IR 05000261/1988012
| ML14191A951 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 06/30/1988 |
| From: | Blake J, Kleinsorge W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14191A950 | List: |
| References | |
| 50-261-88-12, NUDOCS 8807250322 | |
| Download: ML14191A951 (13) | |
Text
pk REGj4 -UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report No.:
50-261/88-12 Licensee: Carolina Power and Light Company P. 0. Box 1551 Raleigh, NC 27602 Docket No.: -50-261 License No.:
DPR-23 Facility Name: H. B. Ro inson Inspection Co d-10 1988 Inspector:
or Approved b J. ke, Chief DreSge to als and Process Section ngi eering Branch Division of Reactor Safety SUMMARY Scope:
This routine, unannounced inspection was conducted in the areas of Verification of Compliance with Order Modification of License:
Primary Coolant System Pressure Isolation (Event V) Valves (TI-2515/84) Inservice Testing (IST) of Pumps and Valves (73756)
and Service Water Piping Degradation (92706B)
Results: In the areas inspected, no violations or deviations were identifie There appears to be a weakness in the areas of management involvement in assuring quality and resolution of technical issues from a safety standpoint, in that the licensee failed to formally document the engineering evaluation of the justification for continued operation after the identification of possible compromise of containment and an extreme reluctance to commit to planned and scheduled pipe replace ment to permanently correct the problem (Paragraph 4).
One unresolved item was identified involving the adequacy of forward flow testing of check valve seo725o322 S0707 P807A3 P05000N QPDR P tu
REPORT DETAILS 1. Persons Contacted Licensee Employees
- J. Curley, Acting General Manager
- Dayton, Project Engineer/Technical Support
- S. McCutcweon, Inservice Inspection (ISI)
- Pruitt, ISI Coordinator
Other licensee employees contacted during this inspection included craftsmen, engineers, operators, technicians, and administrative personne NRC Resident Inspectors L. Garner, Senior Resident Inspection (SRI)
- Latta, RI
- Attended exit interview Verification of Compliance with Order for Modification of License:
Primary Coolant System Pressure Isolation (Event V) Valves. (TI 2515/84)
a. Background The Reactor Safety Study (RSS),
WASH-1400, identified in a PWR an intersystem Loss of Coolant Accident (LOCA)
that is a significant contributor to risk of core melt accidents (Event V).
The design examined in the RSS contained in-series check valves isolation the high pressure Primary Coolant System (PCS)
from the Low Pressure Injection System (LPIS)
pipin The scenario which leads to the Event V accident is initiated by the failure of these check valves to function as a pressure isolation barrier against Reactor Coolant System (RCS) pressure. This causes an overpressurization and rupture of the LPIS low pressure piping which results in a LOCA outside of the containmen To better define the Event V, all light water reactor licensees were requested by letter, dated February 23, 1980, to provide system design information in accordance with 10 CFR 50.54(f).
Based on licensee responses, it was concluded that a valve configuration of concern existed at 36 plant On April 20, 1981, an order requiring Event V valves testing was sent to 32 PWR plants and two BWR plant This order included a Safety Evaluation Report (SER) and Technical Specification inserted pages to require leak rate testing of Event V pressure isolation valve The two additional plants had previously been issued a licensee amendmen b. Inspection The inspector reviewed documentation associated with the implemen tation of the Event V order from 1980 to present to evaluate compliance. The specific areas examined are indicated belo (1) The inspector reviewed selected records to verify that test data reflected all requirements specified in the Technical Specification (TS)
including the following:
test records contain major test data including upstream and downstream pressures, leak volume per unit time (or equivalent), leakage rate adjustment calculations when required, and leakage rate acceptance criteria based on trending from previous tests where applicable; recorded test frequency is in accordance with TS; as found leakage is recorded; leakage rate trending has been
£ documented and adequately evaluated by the licensee in accordance with the TS requirement; no test data anomalies exist which indicate improper or inaccurate testing and; adequate corrective actions were taken for valves not meeting the acceptance criteri (2) Additional inspections in this area are discussed in NRC Report Nos. 50-261/87-35 (Paragraph 5) and 50-261/88-04 (Paragraph 6b).
Within the areas examined no violations or deviations were identifie. Inservice Testing (IST) of Pumps and Valves (73756)
The inspector reviewed procedures, observed work activities and reviewed pertinent quality records, as indicated below, to determine whether inservice testing regulatory requirements and licensee commitments are being met. The applicable code for IST of pumps and valves is ASME Boiler and Pressure (ASME B&PV) Code Section XI 1977 Edition Summer 1978 Addenda (77578).
a. Pump Testing Pump Records Examined Containment Spray Pump A & B Safety Injection Pump AB & C Service Water Pump A & 8 RHR Pump A & B Boric Acid Transfer Pump A & B
Procedures Examined Identification Title OST-108,
"Boric Acid Pumps Inservice Rev. 14 Inspection (monthly)"
OST-151,
"Safety Injection System Rev. 25 Component Test (monthly)"
OST-251,
"RHR Component Test (monthly)"
OST-302,
"Service Water System Rev. 20 Component Test (monthly)"
OST-352
"Containment Spray System Rev. 17 Component Test (monthly)"
EST-005,
"Safety Injection Pump Bearing Rev. 3 Temperature Test Annual'
EST-007
"Containment Spray Pump Rev. 2 Bearing Temperature Test (Annual)
EST-089,
"Residual Heat Removal Pump Rev. 0 Bearing Temperature Test (Annual)
(1) The inspector reviewed the last six completed test procedures for the above listed pumps for the following attribute:
(a) To verify that these procedures were the latest ones approved and that test acceptance criteria used were valid for the component being teste (b)
To verify that the licensee performed IST per an approved schedule within the limitations described in the IST program, including increased frequency testin (c)
To verify that inservice test results were recorded per the approved procedures and that data was evaluated within the time constraints delineated in the appropriate edition of the ASME Code Section XI, Subsection IW (2) The inspector reviewed the above identified procedures to ensure that IST procedures and data reflect all requirements of the appropriate edition of the ASME Code Section XI, including:
evaluations of imposing and removing increased frequency testing requirements; evaluation and justification of changes to test acceptance criteria; pump vibration test data analysis and acceptance criteria justification, including location of
vibration measurement; requirements that pump tests be conducted at reference conditions, including reference speed; and compliance of test instruments to 10 CFR 50 and ASME Code requirement (3) The inspector examined the test data for the six most recent tests for the above pumps, to verify that IST data are evaluated per the requirements of ASME Code Section XI, Subsections IWP and IWV, and 10 CFR 50.55a(g) and that appropriate followup actions are take (4) The inspector reviewed selected IST records to verify that IST records are maintained as delineated in ASME IWP-6000 and IWV-6000 and Engineering evaluations justify changes to reference values and removal of increased frequency testing requirement (5) The inspector made the following observations relative to the above examination of pump testing:
(a) The Nuclear Regulatory Commission's (NRC's)
Office of Nuclear Reactor Regulatory (NRR)
identified several item which required additional information regarding the H. Robinson Steam Electric Plant Unit No. 2 (HBR2)
Second Ten-Year Interval In-Service iesting Program. These items were identified in a meeting with the NRC staff on November 10, 1987, and a subsequent telephone conversatio Among these items was the testing of the containment spray pumps. After further consideration of the discussion during the November 10, 1987, meeting and the physical arrangement of the plant, the licensee generated a relief request, in a March 8, 1988, letter to the commission. The licensee committed to the following in their March 8, 1988, submittal:
"The procedure revisions necessary to perform the testing listed above will be in place on or before June 1, 1988. The appropriate IST Program Relief Requests will be submitted on or before April 15, 1988."
The March 8, 1988, -submittal contained the following Note:
these proposed tests will not be performed at maximum flow, however, flow rates will be chosen to give confidence that operational flow requirements will be met."
Pursuant to the March 8, 1988, letter the IST surveillance test (OST-352) for the Containment Spray Pumps (CSP)
was modified such that a different flow path was used which allow monitoring flow in addition to differential pressur On performing this revised test (Revision 16), the vibration amplitude of the A-CSP exceeded the test acceptance criteria. Additional evaluation confirmed that the vibration was a result of the increased restriction of
the one-inch recirculation flow path used in Revision 16 as compared to the two-inch flow path used in previous testing (Revision 15) and not a problem with actual pump operatio Licensee consultation with the pump vendor, Ingersall/Rand (IR),
revealed that the vibration experienced during the revised test exceeded the recommended vibration for continuous operation. Therefore, testing the pumps using this procedure could represent a operability concer In a June 3, 1988, letter to the Commission, the licensee requested NRC approval for withdrawal of their commitment date of June 1, 1988, to begin flow rate monitorin The licensee committed, in their June 3, 1988 submittal, to provide within 45 days a plan and schedule for implemen tation of flow monitoring during in-service testing of the CSP In the interim, until flow monitoring can be implemented, they will to continue to perform the previous in-service testing procedure which monitors all of the the Table IWP-3100-1 parameters except flow rate, This procedure will be implemented as Revision 1 (b) The ASME 8&PV Code Section XI Paragraph IWP 3500(b)
and, Procedure Nos EST-005, EST-007 and EST-089 require that each pump shall be run until the bearing temperatures stabi ize, and then the quantities specified shall be measured or observed and recorde A bearing temperature shall be considered stable when three successive readings taken at ten minutes intervals do not vary by more than 3%.
In addition the three EST's impose an addition restriction in that the pumps may only be run for 30 minute The licensee stated that the 30 minutes restriction is based on the pump manufacturer's recommendation that pump not be allowed to run in the recirculation mode longer than 30 minute For the containment spray and safety injection pump, "stability" was not achieved within the 30 minutes time limit. The licensee has requested relief from this requirement for reasons other than the operability concerns indicated above. The following is the text of the basis for their relief request. "The referenced Edition of the Code requires bearing temperature to be recorded annuall The detection of possible bearing failure by a yearly temperature measurement is highly unlikely. It requires at least an hour of pump operation to achieve stable bearing temperature The small probability of detection of bearing failure by temperature measurement dose not justify the additional pump operation time required to obtain the measurement The vibration measurement performed during quarterly intervals will provide better indication of
impending bearing failure than an annual bearing temperature measuremen A review of historical bearing temperature data collected bears this out."
(c) Review of the specific values for Inservice Test Quantities allowable range acceptance criteria listed in the various IST procedures compared with the range criteria specified in Table IWP-3100-2, indicated that the licensee does not have a consistent method of rounding off values and that in some cases values are not rounded off or up in the conservation directio (d) Review of IST records indicated that the licensee has no policy for the number of significant figure In the case of the safety injection pumps, the calculation of differential pressure involves, among other factors, the level of the refueling water storage tank expressed in percent. This value is taken from an instrument in the control room which will provide data with only two significant figure accuracy. Calculations made,with this value are listed on pump test records with eight signifi cant figures. More than three in this case are meaningless and mis eadin Valve Testing As a result of concerns identified at Florida Power and Light's, Turkey Point Site, this inspector reviewed the forward flow testing of Check Valves SI-875A, SI 875C, SI 876A and SI 876C, required by ASME B&PV Code Section XI Subsection IW ASME B&PV Code Section XI Paragraph IWV 3522 requires that check valves be exercised to the position required to fulfill their safety function. The NRC position, for the testing of normally closed check valves, is a articulated in NRC memorandum from D. G. Eisenhut, Director, Division of Licensing, Office of Nuclear Reactors Regulation (NRR) to C. E. Norelius, Director, Division of Engineering and Technical Programs, Region III dated January 3, 198 This memorandum provides the following listing of test methods which are acceptable for any check valve in which the full stroke motion of the disc cannot be directly observed or where there is not position indicating device. These four methods are currently being accepted in IST program review By demonstrating that the valve can pass the full flow which has been taken credit for in FSAR analyse By showing that, for the measured flow, the pressure loss through the valve is such that the valve could only be fully ope By using a mechanical exerciser which can be observed to move through a full strok By partial disassembly of the valve and manually moving the disc through a full strok The above stroking tests assure that the valve is exercised at least to the position required to fulfill its function and, therefore, the intent of ASME Section XI requirements are me The licensee uses operations surveillance test Procedure OSI-255 Revision 2, "RHR and SI System Check Valve Test (Refueling Interval)"
to satisfy this requirement. The test is accomplished by operating both RHR Pumps (See Attachment 1) passing flow through flow element FE 605, through valve RHR-744A (Valves RHR-744B and SI-885 closed)
splitting into two possible pathes (Path No. 1 Via Valves SI 876A and SI-875A, Path No. 2 via valves SI-876C and SI-875C).
The test is considered satisfactory if indicated flow is greater than 2160 Gallons Per Minute (GPM)
as indicated on flow indicator FI-605 associated with flow element FE-60 In a similar test,, valves SI-875B and SI-876B are tested by running one RHR Pump passing flow through flow element FE-605, RHR 7448, SI-876B and SI-875B (with valves RHR-744A and SI-885 closed), with flow reading taken at FI-605. It appears that the three flow patches are hydraulically similar (flowpath one
-
FE 605 to SI-875A via RHR 744A and SI-876A, flowpath two -
FE-605 to SI-875C via RHR-744A and SI-876C, and flowpath three - FE-605 to SI 8758 via RHR-744B and SI 876B).
During the last performance of OST-255, path three exhibited a flow of 3500 GP In view of the above there is a strong likelyhood that if flowpath three can pass 3500 GPM then either path one or path two singularly could pass 2160 GPM. If this is the case, then the licensee has not demonstrated:
that valves SI 875A, SI 876A, SI-875C and SI-876C can pass the full flow which has been taken credit for in the Final Safety Analysis Report (FSAR); or that the valves fully ope The inspector informed the licensee that this matter would be identified as Unresolved Item 50-261/88-12-01; "Adequacy of Forward Flow Testing of Check Valves."
Within the areas examined no violations or deviations were identifie. Service Water Piping Degradation (927068)
Background The degradation of the service water system is described in RH Report N /84-45. Additional inspection in this area is reported in RH Report No /84-48, 261/85-12, 261/85-22, 261/86-12, 261/87-03, 261/87-16, 261/87-35 and 261/88-0 This information is a continuation of the inspection described in the above report In CP&L letter RESP/84-1267, dated January 4, 1985, the licensee committed to an inservice monitoring program to include 15 service water welds that would represent a variety of configurations, lengths or corrosion (microbiological induced corrosion (MIC)' and sleeved as well as non sleeved joint These joints were to be radiographed (baseline) prior to start up and re-radiographed (inservice monitoring) in six weeks +/- one week. Should no further :attack be identified, the next radiographic examination would be scheduled three months +/- two weeks late The licensee radiographed 15 weld joint (baseline) on December 12, 1984, (except for Weld 2503-02 radiographed on November 19, 1984),
re radiographed the same 15 weld joints on February 26, 1985, and re-radiographed the same 15 weld joints between May 31, 1985, and June 14, 1985. In addition, two more Welds 3-503-3 and 3-503-5 were added to the sampl The same sample of 17 welds were re-radiographed during the period of October 29 - November 4, 1985, and the results reported to the NRC by CP&L letter RNPD/96-124, dated January 31, 198 The inspector reviewed a sample of six of the radiographs (inservice monitoring) made late in 1985, and compared them with baseline radiographs made in late ir, 1984. The inspectors reviewed the radiographs to determine whether there had been any corrosion growth between the baseline radiographs of December 28, 1984, and the (inservice monitoring)
radiographs of October 29 - November 4, 198 The inspectors noted that the licensee's radiographic technique had changed sinsectorst tnservice monitoring radiographs of June 198 This change caused distortion resulting from geometric unsharpnes This distortion made it extremely difficult to determine corrosion indication enlargement. In view of this, the inspector discussed the matter with the licensee and made some recommendations for improvemen The licensee implemented the inspector recommendations in their December 8-12, 1986, radiographic examination of the service water system sampl This examination detected new indications and apparent further growth of the Microorganism Induced Corrosion (MIC).
This radiographic examination indicated that six of the 15 sleeved welds sampled in containment and in the auxiliary building exhibit apparent new growth in the sleeve-to-pipe fillet weld heat affected zon The results of the December examination were reported to NRC Region II by CP&L letter dated January 16, 198 All the six-inch welds in the containment have been sleeved. The licensee has determined that the growth rate of the indications is conservatively estimated as approximately 5/8-inch circumferentiall The licensee has reviewed all past radiographs for the non-sleeved welds in the auxiliary buildin They have identified 17 welds which, given the 5/8-inch circumferential growth rate, would exceed the five inch structural limit
by the 1988 refueling outage. Those 17 welds have been sleeve During the 1987 outage, the licensee has completed a chemical treatment intended to remove the biological based fouling from the service water system. This treatment consisted of a temporary recirculation/flushing loop established with each individual cooler unit and its pipin A combination of a biodispersant and biocide was recirculated in the loop to clean the system's interior wall areas followed by a flushing with service water. After completion of treatment with biodispersant/biocide, the system was cleaned with a hydrogen peroxide solution (<3%),
to further break up interior fouling and kill microorganisms, and flushe When treatment was completed, each cooler unit piping was restored, tested, and returned to servic The chemical treatment process was implemented during the last five days of the 1987 refueling outag Due to time constraints and problems with equipment, each HVH loop was treated for only 1-4 hours instead of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> as originally schedule The biodispersant dislodged some brown material in the system, but did not remove the bulk of the black foulin The fouling was approximately 1/8-inch thick, and had an apparently different composition than other fouling found elsewhere in the service water system. The Harris E&E Center Analytical Chemistry Unit and Buckman Laboratories (who provided the biocide/dispersant) are both currently have analyzed the foulin The HVH 4 loop was treated for the longest perio of time (4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />), and a visual inspection of the piping revealed that the fouling was removed in high velocity areas (i.e.,
in elbows).
This observation indicates that the dispersant is effective in cleaning the pipes, but requires more recirculation time to ensure complete cleanin Samples of water before and after treatment with dispersant and biocide were taken by the Buckman Laboratories representative to determine biological activit A culture sample of untreated service water indicated 60 microorganism; the same size culture sample for the treated water indicated over 60,000 microorganism The one thousand fold increase in microbes is a positive indication that the dispersant and pump were highly effective in removing some of the bacteri However, the low level dose of biocide was not as effective in digesting the organism. The licensee indicated that a biocide is needed that will kill these organisms so that the count in a water sample will approach zer Samples of the fouling were tested by the Harris E&E Center's Chemistry Unit and by Buckman Laboratories and were found to have the following analysis:
MnO 37%
Fe 3 11%
Si0 3%
Al263 8%
Organic Content 41%
Results from a regularly scheduled radiographic examination in October 1986, indicated sleeved welds sampled in containment and the auxiliary building exhibited new growth in the sleeve-to-pipe fillet weld heat affected zone. This information was presented to the commission by
letter in January 198 A September 1987, letter to the commission also addressed MIC growth in the sleeve-to-pipe fillet weld heat affected zone observed during May and June 1987, radiograph The most recent radiographs from April 1988, indicate that of the 41 welds examined, eight have indications of MIC growth in the pressure boundar These indications raise a possible containment integrity concer Structural integrity of the service water pipe is not in questio The welds reported in 1987 by the licensee to have MIC in the fillet weld heat affected zone and examined by this inspector exhibited MIC totally within the envelope of the sleevin The MIC observed during this examination in radiographs made in spring 1988 was in the pipe wall outside of the envelope of the sleeve The inspector discussed the above with the licensee who indicated that they had evaulated the possible containment integrity concern and determined it not to be a proble Further, the licensee indicated that they intended to replace some Service Water pipe in the containment during the November 1988, refueling outag After further discussion the licensee provided the inspector with a preliminary copy of an engineering evaluation, written as the result of the inspectors concerns, providing justification for continued plant operatio The inspector informed the licensee that he perceived a weakness relating to management involvement in assuring quality and resolution of technical issues from a safety standpoint in that the licensee identified a possible compromise of containment integrity and had not documented a formal engineering evaluation to support continued operatio In addition the licensee has planned for pipe replacement during the fall 88 refueling outage but the licensee was reluctant to formally commit to pipe replacemen Within the areas inspected no violations are deviations were identifie. Action on Previous Inspection Findings (92701)
-
(Open)
Inspector Followup Item 50-261/84-45-01:
"Service Water Degradation" This matter was further examined during this inspection and is discussed in Paragraph 4 of this report. This item remains ope (Open)
Inspector Followup Item (IFI) 50-261/87-16-01:
"MT Procedure Discrepancies" The licensee was not prepared to discuss this matte This matter remain open
-
(Open)
Inspector Followup Item 50-261/87-16-02:
"ISI Replacement Verification of Acceptability"
The licensee was not prepared to discuss this matte This matter remains ope (Closed)
Inspector Followup Item 50-261/87-35-01:
"Event V Order OQE" The licenses provided the inspector with the necessary Objective Quality Evidence (OQE). This matter is considered close. Exit Interview The inspection scope and results were summarized on June 10, 1988, with those persons indicated in paragraph The inspectors described the areas inspected and discussed in detail the inspection results listed belo Proprietary information is not contained in this repor Dissenting comments were not received from the license Item No. 50 261/88-12-01: Unresolved Item - Adequacy at Forward Flow V Testing of Check Valve The licensee management was informed that four inspectors followup items were examined and one was close.
The licensee management was informed of the inspectors perception of a weakness in management involvement in assuring quality and resolution of technical issues from a safety standpoin The licensee concurred with the inspectors concern over the issue of no documented engineering evaluation for justification of continued operativ The licensee s managements representative disagreed with the issue of non commitment to replace pipe, indicating that the replacement is scheduled and planne Therefore the licensee's management stated; we are involved."
When asked again whether this should be construed as a commitment, the answer was n Attachment 1
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