ML20246N471

Provides Comments on Util Response to Generic Ltr 88-17 W/Respect to Expeditious Actions for Loss of DHR for Plant. Response Lacks Some Details Represented in Encl 2 of Generic Ltr.Observations Listed

ML20246N471
Person / Time
Site:	Maine Yankee
Issue date:	05/15/1989
From:	Sears P Office of Nuclear Reactor Regulation
To:	Frizzle C Maine Yankee
References
GL-88-17, TAC-69751, NUDOCS 8905190447
Download: ML20246N471 (4)

Text

_ _ _ _ _ _ _ _ _ __ -_ . ._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

pouruq .'

y*c- A UNITED STATES NUCLEAR REGULATORY COMMISSION f5 g, j WASHINGTON, D. C. 20555 s

%, May 15,1989 Docket No. 50-309, Mr. Charles D. Frizzle, President Maine Yankee Atomic Power Company 83 Edison Drive Augusta, Maine 04330

SUBJECT:

COMMENTS ON THE MAINE YANKEE ATOMIC POWER COMPANY RESPONSE TO GENERIC LETTER 88-17 WITH RESPECT TO EXPEDITIOUS ACTIONS FOR LOSS OF DECAY HEAT REMOVAL FOR MAINE YANKEE PLANT (TAC NO.69751)

Generic Letter (GL) 88-17 was issued on October 17, 1988 to address the potential for loss of decay heat removal (DHR) during nonpower operation. In theGL,werequested(1)adescriptionofyoureffortstoimplementtheeight reconnended expeditious actions of the GL and (2) a description of the enhancements, specific plans and a schedule for implementation of the six reconnended program enhancements.

The NRC staff has reviewed your response to Generic Letter 88-17 on expeditious actions in the letter of January 12, 1989. We find that it appears to meet the intent of the GL but lacks some of the details represented in Enclosure 2 of GL 88-17. Your responses were for the most part complete but brief for some items and therefore did not allow us to fully understand your actions taken in response to GL 88-17. You may wish to consider several observations in order to assure yourselves that the actions are adequately addressed:

1. .You have provided a background of the training lessons to be provided, related to reduced RC5 inventory operation, where lowered loop operations are anticipated, to operations and operations training personnel of your staff. In the GL this item was intended to include all personnel who can affect reduced inventory operation including maintenance personnel. You have stated that crews are briefed and a discussion of applicable material is gone over prior to entering a reduced inventory condition. If maintenance personnel are included at these meetings, the supervisor should inform them of their possible harmful interaction with mid-loop operation. Precautions for avoidance of harmful interaction should be explained, including a back-ground of past problems experienced at other plants and at Maine Yankee if any.

8905190447 890515 PDR P ADOCK 0500030% s PDCI l 1

)

.c Mr. Charles D. Frizzle May 15,1989

2. You state that additional analyses are being performed to better define the time to core uncovery in the event of a worst case loss of RHR coupled with the inability to initiate alternate cooling or inventory makeup. In the meantime in lieu of plant specific calculations, Generic Letter 88-17 states that " containment penetrations including the equipment hatch, may remain open provided closure is reasonably assured within 2.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> of initial loss of DHR." This time will be less if there are vent areas totaling greater than I square inch in the cold leg (see Enclosure 2  ;

Section 2.2.2 of GL 88-17).

3. In some plants, the quick closure of the equipment hatch is achieved by the installation of a reduced number of bolts. If you plan to use less than the full complement of bolts for sealing the equipment hatch then you should first verify that you can make a proper seal of the periphery mating surfaces to meet the closure criteria.

4. In your addressing of containment closure no information is provided regarding how you will keep track of and control the many potential openings which may have to be closed simultaneously. Your procedures and administrative controls should address this topic.

5. For the monitoring of core temperature conditions, you state that with  ;

the reactor vessel head in place, at least two independent core exit thermocouple (CETs) will be operational. You indicate that a process  ;

computer or alternate personal computer will communicate with both the inadequate core cooling (ICC) cabinets or the operator will be stationed at the ICC cabinet to monitor the CET temperature. No mention was made if the ICC will have alarm functions for the CETs.

6. For level measurement, you state that two independent, continuous RCS level indications, meeting the requirements of the GL are provided with procedures governing operation in reduced inventory. No further information is provided regarding the type of level measuring device, its accuracy, and location of the taps. Also, it is not stated if the readings are monitored in the control room and if there is alarm capability. When two instruments are in place, care should be taken to resolve any discrepancy between the two measurement systems. Also, the pressure of reference legs should approximate the pressure in the void in the hot leg or be compensated to obtain a correct value.

7. For the expeditious action regarding provision of at least two available or operable means of adding inventory to the RCS that are in addition to pumps that are a part of the normal DHR systems, you have providea information as follows. Charging /HPSI pumps are used for injection via the normal charging header or via the safety injection system. Another means for adding inventory is gravity feed from the RWST. For the charging pump, you indicate that it is to be lined up to discharge to the normal cold leg injection point. As alluded to in Enclosure 2, Section 2.2.2 of GL 88-17, if openings totaling greater than 1 square inch exist in the cold legs, reactor coolant pumps and cross over piping of the RCS, the

l t Mr. C. D. Frizzle May 15,1989 core can uncover quickly when pressurized under loss of RHR conditions.

If this situation should arise, it is generally more effective to inject makeup water into the hot leg rather than the cold leg. For the other pumps and gravity feed, you indicate that hot leg or cold leg injection is possible. When using gravity drain from the RWST a pro I venting must be in place and verified by calculations'(per means see next for item).

I

8. You indicate that gravity feed from the refueling water storage tank (RWST) is a possible source for makeup to the RCS. You have not stated any specific opening to relieve pressure. The removal of a pressurizer manway or steam generator manway for example, is a means to provide RCS venting. Calculations need to be performed to verify the effectiveness of RCS openings, however, because even for relatively large hot side openings in the RCS, pressurization to several psi can still result. For example, with removal of a pressurizer manway large steam flows in combination with flow restrictions in the surge line and lower pressurizer hardware may still lead to pressurization.

l There is no need to respond to the above observations.

As you are aware, the expeditious actions you have briefly described are an interim measure to achieve an imnediate reduction in risk associated with reduced inventory operation, and these will be supplemented and in some cases replaced by programmed enhancements. Wu intend to audit both your response to the expeditious actions and your programmed enhancement program. The areas where we do not fully understand your responses as indicated above may be covered in the audit of expeditious actions.

This closes out the staff review of your responses to the expeditious actions listed in the GL. The area of programmed enhancements will be addressed in a separate letter.

Sincerely,

. Original Signed by.:

Patrick M. Sears, Project Manager Project Directorate I-3 Division of Reactor Projects I/II cc: See next page DISTRIBUTION: DohEet File, PDI.3 r/f, MRushbrook, SVarga, BBoger, PSears, RWessman, BGrimes, EJordan, ACRS(10), JWiggins,Rgn.I NRC& Local PDRs

[ MAN. YANK. TAC 69751 G.L.88-17]

'M S o :PDI-3  :

OFC :PDI :DIR/PDI-3  :  :  :

NAltE :MRu :PSears:mw :RWe

. .h. . . _ _k  :  :  :

DATE:5/0789 :5/P/89 :5/g/89  :  :  :  : ,

l

\

OFFICIAL RECORD COPY

I .

.,.~

9 .

Mr. C. D. Frizzle _

')

Maine Yankee Atomic Power Company Maine Yankee Atomic Power Station 8 cc:

Mr. C. D. Frizzle, President Maine Yankee Atomic Power Company Mr. P. L. Anderson, Project Manager-83 Edison Drive Yankee Atomic Electric Company {

Augusta, Maine 04336 580 Main Street 4 Bolton, Massachusetts 01740-1398

(

1 Mr. Charles B. Brinkman Mr. G. D. Whittier, Manager "

Manager - Washington Nuclear Nuclear Engineering and. Licensing Operations Maine Yankee Atomic Power Company

_ Combustion Engineering, Inc. 83 Edison Drive 12300 Twinbrook Parkway, Suite 330 Augusta, Maine 04336 Rockville, Md. 20852 John A. Ritsher, Esquire Ropes & Gray 225 Franklin Street Boston, Massachusetts 02110 State Planning Officer Executive Department 189 State Street Augusta, Maine 04330 Dr. E. T. Boulette, Vice President Operations and Plant Manager Maine Yankee Atomic Power Company P. O. Box 408 Wiscasset, Maine 04578 Mr. J. H. Garrity, Vice President Licensing ar.d Engineering Maine Yankee Atomic Power Company 83 Edison Drive Augusta, Maine 04336 Regional Administrator, Region I U.S. Nuclear Regulatory Comission 475 Allendale Road King of Prussia, Pennsylvania 19406 First Selectman of Wiscasset Municipal Building U.S. Route 1 Wiscasset, Maine 04578 Mr. Cornelius F. Holden l Resident Inspector c/o U.S. Nuclear Regulatory Comission P. O. Box E  :

Wiscasset, Maine 04578 L --- _ -- _ _ _ - - - - _ _ _ - - - - - - . - - . - - _ _ - - - _ - - - - . - - - - - - _ _ - - - - - - - - - - - - - _ - - _ - _ _ - _ - - - - --_--