ML20215D958
| ML20215D958 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/10/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20215D948 | List: |
| References | |
| NUDOCS 8612170154 | |
| Download: ML20215D958 (4) | |
Text
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o UNITED STATES g
8 NUCLEAR REGULATORY COMMISSION c.
WASHINGTON, D. C. 20555 4
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SAFETYEVALUATIONBYTHEOFFICEOFNUCLEARREACTORREGULAkION SUPPORTING AMEdDMENT NO.131 TO FACILITY LICENSI O. DPR-62 CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT UNIT 2 DOCKET NO. 50-324 1.0,Ih1RC[l'C 701 By submittal dated August 22 and December 2,1986, the Carolina Power and Light Company has proposed a Technical Specification change to permit a temporary increase in the Brunswick Steam Electric Plant, Unit No. 2 main steam line high radiation scram and isolation setpoints.
This change would facilitate the planned testing of hydrogen addition water chemistry at their Brunswick Plant Unit 2.
On the basis of prior experience, it is anticipated that the main steam line radiation levels may increase during the test by a factor of five over the routinely experienced dose rates.
2.0 EVALUATION 2.1 HIGH RADIATION SCRAM AND ISOLATION SETPOINTS The Main Steam Line Radiation Monitors (MSLRMs) provide reactor scram as well as reactor vessel and primary containment isolation signals upon detection of high activity levels in the main steam lines. Additionally, these monitors serve to limit radioactivity released in the event of fuel failures. The proposed Technical Specification changes (to Tables 2.2.1-1, 3.3.2-1 and 3.3.2-2) would allow adjustments to the normal back-ground radiation level and associated trip setpoints for the MSLRMs at reactor power levels greater than 22% of rated power. The adjustments are needed to accommodate the expected increase in main steam activity levels as a result of planned tests involving hydrogen injection into the primary system. This is primarily due to increased nitrogen-16 (N-16) levels in the reactor coolant.
The licensee states that the only transient or postulated accident which takes credit for the main steam line high radiation scram and isolation signals is the control rod drop accident (CRDA). The staff notes that for a CRDA, the MSLRMs' primary function is to limit the transport of activity released from failed fuel to the turbine and condensers. This is done by initiating closure of the main steam isolation valves and thus isolating the reactor vessel. Main steam line high radiation will also produce a reactor scram signal (reactor scram in the event of a CRDA, however, would be g2QQQ h P
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initiated by signals from.the Neutron Monitoring System) and itill isolate the mechanical vacuum pump and the gland seal steam exhaust system to
' reduce leakage of fission products to the atmosphere from the turbine and condensers.
Generic analysis of the consequences of a CRDA have shown that fuel failures are not expected to result from a CRDA occurring at greater than 10% power.. As power. increases, the severity of the rod accident rapidly decreases due to the effects of increased void formation and increased Doppler reactivity feedback. Since the-setpoint adjustments will be restricted to power levels above 22% of rated power, the staff concludes that the' currently approved CRDA analysis for Brunswick 2 is appropriately bounded and remains valid.
2.2 RADIATION PROTECTION /ALARA The staff also has reviewed the proposed Technical Specification change in reference to the radiological implications of the dose rate increases associated with N-16 equilibrium changes during hydrogen addition at BWRs.
In addition, the review addressed the radiation protection /ALARA measures for the' course of the planned test, in accordance with 10 CFR 20.1(c) and Regulatory Guide 8.8, "Information Relevant to Ensuring that Occupational Radiation Exposures at Nuclear Power Stations Will Be As Low As Is Reason-l ably Achievable."
An overall objective of the test is to determine general in-plant and site 4
boundary dose rate increases due to hydrogen addition. The licensee has c
indicated that normal health physics /ALARA practices and procedures for Brunswick will be continued throughout the test. Additionally, the licensee has indicated that specific locations will be identified where temporary shielding may be needed for long-term implementation of hydrogen injection.
The staff also has reviewed the licensee's proposed dose control measures e
and surveillance efforts planned for the hydrogen addition test. Tests of i
this type have been proposed and conducted at other operating BWRs follow-ing staff review and approval of similar Technical Specification changes.
The test conditions, as identified by the licensee, as well as the mea-sures proposed for radiation protection /ALARA at the Brunswick Steam 4
Electric Plant, Unit No. 2, are consistent with those utilized at the other BWRs during their successful hydrogen' addition tests. None of these tests involved any significant, unanticipated, radiological exposures or 4
releases.
2.3 HYDR 0 GEN STORAGE AND DISTRIBUTION SYSTEM L
h The licensee's hydrogen addition system is designed to reduce the poten-tial hazard to safety related systems and meets the applicable parts of the BWR Owners Group report, " Guidelines for Permanent BWR Hydrogen Water Chemistry Installations". The hydrogen addition system is being supplied i
by a new vendor, Innovative Technologies, Inc. All previous hydrogen water chemistry preimplementation tests have been performed by one other vendor.
l
P i f i Innovative Technologies, Inc. has extensive hydrogen water chemistry system experience on Swedish Reactor Plants.
The hydrogen injected into the condensate booster pump suction is stored as compressed gas in tube tank trucks. The hydrogen distribution system contains an excess flow check valve to limit the release of hydrogen in the event of a pipe break.
To prevent the accumulation of combustible levels of hydrogen in the condensate booster pump rooms, at the pumps, near the control valves, and along hydrogen supply line, the hydrogen lines will be leak tested prior to the test and will be monitored for hydrogen concentrations during the test. These monitors will alarm and isolate the hydrogen supply when hydrogen concentrations exceed 2%.
Since the licensee stores substantial amounts of chlorine on site for the purpose of water treatment, the staff evaluated the potential synergistic effect associated with the storage of hydrogen. The combination of hydrogen gas and chlorine gas can explode in the presence of any form of energy, such as sunlight or heat (250 C). Therefore, it is prudent to maintain an adequate separation distance between the chlorine and hydrogen storage facilities. The hydrogen tube tank trucks will be parked a distance of 420 feet away from the chlorine tank car. The licensee has committed to limiting the closest approach the hydrogen supply truck will make to the chlorine tank car to approximately 300 feet.
In addition, any movement of the chlorine tank car will not be brought closer than approximately 300 feet from the hydrogen supply truck. The 300 foot separation distance is judged to be sufficient to prevent interaction in the unlikely event of a simultaneous chlorine and hydrogen release.
On the basis of the above provisions, we conclude that the licensee's hydrogen addition system meets Section C.S.d of Branch Technical Position CMEB 9.5.1 of NUREG 0800 and, is therefore, acceptable.
3.0 EVALUATION
SUMMARY
On the basis of the adequacy of the licensee's radiation protection /ALARA program, utilization of special surveys to monitor dose rates increases on site and at the site boundary, the capability to monitor for fuel fail-ures, as well as the success of eimilar efforts at other operating BWRs, the staff finds the licensee's request acceptable.
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? 4.0 ENVIRONf1 ENTAL CONSIDERATIONS j
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and cimages surveillance requirements. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of the amendment will not be inimical to the comon defense and security or to the health and safety of the public.
Principal Contributor:
M. Lamastra Dated:
December 10, 1986
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