IR 05000133/1998001
| ML20203K978 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 02/27/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20203K973 | List: |
| References | |
| 50-133-98-01, 50-133-98-1, NUDOCS 9803050294 | |
| Download: ML20203K978 (16) | |
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ENCLOSURE U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
Docket No.:
50 133 License No.:
DPR 7 Report No.:
50-133/98-01 Licensee:
Pacific Gas and Electric Company (PG&E)
Facility:
Humboldt Bay Power Plant Unit No. 3 i
Location:
1000 King Salmon Avenue Eureka, Califomia 95503 Dates:
January 26 - 29,1998 Inspert 1:
J. V. Everett, Health Physics Inspector L. L. Wheeler, NRR Project Manager R. F. Dudley, NRR Project Manager Approved By:
D. Blair Spitzberg, Ph.D., Chief Nuclear Materials Safety Branch 2 Attachment:
Supplemental Informatior 9903050294 900227 PDR ADOCK 05000133.
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EXECUTIVE SUMMARY Humboldt Bay Power Plant. Unit No. 3
NRC Inspection Repcrt 50133/98-01 Humboldt Bay has been in a SAFSTOR decommissioning status since 1976. The facility was
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being maintained in an acceptable structural condition and appeared in relatively gocd condition with no significant deterioration or structural problems.
The most challenging problem that had been ongoing at the Humboldt Bay facility for the past several years involved a groundwater in-leakage problem in the caisson sump. Groundwater had been leaking into the basement of the caisson since 1992. The leak gradually increased from 200 gallons / day in 1992 to a peak of 10,000 gallons / day in late 1996, then stabilized at
- 6,500 to 7,000 gallons / day during 1997.- The licensee repaired the leaks in the caisson basemat
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concrete and in September 1997 reduced the leak to 15 gallons / day, where it had remained steady for the past 4 months. The caisson in-leakage problem now appears to be repaired.
The licensee continued to main' ain good oversight of Unit No. 3. Required technical specification surveillences werr being conducted and the licensee's staff was maintaining an alert attitude toward potential uroblems with Unit No. 3. Staffing appeared adequate for a SAFSTOR condition and ont sing attention by PG&E corporate staff plus support from Diablo
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Canyon appeared excellent.
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Organization. Management. and Cost Controls
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approved SAFSTOR Decommissioning Plan (Section 1).
PG&E was found to be in compliance with the Technical Specifications related to
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quarterly refueling buildhg inspections, refueling building vent system tests, reactor
caisson sump month?y sampling, plant review committee, and site emergency planning
related to conducting un annual exercise (Section 1).-
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The 1997 annual exercise was conducted November 14,'1997. All oojectives of the
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exercise were determined to have been successfully met by the licensee (Section 1).
The licensee had an effective procedural process in place to review generic documents
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issued by the NRC to determine their applicability to the Humboldt Bay site (Section 1).
PG&E had established a task force to evaluate the impact of the year 2000 issue for
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computer software. Humboldt Bay was interfacing with the PG&E task force concerning
specific site computer systems (Section 1)c
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3-Safety Reviews. Desian Chances. and Modifications Acceptable programs were being implemented to ensure that activities, changes, tests,
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and experiments were properly evaluated for compliance with NRC requirements in 10 CFR 50.59 and that no unreviewed safety questions were involved with such activities (Section 2).
Soent Fuel Pool Safety The spent fuel pool cover was removed during this inspection to allow for a visual
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examination of the water clarity and spent fuel condition. Water clarity was very good.
Visual observation of the fuel and the inside of the spent fuel pool indicated that the spent fuel was being properly stored (Section 3).
Spent fuel pool water chemistry, pool water level, and liner gap water level were
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reviewed during this inspection and were found to be within required Technical Specifications (Section 3).
Cold WeathetPreoarations No significant potential freezing problems had been identified for the spent fuel pool and
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associated systems. Commitments made by PG&E in 1994 conceming valve positions for two spent fuel pool water drain lines were confirmed as still being included in the sealed valve list and required to be maintained closed (Section 4).
Decommissionino Performance and Status Review The Humboldt Bay facility was being maintained in a SAFSTOR condition in accordance
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with the approved Decommissioning Plan (Section 5).
The repair of the caisson groundwater in-leakage appeared to have been successful.
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The repair was completed approximately 4 months prior to the inspection. Since the repairs were completed, the rate of in-leakage had remained negligible (Section 5).
Radioactive Waste Treatment. Effluent and Environmental Monitorino Tritium had been historically detected in very low levels in one of the monitoring wells
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onsite. The August 1997 sampling results indicated tritium in a second well that had not historically shown tritium. The licensee was in the process of evaluating this new data (Section 6).
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-4 Henort Detans Summarv of Plant Status The Humboldt Bay Power Plant, Unit No. 3 had been shutdown and placed in a SAFSTOR
decommissioning status since 1976. A Decommissioning Plan was approved by the NRC in 1988. The facihty had remained in SAFSTOR with ongoing maintenance activities associated with keeping needed plant systems operational, such as lighting, building ventilation, security systems, and water systems for the spent fuel pool, The facility was found to be in an acceptable structural condition during this inspection. The in-leakage problem in the caisson basement, which was repaired in 1997, continued to show minimal leakage indicatirig that the problem was successfully repaired. Work planning for removal of the 250-foot vent stack was underway with tentative plans for the stack removal to be completed in 1998. Development of an update to the Post-Shutdown Decommissioning Activities Report (PSDAR) was underway, with issuance planned during the first quarter of 1998. This update will focus on the partial dismantlement activities associated with removal of the 250-foot vent stack.
Organization, Management, and Cost Controls (36801)
1.1 Insoection Scoce Selected Technical Specifications, results of the 1997 annual exercise, decommissioning plans and schedules, and the licensee's process for evaluating generic letters and information notices issued by the NRC were evaluated.
1.2 Observations and Findinas lhe Humboldt Gay facility was in a SAFSTOR decommissioning status. The facility was maintained in a safe condition through scheduled surveillences and periodic minor repair activities. The approved Decommissioning Plan described plant conditions consistent with the current status of the facility. The licensee was developing updates to the PSDAR for submittal to NRC to replace the current Decommissioning Plan. The PSDAR would be more consistent with the format specified in the new decommissioning rule.
A number of Technical Specifications for the Humboldt Bay facildy were reviewed during this inspection. PG&E was found to be in compliance with the Technical Specifications reviewed including quarterly refueling building inspections, refueling building vent system tests, reactor caisson sump monthly sampling, plant review committee, and site emergency planning related conducting an annual exercise.
Technical Specification Ill.B.1 required a quarterly visualinspection of the refueling building. Humboldt Bay Procedure STP 3.7.2," Quarterly Refueling Building Visual inspection and Evaluation,' Revision 35, established the requirements for the quarterly inspection of the refueling building. This procedure provided specific information related to the areas of the building to be examined. Visualinspections included assessments for structural defet n moisture, and structural deterioration. A report was issued after each
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5-insNction. A review was completed of the reports issued for March 11, June 2, August 7, and Octe ber 21,1997. Areas specifically described in these reports as being visutlly inspected ir;cluded the interior above ground structure, access shaft, escape shaft, new fuel storage vault, turbine building drain tank vault, exterior above grade structure, building roc f and spent fuel pool west wall. Some rust on roof trusses was noted. The August 7,1997 rooort noted that no damage was found due to the August 6, 1997, c erthquake.
Technical Specification Ill.B.3 fequired a neutron absorber surveillance program for verifying Boron-10 loading in the spent fuel pool racks. This program was documented in Procedure STP 3.6.4, " Spent Fuel Pool Neutron Absorber Surveillance Program,"
Revision 31, Samples of neutron absorbing material used to fabricate the spent fuel assembly containers had been auspended in the spent fuel pool in the vicinity of the spent fuel assemblies. Si,mples were removed at selected intervalo and analyzed to verify the Boron-10 loading was greater than 0.005 grams /cnf. The intervals specified in the procedure were 1988,1993,1998,2006, and 2016. The 1998 sample will be analyzed this year. Review of the results of the analysis will be included in a future inspection (inspection Followup item (IFil 50-133/98001-01).
Technica! Specification IV.B.1.b required the refueling building ventilation system to be tested at least quarterly. Humboldt Bay Procedure STP 3.7.1, " Quarterly Refueling Building Ventilation System Test," Revision 40, establisned the program for conducting the tests. Records were reviewed for 1997. The ventilatior system tests had been appropriately conducted and at a frequency greater than required.
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Technical Specification VI.B.1.c required monthly sampling and analysis of the reactor caisson sump for alpha beta, and gamma radiation. Humboldt Ray Procedure STP 3.21.5, "Me thly Caisson Sump Sampling," Revision 36, established the program for conducting sar.pling and analysis of the caisson sump water. The monthly records for January through December 1997 were reviewed. The caisson in-leakage
problem had been repaired in September 1997. Results of the caisson sampling had not shown a significant change in the c, icentration of radionuclides in the caisson sump water related to the repair of the leak. The levels for cesium-137 (Cs-137) and cobalt-60 (Co-60) continued to be below the lower level of detection limits specified in NUREG 302, "Offsite Dose Calculation Manual Guidance: Standard Radiologica!
Effluent Controls for BWRs," Table 4.11-1, or below 5 X 104 uCi/ml.
Technical Specification Vll.D.1 established the requirements for a plant staff review committee. The January 29,1998, committee meeting was attended by the NRC inspector. The licensee attendees included the plant manager, operations manager, maintenance manager, quality control supervisor, licensing manager, and senior radiation protection engineer. Technical Specification Vll.D.1.e required a forum of four members from the positions listed in Technical Specification Vll.D.1.b. The attendees met the minimum requirement for a quorum. A number of plant activities and open items were discussed including the status of nonconformances, department radiological exposure estimates, and a number of recently issued NRC information notices.
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Technical Specification Vll.F required the licensee to maintain a site emergency plan and to perform drills and exercises as described in the emergency plan. The Humboldt Bay Emergency Plan, Revision 26, Section 8.1.3.1, required an annual emergency drill for the site. On November 14,1997, a site wide drill was successfully conducted to comply with the requirement in the emerger'cy plan. The scenario involved the Unit No. 3 ventilation stack falling through the reactor fuel building roof and into the spent fuel pool, crushing the equivalent oi 12 Sel assemblies. The noble gas, krypton-85, was released from the fuel assemblies, ivith 20 percent going through the new stack and 80 percent going out the hole in the reactor fuel building. Two contract personnel also fell through the hole in
the roof and were severely injured. Exposure rates inside the reactor fuel building were 10-20 milliioentgen per hour (mR/hr). Dose rates at the fence line were 0.6 mR/hr The scenario selected for this exercise was very timely considering the plans by the licensee to remove the stack during 1998. Practice in this exercise provided good training in preparation for stack removal.
A critique of the drill by the licensee Coq 'Jded that all drill objectives had been met. The emergency response organization utilized good communications and chain-of-command, which minimized confusion. Recovery operations were well thought out. Monitoring was conducted in case radiological conditions changed. A number of issues were noted by the controllers including the lack of a second company vehicle for the radiological team,
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lack of emphasis on the search and rescue aspects of the response, difficulty in determining who filled each emergency position, and lack of initial beta monitoring by the field team. The critique also identified that the maintenance team dispatched to the top of boiler No. 2 to report the conditbn of the reactor fuel buildinq roof did not have dosimetry. This could be a sigmficant problem during an actual emergency. Resolution of the issue concerning issuance of dosimetry to emergency personnel and other site personnel remaining onsite during a radiological emergency condition will be reviewed during a future inspection (IFl 50-133/9801-002).
The NRC periodically issues information notices and generic letters which may have applicability to shutdown plants. During this inspection a review was conducted of the-licensee's process for reviewing and dispositioning generic NRC correspondence to utilities. The licensee had a formal proceduralized process for evaluating the applicability of NRC information to Humboldt Bay and tracked issues that require action. Humboldt Bay Procedure HBAP A-21, " Plant Review of Regulatory Correspondence and Operating Expcience information," Revision 3, provided the process for handling NRC bulletins, circulare. notices, and generic letters. NRC information was processed and distributed by the Diiector, Licensing and Design Basis Management at Diablo Canyon. Issues that
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were gene-ic to Humboldt Bay were provided to the Humboldt Bay Plant Staff Review Committee for disp-a. The Plant Staff Review Committee minutes of the meeting for January 29,1998, were reviewed. During this meeting a number of NRC correspondence documents were reviewed including inNnhation Notices 97-79 through 97-88, and NRC Generic Letters 97-05 and 97-N A ' tacking system was used by the licensee to track any items determined applicable to Humboldt Bay.
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l Computers used at nuclear facilities face the generic problem of the year 2000 issue (some computer software may not properly recognize the date of 2000). PGAE had established a task force to address this problem at all PG&E facilities including Humboldt Bay. Selected personnel at Humboidt Bay had been designated to interface with the task force to assess the site impact. The security system computer was one of the computerized systems that was being evaluated.
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1.3 Conclusions i
The current plant status was reviewed and found to be consistent with their NRC approved SAFSTOR Decommissloring Plan.
PG&E was found to be in compliance wit. the Technical Specifications related to quarterly refueling building inspections, refueling building vent sy5 tem tests, reactor caisson sump monthly sampling, plant review committee, and sito emergency planning related to conducting an annual exercise.
The 1997 annual exercise was conducted November 14,1997. All objectives of the exercise were determined to have been successfully met by the licensee.
The licensee had a procedural process in place to review genent documents issued by the NRC to determine their applicability to the Humboldt Bay site. The Plant Staff Review Committee determined whether actions were necessary and utilized a tracking system to follow action items until closure.
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PG&E had established a task force to evaluate the impact of the year 2000 issue for computer software. Humboldt Bay was interfacing with the PG&E task force concerning specific site computer systems.
Safety Reviews, Design Changes, and Modifications (37801)
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A review was performed of selected documentation of activities, changes, tests, and experiments to verify that proper evaluations were completed for compliance with NRC regulations in 10 CFR 50.59 and that no unreviewed safety questions were involved with such activities.
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2.2 Observations and Findinas -
On July 29,1996, the NRC revised its decommissioning regulations to codify the use of 10 CFR 50.59 by licensees of permanently shut down power reactors. The revised decommissioning regulations contained a new requirement in 10 CFR 50.82(a)(6) that precludes licensees from performing decommissioning activities that:
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foreclose the release of the site for possible unrestricted use; (ii)
result in significant environmentalimpacts not previously reviewed; or (iii) result in there no longer being reasonable assurance that adequate funds will be available for decommissioning.
The licensee's administrative procedures for performing safety evaluations were
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reviewed. During an inspection conducted on May 13-15 and August 26-28,1997, the licensee's procedures were found not to clearly include the above provisions of
10 CFR 50.82(a)(6). Since that inspection, the licensee had issued a revision to Procedure HBAP C-19, Volume 1, * Licensing Bases impact Evaluation," dated September 4,1997. The revised procedure was found to adequately address the requirements of 10 CFR 50.82(a)(6).
Licensees are allowed to make changes to the Part 50 reactor programs and facilities using the provisions of 10 CFR 50.59, provided that the changes do not involve an
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unreviewed safety question. Procedure HBAP C-19, Revision 5, provided guidance to staff personnel performing these evaluations. The licensee's procedure was appropriate in that it properly guided the preparation, independent reviews and approval of safety evaluations to determine whether an unreviewed safety question was involved in proposed activities.
Brief reviews of the screening evaluations and the safety evaluations for the following activities were completed:
Design Change Package C-418, " Caisson Leak Sealant Injection," Revision 0
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SAFSTOR Equipment Removal Authorization HB3-004," Remove the Remote
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Valve Operators and Supports from the Demineralizer Control Board Area Formerly Used for the Condensate Demineralizer and Air Ejectors," Revision 0 SAFSTOR Equipment Removal Authorization HB3-006," Remove 2-inch
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Demineralizer Water Line to Cleanup Demineralizer * Revision 0 SAFSTOR Equipment Removal Authorization HB3-007," Remove 8" Low
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Pressure Core Flooding Piping Between +12' and -14' Elevation," Revision 0 DCN HB3-EC-407, " Access to Suppression Chamber at -66'," Revision 0
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Procedure Change HBAP A-13," Fire Loss Prevention Program"
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Procedure Change HBAP B-13,"Quahfication and Training Requirements of Fire
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Loss Prevention Personnel'
Procedure Change STP 3.20.2," Monthly Fire System Checks"
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All screening evaluations and safety evaluations reviewed were prepared in accordance with the appropriate procedure and were adequate and in compliance with applicable NRC regulatior.s.
2.3 Conclusions Acceptable programs were being implemented to ensure that activities, changes, tests, and experiments were properly evaluated for compliance with NRC requirements in 10 CFR 50.59 and that no unreviewed cafety questions were involved with such activities.
Spent Fuel Pool Safety (60801)
3.1 Insoection Scooe The condition of the spent fuel pool and compliance with Technical Specifications for water chemistry were evaluated. A review of commitments made in 1994 concerning actions to prevent freezing of systems related to the spent fuel pool were reviewed.
3.2 Observations and Findinas During this inspection, the spent fuel pool cover was removed to allow for a visual inspection of the condition of the spent fuel poolinterior and the clarity of the water.
Water clarity was very good A visualinspection of the condition of the fuel indicated that the fuel racks and fuel were in good condition. No problems were observed related to the condition of the spent fuel pool.
The spent fuel pool was a reinforced concrete structure located inside the refueling building. A stainless steelliner completely covered the inside surface of the spent fuel storage pool with a nominal gap of 1/4 inch between the liner and the walls and floor. A liner gap pump and collection system was operational for the space between the concrete wt. and the stainless steel liner. There were 390 fuel assemblies currently stored in the pool. All assemblies were zirconium clad. The demineralizer system operated continuously; however, the cooling system was shutdown in 1985. Water temperature was 80'F. Cecay heat was estimated at 89 watts / assembly in 1984.
A number of Technical Specifications applied to the spent fuel pool. Technical Specification Ill.B.2.a required the water level in the spent fuel pool to be maintained at an elevation of 10.5 feet. This was 1.5 feet below the main floor of the refueling building.
Observation of the water level during the inspection of the pool indicated that this requir"
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398, through January 21,1998. Water level had been maintained above the required 10.5 feet. Typical water level was 11 feet.
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Technical Specification Ill.B.2.b estabiished water quality requirements for the pool water, Sampling and confirmation of the Technical Specification was required monthly for pH, chlorides, conductivity, and Cs 137 levels. Licensee Procedure STP 3.6.5,
- Monthly Spent Fuel Pool Water Quality Check," Revision 39, established a program for complying with Technical Specification Ill.B.2.b. This procedure described the sampling process, documentation requirements, and acceptance criteria. The pH was required to be maintained between 5.3 and 6.5. A computerized summary of the monthly records for pH was reviewed for the period of January 1995 through December 1997. The pH was maintained within the required limits with typical pH levels at 5.7 to 5.9. Conductivity was required to be maintained below 10 mho/cm. For the period between January 1995 and December 1997, the conductivity was maintained below the Technical Specification limit Typicallevels were between 0.3 to 0.5 umho/cm. The highest value in 1997 was 0.6 umho/cm. The Technical Specification limit for Cs 137 was 1 X 10d uCl/rrl maximum. For 1997, typical Cs-137 levels were around 1.5 X 10 uCi/mi with the highest value of 2.05 X 10 5 uCl/ml.
Technical Specification Ill.B.2.a established a limit for the amount of water that could be allowed to accumulate in the spent fuel pool liner gap. This limit was 9 inches elevation which equated to 0.75 feet of water accumulated in the gap. Records were reviewed for January 4 through January 21,1998, and indicated that the gap water level had been maintained within the Technical Specification limit. In order to maintain the water level in the gap within technical specifications, the accumulated water had to be periodically pumped out. In January 1998, water had been pumped out of the gap approximately every 4 to 5 days. The in-leakage into the liner gap appeared to be coming from groundwater as well as from the spent fuel pool water. The in-leakage had been determined by the licensee to be about 1 gallen/ day.
Technical Specification IV.B.2.b required the liner gap pump to be tested monthly. The licensee had developed Procedure STP 3.6.1, " Spent Fuel Pool Liner Gap Pump Operability Verification," Revision 34, to verify monthly that the liner gap purnp was maintained operational. Records were not reviewed for this test since the pump was currently being operated on a weekly basis. The water removed frem the liner gap had low levels of radioactivity. The Cs-137 levels were showing a steady decrease from year to year. For December 1997, the Cs 137 levels were approximately 2.5 X 10~5 uCi/ml.
3.3 ConcluitaOS The spent fuel pool cover was removed during this inspection to allow for a visual examination of the water clarity and spent fuel condition. Water clarity was very good.
Visual observation of the fuel and the inside of the spent fuel pool indicated that the spent fuel was being properly stored.
Sper' Qel pool water chemistry, pool water level, and liner gap water level were reviewed during this inspection and were found to be within required Technical SpecifWion Cold Weather Preparations (71714)
4.1 insoection Srope in 1994 the NRC issued Bulletin 94 01, * Potential Fuel Pool Draindown Caused by inadequate Maintenance Practices at Dresden Unit 1." This guidance directed nuclear reactor facilities to review freezing potential for spent fuel pools and take ac' ions to prevent conditions that could result in loss of the spent fuel pool water inventory. This inspection reviewed actions that had been committed to by the licensee to confirm that necessary freeze protection was still in place.
4.2 Observations and Findings Requirements for freeze protection for the Humboldt Bay spent fuel pool were minimal.
Because of mi!d weather for the area and the lack of spent fuel pool systems exposed to the open weather, special heating or protection requirements were not necessary.
On May 9 and October 5,1994, the NRC conducted inspections of the Humboldt Bay facility t0 review applicability of NRC Bulletin 94-01 to the spent fuel pool at Unit No. 3.
The conclusion of the NRC inspection was that spent fuel pool problems related te freezing were very unlikely. On May 16,1994, PG&E issued a letter to the NRC disCJssing their evaluation of Bulletin 94-01 and identifying proposed actions related to ensuring that the water inventory would not be lost from the spent fuel pool due to a freezing problem. Actions were identified related to ensuring two drain line valves were maintained closed. A review of Humboldt Bay Procedure HBAP C-9 No.1, Attachment 2.2, " Sealer. Valve List," Revision 25, found that both valves were still on the list and identified as required to be kept closed.
4.3 Conclusions No significant potential freezing problems had been identified for the spent fuel pool and associated systems. Commitments made by PG&E in 1994 concerning valve positions for two spent fuel pool water drain lines were confirmed as still being included in the sealed valve list and identified as required to be maintained closed.
Decommissioning Performance and Status Review (71801)
5.1 Insoection Scoce The status of the Hurr.boldt Bay Unit No. 3 facility was reviewed against the description in the approved Decommissioning Plan. A tour of the facility was conducted to evaluate the structural condition of the facility, fire loading, housekeeping, and radiological control __
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5.2 Observations and Findinos t
The Humboldt Bay facility was being maintained in accordance with the NRC approved Decommissioning Plan. PG&E was evaluating several potential changes to the facility and was in the process of developing updates to the PSDAR to replace the current Decommissioning Plan to be more consistent with the new decommissioning regulations.
The most significant change being considered for the site was the removal of the 260 foot stack adjacent to the reactor fuel building. The stack would be removed in sections down to a level below the roof of the reactor fuel building and be replaced with a new shorter stack. The inside of the current stack was slightly contaminated.
The most significant activity recently completed at the Humboldt Bay Unit No. 3 facility was the repair of the caisson in-leakage. This effort was completed on September 6, 1997. On September 11,1997, the licensee reported to the NRC that the leak had been repaired and water in-leakage was negligible. The status of the lea.k was reviewed during this inspection. The in-leakage rate was approximately 15 gallons / day. This was a substantial reduction from the 6,500 gallons / day in-leakage occurring immediately before the leak was repaired. The 15 gallons / day rate had remained steady for the past 4 months and indicated that the caisson in-leakage problem had been successfully mitigated.
' Technical Specification Vll.C 3 required the licensee to maintain a plant fire brigade at the Humboldt Bay facility; however, no specific fire brigade requirements were outlined other than the number of members for the fire brigade. The licensee had recently revised Procedure TBD-003,' Fire Protection Engineering Fire Hazards Evaluation Fire Brigade Capability," dated January 15,1998. The changes established an onsite incipient fire brigade and relied on response from the local offsite fire department for fighting internal structural fires. In revising Procedure TBD-003, the licensee reviewed the fire hazards currently onsite for all areas associated with Unit No. 3, the periodic inspection and surveillance program, the existing fire suppression systems, and the response time and fire capabilit) of the Humboldt, Eureka, Arcata and Fortuna fire departments. The licensee concluded that changing the fire brigade from a structural brigade to an incipient brigade would not reduce the effectiveness of responding to a fire.
An independent review was completed by M&M Loss _ Protection Consultants which confirmed the licensee's conclusions.
A tour of the Humboldt Bay facility was completed during this inspection. The facility appeared to be in good structural condition. Housekeeping was good. No fire loading or OSHA concems were identified. Radiological posting requirements appeared to be correctly implemented.
5.3 Conclusions The Humboldt Bay facility was being maintained in a SAFSTOR condition in accordance with the approved Decommissioning Plan.
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The repair of the caisson groundwater in-leakage appeared to have been successful.
The repair was completed approximately 4 months prior to the inspection. Since the repairs were completed, the rate of in leakage had remained negligible.
Radioactive Waste Treatment, Effluent and Environmental Monitoring (84750)
6.1 Insoection Scooe Several monitoring wells around the Humboldt Bay facility were sampled and analyzed periodically for radioactivity. One of the wells had routinely indicated very low levels of tritium. Recently, a second well was found to have very low tritium levels. This inspection reviewed the current conditions related to the two wells.
6.2 Observations and Findinas Technical Specification V.A.6 required the licensee tr. maintain five groundwater
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monitoring wells in the vicinity of Unit No. 3. Two wells, MW-1 and MW-11, served as background wells which were hydrologically upgradient from the facility. Three wells, MW 2, MW-4, and MW 6, were located dom gradient from Unit No. 3 and served as groundwater contamination detection wells. Technical Specification V.B.6.c required the groundwater from these wells to be analyzed for gross alpha, gross beta, total gamma activity, and tritium. The three down gradient wells have never shown tritium levels.
However, the upgradient well No.11 had historically shown very low levels of tritium since sampling was begun in the mid-1980s.
Technical Specification Table W1 established a reporting level for tritium of 30,000 picocuries per liter (pCi/l). NUREG 1302, "Offeite Dose Calculation Manual Guidance:
2ndard Radiological Effluent Controls for Boiling Water Reactors," Table 4.12-1,
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wtablished a lower limit of detection (LLD) for tritium of 2,000 pCi/l, For water not used as drinking water, this limit was raised to 3,000 pCl/l. Longer count times have been used by Humboldt Bay to detect tritium below the required LLD and down to levels of 500 pCill Data for monitoring well MW-11 for the period from 1993 to 1997 was reviewed.
Tritium had never been detected above the required LLD of NUREG-1302 or the technical specification reporting levels in any of the wells. However, the licensee's increased counting time had resulted in the detection of tntium at levels in well No.11 ranging from 1400 pCl/lin 1993 to 500-600 pCillin 1997. The sample taken on August 19,1997, from well No.11 was below the 500 pCi/l value. However, monitoring well MW-1, which had previously r.ever shown tritium levels, measured 589 pCill on a sample taken on August 19,1997. Though these detected levels are very low and well below reporting levels, the licensee had identified the need to understand the source of the tritium to support future decommissioning planning of the site.
Humboldt Bay was continuing to evaluate the monitoring well results to determine the
. potential sources for the tritium. Follow up on the tritium issue will be conducted in a -
future inspection to assess the licensee's conclusions concerning the source of the tritium (IFl 50-133/98001-03).
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Qonclusions
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Tritium had _been historically detected in very low levels in one of the monitoring wells -
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onsite. The August 1997 sampling results indicated tritium in a second well that had q
historically not shown tritium. The licensee is currently evaluating this new data.
7-Followasp of Open items (97001,97002)
7.1 (Closed) IFl 50133/94001-03: This item crsceTied the problem of caisson in-leakage.
- As described in Section 5.2 of this report, the caisson in-leakage had been repaired by the licensee. Over 4 months had possed since completion of the repair effort with the in-leakage remaining constant at 15 gallons / day. This is down from the 6,500 gallons / day in-leak-e prior to the repair effort. The in-leakage problem had been ongoing since 1992 and coquired a significant repair effort which was completed on September 6,1997. The licensee grouted under the west suppression chamber floor to fill the leak pathway. This process appeared to have been successful in reducing the leak to negligible levels.
7.2 ~ - (Chaad) Violation 50-133/97002-01: Incorrect alarm setting on process monitor. On
April 15,1997, while a senior control operator was performing the weekly test of the process monitor, he discovered that the low and high alarms had been set to 41,000 cpm and 300,000 cpm, respectively, on the 1M scale. Technical Specifx:stion V.B.2.b required the high alarm to be set at a Cs-137 concentration limit of 1 X 1M Ci/ml. The incorrect high alarm setting for the process monitor equated to 9.78 X 10d Ci/ml. In response to this violation, the licensee took corrective actions including providing additional training to the operators and revising Procedure 3.21.3, " Weekly Process Monitor Checks." Training had been completed in April 1997. The revision to
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Procedure 3.21.3 ws.s complated and the procedure issued November 13,1997. A special precaution had been added to the procedure concoming the use of the correct i
~ scale during tests. The procedure also changed the process for conducting the test.
L Setting the alarm to zero as part of the test was no longer required. The test was P
conducted without resetting the alarms, thereby eliminating the step that had resulted in
the operator resetting the alarm point to the wrong level at the end of the test.
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8 Exit Meeting
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The inspectors presented the inspection re'.,ults to members of the licensee management at the exit meeting on January 29,1998. The licensee ack_nowledged the findings -
1:
- presented. The licensee did not identify as proprietary any information provided to, or reviewed by, the inspector.
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ATTACHMENT PARTIAL LIST OF PERSONS CONTACTED Licensen A. Arago, Community Affairs L. Brown, Radiation Protection Consultant M. Grossman, Operations Supervisor E. Kahler, Decommissioning Project Manager T. Moulia, Plant Manager J. Paul, Fire Marshall T. Rasmussen, Senior Power Production Engineer G. Rueger, Vice President, Nuclear Power Generation D. Sokolsky, Senior Licensing Engineer T. Tyler, Maintenance Supervisor R. Willis, Plant Engineer INSPECTION PROCEDURES USED 36801 Organization, Management, and Cost Controls 37801 10 CFR 50.59 Safety Evaluation Program 60801 Spent Fuel Pool Safety 71714 Cold Weather Preparations 71801 Decommissioning Performance and Status Review 84750 Radwaste Treatment and Effluent and Environmental Monitoring 92701 Follow up on Open items 92702 Follow up on Corrective Actions for Violations and Deviations ITEMS OPENED, CLOSED, AND DISCUSSED Ooened 50 133/98001 01 IFl Neutron Absorber Analysis 50 133/98001-02 IFl Dosimetry issuance During Radiological Emergencies 50-133/98001-03 IFl Tritium in Monitoring Wells MW 11 and MW-1 Clocad 50-133/94001-03 IFl Caisson Sump in-leakage 50-133/97002-01 VIO Incorrect Alarm Setting on Process Monitor
, Discussed None i
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LIST OF ACRONYMS CFR Code of Federal Regulations IFl
_ inspection Follow-up Item LLD Lower Limit of Detection mR milliroentgen NRC Nuclear Regulatory Commission OSHA Occupational Safety and Health Administration PG&E Pacific Gas & Electric PSDAR Post Shutdown Decommissioning Activities Report uCi microcurie VIO Violation k
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