ML20247A974
| ML20247A974 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 07/18/1989 |
| From: | Fairtile M Office of Nuclear Reactor Regulation |
| To: | Papanic G YANKEE ATOMIC ELECTRIC CO. |
| References | |
| GL-88-17, TAC-69794, NUDOCS 8907240007 | |
| Download: ML20247A974 (5) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION o
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July 18,1989 Docket No. 50-29 Mr. George Papanic, Jr.
l Senior Project Engineer-Licensing Yankee Atomic Electric Company 580 Main Street Bolton, Massachusetts 01740-1398
Dear Mr. Papanic:
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SUBJECT:
COMMENTS ON THE YANKEE ATOMIC ELECTRIC COMPANY RESPONSE TO GENERIC LETTER 88-17 WITH RESPECT TO EXPEDITIOUS ACTIONS FOR LOSS OF DECAY HEAT REMOVAL FOR YANKEE R0WE PLANT (TAC NO. 69794)
Generic Letter (GL) 88-17 was issued on October 17, 1988 to address the potential for loss of decay heat removal (DHR) during ninpower operation.
In the GL, we requested (1) a description of your efforts to implement the eight recommended expeditious actions of the GL.and (2) a description of the enhancements, specific plans and a schedule for implementation of the six recommended program enhancements.
The NRC staff has reviewed your response to Gl 98-17 on expeditious actions in the letter of January 3,1989. We find that e 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 complety, 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 RCS inventory operation, where lowered loop operations are anticipated, to operators of your staff.
In the GL this item was intended to include all personnel who can affect reduced inventory operation including maintenance personnel.
2.
You state that additional analyses were 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.
You indicate that you have plant-specific calculations that supersede the closure time in the GL 88-17. One statement in GL 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."
However, the closure 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). Your analyses should have addressed the possibility of this size of opening in the cold leg.
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e Mr. George Papanic, Jr.
-2 July 18,1989 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.
You state that " based upon the times calculated to core uncovery, the
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necessary provisions are implemented to ensure any open penetrations can be closed before core uncovery occurs."
In your addressing of containment closure no speciff-information is provided regarding how you will keep track of and control the many potential openings which may have to be closed simultaneously. We assume your procedures and administrative controls will address this topic.
5.
You state that two independent RCS level indicators are to be installed prior to drain-down. Both level indicators will use a clear plastic hose and be connected to one loop with separate taps. The reference tap location is not provided.
You state that liquid level will be remotely observed by an operator in containment by a video monitor and will be recorded every 15 minutes. Communication will be established between the operator in containment and in the control room. Although this type of L
arrangement is adequate for the expeditious actions, a more permanent arrangement is needed for the prcgrammed enhancements.
You indicate that another remote level indicator is available in the control room but.have not described what type it is, where the taps are located and its range and accuracy. However, you state that it is less accurate than the level hoses and is therefore only used as a backup. 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.
6.
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 provided two methods. One method uses high pressure charging pumps and the other method uses a purification pump. You have not described the injection path. 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 crossover piping of the RCS, the 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.
You indicate that openings in the cold leg piping could require flow rates.for recovery that require the use of the safety injection system, but that in certain modes SIS operation is precluded by the present Technical Specifications.
Therefore, you are limiting maintenance to hot leg valves until the necessary Technical Specification modifications can be made. Modifying Technical Specifications for improved operatis a is one of the steps we recommend as stated in the programmed enhancements.
Mr. George Papanic, Jr. July 18,1.989 -
1 f
7.
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
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and lower pressurizer hardware may still lead to pressurization.
There is no need to respond to the above observations.
As you are aware, the expeditiou, actions you have briefly described are an interim measure to achieve an immediate reduction in risk associated with reduced inventory operation, and these will be supplemented and in some cases replaced by programmed enhancements. We 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 j
separate letter.
Sincerely, q
Original signed by:
Morton B. Fairtile, Project Manager Project Directorate I-3 Division of Reactor Projects I/II cc: See next page i
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YANKEE R0WE GL 8817 4
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0FFICIAL RECORD COPY
i Mr. George Papanic, Jr.
Yankee Atomic Electric Company Yankee Nuclear Power Station
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Dr. Andrew C. Kadak, President and Chief Operating Officer Mr. George Papanic, Jr.
Yankee Atomic Electric Company Senior Project Engineer-Licensing 580 Main Street Yankee Atomic Electric Company Bolton, Massachusetts 01740-1398 580 Main Street' Bolton, Massachusetts 01740-1398 i
Thomas Dignan, Esquire Ropes and Gray Mr. George Sterzinger 225 Franklin Street Commissioner Boston, Massachusetts 02110 Vermont Department of Public Service l
Mr. N. N. St. Laurent 120 State Street, 3rd Floor Plant Superintendent Montpelier, Vermont 05602 Yankee Atomic Electric Company Star Route Rowe, Massachusetts 01367 Resident Inspector Yankee Nuclear Power Station c/o U.S. NRC 1
Post Office Box 28 Monroe Bridge, Massachusetts: 01350 Regional Administrator, Region I U.S. Nuclear Regulatory temmission 475 Allendale Road King of Prussia, Pennsylvania 19406 Robert M. Hallisey, Director Radiation Control Program Massachusetts Department of Public Health i
150 Tremont Street, 7th Floor
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