ML18043A967
| ML18043A967 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/20/1979 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7908230473 | |
| Download: ML18043A967 (7) | |
Text
consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201 * (517) 788-0550 August 20, 1979 Director, Nuclear Reactor Regulation Att Mr Dennis L Ziemann, Chief Operating Reactors Branch No 2 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - TECHNICAL SPECIFICATIONS CHANGE RELATED TO H2 RECOMBINER UNIT.S..
References:
(1).Letter From DP Hoffman to A Schwencer Dated September 19, 1977 (2)
- Letter From GS Cashell to RD Silver Dated September 21, 1978 (3)
Westinghouse Recommendations Dated September 13, 1978 and July 5, 1979 (Enciosures 1 and 2, Respectively)"
Attached are three (3) original and thirty-seven (37) conformed copies of a*
request for a change to the Palisades Technical Specifications.
During the operation and testing of Westinghouse hydrogen recombiners at the Palisades Plant, a situation which.can lead to an incorrect conclusion with respect to unit operability was experienced.
In Ref~rence (1), we proposed a method to eliminate this problem.
Reference (2) withdrew that proposal pending receipt of information from Westinghouse, Reference (3), who supplied the H2 r~combiner units.
This proposed change incorporates the Westinghouse recommendations.
It involves a single safety issue.
Therefore, a check in the amount of $4,000 is attached pursuant to 10 CFR 170.22, Class III change.
David P Hoffman Assistant Nuclear Licensing Administrator CC JGKeppler, USNRC
CONSUMERS POWER COMPANY Docket 50-255 Request for Change to the Technical Specifications License DPR-20 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in Provisional Operating License DPR-20, Docket 50-255, issued to Consumers Power Company on October 16, 1972, be changed as described in Section I below.
I.
Changes Change Item 12 of Table 4.2.2 to read as follows:
"12.
Hydrogen Recombiners Each hydrogen recombiner unit shall be demonstrated operable:
- a.
At least once per 6 months by verifying during a reeombiner unit functional test that heater sheath temperature increases to ~ 700°F within 90 minutes.
Upon reaching 700°F, increase power setting to maximum power for 2 minutes.
Verify that the power meter reads.2: 60 kW.
- b.
At least once per 18 months by:
II.
Discussion
- 1.
Performing a channel calibration of all recombiner instrumentation and control circuits.
- 2.
Verifying through external visual examination that there is no evidence of abnormal conditions at the recombiner enclosure (ie, dents, deposits, etc).
- 3.
Verifying the integrity of the heater electrical circuits by performing continuity checks."
Presently there are two items (12.a and 12.b.4 of Table 4.2.2) concerning the output of the heating units.
The specification requiring the units to reach 700°F within 90 minutes has little usefulness by itself in determining the operability of the units.
We experienced a 1
situation in which one phase of the three-phase power supply for one unit was shorted to neutral.
The remaining two phases (with the shorted phase cleared by a fuse) produced enough heat to easily meet the 700°F criteria.
Considering the fact that recombination occurs in the neighborhood of 1150°F and that the unit (with one phase shorted) was incapable of reaching il50°F, this specification is misleading when used as the only check of unit operability.
For these reasons, it is proposed that all electrical phases be demonstrated operational by increasing the recombiner to maximum power setting for a short period of time and verifying that full power is achieved.
If a single phase is nonoperating, maximum power will be reduced by one third.
The existing Item 12.b.l of Table 4.2.2 is inappropriate since the bus alignment is a function of plant design and breaker selection.* Also, the diesels are not used as the source during the testing.
The o~iginal Ite~ 12.b.3 of Table 4.2.2 requires a visual inspection of the interior of the heating enclosures.
However, if this is interpreted to mean that an inspection of the heater banks is to be performed, the entire structure must be dismantled and it is not designed for a routine operation of this nature.
Such disassembly always introduces the possibility of rendering the unit less reliable than it was prior to the evaluation.
In addition, since there are no moving parts, it is difficult to see how such an examination could possibly yield as much information as a simple external visual examination coupled with an electrical resistance check.
For these reasons, the specification is changed to a simple visual check.
2
The original Item 12.b.5 of Table 4.2.2 requires the electrical check to be performed after the heatup test.
This is unnecessary since our intent is to check for shorts and not variation in resistance values to ground.
(See Enclosure 1 dated September 13, 1978.
Thus, this requirement should be amended as in the proposed specification.
III.
Conclusion Based on the foregoing, both the Palisades Plant Review Committee and the Safety and Audit Review Board have reviewed these changes and find them acceptable.
CONSUMERS POWER COMPANY By~h D~wm R B DeWitt, Vice President Nuclear Operations Sworn and subscribed to. before me this 20th day of August 1979.
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~~inqa,~J< Carstens, Notary Public J;:i_ckson County, Michigan
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My ~omro:l~pion expires June 10, 1981.
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Table 4.2.2 (Continued)
Minimum Frequencies for Equipment Tests
- 12.
Hydrogen Recombiners Each Hydrogen Recombiner unit shall be demonstrated operable:
- a.
At least once per 6 months by verifying during a recombiner unit functional test that heater sheath temperature increases to ~ 700°F*
within 90 minutes.
Upon reaching 700°F, increase power setting to maximum power f~r 2 minutes.
Verify that the power meter reads i 60 kW.
- b.
At least once per 18 months by:
- 1.
Performing a channel calibration of all recombiner instrumentation and control circuits.
- 2.
Verifying through external visual examination that there is no evidence of abnormal conditions at the recombiner enclosure (ie, dents, deposits, etc).
- 3.
Verifying the integrity of the heater electrical circuits by performing continuity checks.
- As measured by installed or portable temperature measuring instruments.
4-lSa
ENCLOSURE 1 y "
~ECE*VED Slt-i l ~ 1978 LICENSl"-1!-
Westinghouse Electric Corporation Power Systems PWR Systems Divisi!Jl Box355 Mr. G. S. Cashell
. Nuclear Licensing Analyst Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201
Dear Mr. Cashell:
PlttsllJrgh Pennsylvania 15230 September 13, 1978 The following is in response to your letter requesting Westinghouse review of the proposed Technical Specification changes for the Electric Hydrogen Recombiner.
The proposed increase in test temperature from 700°F to 1200°F in 12.a will demonstrate that the units are operable as stated in the discussion, however the qualified life of the recombiner (40 years) is based on a test of 80 heatup and cooldown cycles between ~1200°F and ambient temperature.
The proposed change in heatup temperature does use up most of the demonstrated qualified life.
We suggest the same end re-sult of demonstrating that all.electrical phases are operational could be obtained by increasing the recombiner to maximum power setting for a short length of time and verifying that full power is achieved. If a single phase is non-operating, maximum power will be reduced by one-third.
We suggest the following change in 12.a:
"At least once per 6 month by verifying during a recombiner unit functional test that heater sheath temperature increase to ?700°F within 90 minutes and is maintained fo~ at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
At the end of the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> test, increase power set-
. ting to maximum power for 2 minutes. Verify that the cower meter reads ?60 Kw.
With regard to 12.b.l and 12.b.3, Westinghouse agrees with your reasoning on these items.
With regard to 12.b.5, the reason the resistance checks were originally specified for immediately after the heatup test is that the heater resis-tance values from phase to ground vary widely depending on the moisture in the recombiner environment and the length of time the heaters are exposed to the moisture.
When the recombiner is heated up, the moisture is driven out of the heater and the heater resistance to ground increases to a more stable value.
Your proposed change is satisfactory if it is interpreted to mean that the intent is to.check for shorts and not varia-tion in resistance values to ground.
John F. Wilson Advisory Engineer
ENCLOSURE 2 Westinghouse Electric Corporation
. Power Systems PWR Systen1s Division
".)'. __ j 1979 Box 355 Pittsburgh Pennsylvania 15~~(ll G;:"' o 1 1 r_ r.i,1.~: !.._,,....
Mr. G. S. Cashell
- Nuclear Licensing Analyst*
CONSUMERS POWER COMPANY 1945 West Parnall Rd.
Jackson, Michigan 49201 July 5, 1979
SUBJECT:
ELECTRIC HYDROGEN RECOMBINERS
Dear Mr. Cashell:
As discussed in our L*'lephone conversation on July 3, 1979, we agree to the following statement being incorporated as item 12 a, table 4.2.2 in the proposed technical specification changes for the
- electric hydrogen recombiner.
11 At least once per 6 month by verifying during a recombiner unit-functional test that heater sheath temperature increase to> 7000F within 90 minutes.
Upon reaching 7000F, increase power setting to maximum power for 2 minutes.
Verify that the power meter reads ~ 60 kw.
11 cc:
R. L. Phipps P. L. Lain Fi 1 e:
EHR-9030 Very truly yours, A. 0 I 1-f ()v.c_
G. J. O'Hare Specialty Products