ML19337B593
| ML19337B593 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/26/1980 |
| From: | Janecek R COMMONWEALTH EDISON CO. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8010070394 | |
| Download: ML19337B593 (2) | |
Text
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N Commonwealth Edison
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- ) One First National Pera, Chic"go, libnois t
O Address Reply to: Post Office Box 767
\\
Chicago, Ilknois 60690 September 26, 1980 Mr. Dennis M.
Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing U.S. Nuclear Regulatory Commission Washington D.C. 20555
Subject:
Dresden 1 SEP Topic V-11.A, REQUIREMENTS FOR ISOLATION OF HIGH AND LOW PRESSURE SYSTEMS NRC 00cket Nos. 50-10 Reference a):
Dennis M.
Crutchfield's July 1,1980 letter to D. L.
Peoples.
Dear Mr. Crutchfield:
Commonwealth Edison while noting the two MOV's referenced in Section 3.1 are normally closed valves, concurs with the factual in:'ormation in the above referenced report.
However, based on the criteria presented it is believed the conclusion of the report is incorrect.
Section 2.2 of the report in part states:
"2.2 Emergency Core Cooling System.
Isolation requirements for ECCS are contained in SRP 6.3. Isolation of ECCS to prevent overpressurization must meet one of the following features:
(1)
One or more check valves in series with a normally-closed motor-operated valve (MOV) which is to be opened upon receipt of a SIS when RCS pressure is less than the ECCS design pressure."
Section 3.1 states, in part:
"3.1 Core Spray System.
The CS system consists of three pumps providing water to a single header via two parallel piping branches.
Isolaton of the two branches is provided by two MOVs in series with a check valve in-each branch.
"The MOVs open upon receipt of a CS system start signal when the RCS pressure has decreased to within the CS system design pressure (determined by AP indicator)..."-
The conclusion of section 3.1.
states:
"The CS system does not meet current licensing requirements for isolation of high and low pressure systems, contained in SRP 6.3, since there areono interlock 3 to prevent the operator from opening the solation valves when ItCS pressure exceeds system design pressure."
8010070;3cysg
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.y 4,
A Commonwealth Edison g.
I The conclusion should be that Dresden 1 complies with the current licensing criteria as centained in SRP 6.3.
This conclusion is based on the criteria set forth in the evaluation and the factual description of the Core Spray System which is correct except for not noting that the two MOVs are normally closed.
Interlocks ta prevent the operators from opening the CS system isolation valves from the control room or the local control station when RCS pressure exceeds CS system design pressure have not been addressed by the criteria set forth for this evaluation.
Therefore, the Core Spray System should not be judged against such criteria.
Please address any questions you may have concerning this matter to this office.
One (1) signed original and thirty-nine (39) copies of this transmittal have been provided for your use.
Yours very truly, 44tr)-a Robert F.
Janecek Nuclear Licensing Administrator Boiling Water Reactors NPS:mnh 6810A