ML19210B208
| ML19210B208 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/16/1976 |
| From: | Baer R Office of Nuclear Reactor Regulation |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7911040137 | |
| Download: ML19210B208 (2) | |
Text
_
e
'e r-
- 4 8P' e49 MAR 161976 go 2 8 7 l
Albert Schwencer, Chief j
Plant Systems Branch, 00R THREE MILE ISLRID t#1IT 1 ECCS A'IALYSIS The Reactor Safety Granch is reviewing the Three Mile Island-Unit 1 ECCS analysis for compliance with 10 CFR 50.46. The following valves have been identified as requiring review for electrical independence, interlocks, and the effects of submergence.
I.
Submerged Valves Safety MU-V2A.B Letdown cooler containment isolation 1
IC-Y2 Intemediate cooler containment isolation Non-s afety_
IC-V1A,B Letdown cooler shell side inlet isolati.on IC-Y20 RC drain tank cooler outlet isolation
' WDL-V302 Letdown cooler tube side inlet isolation MU-VIA.B RC Tank recirculation WDL-V305 RC Tank recirculation l
It should be noted that the two safety grade valves above will have perfomed their intended containment isolation function prior to submergence.
II.
Electrical Independence MU-Y14A&B Pump suction MU-V16A&B,C&D Pump discharge i
DH-V4A&B Decay heat cooler outlet DH-VSA&B BWST isolation
~~~
l Dil-Y6A&B Sug isolation The above valves should be examined to detemine whether or not a single fault can prevent the operation of redundant trains.
15;7 23 7911040/ 3 70
or es MAR 161976 i
l A. Schwencer 1 t
i In addition, mactor coolant valve RC-V4 and decay heat drop lino valves Di-V1, 2, and 3 must be reviewed to detennine whether or not a single i
fault can prevent at least one flow path from being available for long term boron control. Minimum requirements are that either RC-V4 i
be operable or Di-V1.2.and 3 be operable.
Interlocks III.
i i
W V1 ~
Decay heat drop line W-V2 Decay heat drop line The above valves should be reviewed to insure that they have the proper interlocks to prevent opening while the reactor coolant system is pressurized. Such an event could result in a LOCA outside the l
containment.
Metropolitan Edison has supplied electrical drawings and schematics.
The drawings will be provided to the electrical reviewer as soon as one l
is appointed.
' Robert L. Baer. Chief Reactor Safety Branch I
Division of Operating Reactors t
CC:
V. Stello k and DISTRIBUTION MMIMa1XR118 Docket Files (50-289)
NRR Rdg.
I RSB Rdg.
I RLandry l
)5)
OR:RSB 0Rg, B o,,,c.
- c
.RB ae r
.u. m.
3//g/76 3/ lle/.76 _
..r.
- u. s. eovannasant rainvine orrics: tova.ssa.see Foran AEC-)IS (Rev. 9 $3) AECM 0240 9