ML20010B137
| ML20010B137 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/10/1981 |
| From: | Hukill H METROPOLITAN EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| L1L-216, NUDOCS 8108140087 | |
| Download: ML20010B137 (4) | |
Text
Metropolitan Edison Company Post Office Box 480 Ib L
Middletown, Pennsylvania 17057 Writer's Direct Dial Number August 10, 1981 L1L 216
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Mr. Darrell C. Eisenhut, Director I
4 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D.C.
20555 h i. u; 131981 *,N
Dear Sir:
\\ ~* u s., eta ncaAM comissa Three Mile Island Nuclear Station, Unit 1 (TML-1) p Operating License No. DPR-50 vv/ -
Docket No. 50-289 Status Report Plant Shielding Restart Report Section 2.1.2.3, Table 2.1-9 ccclosed, is an attachment which details the current status and some design details for the subject modificaticns listed in the restart report.
Sincerely, D.
u ill Director, TMI-l HDil: CJS : vj f Enclosure gyl$
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... Pu ohtan Edison Company is a Member of the General Pubhc Utihties System p
I ATTACHMENT The' status of the modifications tabulated in Section 2.1.2.3 Table 2.1-9 are listed below. These modifications are listed in the same order that they appear in the table.
MODIFICATION CURRENT STATUS 1.
Change operating procedures to Emergency procedures 1702-6B " Loss of require manual opening of MU-V198 Reactor Coolant / Reactor Coolant Pressure before going to recirculation (Small Break LOCA) Causing Automatic.
f rom reactor building sump (i.e.
High Pressure Injection" and 1202-6C before BWST is depleted)
" Loss of Reactor Coolant / Reactor Coolant Pressure Injection, Core Flood and Low Pressure Injection" will be revised per the commitment when Decay Heat remote valve operation capability is achieved.
2.
Install a shield wall in Area IV,
- A reinforced concrete ' shield wall has to isolate the MCC's f rom the pip-been designed and will be in place prior ing to Unit 1 Restart. The wall starts at column'line 7d, encloses the stairwell in Area'III of Figure 2.1-12, continues parallel to column line J and terminates about 9' feet from the containment wall.
Shield wall height is 12'-4".
Access aisles are maintained between the shield wall and'the piping along column line J, MCC 1A & IB and the containment outer wall. ' Wall sections in the North-South direction are 13 inches thick for direct radiation shine-attenuation and are inter-connected by a 9 inch thick East-West section.
The shield wall reduces the radiation dose rate in Area III to permit operator access post accident to reset circuit breakers in MCC 1A and/or 1B.
The reactor coolant pump seal water supply line and high pressure injection lhueB bridge the access aisle between the shield wall the containment outer wall. These lines are shielded by a 3 " thick steel plate assembly at eleva-tion 313'-0".
The plan view of the shield plate assembly is'shown in Figure 2.1-12a attached. The entire plate assembly is removeable for maintenance access to valve-operators in other overhead piping.
- 3.
Change valves DH-Vl9A & B, DH-V38A Remote Operators for DH-Vl9A & B, DH-V38A & B
& B to remote air operated with Pneumatic operators are to be retofitted air provided from bottled gas sup-to Decay Heat Exchanger outlet isolation ply good for 2 hrs. operation.
es M-M & B and Decay Heat crossover va Provide DC power for valve act-valves DH-V38A & B.
The primaiy pneumatic uation and manual loaders for posi-supply is plant instrument quality air tioning DH-Vl9A & B.
Revise with dry air cylinder back-up source. The procedure 1104-4 concerning post perators will open and close the valves, LOCA boron control so that valves m dulate DH-Vl9A & B for Decay Heat flow DH-V15A & B remain locked open control and fail as is upon loss of all and valves DH-V5A & B and DH-V6A pneumatic pressure.
& B are closed.
The back-up dry air source is a minimum of three size 1A storage cylinders located on the 281' elevation of the Auxiliary Building in Area X, reference figure 2.1-13 which is accessible post accident for cylinder replacement, if required for continued operation.
Revisions to Operating Procedure 1104-4, Decay Heat Removal System Changes to the operating procedure will be accomplished when the remote operation capability of DH-V19A & B is achieved.
4.
Change valves DH-V12A & B to Remote Operators for DH-V12A/B electric motor operated.
Electric motor operators are to be Operate DH-V64 via reach rod retrofitted to Decay Heat Suction split extension on Aux. Building,05, isolation valves DH-V12A/B. The 460V, elevation.
Extension stem is 3 phase power shall be from a Class'lE located so that operator is h m m e s s W f m "as b" protected by above noted shield upon loss of all electrical power.
wall.
Remote Operation of DH-V64 A remote manual floor stand operator for DH-V64 is located in Area IV on elevation 305', reference figure 2.1-12.
The calculated radiation dose rate in Area IV permits operator travel.and a 5 minute stay time-for valve operation no earlier than 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> after a LOCA The total accumulated dose rate for this operation is less than 3 rem.
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l PLAN VIEW i
REMOVEABLE STEEL SHIELD ASSEMBLY ELEVATION 313'-0"-AREA III AUXILIARY BUILDING Figure 2.1-l'..
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