IR 05000285/1987022

Insp Rept 50-285/87-22 on 870817-21.Major Areas Inspected: Maint & Testing Records,Insp & Testing Procedures,Valve Location & Sys Drawings

ML20237E177
Person / Time
Site:	Fort Calhoun
Issue date:	12/17/1987
From:	Baker E, Paul Prescott Office of Nuclear Reactor Regulation
To:
Shared Package
ML20237E169	List: IR 05000285/1987022 ML20237E167
References
50-285-87-22, NUDOCS 8712280194
Download: ML20237E177 (8)

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UNITED STATES

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NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION Report No.: 50-285/87-22 Docket No.: 50-285 License No.: DPR-40

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Licensee: Omaha Public Power District Facility: Fort Calhoun Station, Fort Calhoun, Nebraska Inspection At: Fort Calhoun Station

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Dates: August 17-21, 1987 Inspectors: UN2 [M Edward T. Baker', Team reader, Program Development and Dats

ReactiveInspectionSection(PDRIS)

$ $4 U 7 Peter J. Prescott, FDR15 C Date Approved By: kLr I Edward T. Baker, Acting Chief, PDRIS, Vendor k/'/P'2 Dats

. Inspection Branch Inspection Summary: Inspection on August 17-21, 198 Areas Inspected: This special announced inspection was conducted at Fort Calhoun Station to determine to what extent the ASME Boiler and Pressure Yessel Code, Section XT, and 10 CFR 50, Appendix J. valve testing programs verified check valve disk and seat integrity. The inspectors also reviewed the licensee's response to INP0's SOER 86-03, concerning check valves. The areas inspected included maintenance and testing records, inspection and testing procedures, valve location with respect to flow disturbances (e.g., elbows and pump discharges),andsystemdrawing Results: The inspectors found that (1) a maintenance procedure for post maintenance testing did not cover the appropriate valves; (2) a maintenance order was written to investigate a noise in check valve AC-104 and cancelled because no parts were available to perform the maintenance; no evidence existed that maintenance was performed after the maintenance order was cancelled; and (3) check valves are not being tested to ensure that all safety functions, pressure isolation as well as passing flow, are being adequately tested. The Ft. Calhoun program does not appear to aggressively address the issue of ensuring that check valves are functional. This was reflected in the Ft. Calhoun response to SOER 86-03. In addition, a number of check valves were noted to be located immediately downstream of pumps or other turbulence i generators. It was also noted that the vast majority of the maintenance performed was corrective, as opposed to preventive maintenanc gDR ADOCK O g5

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DETAILS PERSONS CONTACTED C. Bloyd, Technical Services J. Fisicaro, Licensing J. Friedricksen, Technical Services D. Golden P. Harrell, NRC Senior Resident '

D. Hendry, OPPD R. Kellog, Supervitor, Mechanical Technical Services M. Klonderud, OPPD L. Kusek, OPPD K. Miller, OPPD R. Mueller, OPPD Plant Engineering D. Munderloh, OPPD Licensing The inspectors also held discussions with other licensee employees during the inspectio Everyone listed above was present at the exit meeting on August 21, 1987. SCOPE The licensee's programs for testing, inspecting, and maintaining check valves were reviewed to determine the adequacy of the programs to ensure disk and seat integrity. The licensee's response to INP0's SOER 86-03, concerning check valves, was also reviewe . LICENSEE ACTION ON PREVI0llSLY IDENTIFIED PROBLEMS Problems that had been identified previously were not addressed during the inspectio . REVIEW 0F CHECK VALVES

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4.1 Component Cooling Check valves AC-101, AC-104, and AC-107 are the component cooling pump discharge check valves. All three valves are located downstream of a 90 elbow that is attached to the pump discharge and upstream of an isolation valve and a 90 elbow. The valves are tested for passing flow only under the pump test procedure ST-ISI-CC3. The acceptance criterion for opening is that pump discharge pressu,re is less than 120 psig. The pump test curve has a 2000-gpm acceptance ban The valves are not tested for closure, although such testing would appear to be required by Section XI for valves that are both open and closed during normal plant operations (0 pen Item 50-285/87-22-03).

The review of maintenance orders (M0s) indicated that all three valves had required corrective maintenance. MO 10899 was written on July 15, 1981 because check valve AC-101 failed to close and the pump ran in revers l l - -

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Inspection revealed that the flapper arm was bent. M0 830044 was written on November 3, 1983 because check valve AC-104 was making nois However, the M0 l was cancelled because there were no parts available to perform maintenance, j No work has been done on the valve since MO 830044 was cancelled (0 pen Item 50-285/87-22-02). M0s 851981 and 855175 were written in June 1985 because-check valve AC-107 was making noise. After taking the valve apart and l inspecting it, no damage was foun '

4.2 Raw Water Raw water (RW) check valves RW-115, RW-117, RW-121, and RW-125 are the discharge check valves for the raw water pumps. The valves are located downstream of 90 elbows that are attached to the pump discharges and upstream of isolation valves that are attached to tees. The pumps are tested for forward flow under procedure ST-ISI-RW-3 with an acceptance criterion of pump total dynamic head of 140 psig or less indicating the valves are open. The valves are not tested for closure although such testing would appear to be required by Section XI for valves that are both open and closed during normal plant operations (0 pen Item 50-285/87-22-03). No maintenance involving seat, disk or operability was noted during the period reviewe .3 Containment Sump Suction Check valves SI-159 and SI-160 are located in the containment sump and prevent the reactor water storage tank from draining into the sump. One of these valves is removed and inspected on an alternating basis every five year These valves are located directly downstream of 90' elbows. The inspection of SI-159 on February 14, 1985 recorded the valve's condition as "like new." No

. Other maintenance involving seat, disk or operability was noted during the period reviewe .4 Safety Injection (1) Containment Spray Valves Valves SI-135, SI-143, and SI-149 are the containment spray pump discharge check valves and prevent reverse flow through the idle pumps. The valves are tested for forward flow only, not for closure (0 pen Item 50-285/87-22-03). No maintenance activities involving the seat, disk, or operability were noted

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during the period reviewe Check valve SI-135 is located 3 feet downstream from the pump discharge and immediately upstream of a 90" elbow. Check valves SI-143 and SI-149 are <

located 3 feet downstream of the pump discharges and immediately upstream of 90 and 60* elbow (2) Low-Pressure, Safety Injection Pump Discharge Valves Valves SI-121 and SI-129 are the low pressure, safety-injection (LPSI) pump discharge check valves. The valves are tested for forward flow only; there is no testing for closure (0 pen Item 50-285/87-22-03). Both valves are located 3 feet downstream from the pump discharge and immediately upstream of ! solation valves. For the period reviewed, no maintenance was noted involving the seat, disk, or operabilit _ _ _ - _ _ _

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(3) High-Pressure Safety-Injection Pump Discharge Valves Valves SI-102, SI-108, and SI-115 are the high-pressure, safety-injection (HPSI) pump discharge check valves. The valves are tested for forward flow only; there is no testing for closure (0 pen Item 50-285/87-22-03). The valves are located 2 feet downstream of 90 elbows that are attached to the pump discharges and intnediately upstream of tees that are followed 3 feet q For the period reviewed, no maintenance was noted

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downstream by 90' elbow involving the seat, disk, or operabilit (4) High-Pressure, Safety-Injection Secondary Isolation Valves  !

Valves SI-195, SI-198, SI-201, and SI-204 are the HPSI secondary isolation check i valves. The valves are tested for forward flow during refueling outages and 2 are tested for leaks under Surveillance Test ST-CV-1 during refueling outage These valves were not inspected for location and for the period reviewed, no j maintenance involving the seat, disk, or operability was note (5) Low-Pressure, Safety-Injection Secondary Isolation Valves Valves SI-194, SI-197, SI-200 and SI-203 are the LPSI secondary isolation check valves. These are tested for leaks under Surveillance Test ST-CV-2 and '

are tested for forward flow during refueling outages. These valves were not inspected for location and for the period reviewed, no maintenance involving the seat, disk, or operability was note (6) Primary Isolation Valves Valves SI-208, SI-212, SI-216 and SI-220 are the primary pressure isolation check valves between the reactor coolant piping and the lower pressure safety-injection systems. The valves are tested for forward flow and for leak Th se valves were not inspected for location and for the period reviewed, no I maintenance involving the seat, disk, or operability was note i l

4.5 Main Steam (1) Main Steam Isolation Check Valves Valves HCV-1041A and HCV-1042A are the power-operated main steam isolation check valves installed in the 24-inch main steam line. These valves close on

a two-out-of four logic, steam generator isolation signal (SGIS) so that the steam generators can be isolated automatically to prevent their blowdown in the event of a main steam line break (MSLB) inside containment. The licensee a stated that the leak rates of the valves are determined during refueling outages and after certain types of maintenance are performed on the valves per the inservice inspection procedure No. ST-151-MS-1. In reviewing the main-tenance procedure, MP-MSIV-1, the inspector noted the post-maintenance test procedure referenced is ST-ISI-MS-1. However, ST-ISI-MS-1 does not provide instructions for testing these valves (0 pen Item 50-285/87-22-01). The NRC inspector reviewed several M0s related to the subject valves dated between March 3, 1984 and June 23, 1987; the inspector was able to verify some documen-tation of leak rate testing for the subject valves. The valves also are tested for forward flow during normal operatio A review of the M0s revealed

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that the subject valves did receive substantially more maintenance than the check valves reviewed in other systems. The increased maintenance was mainly attributed to high steam flow through the valves and packing leak l These valves are located immediately upstream of check valves HCV-1041B and .

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HCV-10428, respectively, and immediately downstream of the main steam safety relief valves, that are immediately downstream of a 90' elbo ;

(2) Main Steam Lirie Check Valves Valves HCV-1041B and HCV-10428 are the main steam line check valves. The licensee stated that these valves are tested for forward flow during normal operations. The subject check valves are not tested for leak rate because of

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an assumption made in the Updated Safety Analysis Report (USAR), Section 14.1 (Method of Analysis) that a single failure of the reverse-flow check valve in the ruptured steam generator is assumed, so that the intact steam generator will have ; team flow through the unaffected steam line and back through and out the ruptured line. The analysis conservatively neglects a choke that is installed in each steam line and assumes the steam will flow from the intact steam generator through an unrestricted 24-inch steam line. The NRC inspector reviewed several maintenance orders dated from March 3, 1984 through July 15, 1986 which documented a number of inservice inspections of the internal components of the valves; however, the maintenance required on the valves was minimal. These valves are immediately downstream of 90 elbows, main steam safety relief valves, and the main steam isolation valves HCV-1041A and HCV-1042A, j respectivel .6 Chemical and Volume Control System Check valves CH-203, CH-204 and CH-205 are located in the charging line, alternative charging line, and common supply line, respectively, between the chirging pumps and reactor coolant piping. Aside from observing unrestricted flow during plant operations, these valves are not included in any test procedure, nor is their proper operation recorded anywhere. The licensee stated that the valves are not tested because they are always experiencing full flow, do not perform an isolation function, and are consistently in the full-open position; therefore, the subject valves are not required to be exercised under the Section XI in-service testing (IST) requirements for check valves in the normally open positio However, the check valve on either the normal or alternate charging ifne should close when the other line is performing the charging function and does isolate the reactor coolant system in the event of a break in either line (0 pen Item 50-285/87-22-03).

These valves were not inspected for locatio Check valve CH-198 is located in a 2-inch line downstream of the three positive displacement charging pumps. The valve is also located just outside the containment, I foot downstream from a 90* elbow and functions to prevent backflow to the charging pump discharge header (an isolation function).

Because the check valve does perform an isolation function, it is required to be exercised under the Section XI IST requirements for valves performing an isolation function. However, ir the IST program submitted for review by the

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licensee, an exemption is requested for check valve CH-19 The exemption j states in part, that back seat testing on reversal of flow or stroke testing of the valve cannot be performed because of piping configuration However, forward flow shall be tested at each refueling outag Check valves CH-187, CH-188, and CH-189 are located in 2-inch lines directly off the positive displacement charging pumps. The check valves are tested for passing flow through the valves during normal operation. The licensee also stated that operating procedures require the charging pumps to be tested in rotation once a week, at which time the check valves are tested to ensure that they close on backflow conditions. However, the procedures and records of test results were not formally documented (0 pen Item 50-285/87-22-03).

A review of maintenance records indicated that no maintenance relevant to disk or seat integrity had been performed on the chemical and volume control system (CVCS) check valves that were reviewe .7 Feedwater System Feedwater (FW) system check valves FW-106, FW-107, and FW-108 are located in 14-inch lines downstream of 90 elbows that are attached to the motor-driven steam generator feed pumps and upstream of an isolation valve that has a 90*

elbow attached on the downstream side. The valves are lift-type check valves and are tested for passing flow during normal operation. The licensee also stated that operating procedures require rotational testing of the feed pumps once a month, at which time the check valves are tested to ensure they close under backflow conditions. However, the procedures for and records of testing were not formally documented (0 pen Item 50-285/87-22-03).

Check valves FW-161 and FW-162 are installed in the two 16-inch main feedwaf.er lines and are located directly upstream of the steam generators. These valves are normally open during operation; to cycle these valves closed would result in a loss of normal feedwater to the steam generator. Then the water level in the steam generator could drop, possibly causing a reactor trip. However, in the IST program that the licensee submitted for NRC review, an exemption is requested for the backflow testing of check valves FW-161 and FW-162. The exemption states,<in part, that since the failure of these valves to function in the backflow direction would not interfere with the plant's ability to shut

. down or mitigate the consequences of an accident, these valves shall only be tested in the forward-flow direction. The exemption further stated that the valves shall be exercised at each cold shutdown or refueling outage, or if more than one cold shutdown or refueling occurs during a 3-month period of time, the valves shall only be exercised once during that 3-month perio These valves were not inspected for locatio Check valves FW-163 and FW-164 are installed in the two 3-inch auxiliary feedwater (AFW) lines located directly upstream of the steam generators. These valves open for AFW flow to the steam generator. Cycling these valves during operation would inject cold water into a portion of the steam generato However, in the IST program that the licensee submitted for NRC review, an exemption is requested for the backflow testing of check valves FW-163 and 164. The exemption states, in part, that since the failure of these valves to function in the backflow direction would not interfere with the plant's

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ability to shut down or mitigate the consequences of an accident, these valves shall only be tested in the forward-flow direction. The exemption further stated, that the valves shall be exercised at each cold shutdown or refueling outage, or if more than one cold shutdown or refueling occurs during a 3-month period of time, the valves shall be exercised once during that 3-month perio These valves were not inspected for locatio Check valve FW-173 is installed in a 4-inch line located directly off the motor-driven AFW pump. The valve is onl exceeding a reactor coolant system loop (RCS)y tested for temperature forward 6f 300'F, per flow before operating procedure OP- The licensee stated that the valve initially was thought to have received a quarterly test for forward flow per surveillance test procedure No. ST-FW-1-1 in which the flow was directed to the emergency feedwater storage tank (EFST). However, it was discovered that when the flow is directed to the EFST, the flow no longer passes through check valve FW-173; therefore, the licensee has requested an exemption for the subject valve in its-latest IST program submitta The valve is located immediately downstream of a 90' elbow and immediately upstream of a tee, 90* elbow, and an isolation valv Check valve FW-1334 is installed in a 4-inch line that provides AFid to the steam generators via the normal feedwater flowpath. On May 23, 1987, the licensee issued a maintenance order to check the leakage rate through the check valve. The valve was determined to be functional. The licensee stated that the test was performed as part of its response to INPO SOER 86-03 which identified some operational problems with check valves supplied by the manu-facturer, Pacific Valves. The licensee further stated that it does not consider check valve FW-1334 to be a critical valve in the AFW system and that the valve is normally tested only for passing flow before exceeding an RCS loop temperature of 300' A review of maintenance records indicated that no maintenance relevant to disk or seat integrity had b o n performed on the feedwater valves that were reviewe .8 Auxiliary Feedwater Pump Check Valves Check valves MS-351 and MS-352 are installed in the 2-inch steam supply lines to the steam-driven AFW pum If these valves failed to perform their backseat function in the event of a steam line break (in the supply line), no steam would be supplied to the AFW pump. The licensee stated that the valves are not tested for backflow conditions, only for passing flow (0 pen Item 50-285/

87-22-03). A review of the M0s did reveal some inservice inspection of the internal components of the valves and a minimum of required maintenanc I Check valve MS-351 was located 3 feet downstream of two 90* elbows and 2 feet upstream of a tee. Check valve MS-352 was located 2 feet upstream of a te .9 Diesel Generator Air Start System Check Valves Check valves SA-137, SA-138, and SA-188 are installed in 3/4-inch lines located directly downstream of the emergency diesel generator (EDG) starting air compressors. The valves' function is to keep air from leakirig from the

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four EDG air start receivers. The licensee stated that the valves are only tested for forward air flow through the valves during normal operation and ,

that the air piping and compressors upstream of the valves are seismically ]

qualified. A review of the maintenance records indicated that no maintenance of interest had been performed during the time period reviewed. Valves SA-137 and SA-138 are installed between two 90' elbow i' SOER Resp 0NSE At the time of the inspection, the licensee's response to the SOER consisted of a four-page internal memorandum dated December 16, 1986. restating the 50ER guidelines and outlining planned actions. The licensee had started, but had not completed, a review of valve location, valve maintenance history, and valve size. The licensee plans to complete this review by February 1988 and to determine by that date which valves should be included in a preventive maintenance (PM) program. The licensee did not intend to start developing the PM program until meeting the February 1988 commitmen . EXIT MEETING The inspectors met with the licensee's representatives listed in Section 1 on August 20, 1987, and presented the findings of this inspectio .

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