ML14188B618

Comments on Util 890103 Response to Generic Ltr 88-17 Re Expeditious Actions for Loss of Dhr.Response Appears to Meet Intent of Ltr.Observations to Assure Actions Adequately Addressed Listed

ML14188B618
Person / Time
Site:	Robinson
Issue date:	06/08/1989
From:	Lo R Office of Nuclear Reactor Regulation
To:	Eury L Carolina Power & Light Co
References
GL-88-017, TAC-69770 NUDOCS 8906140215
Download: ML14188B618 (4)

Text

%41REGUI UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 June 8. 1989 Docket No. 50-261 Mr. Lynn W. Eury Executive Vice President Power Supply Carolina Power & Light Company P. 0. Box 1551 Raleigh, North Carolina 27602

SUBJECT:

COMMENTS ON THE CAROLINA POWER COMPANY RESPONSE TO GENERIC LETTER 88-17 WITH RESPECT TO EXPEDITIOUS ACTIONS FOR LOSS OF DECAY HEAT REMOVAL FOR H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 (TAC 69770)

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 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 enhance ments.

The NRC staff has reviewed your response to GL 88-17 on expeditious actions in the letter of January 3, 1989. We find that your response appears to meet the intent of the GL with respect to expeditious actions. However, your response is so brief and sufficiently vague that we cannot 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 brief discussion of training and a list of source material related to loss of DHR for licensed personnel of your staff. Your brief response does not specifically state that maintenance personnel are are also included in any of the training. The item was intended to include all personnel who can affect reduced inventory operation.

2. You have not presented any times for containment closure. You may have plant specific times for containment closure based on plant specific calculations. If these calculations have not been completed, 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 1 square inch in the cold leg (see, Section 2.2.2 of GL 88-17).

8906140215 890608 PDR ADOCK 05000261 P

PDC

Mr. Lynn June 8, 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. Your addressing of containment closure provided no information regarding how you will keep track of and control the many potential openings (piping, electrical, hatches) which may have to be closed simultaneously.

We assume your procedures and administrative controls will address this topic.

5. You state that you will have three level indicators; two standpipes and one "control room."

You have not provided a description of these three levels of systems.

You mention that one system is a standpipe which has a common tap to the level transmitter providing control room indication.

We assume it is a tygon tube standpipe. You have not provided information on its range or accuracy. You have stated that the standpipe reading will be monitored by an operator stationed inside of containment and that the reading will be forwarded every 15 minutes during reduced inventory conditions to the control room for logging. You have stated that a second reactor coolant system (RCS) level standpipe will also be installed on a separate RCS loop. When two or more level instruments are in place, care should be taken to resolve any discrepancy between the measurement systems.

Also, the pressure of the reference leg should approximate the pressure of the void in the hot leg or be compensated to obtain the correct level value.

6. Walking the tygon tube following installation to verify lack of kinks or loop seals is necessary. Experience shows that periodic walkdowns are needed after installation. We recommend daily walkdowns when the tygon tube is in use, with an additional walkdown immediately prior to its being placed in use.

7. You have provided information on two means of adding inventory to the RCS that are in addition to pumps that are part of the normal DHR systems.

One of these means is a safety injection pump. The second means is a charging pump. However, 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.

8. You have not stated the use of any specific vent openings on the hot side of the RCS to relieve RCS pressurization. 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.

Mr. Lynn June 8, 1989 There is no need for you to respond to the NRC staff on the above observations.

As you are aware, the expeditious 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 on your programmed enhancements. 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:

Ronnie H. Lo, Sr. Project Manager Project Directorate II-1 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation cc:

See next page DISTRIBUTION Docket File NRC & Local PDRs PDII-2 Reading S. Varga G. Lainas E. Adensam P. Anderson R. Lo OGC (for your info.)

E. Jordan B. Grimes W. Hodges H. Balukjian ACRS (10)

Robinson File LA.

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Mr. L. W. Eury H. B. Robinson Steam Electric Carolina Power & Light Company Plant, Unit No. 2 cc:

Mr. R. E. Jones, General Counsel Mr. Dayne H. Brown, Chief Carolina Power & Light Company Radiation Protection Branch P. 0. Box 1551 Division of Facility Services Raleigh, North Carolina 27602 Department of Human Resources 701 Barbour Drive Raleigh, North Carolina 27603-2008 Mr. McCuen Morrell, Chairman Darlington County Board of Supervisors Mr. Robert P. Gruber County Courthouse Executive Director Darlington, South Carolina 29535 Public Staff - NCUC P. 0. Box 29520 Mr. H. A. Cole Raleigh, North Carolina 27626-0520 Special Deputy Attorney General State of North Carolina Mr. C. R. Dietz P. 0. Box 629 Manager, Robinson Nuclear Project Raleigh, North Carolina 27602 Department H. B. Robinson Steam Electric Plant Mr. D. E. Hollar P. 0. Box 790 Associate General Counsel Hartsville, South Carolina 29550 Carolina Power & Light Company P. 0. Box 1551 Attorney General Raleigh, North Carolina 27602 P. 0. Box 11549 Columbia, South Carolina 29211 U.S. Nuclear Regulatory Commission Resident Inspector's Office Mr. Heyward G. Shealy, Chief H. B. Robinson Steam Electric Plant Bureau of Radiological Health Route 5, Box 413 South Carolina Department of Health Hartsville, South Carolina 29550 and Environmental Control 2600 Bull Street Regional Administrator, Region II Columbia, South Carolina 29201 U.S. Nuclear Regulatory Commission 101 Marietta Street Suite 2900 Atlanta, Georgia 30323 Mr. R. Morgan General Manager H. B. Robinson Steam Electric Plant P. 0. Box 790 Hartsville, South Carolina.29550