ML14190A655

Forwards Request for Addl Info Re Review of Util Submittals on TMI Item II.B.1, RCS High Point Vents

ML14190A655
Person / Time
Site:	Robinson
Issue date:	03/18/1982
From:	Varga S Office of Nuclear Reactor Regulation
To:	Jackie Jones Carolina Power & Light Co
References
TASK-2.B.1, TASK-TM NUDOCS 8204010051
Download: ML14190A655 (6)

Text

MAR 1 8 1982 Distribution Docket No. 50-261 Docket File Local PDR

~A ORB #1 Rdg MWAR 2 2 1982z.

DHisenhut US RILAIR NOy CoI 5

Mr. J. A. Jones OELD DOCUIT MANGEMP OR Senior Executive Vice President Carolina Power and Light Company GRequa 336 Fayetteville Street CParrish Raleigh, North Carolina 27602 NSIC ACRS (10)

DearDMr. Jones:

JHeltemes

SUBJECT:

REACTOR COOLANT SYSTEM VENTS (ITEM II.B.l)

REQUEST FOR ADDITIONAL INFORMATION We have completed a preliminary review of your submittal(s) regarding TMI Action Plan'Item II.B.l, RCS.High Point Vents. The additional information identified in the enclosure is required to complete our review for your faci iile ty.

We are currently in the process of reviewing.-the technical merit of the proposed operating guidelines for RCS Vent usage. We recommend that the questions in this area be resolved generically through the Owners Groups.

Specific plant procedures will be reviewed against the approved guidelines as needed in the future, but not necessarily prior to design approval.

Please supply the requested information within 60 days of the date of this letter.

The reporting and/or recordkeeping requirements contained In this letter are approved under OMB clearance #3150-0,065 which expires 5/31/83.

Sincerely, original signed byP S. A. Varga Steven A. Vargaj Chief Operating Reactors Branch 1 Division of Licensing En(osure:

As stated cc: See next page

§8204010051 820318 REQUESTADOCK 05000261

<P PDR SURNAME i enti uainst a

NRC FORM 318'(10-80) NRCM 0240 N-OFFICIAL RECORD C OPY

USG, facility.-

Mr. J. A. Jones Carolina Power and Light Company cc: G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.Y.

Washington, D. C. 20036 Hartsville Memorial Library Home and Fifth Avenues Hartsville, South Carolina 29550 U. S. Nuclear Regulatory Commission Resident Inspector's Office H. B. Robinson Steam Electric Plant Route 5, Box 266-1A Hartsville, South Carolina 29550 Alan S. Rosenthal, Chairman Atomic Safety and Licensing Appeal Board Panel U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Richard S. Salzman Atomic Safety and Licensing Appeal Board Panel U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr. W. Reed Johnson Atomic Safety and Licensing Appeal Board Panel U. S. Nuclear Regulatory Commission Washington, D. C. 20555 James P. O'Reilly Regional Administrator - Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303

REQUEST FOR ADDITIONAL INFORMATION FOR ROBINSON 2

1.

'Verify that the reactor coolant gas vent system (RCGVS) vents are smaller than the size corresponding to the definition of a loss-of-coolant accident (10 CF.R Part 50, Appendix A) by providing the pertinent design parameters of the reactor coolant makeup system and a calculation of the maximum rate of loss of reactor coolant from the largest RCGVS break that can be postulated (reference NUREG-0737 Item II.B.1 Clarification A.(4)).

2.

The following items apply to the portions of the RCGVS that form a part of the reactor coolant pressure boundary, up to and including the second normally closed valve (reference NUREG-0737 Item II.B.1 Clarification A.(7)):

a. Verify that the piping, valves, components, and supports are classified Seismic Category I and Safety Class 2 (Safety Class I where the size corresponds to the 10 CFR Part 50 Appendix A definition of a loss-of-coolant accident).

b. Describe the instrumentation that has been provided to detect and measure RCGVS isolation valve seat leakage (reference Appendix A to 10 CFR Part 50, General Design Criterion 30).

c.

Describe the materials of construction and verify that they are compatible with the reactor coolant chemistry and will be fabricated and tested in accordance with SRP Section 5.2.3, "Reactor Coolant Pressure Boundary Materials."

d. Demonstrate that internal missiles and the dynamic effects associated with the postulated rupture of piping will not prevent the essential operation of the RCGVS (i.e., at least one vent path remains fur ctional) (reference Appendix A to 10 CFR Part 50, General Design Criterion 4).

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b.

In which any nearby structures, systems, and components essentic to safe shutdown of the reactor or mitigation of a design basis accident are capable of withstanding the effects of the anticipated mixtures of steam, liquid, and noncondensible gas discharging from the RCGVS (reference NUREG-0737 item II.B.1 Clarification A.(9)).

6.

Verify that operability testing of the RCGVS valves will be performed in accordance with subsection IWV of Section XI of the ASME Code for Category B valves (reference NUREG-0737 Item 11.B.1 Clarification A.(I I)).

7.

Submit operating guidelines for use of the RCGVS including the following:

a.

Guidelines to determine when the operator should and should not manually initiate venting, and information and instrumentation required for this determination (reference NUREG-0737 Item 11.B.1 Clarification A.(2)).

The guidelines to determine whether or not to vent should cover a variety of reactor coolant system conditions (e.g., pressures and temperatures).

The effect of the containment hydrogen concentration on the decision to vent or to continue venting should also be addressed considering the balance between the need for increased core cooling and decreased containment integrity due to elevated hydrogen levels.

b. Methods for determining the.size and location of a noncondensible gas bubble (reference Position (2) and Clarification A.(2)).

c.

Guidelines for operator use of the

vents, including information and instrumentation available to the operetor for initiating or terminating vent usage (reference Position (2)).

d. Required operator actions in the event of inadvertent opening, or failure to close after opening, of the vents including a description of the provisions and instrumentation necessary to detect and correct these fault conditions (reference Position (2) and Clarification A.(2)).

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e.

Methods which in lieu of venting will assure that sufficient liquid or steam will flow through the steam generator U-tube region so that decay heat can be effectively removed from the reactor coolant system (reference Clarification C.(2)).

8.

Verify that all displays (including alarms) and controls, added to the control room as a result of the TMI Action Plan requirement for reactor coolant system vents, have been or will be considered in the human factors analysis required by NUREG-0737 Item 1.D.1, "Control-Room Design Reviews."

9.

Verify that positive valve position indication is provided in the control room for the RCGVS valves (reference NUREG-0737 Item 11.B.1 Clarification A.(5)).

10.

Provide the source of Class IE power supplied to each vent valve in order to verify that a degree of redundancy has been provided by powering different vent paths from different emergency buses (reference NUREG-0737 Item II.B.1, Changes to Previous Requirements and Guidance (4)).

I1.

Provide electrical schematics and piping and instrumentation diagrams for the RCGVS (reference NUREG-0737 Item 11.B.

Documentation Required (3)).

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3.

Verify that the following RCGVS failures have been analyzed and found not to prevent the essential operation of safety-related systems required for safe reactor shutdown or mitigation of the consequences of a design basis accident:

a. Seismic failure of RCGVS components that are not designed to withstand the safe shutdown earthquake.

b. Postulated missiles generated by failure of RCGVS components.

c.

Dynamic effects associated with the postulated rupture of RCGVS piping greater than one-inch nominal size.

d. Fluid sprays from RCGVS component failures.,

Sprays from normally unpressurized portions of the RCGVS that are Seismic Category I and Safety Class 1, 2, or 3 and have instrumentation for detection of leakage from upstream isolation valves need not be considered.

4.

Provide a failure mode and effects analysis (FMEA), as noted in your December 31, 1979 submittal, that shows that no single active component failure, human error, or test and maintenance action could result in inadvertent opening or failure to close after intentional opening of an RCGVS path. Include in the analysis components in the associated power, instrumentation, and control systems as well as the electrical and mechanical components of the RCGVS.

Describe the design features, such as block valves and fail closed valves, or administrative procedures that will be employed to prevent inadvertent or irreversible actuation (reference NUREG-0737 Item II.B.1 Clarification A.(7) and (8)).

5.

Describe, using engineering drawings (including isometrics) and design descriptions as appropriate, where the RCGVS discharges and demonstrate that the RCGVS paths to the containment atmosphere discharge into areas:

a. That provide good mixing with containment air to prevent the accumulation or pocketing of high concentrations of hydrogen, and 13i/RAI-P-23 Page 2 of 4