ML20195D412

Safety Evaluation Summary of Inservice Testing Program for Pumps & Valves.Program Acceptable Subj to Listed Conditions in Encl SER

ML20195D412
Person / Time
Site:	LaSalle
Issue date:	05/27/1986
From:	NRC
To:
Shared Package
ML20195D410	List: ML20195D407 ML20195D412 ML20195D417
References
NUDOCS 8606040196
Download: ML20195D412 (5)

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Enclosure 1 Safety Evaluation Summary of Inservice Testing Program for Pumps and Valves for La Salle County Station Unit 1, Docket No. 50-373 In the Safety Evaluation Report (SER) which was issued in March 1981, the NRC staff stated that a detailed review of the La Salle Unit 1 inservice testing (IST) program for pumps and valves had not been completed. The staff therefore performed a preliminary review of the IST program and granted interim relief from certain pump and valve testing requirements of Section XI of the ASME Boiler and Pressure Vessel Code required by 10 CFR 50.55a(g)(2) and 10 CFR 50.55a(g)(4)(i) for a portion of the 120 month period until the staff completed a detailed review of the program. This review of the La Salle Unit 1 IST program for pumps and valves is now complete; and this summary contains an evaluation of the program, based on revisions to the program and other submit-tals up to October 11, 1985. The review of the la Salle Unit 1 IST program is in accordance with Standard Review Plan Section 3.9.6 (NUREG-0800, July 1981).

The licensee will test the pumps and valves within the scope of the La Salle Unit 1 IST program in accordance with Section XI of the ASME Boiler and Pressure Vessel Code, 1980 Edition through the Winter 1980 Addenda, except for certain items where the licensee has requested relief from the testing require-ments of the code. The NRC staff has reviewed these relief requests with the following findings:

1. The licensee in relief request 2.1.2 has requested specific relief from the testing requirement of measuring displacement vibration amplitude for all pumps in the IST program, and as an alternate has proposed measuring vibration velocity for these pumps. The licensee's basis for requesting relief is that velocity is a better indication of vibration severity because it accounts for both the displacement of the vibration and the rate of frequency of displacement. Both of these parameters must be considered when determining the susceptibility to malfunction resulting from fatigue. The NRC staff agrees with the licensee's basis for request-ing relief in that vibration velocity measurements are superior to dis-placement vibration amplitude measurements for monitoring pump degradation; however, the licensee's proposed acceptance criteria for the vibration velocity measurements are not adequate to ensure proper corrective actions are taken if pump degradation occurs.

Accordingly, the licensee's requested relief from the testing requirements of measuring displacement vibration amplitude for all pumps in the IST program is granted; and the licensee's alternate proposal of using vibration velocity measurements for all pumps in the IST program shall be used. However, since the acceptance criteria proposed by the licensee are not acceptable to the NRC staff, the acceptance criteria in Table 2.1.2-1 of Enclosure 2 shall be used in place of those proposed by the licensee as 8606040196 DR 860527 ADOCK 05000373 1 PDR

a condition for this relief. The IST program shall be revised accordingly.

It is concluded that granting this relief will not endanger life or property or the common defense and security and is in the public interest.

2. The licensee in relief request 2.3.1 has requested specific relief from measuring the inlet pressure, differential pressure, and flow rate for the diesel fuel oil transfer pumps in accordance with the requirements of Section XI of the code. The licensee's basis for requesting relief is that the purpose of these pumps is to move fuel oil into the day tank approximately ten times faster than diesel engine consumption rate. The exact flow characteristic of these pumps is not crucial. Also, there is no definable output pressure requirement. For these reasons, the best method of determining degradation trends in pump performance is to measure the flow rate by measuring the time it takes to increase to a certain level in the day tank. It is the NRC staff position that without the measurement of inlet pressure, differential pressure, and flow rate in conformance with Subsection IWV of Section XI of the ASME Code the licensee may not adequately monitor the hydraulic characteristics of these pumps and therefore detect possible pump degradation.

Therefore, the requested relief from the requirements of Subsection IWP of Section XI of the ASME Code is denied, and the licensee is required to modify the diesel fuel oil transfer system prior to the end of the next refueling outage to permit measuring inlet pressure, differential pressure, and flow rate of the diesel fuel oil transfer pumps in accordance with the requirements of the Code. For the balance of the period of the current fuel cycle, interim relief is granted to test the pumps as proposed by the licensee. The modifications necessary to permit the Code-required testing prior to the next refueling outage are impractical and would impose unnecessary hardship on the licensee without compensating increase in the level of safety. Taking into account the inservice tests that will be performed as well as the relatively short operational time until the next refueling outage, it is concluded that this interim relief will not endanger life or property or the common defense and security and is in the public interest for the limited period of time for which this interim relief is granted.

3. The licensee in relief request 3.2.1 has requested specific relief from the power operated stroke timing requirements of all power operated rapid-acting valves whose function is safety-related in accordance with the requirements of Section XI of the Code. The licensee's basis for request-ing relief is that it is impractical to apply the requirements of IWV-3417 (a) to valves with short stroke times (less than five seconds) and has proposed to verify that the stroke time does not exceed five seconds. The NRC staff does not agree with the licensee's basis for requesting relief from the strcke time measurement requirements of the code because we do not believe the Code requirements of IWV-3417 to be impractical for valves with stroke times greater than 2 seconds. The NRC staff has determined that rapid-acting valves are defined as those valves with stroke times of two seconds or less and that valves with stroke times greater than two seconds should be tested in accordance with the requirements of Section XI.

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Therefore, the requested relief from the requirements of Subsection IWV of Section XI of the ASME Code is denied, and the licensee is required to apply the rapid-acting valve definition only to power operated valves with stroke times of two seconds or less. Valves that do not fit this category should be stroke time tested in accordance with the requirements of Section XI.

4. Excluded from the proposed IST program are certain normally closed valves that are classified by the licensee as test valves; properly classified test valves are exempt from the requirements of Section XI of the code.

During pump tests, these full-flow valves receive an isolation signal to shut when the system initiation signal is generated. At this time, the test configuration is automatically secured and the system aligns to the reactor vessel injection flowpath. The full-flow test valves perform a safety function since they must close in order to prevent a diversion of flow from the reactor vessel injection flowpath.

It is the NRC staff position that full-flow test valves in safety-related systems shall be included in the licensee's IST program and tested in accordance with the requirements of Subsection IWV of Section XI of the ASME Code. These full-flow test valves are: High Pressure Core Spray System, IE22-F010, IE22-F011, and IE22-F023; Low Pressure Core Spray System, IE21-F012; Residual Heat Removal System, IE12-F021; Reactor Core Isolation Cooling System, IE51-F022, and IE51-F059.

The IST program shall be revised accordingly.

5. The licensee has omitted from the IST program CRD-115, control rod drive charging water header check valve, and CRD-138 cooling water header check valve, for each of the 185 hydraulic control units (HCU) in the control rod drive (CRD) system. The licensee's basis for omitting the check valves from the IST program is that testing is not necessary because of a modification to the CRD system. This modification is the addition of a charging water low pressure scram which automatically scrams the system whenever the charging water pressure decreases below the scram setpoint.

The NRC staff does not agree with the licensee's basis for omitting these check valves from the IST program since the installation of a low pressure scram does not assure proper operability of individual check valves or identify valve degradation that would interfere with valve operation.

Accordingly, check valves CRD-115 and CRD-138 shall be included in the IST program as Category C valves. However, relief from the testing require-ments of Subsection IWV of Section XI of the ASME Code is granted because testing of the check valves during plant operation is impractical. The check valves shall be tested as follows:

1. In order to verify closure of check valves CRD-115 the test will be performed at refueling when the charging water header can be depres-surized without a plant scram and when area radiation is sufficiently reduced to allow extended entry for testing. Testing will be per-formed by depressurizing the charging water header and monitoring individual accumulation pressu.'e and alarm to verify that check valves CRD-115 have closed on reverse flow.

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2. In order to verify closure of check valves CRD-138, the test will be

performed during integrated leakage testing per 10 CFR 50, Appendix J by venting of the cooling water header to verify that check valves CRD-138 have closed on reverse flow.

The NRC staff concludes that the alternate testing identified above will give reasonable assurance of the operability of check valves CRD-115 and CRD-138 intended by the Code and that the relief thus granted will not endanger life or property or the common defense and security of the public.

6. The licensee in relief request 3.7.3 has requested specific relief from verifying "as-found" set points of safety relief valves in accordance with the requirements of Section XI of the code and proposed to exchange these i

valves with valves whose set points have been verified. These valves are:

1B 21- F013 A , 1821- F0138 , 1821- F 013 C , 1821- F0130 , 1821- F013 E , 1821- F013 F ,

IB21-F013G, 1821-F013H, 1821-F013J, 1821-F013K, 1821-F013L, 1821-F013M, 1821-F013N, 1821-F013P. The licensee's basis for requesting relief is that it is impractical to meet the requirements of IW-3510 in that as-found set points for these valves cannot be determined because there is no on-site facility for testing safety valve set points. The licensee there-fore plans to ship the valves off-site where they will be rebuilt and the j set points tested. The number of valves removed and replaced during refueling outages will be determined by the schedule in IW-3510. The NRC staff agrees that off-site testing of safety relief valves is an ac-ceptable alternate method of verifying valve set points due to the lack of j on-site testing equipment and is therefore acceptable. However, the licensee has not addressed additional tests required by IW-3513.

IW-3513 requires that when any valve in a system fails to function properly during a regular test, additional valves shall be tested. If any additional valves fail to function properly on test, then all valves in the system in this category shall be tested.

Therefore, the requested relief from verifying "as-found" set points of the safety relief valves is denied, and the licensee is required to have the set points tested prior to startup from the outage during which they are removed and prior to being rebuilt in order to comply with IW-3513.

In addition, if the tested valves that are removed fail their set pressure test acceptance criteria, additional valves shall be removed and tested prior to restart in accordance with IW-3513.

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The NRC staff concludes that this testing will give reasonable assurance

• of valve operability intended by the Code and that the relief thus granted to allow the valve setpoints to be determined offsite will not endanger life or property or the common defense and security of the public.

7. The NRC staff in its review of the proposed IST program identified certain valves that perform a containment isolation function. These values are either not included in the IST program or if they are included, they are not categorized A or A/C as appropriate and are not leak tested in accor-dance with 10 CFR 50, Appendix J, " Containment Isolation Valve Criteria."

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It is the NRC staff position that the following valves are to be included in the licensee's IST program and categorized A or A/C as appropriate:

High Pressure Core Spray System 1E22-F023; Drywell Instrument Nitrogen System IIN100, lIN101; Low Pressure Core Spray 1E21-F012; Suppression Pool Water Level Vacuum Breaker System 1CM004, 1CM012; Residual Heat Removal System 1E12-F099A, 1E12-F0998, 1E12-F021; Containment Monitoring System 1CM022A, 1CM024A, 1CM025A, 1CM0218, 1CM0238, 1CM0268.

The IST program shall be revised accordingly.

Apart from the items identified above, the licensee has requested relief from certain other pump and valve testing requirements of 10 CFR 50.55a(g)(2) and (g)(4)(i) as discussed in detail in Enclosure 2. For those specific relief requests as addressed in Enclosure 2, the NRC Staff finds that it is imprac-tical within the limitations of the LaSalle Unit 1 plant design, geometry, and accessibility for the licensee to meet the noted requirements of the ASME Code and that relief is authorized by law, will not endanger life or property or the common defense and security, and is otherwise in the public interest consider-ing the burden on the licensee if the relief were not granted. Accordingly, the specific relief as discussed and conditioned in Enclosure 2 and in this SER Summary is granted for the initial 120 month period of the IST program. With these stipulations, the modifications to the IST program noted above, and this grant of relief, the NRC Staff finds the LaSalle Unit 1 IST program for pumps and valves acceptable and in conformance with the Commission's regulations.

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