ML19319B045
| ML19319B045 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/29/1970 |
| From: | Pollard R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19319B039 | List: |
| References | |
| NUDOCS 8001070539 | |
| Download: ML19319B045 (5) | |
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t-UNITED STATES I
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[3A.Hore,, Chief,ElectricalSystemsBranch,DRS 711cs V
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i STATUS OF THE OCONEE NUCLEAll STATION POL REVIEU; DOCKET NOS. 50-269,
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-270 AND -287 I am presently writing the Electrical Systems Branch portion of t.he report to the ACRS on the Oconce Nuclear Station.
I believe, however, that the u.ncertain schedule for review of the.0conce POL applications by the ACRS together with my forthcoming transfer indicates a need to i
report separately on the status of my review.
g Enclosed is a list of all those items which I consider require addi-l tional action as of this date. It is es:pected that most of those items will be resolved by the applicant's responses to outstanding questions. Other items are the result of inadequate responses to questions and additional information is needed to resolve these.
Finally, there are three items which we consider as unresolved and will be reported as such in my report.
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R. D. Pollard ESB-52 Electrical Systems 3rnnch DRS:ESB:RDP Division of, Reactor., Standards
Enclosure:
As stated above cc w/ encl:
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E. G. Case, DRS R. c. DeYoung, DRL C. G. Long, DRL.
A. Schwencer, DRL J*
-O. D. Parr, DRL.
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OCONEE POL APPLICATION
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Questions Uhich Lack Acceptable Answers E
1.
Question 6.3 requested the applicant to describe the qualification tests which have been or will'bc performed on equipment which is I
required to be operabic during an accident. The response did not i
descrjibe the tests and did not discuss whether the tests are planned or completed. We need a brief description of the tests and a state-g ment that each items has satTs'factorily passed the test or a state-e ment that t$he test will be satisfactorily completed prior to the
.ACRS meeting. Of particular concern are,the sensors which provide
= =,i reactor trip cignal: er which actuate the engineared safety feature systems.
2.
Question 7.3 has been partially answered; part (e) was not specifically
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addressed. At this late date in the operating 11 cense review, I believe that we can complete our report without the information, however; the applicant should be requ.c.sted to respon '.c 'he
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question.
3..
The response to Question 7.15 states that the rod program =er motors are powered from a source whose frequency is locked to the plant's a-c power frequency., Sinca at least part of the rod control system's f
power is from inverters, we need to see a ; - ry of a failure mode I
analysis to show that the frequency variations produced by the
' inverter are-limited to an acceptable value.
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In Question 7.21, we expressed our concerns with the reactor coolant flow sensing scheme. The response addresses the rupture
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of any common sensing line but this is only one possible failure mode. The concern remains that other singic failures (e.g.,
blockage of any one line) may prevent all flow instruments in one loop from responding to flow changes. We need to see a summary of a system analysis to cover any singic failure.
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The response to Question 14.3.2 is not adequate. The fact that two channels are provided does not in itself assere that the system
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i meets the requirements of IEEE 279. We need to know whether the system is designed in accordance with IE.EE 279 and, in particular, i
the cxtcnt to which the periodic ~~~*-
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circuitry duplicates the operation required under accident conditions.
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6.
Th'e following questions have not been answered; depending on the responses, review of the schematics for the systems concerned may be required:
14.3.3 - All or part of the Integrated Control System 14.3.9 - Steam generator water level 14.4.1 - Pressurizer level j
~14.4.2 - Pressurizer level and heater control 7.
A question concerning the design of the onsite power distribution
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system was fonrarded to DRL with our letter, ESB-26, dated May 15, 1970.
I understand that tihis question.has be'e[ informally transmitted
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1 to the applicant and that a formal response will be submitted.
This response should be reviewed by the ESB to determine if the present design is acceptable for the Oconce units.
Unresolved Items 1.
In our letter (ESB-26) to DRI., we discussed two items on which vc were unabic to reach agreement with the applicant:
(1) Operation with 1 css than four reactor coolant pumps in service, and (2) automatic transfer of power 4to redundant 600 volt engineered
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safety feature buses.
Based on the ACRS com=ents on Indian Point Unit 2, we will want to re-evaluate our position regarding the manual set point adjustments proposed by Duke. Regarding the automatic transfer feature, our report should reflect ourrecom-mended position that it be eliminated.
2.
Dr. Morris' letter of February 13, 1970, to the applicant clearly stated our position that all functions required for effective emergency core cooling should be actuated from the sensing of diverse variables. The applicant's position, stated in the response to Que'stion 7.22, is that a diverse reactor trip signal is not necessary because the low p'rcssure trip is reliable.
I believe that our position remains the same and that this item will be resolved.during the ACRS review.
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