ML20203N316

Forwards Addl Info on Proposed Preventive Maint Program for CRD & Orifice Assemblies,In Response to 860707 Request

ML20203N316
Person / Time
Site:	Fort Saint Vrain
Issue date:	09/19/1986
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	Berkow H Office of Nuclear Reactor Regulation
References
P-86547, TAC-61066, NUDOCS 8609230311
Download: ML20203N316 (9)

Text

---

1 1

PublicService . . . .

Company of Colorado 16805 WCR 19 1/2, Platteville, Colorado 80651 September 19, 1986 Fort St. Vrain Unit No. 1 P-86547 Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Mr. H. N. Berkow, Director Standardization and Special Projects Directorate Docket No. 50-267

SUBJECT:

CONTROL R0D DRIVE AND ORIFICING ASSEMBLY (CRD0A) PREVENTIVE MAINTENANCE PROGRAM

REFERENCE:

See Attachment 1

Dear Mr. Berkow:

In Reference 1, the NRC requested PSC to provide additional information on the proposed Preventive Maintenance Program for the Control Rod Drive and Orifice Assemblies. A previous submittal (Reference 2) summarized the proposed program. The additional information requested is included as Attachment 2 for your review.

We hope you will find this submittal responsive to your concerns. If you have any questions or comments, please call Mr. M.H. Holmes at (303) 480-6960.

Sincerely,

/5 A

.W. ahm

' Manager, Nuclear Production Fort St. Vrain Nuclear Generating Station JWG:JKE/jlf Attachments d

8609230311 e60919 I it PDR ADOCK 05000267 P PDR n

4 P-86547 September 19, 1986

' Attachment 1 l Page 1 ATTACHMENT 1 REFERENCES

1. G-86371, NRC Letter, Heitner to Walker, dated 07/07/86.

2. P-86078, PSC Letter, Gahm to Berkow, dated 02/03/86.

3. P-86494, PSC Letter, Warembourg to Berkow, dated 07/31/86.

4. P-85037, PSC Letter, Warembourg to Johnson, dated 01/31/85.

5. P-86525, PSC Letter, Gahm to Berkow, dated 08/19/86.

4

P-86547 September 19, 1986 Attachment 2 Page 1 ATTACHMENT 2 ADDITIONAL INFORMATION - PREVENTIVE MAINTENANCE PROGRAM FOR CONTROL R0D DRIVE AND ORIFICE ASSEMBLIES (1) PLEASE PROVIDE THE ACCEPTANCE CRITERIA FOR THE VISUAL INSPECTIONS OF THE FOLLOWING COMPONENTS LISTED IN YOUR PROPOSED PREVENTATIVE MAINTENANCE PROGRAM:

Visual examinations are used to obtain subjective indications of a component's overall condition and to identify adverse conditions which could affect a component's performance. The actual determination of acceptable performance is based upon quantifiable parameters such as Back-EMF, torque, wattage, megger readings, etc. Visual examinations are intended to be indicative of potential problems.

If the acceptance criteria is not satisfied, then a Non-Conformance Report (NCR) is written. An engineering resolution is required to close the NCR.

• Shim Motor / Brake Assembly, Pinion Gear Acceptance Criteria: No ' wear, corrosion, or defect which could affect the ability to engage with first stage gear or which could affect the ability of the shim motor to scram or drive the gear train.

Note: The Back-EMF and shim motor / brake assembly '

torque with shim motor / brake assembly installed are the definitive criteria for CR00A operation.

• Shim Motor / Brake Assembly, Brake Pads Acceptance Criteria: No wear, corrosion or defect l which could affect the ability of the brake pads to hold control rods in position or which could prevent

shim motor from rotating freely when brake is released.

l l

P-86547 September 19, 1986 Attachment 2 Page 2.

I Note: The Back-EMF and shim motor / brake assembly torque with shim motor / brake assembly installed are the definitive criteria for CRD0A operation.

• Drive Train Acceptance Criteria: No wear, corrosion, or defects on visible gears and pinions which could affect their ability to engage or which could affect the ability of.

the gear train to allow the control rods to insert into reactor.

Note: The Back-EMF and shim motor / brake assembly torque with shim motor / brake assembly installed are the definitive criteria for CRD0A operation.

• Cable Acceptance Criteria: No broken wires, kinking, crushing, bird caging or other condition which could affect the ability to insert the control rods.

Note: The Back-EMF and shim motor / brake assembly torque with shim motor / brake assembly installed are the definitive criteria for CRDOA operation.

• Reserve Shutdown System, Hopper Acceptance Criteria: For surveilled hoppers evidencing RSD material degradation or surveilled by testing, empty hopper is free of foreign material and obstructions which could prevent the free flow of reserve shutdown material.

. Note: Two reserve shutdown syr.tems will be functionally tested at each refueling outage. This test will consist of pressurizing the reserve shutdown hopper to the point of rupturing the disc and releasing the poison material (Interim Technical Specifications, Surveillance Requirements 4.1.9(D)(4)).

_ _ - . _ __._ - . _- - - , _ _ .~ ___ _ . _ _

P-86547 '

September 19, 1986 Attachment 2 '

Page 3

.  :. Reserve Shutdown System, Material Acceptance Criteria: No foreign material or deposits

, on the observable RSD material in situ which could cause agglomeration or bridging or which could prevent-the free flow of reserve shutdown material.

Note: Two reserve shutdown systems will be functionally tested at each refueling outage. This test will consist of pressurizing the reserve shutdown hopper to the point of rupturing the disc and releasing the poison material (Interim Technical Specifications, Surveillance Requirements 4.1.9(D)(4)).

• Orifice Drive Motor Assembly Acceptance Criteria: No wear, corrosion, or defects which could affect the ability of the assembly to position the orifice valve.

Note: Actual stroking of orifice valve is the

definitive criteria.

Lower Seal Acceptance Criteria: No scratches, nicks, or defects which could affect ability to seal.

Note: No definitive criteria is necessary. This seal's function is to reduce hot gas flow into the -

200 assembly. CRD0A temperatures are monitored by Interim Technical Specification Surveillance Requirement 4.1.1(A)(1).

• Primary Seal - 600 Assembly Acceptance Criteria: No scratches, nicks, or defects which could affect ability to seal.

Note: A leak test is performed (SR-RE-48-X) when a CRDOA is installed in a CRDOA penetration. Passing this test demonstrates the operability of the Primary Seal - 600 Assembly and Primary Seal - 200 Assembly.

P-86547 September 19, 1986-Attachment 2 Page 4

• Primary Seal - 200 Assembly Acceptance Criteria: No scratches, nicks, or defects which could affect ability to seal.

Note: A leak test is performed (SR-RE-48-X) when a CRD0A is installed in a CRD0A penetration. Passing this test demonstrates the operability of the Primary .

Seal - 200 Assembly and Primary Seal - 600 Assembly.

(2)PLEASE DESCRIBE THE NATURE OF THE ANALYSES AND ACCEPTANCE CRITERIA APPLIED TO THE RESULTS OF THESE ANALYSES FOR THE FOLLOWING ITEMS:

• Surface Wipes of the Cable If surface deposits are seen on the cables, an effort will be made to obtain a sample. The degree of effort will be related to the amount of surface deposit in relation to the potential radiation exposure to gather the sample. The purpose of sampling will be to determine the nature of the deposit so that a source can be projected and so the potential effect can be determined.

I The sample will be analyzed in accordance with PSC's Quality Assurance program. The results will be reviewed by engineering personnel.

Acceptance Criteria: No surface deposits which could affect the ability to insert control rods.

• Materials From Reserve Shutdown System Absorber material from the tested hoppers (Interim Technical Specification 4.1.9(D)(4)) shall be visually examined for evidence of Boric Acid crystal formation and chemically analyzed for Boron Carbide and Leachable Boron content.

The sample will be analyzed in accordance with PSC's Quality Assurance program. The results will be reviewed by engineering personnel.

~

g, T o <

k

,i[5 s P-86547 .

September 19, 1986 Attachment 2 Page 5 Acceptance Criteria: No foreign. material or deposits which could cause agglomeration or bridging, or which could- prevent the free flow' of reserve shutdown material.

Note: Two' ceserve- shutdown systems. will be functionally tested at' leach refueling outage. This test will consist of pressurizing the reserve shutdown hopper to the point'of rupturing the disc and releasing the poison material (Ir.terim Technical Specifications 4.1.9(D)(4)).

(3) PLEASE PROVIDE ACCEPTANCE VALUES FOR THE MEASURED TORQUES IN THE FOLLOWING COMPONENTS:

• Shim Motor / Brake Assembly - Installed on CRDOA Acceptance Criteria: With control rods or test weights installed and with control rods or test weights at full in position, the torque to initiate rotation of shim motor / brake assembly shall be less than or equal to 18.0 inch ounces.

• Shim Motor / Brake Assembly - Removed From CRDOA Acceptance Criteria: With no load applied to shim motor / brake assembly the torque to initiate rotation shall be less than or equal to 12.0 inch ounces.

Driv.e Train

- A:ceptance~ Criteria: Not appropriate, see Shim Motor / Brake Arsembly-Installed on CR00A.

!The torque required to rotate the drive train is included with the torque. of the shim motor / brake cassee.bly when it is installed on CRD0A.

(4) PROVIDE ACCEPTANCE VALUES FOR THE MEASURED BACK-EMF IN THE FOLLOMNG COMPONENTS:

Shim ,Mp, tor / Brake Assemb1_y Acceptance Criteria: Not approu*iate, see Drive Train.

t 1

,,,,e v n--n .,-,-n . n.e- .,,w, - - - - - -- , ,-. . =,,-n.- .--

P-86547 September 19, 1986 Attachment 2 Page 6 4

The Back-EMF measures the performance of the shim motor / brake assembly and the drive train together as a system.

• Drive Train Current Acceptance Criteria:  ;

Initial acceleration greater than or equal to i 98.83 rad /sec8 .

Steady state moment less than or equal to 7.0 inch q ounces.

Discussion:

The Back-EMF measures the performance of the CRD0A as a total integrated system rather than as a series of individual components. '

The current acceptance criteria for the Back-EMF was established for the 1985 Refurbishment Program. The acceptance criteria controls limits (1) on the average acceleration of the CRDOA from rest to peak angular velocity during a scram and (2) on the maximum resultant moment on shim motor shaft during steady state portion scram. The current acceptance criteria are based upon initiating a scram from the fully withdrawn position.

A detailed discussion of the methods used to calculate these parameters is included in Section 3.3.4 of Reference 4. The basis for the current ,

acceptance criteria are included in Section 4.1.3 i of Reference 4.

(5) PLEASE PROVIDE ACCEPTANCE VALUES FOR THE MEGGER MOTOR TESTS.

Acceptance criteria: Insulation resistance of shim motor stator and brake coil must be at least one megohm when measured using a 500 volt DC megger.

(6) PLEASE SPECIFY THE CLEANING AND LUBRICATION PROCEDURES TO BE USED IN THE MAINTENANCE PROGRAM. v

r 7 ,

. 1

(,'>i ,

l J

s

.

• P-86547

' > September 19, 1986

s Attachment 2 Page 7 4

• Cleaning Parts will be cleaned at two levels. The first level will be to remove loose contamination by wiping down with " lint free" rags. This level of cleaning should be satisfactory for most parts. ,

I The second level will be to use ultrasonic cleaning with solutions appropriate to the part being cleaned.

Four ultrasoniccredningproceduresweredevelopedfor the 1985 Refurbishment Program that comply with the intent of General Atomic Reference Specification RC 2, Issue A, dated 2/17/69, titled " Cleaning of Metals -

Class A". These ultrasone. cleaning procedures are documented in CN 1933A.

= Lubricating-Solid"F'ilm Reference Specification, RL-1-1 is used to coat items with a solid film lubricant suitable for use in an inert gas and nuclear radiation environment at temperatures ranging from -300 to 750* Fahrenheit.

This reference specification was used for the original solid film,1ubrication of the CRD0A's.

Reference Specification, RL-1-2 is used to define the burnish.ing and assembling requirements for solid film

!, lubricated parts. This reference specification was p' -

used for the original burnishment and assembly, c

1 Lubrication - Other Parts other than those lubricated with solid film lubricar,t will be lubricated using approved lubricants

- < equivalent to those used in original manufacture.

,- , . - , . . . - - r --- . ~ v . , . - c. m.. ,------------.--m- ,