ML19329G106

Affidavit Addressing Issue of Hydrogen Generation & Control Following Postulated TMI-type Accident.Action Implemented Effectively Precludes Excess Hydrogen Generation

ML19329G106
Person / Time
Site:	Mcguire, McGuire
Issue date:	07/09/1979
From:	Canady K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML19329G103	List: ML19329G102 ML19329G106 ML19329G110
References
NUDOCS 8007140007
Download: ML19329G106 (5)

Text

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UNITED STATES OF AMERICA NUCIZAR REGULATORY COMMISSION .

In the Matter of. )

)

DUKE PCh'ER COMPANY ) Docket Nos 50-369

) 50-370 (Willian B. McGuire. Nuclear-

) .

. Station, Unita 1 and 2) ) - - ' ' -'

. . j AFFIDAVIT ~OF K. S. CANADY .

I, K. S. Canady, being first duly sworn, do depone and state: -

I am employed. by Duke Power Cc=pany in the position. of Manager of the~ project Coordination.and Licensing Section of the Stean pro-duction Department. As such.I am responsible.for coordinating-the McGuire Nuclear Station -(McGuire) licensing effort required T to satisfy both the entablished NRC regulations and.. those that have ovolved.following the accident at Three Mile.. Island Unit 2 (TMI-2)~

This Affidavit addresses the issue of hydragon generation-and control following a, postulated TMI-type accident at McGuire.

Specifically, this Affidavit demonstrates that the action implemented by Duke Power Company with respect to McGuire ef-factively precludes the./ generation.of excess hydrogen.resultinc from a TMI-?,ype accident. -

McGuiro will havet an Emergency Core Cooling System (ECCS)'.

The ECCS' for McGuire has been desi 77.ed to meet tho. low concen-

-tration limits requirod: by 10 CFR 50.44. The Enc Staff confirmed this point in its Safety Evaluation lleport, Supplement No. 2, March 1979, p. 6-4. Accordingly, operation of the ECC3

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..g as designed, will not result in the generation of substantial quantities of hydrogen (in excess nf the design basis of 10 CFR '

50.44). I With retpect to the actual operation of the ECCS in a TliI- ~

type accident, such is assured by meeting the requirements for -

the Near Term Operating License plant's set forth in NUREG-0694.

• These requirements which are addressed below, have resulted in (1) changes in McGuire a?ainistrative procedures, (2) hardware modifications of the plant, (3) increased and more comprehensive '

training programs, and (4) additional and better infoinied control room personnel. .

ADMINISTRATIVE PROCEDURES The most direct of these requirements was originally issued ~

in the NRC/OIE Bulletins which explicitly instructed the operators not to prematurely turn off the ECCS. To implement this require-ment Duke has taken the following actions to assure that the shift personnel will properly operate the ECCS:

o procedures require that the operators not terminate ECCS unless an adequate subcooling.-r.argin; is veri-fied.

e checklists for valves, power supplies, and pumps are incorporated into the procedures to assure readi-ness of the ECCS.

• shift turnover checklists are utilized to assure that oncoming operators are knowledgeable of ECCS equipment operating conditions.

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• emergency procedures involving operation of the ~

ECCS have been written or revised in accordance with the latest technological information from Westinghouse concerning TMI-type accidento.

EQUIPMENT AND INSTRUMENTATION In addition to the above procedural changes, instrt$entation F1 will be installed.at McGuire to provide additional information '

to tihe operator regarding the cooling condition of the reactor *9 core. This instrumentation includes safety-grade auxiliary

• feedwater system flow indication and the installation of..a '

reactor coolant subcooling monitor. Both provide the operator with advance warning of conditions which would lead to an in- -

adequate core cooling situation. In such a circumstance, the v~

procedures noted above will be implemented to assure that quantities of hydrogen in excess of design will not be generated.

Further, a reactor coolant system vent will be provided to vent -

from the primary coolant any non-condensible gases which could interfere with cooling the reactor core.

TRAINING To augment procedural and equipment changes, the McGuire operators have received intensive academic and si=ulator training -

in the TMI accident sequences. In addition, these operators will -

receive regular retraining in responses to accident conditions including ECCS operations. These training programs are reviewed -

and approved by the NRC staff.  :

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CONTROL ROOM PERSONNEL Additional post-TMI licensing requirements which serve to improve nuclea'r plant safety and ECCS performance include (1) a technical advisor to the shift supervise; to aid in the di~agnosis and control of transients, including ECCS operation, (2) a shift staffing change which provides for the continuous presence of a senior reactor operator in the control room, and (3) improvements to the McGuire control room which facilitate presentation of information, including ECCS equipment status,'to the operators.

In addition, the McGuire design has been podified to further reduce-the possibility of a TMI-type accident. Position indi- '

cation of the pressurizer power-operated relief valves (PORV) and pressurizer safety relief valves will be provided in the McGuire -

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control room. This indication was not available to the operators of TMI Unit 2. Furthermore, Duke has performed full scale steam flow testing of PORV and PORV block valves identical to those used at McGuire. These tests and the subsequent modifications to the valves provide additional assurance that the McGuire PORV and PORV block valves will operate as designed.

These actions which I have briefly described above, in con- 1 junction with the existing McCaire design and Duke Power Company experience, assure that in the unlikely event of a TMI-type l accident hydrogen would not be generated in excess of concen-l tration li=its set forth in~10 CFR 50.44.

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~S-I hereby certify that the above statements are true and correct to the best of my knowledge and belief.

i K.S/Canady Subscribed and sworn to before me on this ~ 9th day of July, 1979.

~

h a B LD Notary Public

~

• This is a telefax copy. Copies of the original are belng sent today from Charlotte, North Carolina to the Board and all parties. .

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