ML20076C051
| ML20076C051 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 08/15/1983 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 23767, 82-07-#6, 82-7-#6, MCAR-59, NUDOCS 8308220196 | |
| Download: ML20076C051 (10) | |
Text
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C0mpany vi ~ u~ - er i<<. e zi <ri s and Construction General offices: 1945 West Pernell Road, Jackson, MI 49201 *(517) 788 0453 August 15, 1983 82-07 #6 Mr J G Keppler, Regional Administrator US Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND NUCLEAR C0 GENERATION PLANT -
DOCKET NOS 50-329 AND 50-330 Q-RELATED EQUIPMENT COOLED BY NON-Q HVAC SYSTEM FILE:
0.4.9.63 SERIAL:
23767
References:
J W Cook letters to J G Keppler, same subject:
(1) Serial 17529, dated June 25, 1982 (2) Serial 17578, dated August 17, 1982 (3) Serial 19096, dated November 22, 1982 (4) Serial 20696, dated February 9, 1983 (5) Serial 22187, dated May 17, 1983 This letter, as were the referenced letters, is an interim 50.55(e) report on Q-related equipment cooled by non-Q HVAC systems.
Another report, either interim or final, will be sent on or before November 15, 1983.
WRB/cd
Attachment:
'MCAR-59. Interim Report 6, dated July 25, 1983 CC: Document Control Desk, NRC Washington, DC RJCook, NRC Resident Inspector Midland Nuclear Plant 8308220196 B30815
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PDR ADOCK 05000329 S
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OC0883-0010A-MP01 I i zea7
2 Serial 23767 82-07 #6 CC: CBechhoefer, ASLB Panel LBernabei, GAP FPCowan, ASLB Panel JHarbour, ASLB Panel AS&L Appeal Panel MMCherry, Esq MSinclair BStamiris CRStephens, USNRC WDPaton, Esq, USNRC FJKelley, Esq Attorney General SHFreeman, Esq Asst Attorney General WHMarshall GJMerritt, Esq, TNK&J INPO Records Center OC0883-0010A-MP01
Bechtel Associates Professional Corporation l23ll0 l23286
SUBJECT:
MCAR 59 (issued May 28, 1982)
INTERIM REPORT 6 DATE:
July 25, 1983 PROJECT:
Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 Description of Deficiency Review of Q-related structures of the plant has been completed and indicates that only portions of the auxiliary building and service water intake structure have safety-related devices that are cooled by l
non-Q testing, ventilating, and air-conditioning (KVAC) systems. Loss of these non-Q NVAC systems following various design basis accidents (DBAs) could result in room environmental temperatures that could exceed the specified design temperature of 104F. Under these conditions, the safety-related equipment in these rooms may not operate reliably, and both trains of redundant Q-listed equipment are i
l affected by loss of the non-Q HVAC system in many instances.
Summary of Investlantion and Historical Backaround The initial review of project drawings identified a potential for 2,000 items of Q equipment in 101 areas of the auxiliary building that are cooled by non-Q HVAC systems. Subsequent detailed reviews have reduced this quantity to 1,567 items of Q equipment, of which 558 are 6
I Seismic Category I devices with no Class IE components.
The detailed reviews have also identified an area in the service water pump structure with 23 items cf Class 1E equipment cooled by non-Q HVAC systems.
This results in a total of 1,032 items of Class IE equipment cooled by non-Q NVAC systems in 57 areas of the auxiliary and service water buildings.
The reduction in the number of Class 1E devices is a result of detailed reviews that have identified devices previously considered Class IE as Seismic Category I devices with no Class 1E components.
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Bechtel Associates Professional Corporation 123l10 123286,c,,,,
Interim Report 6 July 25, 1983 Page 2 Analysis of Safety Impilcation The predicted steady-state maximum environmental room temperatures in the existing non-Q-cooled portions of the auxiliary building and service water intake structure, assuming a DBA simultaneous with an extended loss of the non-Q HVAC systems, has been determined. The resulting temperatures are based on two accident conditions as follows:
Case 1 - A loss-of-coolant accident (LOCA) in both reactor units concurrent with a loss of offsite power - All safety-related equipment has been assumed to be operating and generating heat as well as any de or diesel-backed ac nonsafety-related equipment. The auxiliary building and service water intake structure non-Q HVAC system, as well as non-Q heat sources (except as noted above), are assumed to be inoperative, whereas four trains of the safeguards HVAC system are assumed to be available.
(See Note, Page 3.)
No credit is taken for the non-Q HVAC systems after the offsite power is restored.
Case 2 - A LOCA in both reactor units with offsite power available - A total loss of non-Q HVAC systems is assumed, whereas four trains of the safeguards HVAC system are assumed to be available. Because offsite power is available, nonessential equipment could be available and generating heat as well as any de or diesel-backed ac equipment (see Note). No credit is taken for the operation of ac2-Q HVAC systems.
Peak temperature calculations were revised to account for 10 new safety-related unit coolers. The following is a summary of the results based on these revised calculations:
Case 1 Case 2 Total number of non-Q-cooled areas analyzed 173 173 Total number of the 173 non-Q-cooled areas 57 37 containing Class lE devices jb(
Total number of the 57 non-Q-cooled areas 30 47 containing Class lE devices with peak temperature 1104F Ol93u
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Bechtel Associates Professional Corporation 123110 1232pcj,,,
Interim Report 6 July 25, 1983 Fase 3 Case 1 Case 2 Total number of the above non-Q-cooled 4
4 areas containing Class 1E devices with peak temperature of 1104F and to which Q cooling will be added Remainder of non-Q-cooled areas containing 26(2) 43(3)
Class IE devices with peak temperature of 1104F and not presently planned to be Q cooled Note: Although this is not a design basis for the plant, both units were assumed to be affected by a LOCA to simplify the analysis. This assumption is conservative. Assuming one unit in LOCA and one unit in hot shutdown, the major difference would be the pipeways, where heat loads would be lower during hot shutdown because fewer engineered safety features (ESP) piping systems would be operating.
(1)
Deleted (2)
Of these 26 areas, the peak temperatures are broken down as follows:
a) 104F < 9 areas 1 110F l
b) 110F < 8 areas 1 120F c) 120F < 7 areas 1 130F d) 130F < 1 area i 140 e) 140F < 1 area i 170 (3)
Of these 43 areas, the peak temperatures are broken down as follows:
a) 104F < 10 areas 1 110F b) 110F < 10 areas s 120F t
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Bechtel Associates Professional Corporation 123286 123l10 BCAR 59 Interim Report 6 July 25, 1983 Page 4 c) 120F < 7 areas i 130F d) 130F < 7 areas 1 140F e) 140F < 3 areas 1 150F f) 150F < 1 area i 160F j \\
g) 16CF < 1 area 1 170F h) 170 < 2 areas 1 180 i
i) 180F < 1 area 1 190F j) 200F < 1 area < 210F The heat loads generated by the auxiliary building and service water intake structure electrical cables are being evaluated. The steady-state (peak) temperature calculations will be revised, if necessary, after the evaluation is complete.
Probable Cause The root cause of the discrepancies is as follows. Although documentation existed on project identifying areas served by the safety-grade ventilation system, the required interdiscipline coordination was not effective because the limiting conditions defining the maximum temperature that would be experienced by safety-related devices located in areas served by non-? HVAC systems had not been established.
Therefore, design decisions as to suitable locations for intended service were made without adequate consideration of the impact of a loss of offsite power or post-DBA conditions. This resulted in a lack of consistency in:
1.
Locating safety-grade equipment in an area served by a nonsafety-grade ventilation system 2.
Specifying and ascertaining that adequate environmental qualification service conditions exist for the safety-grade equipment when located in an area served by nonsafety-grade ventilation systems 0193u
Bechtel Associates Professional Corporation i 23286 l23Il0 BCAR 59 Interim Report 6 July 25, 1983 Page 5 Corrective Action 1.
Project engineering is still reviewing the safety function of i
Class 1E devices in the areas already identified to evaluate the safety-related implications of the equipment failure following the DBAs. Should the evaluation indicate that failure of the equipment could adversely affect the capability of the plant systems to mitigate the consequences of the accident or to achieve and maintain a safe shutdown, corrective action would be implemented on a case-by-case basis. These actions could include the following:
a)
Upgrade selected auxiliar3 building and service water intake structure HVAC systems to Q status to limit the effect of the peak room temperature within the current environmental qualification envelope of the equipment.
b)
Relocate the Class 1E device to another area where the predicted peak environmental temperature is within the l
environmental qualification envelope of the equipment.
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c)
Replace the class 1E device that does not qualify for the l
predicted peak room temperature with one that qualifies.
d)
Demonstrate that the existing Class 1E device will function as required for temperatures greater than or equal to the calculated peak room environmental temperature, specific area-by-area resolutions will be addressed in future interim reports. Case 1 results will be used as the basis for l
determining the need for corrective action. Bechtel will devalop information for Consumers Power Company's use in developing emergency operating guidance to ensure that nonessential i
heat-producing equipment will be deenergized as needed after a DBA to preclude the possibility of Case 2 occurring and to limit the peak temperatures to acceptable levels.
A computer list of the affected safety-related devices in the.
auxiliary building and service water intake structure, derived from the licensing equipment qualification data base; has been developed. The list is categorized by room number and contains information on the required operability period of the safety-related device, predicted peak temperature for Caser 1 and 2, and the proposed resolution for corrective action, if any.
This list will be used as an attachment to a report documenting the results of equipment evaluation.
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Bechtel Associates Professional Corporation I.23286 123110 BCAR 59 Interim Report 6 July 25, 1983 Page 6 After accounting for 1) the four areas in which Q cooling will be added, and 2) devices that are located in non-Q-cooled areas but l
that have been determined to be potentially qualified for the environment in which they are located, approximately 60 devices remain to be evaluated for their non-Q-cooled mild environment.
Approximately 180 devices are included in harsh environment qualification programs that require evaluation and updating to A
i address a loss of non-Q-listed ventilation. This effort will be
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finalized after the effects of electrical cable heat loads are evaluated. The basis for evaluating the acceptability of a safety-related devices' location with respect to its environmental qualification is being developed. The issues of harsh versus mild environment, operability period, failure mode, and active versus passive function are being evaluated and considered in developing the criteria.
4 2.
Project Drawings 7220-M-560(Q), Sheets 1 through 9. Rev 0, were issued on July 26, 1982, to clarify the areas of the auxiliary building that are cooled by Q HVAC systems. Project Drawings 7220-M-560(Q), Sheets 1 through 9 were revised and additional l
Sheets 10 and 11 issued on June 24, 1983, to identify the i
calculated maximum peak temperatures that the non-Q-cooled auxiliary and service water building areas will experience.
Sheet 11 tabulates temperatures calculated to date for information to project engineering. Additional considerations
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remaining to be incorporated in the calculations include recently defined increases in main control room heat loads, impact of cable heat loads, and additional related heat sources. Upon revision to the calculations for all presently identified l
considerations, this tabulation will be revised as necessary and issued for use. This effort is scheduled for completion by l
January 10, 1984. The use of these drawings should result in i
locating Q devices only in areas where a suitable environment exists.
3.
Based on preliminary evaluation, safety-grade HVAC will be added to the following four areas:
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.g Bechtel Associates Professional Corporation j
i il 2 3 2 8 6 l23Ii0 MCA: av Interim Report 6 July 25, 198.
Page 7 i
Room Room Area Name Elevation Unit Coolers 422, 506, corridor, chiller, and access 634'-6" 1VM-118A/B,
$18 areas and 646' IVM-121A/B 423, 507 Corridor, chiller, and access 634'-6" 2VM-118A/B, 519 areas and 646' 2VM-121A/B 442A/B Access control, change, and 634'-6" 1VM-120 storage areas 443A/B Access control, change, and 634'-6" 2VM-120 storage areas It is anticipated that the safety-related devices in the remaining areas are qualified for the environment in which they are located. Efforts to document this statement are ongoing.
4.
A purchase order has been issued to Carrier Corporation, the manufacturer of the safeguards water chillers, to replace the centrifugal compressors' impeller and the low-side float valve in the economizer section to increase the capacity of the four existing safeguards water chillers from 180 to 200 tons.
5.
project engineering procedure (PEP) 4.25.1 was revised on jI(
May 25, 1983, to explicitly require coordination with the mechanical discipline of all future procurement and location of heat-producing or heat-sensitive equipment.
6.
Appropriate individuals have received training in the use of j (
project Drawing 7220-M-560(Q) (Recommended Corrective Action 2) and the requirements of the revised project engineering procedure (Recommended Corrective Action 5).
Reportability This deficiency was reported to the NRC on May 26, 1982, as potentially reportable under 10 CFR 50.55(e) by Consumers Power
- Company, i
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- Bechtel Associates Professional Corporation l23119 I2'328GCins9 Interim Report 6 July 25, 1983 Page 8 Submitted by:
$W2ndi r. P,ts &
T.G. Ballweg Mechanical Group Supervisor Approved by: 4 $k
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N.H.Hughesh Pr t Engineer Concurrenceby:/
%it.T. Fravel ChiefMechanhal Engineer Concurrence by:
4 E.H. Smith Engineering Manager b l%
fu Concurrence by:
M. A. Dietriell/
Project Qual.Ity Assurance Engineer NOTE: A Denotes information that has been revised or that is new since the last interim report.
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