ML19317E904
| ML19317E904 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/30/1974 |
| From: | Grier B US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Jennifer Davis US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001070704 | |
| Download: ML19317E904 (4) | |
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i AUG 3 01974 1
i J. G. Davis, Deputy Director for Field Operations f
DUKE POWEk COMPANY (OCONEE 1) DOCEET NO. 50-269 - EVAL LICENSEE'S RESPONSE TO ENFORCEMENT CORRESPONDENCE Duke Power Company's response to.the Region 11 enforcement letter was evaluated relative to two Oconee 1 violations 12, 1974 In addition, a discussion dated July in accordance with Action Request F0:95Hl.
of the subject was held with L. McDonough, the Licensing Project Manager for Oconee.
50-269/74-4) involved the operation Violation 1.A.1.a (RO Report No.
of the reactor with as many as six individual asymmetric rod monitors licensee was cited for making a change turned off. - Specifically the
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which involved an unreviewed safety question without AEC authorization.
Dcke admits that the six rod monitors were disconnected, but does not I
consider this to be an unreviewed safety question.
The It seems clear that the matter doea involve a safety question.
rod monitors are intended to provide a signal to the integrated control system (ICS, combined reactor, steam generator and feedwater control)
The when a rod becomes displaced with respect to the rest of its bank.
resulting action includes:
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- l. An Alarm i
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- 2. Blockage of rod withdrawal
- 3. Initiation of a power runback.
~Among other things, this action is intended to prevent adverse consequences from a rod drop accident as shown by Section 14.1.2.7 of the FSAR which The main concern is clearly identifidd in the analyzes this accident.second paragraph with the statement that, "In the pre power distribution, the return to full power might lead to localized power dcasities and heat fluxes in excess of, design limitations".
The same section states, "The protective action taken is:
I k All rod-out motion is inhibited.
- b. The steam generator load demand is run back to 60lll of rated M,
l load at 5%/sec."
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J. G. Davis AUG 3 01974 Duke contends that the question has been analyzed and that operntion without these protective actions has, in effect, received AEC approval.
The licensee refers to three documents in support of this contention.
The first is the Oconee 1 Fuel Densification Report (BAV-1387) dated January 1973 in which, it is claimed by Duke Power Company, this quastion has been analyzed. The (BAW-1387) discussion of the rod drop accident is confined to five lines, under the general category of reactivity insertion transients, which is intended to show that fuel densification in this reactor will not cause additional thermal problems which have not already been evaluated. No mention at all is made of the protective actions listed in 14.1.2.7.
'this reference (BAW-1387) is certainly not a safety analysis of the effects of disabling the rod anonitors.
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The second reference is Supplement 3 to the Occileo Safety Evaluation in which DL evaluates the above reference. Duke cinima this docunent 4
provides AEC approval for operation without rod monitors.
In this evaluation the rod drop incident is lunped in with a series of transients and a general statement is made that fuel densification will not cause thermal problems during such transients. Again, no mention is made of the rod monitors or of any assumptions regarding the protective features i
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required by 14.1.2.7.
This DL evaluation therefore, is not an approval i
to remove any protective features of the ICS, but relates only to the effect of fuel densification ou previously analyzed transients.
The last reference is to Section 7.2.3.3 of the FSAR which is quoted out of context by Duke Power Company as follows: " Failure of the iCS does, not diminish the safety of the reactor. None of the functions provided by tha ICS are required for reactor protection..."
The meaning of this statement is clarified by the previous paragraph iu the FSAR which states that "Maloparation or failure of the ICS or any of its subsystems places no autor.atic limitations on reactor operation l
because the ICS reverts to the manual mode.
The reasons for i
providing rod withdrawal inhibit and automatic runback, as required by
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l Section 14.1.2.7, are not related to failure of the ICS, but are intended to prevent a return to full power following a rod drop accident with the ICS working norum11y. Taken in this light, Section 7.2.3.3 is not contradictory to Section 14.1.2.7 and provides no justification for disabling the rod monitors.
From the foregoing, it is concluded that there was no adequate prior analyses by Duke Power Company of the effects of disabling the rod J
A nitors. In addition, it is apparent that the monitors were dis-connected without the knowledge of the atatica management and without 7
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AUG 3 01974 J. C. Davis l
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written procedures or proper review, as is shown by Duku's quotation from a meno by the Station Superintendent to his subordinates in
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criticism of the action.
I Duke's response to violation I. A.l.a also presents the results of an "that analysis made by BW af ter May 1974 to show, in their words, exceeded a I
core protection limits are notTnis acatement seems to be irrelevant to action".
(emphasis added) l syste:n the question, since, under automatic operation, the contro will always act following a rod drop, either to return the reactor to full power with the rod monitors bypassed, or to run the power In any case this back to 60% with the rod monitors in operation.
l analysis has not been submitted to AEC for approval as would beto taki required by 10 CFR 50.59 prior service.
Duke also attached a revision of Section 14.1.2.7 to their response, which is intended to show that the core protection criteria are met without the protective action required by the unrovised version.
New graphs are presented which show the behavior of total neutron and thermal power, average moderator temperature and system pressure, following a rod drop without the previous protective actions. Ho new discussions or graphs are presented, however, relating to the dropped rod power distribution, which is the contral concern of Duke has neither roquested a DL FSAR unless requescad to do so.
l evaluation of the revised safety analysis nor received any approva of it by DL.
In sumary:
- 1. The disabling of the rod monitors clearly involves a safety question previously identified in the FSAR.
- 2. The documentation referenced by Duke does not chow that the effects of disabling the rod monitors had beon analyzed prior to l
operation of the reactor with the monitors disconnected.
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- 3. No approval bss been given by AEC for operation of the reactor with the rod monitors disconnected.
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- 4. Regardless of regulatory considerations, the analyses presented in Duke's response and in their revision to Coction 14.1.2.7, do not seem to mis to provide adequate technical justification for full power operation with the rod monitors disconnected.
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' l It is recotsnanded that a letter be sent from the Deputy Director of Regulatory Operations to the licensee informing the company that the g
response is not adequate for the reasons given abovs.
We concur in the Region 11 recommmendation that Duke be informed that they do not have the authority to disconnect the protective rod monitors without prior Consnission approval.
l Since we feel that the licensee's revision of Section 14.1.7.4 is not adequately justified, we reconsnand that Duke be required to request DL approval of this change.
With regard to the discharge of waste water having a pH outside of.the required range (violation I.A.3.b, Appendix B, Technical which requires the limits to be applied to water laaving the site instead of regiring the limits to be applied to the wastewater collection We believe this satisfies the Region II concerns relative basin effluent.
to this problem.
OI fnal signed by 6
B. II. Crier B. H. Crier, Assistant Director for Construction & Operation Directorate of Regulatory Operations t.
L. McDonough, L cc:
- 11. D. Thornburg, RO C. M. Upright, RD:11
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