ML20010J459
| ML20010J459 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/29/1981 |
| From: | Hukill H METROPOLITAN EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| L1L-269, NUDOCS 8110050117 | |
| Download: ML20010J459 (4) | |
Text
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Metropolitan Edison Company N
Post Office Box 480 Middletown, Pennsylvania 17057 Writer's Direct Dial Number September 29, 1981
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Office of Nuclear Reactor Regulation
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Attn:
Darrell C. Eisenhut, Director L
Division of Licensing
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,p U. S. h elear Regulatory Commission d
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7 Washington, D.C.
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Dear Sir:
' ' " "[p Three Mile Island Nuclear Station, Unit 1 (TMI-t Operating License No. DPR-50 Docket No. 50-289 Seismic Qualification of Auxiliary Feedwater System In response to your letter of February 10, 1981 concerning the " Seismic Qualificatiun of Auxiliary Feedwater Systems" the enclosed information is provided.
Please be advised that the information provided addresses only mechanical systems.
Information concerning seismic qualification of elec-trical systems is still under evaluntion and will be provided at a later date.
Results of the walkdown of the system (which was performed in conjunction with inspections in support of I&E Bulletins 79-02 and 79-14) indicated a number of deficiencies listed below (reported in LER 81-007):
Support Repair Completed EF - 8 4/7/81 EF - 72 7/27/81 EF - 125 7/31/81 i
Additionally, recirculation lines (2 inch and smaller) of the Emergency Feedwater Pumps f rom down stream of restriction orifices (i.e. FE-104, 105 and 106) to the condensate storage tank B are not designed to seismic requirements. These recirculation lines will be upgraded to Seismic Class I piping at the next refueling.
Sincerely, I
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I D. I u'cill
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Director, TMI-l
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ih 8110050117 810929 PDR ADOCK 05000289 P
PDR Metropohtan Edison Company is a Member of the General Pubhc Utihties System
1 4
Item.1 Specify whether your AFW system is (a) designed, constructed, and maintained (and included within the scope of seismic related Bulletins 79-02, 79-04, 79-14 and 80-11, and IE Information Notice 80-21), in accordance with Seismic Category I requirements (e.g., conformance to Regulatory Guides 1,29 and the applicable portions of the Standard Review Plan or comparable criteria) or (b) designed, constructed and maintained (and included within the scope of seismic related Bulletins 79-02, 79-04, 79-07, 79-14, and 80-11 and IE Information Notice 80-21) to withstand a Safe Shutdown Earthquake (SSE) utilizing the analytical, testing, evaluation methods and acceptable criteria consistent with other safety-grade systems in your plant.
To assist the staff in an expeditious assassment of your plant, if your AFW system or portions thereof, is not qualified to withstand an SSE utilizing the analytical, testing and evaluation criteria, consistent with other safety-grade systems in your plant, we request that you identify those components and structures not seismically qualified in the appropriate row of the attached Table 1.
Response
The Emergency Feedwater System at TMI-1 was evaluated and the results are summarized below:
1)
EFW Pumps and Motors - have been designed to meet seismic Class I requirements in accordance with paragraph 5.1.2.1.2 and 5.4.5 of the TMI-l FSAR (Also see Table 5-7).
2)
EFW Piping - has been designed to meet seismic Class I re-quirements in accordance with paragraph 5.4.4 and 5.4.5 of the TMI-l FSAR (Also see Table 5-7).
For additional information see TMI-l Restart Report Supp. 1 Part 2, Question 12.
3)
EFW Valves / Operators - have been designed to meet seismic Class I requirements in accordance with paragraph 5.1.2.1.2 and 5.4.5 of the TMI-1 FSAR (Also see Table 5-7).
The seismic calculations for valves associated with the EFW system indicated that during OBE the stresses in the valve are less than yield strength of the material used.
During an SSE, the stresses are always less than the ultimate strength of the material used.
Hence, the structural in-tegrity of the valves is assured during and after the SSE.
However, duc to a lack of information in the vendor's cal-culations, we cannot determine if these valves are quali-fled under SSE for functional operability during and after the earthquake.
The SSE functional operability of the valves related to the EFW system is still under internal review.
4)
EFW Power Supplies - is currently under eva]iation.
Results will be submitted at a later date.
5)
EFW Primary Water and Supp1v Path - (Condensate Storage Tank to EFW Pumps) has been designed to meet seismic Class I require-
- - = - -
ments in decordance with 5.4.4 of the TMI-1 FSAR (Also see Table 5-7) except the recirculation linea (2" and smaller) of EFW pumps from downstream of restriction orifices (i.e. FE 104, 105 and 106) to the Condensate Storage Tank B.
6)
Secondary Water and Supply Path - (River Water and Condenser Hotwell Supply to EFW System). A backup supply of river water is available ' rom the Reactor Building Emergency Cooling Pumps.
The piping from the pumps to the EFW pump common suction header is designed to Seismic Class I requirement. The seismic quali-fication of components in this system has been re-evaluated.
However, the piping was re-evaluated in response to IEB 79-02 and 79-14.
The procedure for transfer of this water source requires operator action to unlock and open valves EF-V4, 5 located in the Intermediate Building basement.
Our response to ques-l tion 10e as given in Supplement., Part 1 of the Restart Report j
indicates that plant procedure will be revised to provide guidance to the operators for use of the backup water sources.
There is no double isolation valves between the Seismic Class 1 (COV-14) water supply piping and the Non-Seismic Class 1 piping to the condenser hotwell.
Failure of either CO-V14A or B to isolate the CST from the Non-Seismic piping will allow the CST to drain to the condenser hotwell or turbine buildings. An evaluation is underway which may require an additional modification.
7)
Initiation and Control - is currently under evaluation.
Results I
will be submitted at a later date.
8)
Structures Supporting or Housine these EFW System Items are protected by the Intermediate Building which has been designed to meet Seismic Class I requirements per paragraph 5.1.2.1.1 and 5.4 of the TM1-1 FSAR. The intermediate building is designed for aircraft impact load per paragraph 5.1.3 of FSAR.
(Also see Table 5-7).
As discussed in Table 5-7 of the TMI-1 FSAR the Condensate Storage Tanks are seismically qualified.
l The Turbine Building is not seismically qualified.
9)
Supporting systems to Achieve Safety Function of EFW System:
Main Steam to Atmospheric Dump Valves and EFW Turbine:
a.
The main steam piping to the atmospheric dump valves and EFW turbine is designed to Seismic Class I requirements.
The seismic qualification of components is the same as item 3.
b.
Instrument Air Supply to the EFW System Components:
l l
The instrument air supply piping from the l
instrument Air Compressors (Tagged 1A-PlA&B) l to the valve, 1A-V27, is designed to Seismic Class I.
The air supply f rom va:ve 1A-V27 to the EFW system components is non-seismic piping.
I
The seismic qualification of components in the system has not been evaluated.
However, a Seismic Class I air supply system will be pro-vided to supply compressed air for operation of components within the Main Steam and EFW systems for a period of two hours without the availability of the plant instrument air compressors. The components to be supplied by this system are valves EF-V30A/B, EF-V8A/B/C, MS-V6, and MS-V4A/B.
Item B Where seismic qualification is indicated by leaving Table 1 blank, provide a description of the methodologies and acceptance criteria used to support your conclusion of seismic qualification, including: Seismic analyses methods employed, seismic input, load combinations which include the SSE, allowable stresses, qualification testing and engineering evaluations performed.
In addition, where seismic qualification of a secondary water supply or path is relied upon, provide a summary of the procedures which would be followed to enable you to switch from the priaary to secondary source.
Response
See Item A.
Item C If a lack of seismic qualification is indicated for items 1, 2, 3, 4, 5, and 6, 7, or 8 in Table 1, provide additional information which specifies the level of seismic qualification afforded in the original design for each of these areas.
Response
See Item A.
Item D If substantial lack of seismic qualification is indicated for items 1, 2, 3, 4, 5 and 6, 7, or 8 in Table 1, provide the same information requested in A through C for any alternate decay heat removal system. The bounds o f these systems shall be considered to a similar extent as that described for the AFW system.
Provide a summary of the procedures by which operation of these alternate heat removal systems will be accomplished.
l
Response
See Item A.
l l
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