ML19345E395
| ML19345E395 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 04/02/1965 |
| From: | Doan R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Wall H CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| Shared Package | |
| ML19345E396 | List: |
| References | |
| NUDOCS 8101160276 | |
| Download: ML19345E395 (3) | |
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SUPPLEMENTAL FILE COPY UNITED STATES l*('i'Q'-)*l
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ATOMIC ENERGY COMMISSION J
l WASH I NGToN. D.C. 2CL45
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Doc. Room m ntnv nuca ro, Docket No. 50-155 APR 2 1965 E ""1 Suppl.
DRL Reading R6PRSB Reading Originator: JShea bec:
H, J. McAlduff, Ono Consumers Power Company Change No. 6 E. G. Case 1945 Parnell Road H. Shapar Jackson, Michigan L. Kornblith (2)
E. Trenz:n1 Attention:
Mr. H. R. Wall R. Huard Vice President G. Page P. Travelstead Gentlemen:
H. Steele C. Henderson The Consumers Power Company, by letter dated January 13, 1965, as D. Skovholt supplemented by telegrams dated March 2 and March 8,1965, has requested changes in the Technical Specifications of License No. DPR-6, dated May 1 1964, for the Big Rock Point reactor. The requested changes would permit a limited number of reactor start-ups when the present minimum require-ment of 3 counts per second (eps) and a signal-to-noise ratio of 3 to 1 on the out-of-core low-level neutron detectors cannot be satisfied.
This request has been designated Proposed Change No. 6 and has been reviewed in accordance with the provisions of Section 50.59 of the Commis-sion's regulations. We have found that the proposed change as supplemented does not present significant hazards considerations not described or implicit in the hazards summary report and there is resconable assurance that the health and safety of the public will not be endangered. A copy of the related safety analysis is enclosed.
Accordingly, pursuant to Section 50.59,10 CFR 50, the Technical Specifi-cations of Operating License No. DPR-6 are changed as set forth in Attachment A to this letter.
Sincerely yours, 0;igkat sig.cd LJ E. G. Case R. L. Doan, Director g
Division of Reactor Licensing i
Enclosures:
1.
Attachment A to Change No. 6 l
2.
AEC Safety Analysis R&PRSB:RL OGC R&PRSB:RL Rt kL EGCase' R1hoan' 3l30 65
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ATTACHMENT A CWSUMERS POWER COMPANY CHANGES TO TECHNICAL SPECIFICATIWS CHANGE NO. 6 1.
Section 7.3.2(d) is changed to add a new paragraph to read:
"In the event that the antimony-beryllium source strength is insufficient to produce a count rate of 3 counts per second (cps) and a signal-to-noise ratio of 3 to 1 on the out-of-core low-level neutron detectors, the approach to criticality for the reactor start-up following the September 18, 1964 shutdown and such additional start-ups as may be necessary until sufficient power operation has been accumulated to irradiate the antimony pins to acceptable levels (but not to exceed 3 months from first start-up) shall be allowed with the count rate from the two out-of-core low-level neutron detectors less than 3 cps and the signri-to-noise ratio-less than 3 to 1 provided that the following conditions t.re met:
Critical approaches with the reactor vessel head-off shall be a.
performed to evaluate the out-of-vessel low-level detector response, apecial low-level miniature in-core detector response and t! e control rod withdrawal sequences. Two additional low-level detectors shall be temporarily inserted in the vessel to monitor these head-of f critical approaches and these detectors nust satisfy the minimum requirement of 3 cps with a 3 to 1 signal-to-noise ratio with all rods in.
b.
The intervals between the step (notch) control rod withdrawals shall be restricted to permit continuous plotting and evaluation of control rod position, k gg and detector signals, (a minimum e
of threo miniature in-core fission counters, two temporary in-core low neutron level detectors, and all out-of-core detectors) vs. time until r.Titicality is -achieve d and the CIC picoammeters respond.
Evaluation of instrument responses during the head-off critical approaches shall demonstra:e that-by-the time the estimated k gg e
of the core reaches 0.990 either (1) the low-level out-of-core start-up detectors are reading at least 3 cps with a 3 to 1 signal-to-noise ratio or (2) the two special low-level in-core miniature detectors are responding to changes in k gg and are reading at least e
10 cps.
j c.
Critical approaches with the head on and without the temporary I
in-vessel low-level detectors in service shall be permitted pro-vided that:
l (1) The instrument response requirements of b. above have been denenstrated and these requirements are also ex-pected to be met during the critical approaches with the head on.
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r (2) The sequence of control rod withdrawal is identical to the sequence of rod withdrawal analyzed to be safe and used during the previous approaches to criticality with the head off.
(3) The rate of control rod withdrawal is no faster than with-drawal rates used during ' head-off' tests.
(4) Rod positions, k gg and all nuclear signals are manually e
recorded or plotted against titue and evaluated against the
' head-off' performance. Deviations from expected behavior during the start-up which could cauce nuclear uncertainties shall require an insnediate manual set tm of all control rods, d.
The procedures in a. and b. above shall be repeated in the event either a core configuration change or a significant change in the control rod withdrawal sequence is employed.
A qualified reactor engineer shall be in the control room during e.
all low source level start-up operations overseeing the start-up orarations."
2.
Section 7.3.2(e) is revised in its entirety to read:
" Critical approaches shall be monitored using low-level neutron detectors.
The start-up rate shall be restricted to demonstrate that the CIC picoammeters overlap of low-level neutron detectors signals for at least one decade starting at about 10-5, indicated full power on the picoammeters is normal 7
and satisfactory for control and safety purposes before continuing further into the power range. Control rod withdrawal sequence shall be specified and limited to those sequences shown by previous analysis or tests to preserve fuel integrity in the event of accidental reactivity insertion either while starting up or at power."
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