callaway, and the SNUPPS FSAR, will be revised to provide a description and results of ana-lysis of the circuits from the switchyard to the transformer (as stated in the question). No further question on this item.
Item 4 A minor re(isibn to the question noted that IEEE 308 section 5.2.3(5) sas intendeo, not section 5.3.2(5). The Callaway and Wolf Creek Site Addenda (Section 8.2) will be revised to describe the additional monitoring of those offsite circuits from the switchyard to the onsite distribution system as well as the switch-yard itself. The SNUPPS FSAR Section 8.2 will be revised to refer the reaCar to all sections where th offsita system is described.
Item 5 The applicants stated that they have designed the offsite power system to NRC regulations and do.mt believe the NRC position to be justified. NRC informed the appiicants that we would advise them under separate cover if a. f9rmal NRC position is developed.
The applicants further added the folloding justification:
The SNUPPS design utilized a load sequencer for connecting each load group of safety-related loads onto their associated bus regardless of the source of power to that bus. This sequencing feature minimizes the system disturbance and provides the most stable means of starting the safety loads. The ESF transformers have each been sized to carry both safety-related load groups simultaneously. This sizing criteria does not provide a capacity suf ficient to start all safety-related loads simultaneously.
This design feature is sell within the bounds of the HSSS accident analysis. When sequencing safety-related loads onto the bus, whether onto the diesel or onto the offsite network, tne starting times of all loads is less thm that required by the analysis.
If offsite power is available, the sequencing of loads cor.inences imediately with the SIS accident signal. No time delay associated with diesel generator start would be encountered in this case.
Item 6a The applicants stated they comply with Reg. Guide 1.9 based on infor-mation in FSAR Section 8.1.4.3 item b under regulatory guide 1.9.
We have no further quastions.
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e Iten 6b The applicants stated that tney comply with ILLE 387 because the diesel will return to autoaatic control if a start signal is re-ceived (as a result of an accident, for example) while the diesel is in test. UdC has no further questions.
Item 6c The applicants sta*.ed they would discuss this furthe and advise i
NRC.
The item remains open.
l Item 6d The FSAR will be revised to clarify that the applicants do comply t
with IEEE standard 387-1977. The Power Systems Branch will require HRC audit verification of the 300 start and load test which will be included ia a general open item for audits and verifications of se-lected drawings analyses, and tests at the sites. We expect to request the Office of Inspection and Enforcecent to review the test i
report.
Iten 6e The 7 day,12000 hour, and 30 minutes ratings are 6821 kw, 6635 kw, and 744i kw, respectively. The applicant will revise the FSAR to document these ratings and to note that tests were perforned to run the diesel generator for two hours at the 7-day rating, which is 10%
dbove tne Continuous operation rating.
The 2-hour rating is there-fore at least 10% above the continuous operation rating.
URC has no further questions on tnis item.
Iten 6f The FSAR will be revised to state that the margin in the test loading is at least 10% greater than tne most severe single step load. No further questions.
Item 69 The FSAR will be revised to state tndt the 22 hour2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> test was conducted af ter equilibruta was established.
Item 6h The FSAR will be revised to provide justification for not bypassing the three protective devices. The applicants stated that they be-lieve this is a safer design than bypassing these three devices.
No further questfons.
Iten 61 The applicants stated that they can and will simulate all parar.eters of operation outlined in Reg. Guide 1.108 during inservice tests.
We have no further questions.
Item 7 The applicants stated their intent to neet these NRC positions in a meeting held December 9 and 10,1980 on this same subject. They reaffirmed their intent during this latest meeting. We expect to request the Office of Inspection and Enforcement to review the test results of the voltage measurements. This will be included in the general open item (see item 6d) for verification at the sites of I
selected drawings, analyses, and tests.
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-lhe' applicants stated that they comply with the position in this l
draft question. They stated that the disel generator local instru-l ments and controls are isolatable from those in the control room, j
and no fault (short or open) in the control room could degrade the l
1 solation. We have no further questions.
1 Item 9 The applicants stated they comply and will revise the FSAR to clearly state this compliance.
Item 10 The applicants will submit the test report on electrical penetra-tions which demonstrates compliance with Reg. Guide 1.63, Rev. 2 and conformance to IEEE 317-1976.
The applicants pointed out that requirements for locking out power l
are already described in FSAR Section 8.1.4.3 and no FSAR revision is required. The FSAR will be revised to address the adequacy of the design as it relates to inde,v,adence of protective devices (fuses and circuit breakers). Testing of protective devices will be described in the Tech. Specs. 6.1d no FSAR revision is required.
Item lla The emergency busses are capable of supplying power to selected non-class IE loads during non-accident conditions, with and without offsite power. These loads are supplied through qualified isolation devices that are opened upon an SIS signal. Upon loss of offsite power, most of these non-safety related loads are dropped from the safety related busses by the load shedder or as a consequence of the power loss, and must be manually re-loaded if requred.
The isolation devices used are fully qualified, environmentally and seismically, and will function to separate any connected non-safety related load from the safety busses upon a fault on the non-safety portion of the circuit when no accident is present. The diesel generators have sufficient capacity to supply all connected safety and non-safety related loads continuously.
Thus no credit need be taken for load shedding of non-class IE loads for the purpose of generator loading.
Since the class IE load groups are fully redundant and independent, no single failure will prevent the class IE system from performing its safety function.
In addition, the test report will be submitted to NRC which demonstrates that the class IE system will not be degraded below an acceptable level.
I tem 11b The FSAR will be revised to specify the separation distance required i
between class IE and non-class IE circuits.
In addition, FSAR Section 8.1.4.3 will be revised to note that section 5.6 (not just 5.6.2) of IEEE 384-1974 is complied with. No further questions.
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Iten 11c FSAR Section 8.3.1.3 will be revised to state that flon-class IE cables are separated froa class IE cables using the same minimum distonce separation requirements as are used between redundant class IE circuits. We have no further questions.
Item 11d The FSAR will be revised to clarify the color coding. No further questions.
Iten 11e The applicants state that cables and raceways were narked prior to installation. No FSAR revision is required. No further questions.
I teu lif The applicants stated tney couply.
We have no further questions.
Item lig The applicants stated that means of unique identification are provided for separation groups. No further questions.
Item 11h The applicants stated that they comply with IEEE'384-1974 when cables dpprodch Control pdnels, and will revise the FSAR to describe how they comply.
In the case of control boards and panels, the applicants state they comply with IEEE 384-1974. However, IMC stated that we believe nore space may be required between the cable and the conduit. We will consider this further and aavise the applicants. This item remains open.
Iten 111 The applicants stated that circuits beyond isolation devices are not treated as Class IE and will not be again routed in Class IE raceways.
nssociated circuits that are not powered through an isolation device are treated using Class IE criteria. We have no further questions.
Iten lij We agreed that WCAP-8892-A is applicable to SNUPPS plants and should be adequate Justification. We have no further questions.
Iten lik The applicants stated tnat protection system inputs and outputs are routed in different trays and conduits. We have no further questions.
Iten 12 We dropped our request for instrument (1) (battery charger output volt-age (voltmeter)) because it duplicates the DC bus voltage voltmeter al-rsady provided. The applicants stated they have instrument (2) (battery current (ammeter charger). For instrunent (3) (batte y high discharge rate alarm), the applicants believe this will not add significant pro-tection that does not already exist. We indicated we would consider this further, and this itea remains open.
Iten 13 The applicants stated the DC systens comply with Reg. Guide 1.75.
No further questions.
Item 14 The F5AH will be revised to state the eyewash facility is located in the corridor between roous, not in the battery rocas.
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Item 15 This item remains open. The applicants will provide analyses and additional justification for their battery s1ZC. We maintained that d battery size 50". greater than required capacity is needed.
Iten 16 The applicants responded as follows:
Callaway For cases 1 and 2, the applicant stated that the primary and backup protection would both trip at the same time; thus, power to the Class IE busses would not be lost. For case 3, if safeguard transformer
'B' were out of service at the time of the breaker failure, all offsite pcwer would be lost to the Class IE busses. The applicant stated that power could be recovered in about 20 minutes.
Wolf Creek The applicant stated that two separate switen yards exist so that off site power would not be lost for any of the 3 cases in the draft questions.
We stated we have no further questions for either applicant on this iten.
Item 17 The applicants stated that they were in compliance with IEEE 308-1974.
No further questions.
Item 18 The applicants will revise the FSAR to correct Table 8.3-1 as agreed in the meeting Auditional questions 19 through 23 were presented to the applicants at the meeting; these questions and the applicants' responses follow:
Item 19 Question Describe your degree of compliance with the recommendations of NUREG-0666.
Response
The applicants will subait a letter describing their compliance with the recommendations of NUREG-CR-0666.
Item 20 Question Describe your method for locking out power to motor operated valves required to meet the ECCS single failure criterion.
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Response
The applicants described their method and indicated PSAR Chapter 3 included a schematic. NRC indicated we would have to further con-sider this item, and tne item remains open.
Item 21 Question Describe how your underground routing of Class IE cables meets HRC criteria.
Response
The applicants responded as follows:
Gallaway The routtng is described in sections 3.8.4 and 3.8.5 and figure 3.8-4 of the Callaway site addendum.
Wolf Creek The routing is described in section 3.8.4 ano figures 3.8-4 and 3.8-S of the Wolf Creek Site Addendum.
No further quertions.
Iten 22 Question Verify, that the protection is provided to Class IE equipment frou design basis events.
Response
The applicants stated this is described in FSAR Section 8.1.4.3.
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Itea 23 Question Confirm your compliance with IMC requirerents regarding submerged Class IE equipment ret,uired for safe shutdown.
Response
The applicants stated tney couply. One piece of Class IE equipuent is required to operate when submerged ana it is qualified.
ido further questions.
Original signed bg Gordon E. Siison,/
G. E. Edison, Project llanager Licensing Granch flo. 1 Division of Licensing cc: See next pege l
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Mr. J. K. Bryan Mr. Glenn L. Koester Vice President - f;uclear Vice President - fluclear Union Electric Company Kansas Gas and Electric Company P. O. Box 149 201 florth Market Street St. Louis, Missouri G3166 P. O. Box 208 i
Wichita, Kansas 67201 cc: Gerald Charnoff, Esq.
i Shaw, Pittman, Potts, Dr. Vern Starks Trowbridge & Madden Route 1, Box 863 1800 M Street, fl. W.
Ketchikan, Alaska 99901 Washington, D. C.
20036 fir. Hillian Hans Kansas City Power & Light Company U. S. Nuclear Regalatory Commission ATTfh Mr. D. T. ficPhee Resident Inspectors Office Vice President - Production RR #1 1330 Baltimore Avenue Steedman, flissouri 65077 Kansas City, Missouri 64141 i
Ms. Treva Hearn, Assistant General Counsel Mr. Nicholas A. Petrict.
Missouri Public Service Commission Executive Director, SilVPPS P. O. Box 360
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5 Choke Cherry Road Jefferson City, Missouri 65102 Rockville, Maryland 20850 i,
Jay Silberg, Esquire Mr. J. E. Birk Shaw, Pittman, Potts & Trowbridge Assistant to the General Counsel 1800 M Street, fl. W.
i Union Electric Company Washington, D. C.
20036 St. Louis, flissouri 63166 Mr. D. F. Schnell Kansans for Sensible Energy Manager - I;uclear Engineering P. O. Box 3192 Union Electric Company Wichi ta, Kansas 67201 P. O. Box 149 St. Louis, Missouri 63166 Ms. Mary Ellen Salava Route 1, Box 56 Mr. Tom Vandel Burlington, Kansas 66839 Resident Inspector / Wolf Creek NPS c/o USf!RC Eric A. Eisen, Esq.
P. O. Box 1407 Birch, Horton. Bittner & Monroe Emporia, Kansas 66801 1140 Connecticut Avenue, fl. U.
Washington, D. C.
20036 Mr. Michael C. Keener i
Wolf Creek Project Director i
State Corpornion Cor. mission Ms. Wanda Christy State of Kansas 515 H.1st Street Fourth Floor, State Office Building Burlington, Kansas 66339 I
Topeka, Kansas 66612 1
4 I
r' ENCLOSURE 1 POWER SYSTEMS SRANCH DRAFT QUESTIONS FOR CALLAWAY - WOLF CREEK DESIGN REVIEW MEETING JULY 16, 1981 1
- 1. Sharing of Offsite Circuits Between Units Tn regaW to Criterion 5 of the GDC, the Callaway design permits sharing of offsite circuits between Units 1 and 2. Even though the offsite circuits are riormally not shared, design provisions do exist to permit sharing. Both units can be supplied by one safeguard transformer located in the switchyard. It is our position (pursuant with GDC 5 and section 8.1 of IEEE Standard 308-1974) that each of the safeguard transformers be sized with sufficient capacity to i
supply all connected Class IE and non-Class IE loads of botn Class 1E divi-sions. Describe your compliance with our position.
1
- 2. Electrical Grid System Stability i
The Union Clectric Company electric grid system consists of interconnected hydroelectric and fossil-fueled plants supplying electric energy over a 345/161
/138 kilovolt transmission system. This grid system is an integral part of the midwest interconnected utility grid with a number of supporting grid interties, i
j The applicant has conducted loac' flow and transient stability analyses showing that the loss of one or the loss of both Callaway units while carrying full load will not af fect the stability of the Union Electric Company grid or the ability to provide offsite power to the Callaway plant. It is our position i
(position 2 of Branch Technical Position ICSB 11 (PSB)) that the grid be i
capable of withstanding the outage of the largest unit. It is our cor ern that
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Callaway may not be the largest unit. Provide clarification.
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- 3. Capacity and Capability of Offsite Circuits i.
Th'e"offsite power system circuit's"from and includir.g the ESF transformers and
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from and including the startup transformer through the ESF transformer to the j
onsite Class 1E a-c power distribution system is part of (and is evaluated i
with) the SNUPPS standardized design. In regard to these circuits, a system l
description and an analyses sufficient to demonstrate compliance with 10 CFR 50 has not been provided in Section 8.2 of the SNUPPS FSAR. This item was dis-cussed with the applicant and was addressed on page 179 of the December 10, i
1980 transcript of the Independent Design Review (IDR) meeting. Similarly, a system description and analysis sufficient to demonstrate compliance to 10 CFR I
50 has not been provided in Section 8.2 of the Callaway addendum to SNUPPS j
FSAR for the offsite power circuits from the switchyard to the startup trans-l former and to the ESF transformers. Provide the subject description and analy-sis in Section 8.2 of the FSAR. The description and analysis should include but s
not be limited to the capacity of the safeguard and startup transformers to supply all Class 1E and non-Class IE connected loads and control power to l
circuit breakers.
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- 4. Surveillance i
Tfie switchyard battery system is monitored in the control room by alarms. These l
alarms include a battery charger alarm and battery voltage alarm. Additional 1
monitoring of the offsite system, that may be available to assure that the system is ready to perform its intended function in accordance with section 5.sf(5')ofIEEEStandard 308-1974, has not been described in the FSAR. Provide 3
the subject description.
2
- 5. It is the staff positio6 that'the offsite power system have sufficient capacity to supply all required loads without sequencing of loads. The Callaway - Wolf Creek design permits sequencing of loads on the offsite power system. Justify your design.
- 6. Compliance With Guidelines of Regulatory Guide 1.9, Revision 1 t
a.
In accorda~n~ce with position 5 of Regulatory Guide 1.9, Revision 1, and sections 5.6.1.3 and 6.3.1(3) of IEEE 387-1977, the diesel generators continu-ous rating load rejection test should demonstrate that the speed of the diesel does not exceed 75 percent of the difference between nominal speed and the overspeed trip setpoint, or 15 percent above nominal, whichever is lowar.
Secthns 8.3.1.1.3 and 8.1.4.3 of the FSAR, however can be interpreted to mean that a speed that does not cause damage to moving parts is acceptable. This 4
interpretation does not meet the guidelines of Regulatory Guide 1.9. It is our position that an explicit statement of compliance must be documented in the FSAR or that deviations fron Regulatory Guide 1.9 and IEEE Standard 387-1977 must be documented in Section 3A of the FSAR. This item was discussed with the applicant as indicated on page 68 and 69 of the transcript of the December 10, 1980 design review meeting. Prcvide the subject documentation.
- b. In accordance with section 5.6.2.2 of IEEE Standard 387-1977, it is required that the start-diesel signal return control of the diesel generator unit to the automatic control system except in modes such as the repair and maintenance manual operating mode. It appears, based on Section 8.1.4.3 of the FSAR and pages 80 through 82 of the tran.,cript for the December 10, 1980 independent design review meeting, that the Callaway - Wolf Creek diesel generator control does not meet this requirement of IEEE Standard 387. It is our position that an explicit statement of compliance must be documented in the FSAR or the devia-tion from section 5.6.2.2 of IEEE Standerd 387-1977 must be documented with justification in Section 3A of the FSAR. Provice the subject documentation.
- c. In accordance with sections 5.1.2(3) and 6.3.1(4) of IEEE Standard 1
387-1977, it is required that the diesel generator units h6ve the capability of accepting i
design load following operation at light load or no load for an acceptable time. Sections 8.1.4.3 and 8.3.1.1.3 of the FSAR do not address light or no load operation of the diesel generator. As indicated on page 96 of the December 10, 1980 independent design review meeting, no load tests have been performed and are to be addressed in response to NUREG/CR-0660. NUREG/CR-0660 addresses no load and light load operation for diesel generators during periodic testing and emergency operations. The NUE: 3jaddresse the ability of diesel generators i
to carry no load. Describe arr $stify this apparentTnon-compliance with IEEE Standard 387-1977 Q, Q ggg
- d. In accordance with sections 6.3.2(l) and 6.3.2(2) of IEEE Standard 387-1977 it is required as part of the 3o. valid start and load tests that the diesel
'i generator be capable of accelerating to specified frequency and voltage within the required time inte val af ter a start signal and immediately following be J
capable of accepting a step load equal to or greater than 50 percent of the continuous rating with voltage and frequency stabilized to within specified 2
limits within the required time interval. Section 8.3.1.1.3 of the FSAR defines a valid start and load test to be a start with 50 percent loading within the l.
required t ime interval. This FSAR definition is not consistent with IEEE Standard 387-1977. Is is our position that en explicit statement of compliance must be documented in the FSAR or the deviation from section 6.3.2(2) of IEEE Standard 387-1977 must be documented with justification in Section 3A of the FSAR. / W ite 7mf N'**'7'N
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- e. Provide the short time or two hour rating of the diesel generator in the FSAR.
f.In accordance with section 6.3.3 of IEEE Standard 387-1977, the margin test load should be at least 10 percen loadwithinthedesignloadfMdM(on.Section8.3.1.1.3oftheFSARindicatesgreater than the mos only that We a$.Y is to be used for the margin test load. It.is our position that the margin test load be greater than 10 percent ef the most severe single step load. Justify your non-compliance with our position.
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In accordance with section 6.3.1(1) of IEEE Standard 387-1977, the time required to reach engine temperature, equilibrium plus 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> should be used as the time used to demonstrate the capability of the diesel generator to carry rated load. Section 8.3.1.1.3 of the FSAR indicates only 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> for the rated load tests. It is our position that the rated load test include the time for the diesel generator to reach temperature equilibrium plus 22 hoars. Justify your non-compliance with our position.
- h. A number of tripping devices have been provided for each diesel generator as i
indicated in Section 8.3.1.1.3 of tne FSAR. The majority of tripping devices are either bypassed during accident conditions or actuated by two-out-of-three logic. These devices meet position 8 of Regulatory Guide 1.9, Revisicn 1 and are acceptable. However, three protective devices are actuated by one-out-of-one logic, are not bypassed during accident conditions, and are not in compli-l ance with position 8 of Regulatory Guide 1.9, Revision 1. In justification of l
this non-compliance, the applicant documented in the FSAR that should one diesel generator be tripped by a protective device, the redundant load group will function as a backup. We find this justification to be unacceptable. It is our concern that these protective devices could interfere with the successful functioning of diesel generators when they ore most needed, i.e., during an accident condition. The criterion should be to provide st andby power when I
needed to mitigate the effects of an accident condition rather than to protect l
the diesel-generators from possible damage. Thus, it is our position that these l
protective devices be bypassed during acc ident cond it ions. This item was addressed on pages 69, 70, 71, and 72 of the transcript to the December 10, l
1980 indeoendent design review meeting. Provide additional justification for your non-compliance with our position.
- i. In accordance with position 7 of Regulatory Guide 1.9, Revision 1, design provisions should exist so that testing of the diesel generators will simulate the parameters of operation outlined in Regulatory Guide 1.108. Section 8.1.4.3 of the FSAR indicates that inservice tests will comply with the requirements of Regulatory Guide 1.108 but does not specifically indicate that the Callaway -
Wolf Creek design is such that all parameters of operation outlined in Regula-tory 1.108 can be simulated. In this regard, it is our position that when the diesel generator is in the periodic test mode paralleled to the off site power system, the diesel will be capable of supplying emergency power within the required time given an accident signal.
4
- 7. Low and/or Degraded Grid Voltage The Millstone, Unit 2 (Docket No. 50-336) hw grid voltage occurence 5rought into focus the potential common mode failure of redundant safety-related electrical equipment that could result from a degraded grid voltage condition.
This occurance prompted us to develop various positions to assure that the requirements of Criterion 17 Of the General Design Criteria will be satisfied I
with regard to making provisions to minimize the probability of losing electric l
power from any of the ramaining supplies as a result of, or coincident with, i
the loss of power generated by the nuclear power unit, the loss of power from the transmission network, or the loss of power from the orsite electrical power supplies. These provisions for maintaining the independence between the offsite
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and onsite emergency power supplies are emphasized in IEEE Standard 308-1974, 1
" Criteria for Class 1E Power Systems for Nuclear Power Generating Station,"
which states that preferred offsite and the standby onsite emergency power supplies shall not have a common mode failure between them.
The following positions that we have developed are being used in the evaluation of electrical power designs for operating plants, and construction permit and operating liocense applications. Describe how the Callaway - Wolf Creek design meets these postions. The design of the undervoltage trip system was discussed on pages 17-22 and 74-76 of the transcript of the December 10, 1980 independent
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design review meeting.
- 1. In addition to the undervoltage scheme provided to detect loss of offsite power at the Class 1E busses, a second level of undervoltage protection with time delay should also be provided to protect the Class lE equipment; this second level of undervoltage protection shall satisfy the following criteria:
a)The selection of undervoltage and time delay setpoints shall be determined from an analysis of the voltag.e requirements of the Class lE loads at all onsite system distribution levels; J
b)Two separate time delays shall be selected for the second level of under-I voltage protection based on the following conditions:
1)The first time delay should be of a duration that establishes the existance of a sustained degraded voltage conditico (i.e.,
something i
longer than a motor starting transient). Following this delay, an alarm in the control room should alert the operator to the degraded condition.
The subsequent occurence of a safety injection actuation signal (SIAS) should immediately separate the Class lE distribution system from the offsite power system.
l 2)The second time delay should be of a limited duratior such that the permanently connected Class lE loads will not be damaged. Following this delay, if the operator has failed to restore adequatt voltages, the Class lE distiibution system should be automatically separated from y
the offsite power system. Bases and justificaticn must be provided in support of the actual delay chosen.
c)The voltage sensors shall be designed to satisfy the following plicable
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requirements derived from IEEE Standard 279-1971, " Criteria for Protection Systems for Nuclear Power Generating Stations":
- 1) Class IE equipment shall be utilized and shall be abysically located at and electrically connected to the Class IE switchgear.
2)An independent scheme shall be provided for each division of the Class 1E power system.
3)The undervoltage protection shall include coincidence logic on a per bus basis to preclude spurious trips of the offsite power source.
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i 4)The voltage sensors shall automatically initiate the disconnection of offsite power sour,ces whenever the voltage set point and time delay limits (cited in item 1.b.2 above) have been exceeded.
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- 5) Capability for test and calibration during power operation shall be i
provided.
- 6) Annunciation must be provided in the control room for any bypasses incorporated in the design.
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d)The Technical Specifications shall include limiting conditions for opera-l tions, surveillance requirements, trip setpoints with minimum and maximum l
limits, and allowable values for the second-level-voltage protection sensors l
and associated time delay devices.
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- 2. The Class 1E bus load shedding scheme should automatically prevent shedding during sequencing of the emergency loads to the bus. The load shedding feature should, however, be reastated upor, completion of the load sequencing action.
The Technical Specifications must include a test requirement to demonstrate the operability of the automatic bypass and reinstatement features at least once per 18 months during shutdown.
In the event an adequate basis can be provided for retaining the load shed feature during the above transient conditions, the setpoint value in the Technical Specifications for the first level of undervoltage protection (loss of offsite power) must specify a value having maximum and minimum limits. The basis for the setpoints and limits selected must be documented.
- 3. The voltage levels at the safety-related buses should be optimized for the maximum and minimum load conditions that are expected throughout the aqtici-l pated range of voltage variations of the offsite power sources by appropriate adjustment of the voltage tap settings of the intervening transformers. The tap settings selected should be based on an analysis of the voltage at the termin-als of the Class 1E loads. The analyses performed to determine minimum operat-ing voltages should typically consider maximum unit steady state and transient loads for events such as a unit trip, loss of coolant accident, startup or thutdown with the offsite power supply (grid) at minimum anticipated voltage and only the offsite source being considered available. Maximum voltages should be analyzed with the offsite power supply (grid) at maximum expected voltage concurrent with minimum unit loads (e.g., cold shutoown, refueling). A separate set of the above analyses should be performed for each available connection to the offsite power supply.
- 4. The analytical techniques and assumptions used in the voltage analyses cited in item 3 above must be verified by actual measurement. The verification and test should be performed prior to initial full power reactor operation on all sources of offsite power by:
a) loading the station distribution buses, ircluding all Class 1E buses down to the 120/208 v level, to at least 30%;
I b) recording the existing grid and Class 1E bus voltages and bus loading down to the 120/208 volt level at steady state conditions and during the starting i
of both a large Class 1E and non-Class 1E motor (not concurrently);
Note: "o minimize the number of instrumented locations, (recorders) during the motor starting transient tests, the bus voltages and loading need only be recorded on that string of buses which previously showed the lowest analyzed voltages from item 3 above.
c)using the analytical techniques and assumptions of the previous voltage analyses cited in item 3 above, and the measured existing grid voltages and
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bus loading conditions recorded during conduct of the test, claculate a new set of voltages for all the Class 1E buses down to the 120/208 volt level; d) compare the analytically derived voltage values against the test results.
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With good correlation between the analytical results and the test results, the test verification requirement will be met. That is, the validity of the mathematical model used in performance of the analyses of item 3 will have been established; therefore, the valiJity of the results of the analyses is also established. In general the test results should not be more than 3%
lower than the analytical results; however, the difference between the two when subtracted from the voltage levels determined in the original analyses should never be less than the Class lE equipment rated voltages.
- 8. Electrical Independence Between Local.and Control Room Panels The FSAR indicctes that equipment is prov;ded locally at each diesel generator for manual starting of the diesel in case of a control room evacuation. It is our position that the diesel generator's local instruments and controls be electrically isolatable from the instruments and controls located in the control room so that any failure of the circuitry, located in the control room or between the local station and the control room, will not affect the capabil-ity of starting and loading the diesel generator from the local s t r.t ion.
- 9. Comoliance with Position 4 of Regulatory Guide 1.63, Revision 2
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The applicant has indicated in Appendix 3A of the FSAR that the elctrical pene! rat ions for the Callaway and Wolf Creek plants meets Regulatory Guide 1.63, Revision ? with the exceptio., of position 4. The medium voltage pm etra-tion assemblies are not designed to withstand the impulse withstand test described in position 4 of Regulatory Guide 1.63, Revision 2.
However the penetrations are designed for "BIL" withstand. Provide the meaning of "BIL" and i
the justification for the exception to position 4. This item was also addressed
- p:p 130 of the transcript for the December 9, 1980 independent design review meeting.
i
- 10. Reactor Containment Electrical Penetrations Criterion W W ~the General Design Criteria requires, in part, that the reactor
~
containment structures, including electrical penetrations, be designed so that the containment structure and its internal compartments can accommodate, without failure, the pressure and temperature conditions resulting from any loss-of-coolant accident. Therefore, electrical penetration assemblies are designed to withstand, without the loss of mechanical integrity, the maximum available f ault current versus time conditions that could occur given single random failures of circuit overload protective devices as recommended by Regulatory Guide 1.63, Revision 2,
" Electrical Penetration Assemblies in Containment Structures for Water-Cooled Nuclear Power Plants."
The applicant has indicated in Section 8.1.4.3 of the FSAR and pages 117 through 145 of the transcript for the December 9 independent design review meeting that the electrical penetrations for the Callaway - Wolf Creek plants conforms with IEEE Standard 317-1976 and meets Regulatory Guide 1.63, Revision i
2 with respect to the capability of electrical penetration assemblies to withstand maximum possible fault current versus time conditions. In order for us to complete our review in this area, we require coordinated f ault current versus time curves for each representative type cable. For each cable the curves must show the relationship of the fault carrying capability between
i 7
l the electric penetration, the primary overcurrent protective device, and the i
backup overcurrent protective device. Also, Technical Specification require-i ments for locking out power to equipment that is not required to be operational during normal operation, independence of primary and backup protective devices, and testability of protective devices needs to be addressed in the FSAR.
Provide the needed information.
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- 11. Compliance witn Regulatory Guide 1.75 a.) The Callaway - Wolf Creek design permits a number of non-Class 1E loads to be connected to Class IE power sources as indicated in Section 8.1.4.3 of the FSAR. The nejority of these circuits are isolateo by a circuit breaker that opens on an SIS signal. The circuits beyond the isolat ion device (circuit breaker) are treated as non-Class IE circuits and as such should be routed in non-Class 1E cable raceways. It is our concern that these non-Class 1E circuits may unnecessarily challenge and degrade redundant standby power supplies below an acceptable level on loss of offsite power when there is no SIS signal. Thus, it is our position that the non-Class IE circuits also be automatically discon-nected (so that they will not be automatically sequenced on loss of offsite power) or the circuits must be analyzed to demonstrate that the standby power supplies will not degrade Class 1E systems below an acceptable level.
The remaining non-Class 1E loads connected to Class IE sources include ac instrumentation loads. These loads as indicated in the FSAR are isolated by regulating type transformers. The FSAR states that a short circuit on the secondary will not cause an unacceptable influence on the Class IE system.
Provide the test report with results of tests that demonstrate that the Class 1C system will not be degraded below an acc%eptable level.
b.) Section 4.6.1 of IEEE Standard 384-1974 requires non-Class 1E circuits to i
be separated from Class 1E circuits, in part, by the minimum separat ion re-j quirements specified in section 5.6. Section 8.1.4.3 of the FSAR indicates that the Callaway - Wolf Creek design meets section 5.6.2 versus 5.6. Justify this l
j noncompliance with section 5.6 of IEEE Standard 384-1974.
i c.)Section 8.3.1.3 of the FSAR indicates that safety-related cables are unique-ly identified and separately routeo. Describe in Section 8.3.1.3 cf the CSAR how non-Class IE cables are uniquely identified and separated from Class 1E cables. The descript ion should include, but not be limited to, electric pene-trations, control boards and panels, cable spreading area, and general plant areas.
d.) Section 8.3.1.3 of the FSAR indicates that there are four separation groups with each group having its distinguishing color code. Define these colors specifi ally in Section 8.3.1.3 of the FSAR.
e.) In accordance with section 5.1.2 of IEEE Standard 364-1974, Class IE raceways and cables are required to be marked prior to the installation of cables. The FSAR is not clear as to tn' requirement that cables and raceways be marked prior to installation. Provice clarificat t n.
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_f.) Position 10 of Regulatory Guide 1.75 recommends that cables be color coded intervals not to exceed 5 ft. throughout the Eatire cable length. The FSAR at is not clear as to the interval of color coded markings. Provide clarification.
8 M Section 8.3.1.3 of the FSAR indicates that within a cabinet or panel which is associated and identified with a single sepuation group the internal wiring is exclusively associated with the same separation group and therefore, requires no further identification. For this cabinet or panel associated with a single separation group, describe how non-Class 1E cables are uniquely indentified h.) Section 8.3.1.3 of the FSAR permits separation of less than 3-foot horizontal or 5-foot vertical between redundant cables, when' the cables approach the same or adjacent control panels, provided one of the cables is installed in at enclosed raceway or conduit. Similar separation is allowed in control boards and panels. This separation does not meet IEEE Standard 384-1974 requirements. Justify the n,oncompliance, i. ) Sect ion 8.3.1.4.1.1 of the FSAR states that nonsafety-related cables are not routed through safety-related raceways. However, if a nonsafety-related cable is fed from a safety-related power service it may be routed through safety-related raceways of the same separation group as that of the power service. The above statement appears to not agree with Section 8.1.4.3 of the FSAR which indicates that circuits beyond an isolatiun device are treated per non-Class 1E and nonassociated criteria. Clarify this apparent disagreement.
J.) Section 8.3.1.4.1 of the FSAR indicates that within NSSS supplied safety-related racks and cabinets field run nonsafety-related shielded cables having
.3 synal of 100v or less are routed in common wireways with safety-related shielded cables routing with no physical separation. This cc.ble routing does not nieet the requirements of IEEE Standard 384-1974. In justification of this method of routing, WCAP-8892-A, " Westinghouse 7300 Series Process Control System Noise Tests," has been referenced in the FSAR. It should be noted that WCAP-8852-A specifies compliance to IEEE Standard 384-1974; thus the justification is unacceptable. Provide accept-able justification for this apparent noncompliance to IEEE Standard 384-1974.
k.) Section 8.3.1.4.1.1 of the FSAR indicates that protection system channel inputs are separated from the solid state protection system train outputs. Define this separation.
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9 12.D 9ect Current Monitoring and Annunciation The specific requirements for d'irect current power system monitoring derive
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from the i
5.3.4(5) generic requirements embodied in Sections 5.3.2(4), 5.3.3(5), and of IEEE Standard 308-1974, and Regulatory Guide 1.47, " Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems."
In summary, these general requirements simply state that the direct current system (batteries, distribution systems,and chargers) shall be monitored to the extent that it is shown to be ready to perform its intended func-tion. Accordingly, the guidelines used in the licensing review of the direct current system designs are as follows:
The following indications and alarms of the Clas lE direct current power system status shall be provided in the control r..om:
(a)Batterycurrent(ammeter-charge /dicharge) t (b) Battery charger cutput current (ammeter)
(c)Directcurrentbusvoltage(voltmeter)
(d) Battery charger output voltage (voltmeter)
(e) Battery high discharge rate alarm (f) Direct current bus undervoltage and overvoltage alarm (g) Direct current bus ground alarm (for ungrouned systec)
(h) Battery b eaker(s) or fuse (s) open alarm (i) Battery charger output breaker (s) or fuse (s) open alarm, and (j)
Battery charger trouble alarm (one alarm for a number of abnormal j
conditions which are usually indicated locally).
It has bean concluded that the above cited monitoring, augmented by the periodic test and surveillance requirements included in the Technical Spec i f ic at ions, provide reasonable assurance that the Clasc1E direct current power system is ready to perform its intened safety function.
i At the Callaway - Wolf Creek plants the following iocal and control room
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instrumentation, based on the FSAR, is provided for the 125 volt direct current systems to monitor status of the batteries, distribution system, and the battery chargers to absure the continual operability of the Class lE direct current power system.
5 Direct Current Instrumentation Control Battery Instrumentation Panel Room Battery current (ammeter-charge)
+
w Battery curreat (ammeter-discharge)
X X
Battery hiqh Jischarge rate alarrr Battery fu w open alatm X
X Distribution System Instrumentation 1
I Direct current bus voltage (voltmeter)
X X
Direct current bus undervoltage (alarm)
X X
Direct current bus overvoltage (alarm)
X X
Direct current bus ground alarm X
X Battery Charger Instrumentation Battery charger output current (ammeter)
X X
Battery charger output voltage (voltmeter)
X Battery charger output breaker open alarm X
X Battery charger trouble alarm X
X i
1
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10 We reviewed the monitoring provided at Callaway - Wolf Creek and concluded that monitoring instruments and alarms called for by the above cited guidelines have not been provided in the control room. The additional instrumentation required is as follows:
(1) Battery charger output voltage (voltmeter)
(2) Battery current (ammeter charger), and (3) Battery high discharge rate alarm It is our position that the above cited instruments and alarms must be provided i~n the control room. Justify your noncompliance with our position.
13.Section 8.3.2.2.1 of the FSAR does not address physical independence in accor-dance with Regulatory Guide 1.75. Describe the d-c system degree of compliance to Regulatory Guide 1.75.
- 14. Describe the seismic qualification af eyewash facilities located in the battery rooms and the protection provided causing f ailure of Class IE batteries.to preclude the eyewash f acilities from 15.Section 8.3.2.1.2 of the FSAR indicates that the initial battery capacity is 25 percent greater than required and that this margin is consistent with the battery : eplacement criterion of 80 percent rated capacity given in IEEE Standard 450-1975. Usually initial battery capacity is 50 percent greater than required due to temperature, voltage, and specific gravity fluctuation as well as the replacement criterion of 80 percent. The NRC Technical Specifications are written assuming a 50 percent greater than required capacity. Provide justification for the sizing of your batteries.
- 16. Assuming a fault on one of the offsite power trcnsmission lines and the follow-ing single failures, describe the effects, for each single f ailure, on the availability of offsite power to the Class 1E busses.
- 1) single feilure that causes loss of all switchyard primary protective relaying (such as one of the two switchyard batteries),
- 3) single failure of any one breaker to operate.2) single f ailure of pr 17.Section 5.3.3(3) of IEEE Stancard 308-1974 requires that the battery be immedi-ately available during normal operation and following the loss of power from the a-c system. Describe your compliance with this requirement.
- 16. Class lE d-c system loads are listed dif ferences of loads between subsystem 1 and 4 and between subsystem Justify your noncompliance with section 5.3.1(1) of IEEE Standard 308-1974 l
ENCLOSURE 2 SNUPPS - NRC ATTENDEES July 16, 1981 SNUPPS STAFF NRC STAFF KG&E STAFF R. L. Stright G. E. Edison S. M. Walgre, John L. Knox R. L. Robinstn G. P. Rathbun BECHTEL STAFF P. A. Ward UE STAFF Bill Ninmiller David Gasda A. C. Passwater N. P. Coel R. W. Katterhenry John S. Prebula*
Kaleem Kawaja*
M0 PSC Ronald M. Fluegge
- Part Time
gyg 131981 MEETING
SUMMARY
DISTP.IBUTION cDock$r'.ffli,~
G. Lear
'- NRC~ PDR' W. Johnston Local PDR S. Pawlicki TIC /NSIC/Tara V. Benaroya N. Hughes Z. Rosztoczy LBH Reading W. Haass H. Denton D. Muller E. Case R. Ballard
.e.s i ! v) i R. Purple D. Pass
(
D. Eisenhut W. Regan g
O{({6fl.f[A B. J. Youngblood P.Chec[-
jG'(AU 7
.\\.
Schwencer F. Cong 4
N l 7,fggy")C
)
F. Miraglia
- 0. Parr W. Butl { 4 6
F. Rosa
%* * *e J. Miller
.Q G. Lainas R. Vollmer W. Kreqe 4
J. P. Knight R. Houston t g hg R. Bosnak 7
i F. Schauer L. Rubenstein R. E. Jackson T. Speis Project Manager G. E. Edison M. Srinivasan Attorney, OELD J. Stolz M. Rushbrook S. Hanauer 0IE (3)
W. Gammill ACRS (16)
T. Murley R. Tedesco F. Schroeder D. Skovholt M. Ernst NRC
Participants:
R. Baer C. Berlinger G. E. Edison K. Kniel J. L. Knox G. Knighton A. Thadani D. Tandi J, Kramer D, Vassallo P. Collins D. Ziemann A. Ungaro bec:
Applicant & Service List R. Giardina
.-